Methods of forging steel

OpenAIRE

Pečoler, Primož

2014-01-01

The following work presents processes of steel forming, challenges when forging steel, forming machines suitable for forging and which choice of machine is most suitable for forging. We can separate steel forming to free forging and drop forging. Free forging can be divided to hand forging and machine forging. The correct choice of furnaces is also very important. We must reach correct temperature in the furnace for raw steel to melt with less scalings. In diploma I mentioned some machine...

Instant forgedUI starter

CERN Document Server

Luiz, Joseandro

2013-01-01

Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks.The book is a Starter guide to learning ForgedUI. This book will start by unfolding the installation and creating a simple application using Titanium and ForgedUI, followed by taking you through the features to model an engaging UI and generate multi-platform code with Titanium, while covering the best design practice for Apple and Android application development. Last but not least, you will also come across the available resources where you can

Comparison study of multistep forging and injection forging of automobile fasteners

OpenAIRE

Chen Senyong; Qin Yi

2015-01-01

In order to improve production efficiency, injection forging as a feasible approach was introduced to automobile fasteners production. In the study reported in this paper, two forging approaches, traditional multistep forging and injection forging, were analysed by using a finite element method. Using ABAQUS and DEFORM, some significant factors, namely, forging force, energy consumption, component accuracy and stress distribution in the die, were compared to explore the potential and challeng...

Development of integral type forgings for steam generator of nuclear power plant

International Nuclear Information System (INIS)

Suzuki, Komei; Sato, Ikuo; Murai, Etsuo

1992-01-01

The use of integral type steel forgings for the construction of pressure vessel enhances the structural integrity of components and makes the fabrication of components and the execution of in-service inspection (ISI) easier than those fabrication from plate and casting materials. Such steel forgings have been realized for steam generator (SG) for nuclear power plant as follows : (1) Forged shell ring : change from welding fabrication of formed plates to forging ; (2) Forged conical shell ring : ditto ; (3) Forged head integral with nozzles (s) : (i) Primary head : change from casting to forging ; (ii) Secondary head : change from welding fabrication of formed plates to forging. These steel forgings have been realized by recent development in manufacturing technologies, such as steel making, forging processes and heat treatment which are vital to the quality of steel forgings. Some examples of recent typical high quality steel forgings developed by the Japan Steel Works, Ltd. (JSW) are introduced, and the main points of the manufacturing technique and the quality attained are also described. (author)

Role of forgings in powder metallurgy industry

International Nuclear Information System (INIS)

Hayes, A.F.; DeRidder, A.J.

1975-01-01

Forging of powder metallurgy materials is discussed. Information and data are included on forging powder metallurgy W, Mo, In 100, Rene 95, Astroloy, Be, and Ti. It is noted that the combination of powder metallurgy and forging work provides the best product from standpoints of reproducibility, freedom from segregation, low scrap rate, and uniform mechanical properties. Experience is being used to develop contour forging from hot isostatic pressed billets or preforms. The quality of this product is under evaluation. Results show steady improvement and it is anticipated that continued effort will soon produce a reliable, less costly product. Forging can continue to be relied upon to correct subtle defects present in powder metallurgy material

Effect of technological parameters on formability of semi-solid rheological casting-forging 6061 alloy

Directory of Open Access Journals (Sweden)

Jianbo TAN

2016-02-01

Full Text Available The 6061 alloy cooling curve is determined by analysis software, and the 6061 semi-solid alloy is prepared by manual paddling process. The primary solid fraction is tested through prepared water quenched samples under different temperature. With H1F100 type servo press and cup type test mold, the forming of the 6061 semi-solid alloy rheological casting-forging is made. The influence of alloy temperature, forming pressure, upper mould temperature and holding time on the formability of 6061 alloy is researched. The results show that within the same set of mold completing casting and forging of the alloy is feasible. Along with the increase of the alloy temperature and the upper mould temperature, the formability of finished products becomes better. Under this experimentation, when the temperature of the semi-solid alloy is amongst 642 ℃ to 645 ℃ and the upper mould preheating temperature is amongst 200 ℃ to 300 ℃, casting defects such as cold insulation will form in the casting-forging sample of semi-solid 6061 alloy with the prolongation of holding time.

Development of production technology and investigation of quality for forged-welded turbine rotors of steel 25Kh2NVFA

International Nuclear Information System (INIS)

Borisov, I.A.; Merinov, G.N.; Slezkina, E.V.

1997-01-01

A study was made into mechanical properties and microstructure of turbine rotor components manufactured by forging and heat treated under various conditions. It is revealed that the optimal heat treatment of forgings must include double quenching with subsequent tempering at 630-640 deg C for 10-20 h. Forged and welded rotors should be tempered at 620-630 deg C for 50-100 h. Microscopic examination and mechanical tests showed that low alloy steel 25Kh2NMF can be successfully used for manufacturing rotors of high-, medium-and low-heat turbines

Development and efficiency assessment of process lubrication for hot forging

Science.gov (United States)

Kargin, S.; Artyukh, Viktor; Ignatovich, I.; Dikareva, Varvara

2017-10-01

The article considers innovative technologies in testing and production of process lubricants for hot bulk forging. There were developed new compositions of eco-friendly water-graphite process lubricants for hot extrusion and forging. New approaches to efficiency assessment of process lubricants are developed and described in the following article. Laboratory and field results are presented.

Adapted diffusion processes for effective forging dies

Science.gov (United States)

Paschke, H.; Nienhaus, A.; Brunotte, K.; Petersen, T.; Siegmund, M.; Lippold, L.; Weber, M.; Mejauschek, M.; Landgraf, P.; Braeuer, G.; Behrens, B.-A.; Lampke, T.

2018-05-01

Hot forging is an effective production method producing safety relevant parts with excellent mechanical properties. The economic efficiency directly depends on the occurring wear of the tools, which limits service lifetime. Several approaches of the presenting research group aim at minimizing the wear caused by interacting mechanical and thermal loads by using enhanced nitriding technology. Thus, by modifying the surface zone layer it is possible to create a resistance against thermal softening provoking plastic deformation and pronounced abrasive wear. As a disadvantage, intensely nitrided surfaces may possibly include the risk of increased crack sensitivity and therefore feature the chipping of material at the treated surface. Recent projects (evaluated in several industrial applications) show the high technological potential of adapted treatments: A first approach evaluated localized treatments by preventing areas from nitrogen diffusion with applied pastes or other coverages. Now, further ideas are to use this principle to structure the surface with differently designed patterns generating smaller ductile zones beneath nitrided ones. The selection of suitable designs is subject to certain geo-metrical requirements though. The intention of this approach is to prevent the formation and propagation of cracks under thermal shock conditions. Analytical characterization methods for crack sensitivity of surface zone layers and an accurate system of testing rigs for thermal shock conditions verified the treatment concepts. Additionally, serial forging tests using adapted testing geometries and finally, tests in the industrial production field were performed. Besides stabilizing the service lifetime and decreasing specific wear mechanisms caused by thermal influences, the crack behavior was influenced positively. This leads to a higher efficiency of the industrial production process and enables higher output in forging campaigns of industrial partners.

Development of forging technology for PWR primary piping

International Nuclear Information System (INIS)

Morin, F.; Badeau, J.P.; Lambs, R.

1996-01-01

The purpose of this presentation is to give information on the changes in the design and manufacture of Primary Piping for electronuclear boilers of the Pressurized Water Reactor type (PWR) which has resulted in the making of one-piece forged lines including stub pipes and arcs. The optimization of these items is aimed at improving the life of the new power stations as well as guaranteeing their safety, while reducing inspection and maintenance requirements in service. The demonstration of the manufacturing feasibility has just been completed. It has taken material form in the installation, on the CIVAUX 1 section, of the first one-piece cold leg in the world. It will shortly be followed by the installation on the CIVAUX 2 section of a complete loop of bent forged pipes. Therefore, this new know-how is going to be incorporated in the French Rules (RCC-M) and can be directly taken into consideration both in the next work to be done and in the design and definition of a future nuclear reactor

Tailorable Burning Behavior of Ti14 Alloy by Controlling Semi-Solid Forging Temperature.

Science.gov (United States)

Chen, Yongnan; Yang, Wenqing; Zhan, Haifei; Zhang, Fengying; Huo, Yazhou; Zhao, Yongqing; Song, Xuding; Gu, Yuantong

2016-08-16

Semi-solid processing (SSP) is a popular near-net-shape forming technology for metals, while its application is still limited in titanium alloy mainly due to its low formability. Recent works showed that SSP could effectively enhance the formability and mechanical properties of titanium alloys. The processing parameters such as temperature and forging rate/ratio, are directly correlated with the microstructure, which endow the alloy with different chemical and physical properties. Specifically, as a key structural material for the advanced aero-engine, the burn resistant performance is a crucial requirement for the burn resistant titanium alloy. Thus, this work aims to assess the burning behavior of Ti14, a kind of burn resistant alloy, as forged at different semi-solid forging temperatures. The burning characteristics of the alloy are analyzed by a series of burning tests with different burning durations, velocities, and microstructures of burned sample. The results showed that the burning process is highly dependent on the forging temperature, due to the fact that higher temperatures would result in more Ti₂Cu precipitate within grain and along grain boundaries. Such a microstructure hinders the transport of oxygen in the stable burning stage through the formation of a kind of oxygen isolation Cu-enriched layer under the burn product zone. This work suggests that the burning resistance of the alloy can be effectively tuned by controlling the temperature during the semi-solid forging process.

Study on the isothermal forging process of MB26 magnesium alloy adaptor

Directory of Open Access Journals (Sweden)

Xu Wenchen

2015-01-01

Full Text Available The isothermal forging process is an effective method to manufacture complex-shaped components of hard-to-work materials, such as magnesium alloys. This study investigates the isothermal forging process of an MB26 magnesium alloy adaptor with three branches. The results show that two-step forging process is appropriate to form the adaptor forging, which not only improves the filling quality but also reduces the forging load compared with one-step forging process. Moreover, the flow line is distributed along the contour of the complex-shaped adaptor forging.

THE FORMING OF MAGNESIUM ALLOY FORGINGS FOR AIRCRAFT AND AUTOMOTIVE APPLICATIONS

Directory of Open Access Journals (Sweden)

Anna Dziubińska

2016-09-01

Full Text Available The paper presents the theoretical and technological aspects of forming magnesium alloy parts for aircraft and automotive applications. The main applications of magnesium alloys in the aircraft and automotive industries are discussed. In addition, the forging technology for magnesium alloys is generally described, with a particular emphasis on wrought alloys. A brief outline of the state of the art in the forging of magnesium alloys is given based on a survey of the specialist literature and the results of previous research by the authors.

Properties of powder metallurgy steel forgings

International Nuclear Information System (INIS)

Crowson, A.; Anderson, F.E.

1977-01-01

The effects of processing variables on the mechanical properties of heat-treated powder metallurgy (P/M) steel forgings were determined. Prealloyed 4600 steel powder blended with graphite to yield 4640 was compacted into preforms and hot forged in a warm, closed die. Variables studied were preform density, method of lubrication, preform sintering (time, temperature and atmosphere), forging pressure (20 and 40 tsi) and temperature (1850 0 F, 2000 0 F and 2200 0 F), and forging ratio (0.75 and 0.95). Relationships between interconnected porosity and total porosity for the various preform densities were determined. High density compacts required higher sintering temperatures due to the restricted mobility of the reducing gases in the pores. Die wall lubrication was comparable to admixed lubrication, and it simplified powder mixing and preform sintering operations. Forgings with densities from 99 to 99.8 percent of theoretical density were attained with a forging pressure of 20 to 40 tsi and preform temperatures of 2000 0 F and above. At forging conditions which resulted in forgings with acceptable mechanical properties, complete die fill was accomplished at a forging ratio of 0.95, whereas incomplete die fill resulted at a forging ratio of 0.75. The response of P/M forgings to heat treatment was comparable to that for wrought materials, and the resultant tensile and yield strengths were equivalent to the strength values described for wrought 4640 steel in AMS specification 6317B. In addition, ductility and impact properties of P/M forgings with near theoretical density (99.5+ percent) were comparable to bar stock forgings

The structural and phase state formed in construction titanium alloy by radial forging

Energy Technology Data Exchange (ETDEWEB)

Shlyakhova, Galina V.; Danilov, Vladimir I.; Orlova, Dina V.; Zuev, Lev B. [Institute of Strength Physics and Materials Science SB RAS, Tomsk (Russian Federation); Zavodchikov, Aleksandr S. [Perm State Technical University, Perm (Russian Federation)

2011-07-01

The feasibility of rod manufacture from construction titanium alloy using radial forging on a high duty machine SXK16 was investigated. The investigations were carried on for titanium rod samples using the methods of metallography, electron transmission microscophy and X-ray analysis. The results obtained are described herein. It is found that radial forging results in the formation of homogeneous fine-grained structure.Using radial forging process, high-quality items are produced. As-worked material has submicrocrystalline globular structure and an optimal α:β phase ratio. Besides, the technology is more cost-effective relative to conventional flow charts. Key words: forging, titanium alloy, fine-grain structure, substructure, pore size.

Research into Oil-based Colloidal-Graphite Lubricants for Forging of Al-based Alloys

International Nuclear Information System (INIS)

Petrov, A.; Petrov, P.; Petrov, M.

2011-01-01

The presented paper describes the topical problem in metal forging production. It deals with the choice of an optimal lubricant for forging of Al-based alloys. Within the scope of the paper, the properties of several oil-based colloidal-graphite lubricants were investigated. The physicochemical and technological properties of these lubricants are presented. It was found that physicochemical properties of lubricant compositions have an influence on friction coefficient value and quality of forgings.The ring compression method was used to estimate the friction coefficient value. Hydraulic press was used for the test. The comparative analysis of the investigated lubricants was carried out. The forging quality was estimated on the basis of production test. The practical recommendations were given to choose an optimal oil-based colloidal-graphite lubricant for isothermal forging of Al-based alloy.

Study on the microstructure of the different parts for new aluminum alloy forgings

International Nuclear Information System (INIS)

Gao Wei; Zheng Xiaojing; Wu Fu

2014-01-01

The mechanical properties of former aluminium alloy forgings cannot achieve technique demand. Because the component, dimension and preparation technology of new aluminum alloy have changed, the microstructure and mechanical properties of forgings are researched. It is concluded that the flowline of forgings has good continuity and uniformity, it does not have a prominent difference on microhardness of different parts. The results prove that the microstructure of forgings has good consistency. The matrix structure of forgings consists of fiber texture and equiaxed structure. The residual second phases, which are harmful to mechanical properties, are observed in the equiaxed structure. The center of equiaxed structure core zone, the edge of equiaxed structure transition zone and equiaxed structure edge zone should be focus on observing test, they are the sampling location of tensile property. (authors)

Forging evaluaion of 304L stainless steel

International Nuclear Information System (INIS)

Packard, C.L.; Edstrom, C.M.

1979-01-01

The objective of this project was to evaluate and characterize the effects of various forging parameters on the metallographic structure and mechanical properties of 304L stainless steel forgings. Upset and die forgings were produced by hammer and Dynapak forging with forging temperatures ranging from 760 to 1145 0 C, upset reductions ranging from 20 to 60%, and annealing times ranging from 0 to 25 minutes at 843 0 C. The carbide precipitation behavior observed was found to be a function of forging temperature and annealing time. Higher forging temperatures were beneficial in avoiding continuous carbide precipitation and annealing at 843 0 C promoted increased carbide precipitation. The yield strength of the unannealed forgings decreased with increasing forging temperature and, with the exception of the 1145 0 C upset forgings, was significantly lowered by annealing

Design and verification of thermomechanical parameters of P/M Ti6Al4V alloy forging

Energy Technology Data Exchange (ETDEWEB)

Wojtaszek, Marek, E-mail: mwojtasz@metal.agh.edu.pl; Śleboda, Tomasz

2014-12-05

Highlights: • Thermomechanical parameters of P/M Ti6Al4V alloy processing were determined. • The use of the mixture of elemental powders allows reducing manufacturing costs. • Numerical modelling allowed to elaborate favourable parameters of forging. • The industrial trials of hot forging of P/M Ti6Al4V alloy were successful. - Abstract: This work is focused on the design of technology of forging high-quality Ti6Al4V alloy by means of powder metallurgy methods. A mixture of elemental powders, with the chemical composition of that of Ti6Al4V alloy, was used as a starting material for the investigation. Powder mixtures were fully densified by hot compaction under precisely controlled conditions. The mechanical properties of the obtained compacts were examined. The mechanical behaviour of the investigated alloy powder compacts was evaluated by compression test under various thermomechanical conditions using Gleeble simulator. The microstructure of powder compacts as well as P/M alloy samples deformed in compression tests was examined. All data obtained from the experimental tests were applied as boundary conditions for numerical simulation of forging of selected forgings. Basing on the results of both plastometric tests and simulations, thermomechanical parameters of the investigated alloy forging were determined. Designed parameters of forging technology were verified by forging trials performed in industrial conditions. The quality of the obtained forgings was examined by means of computed tomography.

Design and verification of thermomechanical parameters of P/M Ti6Al4V alloy forging

International Nuclear Information System (INIS)

Wojtaszek, Marek; Śleboda, Tomasz

2014-01-01

Highlights: • Thermomechanical parameters of P/M Ti6Al4V alloy processing were determined. • The use of the mixture of elemental powders allows reducing manufacturing costs. • Numerical modelling allowed to elaborate favourable parameters of forging. • The industrial trials of hot forging of P/M Ti6Al4V alloy were successful. - Abstract: This work is focused on the design of technology of forging high-quality Ti6Al4V alloy by means of powder metallurgy methods. A mixture of elemental powders, with the chemical composition of that of Ti6Al4V alloy, was used as a starting material for the investigation. Powder mixtures were fully densified by hot compaction under precisely controlled conditions. The mechanical properties of the obtained compacts were examined. The mechanical behaviour of the investigated alloy powder compacts was evaluated by compression test under various thermomechanical conditions using Gleeble simulator. The microstructure of powder compacts as well as P/M alloy samples deformed in compression tests was examined. All data obtained from the experimental tests were applied as boundary conditions for numerical simulation of forging of selected forgings. Basing on the results of both plastometric tests and simulations, thermomechanical parameters of the investigated alloy forging were determined. Designed parameters of forging technology were verified by forging trials performed in industrial conditions. The quality of the obtained forgings was examined by means of computed tomography

Manufacturing and properties of closure head forging integrated with flange for PWR reactor pressure vessel

International Nuclear Information System (INIS)

Tomoharu Sasaki; Iku Kurihara; Etsuo Murai; Yasuhiko Tanaka; Koumei Suzuki

2003-01-01

Closure head forging (SA508, Gr.3 Cl.1) integrated with flange for PWR reactor pressure vessel has been developed. This is intended to enhance structural integrity of closure head resulted in elimination of ISI, by eliminating weld joint between closure head and flange in the conventional design. Manufacturing procedures have been established so that homogeneity and isotropy of the material properties can be assured in the closure head forging integrated with flange. Acceptance tensile and impact test specimens are taken and tested regarding the closure head forging integrated with flange as very thick and complex forgings. This paper describes the manufacturing technologies and material properties of the closure head forging integrated with flange. (orig.)

Kinematics at the Main Mechanism of a Railbound Forging Manipulator

Directory of Open Access Journals (Sweden)

Florian Ion Tiberiu Petrescu

2015-09-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Heavy payload forging manipulators are mainly characterized by large load output and large capacitive load input. The relationship between outputs and inputs will greatly influence the control and the reliability. Forging manipulators have become more prevalent in the industry today. They are used to manipulate objects to be forged. The most common forging manipulators are moving on a railway to have a greater precision and stability. They have been called the railbound forging manipulators. In this paper we analyze the general kinematics of the main mechanism from a such manipulator. Kinematic scheme shows a typical forging manipulator, with the basic motions in operation process: walking, motion of the tong and buffering. The lifting mechanism consists of several parts including linkages, hydraulic drives and motion pairs. The principle of type design from the viewpoints of the relationship between output characteristics and actuator inputs is discussed. An idea of establishing the incidence relationship between output characteristics and actuator inputs is proposed. These novel forging manipulators which satisfy certain functional requirements provide an effective help for the design of forging manipulators.

A two-step superplastic forging forming of semi-continuously cast AZ70 magnesium alloy

Directory of Open Access Journals (Sweden)

Pan Wang

2015-03-01

Full Text Available A two-step technology combined forging with superplastic forming has been developed to enhance the forgeability of semi-continuously cast AZ70 magnesium alloy and realize the application of the as-cast magnesium alloy in large deformation bullet shell. In the first step, fine-grained microstructure preforms that are suitable for superplastic forming were obtained by reasonably designing the size of the initial blanks with the specific height-to-diameter ratio, upsetting the blanks and subsequent annealing. In the second step, the heat treated preforms were forged into the end products at the superplastic conditions. The end products exhibit high quality surface and satisfied microstructure. Consequently, this forming technology that not only avoids complicating the material preparation but also utilizes higher strain rate superplastic provides a near net-shaped novel method on magnesium forging forming technology using as-cast billet.

Computer Οptimization of Geometric Form of Tool and Preform for Closed-die Forging of Compressor Blade Simulator

Directory of Open Access Journals (Sweden)

A. V. Botkin

2014-07-01

Full Text Available Using the software package DEFORM 3D when developing technology of isothermal forging workpiece blades it is possible to reduce the pre-production time, to improve the quality of forgings and increase lifetime of forging dies. Computer modeling allows to predict the formation of such defects during forging as notches and wrinkles, underfilling of die impression, to estimate tool loads. Preform shape and angular position of the blade simulator were optimized in order to minimize the lateral forces generated during the forging operation.

Modelling of defects in ingot forging

DEFF Research Database (Denmark)

Christiansen, Peter

The present report presents an investigation of the ingot forging process with special emphasis on modelling the influence of die geometry on the soundness of the ingot after hot forging. An investigation on how to model damage is also performed. The influence of the lower die angle is quantified...... angle of 130o-140o giving rise to the largest centreline porosity closure regardless of material hardening behaviour applied. Friction was found only to have minor influence on the optimum. Multi stroke forging operations have also been modelled since the ingot forging process consists of many forging...... damage. It is found that when evaluating damage only by relative density; feed size and lower die angle does not influence whether the hot forging process is successful or not. This is in disagreement with the general understanding of the ingot forging process. When evaluating ductile damage...

Forging Industry Leadtimes: An Analysis of Causes for and Solutions to Long Leadtimes for Aerospace Forgings

Science.gov (United States)

1986-09-01

Pamplet . Forging Industry Association, Cleveland-MT, uncatea. 20. Forging Industry Association, and American Society for Metals. Forging Handbook, edited... Pamplet . The Harris-Thomas Drop Forge Compnyayto--n R, undated. 43. Theeck, Michael F., TECH MOD Program Mana.er. Personal interview. Industrial Base... Brochure . Worcester MA, 3, . 125 "’ VITA Captain Stephen F. O’Neill was born on 19 June 1957 in Pittsfield, Massachusetts. He graduated from high school

A-508 class 3 forgings for pressure vessels

International Nuclear Information System (INIS)

Comon, J.

1977-01-01

The manufacture of the forged parts of the first PWR nuclear pressure vessel installed in France started in the Creusot-Loire's Forge Plant in 1961. Since this date, more than 300 forgings of this type were delivered (flanges, rings, zones, and nozzles). The major part of these forgings were made of Mn, Ni, Mo steel (SA 508 class 3). They represent a population large and homogeneous enough to attempt a statistical analysis of chemical and mechanical test results. The aim of this analysis was double: (1) a better knowledge of the scattering of the results and a better estimate of what can be introduced or accepted in a specification, and (2) the setting up of correlations existing between these results, particularly between chemical analysis and mechanical test results. In addition to this statistical analysis concerning industrial results, several laboratory studies are presented, giving a more complete characterization of SA 508 class 3. All these results form a very complete documentation showing that SA 508 class 3 steel is suitable for the manufacture of large forged vessels requiring a high degree of reliability

Analysis of alternative technologies stamping compressor blades of marine engines

Directory of Open Access Journals (Sweden)

Олександр Сергійович Аніщенко

2015-10-01

Full Text Available The author has made an analysis of several technologies stamping forgings compressor blades from titanium alloy ВT3-1. These technologies use different types of forming equipment: crank hot press, high-speed hammers, screw presses with hydraulic drive (SPHD, as well as isothermal forging hydraulic press. He pointed out the main advantages and disadvantages of the technology, noting that high-speed punching in the shipbuilding industry of Ukraine is not used for the manufacture of forgings blades. The article contains an economic analysis of the cost of forgings blades, which are made on four technologies: punching and calibration to crank hot press, stamping and calibration to press for isothermal forging, stamping and calibration on SPHD-press, stamping on SPHD-press and calibration to press for isothermal forging. The author has identified the effective use of these technologies. He showed that the use of SPHD-presses and hydraulic presses for isothermal forging reduces the cost of forging on the average 12% in comparison with the technology at the crank hot stamping press, increases the utilization of metal 1,3-1,5 times more, reduces power consumption 1,05-3,0 times less and complexity of manufacturing 1,8-4,2 times. However SPHD-press increases capital investment in the organization of stamping technology 2,6-5,3 times more and depreciation 2-4 times. Isothermal forging technology requires the cost of the stamps in 1,4-2,0 times higher than stamps for crank presses. The author argues that stamping forging blades technology improvement should be implemented saving basic materials first of all. Efficiency of isothermal stamping and calibration will be the higher, the more geometric dimensions of stamped forgings are

Microstructure Evolution and Surface Cracking Behavior of Superheavy Forgings during Hot Forging

Directory of Open Access Journals (Sweden)

Zhenhua Wang

2018-01-01

Full Text Available In recent years, superheavy forgings that are manufactured from 600 t grade ingots have been applied in the latest generation of nuclear power plants to provide good safety. However, component production is pushing the limits of the current free-forging industry. Large initial grain sizes and a low strain rate are the main factors that contribute to the deformation of superheavy forgings during forging. In this study, 18Mn18Cr0.6N steel with a coarse grain structure was selected as a model material. Hot compression and hot tension tests were conducted at a strain rate of 10−4·s−1. The essential nucleation mechanism of the dynamic recrystallization involved low-angle grain boundary formation and subgrain rotation, which was independent of the original high-angle grain boundary bulging and the presence of twins. Twins were formed during the growth of dynamic recrystallization grains. The grain refinement was not obvious at 1150°C. A lowering of the deformation temperature to 1050°C resulted in a fine grain structure; however, the stress increased significantly. Crack-propagation paths included high-angle grain boundaries, twin boundaries, and the insides of grains, in that order. For superheavy forging, the ingot should have a larger height and a smaller diameter.

Fractography analysis of tool samples used for cold forging

DEFF Research Database (Denmark)

Dahl, K.V.

2002-01-01

Three fractured tool dies used for industrial cold forging have been investigated using light optical microscopy and scanning electron microscopy. Two of the specimens were produced using the traditional Böhler P/M steel grade s790, while the lastspecimen was a third generation P/M steel produced...... using new technology developed by Böhler. All three steels have the same nominal composition of alloying elements. The failure in both types of material occurs as a crack formation at a notch inside ofthe tool. Generally the cold forging dies constructed in third generation steels have a longer lifetime...

Medium carbon vanadium micro alloyed steels for drop forging

International Nuclear Information System (INIS)

Jeszensky, Gabor; Plaut, Ronald Lesley

1992-01-01

Growing competitiveness of alternative manufacturing routes requires cost minimization in the production of drop forged components. The authors analyse the potential of medium carbon, vanadium microalloyed steels for drop forging. Laboratory and industrial experiments have been carried out emphasizing deformation and temperature cycles, strain rates and dwell times showing a typical processing path, associated mechanical properties and corresponding microstructures. The steels the required levels of mechanical properties on cooling after forging, eliminating subsequent heat treatment. The machinability of V-microalloyed steels is also improved when compared with plain medium carbon steels. (author)

Effect of Cold Forging on Microstructure and MechanicalProperties of Al/SiC Composites

Science.gov (United States)

Hanamantraygouda, M. B.; Shivakumar, B. P., Dr; Siddappa, P. N.; Sampathkumar, L.; Prashanth, L.

2018-02-01

The objective of this work was to investigate the effect of cold forging on mechanical properties and microstructural study of Al MMCs, at different wt% of SiC and forging cycle. The Al-SiC composite material was fabricated by stir casting method at different weight percentage of SiC such as 2.5, 5, 7.5 and 10%. Further, the deformation characteristics during open-die forging of Al-SiC composite at cold conditions was investigated. Cast and forged composite material was subjected to hardness test, tensile test and impact test. The grain size, microstructure behaviour was investigated using optical microscope. The results show that hardness and strength of Al-SiC composite increases and ductility decreases as compared to Al alloy in both as-cast and forged conditions. Optical microscope images showed that the distribution of SiC in Al matrix was more homogeneous in a forged composite as compared to cast one and reduction of porosity was found. Further, it showed that due to forging cycle the grain size was reduced by 30% to 35% from initial size.

Optical Forging of Graphene into Three-Dimensional Shapes.

Science.gov (United States)

Johansson, Andreas; Myllyperkiö, Pasi; Koskinen, Pekka; Aumanen, Jukka; Koivistoinen, Juha; Tsai, Hung-Chieh; Chen, Chia-Hao; Chang, Lo-Yueh; Hiltunen, Vesa-Matti; Manninen, Jyrki J; Woon, Wei Yen; Pettersson, Mika

2017-10-11

Atomically thin materials, such as graphene, are the ultimate building blocks for nanoscale devices. But although their synthesis and handling today are routine, all efforts thus far have been restricted to flat natural geometries, since the means to control their three-dimensional (3D) morphology has remained elusive. Here we show that, just as a blacksmith uses a hammer to forge a metal sheet into 3D shapes, a pulsed laser beam can forge a graphene sheet into controlled 3D shapes in the nanoscale. The forging mechanism is based on laser-induced local expansion of graphene, as confirmed by computer simulations using thin sheet elasticity theory.

Microstructural and mechanical evolutions during the forging step of the COBAPRESS, a casting/forging process

Science.gov (United States)

Perrier, Frédéric; Desrayaud, Christophe; Bouvier, Véronique

Aluminum casting/forging processes are used to produce parts for the automotive industry. In this study, we examined the influence of the forging step on the microstructure and the mechanical properties of an A356 aluminum alloy modified with strontium. Firstly, a design of samples which allows us to test mechanically the alloy before and after forging was created. A finite element analysis with the ABAQUS software predicts a maximum of strain in the core of the specimens. Observations with the EBSD technique confirm a more intense sub-structuration of the dendrite cells in this zone. Yield strength, ultimate tensile strength, elongation and fatigue lives were then improved for the casting/forging samples compared to the only cast specimens. The closure of the porosities and the improvement of the surface quality during the forging step enhance also the fatigue resistance of the samples.

Forging process design for risk reduction

Science.gov (United States)

Mao, Yongning

In this dissertation, forging process design has been investigated with the primary concern on risk reduction. Different forged components have been studied, especially those ones that could cause catastrophic loss if failure occurs. As an effective modeling methodology, finite element analysis is applied extensively in this work. Three examples, titanium compressor disk, superalloy turbine disk, and titanium hip prosthesis, have been discussed to demonstrate this approach. Discrete defects such as hard alpha anomalies are known to cause disastrous failure if they are present in those stress critical components. In this research, hard-alpha inclusion movement during forging of titanium compressor disk is studied by finite element analysis. By combining the results from Finite Element Method (FEM), regression modeling and Monte Carlo simulation, it is shown that changing the forging path is able to mitigate the failure risk of the components during the service. The second example goes with a turbine disk made of superalloy IN 718. The effect of forging on microstructure is the main consideration in this study. Microstructure defines the as-forged disk properties. Considering specific forging conditions, preform has its own effect on the microstructure. Through a sensitivity study it is found that forging temperature and speed have significant influence on the microstructure. In order to choose the processing parameters to optimize the microstructure, the dependence of microstructure on die speed and temperature is thoroughly studied using design of numerical experiments. For various desired goals, optimal solutions are determined. The narrow processing window of titanium alloy makes the isothermal forging a preferred way to produce forged parts without forging defects. However, the cost of isothermal forging (dies at the same temperature as the workpiece) limits its wide application. In this research, it has been demonstrated that with proper process design, the die

Performance Assessment Method for a Forged Fingerprint Detection Algorithm

Science.gov (United States)

Shin, Yong Nyuo; Jun, In-Kyung; Kim, Hyun; Shin, Woochang

The threat of invasion of privacy and of the illegal appropriation of information both increase with the expansion of the biometrics service environment to open systems. However, while certificates or smart cards can easily be cancelled and reissued if found to be missing, there is no way to recover the unique biometric information of an individual following a security breach. With the recognition that this threat factor may disrupt the large-scale civil service operations approaching implementation, such as electronic ID cards and e-Government systems, many agencies and vendors around the world continue to develop forged fingerprint detection technology, but no objective performance assessment method has, to date, been reported. Therefore, in this paper, we propose a methodology designed to evaluate the objective performance of the forged fingerprint detection technology that is currently attracting a great deal of attention.

29 CFR 1910.218 - Forging machines.

Science.gov (United States)

2010-07-01

... 29 Labor 5 2010-07-01 2010-07-01 false Forging machines. 1910.218 Section 1910.218 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.218 Forging machines. (a... other identifier, for the forging machine which was inspected. (ii) Scheduling and recording the...

Wear Analysis of Die Inserts in the Hot Forging Process of a Forked Type Forging Using Reverse Scanning Techniques

Directory of Open Access Journals (Sweden)

Łukasz Dworzak

2017-12-01

Full Text Available This article presents a wear analysis of die inserts used in the hot forging process of a forked forging (yoke, an element applied in steering systems of passenger vehicles. Studies involved the application of an original reverse scanning method intended for rapid and reliable wear analysis of forging tools (with complicated shape affording easy assessment without the need to dismount tools from the forging unit. The developed method involves analysis of progressive wear of forging tools based on measurements (scanning of forgings periodically collected from the process and constitutes a useful tool for measurement and testing. As the authors’ earlier works have demonstrated, the proposed new approach to analysis of tool wear with the application of reverse 3D scanning has proven successful in multiple instances in the case of axially symmetrical objects. The presented results of studies indicate that it is possible to utilize the expanded method to analyze the lifetime of forging tools, including tools with complex geometry. Application of the reverse scanning method allows for continuous and practical monitoring of the condition of forging tools over the course of the forging process and should have a positive impact on improving production output and reducing production costs.

48 CFR 225.7102 - Forgings.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Forgings. 225.7102 Section 225.7102 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... Forgings. ...

Examples on cold forged aluminium components in automotive industry

DEFF Research Database (Denmark)

Bay, Niels; Kolsgaard, A.

2000-01-01

The present paper describes the possibilites of applying cold forging for manufacturing of light weight components in aluminium. A short description of the basic cold forming processes forms the basis for describing the great variety in design of cold forged components. Examples are mainly taken ...... from automotive industry but in a few cases also from other industrial sectors to show the possibilities....

Distribution of Microstructure and Vickers Hardness in Spur Bevel Gear Formed by Cold Rotary Forging

Directory of Open Access Journals (Sweden)

Wuhao Zhuang

2014-11-01

Full Text Available Cold rotary forging is a novel metal forming technology which is widely used to produce the high performance gears. Investigating the microstructure and mechanical property of cold rotary forged gears has a great significance in improving their service performance. In this study, the grain morphology in different regions of the spur bevel gear which is processed by cold rotary forging is presented. And the distribution regulars of the grain deformation and Vickers hardness in the transverse and axial sections of the gear tooth are studied experimentally. A three-dimensional rigid-plastic FE model is developed to simulate the cold rotary forging process of a spur bevel gear under the DEFORM-3D software environment. The variation of effective strain in the spur bevel gear has been investigated so as to explain the distribution regulars of the microstructure and Vickers hardness. The results of this research thoroughly reveal the inhomogeneous deformation mechanisms in cold rotary forging of spur bevel gears and provide valuable guidelines for improving the performance of cold rotary forged spur bevel gears.

First Results of Energy Saving at Process Redesign of Die Forging Al-Alloys

International Nuclear Information System (INIS)

Pepelnjak, Tomaz; Kuzman, Karl; Kokol, Anton

2011-01-01

The contribution deals with eco-friendly solutions for shortened production chains of forging light alloys. During the die forging operations a remarkable amount of material goes into the flash and later on into chips during finish machining. These low value side products are rich with embedded energy therefore recycling or reprocessing could be very energy saving procedure.In cooperation with a die forging company a shortened reprocessing cycle has been studied starting from re-melting the forging flash and without additional heating to cast preforms for subsequent die forging. As such preforms have not as good formability characteristics as those done from extruded billets the isothermal forging process has been adopted. First results showed that without cracks and other defects the formability is sufficient for a broad spectrum of forgings.To improve the formability a homogenization process of cast preforms has been implemented. As the process started immediately after casting, amount of additional energy for heating was minimized. To reduce voids forging process was redesigned in a way to assure greater hydrostatic pressures in parts during forging. First results were promising therefore research is going towards improving processes without adding significantly more energy as it is needed for casting with homogenization and die forging.

Forging of Advanced Disk Alloy LSHR

Science.gov (United States)

Gabb, Timothy P.; Gayda, John; Falsey, John

2005-01-01

The powder metallurgy disk alloy LSHR was designed with a relatively low gamma precipitate solvus temperature and high refractory element content to allow versatile heat treatment processing combined with high tensile, creep and fatigue properties. Grain size can be chiefly controlled through proper selection of solution heat treatment temperatures relative to the gamma precipitate solvus temperature. However, forging process conditions can also significantly influence solution heat treatment-grain size response. Therefore, it is necessary to understand the relationships between forging process conditions and the eventual grain size of solution heat treated material. A series of forging experiments were performed with subsequent subsolvus and supersolvus heat treatments, in search of suitable forging conditions for producing uniform fine grain and coarse grain microstructures. Subsolvus, supersolvus, and combined subsolvus plus supersolvus heat treatments were then applied. Forging and subsequent heat treatment conditions were identified allowing uniform fine and coarse grain microstructures.

Sensitivity analysis and optimization algorithms for 3D forging process design

International Nuclear Information System (INIS)

Do, T.T.; Fourment, L.; Laroussi, M.

2004-01-01

This paper presents several approaches for preform shape optimization in 3D forging. The process simulation is carried out using the FORGE3 registered finite element software, and the optimization problem regards the shape of initial axisymmetrical preforms. Several objective functions are considered, like the forging energy, the forging force or a surface defect criterion. Both deterministic and stochastic optimization algorithms are tested for 3D applications. The deterministic approach uses the sensitivity analysis that provides the gradient of the objective function. It is obtained by the adjoint-state method and semi-analytical differentiation. The study of stochastic approaches aims at comparing genetic algorithms and evolution strategies. Numerical results show the feasibility of such approaches, i.e. the achieving of satisfactory solutions within a limited number of 3D simulations, less than fifty. For a more industrial problem, the forging of a gear, encouraging optimization results are obtained

Study on isothermal precision forging process of rare earth intensifying magnesium alloy

International Nuclear Information System (INIS)

Shan, Debin; Xu, Wenchen; Han, Xiuzhu; Huang, Xiaolei

2012-01-01

A three dimensional rigid-plastic finite element model is established to simulate the isothermal precision forging process of the magnesium alloy bracket based on DEFORM 3D in order to analyze the material flow rule and determine the forging process scheme. Some problems such as underfilling and too large forging pressure are predicted and resolved through optimizing the shapes of the billet successfully. Compared to the initial microstructure, the isothermal-forged microstructure of the alloy refines obviously and amounts of secondary phases precipitate on the matrix during isothermal forging process. In subsequent ageing process, large quantities of secondary phases precipitate from α-Mg matrix with increasing ageing time. The optimal comprehensive mechanical properties of the alloy have been obtained after aged at 473 K, 63 h with the ultimate tensile strength, tensile yield strength and elongation 380 MPa, 243 MPa and 4.07% respectively, which shows good potential for application of isothermal forging process of rare earth intensifying magnesium alloy.

Forging loads, deformation modes and fracture in axi-symmetrric closed die cold forging of sintered aluminium powder compacts

International Nuclear Information System (INIS)

Butt, M.A.; Ali, L.

2003-01-01

An experimental investigation into closed-die cold forging of sintered aluminium powder rod- shaped compacts was carried out. Axi-symmetric components were forged from sintered powder preforms with different initial diameter to height ratios. Different compaction pressures, sintering and lubrication conditions were used as variables during the investigations. Detailed observations were made on green/sintered density, compaction defects, forging loads, deformation modes and on the onset of fracture during progressive forging of sintered powder compacts. Experimental results obtained during the investigations have been presented and discussed in detail. (author)

Heavy forgings for reactor pressure vessels

International Nuclear Information System (INIS)

Cerjak, H.; Papouschek, F.

1979-01-01

The importance of forgings for an optimal design of nuclear components is described. Problems concerning the correlation of requirements, material behavior, fabrication and testing of forgings are discussed. (orig.) [de

Physical modeling and numerical simulation of V-die forging ingot with central void

DEFF Research Database (Denmark)

Christiansen, Peter; Hattel, Jesper Henri; Bay, Niels

2014-01-01

Numerical simulation and physical modeling performed on small-scale ingots made from pure lead, having a hole drilled through their centerline to mimic porosity, are utilized to characterize the deformation mechanics of a single open die forging compression stage and to identify the influence...... of the lower V-die angle on porosity closure and forging load requirements of large cast ingots. Results show that a lower V-die angle of 120 provides the best closure of centerline porosity without demanding the highest forging loads or developing unreasonably asymmetric shapes that may create difficulties...... in multi-stage open die forging procedures....

Nickel-base alloy forgings for advanced high temperature power plants

Energy Technology Data Exchange (ETDEWEB)

Donth, B.; Diwo, A.; Blaes, N.; Bokelmann, D. [Saarschmiede GmbH Freiformschmiede, Voelklingen (Germany)

2008-07-01

The strong efforts to reduce the CO{sub 2} emissions lead to the demand for improved thermal efficiency of coal fired power plants. An increased thermal efficiency can be realised by higher steam temperatures and pressures in the boiler and the turbine. The European development aims for steam temperatures of 700 C which requires the development and use of new materials and also associated process technology for large components. Temperatures of 700 C and above are too high for the application of ferritic steels and therefore only Nickel-Base Alloys can fulfill the required material properties. In particular the Nickel-Base Alloy A617 is the most candidate alloy on which was focused the investigation and development in several German and European programs during the last 10 years. The goal is to verify and improve the attainable material properties and ultrasonic detectability of large Alloy 617 forgings for turbine rotors and boiler parts. For many years Saarschmiede has been manufacturing nickel and cobalt alloys and is participating the research programs by developing the manufacturing routes for large turbine rotor forgings up to a maximum diameter of 1000 mm as well as for forged tubes and valve parts for the boiler side. The experiences in manufacturing and testing of very large forgings made from nickel base alloys for 700 C steam power plants are reported. (orig.)

Finite element analysis for temperature distributions in a cold forging

International Nuclear Information System (INIS)

Kim, Dong Bum; Lee, In Hwan; Cho, Hae Yong; Kim, Sung Wook; Song, In Chul; Jeon, Byung Cheol

2013-01-01

In this research, the finite element method is utilized to predict the temperature distributions in a cold-forging process for a cambolt. The cambolt is mainly used as a part of a suspension system of a vehicle. The cambolt has an off-centered lobe that manipulates the vertical position of the knuckle and wheel to a slight degree. The cambolt requires certain mechanical properties, such as strength and endurance limits. Moreover, temperature is also an important factor to realize mass production and improve efficiency. However, direct measurement of temperature in a forging process is infeasible with existing technology; therefore, there is a critical need for a new technique. Accordingly, in this study, a thermo-coupled finite element method is developed for predicting the temperature distribution. The rate of energy conversion to heat for the workpiece material is determined, and the temperature distribution is analyzed throughout the forging process for a cambolt. The temperatures associated with different punch speeds are also studied, as well as the relationships between load, temperature, and punch speed. Experimental verification of the technique is presented.

Finite element analysis for temperature distributions in a cold forging

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Bum; Lee, In Hwan; Cho, Hae Yong [Chungbuk National University, Cheongju (Korea, Republic of); Kim, Sung Wook [Yanbian National University, Yanbian (China); Song, In Chul; Jeon, Byung Cheol [Sunil dyfas, Jincheon (Korea, Republic of)

2013-10-15

In this research, the finite element method is utilized to predict the temperature distributions in a cold-forging process for a cambolt. The cambolt is mainly used as a part of a suspension system of a vehicle. The cambolt has an off-centered lobe that manipulates the vertical position of the knuckle and wheel to a slight degree. The cambolt requires certain mechanical properties, such as strength and endurance limits. Moreover, temperature is also an important factor to realize mass production and improve efficiency. However, direct measurement of temperature in a forging process is infeasible with existing technology; therefore, there is a critical need for a new technique. Accordingly, in this study, a thermo-coupled finite element method is developed for predicting the temperature distribution. The rate of energy conversion to heat for the workpiece material is determined, and the temperature distribution is analyzed throughout the forging process for a cambolt. The temperatures associated with different punch speeds are also studied, as well as the relationships between load, temperature, and punch speed. Experimental verification of the technique is presented.

Manufacturing and material properties of ultralarge size forgings for advanced BWRPV

International Nuclear Information System (INIS)

Suzuki, Komei; Sato, Ikuo; Tsukada, Hisashi

1994-01-01

Ultralarge size forgings for the advanced boiling water reactor (ABWR) pressure vessel as represented by the bottom petal made from a 600ton ingot have been developed. The bottom petal is a larger wall thickness ring with 10 integrated nozzles inside and outside the ring. The outer diameter is 7.8m, the height is 1.8m and the wall thickness if 1.1m in the as-forged condition. A very high purity level of P≤qslant0.003% and S≤qslant0.003% can be obtained by the application of double-refining processes to all the molten steel. The forging shows a homogeneous chemical distribution, sound internal qualities and adequate impact properties.This paper summarizes the manufacturing technique and material properties of large size forgings such as the bottom petal, the shell with integrated skirt and the bottom dome. ((orig.))

High yttria ferritic ODS steels through powder forging

Energy Technology Data Exchange (ETDEWEB)

Kumar, Deepak [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Prakash, Ujjwal, E-mail: ujwalfmt@iitr.ac.in [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Dabhade, Vikram V. [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Laha, K.; Sakthivel, T. [Mechanical Metallurgy Group, IGCAR, Kalpakkam, Tamilnadu 603102 (India)

2017-05-15

Oxide dispersion strengthened (ODS) steels are being developed for future nuclear reactors. ODS Fe-18%Cr-2%W-0.2%Ti steels with 0, 0.35, 0.5, 1 and 1.5% Y{sub 2}O{sub 3} (all compositions in weight%) dispersion were fabricated by mechanical alloying of elemental powders. The powders were placed in a mild steel can and forged in a stream of hydrogen gas at 1473 K. The steels were forged again to final density. The strength of ODS steel increased with yttria content. Though this was accompanied by a decrease in tensile elongation, all the steels showed significant ductility. The ductility in high yttria alloys may be attributed to improved inter-particle bonding between milled powders due to reduction of surface oxides by hydrogen. This may permit development of ODS steels with yttria contents higher than the conventional limit of 0.5%. It is suggested that powder forging is a promising route to fabricate ODS steels with high yttria contents and improved ductility. - Highlights: •ODS steels with yttria contents beyond the conventional limit of 0.5 wt% were fabricated by powder forging in a hydrogen atmosphere. •All the alloys exhibited significant ductility. •This may be attributed to improved inter-particle bonding due to reduction of surface oxides by hydrogen. •Strength in excess of 300 MPa was obtained at 973 K for 0.5%, 1% and 1.5% yttria ODS alloys. •Powder forging is a promising route to fabricate ODS steels and permits development of compositions with up to 1.5% yttria.

Research on damage evolution and damage model of 316LN steel during forging

Energy Technology Data Exchange (ETDEWEB)

Duan, X.W., E-mail: dxwmike1998@sina.com; Liu, J.S.

2013-12-20

The tensile tests and unloading tensile experiments of 316LN steel were conducted. The damage evolution processes were investigated by optical microscope. The fracture was studied using a Scanning Electron Microscope (SEM) and optical microscope, of which, the chemical compositions were analyzed by Energy Dispersive Spectrometer (EDS). The results show that voids nucleate by decohesion of Al{sub 2}O{sub 3} inclusions–matrix interface and mainly along the grain boundary, especially, at triangular grain boundary junctions. The tensile processes were simulated by Deform2D under different deformation conditions. The critical damage values were obtained. The model between the critical damage value, temperature and strain rate was established by regression analysis. A combination of numerical simulation and upsetting experiments was applied for verifying the accuracy and reliability of critical damage value. These damage values can be used to predict the initiation of voids during 316LN steel hot forging. So, they have important instructional effects on designing forging technology of 316LN steel.

High yttria ferritic ODS steels through powder forging

Science.gov (United States)

Kumar, Deepak; Prakash, Ujjwal; Dabhade, Vikram V.; Laha, K.; Sakthivel, T.

2017-05-01

Oxide dispersion strengthened (ODS) steels are being developed for future nuclear reactors. ODS Fe-18%Cr-2%W-0.2%Ti steels with 0, 0.35, 0.5, 1 and 1.5% Y2O3 (all compositions in weight%) dispersion were fabricated by mechanical alloying of elemental powders. The powders were placed in a mild steel can and forged in a stream of hydrogen gas at 1473 K. The steels were forged again to final density. The strength of ODS steel increased with yttria content. Though this was accompanied by a decrease in tensile elongation, all the steels showed significant ductility. The ductility in high yttria alloys may be attributed to improved inter-particle bonding between milled powders due to reduction of surface oxides by hydrogen. This may permit development of ODS steels with yttria contents higher than the conventional limit of 0.5%. It is suggested that powder forging is a promising route to fabricate ODS steels with high yttria contents and improved ductility.

Hot forging of roll-cast high aluminum content magnesium alloys

Science.gov (United States)

Kishi, Tomohiro; Watari, Hisaki; Suzuki, Mayumi; Haga, Toshio

2017-10-01

This paper reports on hot forging of high aluminum content magnesium alloy sheets manufactured using horizontal twin-roll casting. AZ111 and AZ131 were applied for twin-roll casting, and a hot-forging test was performed to manufacture high-strength magnesium alloy components economically. For twin-roll casting, the casting conditions of a thick sheet for hot forging were investigated. It was found that twin-roll casting of a 10mm-thick magnesium alloy sheet was possible at a roll speed of 2.5m/min. The grain size of the cast strip was 50 to 70µm. In the hot-forging test, blank material was obtained from as-cast strip. A servo press machine with a servo die cushion was used to investigate appropriate forging conditions (e.g., temperature, forging load, and back pressure) for twin-roll casts (TRCs) AZ111 and AZ131. It was determined that high aluminum content magnesium alloy sheets manufactured using twin-roll casting could be forged with a forging load of 150t and a back pressure of 3t at 420 to 430°C. Applying back pressure during hot forging effectively forged a pin-shaped product.

Developments of steel fabrication processes for castings and ingots for forgings

International Nuclear Information System (INIS)

Fernandez, S.

1980-01-01

This chapter deals with a series of technological developments in the manufacture of steels which have occurred during the last years, in particular reporting the results obtained in Reinosa with some of these methods in the fabrication of castings as well as forgings and rolled products. (author)

Press forging and optical properties of lithium fluoride

Science.gov (United States)

Ready, J. F.; Vora, H.

1980-07-01

Lithium fluoride is an important candidate material for windows on high power, short-pulse ultraviolet and visible lasers. Lithium fluoride crystals were press forged in one step over the temperature range 300 to 600 C to obtain fine grained polycrystalline material with improved mechanical properties. The deformation that can be given to a lithium fluoride crystal during forging is limited by the formation of internal cloudiness (veiling) with the deformation limit increasing with increasing forging temperature from about 40 percent at 400 C to 65 percent at 600 C. To suppress veiling, lithium fluoride crystals were forged in two steps over the temperature range 300 to 600 C, to total deformations of 69 to 76 percent, with intermediate annealing at 700 C. This technique yields a material which has lower scattering with more homogeneous microstructure than that obtained in one step forging. The results of characterization of various optical and mechanical properties of single crystal and forged lithium fluoride, including scattering, optical homogeneity, residual absorption, damage thresholds, environmental stability, and thresholds for microyield are described.

Press forging and optical properties of lithium fluoride

International Nuclear Information System (INIS)

Ready, J.F.; Vora, H.

1979-01-01

Lithium fluoride is an important candidate material for windows on high-power, short-pulse ultraviolet and visible lasers. Lithium fluoride crystals have been press forged in one step over the temperature range 300 to 600 0 c to obtain fine-grained polycrystalline material with improved mechanical properties. The deformation that can be given to a lithium fluoride crystal during forging is limited by the formation of internal cloudiness (veiling) with the deformation limit increasing with increasing forging temperature from about 40% at 400 0 C to 65% at 600 0 C. To suppress veiling, lithium fluoride crystals were forged in two steps over the temperature range 300 to 600 0 C, to total deformations of 69-76%, with intermediate annealing at 700 0 C. This technique yields a material which has lower scattering with more homogeneous microstructure than that obtained in one-step forging. The results of characterization of various optical and mechanical properties of single-crystal and forged lithium fluoride, including scattering, optical homogeneity, residual absorption, damage thresholds, environmental stability, and thresholds for microyield are described

Quality assurance for hammer forgings

International Nuclear Information System (INIS)

Potthast, E.

1984-01-01

The quality assurance program introduced by Arbed Saarstahl and laid down in a quality assurance manual is described. A particular attention is attached thereby both to quality practice proper and to a reliable flow of information amongst all the persons involved. The production and test sequence schedules of the hammer forging plant are illustrated by the example of a forged valve housing for nuclear power plants. These schedules specify not only the forging process in the individual production stages but also the workpiece contour after each working operation, the heat treatment, the furnace charging, and the inspection of finished parts. The formalization of the tests is designed both to promote the customer's trust towards the supplier and to prevent the formal operations involved from hindering further technical development. (orig.) [de

Co-Operative Training in the Sheffield Forging Industry

Science.gov (United States)

Duncan, R.

2008-01-01

Purpose: The purpose of this paper is to give details of an operation carried out in Sheffield to increase the recruitment of young men into the steel forging industry. Design/methodology/approach: The Sheffield Forges Co-operative Training Scheme was designed to encourage boys to enter the forging industry and to provide them with training and…

Design and Analysis of a Forging Die for Manufacturing of Multiple Connecting Rods

Science.gov (United States)

Megharaj, C. E.; Nagaraj, P. M.; Jeelan Pasha, K.

2016-09-01

This paper demonstrates to utilize the hammer capacity by modifying the die design such that forging hammer can manufacture more than one connecting rod in a given forging cycle time. To modify the die design study is carried out to understand the parameters that are required for forging die design. By considering these parameters, forging die is designed using design modelling tool solid edge. This new design now can produce two connecting rods in same capacity hammer. The new design is required to validate by verifying complete filing of metal in die cavities without any defects in it. To verify this, analysis tool DEFORM 3D is used in this project. Before start of validation process it is require to convert 3D generated models in to. STL file format to import the models into the analysis tool DEFORM 3D. After importing these designs they are analysed for material flow into the cavities and energy required to produce two connecting rods in new forging die design. It is found that the forging die design is proper without any defects and also energy graph shows that the forging energy required to produce two connecting rods is within the limit of that hammer capacity. Implementation of this project increases the production of connecting rods by 200% in less than previous cycle time.

22 CFR 121.10 - Forgings, castings and machined bodies.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles on the U.S. Munitions List include articles in a partially completed state (such as forgings...

27 CFR 447.22 - Forgings, castings, and machined bodies.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles on the U.S. Munitions Import List include articles in a partially completed state (such as forgings...

Development of strategies for saving energy by temperature reduction in warm forging processes

Science.gov (United States)

Varela, Sonia; Santos, Maite; Vadillo, Leire; Idoyaga, Zuriñe; Valbuena, Óscar

2016-10-01

This paper is associated to the European policy of increasing efficiency in raw material and energy usage. This policy becomes even more important in sectors consuming high amount of resources, like hot forging industry, where material costs sums up to 50% of component price and energy ones are continuously raising. The warm forging shows a clear potential of raw material reduction (near-net-shape components) and also of energy saving (forging temperature under 1000°C). However and due to the increment of the energy costs, new solutions are required by the forging sector in order to reduce the temperature below 900°C. The reported research is based on several approaches to reduce the forging temperature applied to a flanged shaft of the automotive sector as demonstration case. The developed investigations have included several aspects: raw material, process parameters, tools and dies behavior during forging process and also metallographic evaluation of the forged parts. This paper summarizes analysis of the ductility and the admissible forces of the flanged shaft material Ck45 in as-supplied state (as-rolled) and also in two additional heat treated states. Hot compression and tensile tests using a GLEEBLE 3800C Thermo mechanical simulator have been performed pursuing this target. In the same way, a coupled numerical model based on Finite Element Method (FEM) has been developed to predict the material flow, the forging loads and the stresses on the tools at lower temperature with the new heat treatments of the raw material. In order to validate the previous development, experimental trials at 850 °C and 750 °C were carried out in a mechanical press and the results were very promising.

The State of the Art in Cold Forging Lubrication

DEFF Research Database (Denmark)

Bay, Niels

1994-01-01

The manufature of components in steel, aluminium and copper alloys by cold forging production has increased ever since the 1950's. Typical processes are forward rod extrusion and backward can extrusion, upsetting, ironing, tube extrusion and radial extrusion. The tribological conditions in cold...... forging are extremely severe due to large surface expansion and normal pressure in the tool/workpiece interface combined with elevated tool temperatures. Except for the more simple cold forging operations successful production therefore requires advanced lubrication systems. The present paper gives...... a detailed description of the state of art for lubricant systems for cold forging of C-steels and low alloy steels as well as aluminium alloys including all the basic operations such as cleaning of the slugs, application of eventual conversion coating and lubrication. As regards cold forging of steel...

Experimental and numerical research on forging with torsion

Science.gov (United States)

Petrov, Mikhail A.; Subich, Vadim N.; Petrov, Pavel A.

2017-10-01

Increasing the efficiency of the technological operations of blank production is closely related to the computer-aided technologies (CAx). On the one hand, the practical result represents reality exactly. On the other hand, the development procedure of new process development demands unrestricted resources, which are limited on the SMEs. The tools of CAx were successfully applied for development of new process of forging with torsion and result analysis as well. It was shown, that the theoretical calculations find the confirmation both in praxis and during numerical simulation. The mostly used constructional materials were under study. The torque angles were stated. The simulated results were evaluated by experimental procedure.

Analysis of the thermo-mechanical deformations in a hot forging tool by numerical simulation

International Nuclear Information System (INIS)

L-Cancelos, R.; Varas, F.; Viéitez, I.; Martín, E.

