WorldWideScience

Sample records for hot forging tools

  1. Improving durability of hot forging tools by applying hybrid layers

    Directory of Open Access Journals (Sweden)

    Z. Gronostajski

    2015-10-01

    Full Text Available This paper deals with problems relating to the durability of the dies used for the hot forging of spur gears. The results of industrial tests carried out on dies with a hybrid layer (a nitrided layer (PN + physical vapor deposition (PVD coating applied to improve their durability are presented. Two types of hybrid layers, differing in their PVD coating, were evaluated with regard to their durability improvement effectiveness. The tests have shown that by applying hybrid layers of the nitrided layer/PVD coating type one can effectively increase the durability of hot forging tools.

  2. 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.

  3. FEA Based Tool Life Quantity Estimation of Hot Forging Dies Under Cyclic Thermo-Mechanical Loads

    Science.gov (United States)

    Behrens, B.-A.; Bouguecha, A.; Schäfer, F.; Hadifi, T.

    2011-01-01

    Hot forging dies are exposed during service to a combination of cyclic thermo-mechanical, tribological and chemical loads. Besides abrasive and adhesive wear on the die surface, fatigue crack initiation with subsequent fracture is one of the most frequent causes of failure. In order to extend the tool life, the finite element analysis (FEA) may serve as a means for process design and process optimisation. So far the FEA based estimation of the production cycles until initial cracking is limited as tool material behaviour due to repeated loading is not captured with the required accuracy. Material models which are able to account for cyclic effects are not verified for the fatigue life predictions of forging dies. Furthermore fatigue properties from strain controlled fatigue tests of relevant hot work steels are to date not available to allow for a close-to-reality fatigue life prediction. Two industrial forging processes, where clear fatigue crack initiation has been observed are considered for a fatigue analysis. For this purpose the relevant tool components are modelled with elasto-plastic material behaviour. The predicted sites, where crack initiation occurs, agree with the ones observed on the real die component.

  4. Laboratory and Performance Studies of Anti-wear Coatings Deposited on Nitrided Surfaces of Tools used in an Industrial Hot Die Forging Process

    Science.gov (United States)

    Hawryluk, Marek; Widomski, Paweł; Smolik, Jerzy; Kaszuba, Marcin; Ziemba, Jacek; Gronostajski, Zbigniew

    2017-04-01

    The paper presents the results of laboratory studies performed on produced anti-wear coatings as well as the results of performance tests conducted on tools with these coatings in industrial conditions, in the process of hot die forging. Three different coatings were selected: AlCrTiSiN, Cr/CrN and AlCrTiN, deposited by means of the vacuum-arc method on test samples as well as forging tools used in the hot forging process of a lid. The first part of the paper discusses the results of the studies performed in laboratory conditions, which included: surface morphology by means of SEM, hardness and Young modulus measurements, determination of the chemical composition by means of the EDS method, adhesion tests by means of the scratch method and tribological tests by means of the ball-on-disk method. The obtained results were correlated and applied in the analysis of the performance tests on forging punches with these coatings at an early stage of their performance (up to 4000 produced forgings), which were tested on 19 tools, of which 3 representatives were selected for each coating. A thorough analysis was performed of the wear phenomena and mechanisms and the manner of wear of hybrid layers as well as their resistance to the particular destructive mechanisms. Based on the performed laboratory and performance studies as well as their analysis, it was possible to select the optimal hybrid layer, which enables an increase in the durability of forging tools used in industrial hot die forging processes. The preliminary results showed that the best results for the whole working surface of the tool were obtained for the Cr/CrN layer, which characterizes in high adhesion as well as a lower Young modulus and hardness. In the case of high pressures and the correlated friction, better results were obtained for the AlCrTiN coating, which, besides its good adhesion properties, also exhibited the highest frictional resistance.

  5. Computer system for identification of tool wear model in hot forging

    Directory of Open Access Journals (Sweden)

    Wilkus Marek

    2016-01-01

    Full Text Available The aim of the research was to create a methodology that will enable effective and reliable prediction of the tool wear. The idea of the hybrid model, which accounts for various mechanisms of tool material deterioration, is proposed in the paper. The mechanisms, which were considered, include abrasive wear, adhesive wear, thermal fatigue, mechanical fatigue, oxidation and plastic deformation. Individual models of various complexity were used for separate phenomena and strategy of combination of these models in one hybrid system was developed to account for the synergy of various mechanisms. The complex hybrid model was built on the basis of these individual models for various wear mechanisms. The individual models expanded from phenomenological ones for abrasive wear to multi-scale methods for modelling micro cracks initiation and propagation utilizing virtual representations of granular microstructures. The latter have been intensively developed recently and they form potentially a powerful tool that allows modelling of thermal and mechanical fatigue, accounting explicitly for the tool material microstructure.