2016-01-01

Although programs have been developed for the design of tools for hot forging, its design is still largely based on the experience of the tool maker. This obliges to build some test matrices and correct their errors to minimize distortions in the forged piece. This phase prior to mass production consumes time and material resources, which makes the final product more expensive. The forging tools are usually constituted by various parts made of different grades of steel, which in turn have different mechanical properties and therefore suffer different degrees of strain. Furthermore, the tools used in the hot forging are exposed to a thermal field that also induces strain or stress based on the degree of confinement of the piece. Therefore, the mechanical behaviour of the assembly is determined by the contact between the different pieces. The numerical simulation allows to analyse different configurations and anticipate possible defects before tool making, thus, reducing the costs of this preliminary phase. In order to improve the dimensional quality of the manufactured parts, the work presented here focuses on the application of a numerical model to a hot forging manufacturing process in order to predict the areas of the forging die subjected to large deformations. The thermo-mechanical model developed and implemented with free software (Code-Aster) includes the strains of thermal origin, strains during forge impact and contact effects. The numerical results are validated with experimental measurements in a tooling set that produces forged crankshafts for the automotive industry. The numerical results show good agreement with the experimental tests. Thereby, a very useful tool for the design of tooling sets for hot forging is achieved. (paper)

Analysis of the thermo-mechanical deformations in a hot forging tool by numerical simulation

Science.gov (United States)

L-Cancelos, R.; Varas, F.; Martín, E.; Viéitez, I.

2016-03-01

Although programs have been developed for the design of tools for hot forging, its design is still largely based on the experience of the tool maker. This obliges to build some test matrices and correct their errors to minimize distortions in the forged piece. This phase prior to mass production consumes time and material resources, which makes the final product more expensive. The forging tools are usually constituted by various parts made of different grades of steel, which in turn have different mechanical properties and therefore suffer different degrees of strain. Furthermore, the tools used in the hot forging are exposed to a thermal field that also induces strain or stress based on the degree of confinement of the piece. Therefore, the mechanical behaviour of the assembly is determined by the contact between the different pieces. The numerical simulation allows to analyse different configurations and anticipate possible defects before tool making, thus, reducing the costs of this preliminary phase. In order to improve the dimensional quality of the manufactured parts, the work presented here focuses on the application of a numerical model to a hot forging manufacturing process in order to predict the areas of the forging die subjected to large deformations. The thermo-mechanical model developed and implemented with free software (Code-Aster) includes the strains of thermal origin, strains during forge impact and contact effects. The numerical results are validated with experimental measurements in a tooling set that produces forged crankshafts for the automotive industry. The numerical results show good agreement with the experimental tests. Thereby, a very useful tool for the design of tooling sets for hot forging is achieved.

An empirical model for friction in cold forging

DEFF Research Database (Denmark)

Bay, Niels; Eriksen, Morten; Tan, Xincai

2002-01-01

With a system of simulative tribology tests for cold forging the friction stress for aluminum, steel and stainless steel provided with typical lubricants for cold forging has been determined for varying normal pressure, surface expansion, sliding length and tool/work piece interface temperature...... of normal pressure and tool/work piece interface temperature. The model is verified by process testing measuring friction at varying reductions in cold forward rod extrusion. KEY WORDS: empirical friction model, cold forging, simulative friction tests....

40 CFR 467.40 - Applicability; description of the forging subcategory.

Science.gov (United States)

2010-07-01

... forging subcategory. 467.40 Section 467.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY Forging Subcategory § 467.40 Applicability; description of the forging subcategory. This subpart applies to discharges of...

Sintering and densification; new techniques: sinter forging

International Nuclear Information System (INIS)

Winnubst, A.J.A.

1998-01-01

In this chapter pressure assisted sintering methods will be described. Attention will mainly be paid to sinter forging as a die-wall free uniaxial pressure sintering technique, where large creep strains are possible. Sinter forging is an effective tool to reduce sintering temperature and time and to obtain a nearly theoretically dense ceramic. In this way grain size in tetragonal zirconia ceramics can be reduced down to 100 nm. Another important phenomenon is the reduction of the number density and size of cracks and flaws resulting in higher strength and improved reliability, which is of utmost importance for engineering ceramics. The creep deformation during sinter forging causes a rearrangement of the grains resulting in a reduction of interatomic spaces between grains, while grain boundary (glassy) phases can be removed. The toughness and in some cases the wear resistance is enhanced after sinter forging as a result of the grain-boundary-morphology improvement. (orig.)

Effect of Laser Preheating AISI 4140 Specimens for Micro-Forging

Directory of Open Access Journals (Sweden)

Jung C.

2017-06-01

Full Text Available Many high performance and permanent service parts require suitable material characteristics-high fatigue strength is one of the most important characteristics. For this reason, surface treatment processes are essential to increase the material performance and avoid the use of costly ineffective material. There exist various surface treatment processes for various applications. Each process has advantages and disadvantages and hybridization can solve various problems. The micro-forging process delivers a controlled and uniform surface hardness, but the depth of the forged surface is limited. On the other hand, laser heat treatment can increase the hardness drastically, but the surface may become brittle, which reduces the fatigue life. Laser-assisted micro-forging is a novel hybrid process of laser heat treatment and micro-forging that has the potential to increase the forging depth and relax the stress caused by the high temperature of the forging process.

Effect of forging process on microstructure, mechanical and corrosion properties of biodegradable Mg-1Ca alloy

International Nuclear Information System (INIS)

Harandi, Shervin Eslami; Hasbullah Idris, Mohd; Jafari, Hassan

2011-01-01

Research highlights: → Forging temperature demonstrates more pronounced effect compared to forging speed. → Precipitation of Mg 2 Ca phase at grain boundaries accelerates corrosion rate. → Forging process doesn't provide the corrosion resistance required for bone healing. -- Abstract: The performance of Mg-1Ca alloy, a biodegradable metallic material, may be improved by hot working in order that it may be of use in bone implant applications. In this study, Mg-1Ca cast alloy was preheated to different temperatures before undergoing forging process with various forging speeds. Macro- and microstructure of the samples were examined by stereo and scanning electron microscopes (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), respectively. To determine the mechanical properties of the alloy, hardness value and plastic deformation ability of the samples were measured. To investigate the corrosion behaviour of the alloy, immersion and electrochemical tests were performed on the samples in simulated body fluid and the corrosion products were characterized by SEM/EDS. The results showed that increasing forging temperature decreased grain size led to improved hardness value and plastic deformation ability of the alloy, whereas no significant effect was observed by changing forging speed. Moreover, forging at higher temperatures led to an increase in the amount of Mg 2 Ca phase at grain boundaries resulted in higher corrosion rates. It can be concluded that although forging process improved the mechanical properties of the alloy, it does not satisfy the corrosion resistance criteria required for bone healing.

48 CFR 252.225-7025 - Restriction on acquisition of forgings.

Science.gov (United States)

2010-10-01

... of forgings. 252.225-7025 Section 252.225-7025 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.225-7025 Restriction on acquisition of forgings. As prescribed in 225.7102-4, use the following clause: Restriction on Acquisition of Forgings (DEC 2009) (a...

Effect of ultrasonic cold forging technology as the pretreatment on the corrosion resistance of MAO Ca/P coating on AZ31B Mg alloy

Energy Technology Data Exchange (ETDEWEB)

Chen, Lingling, E-mail: daisy_chenlingling@163.com [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Gu, Yanhong, E-mail: gu_yanhong@163.com [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Liu, Lu, E-mail: liulu@bipt.edu.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Liu, Shujing, E-mail: liushujing@bipt.edu.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Hou, Binbin, E-mail: sohu19880815@126.com [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Liu, Qi, E-mail: 13521196884@sina.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Ding, Haiyang, E-mail: dinghaiyang@bipt.edu.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China)

2015-06-25

Highlights: • Ultrasonic cold forging technology was used as the pretreatment for MAO coating. • Nano layer with the grain size of 30–80 nm was formed on the UCFT treated surface. • Calcium phosphate contained coating was obtained by MAO process. • The remained nano layer underlying MAO coating could impact the corrosion resistance greatly. - Abstract: A calcium phosphate contained (Ca/P) coating was obtained on AZ31B Mg alloy by micro-arc oxidation (MAO) process under the pretreatment of ultrasonic cold forging technology (UCFT). The surface nanograins were introduced after UCFT pretreatment on AZ31B Mg alloy. Optical microscope (OM) was employed to observe the microstructures of the untreated and UCFT treated samples. Transmission electron microscopy (TEM) and atomic force microscope (AFM) were employed to observe the microstructures of nanograins and the surface roughness of the UCFT treated Mg alloys. The grain size of the UCFT treated Mg alloy is 48.67 nm and the surface roughness is 17.03 nm. The microstructures and the phase compositions of MAO samples were observed and analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The XRD results show that the coating include Ca/P phase, including hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}), HA), tertiary calcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}, TCP) and calcium phosphate dehydrate (CaHPO{sub 4}⋅2H{sub 2}O, DCPD). The hardness of the samples was measured by the micro-hardness tester under the loads of 10 g, 25 g and 50 g. 3D topographies of hardness indenter were characterized by 3D profiler. The immersion tests and potentiodynamic polarization tests were used to evaluate the weight loss rate and corrosion current density in simulated body fluid (SBF). The results show that the corrosion resistance of Ca/P MAO coating on Mg alloy was improved greatly by the pretreatment of UCFT.

Analysis of reforming process of large distorted ring in final enlarging forging

International Nuclear Information System (INIS)

Miyazawa, Takeshi; Murai, Etsuo

2002-01-01

In the construction of reactors or pressure vessels for oil chemical plants and nuclear power stations, mono block open-die forging rings are often utilized. Generally, a large forged ring is manufactured by means of enlarging forging with reductions of the wall thickness. During the enlarging process the circular ring is often distorted and becomes an ellipse in shape. However the shape control of the ring is a complicated work. This phenomenon makes the matter still worse in forging of larger rings. In order to make precision forging of large rings, we have developed the forging method using a v-shape anvil. The v-shape anvil is geometrically adjusted to fit the distorted ring in the final circle and reform automatically the shape of the ring during enlarging forging. This paper has analyzed the reforming process of distorted ring by computer program based on F.E.M. and examined the effect on the precision of ring forging. (author)

Transmission electron microscopy of Ti-12Mo-13Nb Alloy aged after heat forging

International Nuclear Information System (INIS)

Oliveira, Nathalia Rodrigues; Baldan, Renato; Gabriel, Sinara Borborema

2014-01-01

Metastable β-Ti alloys possess mechanical properties, in particular a elastic modulus that depends not only on its composition but also the applied thermomechanical treatments. These alloys require high mechanical strength and a low Young’s modulus to avoid stress shielding. Preliminary studies on the development of Ti- 13Nb-12Mo alloy showed than the better properties were obtained at aged at 500 ° C / 24 h after cold forging , whose microstructure consisted of bimodal α phase in the β matrix. In this work, Ti-12Mo-13Nb alloy was heat forged and aged at 500 deg C for 24h and the microstructure was analyzed by employing X-ray diffraction and transmission electron microscopy. According to the results, while the cold forging resulted in bimodal α phase in the β matrix, hot forging resulted in a fine and homogeneous α phase in the β matrix. (author)

Structural changes of radial forging die surface during service under thermo-mechanical fatigue

International Nuclear Information System (INIS)

Nematzadeh, Fardin; Akbarpour, Mohammad Reza; Kokabi, Amir Hosein; Sadrnezhaad, Seyed Khatiboleslam

2009-01-01

Radial forging is one of the modern open die forging techniques and has a wide application in producing machine parts. During operation at high temperatures, severe temperature change associated with mechanical loads and the resultant wearing of the die surface lead to intense variation in strain on the die surface. Therefore, under this operating condition, thermo-mechanical fatigue (TMF) occurs on the surface of the radial forging die. TMF decreases the life of the die severely. In the present research, different layers were deposited on a 1.2714 steel die by SMAW and GTAW, with a weld wire of UDIMET 520. The microstructure of the radial forging die surface was investigated during welding and service using an optical microscope and scanning electron microscope. The results revealed that, after welding, the structure of the radial forging die surface includes the γ matrix with a homogeneous distribution of fine semi-spherical carbides. The weld structure consisted mostly of columnar dendrites with low grain boundaries. Also, microstructural investigation of the die surface during operation showed that the weld structure of the die surface has remained without any considerable change. Only dendrites were deformed and broken. Moreover, grain boundaries of the dendrites were revealed during service.

Medium carbon vanadium steels for closed die forging

International Nuclear Information System (INIS)

Jeszensky, Gabor; Plaut, Ronald Lesley

1993-01-01

This work analyses the medium carbon micro alloyed vanadium potential for closed die forged production. The steels reach the mechanical resistance requests during cooling after forging, eliminating the subsequent thermal treatment. Those steels also present good fatigue resistance and machinability. The industrial scale experiments are also reported

[A method of temperature measurement for hot forging with surface oxide based on infrared spectroscopy].

Science.gov (United States)

Zhang, Yu-cun; Qi, Yan-de; Fu, Xian-bin

2012-05-01

High temperature large forging is covered with a thick oxide during forging. It leads to a big measurement data error. In this paper, a method of measuring temperature based on infrared spectroscopy is presented. It can effectively eliminate the influence of surface oxide on the measurement of temperature. The method can measure the surface temperature and emissivity of the oxide directly using the infrared spectrum. The infrared spectrum is radiated from surface oxide of forging. Then it can derive the real temperature of hot forging covered with the oxide using the heat exchange equation. In order to greatly restrain interference spectroscopy through included in the received infrared radiation spectrum, three interference filter system was proposed, and a group of optimal gap parameter values using spectral simulation were obtained. The precision of temperature measurement was improved. The experimental results show that the method can accurately measure the surface temperature of high temperature forging covered with oxide. It meets the requirements of measurement accuracy, and the temperature measurement method is feasible according to the experiment result.

Gear hot forging process robust design based on finite element method

International Nuclear Information System (INIS)

Xuewen, Chen; Won, Jung Dong

2008-01-01

During the hot forging process, the shaping property and forging quality will fluctuate because of die wear, manufacturing tolerance, dimensional variation caused by temperature and the different friction conditions, etc. In order to control this variation in performance and to optimize the process parameters, a robust design method is proposed in this paper, based on the finite element method for the hot forging process. During the robust design process, the Taguchi method is the basic robust theory. The finite element analysis is incorporated in order to simulate the hot forging process. In addition, in order to calculate the objective function value, an orthogonal design method is selected to arrange experiments and collect sample points. The ANOVA method is employed to analyze the relationships of the design parameters and design objectives and to find the best parameters. Finally, a case study for the gear hot forging process is conducted. With the objective to reduce the forging force and its variation, the robust design mathematical model is established. The optimal design parameters obtained from this study indicate that the forging force has been reduced and its variation has been controlled

Optimum design of forging process parameters and preform shape under uncertainties

International Nuclear Information System (INIS)

Repalle, Jalaja; Grandhi, Ramana V.

2004-01-01

Forging is a highly complex non-linear process that is vulnerable to various uncertainties, such as variations in billet geometry, die temperature, material properties, workpiece and forging equipment positional errors and process parameters. A combination of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion and production risk. Identifying the sources of uncertainties, quantifying and controlling them will reduce risk in the manufacturing environment, which will minimize the overall cost of production. In this paper, various uncertainties that affect forging tool life and preform design are identified, and their cumulative effect on the forging process is evaluated. Since the forging process simulation is computationally intensive, the response surface approach is used to reduce time by establishing a relationship between the system performance and the critical process design parameters. Variability in system performance due to randomness in the parameters is computed by applying Monte Carlo Simulations (MCS) on generated Response Surface Models (RSM). Finally, a Robust Methodology is developed to optimize forging process parameters and preform shape. The developed method is demonstrated by applying it to an axisymmetric H-cross section disk forging to improve the product quality and robustness

Qualification of laser based additive production for manufacturing of forging Tools

Directory of Open Access Journals (Sweden)

Junker Daniel

2015-01-01

Full Text Available Mass customization leads to very short product life cycles, so the costs of a tool have to be amortized with a low number of workpieces. Especially for highly loaded tools, like those for forging, that leads to expensive products. Therefore more economical production processes for tool manufacturing have to be investigated. As laser additive manufacturing is already used for the production of moulds for injection moulding, this technology maybe could also improve the forging tool production. Within this paper laser metal deposition, which is industrially used for tool repair, will be investigated for the use in tool manufacturing. Therefore a mechanical characterization of parts built with different laser process parameters out of the hot work tool steel 1.2709 is made by upsetting tests and hardness measurements. So the influence of the additive manufacturing process on the hardness distribution is analysed.

Ultra-large size austenitic stainless steel forgings for fast breeder reactor 'Monju'

International Nuclear Information System (INIS)

Tsukada, Hisashi; Suzuki, Komei; Sato, Ikuo; Miura, Ritsu.

1988-01-01

The large SUS 304 austenitic stainless steel forgings for the reactor vessel of the prototype FBR 'Monju' of 280 MWe output were successfully manufactured. The reactor vessel contains the heart of the reactor and sodium coolant at 530 deg C, and its inside diameter is about 7 m, and height is about 18 m. It is composed of 12 large forgings, that is, very thick flanges and shalls made by ring forging and an end plate made by disk forging and hot forming, using a special press machine. The manufacture of these large forgings utilized the results of the basic test on the material properties in high temperature environment and the effect that the manufacturing factors exert on the material properties and the results of the development of manufacturing techniques for superlarge forgings. The problems were the manufacturing techniques for the large ingots of 250 t class of high purity, the hot working techniques for stainless steel of fine grain size, the forging techniques for superlarge rings and disks, and the machining techniques of high precision for particularly large diameter, thin wall rings. The manufacture of these large stainless steel forgings is reported. (Kako, I.)

Effect of Forging Parameters on Low Cycle Fatigue Behaviour of Al/Basalt Short Fiber Metal Matrix Composites

Directory of Open Access Journals (Sweden)

R. Karthigeyan

2013-01-01

Full Text Available This paper deals with metal matrix composites (MMCs of Al 7075 alloy containing different weight percentage (2.5, 5, 7.5, and 10 basalt short fiber reinforcement and unreinforced matrix alloy. The samples were produced by the permanent stir casting technique. The casting ingots were cut into blanks to be forged in single stage and double stage, using MN press and graphite-based lubricant. The microstructures and fatigue properties of the matrix alloy and MMC samples were investigated in the as cast state and in the single and double stage forging operations. The microstructure results showed that the forged sample had a uniform distribution of the basalt short fiber throughout the specimens. Evaluation of the fatigue properties showed that the forged samples had higher values than those of the as cast counterparts. After forging, the enhancement of the fatigue strength of the matrix alloy was so significant and high in the case of 2.5 and 5.0 wt. percentage basalt short fiber reinforced MMC, and there was no enhancement in 7.5 and 10 weight percentages short fiber reinforced MMCs. The fracture damage was mainly due to decohesion at the matrix-fiber interface.

Effect of forging parameters on low cycle fatigue behaviour of Al/basalt short fiber metal matrix composites.

Science.gov (United States)

Karthigeyan, R; Ranganath, G

2013-01-01

This paper deals with metal matrix composites (MMCs) of Al 7075 alloy containing different weight percentage (2.5, 5, 7.5, and 10) basalt short fiber reinforcement and unreinforced matrix alloy. The samples were produced by the permanent stir casting technique. The casting ingots were cut into blanks to be forged in single stage and double stage, using MN press and graphite-based lubricant. The microstructures and fatigue properties of the matrix alloy and MMC samples were investigated in the as cast state and in the single and double stage forging operations. The microstructure results showed that the forged sample had a uniform distribution of the basalt short fiber throughout the specimens. Evaluation of the fatigue properties showed that the forged samples had higher values than those of the as cast counterparts. After forging, the enhancement of the fatigue strength of the matrix alloy was so significant and high in the case of 2.5 and 5.0 wt. percentage basalt short fiber reinforced MMC, and there was no enhancement in 7.5 and 10 weight percentages short fiber reinforced MMCs. The fracture damage was mainly due to decohesion at the matrix-fiber interface.

Effect of raw materials and hardening process on hardness of manually forged knife

Science.gov (United States)

Balkhaya, Suwarno

2017-06-01

Knives are normally made by forging process either using a machine or traditional method by means of hammering process. This present work was conducted to study the effects of steel raw materials and hardening process on the hardness of manually forged knives. The knife samples were made by traditional hammering (forging) process done by local blacksmith. Afterward, the samples were heat treated with two different hardening procedures, the first was based on the blacksmith procedure and the second was systematically done at the laboratory. The forging was done in the temperature ranged between 900-950°C, while the final temperature ranged between 650-675°C. The results showed that knives made of spring steel and heat treated in simulated condition at the laboratory obtained higher level of hardness, i.e. 62 HRC. In general, knives heat treated by local blacksmith had lower level of hardness that those obtained from simulated condition. Therefore, we concluded that the traditional knife quality in term of hardness can be improved by optimizing the heat treatment schedule.

77 FR 14445 - Application for a License To Export Steel Forging

Science.gov (United States)

2012-03-09

... NUCLEAR REGULATORY COMMISSION Application for a License To Export Steel Forging Pursuant to 10 CFR 110.70(b) ``Public Notice of Receipt of an Application,'' please take notice that the Nuclear... head steel February 7, 2012 forging. forging will be XR175 machined into the 11005983 finished vessel...

Identification of Forged Bank of England 20 Gbp Banknotes Using IR Spectroscopy

Science.gov (United States)

Sonnex, Emily

2014-06-01

Bank of England notes of 20 GBP denomination have been studied using infrared spectroscopy in order to generate a method to identify forged notes. A principal aim of this work was to develop a method so that a small, compact ATR FTIR instrument could be used by bank workers, police departments or others such as shop assistants to identify forged notes in a non-lab setting. The ease of use of the instrument is the key to this method, as well as the relatively low cost. The presence of a peak at 1400 wn from the blank paper section of a forged note proved to be a successful indicator of the note's illegality for the notes that we studied. Moreover, differences between the spectra of forged and genuine 20 GBP notes were observed in the ν(OH) (ca. 3500 wn), ν(C-H) (ca. 2900 wn) and ν(C=O) (ca. 1750 wn) regions of the IR spectrum recorded for the polymer film covering the holographic strip. In cases where these simple tests fail, we have shown how an infrared microscope can be used to further differentiate genuine and forged banknotes by producing infrared maps of selected areas of the note contrasting inks with background paper. Further to this, with an announcement by the Bank of England to produce polymer banknotes in the future, the work has been extended using Australian polymer banknotes to show that the method would be transferable.

Development of Oxide Dispersion Strengthened (ODS) Ferritic Steel Through Powder Forging

Science.gov (United States)

Kumar, Deepak; Prakash, Ujjwal; Dabhade, Vikram V.; Laha, K.; Sakthivel, T.

2017-04-01

Oxide dispersion strengthened (ODS) ferritic steels are candidates for cladding tubes in fast breeder nuclear reactors. In this study, an 18%Cr ODS ferritic steel was prepared through powder forging route. Elemental powders with a nominal composition of Fe-18Cr-2 W-0.2Ti (composition in wt.%) with 0 and 0.35% yttria were prepared by mechanical alloying in a Simoloyer attritor under argon atmosphere. The alloyed powders were heated in a mild steel can to 1473 K under flowing hydrogen atmosphere. The can was then hot forged. Steps of sealing, degassing and evacuation are eliminated by using powder forging. Heating ODS powder in hydrogen atmosphere ensures good bonding between alloy powders. A dense ODS alloy with an attractive combination of strength and ductility was obtained after re-forging. On testing at 973 K, a loss in ductility was observed in yttria-containing alloy. The strength and ductility increased with increase in strain rate at 973 K. Reasons for this are discussed. The ODS alloy exhibited a recrystallized microstructure which is difficult to achieve by extrusion. No prior particle boundaries were observed after forging. The forged compacts exhibited isotropic mechanical properties. It is suggested that powder forging may offer several advantages over the traditional extrusion/HIP routes for fabrication of ODS alloys.

Qualitative Research of AZ31 Magnesium Alloy Aircraft Brackets Produced by a New Forging Method

Directory of Open Access Journals (Sweden)

Dziubińska A.

2016-06-01

Full Text Available The paper reports a selection of numerical and experimental results of a new closed-die forging method for producing AZ31 magnesium alloy aircraft brackets with one rib. The numerical modelling of the new forming process was performed by the finite element method.The distributions of stresses, strains, temperature and forces were examined. The numerical results confirmed that the forgings produced by the new forming method are correct. For this reason, the new forming process was verified experimentally. The experimental results showed good agreement with the numerical results. The produced forgings of AZ31 magnesium alloy aircraft brackets with one rib were then subjected to qualitative tests.

Study on Manufacturing Process of Hollow Main Shaft by Open Die Forging

International Nuclear Information System (INIS)

Kwon, Yong Chul; Kang, Jong Hun; Kim, Sang Sik

2016-01-01

The main shaft is one of the key components connecting the rotor hub and gear box of a wind power generator. Typically, main shafts are manufactured by open die forging method. However, the main shaft for large MW class wind generators is designed to be hollow in order to reduce the weight. Additionally, the main shafts are manufactured by a casting process. This study aims to develop a manufacturing process for hollow main shafts by the open die forging method. The design of a forging process for a solid main shaft and hollow shaft was prepared by an open die forging process design scheme. Finite element analyses were performed to obtain the flow stress by a hot compression test at different temperature and strain rates. The control parameters of each forging process, such as temperature and effective strain, were obtained and compared to predict the suitability of the hollow main shaft forging process. Finally, high productivity reflecting material utilization ratio, internal quality, shape, and dimension was verified by the prototypes manufactured by the proposed forging process for hollow main shafts

Study on Manufacturing Process of Hollow Main Shaft by Open Die Forging

Energy Technology Data Exchange (ETDEWEB)

Kwon, Yong Chul [Gyeongnam Technopark, Changwon (Korea, Republic of); Kang, Jong Hun [Jungwon Univ., Goisan (Korea, Republic of); Kim, Sang Sik [Gyeongsang Natiional Univ., Jinju (Korea, Republic of)

2016-02-15

The main shaft is one of the key components connecting the rotor hub and gear box of a wind power generator. Typically, main shafts are manufactured by open die forging method. However, the main shaft for large MW class wind generators is designed to be hollow in order to reduce the weight. Additionally, the main shafts are manufactured by a casting process. This study aims to develop a manufacturing process for hollow main shafts by the open die forging method. The design of a forging process for a solid main shaft and hollow shaft was prepared by an open die forging process design scheme. Finite element analyses were performed to obtain the flow stress by a hot compression test at different temperature and strain rates. The control parameters of each forging process, such as temperature and effective strain, were obtained and compared to predict the suitability of the hollow main shaft forging process. Finally, high productivity reflecting material utilization ratio, internal quality, shape, and dimension was verified by the prototypes manufactured by the proposed forging process for hollow main shafts.

Optimising mechanical properties of hot forged nickel superalloy 625 components

Science.gov (United States)

Singo, Nthambe; Coles, John; Rosochowska, Malgorzata; Lalvani, Himanshu; Hernandez, Jose; Ion, William

2018-05-01

Hot forging and subsequent heat treatment were resulting in substandard mechanical properties of nickel superalloy, Alloy 625, components. The low strength was found to be due to inadequate deformation during forging, excessive grain growth and precipitation of carbides during subsequent heat treatment. Experimentation in a drop forging company and heat treatment facility led to the establishment of optimal parameters to minimise grain size and mitigate the adverse effects of carbide precipitation, leading to successful fulfilment of mechanical property specifications. This was achieved by reducing the number of operations, maximising the extent of deformation by changing the slug dimensions and its orientation in the die, and minimising the time of exposure to elevated temperatures in both the forging and subsequent heat treatment processes to avoid grain growth.

The effect of strain distribution on microstructural developments during forging in a newly developed nickel base superalloy

Energy Technology Data Exchange (ETDEWEB)

Buckingham, R.C. [Institute of Structural Materials, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN (United Kingdom); Argyrakis, C.; Hardy, M.C. [Rolls-Royce plc, PO Box 31, Derby DE24 8BJ (United Kingdom); Birosca, S., E-mail: 522042@swansea.ac.uk [Institute of Structural Materials, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN (United Kingdom)

2016-01-27

In the current study, the effect of strain distribution in a simple forging geometry on the propensity for recrystallization, and its impact on mechanical properties has been investigated in a newly developed experimental nickel-based superalloy. The new alloy was produced via a Powder Metallurgy (PM) route and was subsequently Hot Isostatic Processed (HIP), isothermally forged, and heat treated to produce a coarse grain microstructure with average grain size of 23–32 μm. The alloy was examined by means of Electron Back-Scatter Diffraction (EBSD) to characterise the microstructural features such as grain orientation and morphology, grain boundary characteristics and the identification of potential Prior Particle Boundaries (PPBs) throughout each stage of the processing route. Results at the central region of the cross-section plane parallel to the loading direction showed significant microstructural differences across the forging depth. This microstructural variation was found to be highly dependent on the value of local strain imparted during forging such that areas of low effective strain showed partial recrystallisation and a necklace grain structure was observed following heat treatment. Meanwhile, a fully recrystallised microstructure with no PPBs was observed in the areas of high strain values, in the central region of the forging.

Weld-forged rotors of the turbines for nuclear and thermal power plants

International Nuclear Information System (INIS)

Rudkovskij, A.F.; German, S.I.

1979-01-01

Considered is a principally new technology and equipment for assembling and welding superheavy rotors with mass up to 200 tons. Construction peculiarities and advantages of the application of weld-forged rotors are noted. The technology proposed permits to provide for a horizontal assembling, subsequent welding and quality control of rotors, one bench being used instead of three ones. The application of horizontal assembling and complex welding of rotors in one position permits not only to shorten the cycle of assembling and welding, too decrease the equipment costs and release production capacities, but also to improve substantially the quality of welds and especially the accuracy of rotor production. The equipment allows one to assemble and weld rotors with the mass up to 250 tons at maximum rotor diameter up to 2500 mm and length up to 13000 mm. Presented are data characterizing chemical composition and mechanical properties of steels used for forging of welded rotors. Also given are the results of studying mechanical properties of welded joints, welding and thermal treatment of which were made in accordance with the technology proposed. Serial production of rotors for turbines with the power of 500, 1000 and 1200 Mw is shown to be mastered along with the manufacture of welded rotors for cylinders of low, medium and high pressure turbines

Numerical simulation of the dynamic recrystallization behaviour in hot precision forging helical gears

Directory of Open Access Journals (Sweden)

Feng Wei

2015-01-01

Full Text Available In hot precision forging helical gears, the dynamic recrystallization phenomena will occur, which affect the microstructure of the formed part and in turn decide their mechanical properties. To investigate the effect of deformation temperature on the dynamic recrystallization in hot precision forging helical gears, a three dimensional (3D finite element (FE model was created by coupling the thermo-mechanical model with the microstructure evolution model developed based on the hot compressive experimental data of 20CrMnTiH steel. The hot precision forging process was simulated and the effect laws of the deformation temperature on the microstructure evolution the formed part were investigated. The results show that the dynamic recrystallization volume fraction and the average grain sizes increased with the increasing deformation temperature and the higher deformation temperature is beneficial to dynamic recrystallization and grain refinement.

Near net shape forging of titanium alloy turbine blade

International Nuclear Information System (INIS)

Morita, Akiyasu; Hattori, Shigeo; Tani, Kazuhito; Takemura, Atsushi; Ashida, Yoshio

1991-01-01

The isothermal forging process has been developed to produce turbine blades made of near β Ti-alloy Ti-10V-2Fe-3Al. It is important to set the preform at the optimum position of the die in order to get a high precision product. The deformation analysis by using FEM is effective to determine the optimum position. And also it is necessary to avoid buckling induced by the restriction of axial elongation of the material. As a result, Ti-10V-2Fe-3Al blades could be formed precisely by using only one stage of forging, and machining was needed only at the root. The thickness of the oxide layer induced on the surface of the forged blade was only 70μm. The mechanical properties of Ti-10V-2Fe-3Al blades after forging and annealing were superior to those of Ti-6Al-4V blades and were nearly uniform across the length of the blades. (author)

Forge, Arquillian, Swarm and Spring Boot: All play and no effort makes Simon a productive boy

CERN Multimedia

CERN. Geneva

2017-01-01

During this live coding session, Simon will shine some light on a range productivity tools that make software development a pleasure rather than a chore. Simon will live code 2 applications; a Java EE application, with JBoss Forge which uses JPA, Bean Validation, REST and Angular. We’ll test this application using Arquillian from within JBoss Forge. We’ll also show how a Java EE microservice can be developed in Forge and run using JBoss Swarm. The second application will be developed on Spring Boot and using JRebel we’ll rapidly develop and run a Spring application. Attendees will learn how to write code productively using tools designed for developers.

Plane strain forging of a niobium micro-alloyed steel

International Nuclear Information System (INIS)

Balancin, O.; Ferran L, G.; Rio de Janeiro Univ.

1984-01-01

Various termomechanical treatments were carried out on a niobium micro-alloyed steel and a low carbon steel as reference material, using an apparatus for hot phane strain forging. Control of processing variables and the presence of niobium strongly modify the austenite microstructure, which upon decomposition produces various phases such as polygonal and acicular ferrite and martensite, alone or together in variable proportions. Corresponding to this diversity of structures there is a wide variation in mechanical properties at room temperature: the initial yield point varies from 310 to 650 MPa and the reduction of area in uniaxial tension from 82 to 57% for the niobium steel. These results show that hot forging a niobium micro-alloyed steel may be a suitable manufacturing process for satisfying a wide range of specifications in a final product with low equivalent carbon. (Author) [pt

Evolution of A-Type Macrosegregation in Large Size Steel Ingot After Multistep Forging and Heat Treatment

Science.gov (United States)

Loucif, Abdelhalim; Ben Fredj, Emna; Harris, Nathan; Shahriari, Davood; Jahazi, Mohammad; Lapierre-Boire, Louis-Philippe

2018-06-01

A-type macrosegregation refers to the channel chemical heterogeneities that can be formed during solidification in large size steel ingots. In this research, a combination of experiment and simulation was used to study the influence of open die forging parameters on the evolution of A-type macrosegregation patterns during a multistep forging of a 40 metric ton (MT) cast, high-strength steel ingot. Macrosegregation patterns were determined experimentally by macroetch along the longitudinal axis of the forged and heat-treated ingot. Mass spectroscopy, on more than 900 samples, was used to determine the chemical composition map of the entire longitudinal sectioned surface. FORGE NxT 1.1 finite element modeling code was used to predict the effect of forging sequences on the morphology evolution of A-type macrosegregation patterns. For this purpose, grain flow variables were defined and implemented in a large scale finite element modeling code to describe oriented grains and A-type segregation patterns. Examination of the A-type macrosegregation showed four to five parallel continuous channels located nearly symmetrical to the axis of the forged ingot. In some regions, the A-type patterns became curved or obtained a wavy form in contrast to their straight shape in the as-cast state. Mass spectrometry analysis of the main alloying elements (C, Mn, Ni, Cr, Mo, Cu, P, and S) revealed that carbon, manganese, and chromium were the most segregated alloying elements in A-type macrosegregation patterns. The observed differences were analyzed using thermodynamic calculations, which indicated that changes in the chemical composition of the liquid metal can affect the primary solidification mode and the segregation intensity of the alloying elements. Finite element modeling simulation results showed very good agreement with the experimental observations, thereby allowing for the quantification of the influence of temperature and deformation on the evolution of the shape of the

2016 Accomplishments. Tritium aging studies on stainless steel. Forging process effects on the fracture toughness properties of tritium-precharged stainless steel

Energy Technology Data Exchange (ETDEWEB)

Morgan, Michael J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-01-01

Forged austenitic stainless steels are used as the materials of construction for pressure vessels designed to contain tritium at high pressure. These steels are highly resistant to tritium-assisted fracture but their resistance can depend on the details of the forging microstructure. During FY16, the effects of forging strain rate and deformation temperature on the fracture toughness properties of tritium-exposed-and-aged Type 304L stainless steel were studied. Forgings were produced from a single heat of steel using four types of production forging equipment – hydraulic press, mechanical press, screw press, and high-energy-rate forging (HERF). Each machine imparted a different nominal strain rate during the deformation. The objective of the study was to characterize the J-Integral fracture toughness properties as a function of the industrial strain rate and temperature. The second objective was to measure the effects of tritium and decay helium on toughness. Tritium and decay helium effects were measured by thermally precharging the as-forged specimens with tritium gas at 34.5 MPa and 350°C and aging for up to five years at -80°C to build-in decay helium prior to testing. The results of this study show that the fracture toughness properties of the as-forged steels vary with forging strain rate and forging temperature. The effect is largely due to yield strength as the higher-strength forgings had the lower toughness values. For non-charged specimens, fracture toughness properties were improved by forging at 871°C versus 816°C and Screw-Press forgings tended to have lower fracture toughness values than the other forgings. Tritium exposures reduced the fracture toughness values remarkably to fracture toughness values averaging 10-20% of as-forged values. However, forging strain rate and temperature had little or no effect on the fracture toughness after tritium precharging and aging. The result was confirmed by fractography which indicated that fracture modes

Production of A356 aluminum alloy wheels by thixo-forging combined with a low superheat casting process

Directory of Open Access Journals (Sweden)

Wang Shuncheng

2013-09-01

Full Text Available The A356 aluminum alloy wheels were produced by thixo-forging combined with a low superheat casting process. The as-cast microstructure, microstructure evolution during reheating and the mechanical properties of thixo-forged wheels made from the A356 aluminum alloy were studied. The results show that the A356 aluminum alloy round billet with fine, uniform and non-dendritic grains can be obtained when the melt is cast at 635 篊. When the round billet is reheated at 600 篊 for 60 min, the non-dendritic grains are changed into spherical ones and the round billet can be easily thixo-forged into wheels. The tensile strength, yield strength and elongation of the thixo-forged wheels with T6 heat treatment are 327.6 MPa, 228.3 MPa and 7.8%, respectively, which are higher than those of a cast wheel. It is suggested that the thixo-forging combined with the low superheat casting process is an effective technique to produce aluminum alloy wheels with high mechanical properties.

Geologic setting of the proposed Fallon FORGE Site, Nevada: Suitability for EGS research and development

Science.gov (United States)

Faulds, James E.; Blankenship, Douglas; Hinz, Nicholas H.; Sabin, Andrew; Nordquist, Josh; Hickman, Stephen H.; Glen, Jonathan; Kennedy, Mack; Siler, Drew; Robinson-Tait, Ann; Williams, Colin F.; Drakos, Peter; Calvin, Wendy M.

2015-01-01

entire Fallon project. The well data indicate that a sizeable area (~4.5 km2 ) has adequate temperatures in crystalline basement but lacks sufficient permeability within the proposed FORGE site. There are two possible, competent target formations in Mesozoic basement for stimulation in the FORGE project area: 1) Jurassic felsic metavolcanic rocks/and or metaquartzite; and 2) Cretaceous granitic intrusions. These units make up at least 3 km3 in the project area and have target temperatures of ~175-215o C. The abundant well data and detailed geophysical surveys (e.g., gravity, MT, and seismic reflection) provide significant subsurface control for the site and will permit development of a detailed 3D model. The documented temperatures, low permeability, and basement lithologies, as well as abundant available data facilitate development of a site dedicated to testing and improving new EGS technologies and techniques, thus making Fallon an ideal candidate for FORGE.

Studies of the quality and cost-effectiveness of a novel conceptof open-die forged powerplant main shaft

Directory of Open Access Journals (Sweden)

P. Skubisz

2015-04-01

Full Text Available An innovatory concept of open-die forging of windmill main shaft is described. Comparative study of the new technology based on the concept of cogging hollow shaft on mandrel featuring material savings and higher quality of a finished part versus traditional production chain of this component is presented, indicating benefits and technological setbacks of industrial implementation. Results of industrial sampling aided with numerical simulation form guidelines for technological realization.

X-ray tomography studies on porosity and particle size distribution in cast in-situ Al-Cu-TiB{sub 2} semi-solid forged composites

Energy Technology Data Exchange (ETDEWEB)

Mathew, James; Mandal, Animesh [School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar (India); Warnett, Jason; Williams, Mark A. [WMG, University of Warwick, Coventry CV4 7AL (United Kingdom); Chakraborty, Madhusudan [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur (India); Srirangam, Prakash, E-mail: p.srirangam@warwick.ac.uk [WMG, University of Warwick, Coventry CV4 7AL (United Kingdom)

2016-08-15

X-ray computed tomography (XCT) was used to characterise the internal microstructure and clustering behaviour of TiB{sub 2} particles in in-situ processed Al-Cu metal matrix composites prepared by casting method. Forging was used in semi-solid state to reduce the porosity and to uniformly disperse TiB{sub 2} particles in the composite. Quantification of porosity and clustering of TiB{sub 2} particles was evaluated for different forging reductions (30% and 50% reductions) and compared with an as-cast sample using XCT. Results show that the porosity content was decreased by about 40% due to semi-solid forging as compared to the as-cast condition. Further, XCT results show that the 30% forging reduction resulted in greater uniformity in distribution of TiB{sub 2} particles within the composite compared to as-cast and the 50% forge reduction in semi-solid state. These results show that the application of forging in semi-solid state enhances particle distribution and reduces porosity formation in cast in-situ Al-Cu-TiB{sub 2} metal matrix composites. - Highlights: •XCT was used to visualise 3D internal structure of Al-Cu-TiB{sub 2} MMCs. •Al-Cu-TiB{sub 2} MMC was prepared by casting using flux assisted synthesis method. •TiB{sub 2} particles and porosity size distribution were evaluated. •Results show that forging in semi-solid condition decreases the porosity content and improve the particle dispersion in MMCs.

Development of a forging technology for the production of high-pressure compressor blades from γ-titanium aluminide. Project C: production of primary wrought material for the forging of turbine blades from gamma-TiAl and their microstructural optimization. Final report

International Nuclear Information System (INIS)

Appel, F.; Oehring, M.; Lorenz, U.; Wagner, R.

1999-01-01

By the development of a new canning technique which resulted in an effective thermal isolation of can and billet the flow stress mismatch of can and billet material could be minimized, which allowed crack-free and uniform extrusion. Using this technique which has been applied for patent hot extrusion is an effective and matured working method for ingot material. It allows to produce fine-grained and almost fully recrystallized material with increased workability as has been found by the determination of the forging window as well as by the successful forging of more than 200 compressor blades by the project partner Thyssen Umformtechnik. By forging under suited conditions also a microstructural homogenization is achieved in comparison to extruded material. (orig.)

Shape optimization of metal forming and forging products using the stress equivalent static loads calculated from a virtual model

International Nuclear Information System (INIS)

Jang, Hwan Hak; Jeong, Seong Beom; Park, Gyung Jin

2012-01-01

A shape optimization is proposed to obtain the desired final shape of forming and forging products in the manufacturing process. The final shape of a forming product depends on the shape parameters of the initial blank shape. The final shape of a forging product depends on the shape parameters of the billet shape. Shape optimization can be used to determine the shape of the blank and billet to obtain the appropriate final forming and forging products. The equivalent static loads method for non linear static response structural optimization (ESLSO) is used to perform metal forming and forging optimization since nonlinear dynamic analysis is required. Stress equivalent static loads (stress ESLs) are newly defined using a virtual model by redefining the value of the material properties. The examples in this paper show that optimization using the stress ESLs is quite useful and the final shapes of a forming and forging products are identical to the desired shapes

Friction and wear in hot forging of steels

International Nuclear Information System (INIS)

Daouben, E.; Dubar, L.; Dubar, M.; Deltombe, R.; Dubois, A.; Truong-Dinh, N.; Lazzarotto, L.

2007-01-01

In the field of hot forging of steels, the mastering of wear phenomena enables to save cost production, especially concerning tools. Surfaces of tools are protected thanks to graphite. The existing lubrication processes are not very well known: amount and quality of lubricant, lubrication techniques have to be strongly optimized to delay wear phenomena occurrence. This optimization is linked with hot forging processes, the lubricant layers must be tested according to representative friction conditions. This paper presents the first part of a global study focused on wear phenomena encountered in hot forging of steels. The goal is the identification of reliable parameters, in order to bring knowledge and models of wear. A prototype testing stand developed in the authors' laboratory is involved in this experimental analysis. This test is called Warm and Hot Upsetting Sliding Test (WHUST). The stand is composed of a heating induction system and a servo-hydraulic system. Workpieces taken from production can be heated until 1200 deg. C. A nitrided contactor representing the tool is heated at 200 deg. C. The contactor is then coated with graphite and rubs against the workpiece, leaving a residual track on it. Friction coefficient and surface parameters on the contactor and the workpiece are the most representative test results. The surface parameters are mainly the sliding length before defects occurrence, and the amplitude of surface profile of the contactor. The developed methodology will be first presented followed by the different parts of the experimental prototype. The results of experiment show clearly different levels of performance according to different lubricants

Developments of New Lubricants for Cold Forging of Stainless Steel

DEFF Research Database (Denmark)

Steenberg, Thomas; Christensen, Erik; Olesen, P.

1997-01-01

Two new lubricant systems for cold forging of stainless steel have been developed. The main component of these systems are FeCl3 and ZnCa2(PO4)2, respectively. Both lubricant systems have been tested using a backward extrusion test. The results show excellent lubricating properties with respect...

Application of CAD/CAE/CAM in forging process: a review

International Nuclear Information System (INIS)

Ahmad Baharuddin Abdullah; Hamouda, A.M.S.

2005-01-01

Forging can be described as the process in which metal is plastically deformed with application of huge pressure. The process not only changes the shape but also improves the properties of the forged parts due to grain size refinement. Conventionally, the empirical trial and error method has been applied, but recently there are various tools are employed to improved product quality and economic of the process. For example, Computer Aided Design (CAD) is widely used in modeling of the process, while Computer Aided Engineering (CAE) tools have been utilized in analyzing the process. To physically demonstrate the process, Computer Aided Manufacturing (CAM) such as CNC machine has been exploited. In order to improve forging process efficiency, an integrated system that combines all advantages of CAD, CAM and CAE need to be developed. This paper presents an overview of computer aided simulation such as CAD, CAE and CAM application in forging process. (Author)

Calculation of recovery plasticity in multistage hot forging under isothermal conditions.

Science.gov (United States)

Zhbankov, Iaroslav G; Perig, Alexander V; Aliieva, Leila I

2016-01-01

A widely used method for hot forming steels and alloys, especially heavy forging, is the process of multistage forging with pauses between stages. The well-known effect which accompanies multistage hot forging is metal plasticity recovery in comparison with monotonic deformation. A method which takes into consideration the recovery of plasticity in pauses between hot deformations of a billet under isothermal conditions is proposed. This method allows the prediction of billet forming limits as a function of deformation during the forging stage and the duration of the pause between the stages. This method takes into account the duration of pauses between deformations and the magnitude of subdivided deformations. A hot isothermal upsetting process with pauses was calculated by the proposed method. Results of the calculations have been confirmed with experimental data.

Finite element simulations and experimental investigations on ductile fracture in cold forging of aluminum alloy

Science.gov (United States)

Amiri, Amir; Nikpour, Amin; Saraeian, Payam

2018-05-01

Forging is one of the manufacturing processes of aluminium parts which has two major categories: called hot and cold forging. In the cold forging, the dimensional and geometrical accuracy of final part is high. However, fracture may occur in some aluminium alloys during the process because of less workability. Fracture in cold forging can be in the form of ductile, brittle or combination of both depending on the alloy type. There are several criteria for predicting fracture in cold forging. In this study, cold forging process of 6063 aluminium alloy for three different parts is simulated in order to predict fracture. The results of numerical simulations of Freudenthal criterion is in conformity with experimental tests.

Influence of performance improvement of AP1000 nuclear island main equipment forging on manufacturing

International Nuclear Information System (INIS)

Liu Zhiying

2013-01-01

In order to comply with the 60-year design life of an AP1000 nuclear power station, higher strength and ductility requirements have been made on AP1000 nuclear island SG forgings than on CPR1000 nuclear island main equipment. In addition, bigger size of AP1000 nuclear island SG forgings increases the difficulty of manufacturing them. Insufficient recognition of these changes may cause unstable quality of forgings and possible quality problems in follow-up welding procedure. On the basis of comparison and analysis of AP1000 nuclear island SG forgings and CPR1000 nuclear island forgings, this thesis suggests clear directions for the actions we need to take. (author)

Numerical simulation and experimental verification of microstructure evolution in large forged pipe used for AP1000 nuclear power plants

International Nuclear Information System (INIS)

Wang, Shenglong; Yang, Bin; Zhang, Mingxian; Wu, Huanchun; Peng, Jintao; Gao, Yang

2016-01-01

Highlights: • Establish systematically the database of 316LN stainless steel for Deform-3D. • Simulate the microstructure evolution during forging of AP1000 primary coolant pipe. • Carry out full-scale forging experiment for verification in engineering practice. • Get desirable grain size in simulation and experiment. • The variation trends of grain sizes in simulation and experiment are consistent. - Abstract: AP1000 primary coolant pipe is a large special-shaped forged pipe made of 316LN stainless steel. Due to the non-uniform temperature and deformation during its forging, coarse and fine grains usually coexist in the forged pipe, resulting in the heterogeneous microstructure and anisotropic performance. To investigate the microstructure evolution during the entire forging process, in the present research, the database of the 316LN stainless steel was established and a numerical simulation was performed. The results indicate that the middle body section of the forged pipe has an extremely uniform average grain size with the value smaller than 30 μm. The grain sizes in the ends of body sections were ranged from 30 μm to 60 μm. Boss sections have relatively homogeneous microstructure with the average grain size 30 μm to 44 μm. Furthermore, a full-scale hot forging was carried out for verification. Comparison of theoretical and experimental results showed good agreement and hence demonstrated the capabilities of the numerical simulation presented here. It is noteworthy that all grains in the workpiece were confirmed less than 180 μm, which meets the designer’s demands.

Simulation and analysis of hot forging process for industrial locking gear elevators

Science.gov (United States)

Maarefdoust, M.; Kadkhodayan, M.

2010-06-01

In this paper hot forging process for industrial locking gear elevators is simulated and analyzed. An increase in demand of industrial locking gear elevators with better quality and lower price caused the machining process to be replaced by hot forging process. Production of industrial locking gear elevators by means of hot forging process is affected by many parameters such as billet temperature, geometry of die and geometry of pre-formatted billet. In this study the influences of billet temperature on effective plastic strain, radius of die corners on internal stress of billet and thickness of flash on required force of press are investigated by means of computer simulation. Three-dimensional modeling of initial material and die are performed by Solid Edge, while simulation and analysis of forging are performed by Super Forge. Based on the computer simulation the required dies are designed and the workpieces are formed. Comparison of simulation results with experimental data demonstrates great compatibility.

75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

Science.gov (United States)

2010-11-18

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,376] Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood Forge Division; Currently Known As Contech Forgings, LLC..., applicable to workers of Kaiser Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division...

Numerical modeling of axi-symmetrical cold forging process by ``Pseudo Inverse Approach''

Science.gov (United States)

Halouani, A.; Li, Y. M.; Abbes, B.; Guo, Y. Q.

2011-05-01

The incremental approach is widely used for the forging process modeling, it gives good strain and stress estimation, but it is time consuming. A fast Inverse Approach (IA) has been developed for the axi-symmetric cold forging modeling [1-2]. This approach exploits maximum the knowledge of the final part's shape and the assumptions of proportional loading and simplified tool actions make the IA simulation very fast. The IA is proved very useful for the tool design and optimization because of its rapidity and good strain estimation. However, the assumptions mentioned above cannot provide good stress estimation because of neglecting the loading history. A new approach called "Pseudo Inverse Approach" (PIA) was proposed by Batoz, Guo et al.. [3] for the sheet forming modeling, which keeps the IA's advantages but gives good stress estimation by taking into consideration the loading history. Our aim is to adapt the PIA for the cold forging modeling in this paper. The main developments in PIA are resumed as follows: A few intermediate configurations are generated for the given tools' positions to consider the deformation history; the strain increment is calculated by the inverse method between the previous and actual configurations. An incremental algorithm of the plastic integration is used in PIA instead of the total constitutive law used in the IA. An example is used to show the effectiveness and limitations of the PIA for the cold forging process modeling.

Numerical modelling of damage evolution in ingot forging

DEFF Research Database (Denmark)

Christiansen, Peter; Martins, Paulo A.F.; Bay, Niels Oluf

2015-01-01

The ingot forging process is numerically simulated applying both the Shima-Oyane porous plasticity model as a coupled damage model and the uncoupled normalized Cockcroft & Latham criterion. Four different cases including two different lower die angles (120º and 180º) and two different sizes of feed...... (400mm and 800mm) are analysed. Comparison of the simulation results with recommendations in literature on ingot forging, indicates the normalized Cockcroft & Latham damage criterion to be the most realistic of the two....

Investigation of the influence of hybrid layers on the life time of hot forging dies

Directory of Open Access Journals (Sweden)

S. Legutko

2013-04-01

Full Text Available The paper deals with the issues related in the process of drop forging with special attention paid to the durability of forging tools. It presents the results of industrial investigation of the influence of hybrid layers on hot forging dies. The effectiveness of hybrid layers type nitrided layer/PVD coating applied for extending the life of forging tools whose working surfaces are exposed to such complex exploitation conditions as, among others, cyclically varying high thermal and mechanical loads, as well as intensive abrasion at raised temperature. The examination has been performed on a set of forging tools made of Unimax steel and intended for forging steel rings of gear box synchronizer in the factory FAS in Swarzedz (Poland.

Microstructure evolution and mechanical properties of a particulate reinforced magnesium matrix composites forged at elevated temperatures

International Nuclear Information System (INIS)

Deng, K.K.; Wu, K.; Wang, X.J.; Wu, Y.W.; Hu, X.S.; Zheng, M.Y.; Gan, W.M.; Brokmeier, H.G.

2010-01-01

SiCp/AZ91 magnesium matrix composite was fabricated by stir casting. The as-cast ingots were cut into cylindrical billets, and then forged at different temperatures (320, 370, 420, 470 and 520 deg. C) at a constant RAM speed of 15 mm/s with 50% reduction. The microstructure evolution of the composites during forging was investigated by optical microscope, scanning electron microscope, and transmission electron microscope. The texture of the forged composites was measured by neutron diffraction. Mechanical properties of the composite at different forging temperatures were tested by tensile tests at room temperature. It was found that a strong basal plane texture formed during forging, and the intensity of basal plane texture weakened as forging temperatures increased. The particle distribution in the composite was significantly improved by hot forging. Typical microstructures were obtained after forging at different temperatures and the composite with different microstructures offered different mechanical properties during tensile test.

Analysis of Filling and Stresses in the Hot Forging Process Depending on Flange Die Shapes

International Nuclear Information System (INIS)

Kim, Jun Hyoung; Kim, Cheol

2010-01-01

Hot closed-forging process and the die used for forming an automotive flange were analyzed from the viewpoints of heat transfer, grain-flow lines, and stresses to obtain a forged product without defects such as surface cracks, laps, cold shots, and partial filling. The forging process including up-set, pre-forging, final forging and pressing forces was investigated using finite element analysis. The influence of the preform die and the ratio of the heights of the upper die to lower die on the forging process and die were investigated and a die shape (10 .deg. for the preform die, and 1.5:1 ratio for the final die) suitable to achieve successful forging was determined on the basis of a parametric study. All parametric design requirements such as strength, full filling, and a load limit of 13,000 KN were satisfied for this newly developed flange die. New dies and flanges were fabricated and investigated. Defects such as partial filling and surface cracks were not observed

76 FR 66996 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Forging...

Science.gov (United States)

2011-10-28

... for OMB Review; Comment Request; Forging Machines ACTION: Notice. SUMMARY: The Department of Labor... collection request (ICR) titled, ``Forging Machines,'' to the Office of Management and Budget (OMB) for....218, it is mandatory for covered employers to conduct and to document periodic inspections of forging...

The effects of thermomechanical history on the microstructure of a nickel-base superalloy during forging

Energy Technology Data Exchange (ETDEWEB)

Gardner, S., E-mail: 485354@swansea.ac.uk [College of Engineering, Bay Campus, Swansea University, Swansea SA1 8EN (United Kingdom); Li, W. [Rolls-Royce plc, PO Box 31, Derby DE24 8BJ (United Kingdom); Coleman, M. [College of Engineering, Bay Campus, Swansea University, Swansea SA1 8EN (United Kingdom); Johnston, R., E-mail: r.johnston@swansea.ac.uk [College of Engineering, Bay Campus, Swansea University, Swansea SA1 8EN (United Kingdom)

2016-06-21

The effect of thermo-mechanical history on hot compression behaviour and resulting microstructures of a nickel base superalloy is presented. Hot compression tests were carried out on HAYNES® 282® specimens to varying strains from 0.1 to 0.8. Both single pass and multi-pass tests were completed. 60 min inter-pass times were utilized to accurately replicate industrial forging practices. The effect of dynamic, metadynamic and static recrystallization during inter-pass times on flow stress was investigated. The resulting microstructures were analysed using scanning electron, optical microscopy and EBSD to relate grain size and homogeneity with flow stress data. The study showed a negligible difference between multi-pass and single pass tests for strain increments above 0.2. Therefore, when modelling similar low strain and strain rate forging processes in HAYNES® 282®, previous forging steps can be ignored.

The analysis of forming and strain state of the hollow step forgings during the enlarging process

Directory of Open Access Journals (Sweden)

Олег Євгенійович Марков

2017-12-01

Full Text Available Improving safety, accelerating construction and extending the life of nuclear power plants is one of the main directions of the development of the energy industry. From this point of view, much attention is being paid to the production of forgings, which combine a few details today. This requires the use of new technologies with the use of non-standard tools. The purpose of the work is analyze of the shape and the deformation state of the conical stepped forging when rolling the stepped workpiece with the simultaneous deformation of the protuberance and the ledge. The simulation was performed using finite element method, which is consistent with experimental data. Experimental studies were carried out on lead models. Rolling of stepped workpiece with simultaneous deformation of the protrusion and ledge leads to the appearance of conical forging. Taper on the side of the ledge occurs at the initial stage of rolling and during the whole process increases. The emergence of a conical shape is explained by the fact that during slipping, with the same absolute deformation (stroke, the ledge gets more accumulated deformation through a more precise wall.

Analysis of hot rolling and hot forging effects on mechanical properties and microstructure of ZrNbMoGe alloy

International Nuclear Information System (INIS)

AH Ismoyo; Parikin; Bandriyana

2014-01-01

Research on formation technique by a combined method of rolling and forging has been carried out in order to improve the mechanical properties of ZrNbMoGe alloy to be used as fuel cladding in NPP (Nuclear Power Plant) application. The effects of rolling and forging were analyzed several tests. The tests were conducted for zirconium alloy specimen with a composition of (in % wt.) 97% Zr, 0,5% Mo, 2% Nb and 0,5% Ge, where the specimen was melted with an arc-furnace. The hot rolling and forging were conducted at 900 °C and 950 °C respectively. Hardness test was carried out by using a microhardness testing machine, while microstructure examination and crystal structure analysis were conducted with an optical microscope and an X-ray diffractometer. The results show that the hardness of the alloy increase from 141.21 HV (starting material) to 210.47 HV (hot rolled material) and 365.75 HV (hot forged material). Texturing phenomenon is clearly figured on the microstructure due to hot rolling and forging process. Analysis by diffractogram also indicates that the hot rolling and forging process has influence on the crystal orientation of dominant preferred direction in the reflection plane of (10ī1), recorded from the rise of intensity counting from about 2500 to 3000. In summary, hot forging and rolling process can change the mechanical properties (hardness and texture) and microstructure of materials. (author)

Optimization of the Hot Forging Processing Parameters for Powder Metallurgy Fe-Cu-C Connecting Rods Based on Finite Element Simulation

Science.gov (United States)

Li, Fengxian; Yi, Jianhong; Eckert, Jürgen

2017-12-01

Powder forged connecting rods have the problem of non-uniform density distributions because of their complex geometric shape. The densification behaviors of powder metallurgy (PM) connecting rod preforms during hot forging processes play a significant role in optimizing the connecting rod quality. The deformation behaviors of a connecting rod preform, a Fe-3Cu-0.5C (wt pct) alloy compacted and sintered by the powder metallurgy route (PM Fe-Cu-C), were investigated using the finite element method, while damage and friction behaviors of the material were considered in the complicated forging process. The calculated results agree well with the experimental results. The relationship between the processing parameters of hot forging and the relative density of the connecting rod was revealed. The results showed that the relative density of the hot forged connecting rod at the central shank changed significantly compared with the relative density at the big end and at the small end. Moreover, the relative density of the connecting rod was sensitive to the processing parameters such as the forging velocity and the initial density of the preform. The optimum forging processing parameters were determined and presented by using an orthogonal design method. This work suggests that the processing parameters can be optimized to prepare a connecting rod with uniform density distribution and can help to better meet the requirements of the connecting rod industry.