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

    OpenAIRE

    Legutko, S.; Meller, A.; Gajek, M.

    2013-01-01

    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 ...

  7. 轴承套圈锻造热切下料工装的改进%Improvement of Hot Shearing Blanking Tooling for Bearing Rings in Forging Process

    Institute of Scientific and Technical Information of China (English)

    刘辉; 赵玲权; 吴浩; 杨军

    2014-01-01

    分析传统套圈锻造热切下料工装使用中坯料容易产生毛刺、压塌变形、马蹄形、端面斜度大等缺陷的原因,改进下料工装模具和顶料杆,并进行了有限元模拟分析,通过改进前、后的使用对比得出了改进后下料工装的优越性。%The defects of blank such as burr,collapsing deformation,horseshoe and large end face slope are analyzed when hot shearing blanking tooling is used in traditional rings forging process.The blanking tooling die and lifter rod are improved,and the finite element simulation analysis is carried out.The superiority of improved blanking tooling is obtained by comparing the use before and after improvement.

  8. 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.

  9. Hot Forging of Nitrogen Alloyed Duplex Stainless Steels

    Institute of Scientific and Technical Information of China (English)

    P.Chandramohan; S.S. Mohamed Nazirudeen; S.S. Ramakrishnan

    2007-01-01

    Duplex stainless steels are gaining global importance because of the need for a high strength corrosion resistant material. Three compositions of this group were selected with three different nitrogen contents viz, 0.15 wt pct (alloy 1), 0.23 wt pct (alloy 2) and 0.32 wt pct (alloy 3). The steels were melted in a high frequency induction furnace and hot forged to various reductions from 16% to 62%. In this work, the effect of hot forging on the ferrite content, hardness, yield strength, impact strength and grain orientation (texture) were studied. Fracture analysis on all the forged specimens using SEM reveals that a size reduction of 48% results in maximum ductility and impact strength as well as minimal ferrite content and grain size. Thus the mechanical properties are found to have a direct correlation to ferrite content and grain size. The highest impact strength was observed in specimens with the smallest grain size, which was observed in specimens forged to 48% reduction in size.

  10. New low-carbon steel for hot, warm, or cold forging

    Energy Technology Data Exchange (ETDEWEB)

    Ollilainen, V.; Hocksell, E. [Imatra Steel Oy Ab, Imatra Steelworks (Finland)

    2000-05-01

    The development of a new high-strength steel started from the needs of cold forging and continued into hot- and warm-forging areas. The steel has a very low carbon content (<0.1% C) and chromium-boron alloying. Its hardening is simple: just water quenching without tempering. Hot forgings of this steel are directly quenched from forging temperature, resulting in process cost savings and weight reduction. (orig.)

  11. Environmentally Benign Lubricant Systems For Cold, Warm And Hot Forging

    DEFF Research Database (Denmark)

    Bay, Niels

    2010-01-01

    The growing awareness of environmental issues and the requirements to establish solutions diminishing the impact on working environment as well as external environment has initiated ever increasing efforts to develop new, environmentally benign tribological systems for metal forming. The present...... 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...

  12. 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...

  13. 76 FR 168 - Heavy Forged Hand Tools From China

    Science.gov (United States)

    2011-01-03

    ... following classes or kinds of heavy forged hand tools from China: (1) Axes and adzes, (2) bars and wedges... four Domestic Like Products: (1) Axes, adzes, and hewing tools, other than machetes, with or without... Industries: (1) Domestic producers of axes, adzes and hewing tools, other than machetes, with or...

  14. Hot Superplastic Powder Forging for Transparent nanocrystalline Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, W. Roger

    2006-05-22

    The program explored a completely new, economical method of manufacturing nanocrystalline ceramics, Hot Superplastic Powder Forging (HSPF). The goal of the work was the development of nanocrystalline/low porosity optically transparent zirconia/alumina. The high optical transparency should result from lack of grain boundary scattering since grains will be smaller than one tenth the wavelength of light and from elimination of porosity. An important technological potential for this process is manufacturing of envelopes for high-pressure sodium vapor lamps. The technique for fabricating monolithic nanocrystalline material does not begin with powder whose particle diameter is <100 nm as is commonly done. Instead it begins with powder whose particle diameter is on the order of 10-100 microns but contains nanocrystalline crystallites <<100 nm. Spherical particles are quenched from a melt and heat treated to achieve the desired microstructure. Under a moderate pressure within a die or a mold at temperatures of 1100C to 1300C densification is by plastic flow of superplastic particles. A nanocrystalline microstructure results, though some features are greater than 100nm. It was found, for instance, that in the fully dense Al2O3-ZrO2 eutectic specimens that a bicontinuous microstructure exists containing <100 nm ZrO2 particles in a matrix of Al2O3 grains extending over 1-2 microns. Crystallization, growth, phase development and creep during hot pressing and forging were studied for several compositions and so provided some details on development of polycrystalline microstructure from heating quenched ceramics.