Weldability and mechanical property characterization of weld clad alloy 800H tubesheet forging

International Nuclear Information System (INIS)

King, J.F.; McCoy, H.E.

1984-09-01

The weldability of an alloy 800H forging that simulates a steam generator tubesheet is studied. Weldability was of concern because a wide range of microstructures was present in this forging. The top and portions of the bottom were weld clad with ERNiC-3 weld metal to a thickness of 19 mm similar to that anticipated for HTGR steam generators. Examinations of the clad fusion line in various regions revealed no weldability problems except possibly on the bottom portion, which contained large grains and some as-cast structure. A few microfissures were evident in this region, but no excessive hot cracking tendency was observed. The tensile properties in all areas of the clad forging were reasonable and not influenced greatly by the microstructure. The elevated-temperature tests showed strong tendency for fracture in the heat-affected zone of the alloy 800H. Creep failure at 649 0 C consistently occurred in the heat-affected zone of the alloy 800H, but the creep strength exceeded the expected values for alloy 800H

Material Behavior Based Hybrid Process for Sheet Draw-Forging Thin Walled Magnesium Alloys

International Nuclear Information System (INIS)

Sheng, Z.Q.; Shivpuri, R.

2005-01-01

Magnesium alloys are conventionally formed at the elevated temperatures. The thermally improved formability is sensitive to the temperature and strain rate. Due to limitations in forming speeds, tooling strength and narrow processing windows, complex thin walled parts cannot be made by traditional warm drawing or hot forging processes. A hybrid process, which is based on the deformation mechanism of magnesium alloys at the elevated temperature, is proposed that combines warm drawing and hot forging modes to produce an aggressive geometry at acceptable forming speed. The process parameters, such as temperatures, forming speeds etc. are determined by the FEM modeling and simulation. Sensitivity analysis under the constraint of forming limits of Mg alloy sheet material and strength of tooling material is carried out. The proposed approach is demonstrated on a conical geometry with thin walls and with bottom features. Results show that designed geometry can be formed in about 8 seconds, this cannot be formed by conventional forging while around 1000s is required for warm drawing. This process is being further investigated through controlled experiments

Controlled austempering of hammer forgings aimed at pseudo normalized microstructure directly after deformation

Directory of Open Access Journals (Sweden)

P. Skubisz

2017-01-01

Full Text Available The study concerns cost-effective realization of controlled thermomechanical processing (CTMP of medium-carbon and HSLA steel aimed at producing microstructure and properties equivalent to normalized condition directly after forging. The results of theoretical and physical modeling of hot forging with subsequent heat treating adopted for industrial realization in continuous manner were verified in semi-industrial conditions of a forge plant.

Research on Energy-Saving Production Scheduling Based on a Clustering Algorithm for a Forging Enterprise

Directory of Open Access Journals (Sweden)

Yifei Tong

2016-02-01

Full Text Available Energy efficiency is a buzzword of the 21st century. With the ever growing need for energy efficient and low-carbon production, it is a big challenge for high energy-consumption enterprises to reduce their energy consumption. To this aim, a forging enterprise, DVR (the abbreviation of a forging enterprise, is researched. Firstly, an investigation into the production processes of DVR is given as well as an analysis of forging production. Then, the energy-saving forging scheduling is decomposed into two sub-problems. One is for cutting and machining scheduling, which is similar to traditional machining scheduling. The other one is for forging and heat treatment scheduling. Thirdly, former forging production scheduling is presented and solved based on an improved genetic algorithm. Fourthly, the latter is discussed in detail, followed by proposed dynamic clustering and stacking combination optimization. The proposed stacking optimization requires making the gross weight of forgings as close to the maximum batch capacity as possible. The above research can help reduce the heating times, and increase furnace utilization with high energy efficiency and low carbon emissions.

Improvement of mechanical properties of zirconia-toughened alumina by sinter forging

NARCIS (Netherlands)

He, Y.; Winnubst, Aloysius J.A.; Verweij, H.; Burggraaf, Anthonie; Burggraaf, A.J.

1994-01-01

ZTA powder with a composition of 85 wt% alumina/15 wt% zirconia was prepared by a gel precipitation method. Sinter forging was performed with this powder to enhance the mechanical properties of ZTA materials. The influence of processing flaws on mechanical properties of sinter forged materials and

The investigation of crimes refering to forgery of documents and possession of forged documents

OpenAIRE

Kotovienė, Danutė

2011-01-01

THE INVESTIGATION OF CRIMES REFERING TO FORGERY OF DOCUMENTS AND POSSESSION OF FORGED DOCUMENTS Constantly improving informational technologies more and more get into our daily routine: nowadays it is widely spread internet payments, purchases, signing on-line agreements using electronic signatures. However, paper documents or other made of appropriate materials, which have material evidence, still have a very significant impact on our life. Its convey different aspects of states’ public work...

Comparative Thermal Aging Effects on PM-HIP and Forged Inconel 690

Science.gov (United States)

Bullens, Alexander L.; Bautista, Esteban; Jaye, Elizabeth H.; Vas, Nathaniel L.; Cain, Nathan B.; Mao, Keyou; Gandy, David W.; Wharry, Janelle P.

2018-03-01

This study compares thermal aging effects in Inconel 690 (IN690) produced by forging and powder metallurgy with hot isostatic pressing (PM-HIP). Isothermal aging is carried out over 400-800°C for up to 1000 h and then metallography and nanoindentation are utilized to relate grain microstructure with hardness and yield strength. The PM-HIP IN690 maintains a constant grain size through all aging conditions, while the forged IN690 exhibits limited grain growth at the highest aging temperature and longest aging time. The PM-HIP IN690 exhibits comparable mechanical integrity as the forged material throughout aging: hardness and yield strength are unchanged with 100 h aging, but increase after 1000 h aging at all temperatures. In both the PM-HIP and forged IN690, the Hall-Petch relationship for Ni-based superalloys predicts yield strength for 0-100 h aged specimens, but underestimates yield strength in the 1000 h aged specimens because of thermally induced precipitation.

Influence of segregations and hydrogen flakes on the mechanical properties of forged RPV steels

International Nuclear Information System (INIS)

Eiselt, C.C.; May, J.; Hein, H.

2013-01-01

In the frame of relevant 1970s/80s German research programs (e.g. FKS research program on component safety and others), many investigations on large forgings manufactured from Reactor Pressure Vessel (RPV) materials such as 20 MnMoNi 5 5 and 22 NiMoCr 3 7 have been performed. Lately, after ultrasonic testing hydrogen flakes in connection with segregation zones have been observed in a few RPV forgings. The earlier R and D programs contained a number of special heats, which covered a defined defect state (lower bound heats) with relevance to the recent observations of numerous UT indications in RPV forgings of two PWRs. Therefore, the results of these former research programs were now reviewed. The studies included an evaluation of the effects of macro/micro segregations as well as hydrogen flakes on the mechanical properties. As part of the mechanical technological experiments Charpy impact tests in different orientations (e.g. L-T, T-L and S-T) together with fracture mechanics and large scale tensile tests were carried out in segregated and non segregated material zones. In this context the letters L,T,S indicate the longitudinal, transversal and short transverse (thickness) direction with respect to rolling direction of the forging axis. The first letter indicates the direction of the principal stress, while the second letter stands for the crack propagation direction [1]. Furthermore the irradiation behavior of segregated material regions was analyzed and compared to non segregated material regions. Key results of these analyses indicate that in most cases upper shelf levels are lowered in segregated material parts compared to non segregated areas. In addition the segregations cause a larger scattering of impact energies. A high hydrogen content in combination with segregations has overall detrimental effects on the mechanical properties. However, there seems to be no specific segregation influence on the materials' irradiation reaction.

Tensile properties of a dual-axial forged Ti–Fe–Cu alloy containing boron

Energy Technology Data Exchange (ETDEWEB)

Zadorozhnyy, V.Yu., E-mail: zadorozhnyyvlad@gmail.com [National University of Science and Technology “MISIS”, Leninsky prospect, 4, Moscow 119049 (Russian Federation); Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan); Shchetinin, I.V.; Chirikov, N.V. [National University of Science and Technology “MISIS”, Leninsky prospect, 4, Moscow 119049 (Russian Federation); Louzguine-Luzgin, D.V. [WPI Advanced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan)

2014-09-22

In the present work we introduce a micro/nano-structured α+β Ti-based low-alloy produced by the tilt-casting method and subjected to subsequent thermo-mechanical treatment. After hot dual-axial forging at 900 °C, subsequent heating at 700 °C and water quenching a Ti{sub 94}Fe{sub 3}Cu{sub 3}+1000 ppm of boron alloy, containing inexpensive alloying elements, showed an ultimate tensile strength value of about 950 MPa and percentage elongation of about 5.2%. It is shown that the intensive forging treatment and subsequent heat treatment are leading to significantly improved mechanical properties of such an alloy compared to the as-cast state.

DETERMINATION OF THE OPTIMAL TEMPERING TEMPERATURE IN HARD FACING OF THE FORGING DIES

Directory of Open Access Journals (Sweden)

Milan Mutavdžić

2012-06-01

Full Text Available Here is analyzed selection of the optimal technology for heat treatment during the reparation of the damaged forging dies. Those tools are manufactured from alloyed tool steels for operation at elevated temperatures. Those steels are prone to self-hardening, so in reparatory hard-facing they must be preheated, additionally heated and tempered. During the tempering, in temperature interval 500-600°C, a secondary increase of hardness and decrease of impact toughness occurs, the so-called reversible tempering brittleness. Here is shown that it can be avoided by application of metallurgical and technological measures. Metallurgical measures assume adequate selection of steels. Since the considered steels are per se prone to tempering brittleness, we conducted experimental investigations to define the technological measures to avoid it. Tests on models were conducted: tempering from different temperatures, slow heating and cooling in still air. Hardness measurements showed that at 520°C, the secondary increase of hardness occurs, with drop of the impact toughness. Additional hard-facing tests included samples tempered at various regimes. Samples were prepared for mechanical and metallographic investigations. Results presented illustrate influence of additional heat treatment on structure, hardness and mechanical properties of the hard-faced layers. This enabled establishing the possibility of avoiding the tempering brittleness through technological measures.

Determination of the optimal tempering temperature in hard facing of the forging dies

Directory of Open Access Journals (Sweden)

Milan Mutavdžić

2012-05-01

Full Text Available Here is analyzed selection of the optimal technology for heat treatment during the reparation of the damaged forging dies. Those tools are manufactured from alloyed tool steels for operation at elevated temperatures. Those steels are prone to self-hardening, so in reparatory hard-facing they must be preheated, additionally heated and tempered. During the tempering, in temperature interval 500-600°C, a secondary increase of hardness and decrease of impact toughness occurs, the so-called reversible tempering brittleness. Here is shown that it can be avoided by application of metallurgical and technological measures. Metallurgical measures assume adequate selection of steels. Since the considered steels are per se prone to tempering brittleness, we conducted experimental investigations to define the technological measures to avoid it. Tests on models were conducted: tempering from different temperatures, slow heating and cooling in still air. Hardness measurements showed that at 520°C, the secondary increase of hardness occurs, with drop of the impact toughness. Additional hard-facing tests included samples tempered at various regimes. Samples were prepared for mechanical and metallographic investigations. Results presented illustrate influence of additional heat treatment on structure, hardness and mechanical properties of the hard-faced layers. This enabled establishing the possibility of avoiding the tempering brittleness through technological measures. 

Fatigue in cold-forging dies: Tool life analysis

DEFF Research Database (Denmark)

Skov-Hansen, P.; Bay, Niels; Grønbæk, J.

1999-01-01

In the present investigation it is shown how the tool life of heavily loaded cold-forging dies can be predicted. Low-cycle fatigue and fatigue crack growth testing of the tool materials are used in combination with finite element modelling to obtain predictions of tool lives. In the models...... the number of forming cycles is calculated first to crack initiation and then during crack growth to fatal failure. An investigation of a critical die insert in an industrial cold-forging tool as regards the influence of notch radius, the amount and method of pre-stressing and the selected tool material...

Manufacturing of large and integral-type steel forgings for nuclear steam supply system components

International Nuclear Information System (INIS)

Kawaguchi, S.; Tsukada, H.; Suzuki, K.; Sato, I.; Onodera, S.

1986-01-01

Forgings for the reactor pressure vessel (RPV) of the pressurized heavy water reactor (PHWR) 700 MWe, which is composed of seven major parts and nozzles totaling about 965 tons, were successfully developed. These forgings are: 1. Flanges: an outside diameter of 8440 mm and a weight of 238 tons max, requiring an ingot of 570 tons. 2. Shells and torus: an outside diameter of about 8000 mm with large height. 3. Cover dome: a diameter of 6800 mm and a thickness of 460 mm, requiring a blank forging before forming of 8000 mm in diameter and 550 m thick. The material designation is 20Mn-Mo-Ni 5 5 (equivalent to SA508, Class 3). In this paper, the manufacturing of and the properties of such large and integral forgings are discussed, including an overview of manufacturing processes for ultralarge-sized forgings over the last two decades

Evolution of the Ultrasonic Inspection of Heavy Rotor Forgings Over the Last Decades

Science.gov (United States)

Zimmer, A.; Vrana, J.; Meiser, J.; Maximini, W.; Blaes, N.

2010-02-01

All types of heavy forgings that are used in energy machine industry, rotor shafts as well as discs, retaining rings or tie bolts are subject to extensive nondestructive inspections before they are delivered to the customer. Due to the availability of the parts in simple shapes, these forgings are very well suited for full volmetric inspections using ultrasound. In the beginning, these inspections were carried out manually, using straight beam probes and analogue equipment. Higher requirements in reliability, efficiency, safety and power output in the machines have lead to higher requirements for the ultrasonic inspection in the form of more scanning directions, higher sensitivity demands and improved documentation means. This and the increasing use of high alloy materials for ever growing parts, increase the need for more and more sophisticated methods for testing the forgings. Angle scans and sizing technologies like DGS have been implemented, and for more than 15 years now, mechanized and automated inspections have gained importance since they allow better documentation as well as easier evaluation of the recorded data using different views (B- C- or D-Scans), projections or tomography views. The latest major development has been the availability of phased array probes to increase the flexibility of the inspection systems. Many results of the ongoing research in ultrasonic's have not been implemented yet. Today's availability of fast computers, large and fast data storages allows saving RF inspection data and applying sophisticated signal processing methods. For example linear diffraction tomography methods like SAFT offer tools for 3D reconstruction of inspection data, simplifying sizing and locating of defects as well as for improving signal to noise ratios. While such methods are already applied in medical ultrasonic's, they are still to be implemented in the steel industry. This paper describes the development of the ultrasonic inspection of heavy forgings

New design of process for cold forging to improve multi-stage gas fitting

Directory of Open Access Journals (Sweden)

Han-Sung Huang

2016-04-01

Full Text Available This work develops a process that solves the problem of the formation of cracks inside forged gas fittings in the cold forging process that arises from poor forging process design. DEFORM-3D forming software was utilized, and macroscopic experiments with optical microscopy and scanning electron microscopy were conducted to investigate the processed structures and the distribution therein of metal flow lines, and to find the internal micro-cracks to determine whether the cold forging process is reasonable. Analytical results herein demonstrate that the stress and strain inside the gas fitting can be elucidated using metal forming software. Together with experimental results, they demonstrate that a concentration of stress damages the workpiece in the forming process. Moreover, as metal flow lines become narrower, the workpiece becomes more easily damaged. Consequently, the improved cold forging process that is described in this work should be utilized to reduce the occurrence of fine cracks and defects. Planning for proper die design and production, increasing the quality of products, and reducing the number of defective products promote industrial competitiveness.

Managing Tensions And Forging Creative Synergies Between ...

African Journals Online (AJOL)

Managing Tensions And Forging Creative Synergies Between Indigenous And Modern Settlement Planning Concepts And Practices: Lessons For The Design And Planning For Sustainable Settlements And Built-Forms In Southern Africa.

Strain-induced grain growth of cryomilled nanocrystalline Al in trimodal composites during forging

International Nuclear Information System (INIS)

Yao, B.; Simkin, B.; Majumdar, B.; Smith, C.; Bergh, M. van den; Cho, K.; Sohn, Y.H.

2012-01-01

Highlights: ► Grain growth of cryomilled nanocrystalline aluminum during hot forging. ► Use of hollow cone dark field imaging technique in TEM for grain size measurement. ► Grain growth model of strain, strain rate and temperature for forging optimization. - Abstract: Grain growth of nanocrystalline aluminum ( nc Al) in trimodal Al metal-matrix-composites (MMCs) during hot forging was investigated. The nc Al phase formed through cryomilling of inert gas-atomized powders in liquid nitrogen has an average grain size down to 21 nm, exhibits excellent thermal stability. However, substantial grain growth of nc Al up to 63 nm was observed when the Al MMCs were thermo-mechanically processed even at relatively low temperatures. Grain growth of the cryomilled nc Al phase in trimodal Al MMCs after hot forging was documented with respect to temperature ranging from 175 °C to 287 °C, true strain ranging from 0.4 to 1.35 and strain rate ranging from 0.1 to 0.5 s −1 . Hollow cone dark field imaging technique was employed to provide statistically confident measurements of nc Al grain size that ranged from 21 to 63 nm. An increase in forging temperature and an increase in true strain were correlated with an increase in grain size of nc Al. Results were correlated to devise a phenomenological grain growth model for forging that takes strain, strain rate and temperature into consideration. Activation energy for the grain growth during thermo-mechanical hot-forging was determined to be 35 kJ/mol, approximately a quarter of activation energy for bulk diffusion of Al and a half of activation energy for static recrystallization.

Sensitivity Analysis of Oxide Scale Influence on General Carbon Steels during Hot Forging

Directory of Open Access Journals (Sweden)

Bernd-Arno Behrens

2018-02-01

Full Text Available Increasing product requirements have made numerical simulation into a vital tool for the time- and cost-efficient process design. In order to accurately model hot forging processes with finite, element-based numerical methods, reliable models are required, which take the material behaviour, surface phenomena of die and workpiece, and machine kinematics into account. In hot forging processes, the surface properties are strongly affected by the growth of oxide scale, which influences the material flow, friction, and product quality of the finished component. The influence of different carbon contents on material behaviour is investigated by considering three different steel grades (C15, C45, and C60. For a general description of the material behaviour, an empirical approach is used to implement mathematical functions for expressing the relationship between flow stress and dominant influence variables like alloying elements, initial microstructure, and reheating mode. The deformation behaviour of oxide scale is separately modelled for each component with parameterized flow curves. The main focus of this work lies in the consideration of different materials as well as the calculation and assignment of their material properties in dependence on current process parameters by application of subroutines. The validated model is used to carry out the influence of various oxide scale parameters, like the scale thickness and the composition, on the hot forging process. Therefore, selected parameters have been varied within a numerical sensitivity analysis. The results show a strong influence of oxide scale on the friction behaviour as well as on the material flow during hot forging.

Forged Signature Distinction Using Convolutional Neural Network for Feature Extraction

Directory of Open Access Journals (Sweden)

Seungsoo Nam

2018-01-01

Full Text Available This paper proposes a dynamic verification scheme for finger-drawn signatures in smartphones. As a dynamic feature, the movement of a smartphone is recorded with accelerometer sensors in the smartphone, in addition to the moving coordinates of the signature. To extract high-level longitudinal and topological features, the proposed scheme uses a convolution neural network (CNN for feature extraction, and not as a conventional classifier. We assume that a CNN trained with forged signatures can extract effective features (called S-vector, which are common in forging activities such as hesitation and delay before drawing the complicated part. The proposed scheme also exploits an autoencoder (AE as a classifier, and the S-vector is used as the input vector to the AE. An AE has high accuracy for the one-class distinction problem such as signature verification, and is also greatly dependent on the accuracy of input data. S-vector is valuable as the input of AE, and, consequently, could lead to improved verification accuracy especially for distinguishing forged signatures. Compared to the previous work, i.e., the MLP-based finger-drawn signature verification scheme, the proposed scheme decreases the equal error rate by 13.7%, specifically, from 18.1% to 4.4%, for discriminating forged signatures.

Fatigue behavior of rolled and forged tungsten at 25°, 280° and 480 °C

International Nuclear Information System (INIS)

Habainy, J.; Iyengar, S.; Lee, Y.; Dai, Y.

2015-01-01

Pure tungsten has been chosen as the target material at the European Spallation Source facility in Lund. Calculations show that the target temperature can reach 500 °C momentarily during the spallation process, leading to thermal fatigue. Target life estimations require fatigue data at different temperatures and this work focuses on generating such data for pure, unirradiated, rolled and forged tungsten in the range 25°–480 °C. For specimens oriented in the rolling direction, tensile tests at room temperature indicated Young's modulus values in the range 320–390 GPa, low levels of plasticity (<0.23%) and UTS values in the range 397 MPa (unpolished) and 705 MPa (Polished). UTS for forged specimens were around 500 MPa. Stress-controlled fatigue tests were conducted in the tensile regime, with a runout limit of 2 × 10"6 cycles. At 25 °C, unpolished specimens had fatigue limits of 150 MPa (rolling and transverse direction), and 175 MPa (forged). For polished specimens in the rolling direction, fatigue limits were higher at 237.5 MPa (25 °C) and 252.5 MPa (280 °C). The forged specimens showed slightly better fatigue properties and marginal cyclic hardening at 480 °C. - Highlights: • Stress & strain-controlled fatigue tests on pure tungsten at 25°, 280° & 480 °C. • Unirradiated, rolled and forged specimens in polished and unpolished condition. • Min. tensile strength (MPa): 397 (25 °C), 472 (280 °C) and 363 (480 °C). • Min. endurance limit (MPa): 137.5 (25 °C), 250 (280 °C) and 150 (480 °C). • Marginal cyclic hardening observed at 480 °C.

Development of seamless forged pipe and fitting for BWR recirculation loop piping with improved resistance to intergranular stress corrosion cracking

International Nuclear Information System (INIS)

Ohnishi, Keizo; Tsukada, Hisashi; Kobayashi, Masayoshi; Iwadate, Tadao; Ono, Shinichi

1981-01-01

As a primary remedy for IGSCC of primary loop piping, especially Recirculation Loop Piping of BWR, extra low carbon stainless steel with high nitrogen content has become to be used. While, in order to make In-service Inspection easier and complete, new design of piping which decrease both number and total length of weld line has been considered. Japan Steel Works has developed the research on large size seamless forged pipe and fitting made from high nitrogen extra low carbon 316 stainless steel. This paper describes the key points of manufacturing technology as well as the material properties, especially strength and intergranular-corrosion and intergranular- stress-corrosion-cracking-resistivities of these forged pipe and fitting. (author)

76 FR 30200 - Forging Machines; Extension of the Office of Management and Budget's (OMB) Approval of...

Science.gov (United States)

2011-05-24

...] Forging Machines; Extension of the Office of Management and Budget's (OMB) Approval of Information... extend OMB approval of the information collection requirements contained in the Forging Machines Standard... to reduce employees' risk of death or serious injury by ensuring that forging machines used by them...

Effect of Forging Allowance Value on the Power Consumption of Machining Process

Directory of Open Access Journals (Sweden)

L. D. Mal'kova

2015-01-01

Full Text Available The paper aim is to develop and study possible energy-efficiency measures for machined forgings drawing on analysis of the impact of the allowance for machining and its scatter.The most sophisticated option to take into consideration the effect of the cut depth is the work-piece machining in which the forging allowance value results from the blank production.Research of power consumption was conducted for turning the cylindrical surface of 144 mm length and  1,5 33 0,5   diameter on forgings of the work-pieces "screw of steering control" made from steel 60PP. A radial dimension allowance at said cylindrical surface at six points of the five sections was sized to assess the allowance value dispersion. The size of the sample measurements at the control points was n = 600. Statistic processing has shown normal law of distribution and sample homogeneity.To analyze the results of experiments was calculated a range of allowances for this workpiece. Calculated minimum and maximum allowance per one side for rough lathing were, respectively, 0.905 mm and 1.905mm. It was found that 77% points under control lie in calculated range of allowance values. And there are no points out of the range on lesser side that proves a lack of rejects; but there are points out of the range on the bigger side, that will require additional costs for machining the specified surface, including the cost of electricity.There were three power consumption calculations based on factory- recommended duty: for processing the entire sample of forgings with an average allowance, for machining forgings allowances of which are within the recommended design range of allowance, and for processing the entire sample of forgings with a minimum value of allowance.It was found that elimination of allowance values which are outside the recommended range enables to reduce the power consumption, at least, by 6%, and the overall power consumption for processing the measured forgings

A coupled thermo-mechanical pseudo inverse approach for preform design in forging

Science.gov (United States)

Thomas, Anoop Ebey; Abbes, Boussad; Li, Yu Ming; Abbes, Fazilay; Guo, Ying-Qiao; Duval, Jean-Louis

2017-10-01

Hot forging is a process used to form difficult to form materials as well as to achieve complex geometries. This is possible due to the reduction of yield stress at high temperatures and a subsequent increase in formability. Numerical methods have been used to predict the material yield and the stress/strain states of the final product. Pseudo Inverse Approach (PIA) developed in the context of cold forming provides a quick estimate of the stress and strain fields in the final product for a given initial shape. In this paper, PIA is extended to include the thermal effects on the forging process. A Johnson-Cook thermo-viscoplastic material law is considered and a staggered scheme is employed for the coupling between the mechanical and thermal problems. The results are compared with available commercial codes to show the efficiency and the limitations of PIA.

Manufacture of large monoblock LP rotor forgings and their quality

International Nuclear Information System (INIS)

Suzuki, Akira; Kinoshita, Shushi; Kohno, Masayoshi; Miyakawa, Mutsuhiro; Kikuchi, Hideo

1986-01-01

This paper describes the manufacturing and the quality of large monoblock low pressure rotors forged from 360 ton and 420 ton ingots. To obtain good and homogenous mechanical properties throughout a rotor, a computer was used to determine the heat treatment conditions. It was found that the technique was very effective at predicting mechanical properties of a monoblock rotor. Mechanical properties including the fracture toughness and fatigue crack propagation characteristics of monoblock rotor forgings proved satisfactory. (author)

Identification of forged Bank of England £20 banknotes using IR spectroscopy.

Science.gov (United States)

Sonnex, Emily; Almond, Matthew J; Baum, John V; Bond, John W

2014-01-24

Bank of England notes of £20 denomination have been studied using infrared spectroscopy in order to generate a method to identify forged notes. An aim of this work was to develop a non-destructive method so that a small, compact Fourier transform infrared spectrometer (FT-IR) instrument could be used by bank workers, police departments or others such as shop assistants to identify forged notes in a non-lab setting. The ease of use of the instrument is the key to this method, as well as the relatively low cost. The presence of a peak at 1400 cm(-1) arising from νasym (CO3(2-)) from the blank paper section of a forged note proved to be a successful indicator of the note's illegality for the notes that we studied. Moreover, differences between the spectra of forged and genuine £20 notes were observed in the ν(OH) (ca. 3500 cm(-1)), ν(C-H) (ca. 2900 cm(-1)) and ν(C=O) (ca. 1750 cm(-1)) regions of the IR spectrum recorded for the polymer film covering the holographic strip. In cases where these simple tests fail, we have shown how an infrared microscope can be used to further differentiate genuine and forged banknotes by producing infrared maps of selected areas of the note contrasting inks with background paper. Copyright © 2013 Elsevier B.V. All rights reserved.

Identification of forged Bank of England £20 banknotes using IR spectroscopy

Science.gov (United States)

Sonnex, Emily; Almond, Matthew J.; Baum, John V.; Bond, John W.

2014-01-01

Bank of England notes of £20 denomination have been studied using infrared spectroscopy in order to generate a method to identify forged notes. An aim of this work was to develop a non-destructive method so that a small, compact Fourier transform infrared spectrometer (FT-IR) instrument could be used by bank workers, police departments or others such as shop assistants to identify forged notes in a non-lab setting. The ease of use of the instrument is the key to this method, as well as the relatively low cost. The presence of a peak at 1400 cm-1 arising from νasym (CO32-) from the blank paper section of a forged note proved to be a successful indicator of the note's illegality for the notes that we studied. Moreover, differences between the spectra of forged and genuine £20 notes were observed in the ν(OH) (ca. 3500 cm-1), ν(Csbnd H) (ca. 2900 cm-1) and ν(Cdbnd O) (ca. 1750 cm-1) regions of the IR spectrum recorded for the polymer film covering the holographic strip. In cases where these simple tests fail, we have shown how an infrared microscope can be used to further differentiate genuine and forged banknotes by producing infrared maps of selected areas of the note contrasting inks with background paper.

The relationship between UT reported size and actual size of the defects in rotor forgings

International Nuclear Information System (INIS)

Seong, Un Hak; Kim, Jeong Tae; Park, Yun Sik

2003-01-01

In order to evaluate the reliability of rotor forgings, it is very important to know the actual size of the defects in the rotor forgings. The determination of the defect size requires the accurate non-destructive measurement. However, there may be some differences between the reported size with the ultrasonic non-destructive testing method and the actual size of defects. These differences may be a severe cause of errors in evaluation of rotor forgings. So, the calculated size with 'Master Curve' considering safety factor, which is usually larger than the reported size, has been used in evaluation of rotor forgings. The relation between the EFBH (Equivalent Flat Bottom Hole) size measured by non-destructive method and the actual size by destructive method in many rotors manufactured at Doosan was investigated. In this investigation 'Master Curve' compensating the differences between UT reported size and actual size of defects in our rotor forgings was obtainable. The applicability of this 'Master Curve' as a way of calculating the actual defect size was also investigated. For the evaluation of rotor forgings, it is expected that this 'Master Curve' may be used to determine the accurate actual size of defects.

The relationship between UT reported size and actual size of the defects in rotor forgings

International Nuclear Information System (INIS)

Seong, Un Hak; Kim, Jeong Tae; Park, Yun Sik

2003-01-01

In order to evaluate the reliability of rotor forgings, it is very important to know the actual size of the defects in the rotor forgings. The determination of the defect size requires the accurate non-destructive measurement. However, there may be some difference between the reported size with ultrasonic non-destructive testing method and the actual size of defects. These differences may be a severe cause of errors in evaluation of rotor forgings. So, the calculated size with 'Master Curve' considering safety factor, which is usually larger than the reported size, has been used in evaluation of rotor forgings. The relation between the EFBH (Equivalent Flat Bottom Hole) size measured by non-destructive method and the actual size by destructive method in many rotors manufactured at Doosan was investigated. In this investigation, 'Master Curve' compensating the differences between UT reported size and actual size of defects in our rotor forgings was obtainable. The applicability of this 'Master Curve' as a way of calculating the actual defect size was also investigated. For the evaluation of rotor forgings, it is expected that this 'Master Curve' may be used to determine the accurate actual size of defects.

Fabrication and properties of Y-Ba-Cu-O high Tc superconductor by upset-forging method

International Nuclear Information System (INIS)

Chang, Ho Jung; Kang, Kae Myung; Song, Jin Tae

1990-01-01

YBa 2 Cu 3 O 7-x oxide superconductors was fabricated by sintering process and upset-forging method, respectively, and microstructures and conduction properties were compared. There was no difference in crystal structure the (001) x-ray reflection presumably due to preferred crystal orientation of the YBa 2 Cu 3 O 7-x superconductor. Furthermore, the grain size of the 123-phase increased as the reduction ratio became larger during the upset-forging. The critical temperature for zero resistivity of both samples was almost the same, i.e., about 90K. These results have demonstrated the potential of producing YBa 2 Cu 3 O 7-x superconducting wire or tape effectively using a upset-forging method. The critical current density of the upset-forged sample, however, was lower than that of the sintered one, which fact might be ascribed to microcrack formation during fast upset-forging. (Author)

Repetitive forging (RF) using inclined punches as a new bulk severe plastic deformation method

Energy Technology Data Exchange (ETDEWEB)

Babaei, A. [Department of Mechanical Engineering, University College of Engineering, University of Tehran, Tehran 11155-4563 (Iran, Islamic Republic of); Faraji, G., E-mail: ghfaraji@ut.ac.ir [Department of Mechanical Engineering, University College of Engineering, University of Tehran, Tehran 11155-4563 (Iran, Islamic Republic of); Department of Engineering Design and Manufacture, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mashhadi, M.M. [Department of Mechanical Engineering, University College of Engineering, University of Tehran, Tehran 11155-4563 (Iran, Islamic Republic of); Hamdi, M. [Department of Engineering Design and Manufacture, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2012-12-15

A new bulk severe plastic deformation method based on repetitive forging (RF) using inclined punches is proposed. This process consists of two half cycles. In the first half cycle, a square cross section deforms to parallelogram by forging with two inclined punches, and the parallelogram cross section is forged back to square using two flat punches in the second half cycle. This method was applied to commercially pure copper and significant grain refinement was achieved after four passes of RF. The results showed that significant improvement in the mechanical properties was obtained. Notable increase of yield and ultimate strengths corresponding to 358 MPa and 381 MPa after four passes of RF from the initial values of 121 MPa and 230.5 MPa is detectable. Microhardness increases to about 100 Hv after four passes of RF from the initial value of 53 Hv. Finite element (FE) results illustrate that RF is able to impose extremely high plastic strains to the materials. In the RF process, the processed samples have the same dimensions and geometry as those of the initial sample without any waste material and there is no need for back pressure.

The coarsening effect of SA508-3 steel used as heavy forgings material

Directory of Open Access Journals (Sweden)

Dingqian Dong

2015-01-01

Full Text Available SA508Gr.3 steel is popularly used to produce core unit of nuclear power reactors due to its outstanding ability of anti-neutron irradiation and good fracture toughness. The forging process takes important role in manufacturing to refine the grain size and improve the material properties. But due to their huge size, heavy forgings cannot be cooled down quickly, and the refined grains usually have long time to grow in high temperature conditions. If the forging process is not adequately scheduled or implemented, very large grains up to millimetres in size may be found in this steel and cannot be eliminated in the subsequent heat treatment. To fix the condition which may causes the coarsening of the steel, hot upsetting experiments in the industrial production environment were performed under different working conditions and the corresponding grain sizes were measured and analysed. The observation showed that the grain will abnormally grow if the deformation is less than a critical value. The strain energy takes a critical role in the grain evolution. If dynamic recrystallization consumes the strain energy as much as possible, the normal grains will be obtained. While if not, the stored strain energy will promote abnormal growth of the grains.

Magnetostriction of heavily deformed Fe–Co binary alloys prepared by forging and cold rolling

International Nuclear Information System (INIS)

Yamaura, Shin-ichi; Nakajima, Takashi; Satoh, Takenobu; Ebata, Takashi; Furuya, Yasubumi

2015-01-01

Highlights: • The as-forged Fe 25 Co 75 alloy shows the magnetostriction of 108 ppm. • The as-cold rolled Fe 25 Co 75 alloy shows the magnetostriction of 140 ppm. • Magnetostriction of Fe–Co alloy reached the maximum in a single bcc state. • Fcc phase is harmful to the increase in magnetostriction of Fe–Co alloy. • Fcc phase precipitation in Fe–Co alloy can be suppressed by cold rolling. - Abstract: Magnetostriction of Fe 1−x Co x (x = 50–90 at%) alloys prepared by forging and subsequent cold-rolling was studied as functions of alloy compositions and thermomechanical treatments. Magnetostriction of the as-forged Fe 25 Co 75 alloy was 108 ppm and that of the as-cold rolled Fe 25 Co 75 alloy measured parallel to the rolling direction (RD) was 128 ppm. The cold-rolled Fe 25 Co 75 alloy possessed a nearly {1 0 0}<0 1 1> texture, leading to the maximum magnetostriction of 140 ppm when measured at an angle of 45° to RD. Moreover, the fully annealed Fe 25 Co 75 and Fe 20 Co 80 alloys were gradually cold rolled and magnetostriction were measured. Results showed that the magnetostriction of those cold-rolled alloys drastically increased with increasing reduction rate. According to the XRD and TEM observations, intensity of the fcc peak gradually decreased with increasing reduction rate and that the alloys became to be in a bcc single state at a reduction rate higher than 90%, leading to a drastic increase in magnetostriction

Manufacturing of Nanostructured Rings from Previously ECAE-Processed AA5083 Alloy by Isothermal Forging

Directory of Open Access Journals (Sweden)

C. J. Luis

2013-01-01

Full Text Available The manufacturing of a functional hollow mechanical element or ring of the AA5083 alloy previously equal channel angular extrusion (ECAE processed, which presents a submicrometric microstructure, is dealt with. For this purpose, the design of two isothermal forging dies (preform and final shape is carried out using the design of experiments (DOE methodology. Moreover, after manufacturing the dies and carrying out tests so as to achieve real rings, the mechanical properties of these rings are analysed as well as their microstructure. Furthermore, a comparison between the different forged rings is made from ECAE-processed material subjected to different heat treatments, previous to the forging stage. On the other hand, the ring forging process is modelled through the use of finite element simulation in order to improve the die design and to study the force required for the isothermal forging, the damage value, and the strain the material predeformed by ECAE has undergone. With this present research work, it is intended to improve the knowledge about the mechanical properties of nanostructured material and the applicability of this material to industrial processes that allow the manufacturing of functional parts.

Material saving by means of CWR technology using optimization techniques

Science.gov (United States)

Pérez, Iñaki; Ambrosio, Cristina

2017-10-01

Material saving is currently a must for the forging companies, as material costs sum up to 50% for parts made of steel and up to 90% in other materials like titanium. For long products, cross wedge rolling (CWR) technology can be used to obtain forging preforms with a suitable distribution of the material along its own axis. However, defining the correct preform dimensions is not an easy task and it could need an intensive trial-and-error campaign. To speed up the preform definition, it is necessary to apply optimization techniques on Finite Element Models (FEM) able to reproduce the material behaviour when being rolled. Meta-models Assisted Evolution Strategies (MAES), that combine evolutionary algorithms with Kriging meta-models, are implemented in FORGE® software and they allow reducing optimization computation costs in a relevant way. The paper shows the application of these optimization techniques to the definition of the right preform for a shaft from a vehicle of the agricultural sector. First, the current forging process, based on obtaining the forging preform by means of an open die forging operation, is showed. Then, the CWR preform optimization is developed by using the above mentioned optimization techniques. The objective is to reduce, as much as possible, the initial billet weight, so that a calculation of flash weight reduction due to the use of the proposed preform is stated. Finally, a simulation of CWR process for the defined preform is carried out to check that most common failures (necking, spirals,..) in CWR do not appear in this case.

Modelling and Testing of Friction in Forging

DEFF Research Database (Denmark)

Bay, Niels

2007-01-01

Knowledge about friction is still limited in forging. The theoretical models applied presently for process analysis are not satisfactory compared to the advanced and detailed studies possible to carry out by plastic FEM analyses and more refined models have to be based on experimental testing...

Forging Inclusive Solutions: Experiential Earth Charter Education

Science.gov (United States)

Hill, Linda D.

2010-01-01

Forging Inclusive Solutions describes the aims, methodology and outcomes of Inclusive Leadership Adventures, an experiential education curriculum for exploring the Earth Charter. Experiential education builds meaningful relationships, skills, awareness and an inclusive community based on the Earth Charter principles. When we meet people where they…

Magnetostriction of heavily deformed Fe–Co binary alloys prepared by forging and cold rolling

Energy Technology Data Exchange (ETDEWEB)

Yamaura, Shin-ichi, E-mail: yamaura@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan); Nakajima, Takashi [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan); Satoh, Takenobu; Ebata, Takashi [Tohoku Steel, Co., Ltd., 23 Nishigaoka, Murata, Murata-machi, Shibata 989-1393 (Japan); Furuya, Yasubumi [North Japan Research Institute for Sustainable Energy, Hirosaki University, 2-1-3 Matsubara, Aomori 030-0813 (Japan)

2015-03-15

Highlights: • The as-forged Fe{sub 25}Co{sub 75} alloy shows the magnetostriction of 108 ppm. • The as-cold rolled Fe{sub 25}Co{sub 75} alloy shows the magnetostriction of 140 ppm. • Magnetostriction of Fe–Co alloy reached the maximum in a single bcc state. • Fcc phase is harmful to the increase in magnetostriction of Fe–Co alloy. • Fcc phase precipitation in Fe–Co alloy can be suppressed by cold rolling. - Abstract: Magnetostriction of Fe{sub 1−x}Co{sub x} (x = 50–90 at%) alloys prepared by forging and subsequent cold-rolling was studied as functions of alloy compositions and thermomechanical treatments. Magnetostriction of the as-forged Fe{sub 25}Co{sub 75} alloy was 108 ppm and that of the as-cold rolled Fe{sub 25}Co{sub 75} alloy measured parallel to the rolling direction (RD) was 128 ppm. The cold-rolled Fe{sub 25}Co{sub 75} alloy possessed a nearly {1 0 0}<0 1 1> texture, leading to the maximum magnetostriction of 140 ppm when measured at an angle of 45° to RD. Moreover, the fully annealed Fe{sub 25}Co{sub 75} and Fe{sub 20}Co{sub 80} alloys were gradually cold rolled and magnetostriction were measured. Results showed that the magnetostriction of those cold-rolled alloys drastically increased with increasing reduction rate. According to the XRD and TEM observations, intensity of the fcc peak gradually decreased with increasing reduction rate and that the alloys became to be in a bcc single state at a reduction rate higher than 90%, leading to a drastic increase in magnetostriction.

A material based approach to creating wear resistant surfaces for hot forging

Science.gov (United States)

Babu, Sailesh

Tools and dies used in metal forming are characterized by extremely high temperatures at the interface, high local pressures and large metal to metal sliding. These harsh conditions result in accelerated wear of tooling. Lubrication of tools, done to improve metal flow drastically quenches the surface layers of the tools and compounds the tool failure problem. This phenomenon becomes a serious issue when parts forged at complex and are expected to meet tight tolerances. Unpredictable and hence uncontrolled wear and degradation of tooling result in poor part quality and premature tool failure that result in high scrap, shop downtime, poor efficiency and high cost. The objective of this dissertation is to develop a computer-based methodology for analyzing the requirements hot forging tooling to resist wear and plastic deformation and wear and predicting life cycle of forge tooling. Development of such is a system is complicated by the fact that wear and degradation of tooling is influenced by not only the die material used but also numerous process controls like lubricant, dilution ratio, forging temperature, equipment used, tool geometries among others. Phenomenological models available u1 the literature give us a good thumb rule to selecting materials but do not provide a way to evaluate pits performance in field. Once a material is chosen, there are no proven approaches to create surfaces out of these materials. Coating approaches like PVD and CVD cannot generate thick coatings necessary to withstand the conditions under hot forging. Welding cannot generate complex surfaces without several secondary operations like heat treating and machining. If careful procedures are not followed, welds crack and seldom survive forging loads. There is a strong need for an approach to selectively, reliably and precisely deposit material of choice reliably on an existing surface which exhibit not only good tribological properties but also good adhesion to the substrate

Fabrication Improvement of Cold Forging Hexagonal Nuts by Computational Analysis and Experiment Verification

Directory of Open Access Journals (Sweden)

Shao-Yi Hsia

2015-01-01

Full Text Available Cold forging has played a critical role in fasteners and has been applied to the automobile industry, construction industry, aerospace industry, and living products so that cold forging presents the opportunities for manufacturing more products. By using computer simulation, this study attempts to analyze the process of creating machine parts, such as hexagonal nuts. The DEFORM-3D forming software is applied to analyze the process at various stages in the computer simulation, and the compression test is also used for the flow stress equation in order to compare the differences between the experimental results and the equation that is built into the computer simulation software. At the same time, the metallography and hardness of experiments are utilized to understand the cold forging characteristics of hexagonal nuts. The research results would benefit machinery businesses to realize the forging load and forming conditions at various stages before the fastener formation. In addition to planning proper die design and production, the quality of the produced hexagonal nuts would be more stable to promote industrial competitiveness.

Influence of the Constitutive Flow Law in FEM Simulation of the Radial Forging Process

Directory of Open Access Journals (Sweden)

Olivier Pantalé

2013-01-01

Full Text Available Radial forging is a widely used forming process for manufacturing hollow products in transport industry. As the deformation of the workpiece, during the process, is a consequence of a large number of high-speed strokes, the Johnson-Cook constitutive law (taking into account the strain rate seems to be well adapted for representing the material behavior even if the process is performed under cold conditions. But numerous contributions concerning radial forging analysis, in the literature, are based on a simple elastic-plastic formulation. As far as we know, this assumption has yet not been validated for the radial forging process. Because of the importance of the flow law in the effectiveness of the model, our purpose in this paper is to analyze the influence of the use of an elastic-viscoplastic formulation instead of an elastic-plastic one for modeling the cold radial forging process. In this paper we have selected two different laws for the simulations: the Johnson-Cook and the Ludwik ones, and we have compared the results in terms of forging force, product's thickness, strains, stresses, and CPU time. For the presented study we use an AISI 4140 steel, and we denote a fairly good agreement between the results obtained using both laws.

On the domestically-made heavy forging for reactor pressure vessels of PWR nuclear power plant

International Nuclear Information System (INIS)

Pan Xiren; Zhang Chen.

1988-01-01

The present situation of the foreign heavy forgings for nuclear reactor pressure vessels and the heavy forgings condition which is used for the Qinshan 300MWe nuclear power plant are described. Some opinions of domestic products is proposed

Information Technology Industry 2004

National Research Council Canada - National Science Library

Altieri, Richard; Buccheit, Nathan; Burke, Kyle; Dillard, Norvel; Dolan, Patrick; Edwards, Gregory; Elins, Daniel; Gaines, Leonard; Goodwin, Steven; Lawrence, Michael

2004-01-01

Forging an unprecedented partnership between the public and private sectors is essential to protect the vital interests of the United States in the wake of the ongoing Information Technology Revolution...

Manufacturing and material properties of forgings for reactor pressure vessel of high temperature engineering test reactor

International Nuclear Information System (INIS)

Sato, I.; Suzuki, K.

1994-01-01

For the reactor pressure vessel (RPV) of high temperature engineering test reactor (HTTR) which has been developed by Japan Atomic Energy Research Institute (JAERI), 2 1/4Cr-1Mo steel is used first in the world. Material confirmation test has been carried out to demonstrate good applicability of forged low Si 2 1/4Cr-1Mo steel to the RPV of HTTR. Recently, JSW has succeeded in the manufacturing of large size ring forgings and large size forged cover dome integrated with nozzles for stand pipe for the RPV. This paper describes the results of the material confirmation test as well as the manufacturing and material properties of the large forged cover dome integrated with nozzles for stand pipe. (orig.)

Titanium Aluminide Casting Technology Development

Science.gov (United States)

Bünck, Matthias; Stoyanov, Todor; Schievenbusch, Jan; Michels, Heiner; Gußfeld, Alexander

2017-12-01

Titanium aluminide alloys have been successfully introduced into civil aircraft engine technology in recent years, and a significant order volume increase is expected in the near future. Due to its beneficial buy-to-fly ratio, investment casting bears the highest potential for cost reduction of all competing production technologies for TiAl-LPTB. However, highest mechanical properties can be achieved by TiAl forging. In view of this, Access e.V. has developed technologies for the production of TiAl investment cast parts and TiAl die cast billets for forging purposes. While these parts meet the highest requirements, establishing series production and further optimizing resource and economic efficiency are present challenges. In order to meet these goals, Access has recently been certified according to aircraft standards, aiming at qualifying parts for production on technology readiness level 6. The present work gives an overview of the phases of development and certification.

High-Temperature Oxidation Behavior and Kinetics of Forged 12Cr-MoVW Steel

Directory of Open Access Journals (Sweden)

Kim Yong Hwan

2017-06-01

Full Text Available The oxidation kinetics of forged 12Cr-MoVW steel was investigated in an air (N2+O2 atmosphere at 873-1073 K (Δ50 K using thermogravimetric analysis. The oxidized samples were characterized using X-ray diffraction, and the surface and cross-sectional morphologies were examined using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. The forged 12Cr-MoVW steel samples exhibited parabolic behavior and a low oxidation rate compared with their as-cast counterparts. A protective oxide layer was uniformly formed at relatively low temperature (≤973 K for the forged samples, which thus exhibited better oxidation resistance than the as-cast ones. These oxides are considered solid-solution compounds such as (Fe, Cr2O3.

Forging a unique nursing partnership with China.

Science.gov (United States)

Munn, Flavia

2017-07-12

When members of a London nursing faculty forged a learning partnership with a Chinese counterpart they likely did not expect to be discussing the benefits of using Florence Nightingale lamps to decorate hospital walls. But there is nothing ordinary about the collaboration between King's College London and Nanjing Health School.

[Research on the temperature field detection method of hot forging based on long-wavelength infrared spectrum].

Science.gov (United States)

Zhang, Yu-Cun; Wei, Bin; Fu, Xian-Bin

2014-02-01

A temperature field detection method based on long-wavelength infrared spectrum for hot forging is proposed in the present paper. This method combines primary spectrum pyrometry and three-stage FP-cavity LCTF. By optimizing the solutions of three group nonlinear equations in the mathematical model of temperature detection, the errors are reduced, thus measuring results will be more objective and accurate. Then the system of three-stage FP-cavity LCTF was designed on the principle of crystal birefringence. The system realized rapid selection of any wavelength in a certain wavelength range. It makes the response of the temperature measuring system rapid and accurate. As a result, without the emissivity of hot forging, the method can acquire exact information of temperature field and effectively suppress the background light radiation around the hot forging and ambient light that impact the temperature detection accuracy. Finally, the results of MATLAB showed that the infrared spectroscopy through the three-stage FP-cavity LCTF could meet the requirements of design. And experiments verified the feasibility of temperature measuring method. Compared with traditional single-band thermal infrared imager, the accuracy of measuring result was improved.

Modelling of Damage During Hot Forging of Ingots

DEFF Research Database (Denmark)

Christiansen, Peter; Hattel, Jesper Henri; Bay, Niels

2013-01-01

Ductile damage modelling in the ingot forging process is discussed. Advantages and disadvantages of both coupled and uncoupled ductile damage models are presented. Some uncoupled damage models are examined in greater detail regarding their applicability to different processes, where hydrostatic...

Forged hollows (alloy 617) for PNP-hot gas collectors

International Nuclear Information System (INIS)

Hofmann, F.

1984-01-01

When the partners in the PNP-Project decided to manufacture components, such as gas collectors, from material of type alloy 617, the problem arose that required semi-fabricated products, especially forged hollows weighing several tons each, were not available. As VDM (Vereinigte Deutsche Metallwerke AG) had already experience in production of other semi-fabricated products of this alloy, attempts were made based on this knowledge, to develop manufacturing methods for forged hollows. The aim was to produce hollows as long as possible, and to keep the welding cost minimum. Welded seams are always critical during fabrication, as well as during later inspection under actual operating conditions. The three stage plan used to perform the above task illustrates the development aims is described

Tool design and materials for electro sinter forging (ESF)

DEFF Research Database (Denmark)

Cannella, Emanuele; Nielsen, Chris Valentin

) process, the main requirement is the electrical current passing through the electrical conducting powder. To obtain this, a closed-die setup with electrical insulating properties was used. Furthermore, the alignment between the compacting punch and die needed to be ensured by pre-aligning or alternatively...... by using an alignment system. The present work is focused on the designing phase of a tool for the electro sinter forging of a disc, made from titanium powder. By applying a pre-alignment system, the setup resulted suitable for this application. A tool design for sintering rings is also showed....

Production of a 304 stainless steel nuclear reactor forging from a very large electroslag refined ingot

International Nuclear Information System (INIS)

Watkins, E.J.; Tihansky, E.L.

1986-01-01

A four-loop, upper barrel flange forging for a nuclear reactor was produced from what the authors believe to be the largest 304H grade stainless steel electroslag refined (ESR) ingot ever refined. The ingot was refined in a 1524-mm-diameter, ingot withdrawal-type ESR furnace using a lime-bearing slag, low-frequency a-c power, and dry air protection. Five electrodes were remelted in order to produce the desired ingot weight. The ingot was subsequently forged in a five-step operation on a 6800-metric-ton press to produce the desired barrel flange configuration. Testing of the finished machined forging revealed excellent tensile ductility, excellent ultrasonic penetrability, and good chemical uniformity with no macrosegregation. Overall quality was judged to be superior to previously produced, conventionally melted forgings

Forging Oxide-Dispersion-Strengthened Superalloys

Science.gov (United States)

Harf, F. H.; Glasgow, T. K.; Moracz, D. J.; Austin, C. M.

1986-01-01

Cladding of mild steel prevents surface cracking when alloy contacts die. Continual need for improvements in properties of alloys capable of withstanding elevated temperatures. Accomplished by using oxide-dispersion-strengthed superalloys such as Inconel Alloy MA 6000. Elevated tensile properties of forged alloy equal those of hot-rolled MA 6000 bar. Stress-rupture properties somewhat lower than those of bar stock but, at 1,100 degrees C, exceed those of strongest commercial single crystal, directionally solidified and conventionally cast superalloys.

Design of the Driving and Clamp Rotation Hydraulic Control System for the Heavy Load Forging Manipulator

Directory of Open Access Journals (Sweden)

Li Geqiang

2015-01-01

Full Text Available The manipulator was equipped with full hydraulic drive. We designed the hydraulic systems for the driving and clamping rotation. We used a fuzzy PID control strategy to design the electro-hydraulic proportional control system. We built a united simulation model based on the co-simulation of MATLAB/Simulink and AMEsim. A mathematical model of the system was also established. We did separate simulations of the system’s dynamic characteristics for fast forging and normal forging working conditions. The parameters were optimized. The field test shows that the steady-state error of the hydraulic system is small and the system response is fast. The system’s rapid response speed, high precision, and stability under heavy load were realized.

Highlight: Forging the new Indonesia-Canada partnership | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

15 avr. 2016 ... Canada's Centre for International Governance Innovation and Indonesia's Centre for Strategic and International Studies organized the Indonesia-Canada Bilateral Forum, Innovation and Change: Forging the New Indonesia-Canada Partnership. IDRC co-sponsored the meeting, held May 26-27, 2015.

Manufacturing involving forging of multiple objects in contact

DEFF Research Database (Denmark)

Nielsen, Chris Valentin; Zhang, W.; Martins, P.A.F.

and dissimilar materials. While being plastically deformed against each other under increasing forging load, the parts dynamically develop their mutual contact interfaces. Comparisons of the final geometry as well as force-displacement curves are evaluated. The potential of simulated applications are discussed...

Phased array inspection of large size forged steel parts

Science.gov (United States)

Dupont-Marillia, Frederic; Jahazi, Mohammad; Belanger, Pierre

2018-04-01

High strength forged steel requires uncompromising quality to warrant advance performance for numerous critical applications. Ultrasonic inspection is commonly used in nondestructive testing to detect cracks and other defects. In steel blocks of relatively small dimensions (at least two directions not exceeding a few centimetres), phased array inspection is a trusted method to generate images of the inside of the blocks and therefore identify and size defects. However, casting of large size forged ingots introduces changes of mechanical parameters such as grain size, the Young's modulus, the Poisson's ratio, and the chemical composition. These heterogeneities affect the wave propagation, and consequently, the reliability of ultrasonic inspection and the imaging capabilities for these blocks. In this context, a custom phased array transducer designed for a 40-ton bainitic forged ingot was investigated. Following a previous study that provided local mechanical parameters for a similar block, two-dimensional simulations were made to compute the optimal transducer parameters including the pitch, width and number of elements. It appeared that depending on the number of elements, backwall reconstruction can generate high amplitude artefacts. Indeed, the large dimensions of the simulated block introduce numerous constructive interferences from backwall reflections which may lead to important artefacts. To increase image quality, the reconstruction algorithm was adapted and promising results were observed and compared with the scattering cone filter method available in the CIVA software.

Effect of precipitates on microstructures and properties of forged Mg-10Gd-2Y-0.5Zn-0.3Zr alloy during ageing process

International Nuclear Information System (INIS)

Han, X.Z.; Xu, W.C.; Shan, D.B.

2011-01-01

Highlights: · The effect of forging process on microstructure evolution and mechanical properties of Magnesium alloy with rare earth was investigated. · The optimal mechanical properties of the alloy with high strength and enough elongation were obtained after forging and ageing process. · The strength improvement of the alloy after forging and ageing process mainly results from the precipitation of 14H-type LPSO phase. · Strengthening mechanism of the alloy is controlled by the precipitation of β' and 14H-type LPSO phases which can inhibit sliding of dislocations and growth of grain boundaries. - Abstract: The precipitate behavior during forging and ageing process of Mg-10Gd-2Y-0.5Zn-0.3Zr alloy has been investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The mechanical properties of the alloy after forging and ageing process have been evaluated using Vickers hardness and room-temperature tensile tests. The results show that precipitation of 14H-type long period stacking order (LPSO) phase is the main strengthening phase in the as-forged alloy. The LPSO phase and refinement of grains contribute to the strength improvement of the alloy after forging process. The optimal mechanical properties of the alloy are obtained when it is aged at 200 deg. C for 60 h, which mainly owes to the precipitation of large amounts of β' and 14H-type LPSO phases on the α-Mg matrix. The growth of secondary phases, widening of soft precipitate free zones and coarsening of grains during subsequent ageing process at higher temperature lead to the decrease of mechanical properties of the alloy.

Rapid Prototyping Technologies for Manufacturing and Maintenance Activities

Science.gov (United States)

Pfeifer, Marcel Rolf

2017-12-01

The paper deals with the direct application of Rapid Prototyping technologies for parts and spare parts production in production companies and the economic effect by making use of this technology. Traditional production technologies are technologies such as forging, cutting, machining, etc. These technologies are widely accepted and the teething troubles are solved. Rapid Prototyping technologies such as 3D printing on the other hand came into the focus in the recent years when the technologies and the produced quality gradually advanced. Providing flexibility and time efficiency the technology should also have a practical application in production. This paper has the aim to provide a case-study based on existing cost figures to show that these technologies are not limited to prototype developments.

Superplastic forging nitride ceramics

Science.gov (United States)

Panda, P.C.; Seydel, E.R.; Raj, R.

1988-03-22

A process is disclosed for preparing silicon nitride ceramic parts which are relatively flaw free and which need little or no machining, said process comprising the steps of: (a) preparing a starting powder by wet or dry mixing ingredients comprising by weight from about 70% to about 99% silicon nitride, from about 1% to about 30% of liquid phase forming additive and from 1% to about 7% free silicon; (b) cold pressing to obtain a preform of green density ranging from about 30% to about 75% of theoretical density; (c) sintering at atmospheric pressure in a nitrogen atmosphere at a temperature ranging from about 1,400 C to about 2,200 C to obtain a density which ranges from about 50% to about 100% of theoretical density and which is higher than said preform green density, and (d) press forging workpiece resulting from step (c) by isothermally uniaxially pressing said workpiece in an open die without initial contact between said workpiece and die wall perpendicular to the direction of pressing and so that pressed workpiece does not contact die wall perpendicular to the direction of pressing, to substantially final shape in a nitrogen atmosphere utilizing a temperature within the range of from about 1,400 C to essentially 1,750 C and strain rate within the range of about 10[sup [minus]7] to about 10[sup [minus]1] seconds[sup [minus]1], the temperature and strain rate being such that surface cracks do not occur, said pressing being carried out to obtain a shear deformation greater than 30% whereby superplastic forging is effected.

Electro sinter forging of titanium disks

DEFF Research Database (Denmark)

Cannella, Emanuele; Nielsen, Chris Valentin; Bay, Niels Oluf

by measuring the electrical resistance during the sintering process [5], since low electrical resistance corresponds to high density. It is, however, necessary to be aware that increased temperature, on the other hand, increases the resistance. SEM micrographs and Computed Tomography (CT) are carried out......Electro sinter forging (ESF) is a new sintering process based on the principle of electrical Joule heating. In the present work, middle frequency direct current (MFDC) was flowing through the powder compact, which was under mechanical pressure. The main parameters are the high electrical current......, up to 10 kA, and the low voltage, 1-2 V, resulting in heat generation in the powder. Figure 1 shows the experimental setup. The punches were made of a conductive material; namely a copper alloy. The die, which has to be electrically insulating, was made of alumina. The ESF process takes 3-4s...

strength and ductility of forged 1200 aluminum alloy reinforced

African Journals Online (AJOL)

eobe

duced cylindrical shape samples, which were homogenized at 420 ... and properties of deformed materials depend on other factors ... after the surfaces were ground with emery paper of ... Figure 2: Maximum elongation of forged and annealed.

Current steel forgings and their properties for steam generator of nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Tomoharu; Murai, Etsuo; Sato, Ikuo [Japan Steel Works Ltd., Muroran, Hokkaido (Japan). Muroran Plant; Suzuki, Kimiaki; Kusuhashi, Mikio; Tsukada, Hisashi [Japan Steel Works Ltd., Tokyo (Japan)

2001-06-01

On the steel forging (SF) elements for steam generator (SG) of the pressurized water type light water reactor (PWR), from a viewpoint of upgrading in their improvements of design and materials, here were described on three materials such as integrated steel forgings, high strength steel forgings, and vacuum carbon deoxidisation (VCD) steel forgings. On production of SG, by using the integrated SF, not only structural soundness of SG is upgraded, but also inspections containing inspections under production and usage become easier, to bring minimization of maintenance inspection and reduction of exposure under operation. And, in order to reduce weight of SG and upgrade seismic resistance, SA508, a Cl.3a high strength SF (620 MPa class in tensile strength) is used for some nuclear plants. Here were introduced material properties of this SF and described its chemical components and heat treatment condition. And, as a method to reduce macro- and micro-segregation of materials and to upgrade homogeneity of material property, a method combined deoxidisation of steel due to carbon monoxide reaction with crystal grain minimization due to addition of aluminum was investigated. In addition, properties of a low Si-SA508 Cl.3 steel using this method was compared with that of usual SA508 Cl.3 steel. (G.K.)

Evaluation of intergranular corrosion rate and microstructure of forged 316L round bar

International Nuclear Information System (INIS)

Lim, H. K.; Kim, Y. S.

2009-01-01

When austenitic stainless steels are heat treated in the range of 500∼850 .deg. C, the alloys are sensitized due to the formation of chromium carbide at grain boundaries and then intergranular corrosion occurs. This paper aims to evaluate the intergranular corrosion rate and microstructural change of forged 316L stainless steel. To analyze the microstructure by forging conditions, ferrite phase, sigma phase, intergranular precipitation were observed. In order to evaluate the intergranular corrosion rate. Huey test was performed by ASTM A262. On the base of microstructural observation, ferrite and sigma phases were not detected, and also intergranular precipitation was not revealed in optical microscopic observation. By ASTM A262 Practice A, step structure was shown in all forging conditions. Intergranular corrosion rate gradually increased by Huey test periods but average corrosion rate was under 0.03 mm/month

Evaluation of intergranular corrosion rate and microstructure of forged 316L round bar

Energy Technology Data Exchange (ETDEWEB)

Lim, H. K.; Kim, Y. S. [Andong National University, Andong (Korea, Republic of)

2009-12-15

When austenitic stainless steels are heat treated in the range of 500{approx}850 .deg. C, the alloys are sensitized due to the formation of chromium carbide at grain boundaries and then intergranular corrosion occurs. This paper aims to evaluate the intergranular corrosion rate and microstructural change of forged 316L stainless steel. To analyze the microstructure by forging conditions, ferrite phase, sigma phase, intergranular precipitation were observed. In order to evaluate the intergranular corrosion rate. Huey test was performed by ASTM A262. On the base of microstructural observation, ferrite and sigma phases were not detected, and also intergranular precipitation was not revealed in optical microscopic observation. By ASTM A262 Practice A, step structure was shown in all forging conditions. Intergranular corrosion rate gradually increased by Huey test periods but average corrosion rate was under 0.03 mm/month.

The effects of composition and thermal path on hot ductility of forging steels

Science.gov (United States)

Connolly, Brendan M.

This work examines the effects of composition and thermal path on the hot ductility of several forging steels with varied aluminum and nitrogen content. The primary mechanisms and controlling factors related to hot ductility are identified with a focus on the role of precipitates and segregation. The unique thermal paths and solidification structures of large cross-section forging ingots are discussed. Hot ductility testing is performed in a manner that approximates industrial conditions experienced by large cross-section forging ingots. A computer model for precipitation of aluminum nitride and vanadium nitride in austenite is presented. Industrial material is examined for comparison to experimental findings. It is found that increased aluminum and nitrogen content coarsens the as-solidified structure. The combined effects of microsegregation and uphill diffusion during deformation allow for carbide precipitation at prior austenite grain boundaries which reduces the hot ductility.

Forged HITEMAL: Al-based MMCs strengthened with nanometric thick Al{sub 2}O{sub 3} skeleton

Energy Technology Data Exchange (ETDEWEB)

Balog, Martin, E-mail: ummsbama@savba.sk [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Krizik, Peter; Nosko, Martin; Hajovska, Zuzana [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Victoria Castro Riglos, Maria [Centro Atómico Bariloche, Av. Bustillo 9.500, 8400 Bariloche, Río Negro (Argentina); Rajner, Walter [New Materials Development GmbH, Römerstrasse 28, 83410 Laufen, Leobendorf (Germany); Liu, De-Shin [National Chung Cheng University, 168 University Rd., Min-Hsiung, 62102 Chia-Yi, Taiwan (China); Simancik, Frantisek [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia)

2014-09-08

Bulk Al–Al{sub 2}O{sub 3} metal matrix composites (MMCs) named HITEMAL (high temperature aluminum) were fabricated in situ by forging compaction of five different types of gas-atomized commercial purity Al powders with a mean particle size in the range of 1–9 µm. As-forged HITEMAL consisted of (sub)micrometric Al grains (matrix) decorated with nanometric thick amorphous Al{sub 2}O{sub 3} (a-Al{sub 2}O{sub 3}) skeleton. Low-angle grain boundaries (LAGBs) free of Al{sub 2}O{sub 3} were located in the Al grain interior. The Al grain size and the portion of LAGBs increased with the increase in the relative powder surface area. As-forged HITEMAL shows excellent thermal stability up to 400 °C for 24 h. Annealing at temperatures ≥450 °C led to crystallization and morphological transformation from a-Al{sub 2}O{sub 3} skeleton to nanometric γ-Al{sub 2}O{sub 3} particles. Owing to the pinning effect of Al{sub 2}O{sub 3} phase, no Al grain growth took place during annealing up to 500 °C. HITEMAL showed attractive mechanical properties especially when tested at 300 °C (yield strength up to 220 MPa, Young's modulus up to 58 GPa). Despite the presence of a nearly continuous a-Al{sub 2}O{sub 3} skeleton along adjacent Al grains, forged HITEMAL materials had reasonable room temperature elongation of 7–26%. HITEMAL's elongation decreased as the Al grain size decreased and with increased testing temperature. The loss in elongation (uniform and total) was attributed to the inhomogeneous flow, which occurred due to high densities of high angle grain boundaries (dislocation sinks) and small content of LAGBs. The strength of HITEMAL stemmed from grain boundary mediated strengthening mechanisms. The results showed a positive deviation from the Hall–Petch plot, which is typical behavior of ultrafine-grained metals. Transformation of a-Al{sub 2}O{sub 3} skeleton to γ-Al{sub 2}O{sub 3} particles led to deterioration of the HITEMAL strength and Young's modulus.

Ultrasonic phased arrays for nondestructive inspection of forgings

International Nuclear Information System (INIS)

Wuestenberg, H.; Rotter, B.; Klanke, H.P.; Harbecke, D.

1993-01-01

Ultrasonic examinations on large forgings like rotor shafts for turbines or components for nuclear reactors are carried out at various manufacturing stages and during in-service inspections. During the manufacture, most of the inspections are carried out manually. Special in-service conditions, such as those at nuclear pressure vessels, have resulted in the development of mechanized scanning equipment. Ultrasonic probes have improved, and well-adapted sound fields and pulse shapes and based on special imaging procedures for the representation of the reportable reflectors have been applied. Since the geometry of many forgings requires the use of a multitude of angles for the inspections in-service and during manufacture, phased-array probes can be used successfully. The main advantages of the phased-array concept, e.g. the generation of a multitude of angles with the typical increase of redundancy in detection and quantitative evaluation and the possibility to produce pictures of defect situations, will be described in this contribution

Forging the links: a technology policy for Canada

Energy Technology Data Exchange (ETDEWEB)

1979-01-01

The Canadian economy is faced with a serious crisis which is manifest in high unemployment, persistent trade imbalances, and a falling currency. These immediate problems reflect a deeper crisis in the structure of Canadian industry, and in particular, manufacturing, which precedes the recent recession in the Western economies. High levels of technological and managerial truncation, and relative technological backwardness have placed Canadian industry at a particular disadvantage in light of the substantial changes taking place in world economies. The advanced industrial nations are moving into more technologically advanced forms of production - the new industrial revolution. This trend threatens to outpace the innovative capacity of Canadian industry to such an extent that its manufactured products will no longer be competitive with those of principal trading partners. Further, a number of developing countries with lower labour costs are moving into many of the conventional areas of industrial activity (e.g., assembly manufacturing operations), thus threatening to displace a significant number of Canada's traditional manufacturing activities through increased price competition. A rebuilding of Canada's industrial structure as well as improving its technological capability is required. Implementation of such an industrial strategy would require four initial policy objectives: 1) increase the demand for Canadian technology within the industrial system; 2) expand Canadian industry's potential to develop technology; 3) strengthen the capacity for the absorption of technology at the level of the firm; 4) increase the ability of Canadian firms to import technology under conditions favourable to Canada.

Stainless steel forgings for nuclear chemical plants

International Nuclear Information System (INIS)

1982-02-01

This Specification covers detailed requirements for the supply of austenitic stainless steel forgings used in radioactive and corrosive areas within the Nuclear Industry. With the exception of 316S51 the materials specified are all suitable for contact with nitric acid, 316S51 being included as suitable for use in contact with sodium and other alkali metals at elevated temperatures. (author)

The Investigations of Friction under Die Surface Vibration in Cold Forging Process

DEFF Research Database (Denmark)

Jinming, Sha

investigation, and the second stage is to design and manufacture a more practical tool system which can be used to forging some industrial components with larger capacity. The high performance and power piezoelectric actuator stack as the vibration source will be used for designing the vibration system in order...... to 50% with vibration being applied in forming process. Furthermore, by using finite element method, a series of the simulations of the cold forging process under die surface excitation have been implemented in order to further understand the influence of vibration on friction, especially the influence...

Design of a forging processing route for a gas turbine compressor disc in IMI 834

International Nuclear Information System (INIS)

Clark, G.S.

1993-01-01

The microstructure in all parts of a modern gas turbine compressor disc must be carefully controlled to give the optimum balance for resistance to creep and fatigue. This is particularly true for advanced titanium alloys such as IMI834. Dynamic recrystallisation during high temperature deformation and static recrystallisation and grain growth during heat treatment, all have a profound effect on the grain structure of the disc. These processes are affected by temperature, rate of deformation and various microstructural features. These may include the size and volume fraction of primary alpha particles and current beta grain size. The construction of a computer model to simulate the forging process must therefore take all these factors into account to fully simulate the mechanical and microstructural behaviour of the material during processing. This requires a complete characterisation of the material to formulate mechanical and microstructural constitutive equations for use in a visco-plastic finite element forging model. Similarly the forging equipment must be fully characterised so that forging processes can be accurately simulated. (orig.)

Near-liquidus forging, partial remelting and thixoforging of an AZ91D + Y magnesium alloy

International Nuclear Information System (INIS)

Zhao Zude; Chen Qiang; Hu Chuankai; Huang Shuhai; Wang Yuanqing

2009-01-01

A new route, near-liquidus forging plus partial remelting, has been developed for obtaining globular microstructures. Firstly, a material is formed by near-liquidus forging for obtaining a fine dendritic microstructure. Globular microstructure can be produced by reheating the material into the semi-solid temperature range for a period of time. In this paper, an AZ91D alloy with the addition of yttrium was prepared by near-liquidus forging. Microstructure evolution during partial remelting was studied at temperatures and for times. Tensile mechanical properties of thixoforged components were also determined. It is shown that the fine dendritic structure firstly evolves into a blocky structure during partial remelting. With prolonged holding time, the blocky structure disintegrates into polygonal solid particles. Prolonging time and increasing temperature promote a faster spheroidization. Good mechanical properties are obtained for the thixoforged AZ91D alloy with the addition of yttrium prepared by near-liquidus forging, with a yield strength of 160.9 MPa and a ultimate tensile strength of 301.7 MPa and a elongation to fracture of 9.734%.

Current forgings and their properties for steam generator of nuclear plant

International Nuclear Information System (INIS)

Tsukada, Hisashi; Suzuki, Komei; Kusuhashi, Mikio; Sato, Ikuo

1997-01-01

Current steel forgings for steam generator (SG) of PWR plant are reviewed in the aspect of design and material improvement. The following three items are introduced. The use of integral type steel forgings for the fabrication of steam generator enhances the structural integrity and makes easier fabrication and inspection including in-service inspection. The following examples of current integral type forgings developed by the Japan Steel Works, Ltd. (JSW) are introduced: (1) primary head integrated with nozzles, manways and supports; (2) steam drum head integrated with nozzle and handhole; (3) conical shell integrated with cylindrical sections and handholes. In order to decrease the weight of steam generator, the high strength materials such as SA508, Cl.3a steel have been adopted in some cases. The properties of this steel are introduced and the chemistry and heat treatment condition are discussed. As one of the methods to minimize the macro- and micro-segregations, the use of vacuum carbon deoxidation (VCD), i.e. deoxidization of steel by gaseous CO reaction, with addition of Al for grain refining was investigated. The properties of SA508, Cl.3 steels with Low Si content are compared with those of conventional one

Current forgings and their properties for steam generator of nuclear plant

Energy Technology Data Exchange (ETDEWEB)

Tsukada, Hisashi; Suzuki, Komei; Kusuhashi, Mikio; Sato, Ikuo [Japan Steel Works Ltd., Muroran (Japan)

1997-12-31

Current steel forgings for steam generator (SG) of PWR plant are reviewed in the aspect of design and material improvement. The following three items are introduced. The use of integral type steel forgings for the fabrication of steam generator enhances the structural integrity and makes easier fabrication and inspection including in-service inspection. The following examples of current integral type forgings developed by the Japan Steel Works, Ltd. (JSW) are introduced: (1) primary head integrated with nozzles, manways and supports; (2) steam drum head integrated with nozzle and handhole; (3) conical shell integrated with cylindrical sections and handholes. In order to decrease the weight of steam generator, the high strength materials such as SA508, Cl.3a steel have been adopted in some cases. The properties of this steel are introduced and the chemistry and heat treatment condition are discussed. As one of the methods to minimize the macro- and micro-segregations, the use of vacuum carbon deoxidation (VCD), i.e. deoxidization of steel by gaseous CO reaction, with addition of Al for grain refining was investigated. The properties of SA508, Cl.3 steels with Low Si content are compared with those of conventional one.

Void consolidation during open-die forging for ultralarge rotor shafts. (1. Formulation of void-closing behavior)

International Nuclear Information System (INIS)

Ono, Shin-ichi; Minami, Katsuyuki; Ochiai, Tomoyuki; Iwadate, Tadao; Nakata, Shin-ichi.

1995-01-01

Open-die forging experiments using different die geometries under hot isothermal conditions and three-dimensional simulations using rigid-plastic finite-element method were performed to formulate a void-closing behavior using only two factors; the integral of hydrostatic stress and the equivalent strain. First, upsetting, side-upsetting and V-shape die cogging of several cylinders with a spherical void at the center are carried out and the information on the void volume reduction is obtained. Seconds, the same forgings, but without voids is treated numerically and the development of stress and strain at the location of voids is investigated. Then, by combining these results, and using regression analysis, it is found that the void volume reduction is expressed as a polynomial function of the two factors. When the polynomial function is used, various forging methods can be evaluated quantitatively in terms of void-closing behavior. Therefore it is beneficial to optimize the forging process for a large rotor shaft. (author)

Deducing material quality in cast and hot-forged steels by new bending test

Science.gov (United States)

Valberg, Henry; Langøy, Morten; Nedreberg, Mette; Helvig, Torgeir

2017-10-01

A special bend test has been developed and applied for the purpose of characterization and comparison of the material ductility in crankpin steel discs manufactured by casting, or casting subsequently followed by hot open-die forging (ODF) or closed-die forging (CDF). The bending test specimen consists of a small rectangular plate of material with a round hole cut out in the middle. The "eye-shape" specimens were cut out from various positions either near to the surface of, or from the interior of the discs. The test method revealed differences in ductility for the investigated materials, and for different depth positions inside the discs. The roughening of the specimen surface on the top-side of the specimen bend also varied dependent on the processing method for the material. Current results show that this test method is useful for evaluation of material quality in differently processed material. Experimental bend test results are presented for differently processed variants of the same material, i.e., crankpin discs either made by solely casting or casting subsequently followed by hot working either by ODF or CDF.

The FORGE (Fate Of Repository Gases) pan European project

International Nuclear Information System (INIS)

Shaw, Richard

2010-01-01

Document available in extended abstract form only. Full text of publication follows: The multiple barrier concept is the cornerstone of all proposed schemes for underground disposal of radioactive wastes. The concept invokes a series of barriers, both engineered and natural, between the waste and the surface. Achieving this concept is the primary objective of all disposal programmes, from site appraisal and characterisation to repository design and construction. However, the performance of the repository as a whole (waste, buffer, engineering disturbed zone, host rock), and in particular its gas transport properties, are still poorly understood. Issues still to be adequately examined that relate to understanding basic processes include: dilational versus visco-capillary flow mechanisms; long-term integrity of seals, in particular gas flow along contacts; role of the EDZ as a conduit for preferential flow; laboratory to field up-scaling. Understanding gas generation and migration is thus vital in the quantitative assessment of repositories and is the focus of the research in this proposal for an integrated, multidisciplinary project. The FORGE project is a pan-European project with links to international radioactive waste management organisations, regulators and academia, specifically designed to tackle the key research issues associated with the generation and movement of repository gasses with partners from 24 organisations in 12 European countries. It is supported by funding under the European Commission FP7 Euratom programme and runs from 2009 to 2013. Of particular importance are the long-term performance of bentonite buffers, plastic clays, indurated mud-rocks and crystalline formations. Further experimental data are required to reduce uncertainty relating to the quantitative treatment of gas in performance assessment. FORGE will address these issues through a series of laboratory and field-scale experiments, including the development of new methods for up

76 FR 52313 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

Science.gov (United States)

2011-08-22

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-803] Heavy Forged Hand Tools (i.e... Administration, Department of Commerce. SUMMARY: As a result of the determinations by the Department of Commerce... on heavy forged hand tools (i.e., [[Page 52314

Family Health and Financial Literacy--Forging the Connection

Science.gov (United States)

Braun, Bonnie; Kim, Jinhee; Anderson, Elaine A.

2009-01-01

Families are at-risk of or experiencing a diminished quality of living and life in current economic times and difficult decisions are required. Health and financial literacy are the basis for wise personal and public decision making. Family and consumer sciences (FCS) professionals can forge connections between health and financial literacy to…

Forming of Hollow Shaft Forging From Titanium Alloy Ti6Al4V by Means of Rotary Compression

Directory of Open Access Journals (Sweden)

Tomczak J.

2015-04-01

Full Text Available This paper presents chosen results of theoretical-experimental works concerning forming of hollow shafts forgings from titanium alloys, which are applied in aviation industry. At the first stage of conducted analysis, the forging forming process was modeled by means of finite element method. Calculations were made using software Simufact Forming. On the basis of performed simulations optimal parameters of rotary compression process were determined. Next, experimental tests of forging forming in laboratory conditions were made. For the research needs, a forging aggregate, designed by the Authors, was used. Conducted research works confirmed the possibility of metal forming (by means of rotary compression of hollow shafts from hard workable titanium alloys. Numerous advantages of rotary compression process, make it attractive both for low series production (aircraft industry and for mass production (automotive industry.

An Assessment of the Ductile Fracture Behavior of Hot Isostatically Pressed and Forged 304L Stainless Steel

Science.gov (United States)

Cooper, A. J.; Smith, R. J.; Sherry, A. H.

2017-05-01

Type 300 austenitic stainless steel manufactured by hot isostatic pressing (HIP) has recently been shown to exhibit subtly different fracture behavior from that of equivalent graded forged steel, whereby the oxygen remaining in the component after HIP manifests itself in the austenite matrix as nonmetallic oxide inclusions. These inclusions facilitate fracture by acting as nucleation sites for the initiation, growth, and coalescence of microvoids in the plastically deforming austenite matrix. Here, we perform analyses based on the Rice-Tracey (RT) void growth model, supported by instrumented Charpy and J-integral fracture toughness testing at ambient temperature, to characterize the degree of void growth ahead of both a V-notch and crack in 304L stainless steel. We show that the hot isostatically pressed (HIP'd) 304L steel exhibits a lower critical void growth at the onset of fracture than that observed in forged 304L steel, which ultimately results in HIP'd steel exhibiting lower fracture toughness at initiation and impact toughness. Although the reduction in toughness of HIP'd steel is not detrimental to its use, due to the steel's sufficiently high toughness, the study does indicate that HIP'd and forged 304L steel behave as subtly different materials at a microstructural level with respect to their fracture behavior.

Fiscal 1999 achievement report on regional consortium research and development project. Regional consortium research and development of energy in its 1st year (Research and development of technologies for development and manufacture of magnesium alloys for cast and forged automotive parts); 1999 nendo jidosha muke chutanko buhin magnesium gokin no kaihatsu oyobi sono kako gijutsu no kenkyu kaihatsu seika hokokusho. 1

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

The research and development efforts aim to use more magnesium alloys of high performance aboard passenger cars. In the research and development of magnesium alloys for die-casting, studies are conducted about 14 kinds of alloys with their heat treatment properties improved, all based on an Mg-9%Zn-4.5%Al-0.6%Ca alloy which is expected to be excellent in resistance to heat and corrosion. In the development of forging-oriented high-strength magnesium alloys to be excellent in withstanding a hot working process, tractive characteristics superior to those of a forged 6061 aluminum material are obtained from an annealed ZK31 alloy. In the development of a high-performance heat-resistant magnesium alloy die-casting technology, it is found that an injection speed higher than that used for the existing alloys is necessary to achieve a product quality which is sound. This is true for all heat-resistant alloys except the ZAC series. Furthermore, technologies are developed which involve the forging of high-performance magnesium alloys, high-precision high-speed wet cutting, surface reforming of the environmentally friendly type, laser beam welding, etc. (NEDO)

Numerical optimization of die geometry in open die forging

DEFF Research Database (Denmark)

Christiansen, Peter; Hattel, Jesper Henri; Bay, Niels

2013-01-01

This paper deals with numerical optimization of open die forging of large metallic ingots made by casting implying risk of defects, e.g. central pores. Different material hardening properties and die geometries are combined in order to investigate, which geometry gives rise to maximum closure...

77 FR 39997 - Heavy Forged Hand Tools, Finished or Unfinished, With or Without Handles From the People's...

Science.gov (United States)

2012-07-06

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-803] Heavy Forged Hand Tools...) (Diamond Sawblades), the Department is notifying the public that the final judgment in this case is not in... review on heavy forged hand tools, finished or unfinished, with or without handles from the People's...

Standard specification for titanium and titanium alloy forgings

International Nuclear Information System (INIS)

Anon.

1975-01-01

Standards are given for the purchase, manufacture, product testing and certification, packaging, and marketing of annealed Ti and Ti-alloy forgings. The specifications apply to the following Ti alloys: 6Al-Ti-4V, 5Al-Ti-2.5 Sn, and Ti + Pd. Acceptable values for the chemical requirements, product analysis limits, and tensile requirements are tabulated

Final Technical Report: Intensive Quenching Technology for Heat Treating and Forging Industries

Energy Technology Data Exchange (ETDEWEB)

Aronov, Michael A.

2005-12-21

Intensive quenching (IQ) process is an alternative way of hardening (quenching) steel parts through the use of highly agitated water and then still air. It was developed by IQ Technologies, Inc. (IQT) of Akron, Ohio. While conventional quenching is usually performed in environmentally unfriendly oil or water/polymer solutions, the IQ process uses highly agitated environmentally friendly water or low concentration water/mineral salt solutions. The IQ method is characterized by extremely high cooling rates of steel parts. In contrast to conventional quenching, where parts cool down to the quenchant temperature and usually have tensile or neutral residual surface stresses at the end of quenching. The IQ process is interrupted when the part core is still hot and when there are maximum compressive stresses deep into the parts, thereby providing hard, ductile, better wear resistant parts. The project goal was to advance the patented IQ process from feasibility to commercialization in the heat-treating and forging industries to reduce significantly energy consumption and environmental impact, to increase productivity and to enhance economic competitiveness of these industries as well as Steel, Metal Casting and Mining industries. To introduce successfully the IQ technology in the U.S. metal working industry, the project team has completed the following work over the course of this project: A total of 33 manufacturers of steel products provided steel parts for IQ trails. IQT conducted IQ demonstrations for 34 different steel parts. Our customers tested intensively quenched parts in actual field conditions to evaluate the product service life and performance improvement. The data obtained from the field showed the following: Service life (number of holes punched) of cold-work punches (provided by EHT customer and made of S5 shock-resisting steel) was improved by two to eight times. Aluminum extrusion dies provided by GAM and made of hot work H-13 steel outperformed the

What history reveals about Forge River pollution on Long Island, New York's south shore.

Science.gov (United States)

Swanson, R Lawrence; Brownawell, B; Wilson, Robert E; O'Connell, Christine

2010-06-01

Fifty years ago, the Forge River and Moriches Bay, of Long Island's south shore lagoonal system, achieved notoriety when their polluted conditions were alluded to in a report of the US President's Science Advisory Committee (1965). The Woods Hole Oceanographic Institution investigated the bay throughout the 1950s, identifying duck farming as the cause of "objectionable", "highly contaminated" conditions of these waters. Much has changed: duck farming declined; the river was dredged to remove polluted sediments, improve navigation; and barrier island inlets stabilized. Yet, the river remains seasonally eutrophic. Why? This paper reviews what occurred in the Forge River watershed. While governments aggressively curtailed the impacts of duck pollution, they failed to manage development and sewage pollution. The Forge experience indicates that watershed management is a continuing governmental responsibility as development accelerates. Otherwise, we will always be looking for that instantaneous remediation that is usually not affordable and is socially contentious.

Open die forging of large shafts with porosity defects – physical and numerical modelling

DEFF Research Database (Denmark)

Christiansen, Peter; Hattel, Jesper Henri; Bay, Niels

2013-01-01

The aim and scope of this paper is centered to analyze the influence of the geometry of V-shaped dies on the closure of internal centerline porosity defects in ingots during multistep open-die forging. The investigation is performed with small scale physical models made from lead using V-shaped d......The aim and scope of this paper is centered to analyze the influence of the geometry of V-shaped dies on the closure of internal centerline porosity defects in ingots during multistep open-die forging. The investigation is performed with small scale physical models made from lead using V......-shaped dies with 90o and 120o and a reference pair of flat parallel platens. Holes drilled through the center of these preforms are produced to mimic centerline porosity in full scale cast ingots and intermediate rotation of the preforms replicate a multi-stage forging sequence under laboratory testing...

Multi-objective optimization of die geometry in ingot forging

DEFF Research Database (Denmark)

Christiansen, Peter; Martins, Paulo A.F.; Bay, Niels

2014-01-01

The soundness of an ingot after hot forging with different V-shaped lower dies is evaluated using finite element simulations.Two different modelling approaches that make use of uncoupled ductile damage and coupled ductile damage based on porousplasticity are employed. It is shown that the two...

Magnetic powder crack tests as a means of quality assurance in forged parts

International Nuclear Information System (INIS)

Deutsch, V.

1979-01-01

The magnetic powder process has been used for years for crack detection in forged parts, which are used as safety parts in car construction. The representation of the present state of technology appears useful, as terms and units have been redefined in DIN draft standards and guidelines, and because alternating field magnetisation has increasingly displaced earlier techniques. The correct choice of equipment, test materials and UV lamps, and the configuration of the working positions are discussed. As the complete automation of this test method is not possible at present, the organisation of the viewing process is of great importance. The comparison with other processes of non-destructive material testing proves the irreplaceability of the magnetic power crack testing at present. (orig.) [de

Mechanical properties of Zr-2.5Nb pressure tube material manufactured employing forging routes for PHWR700 - Part 1: tensile behavior

International Nuclear Information System (INIS)

Bind, A.K.; Singh, R.N.; Sunil, Saurav; Chakravartty, J.K.; Ghosh, Agnish; Dhandharia, Priyesh; More, Nitin S.; Vijayakumar, S.; Chhatre, A.G.

2012-01-01

Tensile properties of Zr-2.5Nb alloy tubes produced employing forging to break the cast structure were evaluated by carrying out uni-axial tension test at temperatures between 25 and 325 degC and under strain-rate of 1.075 x 10 -4 /s for both longitudinal and transverse specimens. Both strength and elongation values were comparable for the samples obtained from front and back end of the tube. Transverse samples showed higher strength and lower uniform elongation values as compared to longitudinal samples. The yield strength of double forged material at 25 degC is higher than the PHWR700 specification of a maximum value of 586 MPa. (author)

Analysis of residual stress in subsurface layers after precision hard machining of forging tools

Directory of Open Access Journals (Sweden)

Czan Andrej

2018-01-01

Full Text Available This paper is focused on analysis of residual stress of functional surfaces and subsurface layers created by precision technologies of hard machining for progressive constructional materials of forging tools. Methods of experiments are oriented on monitoring of residual stress in surface which is created by hard turning (roughing and finishing operations. Subsequently these surfaces were etched in thin layers by electro-chemical polishing. The residual stress was monitored in each etched layer. The measuring was executed by portable X-ray diffractometer for detection of residual stress and structural phases. The results significantly indicate rise and distribution of residual stress in surface and subsurface layers and their impact on functional properties of surface integrity.

Manufacturing of ultra-large diameter 20 MnMoNi 5 5 steel forgings for reactor pressure vessels and their properties

International Nuclear Information System (INIS)

Onodera, S.; Kawaguchi, S.; Tsukada, H.; Moritani, H.; Suzuki, K.; Sato, I.

1985-01-01

As the structural material for RPV typical of increased dimensions, as set of ultra-large diameter steel forgings for a PHWR RPV is presented as outlined below. (1) Material designation: 20 MnMoNi 5 5 (similar to SA508, Cl.3) (2) Size of the forgings: flanges, 8.440 mm OD, a weight of 238 tons for shell flange; shells and torus, 7,920 mm OD, with large height, cover dome, 6,800 mm OD in chord and 460 mm thick; blank before formed to dome is ca. 8,000 mm OD. (3) Chemical composition: particular effort was made for minimizing the tramp elements as P, S, As, Sn, Sb, Cu. (4) Manufacturing, key points: steel making - combined refining and degassing in ladle; ingot making - largest size ingots, including 570 ton and 500 ton ingots; forging - special ''outside-the-press'' forging and forming techniques; heat treatment - prevention of H 2 flaking in normalizing and tempering and handling of the extra-large forgings at water quenching. (5) Metallurgical properties: sufficiently uniform carbon distributions in the forgings; a lowest possible content of hydrogen, non-metallic inclusions and oxygen. Mechanical properties: uniformity in tensile and toughness properties; flaws - only limited number of spots of UT indications under 2 mm EFG (EFS). (orig.)

31 CFR 370.40 - Can I be held accountable if my negligence contributes to a forged signature?

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Can I be held accountable if my negligence contributes to a forged signature? 370.40 Section 370.40 Money and Finance: Treasury Regulations... if my negligence contributes to a forged signature? (a) General. If your failure to exercise ordinary...

A new Friction and Lubrication Test for Cold Forging

DEFF Research Database (Denmark)

Bay, Niels; Wibom, Ole; Aalborg Nielsen, J

1995-01-01

This paper presents a new friction and lubrication test for cold forging. The test allows controlled variation of the surface expansion in the range 0-2000%, the tool temperature in the range 20-270°C and the sliding length between 0 and infinite. Friction is decreasing with increasing temperature...

Transmission electron microscopy of Ti-12Mo-13Nb Alloy aged after heat forging; Microscopia eletronica de transmissao da liga Ti-12Mo-13Nb envelhecida apos forjamento a quente

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Nathalia Rodrigues [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil); Baldan, Renato [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia; Nunes, Carlos Angelo; Mei, Paulo Roberto [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil); Gabriel, Sinara Borborema [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

2014-06-15

Metastable β-Ti alloys possess mechanical properties, in particular a elastic modulus that depends not only on its composition but also the applied thermomechanical treatments. These alloys require high mechanical strength and a low Young’s modulus to avoid stress shielding. Preliminary studies on the development of Ti- 13Nb-12Mo alloy showed than the better properties were obtained at aged at 500 ° C / 24 h after cold forging , whose microstructure consisted of bimodal α phase in the β matrix. In this work, Ti-12Mo-13Nb alloy was heat forged and aged at 500 deg C for 24h and the microstructure was analyzed by employing X-ray diffraction and transmission electron microscopy. According to the results, while the cold forging resulted in bimodal α phase in the β matrix, hot forging resulted in a fine and homogeneous α phase in the β matrix. (author)

Investigating the effect of variable gutter technique as a novel method on vertical flow of material in closed die forging processes

Energy Technology Data Exchange (ETDEWEB)

Pourbashiri, M.; Sedighi, M. [Iran University, Tehran (Iran, Islamic Republic of)

2016-04-15

Recently, Variable gutter technique has been introduced as a novel method in order to reduce waste materials in closed-die forging processes. In this paper, the capability of this method is investigated for a family of forged parts that the vertical flow of material is the last stage of forming process. As a case study, using the variable gutter technique, the amount of waste material is decreased about 50% for a sample forged part with a local rising. The results of FVM simulations and experiments confirmed the effectiveness of the variable gutter technique in such forging processes. The vertical flow of material in the die cavity (h parameter), as a criterion, for different gutter width and thickness dimensions was examined by FVM simulations. The results shown that the gutter thickness has more effect on vertical flow of material than the gutter width. By decreasing the gutter thickness and increasing the gutter width, the amount of vertical flow of material is increased about 120% and 29%, respectively. Finally, A/H ratio (A = Max width of sectional area of a forged part, H = Max height of a forged part) is proposed as shape complexity factor of a forged part. The results of FVM simulations are indicated that for the ratio of A/H > 2, the variable gutter thickness technique is more effective and can be successfully used to reduce the amount of waste materials.

Application of directional solidification ingot (LSD) in forging of PWR reactor vessel heads

International Nuclear Information System (INIS)

Benhamou, C.; Poitrault, I.

1985-09-01

Creusot-Loire Industrie uses this type of ingot for manufacture of Framatome 1300 and 1450 MW 4-loop PWR reactor vessel heads. This type of ingot offers a number advantages: improved internal soundness; greater chemical, structural and mechanical homogeneity of the finished part; simplified forging process. After a brief description of the pouring and solidification processes, this paper presents an analysis of the results of examinations performed on the prototype forging, as well as review of results obtained during industrial fabrication of dished heads from LSD ingots. The advantages of the LSD ingot over conventional ingots are discussed in conclusion

Effect of nonmetallic inclusions on anisotropy of ductility in 35KhN3MFA steel forgings

International Nuclear Information System (INIS)

Shtremel', M.A.; Yavojskij, V.I.; Volkov, V.A.; Chursin, G.M.; Chukhlov, V.I.; Fetisov, G.I.; Mochalin, N.K.; Smol'yaninov, L.V.

1980-01-01

Characteristics of nonmetaltic inclusions and anizotropy of ductility and of impuct strength of forgings of the 35KhN3MFA steel are compared at different variants of melting and outer-furnace treatment. It is shown that method of melting rugulates anisotropy of ductility primarily through deformability of large inclusions during forging. Deformability of inclusions considerably changes due to introduction of silicocalcium in iron mold [ru

Development of SiC Nanoparticles and Second Phases Synergistically Reinforced Mg-Based Composites Processed by Multi-Pass Forging with Varying Temperatures

Directory of Open Access Journals (Sweden)

Kaibo Nie

2018-01-01

Full Text Available In this study, SiC nanoparticles were added into matrix alloy through a combination of semisolid stirring and ultrasonic vibration while dynamic precipitation of second phases was obtained through multi-pass forging with varying temperatures. During single-pass forging of the present composite, as the deformation temperature increased, the extent of recrystallization increased, and grains were refined due to the inhibition effect of the increasing amount of dispersed SiC nanoparticles. A small amount of twins within the SiC nanoparticle dense zone could be found while the precipitated phases of Mg17Al12 in long strips and deformation bands with high density dislocations were formed in the particle sparse zone after single-pass forging at 350 °C. This indicated that the particle sparse zone was mainly deformed by dislocation slip while the nanoparticle dense zone may have been deformed by twinning. The yield strength and ultimate tensile strength of the composites were gradually enhanced through increasing the single-pass forging temperature from 300 °C to 400 °C, which demonstrated that initial high forging temperature contributed to the improvement of the mechanical properties. During multi-pass forging with varying temperatures, the grain size of the composite was gradually decreased while the grain size distribution tended to be uniform with reducing the deformation temperature and extending the forging passes. In addition, the amount of precipitated second phases was significantly increased compared with that after multi-pass forging under a constant temperature. The improvement in the yield strength of the developed composite was related to grain refinement strengthening and Orowan strengthening resulting from synergistical effect of the externally applied SiC nanoparticles and internally precipitated second phases.

Modelling the void deformation and closure by hot forging of ingot castings

DEFF Research Database (Denmark)

Christiansen, Peter; Hattel, Jesper Henri; Kotas, Petr

2012-01-01

by mechanical deformation. The aim of this paper is to analyze numerically if and to what degree the voids areclosed by the forging. Using the commercial simulation software ABAQUS, both simplified model ingots and physically manufactured ingots containing prescribed void distributions are deformed and analyzed....... The analysis concernsboth the void density change and the location of the voids in the part after deformation. The latter can be important for the subsequent reliability of the parts, for instance regarding fatigue properties. The analysis incorporates the Gurson yield criterion for metals containing voids...... and focuses on how the voids deform depending on their size and distribution in the ingot as well ashow the forging forces are applied....

Backward can extrusion with conical,rotating punch as a cold forging tribology test

DEFF Research Database (Denmark)

Ceron, Ermanno; Bay, Niels; Tetsuo, A.

2011-01-01

with an analysis of the sliding velocity distribution along the punch nose. The latter is determined by FE analysis of the test. Results show friction stress for unalloyed low C-steel provided with different types of lubricants, e.g. phosphate coating plus soap, phosphate coating plus MoS2 and single bathe...... lubrication with PULS. The new test is so severe, that it is possible to break down the best lubrication systems for cold forging, such as phosphate coating plus soap and MoS2....

Army Combat Medic Resilience: The Process of Forging Loyalty.

Science.gov (United States)

Abraham, Preetha A; Russell, Dale W; Huffman, Sarah; Deuster, Patricia; Gibbons, Susanne W

2018-03-01

This study presents a grounded theory analysis of in-depth interviews of United States Army Combat Medics (CMs) who had served in Iraq and/or Afghanistan. The study explores how 17 CMs nominated by their peers as resilient cope with military stressors in order to identify the factors that enable them to thrive amidst harsh conditions. Four distinct categories of characteristics unique to this group emerged: (1) social bonding, (2) readiness, (3) dual loyalty as performance, and (4) leader by example. Forging loyalty underpins these characteristics and represents the main process used by resilient CMs and comprised three behavior patterns: (1) commitment to the family, (2) commitment to the military mission, and (3) commitment to their guiding religious and spiritual beliefs. Prominent behavioral tendencies of forging loyalty likely developed during childhood and re-enforced by families, friends, and other role models. Based on the findings, new training and education efforts should focus on developing positive emotional, environmental, and social resources to enhance the health and well-being of service members and their families.

Effects of boron additions and solutionizing treatments on microstructures and ductility of forged Ti–6Al–4V alloys

International Nuclear Information System (INIS)

Luan, J.H.; Jiao, Z.B.; Chen, G.; Liu, C.T.

2015-01-01

Highlights: • Proper boron additions and heat-treatments improve the ductility of Ti64 alloys. • Coarse TiB precipitates embrittle the Ti64 alloys causing ductility loss. • Modified Ti64 forged alloys with high strength and high ductility are developed. - Abstract: The effects of boron additions on the microstructure and mechanical properties of forged Ti–6Al–4V alloys in different heat-treatment conditions have been characterized by both experimental studies and thermodynamic calculations. The results indicate a combination of proper post-forging treatments and B additions are helpful for control of the prior-β grain size and the volume fraction of α phase, thereby tuning the ductility of the forged Ti–6Al–4V alloys. However, the B-containing alloys exhibit a significant drop in ductility if the solutionizing temperature is too high, and this embrittlement is mainly due to the coarsening of brittle TiB borides. The mechanism in this case is due to the cleavage fracture of TiB rather than its debonding with the matrix, as indicated by the observation of the aligned TiB borides on the matching areas of both halves of the fracture surfaces. Thus, the TiB size and orientation, the prior-β grain size, and the volume fraction of the α phase all play important roles in controlling the mechanical properties of the forged Ti–6Al–4V alloys. The current findings shed light on the composition–microstructure–ductility relationship in the forged Ti–6Al–4V alloys

Effects of boron additions and solutionizing treatments on microstructures and ductility of forged Ti–6Al–4V alloys

Energy Technology Data Exchange (ETDEWEB)

Luan, J.H.; Jiao, Z.B. [Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Hong Kong (China); Chen, G. [Engineering Research Center of Materials Behavior and Design, Ministry of Education, Nanjing University of Science and Technology, Nanjing 210094 (China); Liu, C.T., E-mail: chainliu@cityu.edu.hk [Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Hong Kong (China)

2015-03-05

Highlights: • Proper boron additions and heat-treatments improve the ductility of Ti64 alloys. • Coarse TiB precipitates embrittle the Ti64 alloys causing ductility loss. • Modified Ti64 forged alloys with high strength and high ductility are developed. - Abstract: The effects of boron additions on the microstructure and mechanical properties of forged Ti–6Al–4V alloys in different heat-treatment conditions have been characterized by both experimental studies and thermodynamic calculations. The results indicate a combination of proper post-forging treatments and B additions are helpful for control of the prior-β grain size and the volume fraction of α phase, thereby tuning the ductility of the forged Ti–6Al–4V alloys. However, the B-containing alloys exhibit a significant drop in ductility if the solutionizing temperature is too high, and this embrittlement is mainly due to the coarsening of brittle TiB borides. The mechanism in this case is due to the cleavage fracture of TiB rather than its debonding with the matrix, as indicated by the observation of the aligned TiB borides on the matching areas of both halves of the fracture surfaces. Thus, the TiB size and orientation, the prior-β grain size, and the volume fraction of the α phase all play important roles in controlling the mechanical properties of the forged Ti–6Al–4V alloys. The current findings shed light on the composition–microstructure–ductility relationship in the forged Ti–6Al–4V alloys.

The development of reactor vessel internal heavy forging for 1000 MW pressurized-water reactor nuclear power plant

International Nuclear Information System (INIS)

Zhang Zhifeng; Chen Yongbo; Ding Xiuping; Zhang Lingfang

2012-01-01

This Paper introduced the development of Reactor Vessel Internal (RVI) heavy forgings for 1000 MW Pressurized Water Reactor (PWR) nuclear power plant, analyzed the manufacture difficulties and technical countermeasures. The testing result of the product indicated that the performance of RVI heavy forgings manufactured by Shanghai Heavy Machinery Plant Ld. (SHMP) is outstanding and entirely satisfy the technical requirements for RVI product. (authors)

Multipass forging of Inconel 718 in the delta-Supersolvus domain: assessing and modeling microstructure evolution

Directory of Open Access Journals (Sweden)

Zouari Meriem

2014-01-01

Full Text Available This work is focused on the evolution of the microstructure of Inconel 718 during multi-pass forging processes. During the forming process, the material is subjected to several physical phenomena such as work-hardening, recovery, recrystallization and grain growth. In this work, transformation kinetics are modeled in the δ-Supersolvus domain (T>Tsolvus where the alloy is single-phase, all the alloying elements being dissolved into the FCC matrix. Torsion tests were used to simulate the forging process and recrystallization kinetics was modeled using a discontinuous dynamic recrystallization (DDRX two-site mean field model. The microstructure evolution under hot forging conditions is predicted in both dynamic and post-dynamic regimes based on the initial distribution of grain size and the evolution of dislocation density distribution during each step of the process. The model predicts recrystallization kinetics, recrystallized grain size distribution and stress–strain curve for different thermo-mechanical conditions and makes the connection between dynamic and post-dynamic regimes.

Effect of Friction on Barreling during cold Upset Forging of Aluminium 6082 Alloy Solid cylinders

Science.gov (United States)

Priyadarshini, Amrita; Kiran, C. P.; Suresh, K.

2018-03-01

Friction is one of the significant factors in forging operations since it affects metal flow in the die, forming load, strain distribution, tool and die life, surface quality of the product etc. In upset forging, the frictional forces at the die-workpiece interface oppose the outward flow of the material due to which the specimen develops a barrel shape. As a result, the deformation becomes non-uniform or inhomogeneous which is undesirable. Barreling can be reduced by applying effective lubricant on the surface of the platens. The objective of the present work is to study experimentally the effect of various frictional conditions (dry, grease, mineral oil) on barreling during upset forging of aluminum 6082 solid cylinders of different aspect ratio (length/diameter: 0.5, 0.75, 1). The friction coefficients are determined using the ring compression test. Curvature of barrel is determined based on the assumption that the curvature of the barrel follows the geometry of circular arc.

Effects of HIP and forging on fracture behaviour in cast iron with spheroidal vanadium carbides dispersed within martensitic-matrix microstructure

International Nuclear Information System (INIS)

Uematsu, Y.; Tokaji, K.; Nishigaki, K.; Okajima, D.; Ogasawara, M.

2010-01-01

The cast iron with spheroidal vanadium carbides dispersed within martensitic-matrix microstructure was developed as a die material due to its high hardness. In order to achieve high performances of dies, not only the hardness but also the mechanical properties such as fracture toughness and fatigue crack propagation (FCP) resistance should be improved. In this paper, hot isostatic pressing (HIP) or forging was applied to the cast iron to improve mechanical properties, and the fracture behaviour, such as flexural strength, fracture toughness and FCP, was studied. The average flexural strength was reduced by forging because of the enhanced notch sensitivity due to the increase in the hardness. The fracture toughness was not affected by HIP nor forging while its scatter was significantly reduced by both post-treatments. The intrinsic FCP resistance taking account of crack closure was the same regardless of the application of HIP or forging, indicating that a slight change in the microstructure resulting from both treatments and the presence of casting defects exerted little influence on FCP behaviour. It could be concluded that both HIP and forging could improve the hardness of the material, while fracture toughness and FCP resistance were maintained.

A multi-scale approach for high cycle anisotropic fatigue resistance: Application to forged components

International Nuclear Information System (INIS)

Milesi, M.; Chastel, Y.; Hachem, E.; Bernacki, M.; Loge, R.E.; Bouchard, P.O.

2010-01-01

Forged components exhibit good mechanical strength, particularly in terms of high cycle fatigue properties. This is due to the specific microstructure resulting from large plastic deformation as in a forging process. The goal of this study is to account for critical phenomena such as the anisotropy of the fatigue resistance in order to perform high cycle fatigue simulations on industrial forged components. Standard high cycle fatigue criteria usually give good results for isotropic behaviors but are not suitable for components with anisotropic features. The aim is to represent explicitly this anisotropy at a lower scale compared to the process scale and determined local coefficients needed to simulate a real case. We developed a multi-scale approach by considering the statistical morphology and mechanical characteristics of the microstructure to represent explicitly each element. From stochastic experimental data, realistic microstructures were reconstructed in order to perform high cycle fatigue simulations on it with different orientations. The meshing was improved by a local refinement of each interface and simulations were performed on each representative elementary volume. The local mechanical anisotropy is taken into account through the distribution of particles. Fatigue parameters identified at the microscale can then be used at the macroscale on the forged component. The linkage of these data and the process scale is the fiber vector and the deformation state, used to calculate global mechanical anisotropy. Numerical results reveal an expected behavior compared to experimental tendencies. We proved numerically the dependence of the anisotropy direction and the deformation state on the endurance limit evolution.

Forging of eccentric co-extruded Al-Mg compounds and analysis of the interface strength

International Nuclear Information System (INIS)

Förster, W; Binotsch, C; Awiszus, B; Lehmann, T; Müller, J; Kirbach, C; Stockmann, M; Ihlemann, J

2016-01-01

Within the subproject B3 of the Collaborative Research Center 692 it has been shown that Al-Mg compounds with a good bonding quality can be produced by hydrostatic coextrusion. During processing by forging, the aluminum sleeve is thinned in areas of high strains depending on the component geometry. To solve this problem an eccentric core arrangement during co-extrusion was investigated. Based on the results of FE-simulations, the experimental validation is presented in this work. Rods with an offset of 0.25, 0.5 and 0.75 mm were produced by eccentric hydrostatic co-extrusion. Ultrasonic testing was used to evaluate the bonding quality across the entire rods. For the forging investigations the basic process Rising was chosen. The still good bonding quality after forging was examined by dye penetrant testing and optical microscopy. For an optimal stress transfer between the materials across the entire component, a sufficient bonding between the materials is essential. To evaluate the interface strength, a special bending test was developed. For the conception of the bending specimens it was required to analyze the Rising specimens geometry. These analyses were performed using a reconstruction of the geometrical data based on computer tomography (CT) investigations. The comparison with the numerically deter-mined Rising specimen geometry shows good correlation. Parametric Finite Element Analyses of the bending test were used to develop the load case and the specimen geometry. By means of iterative adaption of load application, bearing and specimen geometry parameters, an advantageous stress state and experimentally applicable configuration were found. Based on this conception, the experimental setup was configured and bending tests were performed. The interface strength was deter-mined by the calculation of the maximum interlaminar interfacial tension stress using the experimental interface failure force and the bending FE model. (paper)

Environmentally Benign Lubricant Systems For Cold, Warm And Hot Forging

DEFF Research Database (Denmark)

Bay, Niels

2010-01-01

paper gives an overview of these efforts substituting environmentally hazardous lubricants in cold, warm and hot forging. The paper is an extract of the keynote paper [3] written by the author together with eight co-authors referring to collected papers and other information from more than 30 different...

On the quench sensitivity of 7010 aluminum alloy forgings in the overaged condition

Energy Technology Data Exchange (ETDEWEB)

Tiryakioğlu, Murat, E-mail: m.tiryakioglu@unf.edu [School of Engineering, University of North Florida, Jacksonville, FL 32224 (United States); Robinson, Jeremy S. [Department of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick, Limerick (Ireland); Eason, Paul D. [School of Engineering, University of North Florida, Jacksonville, FL 32224 (United States)

2014-11-17

The quench sensitivity of an overaged 7010 alloy forging was characterized by tensile and Vickers hardness tests, as well as scanning electron microscopy. Longitudinal tensile specimens, excised from a rectilinear open die forging were cooled from the solution treatment temperature following thirty-two different cooling paths including interrupted and delayed quenches. SEM analysis of the microstructure showed that quench precipitates were (i) Al{sub 2}CuMg (S) which nucleated heterogeneously on grain boundaries and (ii) Mg(Zn,Cu,Al){sub 2} (η) on grain boundaries, dispersoid bands, subgrain boundaries as well as in the aluminum matrix. The quench sensitivity of the alloy's yield strength and Vickers hardness was modeled simultaneously by quadruple-C curves, using an improved methodology for Quench Factor Analysis. The four C-curves used in the model represented loss of solute by (i) precipitation of S on grain boundaries, and precipitation of η (ii) on grain boundaries and dispersoid bands, (iii) on subgrain boundaries and (iv) in the matrix. The model yielded coefficient of determination (R{sup 2}) values of 0.967 and 0.974 for yield strength and Vickers hardness, respectively. The model and the implications of the results are discussed in this paper.

A friction model for cold forging of aluminum, steel and stainless steel provided with conversion coating and solid film lubricant

DEFF Research Database (Denmark)

Bay, Niels; Eriksen, Morten; Tan, Xincai

2011-01-01

Adopting a simulative tribology test system for cold forging the friction stress for aluminum, steel and stainless steel provided with typical lubricants for cold forging has been determined for varying normal pressure, surface expansion, sliding length and tool/work piece interface temperature...

Evaluation of Microstructural and Mechanical Property of Medium-sized HT9 Cladding Forged Material for Sodium-cooled Fast Reactor

International Nuclear Information System (INIS)

Kim, Jun Hwan; Lee, Kang Soo; Kim, Sung Ho; Lee, Chan Bock

2012-01-01

Microstructural and mechanical property were evaluated at the medium-sized HT9 (12Cr-1MoWV) forged steel which was considered as primary candidate for the fuel cladding in sodium-cooled fast reactor (SFR). Material was forged at 1170 degrees C after the induction melting to make round bar as 160 mm diameter, 7000 mm length then the radial distribution of microstructure as well as microhardness was evaluated. The results showed that overall microstructure exhibited as ferrite-martensite structure, where small amount (2-3%) of delta ferrite was formed throughout the specimen and maximum 15% of transformed ferrite was formed at the center, where it gradually decreased toward the radial direction. Sensitivity analysis of the cooling curve and Time-Temperature-Transformation (TTT) diagram revealed that formation of transformed ferrite could be avoided when the diameter was decreased down to 120 mm.

Follow-up of hearing thresholds among forge hammering workers

Energy Technology Data Exchange (ETDEWEB)

Kamal, A.A.; Mikael, R.A.; Faris, R. (Ain Shams Univ., Abbasia, Cairo (Egypt))

1989-01-01

Hearing threshold was reexamined in a group of forge hammering workers investigated 8 years ago with consideration of the age effect and of auditory symptoms. Workers were exposed to impact noise that ranged from 112 to 139 dB(A)--at an irregular rate of 20 to 50 drop/minute--and a continuous background noise that ranged from 90 to 94 dB(A). Similar to what was observed 8 years ago, the present permanent threshold shift (PTS) showed a maximum notch at the frequency of 6 kHz and considerable elevations at the frequencies of 0.25-1 kHz. The age-corrected PTS and the postexposure hearing threshold were significantly higher than the corresponding previous values at the frequencies 0.25, 0.5, 1, and 8 kHz only. The rise was more evident at the low than at the high frequencies. Temporary threshold shift (TTS) values were significantly less than those 8 years ago. Contrary to the previous TTS, the present TTS were higher at low than at high frequencies. Although progression of PTS at the frequencies 0.25 and 0.5 kHz was continuous throughout the observed durations of exposure, progression at higher frequencies occurred essentially in the first 10 to 15 years of exposure. Thereafter, it followed a much slower rate. Tinnitus was significantly associated with difficulty in hearing the human voice and with elevation of PTS at all the tested frequencies, while acoustic after-image was significantly associated with increment of PTS at the frequencies 0.25-2 kHz. No relation between PTS and smoking was found. PTS at low frequencies may provide an indication of progression of hearing damage when the sensitivity at 6 and 4 kHz diminishes after prolonged years of exposure. Tinnitus and acoustic after-image are related to the auditory effect of forge hammering noise.

Ageing of forged superaustenitic stainless steel: Precipitate phases and mechanical properties

Energy Technology Data Exchange (ETDEWEB)

Anburaj, J., E-mail: janburaj@gmail.com [Department of Metallurgical Engineering, PSG College of Technology, Coimbatore 641 004 (India); Nazirudeen, S.S. Mohamed; Narayanan, R.; Anandavel, B.; Chandrasekar, A. [Department of Metallurgical Engineering, PSG College of Technology, Coimbatore 641 004 (India)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Solutionizing of 1250 Degree-Sign C and ageing of 500-1000 Degree-Sign C was done for hot forged SASS. Black-Right-Pointing-Pointer Strength and toughness increased by 25% on hot forged than the cast SASS. Black-Right-Pointing-Pointer Amounts of precipitates after ageing were evaluated by thermo-calc. Black-Right-Pointing-Pointer Sigma forms from chi at 900 Degree-Sign C and contains constant Cr and Mo contents, unlike chi. Black-Right-Pointing-Pointer Sigma is incoherent, contains high Mo and causes low toughness at 900 Degree-Sign C. - Abstract: Cast superaustenitic stainless steel (SASS), of composition 19 wt% Cr, 20 wt% Ni, 7.5 wt% Mo and 0.37 wt% N, is hot forged at 1200 Degree-Sign C. The forging was then solutionized at 1250 Degree-Sign C and aged for 1 h and 10 h at different temperatures in the range of 500-1000 Degree-Sign C. Effect of these treatments on (i) hardness and (ii) fracture toughness based on impact energy is reported. Chi is formed from low temperatures up to 800 Degree-Sign C, and sigma at temperatures above 900 Degree-Sign C. A model is proposed to illustrate the dissolution of chi and sigma in austenite at elevated temperatures. Compared with chi, sigma contains more Mo. Toughness decreased with increasing amounts of chi and sigma precipitates. However, in the temperature range of 850-950 Degree-Sign C, low toughness was observed for relatively a short ageing time, although virtually the volume of sigma phase is very low. This is attributed to the presence of incoherent sigma in austenite matrix. Fractographs of the impact-tested samples indicated an increased tendency for brittle fracture with increasing ageing temperatures (increase in sigma content). Thermodynamic calculations substantiated (i) EDS results of composition of secondary phases present in the aged SASS and (ii) the proposed model. From these studies it is concluded that sigma is enriched in Mo at 900 Degree-Sign C and can be as

Political Show-Technology in the Post-Soviet Space

Directory of Open Access Journals (Sweden)

O. E. Grishin

2015-01-01

Full Text Available In the modern political process of Russia actively used technology show. With their help, political actors can influence public opinion and shape the public interest in certain issues. In Russia, these technologies are relevant, and are especially well developed. The pressing of the problem is due to a new round of information war on the territory of Ukraine. Inclusion in the information space, and discuss the pressing issues of modern Ukraine by media people such as C. Shuster and V. Solovyov, suggests that the political show has entertainment figures, actuality, the ambiguity of the proposed conclusions. At the same time it becomes part of the information war and political reality of the normal state.

Multi-field coupling finite element analysis for determining the influence of temperature field on die service life during precision-forming process of steel synchronizer ring

International Nuclear Information System (INIS)

Zhao, Jun; Luo, Shan-Ming; Li, Feng-Qiang; Xu, Chen-Bing

2017-01-01

Failure analysis shows that increased die temperature caused by severe plastic deformation of material and heat conduction between hot billet and cavity significantly affects the distortion of gear cavity in steel synchronizer ring forging process. The forging process of steel synchronizer ring and die temperature distribution under different forging conditions are analyzed through finite element method. Simulation results show that severe plastic deformation occurs in the gear cavity. The improvement of lubrication condition results in decreased die temperature. When the initial billet temperature is high, the die temperature is also high. Increasing forging speed in a certain range facilitates the die temperature decrease. The distribution of die temperature in synthetic forming technology is more reasonable than that of one step forging. The synthetic forming technology is adopted in production to reduce the effects of severe plastic deformation caused by die temperature. The ejection mechanism and control system of the double disc friction press are improved to reduce the contact time between the hot billet and cavity. Experimental results show that synthetic forming technology is reasonable, and that the die service life is prolonged.

Multi-field coupling finite element analysis for determining the influence of temperature field on die service life during precision-forming process of steel synchronizer ring

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jun; Luo, Shan-Ming; Li, Feng-Qiang; Xu, Chen-Bing [Xiamen University of Technology, Xiamen (China)

2017-07-15

Failure analysis shows that increased die temperature caused by severe plastic deformation of material and heat conduction between hot billet and cavity significantly affects the distortion of gear cavity in steel synchronizer ring forging process. The forging process of steel synchronizer ring and die temperature distribution under different forging conditions are analyzed through finite element method. Simulation results show that severe plastic deformation occurs in the gear cavity. The improvement of lubrication condition results in decreased die temperature. When the initial billet temperature is high, the die temperature is also high. Increasing forging speed in a certain range facilitates the die temperature decrease. The distribution of die temperature in synthetic forming technology is more reasonable than that of one step forging. The synthetic forming technology is adopted in production to reduce the effects of severe plastic deformation caused by die temperature. The ejection mechanism and control system of the double disc friction press are improved to reduce the contact time between the hot billet and cavity. Experimental results show that synthetic forming technology is reasonable, and that the die service life is prolonged.

Wear Improvement of Tools in the Cold Forging Process for Long Hex Flange Nuts.

Science.gov (United States)

Hsia, Shao-Yi; Shih, Po-Yueh

2015-09-25

Cold forging has played a critical role in fasteners and has been widely used in automotive production, manufacturing, aviation and 3C (Computer, Communication, and Consumer electronics). Despite its extensive use in fastener forming and die design, operator experience and trial and error make it subjective and unreliable owing to the difficulty of controlling the development schedule. This study used finite element analysis to establish and simulate wear in automotive repair fastener manufacturing dies based on actual process conditions. The places on a die that wore most quickly were forecast, with the stress levels obtained being substituted into the Archard equation to calculate die wear. A 19.87% improvement in wear optimization occurred by applying the Taguchi quality method to the new design. Additionally, a comparison of actual manufacturing data to simulations revealed a nut forging size error within 2%, thereby demonstrating the accuracy of this theoretical analysis. Finally, SEM micrographs of the worn surfaces on the upper punch indicate that the primary wear mechanism on the cold forging die for long hex flange nuts was adhesive wear. The results can simplify the development schedule, reduce the number of trials and further enhance production quality and die life.

Anisotropy effects during dwell-fatigue caused by δ-phase orientation in forged Inconel 718

Energy Technology Data Exchange (ETDEWEB)

Saarimäki, Jonas, E-mail: jonas.saarimaki@liu.se [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden); Colliander, Magnus Hörnqvist [Department of Applied Physics, Chalmers University of Technology, SE-41296 Göteborg (Sweden); GKN Aerospace Engine Systems, R& T Centre, SE-46181 Trollhättan (Sweden); Moverare, Johan J. [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden)

2017-04-24

Inconel 718 is a commonly used superalloy for turbine discs in the gas turbine industry. Turbine discs are often subjected to dwell-fatigue as a result of long constant load cycles. The effect of anisotropy on dwell-fatigue cracking in forged turbine discs have not yet been thoroughly investigated. Crack propagation behaviour was characterised using compact tension (CT) samples cut in different orientations from a real turbine disc forging. Samples were also cut in two different thicknesses in order to investigate the influence of plane strain and plane stress condition on the crack propagation rates. The samples were subjected to dwell-fatigue tests at 550 °C with 90 s or 2160 s dwell-times at maximum load. Microstructure characterisation was done using scanning electron microscopy (SEM) techniques such as electron channelling contrast imaging (ECCI), electron backscatter diffraction (EBSD), and light optical microscopy (LOM). The forged alloy exhibits strong anisotropic behaviour caused by the non-random δ-phase orientation. When δ-phases were oriented perpendicular compared to parallel to the loading direction, the crack growth rates were approximately ten times faster. Crack growth occurred preferably in the interface between the γ-matrix and the δ-phase.

76 FR 8773 - Forged Stainless Steel Flanges From India and Taiwan

Science.gov (United States)

2011-02-15

... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 731-TA-639 and 640 (Third Review)] Forged Stainless Steel Flanges From India and Taiwan AGENCY: United States International Trade Commission. ACTION... Taiwan would be likely to lead to continuation or recurrence of material injury. On January 31, 2011, the...

A Probabilistic Analysis of the Nxt Forging Algorithm

Directory of Open Access Journals (Sweden)

Serguei Popov

2016-12-01

Full Text Available We discuss the forging algorithm of Nxt from a probabilistic point of view, and obtain explicit formulas and estimates for several important quantities, such as the probability that an account generates a block, the length of the longest sequence of consecutive blocks generated by one account, and the probability that one concurrent blockchain wins over an- other one. Also, we discuss some attack vectors related to splitting an account into many smaller ones.

Forging of cast Mg-3Sn-2Ca-0.4Al-0.4Si magnesium alloy using processing map

International Nuclear Information System (INIS)

Rao, K. P.; Suresh, K.; Prasad, Y. V. R. K.; Hort, N.; Kainer, K. U.

2016-01-01

Mg-3Sn-2Ca (TX32) alloy has good creep resistance but limited workability. Minor amounts of Al and Si have been added to TX32 for improving its hot workability. The processing map for the TX32-0.4Al-0.4Si alloy exhibited two workability domains in the temperature and strain rate ranges: (1) 310-415.deg.C/0.0003-0.003 s-1 and (2) 430-500.deg.C/0.003-3 s-1. The alloy exhibited flow instability at temperatures < 350.deg.C at strain rates > 0.01 s-1. The alloy has been forged to produce a cup shape component to validate these findings of processing map. Finite-element (FE) simulation has been performed for obtaining the local variations of strain and strain rate within the forging. The microstructures of the forged components under the optimal domain conditions revealed dynamically recrystallized grains, and those forged in the flow instability regime have fractured and exhibited flow localization bands and cracks. The experimental load stroke curves correlated well with those obtained by FE simulation.

Forging of cast Mg-3Sn-2Ca-0.4Al-0.4Si magnesium alloy using processing map

Energy Technology Data Exchange (ETDEWEB)

Rao, K. P.; Suresh, K.; Prasad, Y. V. R. K. [University of Hong Kong, Hong Kong (China); Hort, N.; Kainer, K. U. [Magnesium Innovation Centre, Geesthacht (Germany)

2016-06-15

Mg-3Sn-2Ca (TX32) alloy has good creep resistance but limited workability. Minor amounts of Al and Si have been added to TX32 for improving its hot workability. The processing map for the TX32-0.4Al-0.4Si alloy exhibited two workability domains in the temperature and strain rate ranges: (1) 310-415.deg.C/0.0003-0.003 s-1 and (2) 430-500.deg.C/0.003-3 s-1. The alloy exhibited flow instability at temperatures < 350.deg.C at strain rates > 0.01 s-1. The alloy has been forged to produce a cup shape component to validate these findings of processing map. Finite-element (FE) simulation has been performed for obtaining the local variations of strain and strain rate within the forging. The microstructures of the forged components under the optimal domain conditions revealed dynamically recrystallized grains, and those forged in the flow instability regime have fractured and exhibited flow localization bands and cracks. The experimental load stroke curves correlated well with those obtained by FE simulation.

The Simulation and Analysis of the Closed Die Hot Forging Process by A Computer Simulation Method

Directory of Open Access Journals (Sweden)

Dipakkumar Gohil

2012-06-01

Full Text Available The objective of this research work is to study the variation of various parameters such as stress, strain, temperature, force, etc. during the closed die hot forging process. A computer simulation modeling approach has been adopted to transform the theoretical aspects in to a computer algorithm which would be used to simulate and analyze the closed die hot forging process. For the purpose of process study, the entire deformation process has been divided in to finite number of steps appropriately and then the output values have been computed at each deformation step. The results of simulation have been graphically represented and suitable corrective measures are also recommended, if the simulation results do not agree with the theoretical values. This computer simulation approach would significantly improve the productivity and reduce the energy consumption of the overall process for the components which are manufactured by the closed die forging process and contribute towards the efforts in reducing the global warming.

Forging Consensus for Implementing Youth Socialization Policy in Northwest China

Science.gov (United States)

Fairbrother, Gregory P.

2011-01-01

The goal of this article is to examine how the provincial education media in China play a role of forging consensus among local actors responsible for the implementation of new centrally-promulgated youth socialization policy. In doing so, it also explores the tension among three of the Chinese state's claims to legitimacy: economic development,…

Large forging manufacturing process

Science.gov (United States)

Thamboo, Samuel V.; Yang, Ling

2002-01-01

A process for forging large components of Alloy 718 material so that the components do not exhibit abnormal grain growth includes the steps of: a) providing a billet with an average grain size between ASTM 0 and ASTM 3; b) heating the billet to a temperature of between 1750.degree. F. and 1800.degree. F.; c) upsetting the billet to obtain a component part with a minimum strain of 0.125 in at least selected areas of the part; d) reheating the component part to a temperature between 1750.degree. F. and 1800.degree. F.; e) upsetting the component part to a final configuration such that said selected areas receive no strains between 0.01 and 0.125; f) solution treating the component part at a temperature of between 1725.degree. F. and 1750.degree. F.; and g) aging the component part over predetermined times at different temperatures. A modified process achieves abnormal grain growth in selected areas of a component where desirable.

Fatigue properties of high-strength materials used in cold-forging tools

DEFF Research Database (Denmark)

Brøndsted, P.; Skov-Hansen, P.

1998-01-01

In the present work classical analytical models are used to describe the static stress–strain curves, low-cycle fatigue properties and fatigue crack growth behaviour of high-strength materials for use in tools for metal-forming processes such as cold forging and extrusion. The paper describes the...

75 FR 67110 - Forged Stainless Steel Flanges From India and Taiwan

Science.gov (United States)

2010-11-01

... Stainless Steel Flanges From India and Taiwan AGENCY: United States International Trade Commission. ACTION... India and Taiwan. SUMMARY: The Commission hereby gives notice that it has instituted reviews pursuant to... the antidumping duty orders on forged stainless steel flanges from India and Taiwan would be likely to...

Medium carbon vanadium steels for closed die forging; Acos de medio carbono microligados ao vanadio para forjaria em matriz fechada

Energy Technology Data Exchange (ETDEWEB)

Jeszensky, Gabor; Plaut, Ronald Lesley

1994-12-31

This work analyses the medium carbon micro alloyed vanadium potential for closed die forged production. The steels reach the mechanical resistance requests during cooling after forging, eliminating the subsequent thermal treatment. Those steels also present good fatigue resistance and machinability. The industrial scale experiments are also reported 16 refs., 21 figs.

Optimum back-pressure forging using servo die cushion

OpenAIRE

Kawamoto, Kiichiro; Yoneyama, Takeshi; Okada, Masato; Kitayama, Satoshi; Chikahisa, Junpei

2014-01-01

This study focused on utilizing a servo die cushion (in conjunction with a servo press) as a "back-pressure load generator," to determine its effect on shape accuracy of the formed part and total forming load in forward extrusion during cold forging. The effect of back-pressure load application was confirmed in experiments, and the optimum setting pattern of back-pressure load was considered to minimize both shape accuracy of the formed part and back-pressure energy, which was representative ...

Best possible heat treatment of steel SA 336 F22 for the production of forged shells with heavy walls

International Nuclear Information System (INIS)

Badeau, J.P.; Poitrault, I.S.; De Badereau, A.; Blondeau, R.P.

1986-01-01

The manufacturing of thick-wall components, such as shells, for petrochemical reactors normally requires the 2.25Cr-1Mo(SA 336 F22) steel. This paper deals with: 1. Experienced difficulties in producing thick-wall forgings up to a thickness of 500 mm with standard 2.25Cr-1Mo steel. 2. The solutions offered by Le Creusot Heavy Forge. The studies discussed are: (1) the effect of the structure; (2) the effect of the chemical composition on hardenability and temper embrittlement in steel making; and (3) the effect of austenitization conditions. Some examples concerning industrial forgings are presented, among them: 1. The manufacturing of shells for the petrochemical industry. 2. A thick-wall shell from a 146-metric ton hollow ingot

Hot Deformation Behavior and Pulse Current Auxiliary Isothermal Forging of Hot Pressing Sintering TiAl Based Alloys.

Science.gov (United States)

Shi, Chengcheng; Jiang, Shaosong; Zhang, Kaifeng

2017-12-16

This paper focuses on the fabrication of as-forged Ti46.5Al2Cr1.8Nb-(W, B) alloy via pulse current auxiliary isothermal forging (PCIF). The starting material composed of near gamma (NG) microstructure was fabricated by adopting pre-alloyed powders via hot pressing sintering (HPS) at 1300 °C. Isothermal compression tests were conducted at a strain rate range of 0.001-0.1 s -1 and a temperature range of 1125-1275 °C to establish the constitutive model and processing map. The optimal hot deformation parameters were successfully determined (in a strain rate range of 10 -3 -2.5 × 10 -3 s -1 and temperature range of 1130-1180 °C) based on the hot processing map and microstructure observation. Accordingly, an as-forged TiAl based alloy without cracks was successfully fabricated by PCIF processing at 1175 °C with a nominal strain rate of 10 -3 s -1 . Microstructure observation indicated that complete dynamic recrystallization (DRX) and phase transformation of γ→α₂ occurred during the PCIF process. The elongation of as-forged alloy was 136%, possessing a good secondary hot workability, while the sintered alloy was only 66% when tested at 900 °C with a strain rate of 2 × 10 -4 s -1 .

Engine piston assembly and forged piston member therefor having a cooling recess

Energy Technology Data Exchange (ETDEWEB)

Cooper, B.C.; Erickson, K.L.; Green, J.A.; Nyez, D.S.

1989-09-19

This patent describes a forged steel piston member for reciprocating movement in an engine. It comprises: an upper portion of substantially cylindrical shape and having a central axis, a top surface, a tubular wall depending from the top surface and having a peripheral groove adapted to receive a sealing ring, a lower end surface, and an inwardly facing wall surface extending upwardly from the lower end surface. The upper portion further includes an outwardly facing wall surface spaced radially inwardly from the inwardly facing wall surface and a downwardly facing transition portion blendingly associated with the inwardly and outwardly facing wall surfaces to collectively define an annular cooling recess, the transition portion being elevational spaced a relatively short distance from the top surface; and the inwardly facing wall surface being a machined surface of revolution about the central axis integral or one-piece forging.

FE-simulation of hot forging with an integrated heat treatment with the objective of residual stress prediction

Science.gov (United States)

Behrens, Bernd-Arno; Chugreeva, Anna; Chugreev, Alexander

2018-05-01

Hot forming as a coupled thermo-mechanical process comprises numerous material phenomena with a corresponding impact on the material behavior during and after the forming process as well as on the final component performance. In this context, a realistic FE-simulation requires reliable mathematical models as well as detailed thermo-mechanical material data. This paper presents experimental and numerical results focused on the FE-based simulation of a hot forging process with a subsequent heat treatment step aiming at the prediction of the final mechanical properties and residual stress state in the forged component made of low alloy CrMo-steel DIN 42CrMo4. For this purpose, hot forging experiments of connecting rod geometry with a corresponding metallographic analysis and x-ray residual stress measurements have been carried out. For the coupled thermo-mechanical-metallurgical FE-simulations, a special user-defined material model based on the additive strain decomposition method and implemented in Simufact Forming via MSC.Marc solver features has been used.

On the Effects of Hot Forging and Hot Rolling on the Microstructural Development and Mechanical Response of a Biocompatible Ti Alloy

Science.gov (United States)

Okazaki, Yoshimitsu

2012-01-01

Zr, Nb, and Ta as alloying elements for Ti alloys are important for attaining superior corrosion resistance and biocompatibility in the long term. However, note that the addition of excess Nb and Ta to Ti alloys leads to higher manufacturing cost. To develop low-cost manufacturing processes, the effects of hot-forging and continuous-hot-rolling conditions on the microstructure, mechanical properties, hot forgeability, and fatigue strength of Ti-15Zr-4Nb-4Ta alloy were investigated. The temperature dependences with a temperature difference (ΔT) from β-transus temperature (Tβ) for the volume fraction of the α- and β-phases were almost the same for both Ti-15Zr-4Nb-4Ta and Ti-6Al-4V alloys. In the α-β-forged Ti-15Zr-4Nb-4Ta alloy, a fine granular α-phase structure containing a fine granular β-phase at grain boundaries of an equiaxed α-phase was observed. The Ti-15Zr-4Nb-4Ta alloy billet forged at Tβ-(30 to 50) °C exhibited high strength and excellent ductility. The effects of forging ratio on mechanical strength and ductility were small at a forging ratio of more than 3. The maximum strength (σmax) markedly increased with decreasing testing temperature below Tβ. The reduction in area (R.A.) value slowly decreased with decreasing testing temperature below Tβ. The temperature dependences of σmax for the Ti-15Zr-4Nb-4Ta and Ti-6Al-4V alloys show the same tendency and might be caused by the temperature difference (ΔT) from Tβ. It was clarified that Ti-15Zr-4Nb-4Ta alloy could be manufactured using the same manufacturing process as for previously approved Ti-6Al-4V alloy, taking into account the difference (ΔT) between Tβ and heat treatment temperature. Also, the manufacturing equivalency of Ti-15Zr-4Nb-4Ta alloy to obtain marketing approval of implants was established. Thus, it was concluded that continuous hot rolling is useful for manufacturing α-β-type Ti alloy.

Study on antioxidant experiment on forged steel tube sheet and tube hole for steam generator

International Nuclear Information System (INIS)

Zong Hai; Wang Detai; Ding Yang

2012-01-01

Antioxidant experiment on forged steel tube sheet and tube hole for steam generator was studied and the influence of different simulated heat treatments on the antioxidant performance of tube sheet and tube hole was made. The influence of different antioxidant methods on the size of tube hole was drawn. Furthermore, the change of size and weight of 18MnD5 forged steel tube sheet on the condition of different simulated heat treatments was also studied. The analytical results have proved reference information for the use of 18MnD5 material and for key processes of processing tube hole and wearing and expanding U-style tube. (authors)

Social Work and Engineering Collaboration: Forging Innovative Global Community Development Education

Science.gov (United States)

Gilbert, Dorie J.

2014-01-01

Interdisciplinary programs in schools of social work are growing in scope and number. This article reports on collaboration between a school of social work and a school of engineering, which is forging a new area of interdisciplinary education. The program engages social work students working alongside engineering students in a team approach to…

Simulation and experimental verification of the filling process of semi-solid die forging for cup shell

OpenAIRE

Jianbo TAN; Zichao WANG; Dongxu WANG

2015-01-01

The filling mold process of semi-solid alloy blank influences severely the forming and properties of finished piece. In this paper, DEFORM is applied to simulate the process of cup-type 6061 alloy die forging casting. The influences of the temperature of semi-solid alloy blank, preheating temperature, and downward press speed of pressure head on process of mold filling and velocity field are investigated. The results show that the mold filling of semi-solid alloy paste smoothly fills along th...

Forgings made of austenitic chromium-nickel steels for the low temperature range

International Nuclear Information System (INIS)

Gruendler, O.; Schwarz, W.; Koren, M.

1981-01-01

The authors discuss the low temperature application of austenitic chromium-nickel steels for energy production and process techniques. Material requirements are presented, and the behaviour, mechanical and physical properties of such steels are discussed. The manufacture of forgings is considered and test results presented. (Auth.)

Forgings made of austenitic chromium-nickel steels for the low temperature range

Energy Technology Data Exchange (ETDEWEB)

Gruendler, O.; Schwarz, W.; Koren, M. (Vereinigte Edelstahlwerke A.G. (VEW), Kapfenberg (Austria))

1981-09-01

The authors discuss the low temperature application of austenitic chromium-nickel steels for energy production and process techniques. Material requirements are presented, and the behaviour, mechanical and physical properties of such steels are discussed. The manufacture of forgings is considered and test results presented.

Fatigue and fracture behavior of low alloy ferritic forged steels

International Nuclear Information System (INIS)

Chaudhry, V.; Sharma, A.K.; Muktibodh, U.C.; Borwankar, Neeraj; Singh, D.K.; Srinivasan, K.N.; Kulkarni, R.G.

2016-01-01

Low alloy ferritic steels are widely used in nuclear industry for the construction of pressure vessels. Pressure vessel forged low alloy steels 20MnMoNi55 (modified) have been developed indigenously. Experiments have been carried out to study the Low Cycle Fatigue (LCF) and fracture behavior of these forged steels. Fully reversed strain controlled LCF testing at room temperature and at 350 °C has been carried out at a constant strain rate, and for different axial strain amplitude levels. LCF material behavior has been studied from cyclic stress-strain responses and the strain-life relationships. Fracture behavior of the steel has been studied based on tests carried out for crack growth rate and fracture toughness (J-R curve). Further, responses of fatigue crack growth rate tests have been compared with the rate evaluated from fatigue precracking carried out for fracture toughness (J-R) tests. Fractography of the samples have been carried out to reveal dominant damage mechanisms in crack propagation and fracture. The fatigue and fracture properties of indigenously developed low alloy steel 20MnMoNi55 (modified) steels are comparable with similar class of steels. (author)

Multi-objective optimization of swash plate forging process parameters for the die wear/service life improvement

Science.gov (United States)

Hu, X. F.; Wang, L. G.; Wu, H.; Liu, S. S.

2017-12-01

For the forging process of the swash plate, the author designed a kind of multi-index orthogonal experiment. Based on the Archard wear model, the influences of billet temperature, die temperature, forming speed, top die hardness and friction coefficient on forming load and die wear were numerically simulated by DEFORM software. Through the analysis of experimental results, the best forging process parameters were optimized and determined, which could effectively reduce the die wear and prolong the die service life. It is significant to increase the practical production of enterprise, especially to reduce the production cost and to promote enterprise profit.

Study on optimum length of raw material in stainless steel high-lock nuts forging

Science.gov (United States)

Cheng, Meiwen; Liu, Fenglei; Zhao, Qingyun; Wang, Lidong

2018-04-01

Taking 302 stainless steel (1Cr18Ni9) high-lock nuts for research objects, adjusting the length of raw material, then using DEFORM software to simulate the isothermal forging process of each station and conducting the corresponding field tests to study the effects of raw material size on the stainless steel high-lock nuts forming performance. The tests show that the samples of each raw material length is basically the same as the results of the DEFORM software. When the length of the raw material is 10mm, the appearance size of the parts can meet the design requirements.

Forging C-C Bonds Through Decarbonylation of Aryl Ketones.

Science.gov (United States)

Somerville, Rosie J; Martin, Ruben

2017-06-06

The ability of nickel to cleave strong σ-bonds is again in the spotlight after a recent report that demonstrates the feasibility of using nickel complexes to promote decarbonylation of diaryl ketones. This transformation involves the cleavage of two strong C-C(O) bonds and avoids the use of noble metals, hence reinforcing the potential of decarbonylation as a technique for forging C-C bonds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

DESY: Technology transfer on show

International Nuclear Information System (INIS)

Anon.

1991-01-01

As well as exploring the unknown, fundamental physics research, with its continual demands for special conditions and precision measurements, makes special demands on frontier technology. One of the most prolific areas of this technology transfer, superconductivity and cryogenics, was highlighted by a recent exhibition at DESY organized by the International Cryogenic Engineering Committee

DESY: Technology transfer on show

Energy Technology Data Exchange (ETDEWEB)

Anon.

1991-12-15

As well as exploring the unknown, fundamental physics research, with its continual demands for special conditions and precision measurements, makes special demands on frontier technology. One of the most prolific areas of this technology transfer, superconductivity and cryogenics, was highlighted by a recent exhibition at DESY organized by the International Cryogenic Engineering Committee.

2016 Geothermal Technologies Office Annual Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-03-01

This report highlights project successes and continued efforts in all of our program areas – EGS, Hydrothermal, Low-Temperature, and Systems Analysis – which are flanked by useful tools and resources and links to more information. Such highlights include FORGE and EGS successes, projects reducing geothermal costs and risks, and advancements in technology research and development.

The Influence of Temperature on the Frictional Behavior of Duplex-Coated Die Steel Rubbing Against Forging Brass

Science.gov (United States)

Ebrahimzadeh, I.; Ashrafizadeh, F.

2015-01-01

Improvement of die life under hot forging of brass alloys is considered vital from both economical and technical points of view. One of the best methods for improving die life is duplex coatings. In this research, the influence of temperature on the tribological behavior of duplex-coated die steel rubbing against forging brass was investigated. The wear tests were performed on a pin-on-disk machine from room temperature to 700 °C; the pins were made in H13 hot work tool steel treated by plasma nitriding and by PVD coatings of TiN-TiAlN-CrAlN. The disks were machined from a two-phase brass alloy too. The results revealed that the friction coefficient of this tribosystem went through a maximum at 550 °C and decreased largely at 700 °C. Furthermore, the formation of Cr2O3 caused the reduction of friction coefficient at 700 °C. PVD coatings proved their wear resistance up to 550 °C, well above the working temperature of the brass forging dies.

Microstructures and tensile properties of Mg–Gd–Y–Zr alloy during multidirectional forging at 773 K

International Nuclear Information System (INIS)

Tang, Liechong; Liu, Chuming; Chen, Zhiyong; Ji, Dawei; Xiao, Hongchao

2013-01-01

Highlights: • Rare earth (RE) containing Mg–Gd–Y–Zr alloy was successfully multidirectional forged for 8 passes without any cracks. • Initial coarse grains was refined due to a combination of discontinuous and continuous dynamic recrystallization. • The alloy MDFed after 6 passes exhibited an excellent balance of strength and ductility at room temperature. - Abstract: A homogenized Mg–10Gd–4.8Y–0.6Zr (wt.%) alloy was subjected to multidirectional forging (MDF) at 773 K. It was shown that the average grain size decreased with increasing cumulative strain till 6 passes. Uniform fine-grained structure with an average grain size of 9.3 μm was achieved after 6 passes, i.e., cumulative strain of 1.8. Results revealed that grain refinement was induced by a complicated combination of discontinuous dynamic recrystallization at low strain regions and continuous dynamic recrystallization or rotation recrystallization at medium-to-high strain regions. The alloy multi-directionally forged (MDFed) for 6 passes exhibited an excellent balance of strength and ductility at room temperature with ultimate tensile strength (UTS) of 336 MPa and elongation to fracture of 21.0%

Helium High Pressure Tanks at EADS Space Transportation New Technology with Thermoplastic Liner

National Research Council Canada - National Science Library

Benedic, Fabien; Leard, Jean-Philippe; Lefloch, Christian

2005-01-01

.... In order to achieve the new target prices, a new disruptive technology has been performing for several years in using a thermoplastic liner instead the usual expensive concept of metallic forged liner...

The modern CIO: forging a new role in the managed care era.

Science.gov (United States)

Griffin, J

1997-05-01

The advent of managed care has helped forge new roles for healthcare professionals. Competitive pressures, the profile of the member community, and provider network design drive healthcare delivery via the managed care model. Careful analysis and design of the managed care model charts the success or failure of the health care delivery system--usually an integrated delivery system (IDS). Therefore, those healthcare organizations that have chosen to get on the managed care bandwagon must re-invent themselves, both culturally and technologically. The chief information officer (CIO) leads this technological revolution. To work effectively, the technological infrastructure of the IDS must be closely in line with enterprise goals and objectives. In the managed care environment the old information system (IS) approach of supporting the operational needs of individual departments simply will not work. The CIO's new role will be to master the concept of managed care to ensure that enterprise-wide needs for operational, clinical, and financial information are met, and that IS and enterprise goals are aligned. CIOs who have an intuitive grasp of the managed care environment--although their numbers are growing as managed care mushrooms--make up a minority group. They are a special breed with clearly definable qualities such as business savvy and an affinity for big-picture thinking. To an IDS, a CIO with these qualities is a rare gem indeed. This article introduces Don Winschel, the associate administrator and CIO of Johnson City Medical Center (Johnson City, TN) as an example of one such modern CIO.

The Forging of a White Gay Aesthetic at the Saint, 1980–84

Directory of Open Access Journals (Sweden)

Tim Lawrence

2011-06-01

Full Text Available Based on original interviews with key protagonists and documentary research, the article examines the way in which the DJs who worked at the Saint forged a white gay aesthetic across the first half of the 1980s. A private party located in the East Village, New York, the Saint attracted a privileged white male crowd, and this group's position within the emerging culture of neoliberalism, along with the deepening impact of the AIDS epidemic, encouraged its spinners to sever their ties with sounds that were associated with blackness. However, if Saint DJs rejected a high proportion of records that were being released by New York's independents, and also snubbed Chicago house when it broke in 1985, their forging of an aesthetic that emphasised seamless transitions, often between records that contained similar sonic qualities, preempted the style of mixing that would be popularised in house music culture.

Quality surveillance for steel forgings of SA508 Gr.3 used on the main NI equipment of AP1000 nuclear island

International Nuclear Information System (INIS)

Liu Lizhao

2011-01-01

Being a type of steel with ideal weldability, outstanding ability of anti-neutron irradiation embitterment and good property of fracture toughness and impact toughness, the steel of ASME SA508-3 was used widely for the nuclear island equipment of PWR Nuclear Power Plant. For the 3rd generation nuclear power plant AP1000, all large forgings and some critical components of the SG, RV and PRZ adopt this steel. Through analysis on the critical technical points during manufacturing of the SA508-3 forgings, this article try to identify the key points should be paid attention during the quality surveillance for this type of forgings, and to put forward the supervision method and focus during quality surveillance activities. (author)

Characterization of a Viking Blade Fabricated by Traditional Forging Techniques

Science.gov (United States)

Vo, H.; Frazer, D.; Bailey, N.; Traylor, R.; Austin, J.; Pringle, J.; Bickel, J.; Connick, R.; Connick, W.; Hosemann, P.

2016-12-01

A team of students from the University of California, Berkeley, participated in a blade-smithing competition hosted by the Minerals, Metals, and Materials Society at the TMS 2015 144th annual meeting and exhibition. Motivated by ancient forging methods, the UC Berkeley team chose to fabricate our blade from historical smithing techniques utilizing naturally-occurring deposits of iron ore. This approach resulted in receiving the "Best Example of a Traditional Blade Process/Ore Smelting Technique" award for our blade named "Berkelium." First, iron-enriched sand was collected from local beaches. Magnetite (Fe3O4) was then extracted from the sand and smelted into individual high- and low-carbon steel ingots. Layers of high- and low-carbon steels were forge-welded together, predominantly by hand, to form a composite material. Optical microscopy, energy dispersive spectroscopy, and Vickers hardness mechanical testing were conducted at different stages throughout the blade-making process to evaluate the microstructure and hardness evolution during formation. It was found that the pre-heat-treated blade microstructure was composed of ferrite and pearlite, and contained many nonmetallic inclusions. A final heat treatment was performed, which caused the average hardness of the blade edge to increase by more than a factor of two, indicating a martensitic transformation.

Friction welding of a nickel free high nitrogen steel: influence of forge force on microstructure, mechanical properties and pitting corrosion resistance

Directory of Open Access Journals (Sweden)

Mrityunjoy Hazra

2014-01-01

Full Text Available In the present work, nickel free high nitrogen austenitic stainless steel specimens were joined by continuous drive friction welding process by varying the amount of forge (upsetting force and keeping other friction welding parameters such as friction force, burn-off, upset time and speed of rotation as constant at appropriate levels. The joint characterization studies include microstructural examination and evaluation of mechanical (micro-hardness, impact toughness and tensile and pitting corrosion behaviour. The integrity of the joint, as determined by the optical microscopy was very high and no crack and area of incomplete bonding were observed. Welds exhibited poor Charpy impact toughness than the parent material. Toughness for friction weld specimens decreased with increase in forge force. The tensile properties of all the welds were almost the same (irrespective of the value of the applied forge force and inferior to those of the parent material. The joints failed in the weld region for all the weld specimens. Weldments exhibited lower pitting corrosion resistance than the parent material and the corrosion resistance of the weld specimens was found to decrease with increase in forge force.

FLANDES, Flange Design for He Circuits by Taylor-Forge Method

International Nuclear Information System (INIS)

Pitchford, B.E.

1977-01-01

1 - Nature of the physical problem solved: Flange design for helium circuits. 2 - Method of solution: This is a flange design programme based on the Taylor forge method with an additional calculation of flange rotation and bolt load change during the application of internal pressure. The method relates only to the integral hub type of flange, with or without a secondary O-ring seal but will deal also with the flange and cover plate case

The Influence of Technological Conditions of the Process of Cogging in Flat Dies on the Quality of Two-Phase Titanium Alloys

Directory of Open Access Journals (Sweden)

Dyja Н.

2016-06-01

Full Text Available To create a rational technology of cogging process and to determinate the optimal values of the angles of tilt and single reduction the stress-strain state (SSS of the blank during cogging in the flat dies was analyzed. By using the finite element method and program MSC.SuperForge quantitative data are obtained and the basic patterns of distribution of SSS, the temperature during the simulation of tilting in flat dies with different angles of tilting and the amount of reduction were established. Sustainable experimental-industrial technology of forging of two-phase titanium alloys was developed and tested.

eFORGE : A Tool for Identifying Cell Type-Specific Signal in Epigenomic Data

NARCIS (Netherlands)

Breeze, Charles E.; Paul, Dirk S.; van Dongen, Jenny; Butcher, Lee M.; Ambrose, John C.; Barrett, James E.; Lowe, Robert; Rakyan, Vardhman K.; Iotchkova, Valentina; Frontini, Mattia; Downes, Kate; Ouwehand, Willem H.; Laperle, Jonathan; Jacques, Pierre-ETienne; Bourque, Guillaume; Bergmann, Anke K.; Siebert, Reiner; Vellenga, Edo; Saeed, Sadia; Matarese, Filomena; Martens, Joost H. A.; Stunnenberg, Hendrik G.; Teschendorff, Andrew E.; Herrero, Javier; Birney, Ewan; Dunham, Ian; Beck, Stephan

2016-01-01

Epigenome-wide association studies (EWAS) provide an alternative approach for studying human disease through consideration of non-genetic variants such as altered DNA methylation. To advance the complex interpretation of EWAS, we developed eFORGE (http://eforge.cs.ucl.ac.uk/), a new stand-alone and

Effect of forging on mechanical properties of rice husk ash-silicon carbide reinforced Al1100 hybrid composites

Science.gov (United States)

Ghanaraja, S.; Gireesha, B. L.; Ravikumar, K. S.; Likith, P.

2018-04-01

During the past few years, material design has changed prominence to pursue light weight, environment friendliness, low cost, quality, higher service temperature, higher elastic modulus, improved wear resistance and performance. Straight monolithic materials have limitations in achieving the above decisive factors. To overcome these limitations and to convince the ever increasing demand of modern day technology, Attention has been shifted towards Metal Matrix Composites (MMC). Stir casting route is most hopeful for synthesizing discontinuous reinforcement aluminium matrix composites because of its relative simplicity and easy adaptability with all shape casting process used in metal casting industry. Hybridization of metal matrix composites is the introduction of more than one type/kind, size and shape of reinforcement during processing of composites. It is carried out to obtain synergistic properties of different reinforcements and matrix used, which may not be rea1ised in monolithic alloy or in conventional monocomposites. The present study involves synthesis of hybrid composites by addition of the desired amount of Silicon Carbide (SiC) and Rice Husk Ash (RHA) particles in to the molten Al 1100-Mg alloy through stir casting technique fallowed by hot forging of the cast composites. The influence of increasing in the wt% (3, 6, 9, 12 and 15 wt%) of SiC particles addition (3 wt% Rice husk ash kept constant) on evolution of microstructure is studied through XRD and SEM and their impact on the mechanical properties like hardness and tensile strength of the resulting forged hybrid composites has been investigated.

Precipitation-hardening stainless steel bars, shapes, and forgings (ASME SA-564 with additional requirements)

International Nuclear Information System (INIS)

1975-05-01

A standard prescribing requirements for precipitation-hardening stainless steel bars, shapes, and forgings (ASME SA-564 with additional requirements) for nuclear and associated applications is presented. This standard supersedes RDT M 7-6T, dated January 1974. (U.S.)

Increasing of the lifetime of large forging dies by repairwelding

Science.gov (United States)

Duchek, M.; Koukolikova, M.; Kotous, J.; Majer, M.

2018-02-01

Repair welding is often used for rebuilding discarded or failed forging dies. It saves the cost of new tools. Increased useful life of repaired dies is another motivation for repair welding. This article focuses on the development of new filler materials for this purpose. The main goal was to prolong the life of tools of DIN 1.2714 material. Filler wires of two chemistries were made and several samples were experimentally welded. Metallographic and tribological analyses were carried out.

Use of Gleeble MAXStrain unit for study of damage development in hot forging

NARCIS (Netherlands)

Geijselaers, Hubertus J.M.; Wang, Chao; Miroux, A.; Recina, V.; van den Boogaard, Antonius H.; Saanouni, K.

2016-01-01

The standard Gleeble MAXStrain unit has been modified to allow axial elongation. Analyses indicate that in this way both positive and negative hydrostatic stresses can be achieved during forging simulations, depending on the amount of strain per hit. This opens the way to the study of the effect of

Stress corrosion of low alloy steel forgings

International Nuclear Information System (INIS)

Thornton, D.V.; Mould, P.B.; Patrick, E.C.

1976-01-01

The catastrophic failure of a steam turbine rotor disc at Hinkley Point 'A' Power station was shown to have been caused by the growth of a stress corrosion crack to critical dimensions. This failure has promoted great interest in the stress corrosion susceptibility of medium strength low alloy steel forgings in steam environments. Consequently, initiation and growth of stress corrosion cracks of typical disc steels have been investigated in steam and also in water at 95 0 C. Cracking has been shown to occur, predominantly in an intergranular manner, with growth rates of between 10 -9 and 10 -7 mm sec. -1 . It is observed that corrosion pitting and oxide penetration prior to the establishment of a stress corrosion crack in the plain samples. (author)

The evolution of microtexture and macrotexture during subtransus forging of Ti-10V-2Fe-3Al

International Nuclear Information System (INIS)

Raghunathan, S.L.; Dashwood, R.J.; Jackson, M.; Vogel, S.C.; Dye, D.

2008-01-01

The macrotextures and microtextures produced during α+β forging of Ti-10V-2Fe-3Al were characterised using neutron, in situ synchrotron X-ray and ex situ electron backscatter diffraction (EBSD). The EBSD analysis showed that the measured misorientation distributions at a strain of 0.8 and strain rates of 0.1 and 0.01s -1 were similar, with an average misorientation of 2.2 deg. During forging, the moderate cube macrotexture inherited from the parent material was converted into a moderate fibre texture, with the major change occurring between strains of 0.4 and 0.6. The synchrotron diffraction studies allowed the orientation evolution of individual grains to be characterised. At the highest strain rate of 0.1s -1 , this indicated a change in behaviour from dispersion of the crystal mosaic (peak angular spread) at low strains, to convergence of the crystal mosaic at larger strains. At lower strain rates, only convergence of the crystal mosaic was observed. It is suggested that these results indicate a change in mechanism between deformation-controlled behaviour during the early stages of deformation and a strain rate of 0.1s -1 and diffusional, recovery-controlled behaviour at lower strain rates and higher strains

Forging Alliances in Interdisciplinary Rehabilitation Research (FAIRR): A Logic Model.

Science.gov (United States)

Gill, Simone V; Khetani, Mary A; Yinusa-Nyahkoon, Leanne; McManus, Beth; Gardiner, Paula M; Tickle-Degnen, Linda

2017-07-01

In a patient-centered care era, rehabilitation can benefit from researcher-clinician collaboration to effectively and efficiently produce the interdisciplinary science that is needed to improve patient-centered outcomes. The authors propose the use of the Forging Alliances in Interdisciplinary Rehabilitation Research (FAIRR) logic model to provide guidance to rehabilitation scientists and clinicians who are committed to growing their involvement in interdisciplinary rehabilitation research. We describe the importance and key characteristics of the FAIRR model for conducting interdisciplinary rehabilitation research.

Ductile fracture evaluation of ductile cast iron and forged steel by nonlinear-fracture-mechanics. Pt. 1. Tensile test by large scaled test pieces with surface crack

International Nuclear Information System (INIS)

Kosaki, Akio; Ajima, Tatsuro; Inohara, Yasuto

1999-01-01

The ductile fracture tests of Ductile Cast Iron and Forged Steel under a tensile stress condition were conducted using large-scaled flat test specimens with a surface crack and were evaluated by the J-integral values, in order to propose an evaluation method of initiation of ductile fracture of a cask body with crack by nonlinear-fracture-mechanics. Following results were obtained. 1) 1 -strain relations of Ductile Cast Iron and Forged Steel under the tensile stress condition were obtained, which is necessary for the development of J-integral design curves for evaluating the initiation of ductile fracture of the cask body. 2) In case of Ductile Cast Iron, the experimental J-integral values obtained from strain-gauges showed a good agreement with the linear-elastic-theory by Raju and Newman at room temperature, in both elastic and plastic regions. But, at 70degC in plastic region, the experimental i-integral values showed middle values between those predicted by the linear-elastic-theory and by the non- linear-elastic- theory (based on the fully plastic solution by Yagawa et al.). 3) In case of Forged Steel at both -25degC and room temperature, the experimental i-integral values obtained from strain-gauges showed a good agreement with those predicted by the linear-elastic-theory by Raju and Newman, in the elastic region. In the plastic region, however, the experimental i-integral values fell apart from the curve predicted by the linear-elastic-theory by Raju and Newman, and also approached to those by the non-linear-elastic-theory with increasing strain.(author)

Manufacturing of ultra-large diameter 20 MnMoNi 5 5 steel forgings for reactor pressure vessels and their properties

International Nuclear Information System (INIS)

Onodera, S.; Kawaguchi, S.; Tsukada, H.; Moritani, H.; Suzuki, K.; Sato, I.

1983-01-01

A set of component material for PHWR RPV, including the largest forgings ever manufacture so far such as flanges (8,440 mm O.D.), shells and torus (7,960 mm O.D.) and dome (6,800 mm dia. in chord, 460 mm thick), was presented in the outline of manufacturing and properties. Even with increased dimensions and weight than the current largest forgings, the manufacture and the qualities achieved were satisfactory. These results encourage us in further developing PWRs and PHWRs with increased capacity. (orig.)

The Ties That Bind: How Social Capital Is Forged and Forfeited in Teacher Communities

Science.gov (United States)

Bridwell-Mitchell, E. N.; Cooc, North

2016-01-01

The effects of social capital on school improvement make it important to understand how teachers forge, maintain, or forfeit collegial relationships. Two common explanations focused on formal organizational features and individual characteristics do not address how social capital accrues from informal dynamics of teachers' interactions in…

Brittle Fracture Behaviors of Large Die Holders Used in Hot Die Forging

Directory of Open Access Journals (Sweden)

Weifang Zhang

2017-05-01

Full Text Available Brittle fracture of large forging equipment usually leads to catastrophic consequences. To avoid this kind of accident, the brittle fracture behaviors of a large die holder were studied by simulating the practical application. The die holder is used on the large die forging press, and it is made of 55NiCrMoV7 hot-work tool steel. Detailed investigations including mechanical properties analysis, metallographic observation, fractography, transmission electron microscope (TEM analysis and selected area electron diffraction (SAED were conducted. The results reveal that the material generated a large quantity of large size polyhedral M23C6 (M: Fe and Cr mainly and elongated M3C (M: Fe mainly carbides along the martensitic lath boundaries when the die holder was recurrently tempered and water-cooled at 250 °C during the service. The large size carbides lead to the material embrittlement and impact toughness degradation, and further resulted in the brittle fracture of the die holder. Therefore, the operation specification must be emphasized to avoid the die holder being cooled by using water, which is aimed at accelerating the cooling.

THE LEGAL PROTECTION FOR REAL LAND RIGHT HOLDER IN CASE OF FORGED RINCIK

Directory of Open Access Journals (Sweden)

Nirwana Nirwana

2017-12-01

Full Text Available The legal Protection For Real Land Right Holder in Case of Forged Rincik. The research aimed to investigate (1 the legal protection for the land owner whose possession was based on rincik evidence, and (2 the legal protection on the good-will buyer based on the forged rincik document used in the land sale transaction. This was the normative legal research, also called the library research or documentary study because the research was only conducted on the written regulations or other legal materials or secondary data consisting of the primary and secondary legal materials. The interview was performed to strengthen the theories and opinions in the research. The research also used the Secondary data. the data were analysed and presented using the qualitative descriptive method. The research result indicate that: (1 the real land owner with rincik possession issued after the year 1960 based on the decision of Indonesian Supreme Court No. 560K / PID / 2008 has not been fully protected due to the fact that the seller is funished for forging the rincik., returning the right to the land owner can not be carried out due to the decision of Indonesian Supreme Court Number. 482 / PK / Pdt / 2014 which make the buyer win, while the real land owner is the directed to sue the land seller to give the compensation: and (2 the legal protection on the good faith buyer based on forget rincik in the land sale transaction has been fully protected and has the ringt to possess the land based on the decision of Indonesian Supreme Court Number. 482/PK/Pdt/2014 because the buyer has bought the land in the presence of Temporary Land Title Registar.

Modeling Cavitation in ICE Pistons Made with Isothermal Forging

Directory of Open Access Journals (Sweden)

V.V. Astanin

2014-07-01

Full Text Available Possible causes for cavitations in parts made with an Al-Si eutectic alloy AK12D (AlSi12 were explored with mathematical and physical modeling with involved acoustic emission. Pores were formed from micro-cracks, which appear during the early stages of a deformation process, with the help of micro-stresses appearing at phase boundaries (Al/Si interface due to thermal expansion. At the design stage of isothermal forgings of such products it is recommended to provide a scheme of the deformed shape, which is under uniform compression, to compensate for the inter-phase stresses.

Automated ultrasonic shop inspection of reactor pressure vessel forgings

International Nuclear Information System (INIS)

Farley, J.M.; Dikstra, B.J.; Hanstock, D.J.; Pople, C.H.

1986-01-01

Automated ultrasonic shop inspection utilizing a computer-controlled system is being applied to each of the forgings for the reactor pressure vessel of the proposed Sizewell B PWR power station. Procedures which utilize a combination of high sensitivity shear wave pulse echo, 0 degrees and 70 degrees angled longitudinal waves, tandem and through-thickness arrays have been developed to provide comprehensive coverage and an overall reliability of inspection comparable to the best achieved in UKAEA defect detection trials and in PISC II. This paper describes the ultrasonic techniques, the automated system (its design, commissioning and testing), validation and the progress of the inspections

Discussion on Application of Space Materials and Technological Innovation in Dynamic Fashion Show

Science.gov (United States)

Huo, Meilin; Kim, Chul Soo; Zhao, Wenhan

2018-03-01

In modern dynamic fashion show, designers often use the latest ideas and technology, and spend their energy in stage effect and overall environment to make audience’s watching a fashion show like an audio-visual feast. With rapid development of China’s science and technology, it has become a design trend to strengthen the relationship between new ideas, new trends and technology in modern art. With emergence of new technology, new methods and new materials, designers for dynamic fashion show stage art can choose the materials with an increasingly large scope. Generation of new technology has also made designers constantly innovate the stage space design means, and made the stage space design innovated constantly on the original basis of experiences. The dynamic clothing display space is on design of clothing display space, layout, platform decoration style, platform models, performing colors, light arrangement, platform background, etc.

Influence of the hydrostatic stress component on critical surface expansion in forging compound products

DEFF Research Database (Denmark)

Vorm, T; Bay, Niels; Wanheim, Tarras

1974-01-01

of a superimposed hydrostatic pressure on the critical surface expansion during a forging process. The critical surface expansion appears to decrease with increasing hydrostatic pressure. This may be due to the fact that the close contact between the materials necessary to obtain bonding is created by a micro...

A Forging Hardness Dispersion Effect on the Energy Consumption of Machining

Directory of Open Access Journals (Sweden)

L. D. Mal'kova

2015-01-01

Full Text Available The aim of the work is to evaluate a hardness dispersion of forgings to be further machined, and analyse the impact of this dispersion on the resulting power consumption when cutting.The paper studies the hardness values of three kinds of parts for automotive manufacturing. Sample of each part was n = 100 pieces. Analysis of measurements showed that 46% - 93% of parts meet requirements for a range defined by the work-piece working drawing. It was found that hardness of one batch of forgings is under dispersion, which distribution is governed by the normal law.The work provides calculations for machining the external cylindrical surfaces of the considered parts. In the context of calculating are adopted parameters of the enterprise-processing rate. It is found that power consumption of machining because of the dispersion values of the work-piece hardness is a function of the random BH variable and it itself is a random variable. Two types of samples are considered, namely: the full sample and that of the values that meet requirements for hardness. The coefficient of variation for samples that meet the technical requirements for hardness is lower than for the full samples, so their average value is more reliable characteristic of a set. It was also found that to ensure a reliable prediction of power consumption in designing the manufacturing processes it is necessary to reduce a tolerance range of workpiece hardness to the limit.The work gives a comparative evaluation of electric power consumption per unit cylindrical surface of the parts under consideration. A relative change in the electric power consumed at the minimum and maximum levels of the hardness value was introduced as an evaluation criterion. It is found that with changing hardness of machined work-pieces within the tolerance, the change in power consumption in machining the unit surface reaches 16% while in the case its being out of the specified range it does 47%.

Cold forging stem of total hip prosthesis with hybrid mechanical properties

International Nuclear Information System (INIS)

Lopes, E.S.N.; Contieri, R.J.; Cardoso, F.F.; Cremasco, A.; Button, S.T.; Caram, R.

2010-01-01

Type β Ti alloy is one of the most versatile groups of materials with regard to mechanical properties. Aspects such as alloying elements selection, mechanical processing and heat treatment routes empower these materials in applications where hybrid mechanical behavior is necessary. The aim of this study is to produce stems of total hip prostheses with hybrid mechanical properties using Ti-Nb alloys. Ingots were produced by using arc melting. Following, samples were subjected to specific heat treatment aiming to make cold forging. Sample characterization includes X-ray diffraction, scanning electron microscopy, Vickers hardness tests and tensile test. The experiments performed allowed to examine the effects of heat treatment parameters on the microstructure and mechanical behavior. Finally, results obtained show that the application of specific heat treatments of quenching and aging makes feasible the manufacturing of orthopedic devices with hybrid mechanical properties with regions where high mechanical strength was prioritized, while in others, low elastic modulus was the main concern. (author)

The Use of 3D Scanning Methods to Evaluate the Hybrid Layer Used in Forging Tools in Order to Improve their Durability

Directory of Open Access Journals (Sweden)

Gronostajski Z.

2017-09-01

Full Text Available This study is focused on tools used in the industrial process of hot forging of a front wheel forging (gear wheel manufactured for the automotive industry. Five different variants were applied for the tools: 3 die inserts were coated with three different hybrid layers (PN + PVD type, i.e. AlCrTiN, AlCrTiSiN and CrN, one insert was only nitrided, and one was pad welded, to improve tool durability. The tool wear was analysed and represented by the material degradation on the working surface, based on the 3D scanning and the material growth of the periodically collected forgings. Additionally, the scanned tools were divided into two areas, in which it was found, based on the analysis, that various degradation mechanisms are predominant. Microstructural tests and hardness measurements of the analyzed tools were also performed. Based on the results, it was found that, in the central part of the die insert, thermo-mechanical fatigue, abrasive wear and plastic deformation occurred, while in the area of the bridge insert, only abrasive wear could be observed. For these areas, the loss of material was determined separately. It was established that the use of the GN+CrN and GN+AlCrTiN hybrid layers on forging tools improves their durability, while the best results in the central area were observed on the tool with the GN+CrN layer, which is the most resistant to thermo-mechanical fatigue. In the second analyzed area, good wear resistance occurred on GN+CrN, GN+AlCrTiN and pad welded inserts, for which, together with the increase of the forging number, a proportional, slight growth of the loss of material occurred.

Press forging of single crystal calcium fluoride

International Nuclear Information System (INIS)

Turk, R.R.

1975-01-01

Single crystals of high-purity calcium fluoride have been deformed uniaxially in an attempt to improve strength and resistance to cleavage, without impairing infrared transmission. Order of magnitude increases in strength, such as those found in forged KCl, have not been attained, but fine-grained polycrystalling material has been produced which is resistant to crystalline cleavage. Deformation rates of 10 -2 min -1 , reductions of 10 to 73 percent in height, and deformation temperatures of 550 to 1000 0 C have been used. Flexural strengths over 13,000 psi and grain sizes down to 5 μm have been obtained. Reduction of residual stress through heat treatment has been studied, and resultant techniques applied before, during, and after deformation. No increase in infrared absorption has been noted at the CO laser wavelength of 5.3 μm

Analytical and experimental evaluation of a proposed self-forging fragment munition

International Nuclear Information System (INIS)

Tuft, D.B.; Folsom, E.N.

1982-01-01

Analytical and experimental tools have been used to study the formation of a proposed self-forging fragment projectile. The primary objective of this study is the determination of the interior and exterior shape of the fully formed fragment, and to determine if the fragment tumbles in flight. In addition, it is of interest to compare computer predictions to experimental results. An experiment was performed using high speed photography and high-energy flash x-ray radiography to study liner and case motion and projectile formation. Fabrication and assembly tolerances were closely controlled in an effort to eliminate tolerances as a possible source of fragment instability. X-ray film-density contours were analyzed to determine the fully formed fragment interior and exterior shape. Down-range yaw screens showed fragment tumbling in flight. The computed fragment shape was compared to experimental results and it was found that a retaining ring in the computational model near the liner periphery had a significant effect on the final computed fragment shape. With the retaining ring in the computational model and full two-way sliding between all material interfaces, the final computed fragment showed very good agreement with the experiment on both exterior and interior shapes

Fostering Technology-Rich Service-Learning Experiences between School Librarians and Teacher Education Programs

Science.gov (United States)

Shepherd, Craig E.; Dousay, Tonia; Kvenild, Cassandra; Meredith, Tamara

2015-01-01

School libraries are untapped resources for fieldwork by preservice teachers. Many school librarians have expertise in pedagogy and standards-based curriculum development, both for information literacy and for technology integration. By forging partnerships with teacher-preparation programs, school librarians can provide fieldwork sites rich in…

Self-adaptive multimethod optimization applied to a tailored heating forging process

Science.gov (United States)

Baldan, M.; Steinberg, T.; Baake, E.

2018-05-01

The presented paper describes an innovative self-adaptive multi-objective optimization code. Investigation goals concern proving the superiority of this code compared to NGSA-II and applying it to an inductor’s design case study addressed to a “tailored” heating forging application. The choice of the frequency and the heating time are followed by the determination of the turns number and their positions. Finally, a straightforward optimization is performed in order to minimize energy consumption using “optimal control”.

Room and high temperature deformation behaviour of a forged Fe–15Al–5Nb alloy with a reinforcing dispersion of equiaxed Laves phase particles

International Nuclear Information System (INIS)

Morris, D.G.; Muñoz-Morris, M.A.

2012-01-01

Highlights: ► Forged Fe–15%Al–5%Nb has a composite structure of soft matrix with equiaxed Laves phase particles. ► The material shows good strength with excellent ductility at room temperature. ► Good creep strength is maintained to 700 °C. ► The coarse composite microstructure ensures good long term stability at high temperatures. ► High temperature strength depends on load sharing between phases and microstructural refinement. - Abstract: The cast-in network of continuous Laves phase in a Fe–15%Al–5%Nb alloy has been converted to a dispersion of coarse Laves phase particles by high temperature forging, and the room temperature and high temperature deformation behaviour examined. The material shows good room temperature tensile ductility and good creep strength at temperatures up to 700 °C. The good high temperature strength is explained by the refinement of substructure by the dispersion of Laves phase particles and load and strain partitioning between the stiff and hard phase and the softer matrix. The relatively coarse microstructure is expected to be highly stable against coarsening at high temperatures, which should allow retention of creep properties even for long exposure times.

Assessment of residual stress of 7050-T7452 aluminum alloy forging using the contour method

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zheng [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Yang, Yinfei, E-mail: yyfgoat@nuaa.edu.cn [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Li, Liang [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Chen, Bo; Tian, Hui [Xi’an Aircraft Industrial (Group) Co. Ltd., Xi’an 710000 (China)

2015-09-17

The cold-compression stress relief process has been used to reduce the quench-induced stresses in high-strength aerospace aluminum alloy forgings. However, this method does not completely relieve the stress. Longitudinal residual stresses in 7050-T7452 aluminum alloy forging were measured with contour method. The measuring procedure of the contour method including specimen cutting under clamps with a wire electrical discharge machine, contour measurement of the cut surface with a laser scanner, careful data processing and elastic finite element analysis was introduced in detail. In addition, multiple cuts were used to map cross sectional stress at different cut surfaces. Finally, the longitudinal residual stress throughout the cut plane was mapped, and through thickness longitudinal stress profiles were also analyzed. Investigated results suggest that spatial variation of stress distribution can be attributed to the non-uniform plastic deformation of the cold-compression stress relief process. The overall reduction of peak stress magnitudes is approximately 43–79%.

Assessment of residual stress of 7050-T7452 aluminum alloy forging using the contour method

International Nuclear Information System (INIS)

Zhang, Zheng; Yang, Yinfei; Li, Liang; Chen, Bo; Tian, Hui

2015-01-01

The cold-compression stress relief process has been used to reduce the quench-induced stresses in high-strength aerospace aluminum alloy forgings. However, this method does not completely relieve the stress. Longitudinal residual stresses in 7050-T7452 aluminum alloy forging were measured with contour method. The measuring procedure of the contour method including specimen cutting under clamps with a wire electrical discharge machine, contour measurement of the cut surface with a laser scanner, careful data processing and elastic finite element analysis was introduced in detail. In addition, multiple cuts were used to map cross sectional stress at different cut surfaces. Finally, the longitudinal residual stress throughout the cut plane was mapped, and through thickness longitudinal stress profiles were also analyzed. Investigated results suggest that spatial variation of stress distribution can be attributed to the non-uniform plastic deformation of the cold-compression stress relief process. The overall reduction of peak stress magnitudes is approximately 43–79%

Forging And Milling Contribution On Residual Stresses For A Textured Biphasic Titanium Alloy

International Nuclear Information System (INIS)

Deleuze, C.; Fabre, A.; Barrallier, L.; Molinas, O.

2011-01-01

Ti-10V-2Fe-3Al is a biphasic titanium alloy (α+β) used in aeronautical applications for its mechanical properties, such as its yield strength of 1200 MPa and it weighs 40% less than steel. This alloy is particularly useful for vital parts with complex geometry, because of its high forging capability. In order to predict the capability for fatigue lifetime, the designers need to know the residual stresses. X-Ray diffraction is the main experimental technique used to determine residual stresses on the surface. In this case, stress levels are primarily influenced by the complex forging and milling process. On this alloy in particular, it may be difficult to characterize stress due to modification of the microstructure close to the surface. Results obtained by x-ray analysis depend on the correct definition of the shape of the diffraction peaks. The more precisely defined the position of the peak, the more accurately the stresses are evaluated. This paper presents a method to detect if residual stresses can be characterized by x-ray diffraction. The characterization of hardness seems to be a relevant technique to quickly analyze the capability of x-ray diffraction to determine residual stresses.

Study of the structural and mechanical properties of the alloy U-0.2V (weight percent) forged in the α phase

International Nuclear Information System (INIS)

Couterne, A.; Guillaume, C.

1980-01-01

The effects of forging carried out in the 2 phase on the structural properties of the alloy U-0.2V (evtl.%) carburized or not have been studied. A carbon content of the order of 300 x 10 6 , contrary to the one used for the cast alloy, is neither detrimental to the micrographic structure nor to the mechanical properties of the alloy. The forged plates have a semicrystalline structure with alternative, formed bands, on the one hand by small recrystallization grains, on the other by quite deformed coarse grains. The preferential orientations developed resume to a fibrous structure. The fiber axis, practically the [002] axis, is parallell to the normal to the surface of the forged disc. This result implies a good isotropy of the dilatometric and mechanical properities in the whole plane parallel to the disc faces. A correlation has been made between the found structure and the thermal expansion of the material. Furthermore, the mechanical characteristics reach an excellent level (Rsup(M) approx. 900 MPa, A approx. 38%). (orig.)

Forging School-Scientist Partnerships: A Case of Easier Said than Done?

Science.gov (United States)

Falloon, Garry

2013-12-01

Since the early 1980s, a number of initiatives have been undertaken worldwide which have involved scientists and teachers working together in projects designed to support the science learning of students. Many of these have attempted to establish school-scientist partnerships. In these, scientists, teachers, and students formed teams engaged in mutually beneficial science-based activities founded on principles such as equal recognition and input, and shared vision, responsibility and risk. This article uses two partnership programmes run by a New Zealand Science Research Institute, to illustrate the challenges faced by scientists and teachers as they attempted to forge meaningful and effective partnerships. It argues that achieving the theorised position of a shared partnership space at the intersection of the worlds of scientists and teachers is problematic, and that scientists must instead be prepared to penetrate deeply into the world of the classroom when undertaking any such interactions. Findings indicate epistemological differences, curriculum and school systems and issues, and teacher efficacy and science knowledge significantly affect the process of partnership formation. Furthermore, it is argued that a re-thinking of partnerships is needed to reflect present economic and education environments, which are very different to those in which they were originally conceived nearly 30 years ago. It suggests that technology has an important role to play in future partnership interactions.

Research on Oxidation Wear Behavior of a New Hot Forging Die Steel

Science.gov (United States)

Shi, Yuanji; Wu, Xiaochun

2018-01-01

Dry sliding tests for the hot forging die steel DM were performed in air under the test temperature at 400-700 °C and the time of 0.5-4 h by a UMT-3 high-temperature wear tester. The wear behavior and characteristics were studied systematically to explore the general characters in severe oxidation conditions. The results showed that a mild-to-severe oxidation wear transition occurred with an increase in the test temperature and duration. The reason was clarified as the unstable M6C carbides coarsening should be responsible for the severe delamination of tribo-oxide layer. More importantly, an intense oxidation wear with lower wear rates was found when the experimental temperature reaches 700 °C or after 4 h of test time at 600 °C, which was closely related to the degradation behavior during wear test. Furthermore, a new schematic diagram of oxidation wear of DM steel was proposed.

Process parameter influence on Electro-sinter-forging (ESF) of titanium discs

DEFF Research Database (Denmark)

Cannella, Emanuele; Nielsen, Chris Valentin; Bay, Niels

Electro-sinter-forging (ESF) is a sintering process based on the resistance heating principle, which makes it faster than conventional sintering. The process is investigated as a function of the main process parameters, namely compacting pressure, electrical current density and sintering time....... The present work is focused on analysing the influence of these process parameters on the final density of a disc sample made from commercially pure titanium powder. Applying the design of experiments (DoE) approach, the electrical current was seen to be of largest influence. The maximum obtained density...

Slip-line field analysis of metal flow during two dimensional forging

International Nuclear Information System (INIS)

Fenton, R.G.; Khataan, H.A.

1981-01-01

A method of computation and a computer software package were developed for solving problems of two dimensional plastic flow between symmetrical dies of any specified shape. The load required to initiate plastic flow, the stress and velocity distributions in the plastic region of the metal, and the pressure distribution acting on the die are determined. The method can be used to solve any symmetrical plane strain flow problem regardless of the complexity of the die. The accurate solution obtained by this efficient method can provide valuable help to forging die designers. (Author) [pt

The FORGE AHEAD clinical readiness consultation tool: a validated tool to assess clinical readiness for chronic disease care mobilization in Canada's First Nations.

Science.gov (United States)

Hayward, Mariam Naqshbandi; Mequanint, Selam; Paquette-Warren, Jann; Bailie, Ross; Chirila, Alexandra; Dyck, Roland; Green, Michael; Hanley, Anthony; Tompkins, Jordan; Harris, Stewart

2017-03-23

Given the astounding rates of diabetes and related complications, and the barriers to providing care present in Indigenous communities in Canada, intervention strategies that take into account contextual factors such as readiness to mobilize are needed to maximize improvements and increase the likelihood of success and sustainment. As part of the national FORGE AHEAD Program, we sought to develop, test and validate a clinical readiness consultation tool aimed at assessing the readiness of clinical teams working on-reserve in First Nations communities to participate in quality improvement (QI) to enhance diabetes care in Canada. A literature review was conducted to identify existing readiness tools. The ABCD - SAT was adapted using a consensus approach that emphasized a community-based participatory approach and prioritized the knowledge and wisdom held by community members. The tool was piloted with a group of 16 people from 7 provinces and 11 partnering communities to assess language use, clarity, relevance, format, and ease of completion using examples. Internal reliability analysis and convergence validity were conducted with data from 53 clinical team members from 11 First Nations communities (3-5 per community) who have participated in the FORGE AHEAD program. The 27-page Clinical Readiness Consultation Tool (CRCT) consists of five main components, 21 sub-components, and 74 items that are aligned with the Expanded Chronic Care Model. Five-point Likert scale feedback from the pilot ranged from 3.25 to 4.5. Length of the tool was reported as a drawback but respondents noted that all the items were needed to provide a comprehensive picture of the healthcare system. Results for internal consistency showed that all sub-components except for two were within acceptable ranges (0.77-0.93). The Team Structure and Function sub-component scale had a moderately significant positive correlation with the validated Team Climate Inventory, r = 0.45, p < 0.05. The

Taking the Lead in Science Education: Forging Next-Generation Science Standards. International Science Benchmarking Report. Appendix

Science.gov (United States)

Achieve, Inc., 2010

2010-01-01

This appendix accompanies the report "Taking the Lead in Science Education: Forging Next-Generation Science Standards. International Science Benchmarking Report," a study conducted by Achieve to compare the science standards of 10 countries. This appendix includes the following: (1) PISA and TIMSS Assessment Rankings; (2) Courses and…

Forging the frontiers: Travellers and documents on the South Africa-Mozambique border, 1890s-1940s

Directory of Open Access Journals (Sweden)

Andrew MacDonald

Full Text Available It is well known that the Union of South Africa started to build an onerous border regime at the turn of the twentieth century in order to secure a White Man's Country in southern Africa. Newly formed, ambitious Immigration Departments consequently targeted 'Asiatics', poor whites and finally 'surplus' Africans from the 1920s onwards. An infrastructure of exclusion (detention and deportation compounds, police patrols, fingerprint offices and so on soon emerged at the region's maritime gateways as the colonial states sought to undermine decentralised indigenous societies characterised by long-term mobility. This article shows that the Union remained vulnerable on its eastern frontier with Mozambique and Swaziland, where 'undesirables' continued to arrive in numbers. Long-distance movement had a long precedent in these borderlands, and it proved difficult for colonial states to forge effective border controls until deep into the twentieth century. Based on extensive and critical engagement with multiple border control archives, the article traces the gradual 'paperisation of the border, and follows a thriving market in identity permits in southern Mozambique and Swaziland, which became important backdoor entry points to the Union. The main people to exploit corrupt local officials and entrepreneurial headmen on either side of the border were those associated with the merchant houses of coastal west India, syndicates from the Portuguese Atlantic island of Madeira, and long-distance, so-called 'tropical', African migrants. Together they forged sophisticated networks that moved permits, people and money across the region and gave south-east Africa's border builders hard and often thankless paperwork.

A Comparative Study on Wear Properties of As Cast, Cast Aged and Forge Aged A356 Alloy with Addition of Grain Refiner and/or Modifier

Directory of Open Access Journals (Sweden)

D.G. Mallapur

2015-03-01

Full Text Available In the present work, a comparative wear behavior study of three categories of materials viz, as cast, cast aged (casting followed by T6 and forge aged (forging followed by T6 has been investigated. Neither melt treatment nor solid state processing (like aging and forging seems to be altering the wear behavior of the materials drastically. Cast aged A356 materials exhibit higher wear resistance compared to as cast and forge aged A356 materials. Further, it was observed that cast aged samples register lower coefficient of friction compared to other samples. It is also noted that the difference in wear behavior is revealed only at conditions of higher load, higher speed and longer sliding distance of testing. At lower regimes the difference is marginal. Among cast aged samples, ones treated with combined addition exhibit better wear resistance compared to other materials. Samples treated with combined addition register lowest coefficient of friction followed by samples treated with Sr, those with B, those with Ti and untreated ones. Abrasive wear mechanism is found to be operative in the regime of higher loading and higher velocity of sliding. Adhesive wear mechanism seems to be dominating the wear process at the lower regime of load and velocity of sliding.

Analysis and outlook of applications of blockchain technology to equity crowdfunding in China

OpenAIRE

Zhu, Huasheng; Zhou, Zach Zhizhong

2016-01-01

Equity crowdfunding via the Internet is a new channel of raising money for startups. It features low barriers to entry, low cost, and high speed, and thus encourages innovation. In recent years, equity crowdfunding in China has experienced some developments. However, some problems remain unsolved in practice. Blockchain is a decentralized and distributed ledger technology to ensure data security, transparency, and integrity. Because it cannot be tampered with or forged, the technology is deem...

76 FR 24856 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

Science.gov (United States)

2011-05-03

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-803] Heavy Forged Hand Tools (i.e... Administration, International Trade Administration, Department of Commerce. SUMMARY: On January 3, 2011, the Department of Commerce (``Department'') initiated a sunset review of the antidumping duty orders on heavy...

Effect of the As-Forged and Heat-Treated Microstructure on the Room Temperature Anisotropic Ductile Fracture of Inconel 718

Science.gov (United States)

Teimouri, Javad; Hosseini, Seyed Rahman; Farmanesh, Khosro

2018-05-01

The purpose of the present work was to investigate the effect of primary carbides and the δ-phase on the anisotropic ductile fracture of Inconel 718 in the forging process. Inconel 718 alloys were prepared by VIM + VAR processes with various carbon contents (0.009 and 0.027 wt.%). Then, the alloys were forged and annealed at temperatures of 980 and 1030 °C. The room temperature mechanical anisotropy of the alloys was evaluated at the longitudinal direction (LD) and transverse direction (TD). Tensile and impact tests were used to characterize the mechanical properties of the specimens. The microstructural characterization and the fractography of the alloys were carried out by FE-SEM. The obtained results showed that the fracture strain and the impact energy in the TD were 30-50% lower than the LD. The fracture was accelerated by the δ-phase, leading to the reduction of impact energy in the longitudinal and the lateral directions up to 50%. The low-carbon alloy indicated similar characteristics in both the LD and the TD. Aligned carbides changed the fracture path from a zigzag path in the LD to a fibrous path in the TD, while the δ-phase created a flat fracture path. The shear lip area ratio in the tensile fracture cross section was decreased by reducing ductility.

Generation and development of damage in double forged tungsten in different combined regimes of irradiation with extreme heat loads

Science.gov (United States)

Paju, Jana; Väli, Berit; Laas, Tõnu; Shirokova, Veroonika; Laas, Katrin; Paduch, Marian; Gribkov, Vladimir A.; Demina, Elena V.; Prusakova, Marina D.; Pimenov, Valeri N.; Makhlaj, Vadym A.; Antonov, Maksim

2017-11-01

Armour materials in fusion devices, especially in the region of divertor, are exposed to a continuous heat and particle load. In addition, several off-normal events can reach the material during a work session. Calculations show that the effects of plasma and heat during such events can lead to cracking, erosion and detachment of the armour material. On the other hand, mutual and combined influences of different kinds of heat and particle loads can lead to the amplification of defects or vice versa, to the mitigation of damages. Therefore, the purpose of the study is to investigate the plasma induced damages on samples of double forged tungsten, which is considered a potential candidate for armour material of future tokamak's divertor. The combined effect of different kinds of plasma induced damages was investigated and analysed in this research. The study was conducted by irradiating the samples in various irradiation regimes twice, to observe the accumulation of the damages. Afterwards the analysis of micro-topography, scanning electron microscopy images and electrical conductivity measurements was used. Results indicate that double-forging improved the tungsten's durability to irradiation. Nevertheless, powerful pulses lead to significant damage of the sample, which will lead to further deterioration in the bulk. Although the average micro-roughness on the sample's surface does not change, the overall height/depth ratios can change.

New lubricant systems for cold and warm forging – advantages and limitations

DEFF Research Database (Denmark)

Bay, Niels

2011-01-01

. The present paper gives an overview of these efforts substituting environmentally hazardous lubricants in cold, warm and hot forging by new, more harmless lubricants. Introduction of these new lubricants, however, has some drawbacks due to lower limits of lubrication leading to risk of pick-up, poor product......The increasing focus on environmental issues and the requirements to establish solutions diminishing the impact on working environment as well as external environment has strongly motivated the efforts to develop new, environmentally friendly tribological systems for metal forming production...

Movement Synchrony Forges Social Bonds Across Group Divides

Directory of Open Access Journals (Sweden)

Bahar eTuncgenc

2016-05-01

Full Text Available Group dynamics play an important role in the social interactions of both children and adults. A large amount of research has shown that merely being allocated to arbitrarily defined groups can evoke disproportionately positive attitudes toward one’s in-group and negative attitudes toward out-groups, and that these biases emerge in early childhood. This prompts important empirical questions with far-reaching theoretical and applied significance. How robust are these inter-group biases? Can biases be mitigated by behaviors known to bond individuals and groups together? How can bonds be forged across existing group divides? To explore these questions, we examined the bonding effects of interpersonal synchrony on minimally constructed groups in a controlled experiment. In-group and out-group bonding were assessed using questionnaires administered before and after a task in which groups performed movements either synchronously or non-synchronously in a between-participants design. We also developed an implicit behavioral measure, the Island Game, in which physical proximity was used as an indirect measure of interpersonal closeness. Self-report and behavioral measures showed increased bonding between groups after synchronous movement. Bonding with the out-group was significantly higher in the condition in which movements were performed synchronously than when movements were performed non-synchronously between groups. The findings are discussed in terms of their importance for the developmental social psychology of group dynamics as well as their implications for applied intervention programs.

The production of grain oriented lanthanum titanate (La2Ti2O7) ceramics by uniaxial hot-forging process for improved fracture toughness

International Nuclear Information System (INIS)

Ceylan, Ali

2008-01-01

The layered-structural ceramics, such as lanthanum titanate (La 2 Ti 2 O 7 ), have been known for their good electrical and optical properties at high frequencies and temperatures. However, few studies have been conducted on the mechanical properties of these ceramics. The interest in ceramic hot-forging (HF) has been greatly increased recently due to the enhancement in fracture toughness via bridging effect of oriented grains. In this study, grain oriented lanthanum titanate was produced by the hot-forging process. The characterizations of the samples were achieved by density measurement, scanning electron microscopy (SEM), optical microscopy, X-ray diffraction (XRD), Vickers indentation and three-point bending test. According to X-ray diffraction patterns, the orientation factor (f) was found to be 0.73 for certain hot-forging conditions resulting an improved fracture toughness. The improved fracture toughness of La 2 Ti 2 O 7 (3.2 MPa m 1/2 ) reached to the value of monolithic alumina (Al 2 O 3 ) between 3 and 4 MPa m 1/2

Texture evolution in upset-forged P/M and wrought tantalum: Experimentation and modeling

International Nuclear Information System (INIS)

Bingert, J.F.; Desch, P.B.; Bingert, S.R.; Maudlin, P.J.; Tome, C.N.

1997-11-01

Preferred orientations in polycrystalline materials can significantly affect their physical and mechanical response through the retention of anisotropic properties inherent to the single crystal. In this study the texture evolution in upset-forged PIM and wrought tantalum was measured as a function of initial texture, compressive strain, and relative position in the pressing. A / duplex fiber texture parallel to the compression axis was generally observed, with varying degrees of a radial component evident in the wrought material. The development of deformation textures derives from restricted crystallographic slip conditions that generate lattice rotations, and these grain reorientations can be modeled as a function of the prescribed deformation gradient. Texture development was simulated for equivalent deformations using both a modified Taylor approach and a viscoplastic self-consistent (VPSC) model. A comparison between the predicted evolution and experimental results shows a good correlation with the texture components, but an overly sharp prediction at large strains from both the Taylor and VPSC models

Effect of Minor Titanium Addition on Copper/Diamond Composites Prepared by Hot Forging

Science.gov (United States)

Yang, Fei; Sun, Wei; Singh, Ajit; Bolzoni, Leandro

2018-03-01

Copper/diamond composites have great potential to lead the next generation of advanced heat sink materials for use in high-power electronic devices and high-density integrated circuits because of their potential excellent properties of high thermal conductivity and close thermal expansion to the chip materials (e.g., Si, InP, GaAs). However, the poor wettability between copper and diamond presents a challenge for synthesizing copper/diamond composites with effective metallurgical bonding and satisfied thermal performance. In this article, copper/diamond composites were successfully prepared by hot forging of elemental copper and artificial diamond powders with small amounts (0 vol.%, 3 vol.% and 5 vol.%) of titanium additives. Microstructure observation and mechanical tests showed that adding minor titanium additions in the copper/diamond composite resulted in fewer cracks in the composites' microstructure and significantly improved the bonding between the copper and diamond. The strongest bonding strength was achieved for the copper/diamond composite with 3 vol.% titanium addition, and the possible reasons were discussed.

Development of a 3D Finite Element code for Forging - An overview of the Brite/Euram project EFFORTS

DEFF Research Database (Denmark)

Bay, Niels; Andreasen, Jan Lasson; Olsson, David Dam

2001-01-01

The present paper presents an overview of the Brite/EuRam project EFFORTS (Enhanced Framework for FOrging design using Reliable Three-dimensional Simulation). A short description is given of methodologies developed including improvements of the numerical analysis, establishment of new constitutive...

Examining the patterns of innovation in low carbon energy science and technology: Publications and patents of Asian emerging economies

International Nuclear Information System (INIS)

Wong, Chan-Yuan; Fatimah Mohamad, Zeeda; Keng, Zi-Xiang; Ariff Azizan, Suzana

2014-01-01

This paper focuses on selected Asian emerging economies. The study employs publications and patents as proxies for science and technology, and its analysis is divided into three main parts: production trends, catching-up trends and patterns of convergence. The findings resulted in four salient points to be considered by policy makers: (1) ASEAN-4 lagged significantly behind the more advanced economies (Korea, Taiwan and China) even though their performance was identical in the early 1990s. China has forged ahead in terms of scientific publications and patents production, but lags behind in patents quality; (2) compared to the world average, the region as a whole has high potential to forge ahead in low carbon energy scientific production. (3) Advanced economies in Asia kicked off their low carbon energy science and technology development more from technological rather than scientific production, with no straightforward co-evolution between the two competencies. This demonstrates the need for a strong science-based technological foundation and a high level of dynamism for low carbon energy technology development; and (4) the economies demonstrated contrasting development trends in their focus between the supply and demand sides of energy technology development. The performance of the advanced economies is higher in ‘demand-side’ low carbon energy innovations

Optimizing noise control strategy in a forging workshop.

Science.gov (United States)

Razavi, Hamideh; Ramazanifar, Ehsan; Bagherzadeh, Jalal

2014-01-01

In this paper, a computer program based on a genetic algorithm is developed to find an economic solution for noise control in a forging workshop. Initially, input data, including characteristics of sound sources, human exposure, abatement techniques, and production plans are inserted into the model. Using sound pressure levels at working locations, the operators who are at higher risk are identified and picked out for the next step. The program is devised in MATLAB such that the parameters can be easily defined and changed for comparison. The final results are structured into 4 sections that specify an appropriate abatement method for each operator and machine, minimum allowance time for high-risk operators, required damping material for enclosures, and minimum total cost of these treatments. The validity of input data in addition to proper settings in the optimization model ensures the final solution is practical and economically reasonable.

2017 Status report-Tritium aging studies on stainless steel: Effect of hydrogen, tritium and decay helium on the fracture-toughness properties of stem, cup and block forgings

Energy Technology Data Exchange (ETDEWEB)

Morgan, Michael J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-06-28

The materials of construction of tritium reservoirs are forged stainless steels. During service, the structural properties of the stainless steel change over time because of the diffusion of tritium into the reservoir wall and its radioactive decay to helium-3. This aging effect can cause cracks to initiate and grow which could result in a tritium leak or delayed failure of a tritium reservoir. Numerous factors affect the tendency for crack formation and propagation and are being investigated in this program. The goal of the research is to provide relevant fracture mechanics data that can be used by the design agencies in their assessments of tritium reservoir structural integrity. In this status report, new experimental results are presented on the effects of tritium and decay helium on the cracking properties of specimens taken from actual tritium reservoir forgings instead of the experimental forgings of past programs. The properties measured are more representative of actual reservoir properties because the microstructure of the specimens tested are more like that of the actual tritium reservoirs. The program was designed to measure the effects of material variables on tritium compatibility and includes two stainless steels (Type 304L and 316L stainless steel), multiple yield strengths (360-500 MPa), and multiple forging shapes (Stem, Cup, and Block).

Microstructure evolution of superalloy for large exhaust valve during hot forging

International Nuclear Information System (INIS)

Jeong, H.S.; Cho, J.R.; Park, H.C.

2004-01-01

The nickel-based alloy Nimonic 80A possesses strength, and corrosion, creep and oxidation resistance at high temperature. These products are used for aerospace, marine engineering and power generation, etc. The control of forging parameters such as strain, strain rate, temperature and holding time is important because the microstructure change in hot working affects the mechanical properties. It is necessary to understand the microstructure variation evolution. The microstructure change evolution occurs by recovery, recrystallization and grain growth phenomena. The dynamic recrystallization evolution has been studied in the temperature range 950-1250 deg. C and strain rate range 0.05-5s-1 using hot compression tests. The metadynamic recrystallization and grain growth evolution has been studied in the temperature range 950-1250 deg. C and strain rate range 0.05, 5s-1, holding time range 5, 10, 100, 600 sec using hot compression tests. Modeling equations are developed to represent the flow curve, recrystallized grain size, recrystallized fraction and grain growth phenomena by various tests. Parameters of modeling equation are expressed as a function of the Zener-Hollomon parameter. The modeling equation for grain growth is expressed as a function of initial grain size and holding time. The developed modeling equation was combined with thermo-viscoplastic finite element modeling to predict various microstructure change evolution during thermo mechanical processing. The predicted grain size in developed FE simulation results is compared with results obtained in various tests. In order to obtain a final microstructure and good mechanical properties in forging, the FEM would become a useful tool in the simulation of the microstructure development

Forging Alliances with Protection and Advocacy Systems: A Training Manual for Parents of Children with Emotional Disorders.

Science.gov (United States)

Petr, Christopher G.

This manual is intended to be used in conjunction with a 1-day training workshop to help parents of children with emotional disorders establish working alliances with protection and advocacy agencies for people with mental illness (PAMIs). The workshop prepares parents for developing specific plans for forging alliances with the state PAMI. The…

Progressive forging. Alternate process to little capacities presses; Forjamento progressivo. Processo alternativo para prensas de pequena capacidade

Energy Technology Data Exchange (ETDEWEB)

Schaeffer, Lirio; Brito, Alberto M.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Metalurgia

1986-12-31

This work presents several alternatives and possibilities to incremental forging. Some experimental results are presented.Lead was used to simulate the material flow. The influence of the sample geometry and the best way to perform further experiences with titanium alloy Ti A16 V4 were analyzed. 11 figs., 2 tabs., 9 refs.

Forging Fluorine‐Containing Quaternary Stereocenters by a Light‐Driven Organocatalytic Aldol Desymmetrization Process

Science.gov (United States)

Cuadros, Sara; Dell'Amico, Luca

2017-01-01

Abstract Reported herein is a light‐triggered organocatalytic strategy for the desymmetrization of achiral 2‐fluoro‐substituted cyclopentane‐1,3‐diketones. The chemistry is based on an intermolecular aldol reaction of photochemically generated hydroxy‐o‐quinodimethanes and simultaneously forges two adjacent fully substituted carbon stereocenters, with one bearing a stereogenic carbon–fluorine unit. The method uses readily available substrates, a simple chiral organocatalyst, and mild reaction conditions to afford an array of highly functionalized chiral 2‐fluoro‐3‐hydroxycyclopentanones. PMID:28746742

In Silico Medicine: Social, Technological and Symbolic Mediation

Directory of Open Access Journals (Sweden)

Annamaria Carusi

2016-06-01

Full Text Available In silico medicine is still forging a road for itself in the current biomedical landscape. Discursively and rhetorically, it is using a three-way positioning, first, deploying discourses of personalised medicine, second, extending the 3Rs from animal to clinical research, and third, aligning its methods with experimental methods. The discursive and rhetorical positioning in promotions and statements of the programme gives us insight into the sociability of the scientific labour of advancing the programme. Its progress depends on complex social, institutional and technological conditions which are not external to its epistemology, but intricately interwoven with it. This article sets out to show that this is the case through an analysis of the process of computational modelling that is at the core of its epistemology. In this paper I show that the very notion of ‘model’ needs to be re-thought for in silico medicine (as indeed, for most forms of computational modelling, and propose a replacement, in the form of the ‘Model-Simulation-Experiment-System’ or MSE-system, which is simultaneously an epistemological, social and technological system. I argue that the MSE-system is radically mediated by social relations, technologies and symbolic systems. We need now to understand how such mediations operate effectively in the construction of robust MSE-systems.

Reduction of Milling Time by Using CAQ Technologies

Directory of Open Access Journals (Sweden)

Zaujec Rudolf

2016-09-01

Full Text Available The paper is focused on reducing machining time by using 3D optical scanner of ATOS Triplescan II. Workpiece was a forging die, which was renovated by hard facing. The contribution deals with comparing the CAM simulation of roughing process according to the STL model imported from ATOS, and simulation without thus-defined workpiece. The results indicate a significant improvement of machining time based on CAQ technology and usage of the ATOS device for measuring the errors of weld deposit.

The investigation of the FM heavy forging process by the Moiré method. Part II: Consecutive reduction results

NARCIS (Netherlands)

Wang, S.L.; Cao, Q.X.

1994-01-01

In part I of this work (preceding paper), single-reduction results on the FM forging process were reported. In the work reported in this paper, the cavity closing laws of the consecutive reduction process were investigated, the appropriate turn-over and feed procedure being obtained, along with the

Grain size control method for the nozzles of AP1000 primary coolant pipes

Energy Technology Data Exchange (ETDEWEB)

Wang, Shenglong [State Key Laboratory for Advanced Metals and Materials, University of Science & Technology Beijing, Beijing 100083 (China); Sun, Yanhui [Collaborative Innovation Center of Steel Technology, University of Science & Technology Beijing, Beijing 100083 (China); Yang, Bin, E-mail: byang@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, University of Science & Technology Beijing, Beijing 100083 (China); Collaborative Innovation Center of Steel Technology, University of Science & Technology Beijing, Beijing 100083 (China); Zhang, Mingxian [State Key Laboratory for Advanced Metals and Materials, University of Science & Technology Beijing, Beijing 100083 (China)

2017-04-01

Highlights: • Design a new forging technology for AP1000 primary coolant pipe. • Method combining FEM and scale-down experiments is adopted. • The grain size and distribution in simulation and experiment are consistent. • Get optimal forging parameters for production guiding. - Abstract: AP1000 primary coolant pipe is made of 316LN austenitic stainless steel. It is a large special-shaped pipe manufactured by integral forging technology. Owing to non-uniform temperature and deformation during forging, coarse grains often occur in the boss sections of the pipe especially in the nozzles’ parts. In the present study, a new forging technology was proposed to control the grain size. The finite element method was used to optimize the forging speed and friction coefficient, then the scale-down experiments were performed for comparison. The forging speed is suggested to be less than 20 mm/s, and effective lubricants should be used to decrease the friction coefficient. The errors of the grain size between the experiment and simulation are less than 20%.

Grain size control method for the nozzles of AP1000 primary coolant pipes

International Nuclear Information System (INIS)

Wang, Shenglong; Sun, Yanhui; Yang, Bin; Zhang, Mingxian

2017-01-01

Highlights: • Design a new forging technology for AP1000 primary coolant pipe. • Method combining FEM and scale-down experiments is adopted. • The grain size and distribution in simulation and experiment are consistent. • Get optimal forging parameters for production guiding. - Abstract: AP1000 primary coolant pipe is made of 316LN austenitic stainless steel. It is a large special-shaped pipe manufactured by integral forging technology. Owing to non-uniform temperature and deformation during forging, coarse grains often occur in the boss sections of the pipe especially in the nozzles’ parts. In the present study, a new forging technology was proposed to control the grain size. The finite element method was used to optimize the forging speed and friction coefficient, then the scale-down experiments were performed for comparison. The forging speed is suggested to be less than 20 mm/s, and effective lubricants should be used to decrease the friction coefficient. The errors of the grain size between the experiment and simulation are less than 20%.

A Study on Structural, Corrosion, and Sensitization Behavior of Ultrafine and Coarse Grain 316 Stainless Steel Processed by Multiaxial Forging and Heat Treatment

Science.gov (United States)

Kiahosseini, Seyed Rahim; Mohammadi Baygi, Seyyed Javad; Khalaj, Gholamreza; Khoshakhlagh, Ali; Samadipour, Razieh

2018-01-01

Cubic specimens from AISI 316 stainless steel were multiaxially forged to 15 passes and annealed at 1200 °C for 1, 2, and 3 h and finally sensitized at 700 °C for 24 h. Examination of samples indicated that the hardness of the annealed samples was reduced from 153 to 110, 81, and 74 HV for as-received sample and under 1, 2, and 3 h of annealing, and increased from 245 to 288 HV for samples forged at 3 and 7 passes. However, no significant changes were observed in a large number of passes and at about 300 HV. Degree of sensitization of samples was increased to approximately 27.3% at 3-h annealing but reduced to 1.23% by 15 passes of MF. The potentiodynamic polarization test shows that the breakdown potentials decreased with annealing time from 0.6 to - 102 (mV/SCE) for as-received and 3-h annealed specimen. These potentials increased to approximately - 16.5 mV with the increase in MF passes to 15. These observations indicated that the chromium carbide deposition affects Cr-depleted zone, which can subsequently affect the degree of sensitization and pitting corrosion resistance of AISI 316 austenitic stainless steel.

Study on Pot Forming of Induction Heater Type Rice Cookers by Forging Cast Process

Science.gov (United States)

Ohnishi, Masayuki; Yamaguchi, Mitsugi; Ohashi, Osamu

This paper describes a study result on pot fabrication by the forging cast process of stainless steel with aluminum. Rice cooked with the new bowl-shaped pot for the induction heater type rice cookers is better tasting than rice cooked with the conventional cylindrical one, due to the achievement of better heat conduction and convection. The conventional pot is made of the clad sheet, consisting of stainless steel and aluminum. However, it is rather difficult to form a bowl shape from the clad sheet, primarily due to the problem of a material spring back. The fabrication of a new type of a pot was made possible by means of the adoption of a forging cast process instead of the clad sheet. In this process, iron powder is inserted between stainless steel and aluminum in order to alleviate the large difference on the coefficient of expansion between each material. It was made clear that the application of two kinds of iron particle, namely 10 μm size powder on the stainless steel side and 44 μm on the aluminum side, enables the joints to become strong enough. The joint strength of the new pot by this fabrication process was confirmed by the tests of the shear strength and the fatigue tests together with the stress analysis.

Forging Fluorine-Containing Quaternary Stereocenters by a Light-Driven Organocatalytic Aldol Desymmetrization Process.

Science.gov (United States)

Cuadros, Sara; Dell'Amico, Luca; Melchiorre, Paolo

2017-09-18

Reported herein is a light-triggered organocatalytic strategy for the desymmetrization of achiral 2-fluoro-substituted cyclopentane-1,3-diketones. The chemistry is based on an intermolecular aldol reaction of photochemically generated hydroxy-o-quinodimethanes and simultaneously forges two adjacent fully substituted carbon stereocenters, with one bearing a stereogenic carbon-fluorine unit. The method uses readily available substrates, a simple chiral organocatalyst, and mild reaction conditions to afford an array of highly functionalized chiral 2-fluoro-3-hydroxycyclopentanones. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Forging New, Non-traditional Partnerships Among Physicists, Teachers and Students

Energy Technology Data Exchange (ETDEWEB)

Bardeen, Marjorie [Fermilab; Adams, Mark [Illinois U., Chicago; Wayne, Mitchell [Notre Dame U.; Karmgard, Dan [Notre Dame U.; Goussiou, Anna [Washington U., Seattle

2017-05-02

The QuarkNet collaboration has forged new, nontraditional relationships among particle physicists, high school teachers and their students. QuarkNet provides professional development for teachers and creates opportunities for teachers and students to engage in particle physics data investigations and join research teams. Embedded in the U.S. particle research community, QuarkNet leverages the nature of particle physics research—the long duration of the experiments with extensive lead times, construction periods, and data collection and analysis periods. QuarkNet is patterned after the large collaborations with a central management infrastructure and a distributed workload across university- and lab-based research groups. We describe the important benefits of the QuarkNet outreach program that flow to university faculty and present successful strategies that others can adapt for use in their countries.

Forging New Cocoa Keys: The Impact of Unlocking the Cocoa Bean’s Genome on Pre-harvest Food Safety

Science.gov (United States)

Forging New Cocoa Keys: The Impact of Unlocking the Cocoa Bean’s Genome on Pre-harvest Food Safety David N. Kuhn, USDA ARS SHRS, Miami FL Sometimes it's hard to see the value and application of genomics to real world problems. How will sequencing the cacao genome affect West African farmers? Thi...

Microstructural heterogeneities and fatigue anisotropy of forged steels

International Nuclear Information System (INIS)

Pessard, Etienne; Morel, Franck; Verdu, Catherine; Flaceliere, Laurent; Baudry, Gilles

2011-01-01

Highlights: → Tomography result: fibering is composed of non-metallic inclusions bands. → Elongated inclusions decreases the: ductility, fracture toughness and fatigue limit. → Cracks initiate from both inclusion clusters and from the bainitic matrix. → The classical self-heating method does not predict the effect of the inclusions. - Abstract: In this study, various experimental methods are employed to determine the anisotropic fatigue behavior of a 25MnCrSiVB6 forged steel (Metasco MC). This material has a bainitic microstructure and contains many elongated non-metallic inclusions in the rolled direction, which are grouped into clusters. Specimens with different orientations relative to the rolling direction have been extracted from a hot rolled bar and the ability of certain experimental techniques to capture the fatigue anisotropy has been tested. Results obtained from monotonic tensile tests and Charpy impact tests show that the material has isotropic fracture strength and anisotropic ductility. The influence of the 'inclusion clusters' is clearly demonstrated via observation of the fracture surfaces. Concerning the fatigue behavior, results from a classical staircase experimental procedure are compared to results from self-heating fatigue tests. For specimens orientated at 0 o relative to the rolled direction, microcrack initiation is controlled by the material matrix and the prediction of the fatigue strength with the self-heating method has been observed to be correct. For specimens orientated at 45 o and 90 o , the elongated manganese sulfide inclusion clusters are the origin of crack initiation and the fatigue strength drops significantly. For this case, it appears that the self-heating method has difficulty predicting the fatigue behavior.

Microstructural heterogeneities and fatigue anisotropy of forged steels

Energy Technology Data Exchange (ETDEWEB)

Pessard, Etienne, E-mail: etienne.pessard@angers.ensam.fr [LAMPA, Arts et Metiers ParisTech Angers, 2 Bd du Ronceray, 49035 Angers Cedex 01 (France); Morel, Franck [LAMPA, Arts et Metiers ParisTech Angers, 2 Bd du Ronceray, 49035 Angers Cedex 01 (France); Verdu, Catherine [MATEIS, INSA-Lyon, Universite de Lyon, 25 Av Jean Capelle, 69621 Villeurbanne Cedex (France); Flaceliere, Laurent; Baudry, Gilles [CREAS - ASCOMETAL, BP 70045, 57301 Hagondange (France)

2011-11-25

Highlights: {yields} Tomography result: fibering is composed of non-metallic inclusions bands. {yields} Elongated inclusions decreases the: ductility, fracture toughness and fatigue limit. {yields} Cracks initiate from both inclusion clusters and from the bainitic matrix. {yields} The classical self-heating method does not predict the effect of the inclusions. - Abstract: In this study, various experimental methods are employed to determine the anisotropic fatigue behavior of a 25MnCrSiVB6 forged steel (Metasco MC). This material has a bainitic microstructure and contains many elongated non-metallic inclusions in the rolled direction, which are grouped into clusters. Specimens with different orientations relative to the rolling direction have been extracted from a hot rolled bar and the ability of certain experimental techniques to capture the fatigue anisotropy has been tested. Results obtained from monotonic tensile tests and Charpy impact tests show that the material has isotropic fracture strength and anisotropic ductility. The influence of the 'inclusion clusters' is clearly demonstrated via observation of the fracture surfaces. Concerning the fatigue behavior, results from a classical staircase experimental procedure are compared to results from self-heating fatigue tests. For specimens orientated at 0{sup o} relative to the rolled direction, microcrack initiation is controlled by the material matrix and the prediction of the fatigue strength with the self-heating method has been observed to be correct. For specimens orientated at 45{sup o} and 90{sup o}, the elongated manganese sulfide inclusion clusters are the origin of crack initiation and the fatigue strength drops significantly. For this case, it appears that the self-heating method has difficulty predicting the fatigue behavior.

The study of high-boron steel and high-boron cast iron used for shield

International Nuclear Information System (INIS)

Pan Xuerong; Lu Jixin; Wen Yaozeng; Wang Zhaishu; Cheng Jiantin; Cheng Wen; Shun Danqi; Yu Jinmu

1996-12-01

The smelting, forging, heat-treatment technology and the mechanical properties of three kinds of high-boron steels (type 1: 0.5% boron; type 2: 0.5% boron and 4% or 2% nickel; type 3: 0.5% boron, 0.5% nickel and 0.5% molybdenum) were studied. The test results show that the technology for smelting, forging and heat-treatment (1050 degree C/0.5 h water cooled + 810 degree C/1 h oil cooled) in laboratory is feasible. Being sensitive to notch, the impact toughness of high-boron steel type 1 is not steady and can not meet the technology requirements on mechanical properties. The mechanical properties of both high-boron steel type 2 and type 3 can meet the technological requirements. The smelting technology of high-boron casting iron containing 0.5% boron was researched. The tests show that this casting iron can be smelted in laboratory and its properties can basically satisfy the technology requirements. (10 refs., 6 figs., 11 tab.)

Forging partnerships between rural women with chronic conditions and their health care providers.

Science.gov (United States)

Cudney, Shirley; Weinert, Clarann; Kinion, Elizabeth

2011-03-01

Successful adaptation to chronic illness is enhanced by active client-health care provider partnerships. The purposes of this article are to (a) examine the health care partnership needs of western rural women with chronic illness who participated in a computer-based support and education project, (b) describe how the role of the women in the partnership can be maximized by the use of a personal health record and improving health literacy, and (c) discuss ways health care providers can enhance their role in the partnership by careful listening and creating environments conducive to forging productive client-provider partnerships.

Development and production of nuclear valves. Forging and welding. Pt. 2

International Nuclear Information System (INIS)

Bernal Castro, J.B.; Perez, J.C.; Labonia, R.N.

1987-01-01

The first part of this work deals with the obtainment of the austenitic stainless steel DIN 1.4541 (AISI 321) stabilized titanium for Atucha II nuclear valves. The second part presented herein, continued with the development process and part of the production of the bodies' forging and valves leads. This development has been also carried out in the country and a detailed set up of the process with its corresponding Inspection and Assay Program was needed. The last part of this stage has been initiated at the welding process, so it was necessary to develop specific welding procedures to qualify them and use the equipment specially applied to this requirement. The set of assays and criteria certification for the qualifications is presented. (Author)

Optimum schedules of difficult-to-form heat-resistant alloys forging

International Nuclear Information System (INIS)

Majzengel'ter, V.A.; Shuvalov, A.A.; Perevozov, A.S.

2000-01-01

The process of manufacturing half finished discs for hydroturbine engines from heat resistant difficulty deformed nickel, iron-nickel and cobalt alloys (EI435, EI868, VZh145-ID, EK79-ID, EK152-ID, EI826, EP648-VI) is described. The recommendations on the modes of forging the single-phase nonaging and double phase aging alloys are developed. The conclusion is made, that the first compressions of ingots shoved be accomplished by small press runs. The subsequent compressions should constituted not less than 8% during one run. The total compression of the ingot during one heating should be within the concrete alloy properties. With the purpose of obtaining uniform fine-grain structure the ingot heating during the last manufacturing cycle should be accomplished within the range of 1100-1130 deg C for the majority of heat resistant alloys [ru

A planning framework for transferring building energy technologies

Energy Technology Data Exchange (ETDEWEB)

Farhar, B C; Brown, M A; Mohler, B L; Wilde, M; Abel, F H

1990-07-01

Accelerating the adoption of new and existing cost-effective technologies has significant potential to reduce the energy consumed in US buildings. This report presents key results of an interlaboratory technology transfer planning effort in support of the US Department of Energy's Office of Building Technologies (OBT). A guiding assumption for planning was that OBT's R D program should forge linkages with existing programs whose goals involved enhancing energy efficiency in buildings. An ad hoc Technology Transfer Advisory Group reviewed the existing analysis and technology transfer program, brainstormed technology transfer approaches, interviewed DOE program managers, identified applicable research results, and developed a framework that management could use in deciding on the best investments of technology transfer resources. Representatives of 22 organizations were interviewed on their views of the potential for transferring energy efficiency technologies through active linking with OBT. The report describes these programs and interview results; outlines OBT tools, technologies, and practices to be transferred; defines OBT audiences; identifies technology transfer functions and presents a framework devised using functions and audiences; presents some 60 example technology transfer activities; and documents the Advisory Group's recommendations. 37 refs., 3 figs., 12 tabs.

The Pastoral Power of Technology. Rethinking Alienation in Digital Culture

Directory of Open Access Journals (Sweden)

Katarina Giritli Nygren

2012-05-01

Full Text Available The purpose of this paper is to bring Foucault’s elaboration on ‘the pastoral modalities of power’ into play in order to rethink alienation in digital culture. Pastoral power is not displacing other conceptions of power, but provides another level of analysis involved in the forging of reasonable responsible subjects willing and able to sustain other conceptions of power. We will draw particularly on the early writings of Marx and the more recent poststructuralist developments concerning hegemony and superstructure in relation to technology. Technology as such is analysed in terms of repercussions of ‘design of the machine’ in industrial technological contexts and ‘design of digital culture’ in digital technological contexts. Pastoral power not only directs our focus to the making of technologies, but also to the making of individuals capable of taking on the responsibilities of technologies. This means that it is necessary to take on the notion of effective power of ideologies and their material reality.

Italian high technology shows its wares at CERN

CERN Multimedia

Maximilien Brice

2005-01-01

Italian industry held an exhibition at CERN on 14-17 November with 26 firms displaying innovative technological developments. In particular it featured categories such as mechanics, high-vacuum technologies, electronics for detectors, and electric and civil engineering. The exhibition was inaugurated in the presence of Guido Possa, vice-minister for education, universities and research. The event was organized by Sandro Centro, INFN researcher and Industrial Liaison Officer at CERN, along with Federico Ferrini, scientific officer for International Organizations of Geneva and the Italian Chamber of Commerce in Switzerland

An Assessment of the Ductile Fracture Behaviour of Hot Isostatically Pressed and Forged 304L Stainless Steel

OpenAIRE

Cooper, Adam; Smith, R. J.; Sherry, Andrew

2017-01-01

Type 300 austenitic stainless steel manufactured by hot isostatic pressing (HIP) has recently been shown to exhibit subtly different fracture behavior from that of equivalent graded forged steel, whereby the oxygen remaining in the component after HIP manifests itself in the austenite matrix as nonmetallic oxide inclusions. These inclusions facilitate fracture by acting as nucleation sites for the initiation, growth, and coalescence of microvoids in the plastically deforming austenite matrix....

The Effect of Forging Variables on the Supersolvus Heat-Treatment Response of Powder-Metallurgy Nickel-Base Superalloys

Science.gov (United States)

2014-12-01

AFRL-RX-WP-JA-2015-0160 THE EFFECT OF FORGING VARIABLES ON THE SUPERSOLVUS HEAT-TREATMENT RESPONSE OF POWDER - METALLURGY NICKEL-BASE SUPERALLOYS... POWDER - METALLURGY NICKEL- BASE SUPERALLOYS (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR...treatment (SSHT) of two powder - metallurgy , gamma–gamma prime superalloys, IN-100 and LSHR, was established. For this purpose, isothermal, hot

Effect of nickel addition on mechanical properties of powder forged Fe-Cu-C

Science.gov (United States)

Archana Barla, Nikki

2018-03-01

Fe-Cu-C system is very popular in P/M industry for its good compressibility and dimensional stability with high strength. Fe-Cu-C is a structural material and is used where high strength with high hardness is required. The composition of powder metallurgy steel plays a vital role in the microstructure and physical properties of the sintered component. Fe-2Cu-0.7C-Ni alloy with varying nickel composition (0%, 0.5%, 1.0%, 1.5%, 2.0%, and 3.0%) wt. % was prepared by powder metallurgy (P/M) sinter forging process. The present work discuss the effect of varying nickel content on microstructure and mechanical properties.

α-Linalool - a marker compound of forged/synthetic sweet basil (Ocimum basilicum L.) essential oils.

Science.gov (United States)

Radulović, Niko S; Blagojević, Polina D; Miltojević, Ana B

2013-10-01

Ocimum basilicum L. (sweet basil) is known to occur as several chemotypes or cultivars that differ in their essential oil composition. The surprising discovery of 3,7-dimethylocta-1,7-dien-3-ol, the rare α isomer of the well-known monoterpene alcohol β-linalool (3,7-dimethylocta-1,6-dien-3-ol), in samples of Serbian basil oil provoked an investigation of the origin of α-linalool in these samples. Three scenarios were considered, namely (a) the existence of a new natural chemotype, (b) an artefactual formation during the isolation procedure and (c) the case of a synthetic/forged oil. Noteworthy amounts (15.1-16.9%) of pure α-linalool were isolated from a commercial sample of basil oil, and detailed spectral analyses (MS, IR, (1) H and (13) C NMR) unequivocally confirmed its identity. The analysis by GC and GC/MS of an additional 20 samples of different O. basilicum oils commercially available on the Serbian market or isolated from plant material cultivated in Serbia resulted in the identification of 149 compounds. The obtained compositional data were compared using multivariate statistical analysis to reveal the possible existence of a new basil chemotype. The results of the chemical and statistical analyses give more pro arguments for the synthetic/forged oil hypothesis and suggest that α-linalool could be used as a marker compound of such O. basilicum oils. © 2013 Society of Chemical Industry.

Olivier Caïra, Jeux de rôle. Les forges de la fiction

Directory of Open Access Journals (Sweden)

Antoine Dauphragne

2010-06-01

Full Text Available Les forges de la fiction, d’Olivier Caïra, est à ranger parmi les rares ouvrages francophones en sciences humaines s’attachant au jeu de rôles. L’ouvrage en propose une analyse fine et dynamique centrée sur la pratique des joueurs. La démarche annoncée, qui entend proposer un texte accessible aussi bien aux rôlistes qu’aux universitaires, semble renvoyer autant à un souci de clarté qu’au profil de l’auteur. Olivier Caïra est sociologue ; ses travaux portent sur l’industrie du divertissement e...

Influence of sulphur and phosphorus impurities on ductility of 25Kh2NMFA steel during forging

International Nuclear Information System (INIS)

Onishchenko, A.K.

1989-01-01

Using cylindrical samples of the 25Kh2NMFA steel with sulfur and phosphorus content in the range of 0.001-0.030%, tensile test with the rate of deformation 10 -3 s -1 at the temperatures of 800-1200 deg C has been conducted. Analysis of fracture foci and plasticity diagrams has shown, that to ensure ductility during forging and high mechanical properties, the content of sulfur and phosphorus impurities in the 25Kh2NMFA steel must not exceed 0.015%

Managing threats from emerging technologies: can safeguards show the way?

International Nuclear Information System (INIS)

Leffer, Teri N.

2014-01-01

The system of international nuclear safeguards implemented by the International Atomic Energy Agency (IAEA) is primarily a means of verification of states’ commitments under various legal instruments, principally the Nuclear Non‑Proliferation Treaty (NPT), to utilize controlled nuclear fission for peaceful purposes only. However, the safeguards system can also be seen as a mechanism through which states acted to reduce the threat posed by a new technology that had a transformative impact on existing national security paradigms when it emerged in the twentieth century. In the twenty‑first century, new technologies with equally profound national security implications are emerging. These include biotechnology and synthetic biology, nano technology, information technology, cognitive science, robotics and artificial intelligence. Throughout its history, the safeguards system has evolved to accommodate new technologies, new undertakings and new threats. Because multiple emerging technologies now constitute potential national security threats, it is appropriate to consider whether and how the lessons and successes of the safeguards system, including its capacity to evolve in response to changing requirements, could be leveraged to mitigate the threat posed by these new technologies. This paper addresses the possibility of re‑imagining safeguards in a way that makes them applicable to a broader range of technology‑based threats without compromising their effectiveness for their original purpose.

Process parameter influence on Electro-sinter-forging (ESF) of titanium discs

DEFF Research Database (Denmark)

Cannella, Emanuele; Nielsen, Chris Valentin; Bay, Niels

Electro-sinter-forging (ESF) is an innovative sintering process based on the principle of electrical Joule heating. The electrical current is flowing through the powder compact, which is under mechanical pressure. As compared to conventional sintering [1] and spark plasma sintering [2], the main...... advantages are the decreased sintering time and high relative density [3]. Near net-shape components can be manufactured and post-removal processing is limited to surface polishing. The present work is focused on analysing the influence of the main process parameters, namely compacting pressure, sintering...... time and electrical current density, on the final density of a disc sample made from commercially pure titanium powder. The maximum achieved relative density was 94% of the bulk density of pure titanium. The density estimation was carried out by using both Archimedes’ and 3D scanning....

Showing and telling : film heritage institutes and their performance of public accountability

NARCIS (Netherlands)

de Klerk, N.H.

2015-01-01

This PhD expands on 12 previously published film historical and -archival articles and essays. An extensive introductory text was written to string these articles and essays together and forge them into an argument for improving the performance of film heritage institutes vis-a-vis the public. In

A new casting defect healing technology

Energy Technology Data Exchange (ETDEWEB)

Hodge, E.S.; Reddoch, T.W. [ForMat Industries, Inc., Knoxville, TN (United States); Viswanathan, S. [Oak Ridge National Lab., TN (United States)

1997-01-01

A new technology is presented for healing of defects in 356 aluminium alloys that provides economic upgrading of these cast alloys. It uses pneumatic isostatic forging (PIF) to produce high quality Al alloys products with enhanced mechanical properties uniform throughout the part, allowing higher design allowables and increased usage of Al alloy castings. The fundamental mechanism underlying PIF is a single mode plastic deformation process that uses isostatic application of pressures for 10-30 seconds at temperature. The process can be integrated in-line with other production operations, i.e., using the latent heat from the previous casting step. Results of applying the PIF process indicate lower cost and significant improvement in mechanical properties that rival and often exceed corresponding properties of other technologies like hot isostatic pressing and related processes. This process offers many advantages that are described in this paper in addition to presenting case histories of property enhancement by PIF and the mechanism responsible for property enhancement.

An investigation of deformed microstructure and mechanical properties of Zircaloy-4 processed through multiaxial forging

Energy Technology Data Exchange (ETDEWEB)

Fuloria, Devasri; Nageswararao, P. [Department of Metallurgical and Materials Engineering & Centre of Nanotechnology, IIT Roorkee, Roorkee 247667 (India); Jayaganthan, R., E-mail: rjayafmt@iitr.ernet.in [Department of Metallurgical and Materials Engineering & Centre of Nanotechnology, IIT Roorkee, Roorkee 247667 (India); Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036 (India); Jha, S. [Nuclear Fuel Complex Limited, Hyderabad 501301 (India); Srivastava, D. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 40085 (India)

2016-04-15

In the present work, the mechanical behavior of Zircaloy-4 subjected to various deformation strains by multiaxial forging (MAF) at cryogenic temperature (CT) was investigated. The alloy was strained up to different number of cycles, viz., 6 cycles, 9 cycles, and 12 cycles at cumulative strains of 2.96, 4.44, and 5.91, respectively. The mechanical properties of the alloy were investigated by performing the universal tensile test and the Vickers hardness test. Both the test showed improvement in the ultimate tensile strength and hardness value by 51% and 26%, respectively, at the highest cumulative strain of 5.91. The electron backscattered diffraction (EBSD) measurement and transmission electron microscopy (TEM) were used for analyzing the deformed microstructure. The microstructures of the alloy underwent deformation at various cumulative strains/cycles showed grain refinement with the evolution of shear and twin bands that were highest for the alloy deformed at the highest number of cycles. The effective grain refinement was due to twins formation and their intersection, which led to the improvement in mechanical properties of the MAFed alloy, as observed in the present work. - Highlights: • Zircaloy-4 was subjected to MAF at cryogenic temperature. • Microstructural evolution was studied through EBSD and TEM. • Deformed microstructure was marked with various types of twinning and shear banding. • Twins formations are responsible for effective grain refinement and enhanced mechanical properties.

Microstructure of Semi-Solid 6063 Alloy Fabricated by Radial Forging Combined with Unidirectional Compression Recrystallization and Partial Melting Process

Directory of Open Access Journals (Sweden)

Wang Yongfei

2017-01-01

Full Text Available Radial forging combined with unidirectional compression (RFCUM is introduced in recrystallization and partial melting (RAP to fabricate semi-solid 6063 aluminum alloy, which can be defined as a process of RFCUM-RAP. In this study, the microstructures of semi-solid 6063 alloy prepared by semi-solid isothermal treatment (SSIT and RFCUM-RAP processes are investigated. The results show that, the solid grains of semi-solid alloy prepared by SSIT are large and irregular. However, solid grains of semi-solid billet prepared by RFCUC-RAP are fine and spherical. Additionally, during RFCUC-RAP process, with the increase of isothermal holding time, the shape of solid grain is more and more spherical, but the size of solid grain is gradually increased. To obtain ideal semi-solid microstructure, the optimal isothermal holding temperature and time are 630 °C and 5~10 min, respectively.

Energy-efficiency in inductive heating of forging ingots; Energieeffizienz bei der induktiven Erwaermung von Schmiedebloecken

Energy Technology Data Exchange (ETDEWEB)

Padberg, Michael; Doetsch, Erwin [ABP Induction Systems, Dortmund (Germany)

2012-03-15

The continuously increasing importance of the CO{sub 2} balance and of conservation of resources is resulting in ever greater demands for high energy-efficiency in the process used for heating of forging ingots. Plant and process engineering play roles of parallel significance in the fulfillment of these requirements, and this article focuses on both in equal degree. The shares of the individual components in the overall energy consumption of an induction heating installation are therefore firstly determined, and their respective potentials for optimization then discussed. The quality of the heating process itself, and its optimum design for reduction of energy consumption, are then examined. (orig.)

A brief history of Forging New Frontiers, the annual conference of the Injury Free Coalition for Kids.

Science.gov (United States)

Johnson, Estell Lenita; Barlow, Barbara

2016-10-01

The Injury Free Coalition for Kids Annual Conference has contributed to the dissemination of information pertaining to the development of the field of injury prevention. A content analysis was completed using conference agendas used during the span of 2005-2015, finding that more than 398 presentations covering a wide variety of injuries have taken place. Published work has appeared in the Journal of Trauma and there has been recognition of people who have contributed to the development of the field. Forging New Frontiers is a valuable tool for attendees to exchange information about injury prevention.

Cold forming of aluminium - State of the art

DEFF Research Database (Denmark)

Bay, Niels

1997-01-01

The ongoing development of cold forging technology has been manifested lately by the increasing application of components in cold forged aluminium alloys. Applying precipitation hardening alloys components with great strength/weight ratio can be produced with a strength comparable...... to that of unalloyed steel. After description of the different types of alloys and their individual properties and applications, the special requirements for tool design by cold forging in aluminium is discussed. Finally, a large number of industrial examples on cold forged aluminium components are presented. (C) 1997...

Occupational noise exposure in small scale hand tools manufacturing (forging) industry (SSI) in Northern India.

Science.gov (United States)

Singh, Lakhwinder Pal; Bhardwaj, Arvind; Deepak, K K; Bedi, Raman

2009-08-01

Occupational noise has been recognized as hazardous for the human beings. A high noise level in forging shops is considered to lower the labour productivity and cause illness however occupational noise is being accepted as an integral part of the job. The present study has been carried out in 5 small scale hand tool forging units (SSI) of different sizes in Northern India in Punjab. Noise levels at various sections were measured. OSHA norms for hearing conservation has been incorporated which includes an exchange rate of 5 dB (A), criterion level at 90 dB (A), criterion time of 8 h, threshold level=80 dB (A), upper limit=140 dB (A) and with F/S response rate. Equivalent sound pressure level (L(eq)) has been measured in various sections of these plants. Noise at various sections like hammer section, cutting presses, punching, grinding and barrelling process was found to be >90 dB (A), which is greater than OSHA norms. A cross-sectional study on the basis of questionnaire has been carried out. The results of which revealed that 68% of the workers are not wearing ear protective equipments out of these 50% were not provided with PPE by the company. About 95% of the workers were suffering speech interference though high noise annoyance was reported by only 20%. It has been established that the maximum noise exposure is being taken by the workers as they are working more than 8h a day for six days per week. More than 90% workers are working 12 to 24 h over time per week which lead to very high noise exposure i.e. 50 to 80% per week higher than exposure time/week in USA or European countries(15, 16)).

Technology Takes Coaching to Scale: Investing in Innovation Grantees Show How It's Done

Science.gov (United States)

Breslow, Nicole

2017-01-01

In recent years, there has been increasing interest in the use of video and other technology tools to support professional learning. A growing body of evidence shows how these tools are improving teachers' practice (Borko, Jacobs, Eiteljorg, & Pittman, 2008; Grant & Kline, 2010; van Es & Sherin, 2010). However, there has been less…

THE ROLE OF THE COMPETITION POLICY IN FORGING THE EUROPEAN COMMON MARKET

Directory of Open Access Journals (Sweden)

Radu-Cristian Muşetescu

2008-12-01

Full Text Available The forging of the Single Market represents the most important dimension of the first pillar of the European Union, which is the European Community. It can be argued that, as compared to the other two pillars (the Common Foreign and Security Policy and the Police and Judicial Cooperation in the Criminal Matters, it has the most powerful impact on the welfare of European citizens. The European policy makers define however the Internal Market as not only an economic area where there are no more state-imposed barriers in the path of the freedom of movement of goods and services at the borders of the member-states but also a single business environment where there are a single currency, coordinated economic policies as well as homogeneous business practices of private undertakings. In this process, despite a large set of common policies, the competition policy has reached the status of the building block of the Common Market.

Weldability Characteristics of Sintered Hot-Forged AISI 4135 Steel Produced through P/M Route by Using Pulsed Current Gas Tungsten Arc Welding

Science.gov (United States)

Joseph, Joby; Muthukumaran, S.; Pandey, K. S.

2016-01-01

Present investigation is an attempt to study the weldability characteristics of sintered hot-forged plates of AISI 4135 steel produced through powder metallurgy (P/M) route using matching filler materials of ER80S B2. Compacts of homogeneously blended elemental powders corresponding to the above steel were prepared on a universal testing machine (UTM) by taking pre-weighed powder blend with a suitable die, punch and bottom insert assembly. Indigenously developed ceramic coating was applied on the entire surface of the compacts in order to protect them from oxidation during sintering. Sintered preforms were hot forged to flat, approximately rectangular plates, welded by pulsed current gas tungsten arc welding (PCGTAW) processes with aforementioned filler materials. Microstructural, tensile and hardness evaluations revealed that PCGTAW process with low heat input could produce weldments of good quality with almost nil defects. It was established that PCGTAW joints possess improved tensile properties compared to the base metal and it was mainly attributed to lower heat input, resulting in finer fusion zone grains and higher fusion zone hardness. Thus, the present investigation opens a new and demanding field in research.

Characterization of residual stresses in heat treated Ti-6Al-4V forgings by machining induced distortion

Directory of Open Access Journals (Sweden)

Werner E.

2010-06-01

Full Text Available To provide a solid base for improved material exploitation in dimensioning calculations it is necessary to determine the stress state in the part prior to service loading. In order to achieve higher material strength at elevated temperatures, the surface temperature gradient with respect to time has to be sufficiently high during heat treatment. This results in non-negligable residual stresses that can reduce the allowable load level upon which yielding occurs. For titanium alloys there are two common heat treatments, namely solution treatment and mill annealing. The latter one is the method of choice within the presented project. Mill annealing is utilized in order to significantly reduce the residual stresses in the parts without loosing much of the improved strength at elevated temperatures. Quantification of residual stresses is done by solving an inverse problem. From the measurement of distortion, induced by dividing the investigated part, the residual stress state can be calculated via analytical modeling or correlation with finite element models. To assure a minimum perturbation of the residual stress state during specimen production, dividing of the part is accomplished by electric discharge machining. The parts of interest are v-shaped prisms with a length of approximatly 450 mm and a thickness in the cross sectional area from about 20 mm to 45 mm. Figure 1(a shows the forged part and 1(b the dimensions of the cross section in millimeters as well as the material properties considered in the finite element model. The heat exchange between the part and the environment is modelled as heat transfer by convection superimposed with heat radiation. Since the parts are exposed to air during forging and heat treatment, the surface develops a strongly adhesive oxide layer, the so called alpha-case. After forging the parts are cooled in air and heat treated at a temperature of 720° C for a duration of 120 min. Subsequent air cooling and

Essaying the mechanical hypothesis: Descartes, La Forge, and Malebranche on the formation of birthmarks.

Science.gov (United States)

Wilkin, Rebecca M

2008-01-01

This essay examines the determination by Cartesians to explain the maternal imagination's alleged role in the formation of birthmarks and the changing notion of monstrosity. Cartesians saw the formation of birthmarks as a challenge through which to demonstrate the heuristic capacity of mechanism. Descartes claimed to be able to explain the transmission of a perception from the mother's imagination to the fetus' skin without having recourse to the little pictures postulated by his contemporaries. La Forge offered a detailed account stating that the failure to explain the maternal imagination's impressions would cast doubt on mechanism. Whereas both characterized the birthmark as a deformation or monstrosity in miniature, Malebranche attributed a role to the maternal imagination in fashioning family likenesses. However, he also charged the mother's imagination with the transmission of original sin.

Development of cask body integrated with bottom plate

International Nuclear Information System (INIS)

Yoshida, Takuji; Sasaki, Tomoharu; Koyama, Yoichi; Kumagai, Yasuyuki; Watanabe, Yuichi; Takasa, Seiju

2017-01-01

The main parts of a metal cask for storage and transport of spent nuclear fuel consists of main body, neutron shield material and external cylinder. The forged main body has been manufactured as a cup shape by welding of 'forged body' and 'forged bottom plate' which are independently forged. JSW has developed the manufacturing technology of 'cask body integrated with bottom plate' which has no weld line with the goal of cost reduction, manufacturing period shortening and further reliability improvement. Manufacturing for the prototype of 'cask body integrated with bottom plate' has completed to verify mechanical properties and uniformity of the product which satisfy the specified values stipulated in JSME Code S FA1 2007 edition. Here, we report the manufacturing technology and obtained properties of 'cask body integrated with bottom plate'. (author)

A apropriação de imagens de arquivo na obra de Harun Farocki e Péter Forgács

Directory of Open Access Journals (Sweden)

Jamer Guterres de Mello

2012-12-01

Full Text Available This paper aims to discuss the use of archival and found footage as aprocedure whose objective is to stand out aesthetical and discursive singularities thatmisplace images original senses and create new senses for them. For this purpose, someaspects of the filmography of Harun Farocki and Péter Forgács will be analyzed. These twoartists have been adopting this gesture of appropriation, causing the re-signification of theoriginal meanings of the images.Keywords:

Manufacture of piping components for nuclear power plants

International Nuclear Information System (INIS)

Bartecek, R.

1983-01-01

Hammer forging of hollow forging ingots, extrusion and elestroslag remelting may be used for the manufacture of large pipes. Technologies have been developed for the manufacture of elbows based on various types of forming. These procedures mainly include the hydraulic pressing of elbows from tubes and the pressing of symmetrical halves of elbows with subsequent welding. The hammer forging of valves, cross pieces, etc., has been replaced by forging and pressing. In order to prevent failures from occurring in the pipes during operation of nuclear power plants, pipes are being made of larger forgings, which reduces the number of welds. This improves the quality of the pipes, reduces production and assembly costs and is metal-saving. (E.S.)

MATERIAL CHOICE AND BLANKS OPERATION TECHNOLOGY OF AK6 ALUMINIUM ALLOY

Directory of Open Access Journals (Sweden)

N. YE. Kalinina

2014-03-01

Full Text Available Purpose. Justification of the material and heat treatment method of aluminum alloy for the manufacturing of parts, type «plate» based on the results of microstructure and mechanical properties research; development of technological process of blanks operation of AK6 aluminum alloy. Methodology. Powdered alloy based on aluminum type AK6 was the research material. Finished forgings with the size 2520×1520×65 mm were obtained as a result of the preparation and forging of the blanks. After mechanical treatment of the blanks they were exposed to thermal processing and milling. Structure of the metal was examined under light microscope MIM-8M. Brinell hardness was used as the strength alloy characteristic. Findings. Influence analysis of alloy elements on the structure of deformable aluminum alloys was carried out. Research of influence of heat treatment modes on structure and properties of the AK6 alloy were performed. The improved technological process, which made it possible to obtain the item with the improved structure and properties and lower costs is offered. Originality. The samples of AK6 powdered alloy on fire resistance were tested. It is established that under heating of an example in the oxidative flame, it does not ignite to a temperature of 705 °C. The cause of high fire resistance of AK6 alloy samples was found, it is connected with the presence in the material the evenly distributed, small oxide inclusions and amorphous oxide film on the surface. Practical value. Hard conditions of work (corrosion in marine and industrial atmosphere, static and shock loads, cyclic temperature allow the use of the item in various designs.

Harnessing Technology to Improve Formative Assessment of Student Conceptions in STEM: Forging a National Network

Science.gov (United States)

Haudek, Kevin C.; Kaplan, Jennifer J.; Knight, Jennifer; Long, Tammy; Merrill, John; Munn, Alan; Nehm, Ross; Smith, Michelle; Urban-Lurain, Mark

2011-01-01

Concept inventories, consisting of multiple-choice questions designed around common student misconceptions, are designed to reveal student thinking. However, students often have complex, heterogeneous ideas about scientific concepts. Constructed-response assessments, in which students must create their own answer, may better reveal students’ thinking, but are time- and resource-intensive to evaluate. This report describes the initial meeting of a National Science Foundation–funded cross-institutional collaboration of interdisciplinary science, technology, engineering, and mathematics (STEM) education researchers interested in exploring the use of automated text analysis to evaluate constructed-response assessments. Participants at the meeting shared existing work on lexical analysis and concept inventories, participated in technology demonstrations and workshops, and discussed research goals. We are seeking interested collaborators to join our research community. PMID:21633063

Lubricant influence on the ejection and roughness of in-die electro sinter forged Ti-discs

DEFF Research Database (Denmark)

Cannella, Emanuele; Nielsen, Chris Valentin

2018-01-01

Electro Sinter Forging (ESF) is a new sintering process based on Joule heating by high electrical current flowing through compacted metal powder under mechanical pressure. The whole process takes about three seconds and is based on a closed-die setup, where the sample is sintered inside a die....... A near-net shape component is therefore manufactured. One of the challenges associated with this process is the ejection of the sample after sintering. Due to powder compaction and axial loading during sintering, a radial pressure is generated at the die/sample interface. Consequently, the ejection can...... of commercially pure titanium powder. The force was measured while ejecting the samples by using a speed-controlled press. The surface roughness parameter Sa was measured by using a laser confocal microscope....

Geologic setting of the proposed West Flank Forge Site, California: Suitability for EGS research and development

Science.gov (United States)

Sabin, Andrew; Blake, Kelly; Lazaro, Mike; Blankenship, Douglas; Kennedy, Mack; McCullough, Jess; DeOreo, S.B.; Hickman, Stephen H.; Glen, Jonathan; Kaven, Joern; Williams, Colin F.; Phelps, Geoffrey; Faulds, James E.; Hinz, Nicholas H.; Calvin, Wendy M.; Siler, Drew; Robertson-Tait, Ann

2017-01-01

The proposed West Flank FORGE site is within the China Lake Naval Air Weapons Station (NAWS), China Lake, CA. The West Flank is west of the Coso geothermal field, an area of China Lake NAWS dominated by the Quaternary Coso volcanic field largely comprised of rhyolite domes and their volcaniclastic and epiclastic horizons. The largest dome flow complex, Sugarloaf Mountain, marks the northwestern margin of the geothermal field. The West Flank is situated due west of Sugarloaf. The geologic setting of the West Flank was determined from one deep well (83-11) drilled as a potential production hole in 2009. The bottom-hole temperature (BHT) of well 83-11 approaches 600 oF (315˚C), but flow tests demonstrate very low, non-commercial permeabilities. With the exception of the upper 600 feet of volcaniclastic alluvium, well 83-11 is completed in granitic basement. The West Flank possesses the primary attributes of a FORGE site: non-commercial permeability (geothermal fieldThe Coso Mountains host the Coso volcanic field and are within a right-releasing stepover between the dextral Airport Lake (ALF) and Little Lake fault zones (LLFZ) and the Wild Horse Mesa and Owens Valley faults. Two distinct fault populations have been identified at Coso: WNW-trending and antithetical, NE-trending strike-slip faults and N- to NNE-trending normal faults. These faults are both high permeability drilling targets at depth within the main (productive) geothermal field and they locally segment the field into distinct hydrothermal regimes. The West Flank may be segmented from the rest of the field by one such northerly trending fault. The overall minimum principal stress orientation in the main geothermal field varies from 103˚ to 108˚; however, the minimum horizontal principal stress in 83-11 is rotated to 081˚.

Influence of the coating process on the tribological conditions during cold forging with a MoS2 based lubricant

Science.gov (United States)

Lorenz, Robby; Hagenah, Hinnerk; Merklein, Marion

2018-05-01

Cold forging processes such as forward rod extrusion can be used to produce high quality components like connection rods, shafts and gears. The main advantages of these extruded components are sufficient surface quality, work hardening, compressive residual stresses and fatigue strength. Since one technical disadvantage of extruded components lies in the achievable tolerance classes, the improvement of these should be of crucial importance. For instance, the attainable workpiece accuracy and component quality can be influenced by adapting the tribological system in such a way that the resulting friction is specifically controlled in order to improve component forming. Lubricant modification is one practical way of adapting the tribological system to the requirements of the forming process. An industrial established and highly efficient lubricant system is the application of a zinc-phosphate conversion layer with a molybdenum disulfide-based lubricant. While offering many advantages, its tribological conditions seem to depend strongly on the layer weight and the application strategy. These parameters and the respective interdependencies have not been sufficiently investigated yet. In order to examine this, the tribological conditions depending on the layer weight are analyzed in greater detail using the Ring-Compression-Test (RCT). This tribometer provides a comparative representation of the forming conditions during cold forging. Furthermore, a potential dependency between the tribological conditions and two different coating techniques is analyzed. The latter are represented by the industrial standards dipping and dip-drumming.

Analysis of anisotropic damage in forged Al–Cu–Mg–Si alloy based on creep tests, micrographs of fractured specimen and digital image correlations

Energy Technology Data Exchange (ETDEWEB)

Gariboldi, Elisabetta, E-mail: elisabetta.gariboldi@polimi.it [Politecnico di Milano, Department of Mechanical Engineering, Via La Masa 34 20156 Milano (Italy); Naumenko, Konstantin, E-mail: konstantin.naumenko@ovgu.de [Otto-von-Guericke-University Magdeburg, Institute of Mechanics, D-39106 Magdeburg (Germany); Ozhoga-Maslovskaja, Oksana, E-mail: oksana.ozhogamaslovskaja@gmail.com [Politecnico di Milano, Department of Mechanical Engineering, Via La Masa 34 20156 Milano (Italy); Zappa, Emanuele, E-mail: emanuele.zappa@polimi.it [Politecnico di Milano, Department of Mechanical Engineering, Via La Masa 34 20156 Milano (Italy)

2016-01-15

The aim of this paper is to analyze anisotropic damage mechanisms in forged Al–Cu–Mg–Si alloy based on the results of creep tests. Smooth specimens are sampled in three forging directions. Creep strain vs. time curves as well as light optical microscope and scanning electron microscope observations illustrate basic features of damage growth. Flat notch specimens are sampled in different directions to analyze stress redistributions and damage in zones of stress concentration. The digital image correlation technique has been applied in situ in order to extract the strain values on the surface of the notched specimens. All observations demonstrate that the principal origins of anisotropic creep and damage are associated with elongated grains and second phase clustered particles located at grain boundaries. Longitudinal specimens possess nucleations of decohesion sites and growth of voids around second phase particles at grain boundaries. Damage evolution for radial and transverse specimens is due to the formation and growth of cracks in second phase particles orthogonal to the principal stress axis. Residual strains are confined to the notch root as well as to the flanges of advanced macrocrack, indicating the small scale yielding during the creep fracture process.

Properties of Ni-Mo steel prepared from premixed and prealloyed powder in sintered, forged and annealed state

International Nuclear Information System (INIS)

Salak, A.; Hrubjak, M.

Investigated were 2Ni-0.5Mo steel specimens made of premixed powder on the base of Hametag iron and of ATST-A prealloyed powder with graphite additives of 0.3% and 0.8%. In the sintered and forged state, specimens prepared from premixed powder exhibit better strength properties compared with those made of prealloyed ATST-A powder. After annealing, the carbon content has a different bearing on both systems. With premixed powder steel of 0.6% carbon content the tensile strength amounts to 1,800 MPa whilst that of prealloyed steel specimens with 0.2% carbon content is about 1,240 MPa. (author)

Simulation and experimental verification of the filling process of semi-solid die forging for cup shell

Directory of Open Access Journals (Sweden)

Jianbo TAN

2015-06-01

Full Text Available The filling mold process of semi-solid alloy blank influences severely the forming and properties of finished piece. In this paper, DEFORM is applied to simulate the process of cup-type 6061 alloy die forging casting. The influences of the temperature of semi-solid alloy blank, preheating temperature, and downward press speed of pressure head on process of mold filling and velocity field are investigated. The results show that the mold filling of semi-solid alloy paste smoothly fills along the whole of mould cavity in “total wall thickness” form when the temperature of semi-solid alloy blank is 620 ℃, preheating temperature of pressure head is 200 ℃ and speed of pressure head is 40 mm/s. Along with the increase of the preheating temperature of pressure head, the filling process of the semi-solid alloy paste trends toward stable when the temperature of semi-solid alloy blank is 620 ℃ and the speed of pressure head is 20 mm/s. Along with the increasing of the temperature of semi-solid alloy, the process of mould filling becomes off balance and the liquid becomes turbulent flow. The velocity field in the process of mould filling affects severely the structure uniformity of the finished product.

A study on die wear model of warm and hot forgings

Science.gov (United States)

Kang, J. H.; Park, I. W.; Jae, J. S.; Kang, S. S.

1998-05-01

Factors influencing service lives of tools in warm and hot forging processes are wear, mechanical fatigue, plastic deformation and thermal fatigue, etc. Wear is the predominant factor for tool failure among these. To predict tool life by wear, Archard's model where hardness is considered as constant or function of temperature is generally applied. Usually hardness of die is a function of not only temperature but operating time of die. To consider softening of die by repeated operation it is necessary to express hardness of die by a function of temperature and time. In this study wear coefficients were measured for various temperatures and heat treatment for H13 tool steel. Also by experiment of reheating of die, die softening curves were obtained. From experimental results, relationships between tempering parameters and hardness were established to investigate effects of hardness decrease by the effect of temperatures and time. Finally modified Archard's wear model in which hardness is considered to be a function of main tempering curve was proposed. And finite element analyses were conducted by adopting suggested wear model. By comparisons of simulations and real profiles of worn die, proposed wear model was verified.

Experimental study on combined cold forging process of backward cup extrusion and piercing

Science.gov (United States)

Henry, Robinson; Liewald, Mathias

2018-05-01

A reduction in material usage of cold forged components while maintaining the functional requirements can be achieved using hollow or tubular preforms. These preforms are used to meet lightweight requirements and to decrease production costs of cold formed components. To increase production efficiency in common multi-stage cold forming processes, manufacturing of hollow preforms by combining the processes backward cup extrusion and piercing was established and will be discussed in this paper. Corresponding investigations and experimental studies are reported in this article. The objectives of the experimental investigations have been the detection of significant process parameters, determination of process limits for the combined processes and validation of the numerical investigations. In addition, the general influence concerning surface quality and diameter tolerance of hollow performs are discussed in this paper. The final goal is to summarize a guideline for industrial application, moreover, to transfer the knowledge to industry, as regards what are required part geometries to reduce the number of forming stages as well as tool cost.

Structure and properties of large-sized forged disk of alloy type KhN73MBTYu-VD(EhI 698-VD)

International Nuclear Information System (INIS)

Sudakov, V.S.

1994-01-01

Investigation results are presented for structure and mechanical properties of serial large-sized forged disk 1100 mm in diameter produced of alloy type EhI 9698-VD hand tested after standard heat treatment and isothermal ageing at operating temperature. Chemical composition studies have revealed no macroheterogeneity. In a central cross-section macrostructure is free of pores, inclusions, delaminating and variation in grain size. The metal of the disk possesses high values of long-term rupture strength and creep resistance at 650-700 deg C

Minimization of Residual Stress in an Al-Cu Alloy Forged Plate by Different Heat Treatments

Science.gov (United States)

Dong, Ya-Bo; Shao, Wen-Zhu; Jiang, Jian-Tang; Zhang, Bao-You; Zhen, Liang

2015-06-01

In order to improve the balance of mechanical properties and residual stress, various quenching and aging treatments were applied to Al-Cu alloy forged plate. Residual stresses determined by the x-ray diffraction method and slitting method were compared. The surface residual stress measured by x-ray diffraction method was consistent with that measured by slitting method. The residual stress distribution of samples quenched in water with different temperatures (20, 60, 80, and 100 °C) was measured, and the results showed that the boiling water quenching results in a 91.4% reduction in residual stress magnitudes compared with cold water quenching (20 °C), but the tensile properties of samples quenched in boiling water were unacceptably low. Quenching in 80 °C water results in 75% reduction of residual stress, and the reduction of yield strength is 12.7%. The residual stress and yield strength level are considerable for the dimensional stability of aluminum alloy. Quenching samples into 30% polyalkylene glycol quenchants produced 52.2% reduction in the maximum compressive residual stress, and the reduction in yield strength is 19.7%. Moreover, the effects of uphill quenching and thermal-cold cycling on the residual stress were also investigated. Uphill quenching and thermal-cold cycling produced approximately 25-40% reduction in residual stress, while the effect on tensile properties is quite slight.

Evolution of ESR Technology and Equipment for Long Hollow Ingots Manufacture

Science.gov (United States)

Medovar, Lev; Stovpchenko, Ganna; Dudka, Grigory; Kozminskiy, Alexander; Fedorovskii, Borys; Lebid, Vitalii; Gusiev, Iaroslav

In this paper development of both ESR technology and equipment for hollow ingot manufacture review and analysis are presented. The real complications of hollow ingot manufacture and some tendentious issues which restrict process dissemination are discussed. An actual data of modern manufacture of as-cast pipes for heat and power engineering by traditional ESR with consumable electrode are given. Results of microstructure and nonmetal inclusion investigations have shown the high quality of as-cast ESR pipes. On the basis of these results the possibility to produce huge ESR hollows (up 5000 mm in dia) with final goal drastically to reduce setting ratio on forged shells and rings or even replace it by ESR hollows as-cast is grounded. Two new ESR technologies — consumable electrodes change and liquid metal usage — have passed pilot tests for heavy hollow production and shown very prospective results to be presented.

Heavy-Section Steel Technology program fracture issues

International Nuclear Information System (INIS)

Pennell, W.E.

1989-10-01

Large scale fracture mechanics tests have resulted in the identification of a number of fracture technology issues. Identification of additional issues has come from the reactor vessel materials irradiation test program and from reactor operating experience. This paper provides a review of fracture issues with an emphasis on their potential impact on a reactor vessel pressurized thermal shock (PTS) analysis. Mixed mode crack propagation emerges as a major issue, due in large measure to the poor performance of existing models for the prediction of ductile tearing. Rectification of ductile tearing technology deficiencies may require extending the technology to include a more complete treatment of stress state and loading history effects. The effect of cladding on vessel fracture remains uncertain to the point that it is not possible to determine at this time if the net effect will be positive or negative. Enhanced fracture toughness for shallow flaws has been demonstrated for low strength structural steels. Demonstration of a similar effect in reactor pressure vessel steels could have a significant beneficial effect on the probabilistic analysis of reactor vessel fracture. Further development of existing fracture mechanics models and concepts is required to meet the special requirements for fracture evaluation of circumferential flaws in the welds of ring forged vessels. Fracture technology advances required to address the issues discussed in this paper are the major objective for the ongoing Heavy Section Steel Technology (HSST) program at ORNL. 24 refs., 18 figs

Heavy-section steel technology program: Fracture issues

International Nuclear Information System (INIS)

Pennell, W.E.

1992-01-01

Large-scale fracture mechanics tests have resulted in the identification of a number of fracture technology issues. Identification of additional issues has come from the reactor vessel materials irradiation test program and from reactor operating experience. This paper provides a review of fracture issues with an emphasis on their potential impact on a reactor vessel pressurized thermal shock (PTS) analysis. Mixed mode crack propagation emerges as a major issue, due in large measure to the poor performance of existing models for the prediction of ductile tearing. Rectification of ductile tearing technology deficiencies may require extending the technology to include a more complete treatment of stress state and loading history effects. The effect of cladding on vessel fracture remains uncertain to the point that it is not possible to determine at this time if the net effect will be positive or negative. Enhanced fracture toughness for shallow flaws has been demonstrated for low-strength structural steels. Demonstration of a similar effect in reactor pressure vessel steels could have a significant beneficial effect on the probabilistic analysis of reactor vessel fracture. Further development of existing fracture mechanics models and concepts is required to meet the special requirements for fracture evaluation of circumferential flaws in the welds of ring-forged vessels. Fracture technology advances required to address the issues discussed in this paper are the major objective for the ongoing Heavy Section Steel Technology (HSST) program at ORNL

Multimedia and co-operative work in new product development : A participatory approach to virtual prototyping

NARCIS (Netherlands)

Muller, P; vanEngelen, J; Terlouw, P; deVreede, GJ

1996-01-01

In order to be successful, nov product development requires a balance between market pull and technology push. On a project level this involves forging a link between the (technical) capabilities of the company and the needs of the market place. This paper describes an approach to forge this link

Corrosion fatigue crack growth in clad low-alloy steels: Part 1, medium-sulfur forging steel

International Nuclear Information System (INIS)

James, L.A.; Poskie, T.J.; Auten, T.A.; Cullen, W.H.

1996-01-01

Corrosion fatigue crack propagation tests were conducted on a medium- sulfur ASTM A508-2 forging steel overlaid with weld-deposited Alloy EN82H cladding. The specimens featured semi-elliptical surface cracks penetrating approximately 6.3 mm of cladding into the underlying steel. The initial crack sizes were relatively large with surface lengths of 30.3--38.3 mm, and depths of 13.1--16.8 mm. The experiments were conducted in a quasi-stagnant low-oxygen (O 2 < 10 ppb) aqueous environment at 243 degrees C, under loading conditions (ΔK, R, and cyclic frequency) conductive to environmentally-assisted cracking (EAC) in higher-sulfur steels under quasi-stagnant conditions. Earlier experiments on unclad compact tension specimens of this heat of steel did not exhibit EAC, and the present experiments on semi-elliptical surface cracks penetrating cladding also did not exhibit EAC

Forged steel pistons for modern high performance large engines; used in 4 stroke diesel and heavy fuel oil engines with cylinder bores of 130 - 500 mm; Geschmiedete Stahlkolben fuer moderne Hochleistungs-Grossmotoren, eingesetzt in 4 Takt Diesel- und Schweroelmotoren mit Zylinderdurchmessern von 130 - 500 mm

Energy Technology Data Exchange (ETDEWEB)

Kortas, J.; Geissler, C.; Schmidt, R. [Mahle GmbH, Stuttgart (Germany)

2004-07-01

The permanent increase of engine load caused MAHLE to develop pistons made of forged steel. On one hand, the result of the development is a Monotherm registered -piston design mainly used in truck applications. On the other hand, the result is a Ferrocomp registered - piston design with its application in large bore engines. The Ferrocomp registered - piston consists of a forged steel skirt and a forged crown which are bolted together. The main requirements of maximum load bearing capacity and highest reliability are achieved with these steel piston concepts. Many calculations and simulations together with laboratory testing and some thousands of field test experience give us the confidence for production release. A maximum peak cylinder pressure of 25 MPa and more is obtainable. For engines with less demanding load capacity and a stringent weight limitation the aluminium piston and the composite piston with an aluminum skirt are still the right solutions. (orig.)

The use of electromagnetic field in designing the high quality Al alloys for hot forging process

Directory of Open Access Journals (Sweden)

Zvonko Gulišija

2014-12-01

Full Text Available This work presents a way to obtain the better quality of EN AW 7075 aluminum high-strength alloy by application of electromagnetic field (EMF during the casting process. In this way, the uniform fine-grained microstructure, and hence the better mechanical properties of the alloy can be achieved. The microstructure and mechanical characterization for samples obtained with and without EMF were performed. The application of numerical simulation for hot forging process, using appropriate software, is efficient and highly useful tool for problem prediction in industrial production, reducing the time and costs in the process of development of new products. The input data of high strength Al-alloy EN AW-7075 is used for simulation because it enables the development of parts with complex dimensions and shape.

Excellent superplasticity and deformation mechanism of Al–Mg–Sc–Zr alloy processed via simple free forging

Energy Technology Data Exchange (ETDEWEB)

Duan, Y.L. [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Xu, G.F., E-mail: csuxgf660302@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083, China. (China); Xiao, D.; Zhou, L.Q. [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Deng, Y.; Yin, Z.M. [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083, China. (China)

2015-01-29

A refined microstructure of Al–Mg–Sc–Zr alloy with an average grain size of ∼3.7 μm and a portion of high angle boundaries of 69.2% was produced by free forging. Excellent superplastic ductility of ≥500% was achieved at a wide temperature range of 450∼500 °C and relatively high strain rate range of 1×10{sup −3}∼5×10{sup −2} s{sup −1} in the Al–Mg–Sc–Zr alloy. A maximum elongation of 1593% was obtained at 475 °C and 1×10{sup −3} s{sup −1}. Moreover, the electron back scattered diffraction (EBSD) and the transmission electron microscopy (TEM) analyses showed that the excellent superplasticity can be attributed to the high fraction of high angle grain boundaries and the presence of Al{sub 3}(Sc,Zr) dispersoids in the Al–Mg–Sc–Zr alloy microstructure. The analyses on the superplastic data revealed the presence of threshold stress, the coefficient of strain rate sensitivity of 0.5, and an activation energy of 83.9 kJ/mol{sup –1}. It indicated that the dominant deformation mechanism was grain boundary sliding. Based on this notion, a constitutive equation for Al–Mg–Sc–Zr alloy has been developed.

Design and Optimization of Die Preforming Process for Long Last-stage Blade of Nuclear Power

Directory of Open Access Journals (Sweden)

He Xiaomao

2017-01-01

Full Text Available The long last-stage blade is a key component of the steam turbine of nuclear conventional island. The die preforming process for a new technology that provides billets for near-net-shape roll-forging process was designed, the effects of the forging temperature, friction coefficient, flash land’s height and die’s outer fillet radius on the die forging force and forging energy were studied by using the orthogonal experiment method, the primary and secondary order of the four factors were analysed by using range analysis method, and the optimal combination of the factors was obtained. By means of numerical simulation and physical experiment, the die preforming process that can provide qualified billets for the subsequent roll-forging process was verified, and the PZS1120f electric screw press can meet the requirements of the die preforming process.

Towards fraud-proof ID documents using multiple data hiding technologies and biometrics

Science.gov (United States)

Picard, Justin; Vielhauer, Claus; Thorwirth, Niels

2004-06-01

Identity documents, such as ID cards, passports, and driver's licenses, contain textual information, a portrait of the legitimate holder, and eventually some other biometric characteristics such as a fingerprint or handwritten signature. As prices for digital imaging technologies fall, making them more widely available, we have seen an exponential increase in the ease and the number of counterfeiters that can effectively forge documents. Today, with only limited knowledge of technology and a small amount of money, a counterfeiter can effortlessly replace a photo or modify identity information on a legitimate document to the extent that it is very diffcult to differentiate from the original. This paper proposes a virtually fraud-proof ID document based on a combination of three different data hiding technologies: digital watermarking, 2-D bar codes, and Copy Detection Pattern, plus additional biometric protection. As will be shown, that combination of data hiding technologies protects the document against any forgery, in principle without any requirement for other security features. To prevent a genuine document to be used by an illegitimate user,biometric information is also covertly stored in the ID document, to be used for identification at the detector.

Liquid helium boil-off measurements of heat leakage from sinter-forged BSCCO current leads under DC and AC conditions

International Nuclear Information System (INIS)

Cha, Y.S.; Niemann, R.C.; Hull, J.R.; Youngdahl, C.A.; Lanagan, M.T.; Nakade, M.; Hara, T.

1995-06-01

Liquid helium boil-off experiments are conducted to determine the heat leakage rate of a pair of BSCCO 2223 high-temperature superconductor current leads made by sinter forging. The experiments are carried out in both DC and AC conditions and with and without an intermediate heat intercept. Current ranges are from 0-500 A for DC tests and 0-1,000 A rms for AC tests. The leads are self-cooled. Results show that magnetic hysteresis (AC) losses for both the BSCCO leads and the low-temperature superconductor current jumper are small for the current range. It is shown that significant reduction in heat leakage rate (liquid helium boil-off rate) is realized by using the BSCCO superconductor leads. At 100 A, the heat leakage rate of the BSCCO/copper binary lead is approximately 29% of that of the conventional copper lead. Further reduction in liquid helium boil-off rate can be achieved by using an intermediate heat intercept. For example, at 500 K, the heat leakage rate of the BSCCO/copper binary lead is only 7% of that of the conventional copper lead when an intermediate heat intercept is used

Microstructural evolutions in warm compression of Betacez and 6246 titanium alloys and influence of the forging on the transformation {beta} {yields} {alpha}; Evolutions microstructurales en compression a chaud des alliages de titane Betacez et 6246 et influence du forgeage sur la transformation {beta} {yields} {alpha}

Energy Technology Data Exchange (ETDEWEB)

Chaussy Mraizika, F

1996-06-26

The relations between the thermomechanical ranges and the microstructures of titanium alloys are still insufficient. This work proposes to improve the knowledge of structural state coming from the {beta} forging and the ulterior transformation {beta} to {alpha}+{beta}. The influence of the two parameters, rate and strain speed, on the microstructural and textural evolutions appear during the forging and also during the {beta}/{alpha} transformation are systematically studied. The two titanium alloys which are studied are Betacez titanium alloy and the 6246 titanium alloy. (N.C.)

The implementation of microstructural and heat treatment models to development of forming technology of critical aluminum-alloy parts

Science.gov (United States)

Biba, Nikolay; Alimov, Artem; Shitikov, Andrey; Stebunov, Sergei

2018-05-01

The demand for high performance and energy efficient transportation systems have boosted interest in lightweight design solutions. To achieve maximum weight reductions, it is not enough just to replace steel parts by their aluminium analogues, but it is necessary to change the entire concept of vehicle design. In this case we must develop methods for manufacturing a variety of critical parts with unusual and difficult to produce shapes. The mechanical properties of the material in these parts must also be optimised and tightly controlled to provide the best distribution within the part volume. The only way to achieve these goals is to implement technology development methods based on simulation of the entire manufacturing chain from preparing a billet through the forming operations and heat treatment of the product. The paper presents an approach to such technology development. The simulation of the technological chain starts with extruding a round billet. Depending on the extrusion process parameters, the billet can have different levels of material workout and variation of grain size throughout the volume. After extrusion, the billet gets formed into the required shape in a forging process. The main requirements at this stage are to get the near net shape of the product without defects and to provide proper configuration of grain flow that strengthens the product in the most critical direction. Then the product undergoes solution treatment, quenching and ageing. The simulation of all these stages are performed by QForm FEM code that provides thermo-mechanical coupled deformation of the material during extrusion and forging. To provide microstructure and heat treatment simulation, special subroutines has been developed by the authors. The proposed approach is illustrated by an industrial case study.

Laser rapid forming technology of high-performance dense metal components with complex structure

Science.gov (United States)

Huang, Weidong; Chen, Jing; Li, Yanming; Lin, Xin

2005-01-01

Laser rapid forming (LRF) is a new and advanced manufacturing technology that has been developed on the basis of combining high power laser cladding technology with rapid prototyping (RP) to realize net shape forming of high performance dense metal components without dies. Recently we have developed a set of LRF equipment. LRF experiments were carried out on the equipment to investigate the influences of processing parameters on forming characterizations systematically with the cladding powder materials as titanium alloys, superalloys, stainless steel, and copper alloys. The microstructure of laser formed components is made up of columnar grains or columnar dendrites which grow epitaxially from the substrate since the solid components were prepared layer by layer additionally. The result of mechanical testing proved that the mechanical properties of laser formed samples are similar to or even over that of forging and much better than that of casting. It is shown in this paper that LRF technology is providing a new solution for some difficult processing problems in the high tech field of aviation, spaceflight and automobile industries.

The effects of microstructure on the temper embrittlement susceptibility of a 2 1/4Cr1Mo forging

International Nuclear Information System (INIS)

Gage, G.; Edwards, B.C.; Hudson, J.A.

This paper describes the results of a detailed metallurgical assessment of the microstructural stability and temper embrittlement susceptibility of a 255mm thick 2 1/4Cr1Mo steel forging which was manufactured by a process typical of that used for the tube plates of steam generator units. Ageing effects were studied over the temperature range 450-575 deg. C for times up to 20,000h. Grain boundary compositional changes were monitored using Auger Electron Spectroscopy (AES) and microstructural changes determined by both transmission electron microscopy and X-ray analysis. Brittle intergranular failure was produced in the lower shelf energy regime and AES analysis showed that this was associated with the grain boundary segregation of phosphorus. This segregation was shown to exhibit equilibrium characteristics and was consistent with that of phosphorus segregation in α-iron. Implying no significant alloy-impurity interaction. The shift in the ductile-to-brittle transition temperature was not uniquely a function of the grain boundary segregation but was shown to be dependent upon both the level of grain boundary solute segregation and the type of precipitate particles present. Heat treatment conditions which promoted the formation of M 6 C precipitates were particularly deleterious to toughness. (author)

Development of a novel cold forging process to manufacture eccentric shafts

Science.gov (United States)

Pasler, Lukas; Liewald, Mathias

2018-05-01

Since the commercial usage of compact combustion engines, eccentric shafts have been used to transform translational into rotational motion. Over the years, several processes to manufacture these eccentric shafts or crankshafts have been developed. Especially for single-cylinder engines manufactured in small quantities, built crankshafts disclose advantages regarding tooling costs and performance. Those manufacturing processes do have one thing in common: They are all executed at elevated temperatures to enable the material to be formed to high forming degree. In this paper, a newly developed cold forging process is presented, which combines lateral extrusion and shifting for manufacturing a crank in one forming operation at room temperature. In comparison to the established upsetting and shifting methods to manufacture such components, the tool cavity or crank web thickness remains constant. Therefore, the developed new process presented in this paper consists of a combination of shifting and extrusion of the billet, which allows pushing material into the forming zone during shifting. In order to reduce the tensile stresses induced by the shifting process, compressive stresses are superimposed. It is expected that the process limits will be expanded regarding the horizontal displacement and form filling. In the following report, the simulation and design of the tooling concept are presented. Experiments were conducted and compared with corresponding simulation results afterwards.

Micropurity in stainless steel making

International Nuclear Information System (INIS)

Motloch, Z.

1981-01-01

New technologies were developed by the Vitkovice research institutes in response to high requirements for the quality of high-alloy steels for nuclear power, viz., duplex technology with double vacuum degassing at the DH unit and oxidation vacuum degassing using the VAKUVIT equipment. The steel produced shows low contents of impurities and high micropurity. A study was conducted into changes in carbon content and the formation of titanium nitrides and carbonitrides in austenitic steels during their production, and optimum technological parameters were found for eliminating their formation in forgings. (author)

Analysis and Nanomold Design for Aluminum Nanoimprinting

Directory of Open Access Journals (Sweden)

Te-Hua Fang

2014-11-01

Full Text Available The nanoforging process and mechanism of pure aluminum samples is studied using molecular dynamics (MD simulations based on embedded atom method (EAM potential function. The effects of the forging temperature and the forging velocity are evaluated in terms of molecular trajectories, internal energy, and a radial distribution function. The simulation results clearly show that the internal energy of the workpiece exerted on it during the forging process have high energy with decreasing forging temperature ; however, with increasing forging velocity, the internal energy have higher energy. During the forging process, a special atomic structure in (011 and (0 slip planes was observed, and that represents the site of generation of dislocation and growth nucleation. When severe plastic deformation occurs, the density of the workpiece varied. The forged workpiece has similar distributions of atomic density after the loading for various forging temperatures and forging velocities.

Microstructure-based assessment of creep rupture behaviour of cast-forged P91 steel

Energy Technology Data Exchange (ETDEWEB)

Pandey, Chandan, E-mail: chandanpy.1989@gmail.com [Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Uttrakhand 247667 (India); Mahapatra, M.M. [School of Mechanical Sciences, Indian Institute of Technology Bhubaneswar, Odisha 751013 (India); Kumar, Pradeep; Vidyrathy, R.S. [Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Uttrakhand 247667 (India); Srivastava, A. [Senior Engineer, HEEP Section, BHEL Haridwar (India)

2017-05-17

The work presented in this study was performed with the intent to characterize the microstructure evolution for short term creep exposure of cast-forged P91 steel. The short-term creep test was performed at temperature range of 620–650 °C and stresses ranging from 120 to 200 MPa. To characterize the sample after creep exposure, field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDS), optical microscope and micro-hardness testing were utilized. Creep tests were performed on round creep specimens. For low temperature service condition, longer creep life was obtained. The fracture surface of creep ruptured specimen were characterized by using the FESEM. The transgranular fracture mode was noticed in all the tests condition. The creep rupture life was found to be decreased with increase in applied stress. The maximum rupture life was measured about to be 3329.28 h for the sample exposed at 620 °C for 120 MPa. A negligible microstructural change was measured in gripping area compared to the gauge area (necking area) of crept sample. The laves phase formation was also noticed along the grain boundaries for creep exposure life of 3329.28 h.

Microstructure-based assessment of creep rupture behaviour of cast-forged P91 steel

International Nuclear Information System (INIS)

Pandey, Chandan; Mahapatra, M.M.; Kumar, Pradeep; Vidyrathy, R.S.; Srivastava, A.

2017-01-01

The work presented in this study was performed with the intent to characterize the microstructure evolution for short term creep exposure of cast-forged P91 steel. The short-term creep test was performed at temperature range of 620–650 °C and stresses ranging from 120 to 200 MPa. To characterize the sample after creep exposure, field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDS), optical microscope and micro-hardness testing were utilized. Creep tests were performed on round creep specimens. For low temperature service condition, longer creep life was obtained. The fracture surface of creep ruptured specimen were characterized by using the FESEM. The transgranular fracture mode was noticed in all the tests condition. The creep rupture life was found to be decreased with increase in applied stress. The maximum rupture life was measured about to be 3329.28 h for the sample exposed at 620 °C for 120 MPa. A negligible microstructural change was measured in gripping area compared to the gauge area (necking area) of crept sample. The laves phase formation was also noticed along the grain boundaries for creep exposure life of 3329.28 h.

Comparative tensile flow and work hardening behaviour of thin section and forged thick section 9Cr–1Mo ferritic steel in the framework of Voce equation and Kocks–Mecking approach

International Nuclear Information System (INIS)

Choudhary, B.K.; Rao Palaparti, D.P.

2012-01-01

Detailed analysis indicated that true stress (σ)-true plastic strain (ε) and work hardening behaviour of 9Cr–1Mo steel in two different forms, i.e. 20 mm plate and thick section tubeplate forging can be adequately described by Voce equation and Kocks–Mecking approach in the temperature range 300–873 K. The steel exhibited two-stage work hardening in the variations of instantaneous work hardening rate (θ = dσ/dε) and θσ with stress. The variations in σ–ε, work hardening parameters, θ–σ and θσ–σ with temperature exhibited three distinct temperature regimes. Good correlations between the predicted tensile properties using Voce equation and the respective experimental values along with analogy between Voce equation and Kocks–Mecking approach have been demonstrated for the steel. The differences in σ–ε, work hardening parameters, θ–σ and θσ–σ observed between plate and tubeplate forging have been ascribed to the effects associated with initial microstructures for the two product forms of the steel.

Fiscal 1992 survey report of R and D on new forming technology of composite material. Development of innovative technology for producing members for high efficiency power generation; 1992 nendo fukugo zairyo seikei gijutsu chosa hokokusho. Fukugo zairyo shinseikei gijutsu no kenkyu kaihatsu (kokoritsu hatsuden'yo buzai soseigijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-03-01

Composite forming technology is being developed which is intended to manifest superplasticity phenomenon of ceramic matrix and metallic matrix composite materials; also being developed is an effective efficient superplastic processing technology which utilizes this composite forming technology. The related technologies were investigated comprehensively systematically with the purpose of promoting the development. First, an overview was given in the present state and problems of ceramic matrix/metallic matrix composite technologies and in the forefront of the superplasticity research of ceramic matrix materials, and then, the related technologies of these composite materials were pigeonholed under the following items: 1. assesment/strength/dynamic properties, 2. composite process and property, 3. composite forming process, 4. superplasticity, 5. process and superplasticity, and 6. others. The titles of the rearranged summary documents are, for example, surface modification and casting of SiC platelets in Al{sub 2}O{sub 3} composites, deformation of Al{sub 2}O{sub 3}/TiC composites at elevated temperatures, superplastic bulging of fine-grained zirconia, forging of short alumina fiber reinforced aluminum alloy, and on superplasticity in silicon carbide reinforced aluminum composites. (NEDO)

Fiscal 1992 survey report of R and D on new forming technology of composite material. Development of innovative technology for producing members for high efficiency power generation; 1992 nendo fukugo zairyo seikei gijutsu chosa hokokusho. Fukugo zairyo shinseikei gijutsu no kenkyu kaihatsu (kokoritsu hatsuden'yo buzai soseigijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-03-01

Composite forming technology is being developed which is intended to manifest superplasticity phenomenon of ceramic matrix and metallic matrix composite materials; also being developed is an effective efficient superplastic processing technology which utilizes this composite forming technology. The related technologies were investigated comprehensively systematically with the purpose of promoting the development. First, an overview was given in the present state and problems of ceramic matrix/metallic matrix composite technologies and in the forefront of the superplasticity research of ceramic matrix materials, and then, the related technologies of these composite materials were pigeonholed under the following items: 1. assesment/strength/dynamic properties, 2. composite process and property, 3. composite forming process, 4. superplasticity, 5. process and superplasticity, and 6. others. The titles of the rearranged summary documents are, for example, surface modification and casting of SiC platelets in Al{sub 2}O{sub 3} composites, deformation of Al{sub 2}O{sub 3}/TiC composites at elevated temperatures, superplastic bulging of fine-grained zirconia, forging of short alumina fiber reinforced aluminum alloy, and on superplasticity in silicon carbide reinforced aluminum composites. (NEDO)

Disintegration of the net-shaped grain-boundary phase by multi-directional forging and its influence on the microstructure and properties of Cu-Ni-Si alloy

Science.gov (United States)

Zhang, Jinlong; Lu, Zhenlin; Zhao, Yuntao; Jia, Lei; Xie, Hui; Tao, Shiping

2017-09-01

Cu-Ni-Si alloys with 90% Cu content and Ni to Si ratios of 5:1 were fabricated by fusion casting, and severe plastic deformation of the Cu-Ni-Si alloy was carried out by multi-direction forging (MDF). The results showed that the as-cast and homogenized Cu-Ni-Si alloys consisted of three phases, namely the matrix phase α-Cu (Ni, Si), the reticular grain boundary phase Ni31Si12 and the precipitated phase Ni2Si. MDF significantly destroyed the net-shaped grain boundary phase, the Ni31Si12 phase and refined the grain size of the Cu matrix, and also resulted in the dissolving of Ni2Si precipitates into the Cu matrix. The effect of MDF on the conductivity of the solid solution Cu-Ni-Si alloy was very significant, with an average increase of 165.16%, and the hardness of the Cu-Ni-Si alloy also increased obviously.

Cold forging stem of total hip prosthesis with hybrid mechanical properties; Forjamento a frio de hastes de protese total de quadril com propriedades mecanicas hibridas

Energy Technology Data Exchange (ETDEWEB)

Lopes, E.S.N.; Contieri, R.J.; Cardoso, F.F.; Cremasco, A.; Button, S.T.; Caram, R., E-mail: ederlopes@fem.unicamp.b [Universidade Estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Materiais

2010-07-01

Type {beta} Ti alloy is one of the most versatile groups of materials with regard to mechanical properties. Aspects such as alloying elements selection, mechanical processing and heat treatment routes empower these materials in applications where hybrid mechanical behavior is necessary. The aim of this study is to produce stems of total hip prostheses with hybrid mechanical properties using Ti-Nb alloys. Ingots were produced by using arc melting. Following, samples were subjected to specific heat treatment aiming to make cold forging. Sample characterization includes X-ray diffraction, scanning electron microscopy, Vickers hardness tests and tensile test. The experiments performed allowed to examine the effects of heat treatment parameters on the microstructure and mechanical behavior. Finally, results obtained show that the application of specific heat treatments of quenching and aging makes feasible the manufacturing of orthopedic devices with hybrid mechanical properties with regions where high mechanical strength was prioritized, while in others, low elastic modulus was the main concern. (author)

Fiscal 1993 report on technological results. R and D on new forming technology of composite materials (Development of innovative technology for producing members for high efficiency power generation); 1993 nendo fukugo zairyo shinseikei gijutsu no kenkyu kaihatsu seika hokokusho. Kokoritsu hatsuden'yo buzai sosei gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

A forming technology was developed which uses superplasticity of composite materials, i.e., high-functional materials for power generating equipment for example. Activities were conducted in the three areas of (1) ceramic based composite materials, (2) development of metal-based composite forming technology, and (3) comprehensive investigation and adjustment. In (1), with a view to finding a composite forming technology, in which high tenacity materials are obtained by evenly dispersing particles or whiskers as reinforcements in a matrix, a room temperature forming technique using fine particles was exploited, as were a high temperature forming technique using fused bodies and a possibility of manifestation of superplasticity in the prepared composite materials. The materials used were Si{sub 3}N{sub 4} matrix-SiC, Al{sub 2}O{sub 3} matrix-TiC, and glass matrix composite based materials filling ceramics in fine holes of porous glass. In (2), composite forming technologies were examined for such composite materials as Al alloy matrix-SiC particulate-based by a molten metal stirring method, Al alloy matrix-ceramics short fiber-based by a high pressure forging method, Ti alloy matrix-ceramics particulate-based by a mechanical alloying method, and Al alloy matrix-ceramics particulate-based by an alkoxide method/powder metallurgy method. (NEDO)

Fiscal 1999 report on results of R and D of industrial science and technology that creates new industry. Development of super metal technology (development of technology for innovative metallic material); 1999 nendo super metal no gijutsu kaihatsu seika hokokusho. Kakushinteki kinzoku sokei zairyo no gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

With the purpose of obtaining higher strength/toughness and higher anticorrosion in metallic materials, R and D was conducted on technologies for grain refining/dispersing and for amorphous bulk formed bodies, with fiscal 1999 results compiled. In the technological study on grain refinement and dispersion, austenitic stainless steel and 12Cr ferrite steel were used, with creative manufacturing carried out for microcrystallized structure materials by a powder metallurgy method. The result of the study revealed that suppressing grain growth by carbide or oxide was important for grain refinement, and that homogenizing the inside of a material by hot forging after solidification forming was essential for ductility improvement. In the development of the technology for amorphous bulk formed bodies, a laser heating type forming test device was designed and manufactured, with a technique examined in which bulk amorphous of a complex-shaped article was formed through rapid quenching of amorphous alloy powder by laser. This year, a trial production was performed for the laminated solidified bodies of Ni amorphous alloy powder, and the basic data was thereby collected such as feeding of the powder and conditions of the laser irradiation. (NEDO)

Influence of Solution Treatment Temperature on Microstructural Properties of an Industrially Forged UNS S32750/1.4410/F53 Super Duplex Stainless Steel (SDSS Alloy

Directory of Open Access Journals (Sweden)

Vasile Dănuț Cojocaru

2017-06-01

Full Text Available In this present study, the influence of solution annealing temperature on microstructural properties of a forged Super Duplex Stainless Steel (SDSS was investigated by SEM-BSE (Scanning Electron Microscopy-Backscattered Electrons and SEM-EBSD (Scanning Electron Microscopy-Electron Backscatter Diffraction techniques. A brief solution treatment was applied to the forged super duplex alloy, at different temperatures between 800 °C and 1100 °C, with a constant holding time of 0.6 ks (10 min. Microstructural characteristics such as nature, weight fraction, distribution and morphology of constituent phases, average grain-size and grain misorientation were analysed in relation to the solution annealing temperature. Experimental results have shown that the constituent phases in the SDSS alloy are δ-Fe, γ-Fe and σ (Cr-Fe and that their properties are influenced by the solution treatment temperature. SEM examinations revealed microstructural modifications induced by the Cr rich precipitates along the δ/γ and δ/δ grain boundaries, which may significantly affect the toughness and the corrosion resistance of the alloy. Solution annealing at 1100 °C led to complete dissolution of σ (Cr-Fe phase, the microstructure being formed of primary δ-Fe and γ-Fe. The orientation relationship between δ/δ, γ/γ and δ/γ grains was determined by electron back scattering diffraction (EBSD. Both primary constituent phase’s microhardness and global microhardness were determined.

Progress in fusion technology at SWIP

Energy Technology Data Exchange (ETDEWEB)

Duan, X.R., E-mail: duanxr@swip.ac.cn; Chen, J.M.; Feng, K.M.; Liu, X.; Li, B.; Wu, J.H.; Wang, X.Y.; Zheng, P.F.; Wang, Y.Q.; Wang, P.H.; Liu, Yong

2016-11-01

Highlights: • Dispersion strengthened CLF-1 steel, vanadium alloys and tungsten alloys are developed. • The HCCB TBM conceptual design, development of functional materials such as Li{sub 4}SiO{sub 4} pebbles and Be pebbles are in progress. • A full size prototype shield block has been fabricated and passed ITER qualification. • Advanced divertor for a new tokamak are designed and analyzed. • GIS and GDC have entered the engineering design phase. - Abstract: The fusion research activities at Southwestern Institute of Physics (SWIP) include the HL-2A & HL-2M tokamak programs, fusion reactor design and materials, along with key fusion technologies including R&D on ITER procurement packages. This paper presents the progress of fusion technology at SWIP, including the ITER first wall and blanket, Chinese helium cooled ceramic breeder test blanket module (HCCB–TBM) for ITER, gas injection system and gas discharge cleaning system, as well as the recent activities on reactor materials and R&D related to advanced divertor. The final design for ITER first wall and blanket shielding blocks allocated to SWIP have been completed, and were validated by recent tests. Major manufacturing technologies, such as forging, deep drilling, explosion bonding and deep laser welding, have been successfully demonstrated. Furthermore, the conceptual design of CN–HCCB–TBM has been completed, the related materials’ preparation, mock-up manufacturing and tests have been implemented. The tungsten divertor has been studied with various bonding and coating technologies. Meanwhile, highlights of functional material for TBM, oxides and carbides dispersion strengthened (ODS, CDS) reduced activation ferritic/martensitic (RAFM) steel, vanadium and tungsten alloys are also presented.

Influence of combined impact and cyclic loading on the overall fatigue life of forged steel, EA4T

Energy Technology Data Exchange (ETDEWEB)

Malekzadeh, A.; Hadidi-Moud, S.; Farhangdoost, Kh [Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

2017-03-15

The performance of forged steel, EA4T, used in rail industry, under simulated in service conditions, i.e. combined impact - cyclic loading, was investigated through a comprehensive experimental programme. The standard Paris-Erdogan fatigue design curve parameters, m and C, were calibrated to account for the effect of the impact component of loading. A minimum threshold for impact load component, identified in the experiments, was also incorporated in the proposed empirical model. Comparison with experimental findings indicated that this “modified” Fatigue design curve could predict the fatigue life of pre impact loaded specimens with sufficient accuracy. It was therefore suggested that the modified model may be used as a novel design tool for predicting the overall fatigue life of components made of this material under the specified combined impact and fatigue loading conditions.

Developing of complex for hot plastic deformation modeling of steel type 20-30CrNiMoV for heavy forging

Directory of Open Access Journals (Sweden)

Dub Vladimir

2017-01-01

Full Text Available Production of heavy forging of bars weighing more then 235 tons for such products as rotors made of steel type 20-30CrNiMoV is a critical independent work, failure to perform which entails high costs related to repeated production (in case of defective product and untimely launch of production plants. One of the frequent causes of a defective product is the impossibility of ultrasonic testing in the barrel-gate zones on the rotor workpiece, which is due to the microstructure of the metal, namely the grain size. Determing the stages of deformation process wich causes such defects in structure is the main goal of this work.

Frontier Observatory for Research in Geothermal Energy: Phase 1 Topical Report Fallon, NV

Energy Technology Data Exchange (ETDEWEB)

Blankenship, Douglas A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Akerley, John [Ormat Nevada Inc., Reno, NV (United States); Blake, Kelly [U.S. Navy Geothermal Program Office, China Lake, CA (United States); Calvin, Wendy [Univ. of Nevada, Reno, NV (United States). Dept. of Geological Sciences and Engineering; Faulds, James E. [Univ. of Nevada, Reno, NV (United States). Nevada Bureau of Mines and Geology; Glen, Jonathan [U.S. Geological Survey, Menlo Park, CA (United States); Hickman, Stephen [U.S. Geological Survey, Menlo Park, CA (United States); Hinz, Nick [Univ. of Nevada, Reno, NV (United States). Nevada Bureau of Mines and Geology; Kaven, Ole [U.S. Geological Survey, Menlo Park, CA (United States); Lazaro, Mike [U.S. Navy Geothermal Program Office, China Lake, CA (United States); Meade, David [U.S. Navy Geothermal Program Office, China Lake, CA (United States); Kennedy, Mack [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phelps, Geoff [U.S. Geological Survey, Menlo Park, CA (United States); Sabin, Andrew [U.S. Navy Geothermal Program Office, China Lake, CA (United States); Schoenball, Martin [U.S. Geological Survey, Menlo Park, CA (United States); Silar, Drew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Robertson-Tait, Ann [GeothermEx/Schlumberger, Richmond, CA (United States); Williams, Colin [U.S. Geological Survey, Menlo Park, CA (United States)

2016-09-01

The Department of Energy (DOE) Frontier Observatory for Research in Geothermal Energy (FORGE) is to be a dedicated site where the subsurface scientific and engineering community can develop, test, and improve technologies and techniques for the creation of cost-effective and sustainable enhanced geothermal systems (EGS) in a controlled, ideal environment. The establishment of FORGE will facilitate development of an understanding of the key mechanisms controlling a successful EGS. Execution of FORGE is occurring in three phases with five distinct sub-phases (1, 2A, 2B, 2C, and 3). This report focuses on Phase 1 activities. During Phase 1, critical technical and logistical tasks necessary to demonstrate the viability of the Fallon FORGE Project site were completed and the commitment and capability of the Fallon FORGE team to execute FORGE was demonstrated. As part of Phase 1, the Fallon FORGE Team provided an assessment of available relevant data and integrated these geologic and geophysical data to develop a conceptual 3-D geologic model of the proposed test location. Additionally, the team prepared relevant operational plans for full FORGE implementation, provided relevant site data to the science and engineering community, engaged in outreach and communications with interested stakeholders, and performed a review of the environmental and permitting activities needed to allow FORGE to progress through Phase 3. The results of these activities are provided as Appendices to this report. The Fallon FORGE Team is diverse, with deep roots in geothermal science and engineering. The institutions and key personnel that comprise the Fallon FORGE Team provide a breadth of geoscience and geoengineering capabilities, a strong and productive history in geothermal research and applications, and the capability and experience to manage projects with the complexity anticipated for FORGE. Fallon FORGE Team members include the U.S. Navy, Ormat Nevada Inc., Sandia National Laboratories

Forging Hispanic communities in new destinations: A case study of Durham, NC.

Science.gov (United States)

Flippen, Chenoa A; Parrado, Emilio A

2012-03-01

The Chicago School of urban sociology and its extension in the spatial assimilation model have provided the dominant framework for understanding the interplay between immigrant social and spatial mobility. However, the main tenets of the theory were derived from the experience of pre-war, centralized cities; scholars falling under the umbrella of the Los Angeles school have recently challenged the extent to which they are applicable to the contemporary urban form, which is characterized by sprawling, decentralized, and multi-nucleated development. Indeed, new immigrant destinations, such as those scattered throughout the American Southeast, are both decentralized and lack prior experience with large scale immigration. Informed by this debate this paper traces the formation and early evolution of Hispanic neighborhoods in Durham, NC, a new immigrant destination. Using qualitative data we construct a social history of immigrant neighborhoods and apply survey and census information to examine the spatial pattern of neighborhood succession. We also model the sorting of immigrants across neighborhoods according to personal characteristics. Despite the many differences in urban form and experience with immigration, the main processes forging the early development of Hispanic neighborhoods in Durham are remarkably consistent with the spatial expectations from the Chicago School, though the sorting of immigrants across neighborhoods is more closely connected to family dynamics and political economy considerations than purely human capital attributes.

Microstructural and mechanical properties of AA1100 aluminum processed by multi-axial incremental forging and shearing

Energy Technology Data Exchange (ETDEWEB)

Montazeri-Pour, M. [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Advanced Metalforming and Thermomechanical Processing Laboratory, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Parsa, M.H., E-mail: mhparsa@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Advanced Metalforming and Thermomechanical Processing Laboratory, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Jafarian, H.R. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Taieban, S. [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of)

2015-07-15

Multi-axial incremental forging and shearing (MAIFS), as a new severe plastic deformation technique, was successfully applied up to eight passes on the workpieces of commercially pure Al (AA1100). The microstructure evolutions and mechanisms of the grain refinement in the billets deformed through various passes of process were studied using the electron backscatter diffraction (EBSD) analysis. Microhardness measurements and tensile tests were carried out to evaluate the mechanical properties and deformation behavior of the material after successive passes of the MAIFS process. Measured microhardness evolution indicated that while the distribution of hardness was non-uniform after odd-numbered passes up to four passes, but thereafter outstanding deformation homogeneity was achieved when the consecutive MAIFS passes were applied. Tensile tests indicated that yield stress and ultimate tensile strength increased rapidly during the primary pass of process but thereafter there was only a minor increase up to four passes. After that, a little drop could be observed in strength and then it reached to a saturated magnitude. Measured microhardness distribution values exhibited the same trend, viz. it increased through successive passes to a limiting value beyond which it showed a minor decline by disappearance of points having maximum hardness. Some coarsening was taken place and the dislocation walls between the boundaries were reduced significantly in going from four to six passes. It was suggested that the absorption of the dislocations into grain boundaries as an effective recovery process under large deformations and short-range migration of grain boundaries might be significant mechanisms responsible for the softening observed after four passes of process.

Microstructural and mechanical properties of AA1100 aluminum processed by multi-axial incremental forging and shearing

International Nuclear Information System (INIS)

Montazeri-Pour, M.; Parsa, M.H.; Jafarian, H.R.; Taieban, S.

2015-01-01

Multi-axial incremental forging and shearing (MAIFS), as a new severe plastic deformation technique, was successfully applied up to eight passes on the workpieces of commercially pure Al (AA1100). The microstructure evolutions and mechanisms of the grain refinement in the billets deformed through various passes of process were studied using the electron backscatter diffraction (EBSD) analysis. Microhardness measurements and tensile tests were carried out to evaluate the mechanical properties and deformation behavior of the material after successive passes of the MAIFS process. Measured microhardness evolution indicated that while the distribution of hardness was non-uniform after odd-numbered passes up to four passes, but thereafter outstanding deformation homogeneity was achieved when the consecutive MAIFS passes were applied. Tensile tests indicated that yield stress and ultimate tensile strength increased rapidly during the primary pass of process but thereafter there was only a minor increase up to four passes. After that, a little drop could be observed in strength and then it reached to a saturated magnitude. Measured microhardness distribution values exhibited the same trend, viz. it increased through successive passes to a limiting value beyond which it showed a minor decline by disappearance of points having maximum hardness. Some coarsening was taken place and the dislocation walls between the boundaries were reduced significantly in going from four to six passes. It was suggested that the absorption of the dislocations into grain boundaries as an effective recovery process under large deformations and short-range migration of grain boundaries might be significant mechanisms responsible for the softening observed after four passes of process

Possibilities for global governance of converging technologies

Science.gov (United States)

Roco, Mihail C.

2008-01-01

The convergence of nanotechnology, modern biology, the digital revolution and cognitive sciences will bring about tremendous improvements in transformative tools, generate new products and services, enable opportunities to meet and enhance human potential and social achievements, and in time reshape societal relationships. This paper focuses on the progress made in governance of such converging, emerging technologies and suggests possibilities for a global approach. Specifically, this paper suggests creating a multidisciplinary forum or a consultative coordinating group with members from various countries to address globally governance of converging, emerging technologies. The proposed framework for governance of converging technologies calls for four key functions: supporting the transformative impact of the new technologies; advancing responsible development that includes health, safety and ethical concerns; encouraging national and global partnerships; and establishing commitments to long-term planning and investments centered on human development. Principles of good governance guiding these functions include participation of all those who are forging or affected by the new technologies, transparency of governance strategies, responsibility of each participating stakeholder, and effective strategic planning. Introduction and management of converging technologies must be done with respect for immediate concerns, such as privacy, access to medical advancements, and potential human health effects. At the same time, introduction and management should also be done with respect for longer-term concerns, such as preserving human integrity, dignity and welfare. The suggested governance functions apply to four levels of governance: (a) adapting existing regulations and organizations; (b) establishing new programs, regulations and organizations specifically to handle converging technologies; (c) building capacity for addressing these issues into national policies and

Possibilities for global governance of converging technologies

International Nuclear Information System (INIS)

Roco, Mihail C.

2008-01-01

The convergence of nanotechnology, modern biology, the digital revolution and cognitive sciences will bring about tremendous improvements in transformative tools, generate new products and services, enable opportunities to meet and enhance human potential and social achievements, and in time reshape societal relationships. This paper focuses on the progress made in governance of such converging, emerging technologies and suggests possibilities for a global approach. Specifically, this paper suggests creating a multidisciplinary forum or a consultative coordinating group with members from various countries to address globally governance of converging, emerging technologies. The proposed framework for governance of converging technologies calls for four key functions: supporting the transformative impact of the new technologies; advancing responsible development that includes health, safety and ethical concerns; encouraging national and global partnerships; and establishing commitments to long-term planning and investments centered on human development. Principles of good governance guiding these functions include participation of all those who are forging or affected by the new technologies, transparency of governance strategies, responsibility of each participating stakeholder, and effective strategic planning. Introduction and management of converging technologies must be done with respect for immediate concerns, such as privacy, access to medical advancements, and potential human health effects. At the same time, introduction and management should also be done with respect for longer-term concerns, such as preserving human integrity, dignity and welfare. The suggested governance functions apply to four levels of governance: (a) adapting existing regulations and organizations; (b) establishing new programs, regulations and organizations specifically to handle converging technologies; (c) building capacity for addressing these issues into national policies and

Possibilities for global governance of converging technologies

Energy Technology Data Exchange (ETDEWEB)

Roco, Mihail C. [National Science Foundation (NSF) (United States)], E-mail: mroco@nsf.gov

2008-01-15

The convergence of nanotechnology, modern biology, the digital revolution and cognitive sciences will bring about tremendous improvements in transformative tools, generate new products and services, enable opportunities to meet and enhance human potential and social achievements, and in time reshape societal relationships. This paper focuses on the progress made in governance of such converging, emerging technologies and suggests possibilities for a global approach. Specifically, this paper suggests creating a multidisciplinary forum or a consultative coordinating group with members from various countries to address globally governance of converging, emerging technologies. The proposed framework for governance of converging technologies calls for four key functions: supporting the transformative impact of the new technologies; advancing responsible development that includes health, safety and ethical concerns; encouraging national and global partnerships; and establishing commitments to long-term planning and investments centered on human development. Principles of good governance guiding these functions include participation of all those who are forging or affected by the new technologies, transparency of governance strategies, responsibility of each participating stakeholder, and effective strategic planning. Introduction and management of converging technologies must be done with respect for immediate concerns, such as privacy, access to medical advancements, and potential human health effects. At the same time, introduction and management should also be done with respect for longer-term concerns, such as preserving human integrity, dignity and welfare. The suggested governance functions apply to four levels of governance: (a) adapting existing regulations and organizations; (b) establishing new programs, regulations and organizations specifically to handle converging technologies; (c) building capacity for addressing these issues into national policies and

Improvement of mechanical strength of sintered Mo alloyed steel by optimization of sintering and cold-forging processes with densification

Science.gov (United States)

Kamakoshi, Y.; Shohji, I.; Inoue, Y.; Fukuda, S.

2017-10-01

Powder metallurgy (P/M) materials have been expected to be spread in automotive industry. Generally, since sintered materials using P/M ones contain many pores and voids, mechanical properties of them are inferior to those of conventional wrought materials. To improve mechanical properties of the sintered materials, densification is effective. The aim of this study is to improve mechanical strength of sintered Mo-alloyed steel by optimizing conditions in sintering and cold-forging processes. Mo-alloyed steel powder was compacted. Then, pre-sintering (PS) using a vacuum sintering furnace was conducted. Subsequently, coldforging (CF) by a backward extrusion method was conducted to the pre-sintered specimen. Moreover, the cold-forged specimen was heat treated by carburizing, tempering and quenching (CQT). Afterwards, mechanical properties were investigated. As a result, it was found that the density of the PS specimen is required to be more than 7.4 Mg/m3 to strengthen the specimen by heat treatment after CF. Furthermore, density and the microstructure of the PS specimen are most important factors to make the high density and strength material by CF. At the CF load of 1200 kN, the maximum density ratio reached approximately 99% by the use of the PS specimen with proper density and microstructure. At the CF load of 900 kN, although density ratio was high like more than 97.8%, transverse rupture strength decreased sharply. Since densification caused high shear stress and stress concentration in the surface layer, microcracks occurred by the damages of inter-particle sintered connection of the surface layer. On the contrary, in case of the CF load of 1200 kN, ultra-densification of the surface layer occurred by a sufficient plastic flow. Such sufficient compressed specimens regenerated the sintered connections by high temperature heat treatment and thus the high strength densified material was obtained. These processes can be applicable to near net shape manufacturing

Back-pressure Forging Using a Servo Press

OpenAIRE

河本, 基一郎; Kawamoto, Kiichiro

2015-01-01

博士論文要旨Abstract　以下に掲載：International Journal of Automation Technology 9(2) pp.184-192 2015. Fuji Technology Press Ltd. 共著者：Kiichiro Kawamoto, Takeshi Yoneyama, Masato Okada

The influence of microstructure and operating temperature on the fatigue endurance of hot forged Inconel{sup ®} 718 components

Energy Technology Data Exchange (ETDEWEB)

Maderbacher, H., E-mail: hermann.maderbacher@unileoben.ac.at [Chair of Mechanical Engineering, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Oberwinkler, B., E-mail: bernd.oberwinkler@bohler-forging.com [Böhler Schmiedetechnik GmbH and Co KG, Mariazellerstraße 25, 8605 Kapfenberg (Austria); Gänser, H.-P., E-mail: hans-peter.gaenser@mcl.at [Materials Center Leoben Forschung GmbH, Roseggerstraße 12, 8700 Leoben (Austria); Tan, W., E-mail: wen.tan@unileoben.ac.at [Chair of Mechanical Engineering, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Rollett, M., E-mail: mathias.rollett@stud.unileoben.ac.at [Chair of Mechanical Engineering, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Stoschka, M., E-mail: michael.stoschka@stud.unileoben.ac.at [Chair of Mechanical Engineering, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria)

2013-11-15

The dependence of the fatigue behavior of hot-forged Inconel{sup ®} 718 aircraft components on the operating temperature and the material microstructure is investigated. To this purpose, possible correlations between a variety of tested microstructural parameters and the results from low-cycle fatigue (LCF) testing are analyzed using statistical methods. To identify the prevailing damage mechanisms, failure analyses are carried out on specimens tested at different temperatures. Optical and scanning electron microscopy are used for the inspection of surface crack networks and of the final fracture surface. In addition, energy dispersive X-ray (EDX) analyses are performed at the crack initiation sites to track down possible accumulations of alloying elements. The results are critically reviewed and used to propose a temperature and microstructure dependent fatigue model for predicting LCF ε⧸N-curves.

Parts on Demand: Evaluation of Approaches to Achieve Flexible Manufacturing Systems for Navy Partson Demand. Volume 1

Science.gov (United States)

1984-02-01

R&D efforts reviewed. The resulting assessment highlighted the generic enabling technologies and cross- cutting R&D projects required to focus current...supplied by spot buys, and which may generate Navy Inventory Control Numbers (NICN). Random samples of data were extracted from the Master Data File ( MDF ...isostatic presses, rotary forging (both hot and cold), investment casting, 0and hammer forging. Other techniques such as a laser sculpting and implosion

Modelling the influence of carbon content on material behavior during forging

Science.gov (United States)

Korpała, G.; Ullmann, M.; Graf, M.; Wester, H.; Bouguecha, A.; Awiszus, B.; Behrens, B.-A.; Kawalla, R.

2017-10-01

Nowadays the design of single process steps and even of whole process chains is realized by the use of numerical simulation, in particular finite element (FE) based methods. A detailed numerical simulation of hot forging processes requires realistic models, which consider the relevant material-specific parameters to characterize the material behavior, the surface phenomena, the dies as well as models for the machine kinematic. This data exists partial for several materials, but general information on steel groups depending on alloying elements are not available. In order to generate the scientific input data regarding to material modelling, it is necessary to take into account the mathematical functions for deformation behavior as well as recrystallization kinetic, which depends alloying elements, initial microstructure and reheating mode. Besides the material flow characterization, a detailed description of surface changes caused by oxide scale is gaining in importance, as these phenomena affect the material flow and the component quality. Experiments to investigate the influence of only one chemical element on the oxide scale kinetic and the inner structure at high temperatures are still not available. Most data concerning these characteristics is provided for the steel grade C45, so this steel will be used as basis for the tests. In order to identify the effect of the carbon content on the material and oxidation behavior, the steel grades C15 and C60 will be investigated. This paper gives first approaches with regard to the influence of the carbon content on the oxide scale kinetic and the flow stresses combined with the initial microstructure.

Effect of the Process Parameters on the Formability, Microstructure, and Mechanical Properties of Thin Plates Fabricated by Rheology Forging Process with Electromagnetic Stirring Method

Science.gov (United States)

Jin, Chul Kyu; Jang, Chang Hyun; Kang, Chung Gil

2014-01-01

A thin plate (150 × 150 × 1.2 mm) with embedded corrugation is fabricated using the rheoforming method. Semisolid slurry is created using the electromagnetic stirring (EMS) system, and the thin plate is made with the forging die at the 200-ton hydraulic press. The cross sections and microstructures of the slurry with and without stirring are examined. To investigate the effect of the process parameters on the formability, microstructure, and mechanical properties of thin plate the slurry is subjected to 16 types of condition for the forging experiment. The 16 types included the following conditions: Whether the EMS is applied or not, three fractions of the solid phase at 35, 45 and 55 pct; two compression velocities at 30 and 300 mm s-1; and four different compression pressures—100, 150, 200 and 250 MPa. The thin plate's formability is enhanced at higher punch velocity for compressing the slurry, and fine solid particles are uniformly distributed, which in turn, enhances the plate's mechanical properties. The pressure between 150 and 200 MPa is an appropriate condition to form thin plates. A thin plate without defects can be created when the slurry at 35 pct of the solid fraction (f s) was applied at the compression velocity of 300 mm s-1 and 150 MPa of pressure. The surface state of thin plate is excellent with 220 MPa of tensile strength and 13.5 pct of elongation. The primary particles are fine over the entire plate, and there are no liquid segregation-related defects.

Emerging landscape of accelerator science and technology

International Nuclear Information System (INIS)

Chattopadhyay, Swapan

2011-01-01

John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. In the second half of the twentieth century, we witnessed the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra-small structures and ultra-fast processes continues. We give a glimpse of the recent developments and innovations in the conception, production and control of charged particle beams in the service of scientific society. (author)

‘Mortgaged lives’: the biopolitics of debt and housing financialisation

OpenAIRE

Garcia Lamarca, Melissa; Kaika, Maria

2016-01-01

The paper expands the conceptual framework within which we examine mortgage debt by reconceptualising mortgages as a biotechnology: a technology of power over life that forges an intimate relationship between global financial markets, everyday life and human labour. Taking seriously the materiality of mortgage contracts as a means of forging new embodied practices of financialisation, we urge for the need to move beyond a policy? and macroeconomics?based analysis of housing financialisation. ...

Determination of interfacial heat transfer coefficient for TC11 titanium alloy hot forging

Science.gov (United States)

Lu, Baoshan; Wang, Leigang; Geng, Zhe; Huang, Yao

2017-10-01

In this paper, based on self-developed experimental apparatus, the upsetting test of TC11 titanium alloy on the hot flat die was conducted and Beck's nonlinear inverse estimation method was adopted to calculate the interfacial heat transfer coefficient (IHTC) and the change rules of IHTC following billet deformation rate, average interfacial temperature and holding time were investigated respectively. Experimental results indicate that IHTC increases with the increase of deformation rate as a whole, and the billet deformation heat and interfacial friction heat during forming that remarkably contribute to IHTC and the contributions by heat conduction to IHTC is differ from that by friction; the glass lubricant coated on the billet surface that weakens the heat transfer situation in the early stage of forging, however, this blocking effect of lubricant on IHTC soon vanishes with increasing deformation rate and it enhances the interface heat transfer later; the average interfacial temperature impacts on IHTC in many aspects and a high average interfacial temperature IHTC corresponds to a high IHTC when the deformation rate is certain, but this changing trend is not monotonous; the IHTC decreases with the increase of holding time due to oxidation. After certain holding time, the IHTC is only related to temperature and pressure in the absence of deformation rate, and the influence of pressure on IHTC is larger than that of temperature on it.

Forging Hispanic communities in new destinations: A case study of Durham, NC1

Science.gov (United States)

Flippen, Chenoa A.; Parrado, Emilio A.

2013-01-01

The Chicago School of urban sociology and its extension in the spatial assimilation model have provided the dominant framework for understanding the interplay between immigrant social and spatial mobility. However, the main tenets of the theory were derived from the experience of pre-war, centralized cities; scholars falling under the umbrella of the Los Angeles school have recently challenged the extent to which they are applicable to the contemporary urban form, which is characterized by sprawling, decentralized, and multi-nucleated development. Indeed, new immigrant destinations, such as those scattered throughout the American Southeast, are both decentralized and lack prior experience with large scale immigration. Informed by this debate this paper traces the formation and early evolution of Hispanic neighborhoods in Durham, NC, a new immigrant destination. Using qualitative data we construct a social history of immigrant neighborhoods and apply survey and census information to examine the spatial pattern of neighborhood succession. We also model the sorting of immigrants across neighborhoods according to personal characteristics. Despite the many differences in urban form and experience with immigration, the main processes forging the early development of Hispanic neighborhoods in Durham are remarkably consistent with the spatial expectations from the Chicago School, though the sorting of immigrants across neighborhoods is more closely connected to family dynamics and political economy considerations than purely human capital attributes. PMID:24482612

Rapid heating tensile tests of high-energy-rate-forged 316L stainless steel containing internal helium from radioactive decay of absorbed tritium

International Nuclear Information System (INIS)

Mosley, W.C.

1990-01-01

316L stainless steel is a candidate material for construction of equipment that will be exposed to tritium. This austenitic stainless steel is frequently used in the high-energy-rate-forged (HERF) metallurgical condition to take advantage of increased strength produced by cold work introduced by this process. Proper design of tritium-handling equipment will require an understanding of how helium-3, the product of radioactive decay of tritium, affects mechanical properties. This report describes results of elevated-temperature tensile testing of HERF 316L stainless steel specimens containing helium concentrations of 171 (calculated) atomic parts per million (appm). Results are compared with those reported previously for specimens containing 0 and 94 (measured) appm helium

Building a science of partnership-focused research: forging and sustaining partnerships to support child mental health prevention and services research.

Science.gov (United States)

Bradshaw, Catherine P; Haynes, Katherine Taylor

2012-07-01

Building on growing interest in translational research, this paper provides an overview of a special issue of Administration and Policy in Mental Health and Mental Health Service Research, which is focused on the process of forging and sustaining partnerships to support child mental health prevention and services research. We propose that partnership-focused research is a subdiscipline of translational research which requires additional research to better refine the theoretical framework and the core principles that will guide future research and training efforts. We summarize some of the major themes across the eight original articles and three commentaries included in the special issue. By advancing the science of partnership-focused research we will be able to bridge the gap between child mental health prevention and services research and practice.

Spray forming and mechanical properties of a new type powder metallurgy superalloy

International Nuclear Information System (INIS)

Jia Chong-Lin; Ge Chang-Chun; Xia Min; Gu Tian-Fu

2015-01-01

The deposited billet of a new type powder metallurgy (PM) superalloy FGH4095M for use in turbine disk manufacturing has been fabricated using spray forming technology. The metallurgical quality of the deposited billet was analyzed in terms of density, texture, and grain size. Comparative research was done on the microstructure and mechanical properties between the flat disk preform prepared with hot isostatic pressing (HIP) and the same alloy forgings prepared with HIP followed by isothermal forging (IF). The results show that the density of the spray-formed and nitrogen-atomized deposit billet is above 99% of the theoretical density, indicating a compact structure. The grains are uniform and fine. The billet has weak texture with a random distribution in the spray deposition direction and perpendicular to the direction of deposition. A part of atomizing nitrogen exists in the preform in the form of carbonitride. Nitrogen-induced microporosity causes the density reduction of the preform. Compared with the process of HIP+IF, the superalloy FGH4095M after HIP has better mechanical properties at both room temperature and high temperature. The sizes of the γ′ phase are finer in microstructure of the preform after HIP in comparison with the forgings after HIP+IF. This work shows that SF+HIP is a viable processing route for FGH4095M as a turbine-disk material. (paper)

A theoretical reflection on the implications of the philosophy of technology for teacher education.

Directory of Open Access Journals (Sweden)

Piet Ankiewicz

2013-02-01

Full Text Available Since the implementation of technology as relatively new school subject, challenges are constantly being posed to higher education institutions (HEIs, and in particular those engaged in teacher training and the professional development of technology teachers. Teacher training programmes had to be developed and implemented within a limited time frame in comparison to other school subjects, despite a lack of previous experience of an appropriate academic discipline, subject methodology and classroom pedagogy. Furthermore, implications on organisational and managerial level regarding its accommodation within existing structures of faculties, schools and departments at HEIs had to be accounted for. The purpose of the article was to investigate how a scientifically founded philosophical framework of technology might guide teacher training at HEIs. The following research questions served as point of departure: in which way can a scientifically founded philosophical framework of technology be indicative regarding a relevant: (1 Subject methodology of technology? (2 Underlying academic discipline for undergraduate technology education students? In answer to the first question, it was found that it is important for programme developers, coordinators and subject methodology lecturers at HEIs to acquaint themselves sufficiently with a philosophical framework for technology to direct the technology teacher’s training and professional development. It seems viable to keep subject methodology of technology autonomous, with only one lecturer responsible, and that technology education students should be conversant in the philosophical framework for technology. In answer to the second question HEIs should urgently determine the nature and composition of the relevant academic disciplines underpinning the undergraduate qualification of a specialised technology teacher. Mechanisms should also be created to forge a relationship between the academic discipline and

Talking with TV shows

DEFF Research Database (Denmark)

Sandvik, Kjetil; Laursen, Ditte

2014-01-01

User interaction with radio and television programmes is not a new thing. However, with new cross-media production concepts such as X Factor and Voice, this is changing dramatically. The second-screen logic of these productions encourages viewers, along with TV’s traditional one-way communication...... mode, to communicate on interactive (dialogue-enabling) devices such as laptops, smartphones and tablets. Using the TV show Voice as our example, this article shows how the technological and situational set-up of the production invites viewers to engage in new ways of interaction and communication...

Evaluation of microstructure and mechanical properties of 50Cr5NiMoV steel for forged backup roll

Energy Technology Data Exchange (ETDEWEB)

Song, X.Y.; Zhang, X.J.; Fu, L.C.; Yang, H.B.; Yang, K.; Zhu, L., E-mail: zl508@126.com

2016-11-20

The microstructure and mechanical properties of forged 50Cr5NiMoV steel backup roll were evaluated in this study. The microstructure characteristics from surface to center along radial direction of the backup roll were carefully observed by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the chemical composition, hardness, tensile property, impact and fracture toughness in different position of the backup roll were also examined. The results indicate that the finely precipitated carbides at different matrix during heat treatment process strongly influence mechanical properties of the backup roll. Especially, the spheroidized pearlite at the inner regions which consists of large globular or rod-like M{sub 7}C{sub 3} and a little of small globular M{sub 23}C{sub 6} possesses much better toughness and fracture resistance properties than those of the lamellar pearlite with lamellar M{sub 23}C{sub 6} and a little of globular M{sub 7}C{sub 3}.

The effect of advanced ultrasonic forging on fatigue fracture mechanisms of welded Ti-6A1-4V alloy

Science.gov (United States)

Smirnova, A.; Pochivalov, Yu.; Panin, V.; Panin, S.; Eremin, A.; Gorbunov, A.

2017-12-01

The current study is devoted to application of advanced postwelding ultrasonic forging to joints formed by laser welding of Ti-6A1-4V alloy in order to enhance their mechanical properties and fatigue durability. Low cycle fatigue tests were performed via digital image correlation technique used to obtain strain fields and in situ characterization of deformation, crack growth and fracture. Fracture surfaces were studied by SEM analysis accompanied with calculation of fracture patterns percentage. The fatigue tests demonstrate the high increase in the number of cycles until fracture (from 17 000 to 32 000 cycles) which could be explained by high ductility of welded material after treatment. This leads to lower fatigue crack growth rate due to higher energy dissipation. The obtained effect is attributable only for small cracks on micro-/mesoscales and fails to play a significant role for macro cracks.

The Bright Elusive Butterfly of Value in Health Technology Development; Comment on “Providing Value to New Health Technology: The Early Contribution of Entrepreneurs, Investors, and Regulatory Agencies”

Directory of Open Access Journals (Sweden)

Trisha Greenhalgh

2018-01-01

Full Text Available The current system of health technology development is characterised by multiple misalignments. The “supply” side (innovation policy-makers, entrepreneurs, investors and the “demand” side (health policy-makers, regulators, health technology assessment, purchasers operate under different – and conflicting – logics. The system is less a “pathway” than an unstable ecosystem of multiple interacting sub-systems. “Value” means different things to each of the numerous actors involved. Supply-side dynamics are built on fictions; regulatory checks and balances are designed to assure quality, safety and efficacy, not to ensure that technologies entering the market are either desirable or cost-effective. Assessment of comparative and cost-effectiveness usually comes too late in the process to shape an innovation’s development. We offer no simple solutions to these problems, but in the spirit of commencing a much-needed public debate, we suggest some tentative ways forward. First, universities and public research funders should play a more proactive role in shaping the system. Second, the role of industry in forging long-term strategic partnerships for public benefit should be acknowledged (though not uncritically. Third, models of “responsible innovation” and public input to research priority-setting should be explored. Finally, the evidence base on how best to govern inter-sectoral health research partnerships should be developed and applied.

Developing community-driven quality improvement initiatives to enhance chronic disease care in Indigenous communities in Canada: the FORGE AHEAD program protocol.

Science.gov (United States)

Naqshbandi Hayward, Mariam; Paquette-Warren, Jann; Harris, Stewart B

2016-07-26

Given the dramatic rise and impact of chronic diseases and gaps in care in Indigenous peoples in Canada, a shift from the dominant episodic and responsive healthcare model most common in First Nations communities to one that places emphasis on proactive prevention and chronic disease management is urgently needed. The Transformation of Indigenous Primary Healthcare Delivery (FORGE AHEAD) Program partners with 11 First Nations communities across six provinces in Canada to develop and evaluate community-driven quality improvement (QI) initiatives to enhance chronic disease care. FORGE AHEAD is a 5-year research program (2013-2017) that utilizes a pre-post mixed-methods observational design rooted in participatory research principles to work with communities in developing culturally relevant innovations and improved access to available services. This intensive program incorporates a series of 10 inter-related and progressive program activities designed to foster community-driven initiatives with type 2 diabetes mellitus as the action disease. Preparatory activities include a national community profile survey, best practice and policy literature review, and readiness tool development. Community-level intervention activities include community and clinical readiness consultations, development of a diabetes registry and surveillance system, and QI activities. With a focus on capacity building, all community-level activities are driven by trained community members who champion QI initiatives in their community. Program wrap-up activities include readiness tool validation, cost-analysis and process evaluation. In collaboration with Health Canada and the Aboriginal Diabetes Initiative, scale-up toolkits will be developed in order to build on lessons-learned, tools and methods, and to fuel sustainability and spread of successful innovations. The outcomes of this research program, its related cost and the subsequent policy recommendations, will have the potential to

Development of Improved Design and 3D Printing Manufacture of Cross-Flow Fan Rotor

Science.gov (United States)

2016-06-01

printer was used to print components of a carbon-fiber composite cross-flow fan rotor . These pieces were assembled and the thrust, power, and thrust...variables. A MarkForged Mark One 3D printer was used to print components of a carbon-fiber composite cross-flow fan rotor . These pieces were assembled... composite parts to be 3D printed. This technology showed promise in rapidly manufacturing complicated blade and rotor geometries. The objective of

On the Role of Processing Parameters in Producing Recycled Aluminum AA6061 Based Metal Matrix Composite (MMC-AlR Prepared Using Hot Press Forging (HPF Process

Directory of Open Access Journals (Sweden)

Azlan Ahmad

2017-09-01

Full Text Available Solid-state recycling, which involves the direct recycling of scrap metal into bulk material using severe plastic deformation, has emerged as a potential alternative to the conventional remelting and recycling techniques. Hot press forging has been identified as a sustainable direct recycling technique that has fewer steps and maintains excellent material performance. An experimental investigation was conducted to explore the hardness and density of a recycled aluminum-based metal matrix composite by varying operating temperature and holding time. A mixture of recycled aluminum, AA6061, and aluminum oxide were simultaneously heated to 430, 480, and 530 °C and forged for 60, 90, and 120 min. We found a positive increase in microhardness and density for all composites. The hardness increased approximately 33.85%, while density improved by about 15.25% whenever the temperature or the holding time were increased. Based on qualitative analysis, the composite endures substantial plastic deformation due to the presence of hardness properties due to the aluminum oxide embedded in the aluminum matrix. These increases were significantly affected by the operating temperature; the holding time also had a subordinate role in enhancing the metal matrix composite properties. Furthermore, in an effort to curb the shortage of primary resources, this study reviewed the promising performance of secondary resources produced by using recycled aluminum and aluminum oxide as the base matrix and reinforcement constituent, respectively. This study is an outline for machining practitioners and the manufacturing industry to help increase industry sustainability with the aim of preserving the Earth for our community in the future.

On the Role of Processing Parameters in Producing Recycled Aluminum AA6061 Based Metal Matrix Composite (MMC-AlR) Prepared Using Hot Press Forging (HPF) Process.

Science.gov (United States)

Ahmad, Azlan; Lajis, Mohd Amri; Yusuf, Nur Kamilah

2017-09-19

Solid-state recycling, which involves the direct recycling of scrap metal into bulk material using severe plastic deformation, has emerged as a potential alternative to the conventional remelting and recycling techniques. Hot press forging has been identified as a sustainable direct recycling technique that has fewer steps and maintains excellent material performance. An experimental investigation was conducted to explore the hardness and density of a recycled aluminum-based metal matrix composite by varying operating temperature and holding time. A mixture of recycled aluminum, AA6061, and aluminum oxide were simultaneously heated to 430, 480, and 530 °C and forged for 60, 90, and 120 min. We found a positive increase in microhardness and density for all composites. The hardness increased approximately 33.85%, while density improved by about 15.25% whenever the temperature or the holding time were increased. Based on qualitative analysis, the composite endures substantial plastic deformation due to the presence of hardness properties due to the aluminum oxide embedded in the aluminum matrix. These increases were significantly affected by the operating temperature; the holding time also had a subordinate role in enhancing the metal matrix composite properties. Furthermore, in an effort to curb the shortage of primary resources, this study reviewed the promising performance of secondary resources produced by using recycled aluminum and aluminum oxide as the base matrix and reinforcement constituent, respectively. This study is an outline for machining practitioners and the manufacturing industry to help increase industry sustainability with the aim of preserving the Earth for our community in the future.

The effect of hot working on structure and strength of a precipitation strengthened austenitic stainless steel

International Nuclear Information System (INIS)

Mataya, M.C.; Carr, M.J.; Krauss, G.

1984-01-01

The development of microstructure and strength during forging a γ' strengthened austenitic stainless steel, JBK-75, was investigated. The specimens were deformed in a strain range of 0.16 to 1.0, from 800 0 C to 1080 0 C at approximate strain rates of 2 (press forging) and 2 X 10 3 S -1 (high energy rate forging). Mechanical properties were determined by tensile testing as-forged and forged and aged specimens. The alloy exhibited a wide variety of structures and properties within the range of forging parameters studied. Deformation at the higher strain rate via high energy rate forging resulted in unrecovered substructures and high strengths at low forging temperatures, and static recrystallization and low strengths at high temperatures. In contrast, however, deformation at the lower strain rate via press forging resulted in retention of the well developed subgrain structure and associated high strength produced at high forging temperatures and strains. At lower temperatures and strains during press forging a subgrain structure formed preferentially at high angle grain boundaries, apparently by a creep-type deformation mechanism. Dynamic recrystallization was not an important restoration mechanism for any of the forging conditions. The results are interpreted on the basis of stacking fault energy and the accumulation of strain energy during hot working. The significance of microstructural differences for equivalent deformation conditions (iso-Z, where Z is the Zener-Holloman parameter) is discussed in relation to the utilization of Z for predicting hot work structures and strengths. Aging showed that γ' precipitation is not affected by substructure and that the strengthening contributions were independent and additive. Applications for these findings are discussed in terms of process design criteria

Effect of composition, heat treatment and processing technologies on the microstructure and properties of HP and IP rotors of large steam turbines from 1CrMoV steels

Energy Technology Data Exchange (ETDEWEB)

Tchizhik, A A [The Polzunov Central Boiler and Turbine Institute, Department the Fatigue Life of Materials for Power Plant Equipment, St. Petersburg (Russian Federation)

1999-12-31

In the presentation the evolution of the technology manufacturing of the large forging from the 1CrMoV steels and the results complex of the long time investigations rotors on virgin state and after different operation times is analyzed. Among the information there are the criterion of the optimization of the composition steel service properties, especially super long - term creep resistance, creep fracture and long time cracks resistance. Two safety coefficients: stress (SSC) and time safety coefficient (TSC) must be used for calculations of the possibility prolongation service life of HP and IP rotors for large steam turbines. (orig.) 11 refs.

Effect of composition, heat treatment and processing technologies on the microstructure and properties of HP and IP rotors of large steam turbines from 1CrMoV steels

Energy Technology Data Exchange (ETDEWEB)

Tchizhik, A.A. [The Polzunov Central Boiler and Turbine Institute, Department the Fatigue Life of Materials for Power Plant Equipment, St. Petersburg (Russian Federation)

1998-12-31

In the presentation the evolution of the technology manufacturing of the large forging from the 1CrMoV steels and the results complex of the long time investigations rotors on virgin state and after different operation times is analyzed. Among the information there are the criterion of the optimization of the composition steel service properties, especially super long - term creep resistance, creep fracture and long time cracks resistance. Two safety coefficients: stress (SSC) and time safety coefficient (TSC) must be used for calculations of the possibility prolongation service life of HP and IP rotors for large steam turbines. (orig.) 11 refs.

Final report of the Conference on Forging North American Energy Security

International Nuclear Information System (INIS)

2004-06-01

This paper discussed the main themes of the Forging American Energy Security Forum. The factors that may contribute to a potential energy crisis were identified as being the major blackout affecting the American Northeast and Ontario, political tensions in the Middle East, the volatility of oil and natural gas prices, fear of terrorist attacks on energy infrastructures and attempts to reform the Mexican energy sector. The conference addressed issues such as the reliability and physical integrity of the North American power supply grids, supply of energy at a stable and competitive price, growth of energy autonomy through increasing North American power supply and energy efficiency and the development of interconnections between power grids in the three countries. Diversification of energy supply sources was discussed, with particular reference to the increased use of renewable energies. Improvements in efficiency were suggested for how different levels of government interact on issues concerning energy development. It was recommended that the energy sector could serve as a springboard to implement a North American investment fund, and that Mexico should take advantage of its energy resources to attract foreign investors in order to finance an increase in Mexican energy production. It was suggested that a trilateral strategy aiming for energy security would accelerate national objectives. The fact that Mexico imports energy from the United States even though it already has the energy resources was also examined. Lack of capital in Mexico was seen as an impediment to development. It was concluded that relaxing regulations would facilitate in the management of the energy sector. The challenges of using clean energy sources were highlighted, as well the difficulties associated with establishing an integrated market for tradable renewable energy certificates. refs., figs

Final report of the Conference on Forging North American Energy Security

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-06-01

This paper discussed the main themes of the Forging American Energy Security Forum. The factors that may contribute to a potential energy crisis were identified as being the major blackout affecting the American Northeast and Ontario, political tensions in the Middle East, the volatility of oil and natural gas prices, fear of terrorist attacks on energy infrastructures and attempts to reform the Mexican energy sector. The conference addressed issues such as the reliability and physical integrity of the North American power supply grids, supply of energy at a stable and competitive price, growth of energy autonomy through increasing North American power supply and energy efficiency and the development of interconnections between power grids in the three countries. Diversification of energy supply sources was discussed, with particular reference to the increased use of renewable energies. Improvements in efficiency were suggested for how different levels of government interact on issues concerning energy development. It was recommended that the energy sector could serve as a springboard to implement a North American investment fund, and that Mexico should take advantage of its energy resources to attract foreign investors in order to finance an increase in Mexican energy production. It was suggested that a trilateral strategy aiming for energy security would accelerate national objectives. The fact that Mexico imports energy from the United States even though it already has the energy resources was also examined. Lack of capital in Mexico was seen as an impediment to development. It was concluded that relaxing regulations would facilitate in the management of the energy sector. The challenges of using clean energy sources were highlighted, as well the difficulties associated with establishing an integrated market for tradable renewable energy certificates. refs., figs.

Characteristics comparison of weld metal zones welded to cast and forged steels for piston crown material

Science.gov (United States)

Moon, Kyung-Man; Kim, Yun-Hae; Lee, Myeong-Hoon; Baek, Tae-Sil

2015-03-01

An optimum repair welding for the piston crown which is one of the engine parts exposed to the combustion chamber is considered to be very important to prolong the engine lifetime from an economical point of view. In this study, two types of filler metals such as 1.25Cr-0.5Mo, 0.5Mo were welded with SMAW method and the other two types of filler metals such as Inconel 625 and 718 were welded with GTAW method, respectively, and the used base metals were the cast and forged steels of the piston crown material. The weld metal zones welded with Inconel 625 and 718 filler metals exhibited higher corrosion resistance compared to 1.25Cr-0.5Mo and 0.5Mo filler metals. In particular, the weld metal zone welded with Inconel 718 and 0.5Mo, filler metals indicated the best and worst corrosion resistance, respectively. Consequently, it is suggested that the corrosion resistance of the weld metal zone surely depends on the chemical components of each filler metal and welding method irrespective of the types of piston crown material.

2015 Accomplishments-Tritium aging studies on stainless steel. Effects of hydrogen isotopes, crack orientation, and specimen geometry on fracture toughness

Energy Technology Data Exchange (ETDEWEB)

Morgan, Michael J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-01-01

This study reports on the effects of hydrogen isotopes, crack orientation, and specimen geometry on the fracture toughness of stainless steels. Fracture toughness variability was investigated for Type 21-6-9 stainless steel using the 7K0004 forging. Fracture toughness specimens were cut from the forging in two different geometric configurations: arc shape and disc shape. The fracture toughness properties were measured at ambient temperature before and after exposure to hydrogen gas and compared to prior studies. There are three main conclusions that can be drawn from the results. First, the fracture toughness properties of actual reservoir forgings and contemporary heats of steel are much higher than those measured in earlier studies that used heats of steel from the 1980s and 1990s and forward extruded forgings which were designed to simulate reservoir microstructures. This is true for as-forged heats as well as forged heats exposed to hydrogen gas. Secondly, the study confirms the well-known observation that cracks oriented parallel to the forging grain flow will propagate easier than those oriented perpendicular to the grain flow. However, what was not known, but is shown here, is that this effect is more pronounced, particularly after hydrogen exposures, when the forging is given a larger upset. In brick forgings, which have a relatively low amount of upset, the fracture toughness variation with specimen orientation is less than 5%; whereas, in cup forgings, the fracture toughness is about 20% lower than that forging to show how specimen geometry affects fracture toughness values. The American Society for Testing Materials (ASTM) specifies minimum specimen section sizes for valid fracture toughness values. However, sub-size specimens have long been used to study tritium effects because of the physical limitation of diffusing hydrogen isotopes into stainless steel at mild temperatures so as to not disturb the underlying forged microstructure. This study shows

Importance and role of grain size in free surface cracking prediction of heavy forgings

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhenhua [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Key Laboratory of Advanced Forging & Stamping Technology and Science, Yanshan University, Ministry of Education of China, Qinhuangdao 066004 (China); Sun, Shuhua; Wang, Bo [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Shi, Zhongping [Key Laboratory of Advanced Forging & Stamping Technology and Science, Yanshan University, Ministry of Education of China, Qinhuangdao 066004 (China); Fu, Wantang, E-mail: wtfu@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

2015-02-11

The importance and role of grain size in predicting surface cracking of heavy forgings were investigated. 18Mn18Cr0.5N steel specimens with four different grain sizes were tensioned between 900 and 1100 °C at a strain rate of 0.1 s{sup −1}. The nucleation sites and crack morphology were analyzed through electron backscatter diffraction analysis, and the fracture morphology was examined using scanning electron microscopy. The nucleation sites were independent of the grain size, and cracks primarily formed at grain boundaries and triple junctions between grains with high Taylor factors. Grains with lower Taylor factors inhibited crack propagation. Strain was found to mainly concentrate near the grain boundaries; thus, a material with a larger grain size cracks more easily because there are fewer grain boundaries. Fine grains can be easily rotated to a lower Taylor factor to further inhibit cracking. The fracture morphology transformed from a brittle to ductile type with a lowering of grain size. At lower temperature, small dimples on the fracture surfaces of specimens with smaller grain sizes were left by single parent grains and the dimple edge was the grain edge. At higher temperature, dimples formed through void coalescence and the dimple edge was the tearing edge. Finally, the relationship between the reduction in area, grain size, and deformation temperature was obtained.

Premature failure analysis of forged cold back-up roll in a continuous tandem mill

International Nuclear Information System (INIS)

Rad, Hamid Reza Bakhsheshi; Monshi, Ahmad; Idris, Mohd Hasbullah; Kadir, Mohammed Rafiq Abdul; Jafari, Hassan

2011-01-01

Highlights: → Metal wrapping and strip welding in work/back-up rolls contact zone caused spalling. → MnS inclusion and pore initiated crack which propagated in milling led to spalling. → Retained austenite conversion to α'-martensite accelerated spalling failure. → Needle shaped carbide (Fe,Mo,Cr) 7 C 3 , may cause poor service life of back-up roll. -- Abstract: In this paper, premature failure of a forged back-up roll from a continuous tandem mill was investigated. Microstructural evolutions of the spalled specimen and surface of the roll were characterized by optical microscopy, X-ray diffraction, scanning electron microscopy and ferritscopy, while hardness value of the specimen was measured by Vickers hardness testing. The results revealed that the presence of pore and MnS inclusion with spherical and oval morphologies were the main contributing factors responsible for the poor life of the back-up roll. In addition, metal pick up and subsequently strip welding on the surface of the work roll were found as the major causes of failure in work roll which led to spalling occurrence in the back-up roll. Furthermore, relatively high percentage of retained austenite, say 9%, in outer surface of the back-up roll contributed spalling due to conversion of this meta-stable phase to martensite and creation of volume expansion on the outer surface through work hardening during mill campaign.

Fracture Failure Analysis of Fuel Pump Transmission Shaft of Dual-Fuel Engine

Directory of Open Access Journals (Sweden)

Chen Pei-hong

2017-01-01

Full Text Available NTS6ZLCz-129 dual-fuel turbocharged and intercooled engine durability test at 1000h, fuel pump shaft fractured. Fracture analysis, chemical analysis, microstructure examination and finite element stress analysis were carried out on the fractured shaft. The analysis result showed that the shaft fracture cause is forging fold. By improving the forging process, the forging fold was solved, and the durability test can be carried out smoothly.

The Effect of Hot Working on Structure and Strength of a Precipitation Strengthened Austenitic Stainless Steel

Science.gov (United States)

Mataya, M. C.; Carr, M. J.; Krauss, G.

1984-02-01

The development of microstructure and strength during forging in a γ' strengthened austenitic stainless steel, JBK-75, was investigated by means of forward extrusion of cylindrical specimens. The specimens were deformed in a strain range of 0.16 to 1.0, from 800°C to 1080°C, and at approximate strain rates of 2 (press forging) and 2 × 103 s-1 (high energy rate forging), and structures examined by light and transmission microscopy. Mechanical properties were determined by tensile testing as-forged and forged and aged specimens. The alloy exhibited an extremely wide variety of structures and properties within the range of forging pzrameters studied. Deformation at the higher strain rate via high energy rate forging resulted in unrecovered substructures and high strengths at low forging temperatures, and static recrystallization and low strengths at high temperatures. In contrast, however, deformation at the lower strain rate via press forging resulted in retention of the well developed subgrain structure and associated high strength produced at high forging temperatures and strains. At lower temperatures and strains during press forging a subgrain structure formed preferentially at high angle grain boundaries, apparently by a creep-type deformation mechanism. Dynamic recrystallization was not an important restoration mechanism for any of the forging conditions. The results are interpreted on the basis of stacking fault energy and the accumulation of strain energy during hot working. The significance of observed microstructural differences for equivalent deformation conditions (iso-Z, where Z is the Zener-Holloman parameter) is discussed in relation to the utilization of Z for predicting hot work structures and strengths. Aging showed that the γ' precipitation process is not affected by substructure and that the strengthening contributions, from substructure and precipitation, were independent and additive. Applications for these findings are discussed in terms

Japan Report, Science and Technology.

Science.gov (United States)

1987-04-03

substances from plants Removal of fats and oils from snacks , such as potato chips Separation of chemical materials from natural resources Separation of...mechanically, and will be molded in order to make an ingot. This ingot will be worked plastically, i.e., extruded or forged with a view to variously...ym. Also to be noted, is that the extruded undulations are prone to erode polyethylene. Yamamoto: Since surface roughness of alumina is 0.04 ym or

The Invisible Hand of Innovation showing in the General Purpose Technology of Electricity

NARCIS (Netherlands)

van der Kooij, B.J.G.

2017-01-01

The unintended economic effect on society as result of individual behaviour —Adam Smith’s ‘Invisible Hand’ of economic progress in the eighteenth century — had its equivalent in technological progress. In the nineteenth century, again individual behaviour with its Acts of Innovation and Acts of

Research Facility for Mechanical Press Closed Gap Adjuster

Directory of Open Access Journals (Sweden)

A. A. Ancifirov

2016-01-01

Full Text Available The article describes an example of the research facility for closed gap adjustment mechanism based on the KD2128 closed-die forging press. Its rated force with a servo drive used is 630kN. The servo drive consists of a motor with nominal power of 1.57kW and a frequency converter with power of 7.5kW, which has functions of the programmable logic controller.The article notes that such a facility is expedient and useful for practical classes on forging-andstamping machines at the BMSTU Department of «Technology processing by pressure» to demonstrate the capabilities of existing technological facility, learn a design of forging-andstamping machine units, solve the problems of automatic control, monitoring, and diagnostics in blank manufacturing.The article presents a detailed facility diagram of the closed gap adjustment mechanism and its photograph, describes the mechanism and its basic parameters, gives characteristics of the synchronous motor to drive the mechanism, reviews practical works, which the research facility may provide.Based on the four experiments the article estimates an efficiency of the research facilityuse under consideration, especially when modeling a servo motor shaft under the maximum load. The relevant diagrams confirm experimental results, namely: control current, angle of motor shaft and its speed versus time. Thus, upon the diagram analysis it can be noted that the research facility design allows providing kinematics and dynamics of the press closed gap adjuster.This article describes how to determine the closed gap adjusting accuracy of the press. Eight experiments have been conducted to evaluate a working out control signal to the linear movement of the press punch when using the research facility. It is noted that the linear positioning accuracy of the press punch reaches the hundredth parts of a millimeter of the adjustment value that is sufficient to achieve the required precision when performing operations such as

Availability and Use of Telecommunication/Computer Information ...

African Journals Online (AJOL)

buz_centr_03

the study area, identify Information and Communication Technologies (ICTs) in telecommunication/computer .... recommended that extension should forge new links and create network for sharing knowledge and experience .... Food Security.

Tests for manufacturing technology of disposal canisters for nuclear spent fuel

International Nuclear Information System (INIS)

Raiko, H.; Salonen, T.; Meuronen, I.; Lehto, K.

1999-06-01

The summary and status of the results of the manufacturing technology programmes concerning the disposal canister for spent nuclear fuel conducted by Posiva Oy are given in this report. Posiva has maintained a draft plan for a disposal canister design and an assessment of potential manufacturing technologies for about ten years in Finland. Now, during the year 1999, the first full scale demonstration canister is manufactured in Finland. The technology used for manufacturing of this prototype is developed by Posiva Oy mainly in co-operation with domestic industry. The main partner in developing the manufacturing technology for the copper shell has been Outokumpu Poricopper Oy, Pori, Finland, and the main partner in developing the technology for the iron insert of the canister has been Valmet Oyj Rautpohja Foundry, Jyvaeskylae, Finland. In both areas many subcontractors have been used, predominantly domestic engineering workshops, but also some foreign subcontractors, e.g. for EB-welding, who have had large enough welding equipment. This report describes the developing programmes for canister manufacturing, evaluates the results and presents some alternative methods, and tries to evaluate the pros and contras of them. In addition, the adequacy of the achieved technological know-how is assessed in respect of the required quality of the disposal canister. The following manufacturing technologies have been the concrete topics of the development programme: Electron beam welding technology development for thick-walled copper, Casting of massive copper billets, Hot rolling of thick-walled copper plates, Hot pressing and forging in lid manufacture, Extrusion and drawing of copper tubes, Bending of copper plates by roller or press, Machining of copper, Residual stress removal by heat treatment, Non-destructive testing, Long-term strength of EB-welds, Casting and machining of the iron insert of the canister The specialists from all the main developing partner companies have

Numerical Simulation of Damage during Forging with Superimposed Hydrostatic Pressure by Active Media

International Nuclear Information System (INIS)

Behrens, B.-A.; Hagen, T.; Roehr, S.; Sidhu, K. B.

2007-01-01

The effective reduction of energy consumption and a reasonable treatment of resources can be achieved by minimizing a component's weight using lightweight metals. In this context, aluminum alloys play a major role. Due to their material-sided restricted formability, the mentioned aluminum materials are difficult to form. The plasticity of a material is ascertained by its maximum forming limit. It is attained, when the deformation causes mechanical damage within the material. Damage of that sort is reached more rapidly, the greater the tensile strength rate in relation to total tension rate. A promising approach of handling these low ductile, high-strength aluminum alloys within a forming process, is forming with a synchronized superposition of comprehensive stress by active media such as by controlling oil pressure. The influence of superimposed hydrostatic pressure on the flow stress was analyzed as well as the formability for different procedures at different hydrostatic pressures and temperature levels. It was observed that flow stress is independent of superimposed hydrostatic pressure. Neither the superimposed pressure has an influence on the plastic deformation, nor does a pressure dependent material hardening due to increasing hydrostatic pressure take place. The formability increases with rising hydrostatic pressure. The relative gain at room temperature and increase of the superimposed pressure from 0 to 600 bar for tested materials was at least 140 % and max. 220 %. Therefore in this paper, based on these experimental observations, it is the intended to develop a numerical simulation in order to predict ductile damage that occurs in the bulk forging process with superimposed hydrostatic pressure based Lemaitre's damage model

Forging Industry-Academic Alliances

Directory of Open Access Journals (Sweden)

Joseph M. Woodside

2014-08-01

Full Text Available With ever increasing amounts of data, organizations are identifying the importance of Business Intelligence (BI and Analytics for decision making. However in order to realize the full potential of these technologies, organizations require well-trained and educated management and analytic subject matter experts to transform the data and results into actionable information for decisions. In order to meet this demand for analytical talent, a Center for Business Intelligence and Analytics (CBIA housed within the university seeks to develop knowledge and skills vital in the fast changing field of business, through developing the next generation of managers and analysts with skills in decision-making through use of analytical techniques. This presentation provides the strategic framework for the definition and development of a CBIA and framework for joint academic and industry collaboration to develop the next generation of industry experts. The core components including industry demand, alliance objectives including objectives, curriculum and talent requirements, and opportunities.

FY 1999 report on the results of the technology development of super metal (R and D of the undersea oil production support system). Development of technology of aluminum-base high corrosion resistant fine structure controlling metal materials; 1999 nendo super metal no gijutsu kaihatsu seika hokokusho. Kaitei sekiyu seisan shien system kenkyu kaihatsu (aluminium kei kotaishokusei bisai kozo seigyo kinzoku zairyo gijutsu kaihtsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of developing aluminum materials excellent in industrial characteristics, a study was conducted to create large-sized aluminum materials having mesoscopic crystal structure, and the FY 1999 results were summarized. In this fiscal year, to create the fine crystal grain structure, the following were conducted: fundamental study of high strain accumulation process, study of a mechanism of fine crystal grain formation, development of the processing method, and development of evaluation technology. In the study of high strain accumulation process, effects were examined of conditions of molten metal rolling on castability. Fundamental studies were also made of innovative technologies such as ECAP method, pre-forged structure controlling rolling, accumulative roll bonding and thermomechanical treatment. In the study of the mechanism of fine crystal grain structure formation, the following were conducted: Al-Mn base alloys produced by molten metal rolling, 6061 alloys by warm rolling with different peripheral speed rolling, and 7000 group alloys by warm rolling. As to the processing method, study was made on low-temperature rolling technology and rapid heat treatment technology. As to the evaluation technology, study was made on evaluation of crystal grain diameter by EBSP. (NEDO)

Composites comprising silicon carbide fibers dispersed in magnesia-aluminate matrix and fabrication thereof and of other composites by sinter forging

Science.gov (United States)

Panda, Prakash C.; Seydel, Edgar R.; Raj, Rishi

1989-10-03

A novel ceramic-ceramic composite of a uniform dispersion of silicon carbide fibers in a matrix of MgO.multidot.nAl.sub.2 O.sub.3 wherein n ranges from about 1 to about 4.5, said composite comprising by volume from 1 to 50% silicon carbide fibers and from 99 to 50% MgO.multidot.nAl.sub.2 O.sub.3. The composite is readily fabricated by forming a powder comprising a uniform dispersion of silicon carbide fibers in poorly crystalline phase comprising MgO and Al.sub.2 O.sub.3 in a mole ratio of n and either (a) hot pressing or preferably (b) cold pressing to form a preform and then forging utilizing a temperature in the range of 1100.degree. C. to 1900.degree. C. and a strain rate ranging from about 10.sup.-5 seconds .sup.-1 to about 1 seconds .sup.-1 so that surfaces cracks do not appear to obtain a shear deformation greater than 30%.

Consolidation effects on tensile properties of an elemental Al matrix composite

Energy Technology Data Exchange (ETDEWEB)

Tang, F. [Building 4515, MS 6064, Metals and Ceramics Division, Oak Ridge National Lab, Oak Ridge, TN 37831 (United States)]. E-mail: tangf@ornl.gov; Meeks, H. [Ceracon Inc., 5150 Fairoaks Blvd. 01-330, Carmichael, CA 95628 (United States); Spowart, J.E. [UES Incorporated, AFRL/MLLM Building 655, 2230 Tenth St. Suite 1, Wright-Patterson AFB, OH 45433 (United States); Gnaeupel-Herold, T. [NIST Center for Neutron Research, 100 Bureau Dr. Stop 8562, Gaithersburg, MD 20899-8562 (United States); Prask, H. [NIST Center for Neutron Research, 100 Bureau Dr. Stop 8562, Gaithersburg, MD 20899-8562 (United States); Anderson, I.E. [Materials and Engineering Physics Program, Ames Laboratory, Iowa State University, Ames, IA 50011 (United States)

2004-11-25

In a simplified composite design, an unalloyed Al matrix was reinforced by spherical Al-Cu-Fe alloy particles (30 vol.%), using either commercial purity (99.7%) or high purity (99.99%) fine powders (diameter < 10 {mu}m). This composite material was consolidated by either vacuum hot pressing (VHP) or quasi-isostatic forging. The spatial distribution of reinforcement particles in both VHP and forged samples was shown to be almost the same by quantitative characterization with a multi-scale area fraction analysis technique. The tensile properties of all composite samples were tested and the forged materials showed significantly higher strength, while the elastic modulus values of all composite materials were close to the upper bound of theoretical predictions. Neutron diffraction measurements showed that there were high compressive residual stresses in the Al matrix of the forged samples and relatively low Al matrix residual stresses (predominantly compressive) in the VHP samples. By tensile tests and neutron diffraction measurements of the forged samples after annealing, it was shown that the high compressive residual stresses in the Al matrix were relieved and that tensile strength was also reduced to almost the same level as that of the VHP samples. Therefore, it was deduced that increased compressive residual stresses and enhanced dislocation densities in the forged composites raised the tensile strength to higher values than those of the VHP composites.

A novel tool to predict youth who will show recommended usage of diabetes technologies

DEFF Research Database (Denmark)

Neylon, Orla M.; Skinner, Timothy C.; O'Connell, Michele A.

2016-01-01

Controversy exists regarding which individuals will benefit most from commencement of diabetes technologies such as continuous subcutaneous insulin infusion (CSII) or continuous glucose monitoring systems (CGMS), such as 'real-time' sensor-augmented pumping (SAP). Because higher usage correlates ...