  15. 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.

  16. 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.

  17. 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...

  18. Hot-forging Die Cavity Surface Layer Temperature Gradient Distribution and Determinant

    Institute of Scientific and Technical Information of China (English)

    WANG Huachang; WANG Guan; XIAO Han; WANG Hongfu

    2011-01-01

    Based on the car front-wheel-hub forging forming process of numerical simulation,the temperature gradient expression of forging model cavity near the surface layer was got ten,which illustrates that the forging temperature gradient is related to forging die materials thermal conductivity,specific heat and impact speed,and the correlation coefficient is 0.97.Under the different thermal conductivity,heat capacity and forging speed,the temperature gradient was compared with each other.The paper obtained the relevant laws,which illustrates the temperature gradient relates to these three parameters in a sequence of thermal conductivity > impact speed> specific heat capacity.To reduce thermal stress in the near-surface layer of hot forging cavity,the material with greater thermal conductivity coefficient and specific heat capacity should be used.

  19. Gear hot forging process robust design based on finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Xuewen, Chen [Henan University of Science and Technology, Luoyang (China); Won, Jung Dong [Jeju National University, Jeju (Korea, Republic of)

    2008-09-15

    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

  20. Simulative testing of friction in warm/hot forging

    DEFF Research Database (Denmark)

    Henningsen, Poul; Lindegren, Maria

    The objective of sub-task 3.2 is to determine the friction values for different work piece materials, tool materials and lubricants as a function of the main process parameters under conditions reflecting those which are present in typical warm/hot forming operations i.e. surface expansion, work...... piece and tool temperature. Based on this experimental work establish mathematical formulations of friction as a function of the basic parameters....

  1. 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.

  2. Investigation of influencing factors on friction during ring test in hot forging using FEM simulation

    Science.gov (United States)

    Sethy, Ritanjali; Galdos, Lander; Mendiguren, Joseba; Sáenz de Argandoña, Eneko

    2016-10-01

    Few studies have been undertaken to understand the friction in hot forming, especially when addressing the issue of varying input parameters. Better understanding of their role is therefore needed in order to obtain accurate results in numerical simulations. This paper numerically investigates the high temperature ring compression test to evaluate how frictional behaviour is affected by variations of input parameters (i.e. press velocity, Heat Transfer Coefficient (HTC), processing time, mesh size, material and tool temperature). The high temperature ring-compression process was simulated by means of Finite Element Modelling (FEM) using FORGE-3D software with the ring made of AISI 304L having ratio of outer diameter, inner diameter and height of 30:15:10. According to the results, the HTC and the press velocity have most significant effects on frictional behavior and the calibration curves needed to calculate the friction coefficients after experimental testing.

  3. The Development of a Ceramic Mold for Hot-Forging of Micro-Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Christenson, Todd; Garino, Terry

    1999-06-25

    A new mold material has been developed for use in making rare-earth permanent magnet components with precise dimensions in the 10 to 1000 µm range by hot-forging. These molds are made from molds poly(methyl)methacrylate (PMMA) made by deep x-ray lithography (DXRL). An alumina bonded with colloidal silica has been developed for use in these molds. This material can be heated to 950°C without changing dimensions where it develops the strength needed to withstand the hot-fmging conditions (750°C, 100 MPa). In addition, it disintegrates in HF so that parts can be easily removed after forging.

  4. Hot Cutting of Real-Time Cast-Forged GS Ductile Iron for Automotive Rods

    Science.gov (United States)

    Fouilland, Laurence; Mansori, Mohamed El

    2011-01-01

    In the global economy context, automotive industry suppliers have to keep a constant advance on products design and manufacturing process. Concerning automotive rods, the substitution of forged steel by spherical graphite iron (SG iron) with high mechanical properties constitutes a valid economic alternative. Such rods are produced using a complex coupled process: casting and forging followed by an austempered heat treatment. The forging operation is capable to shape the cast rod which introduces hot deformation to increase mechanical properties of net-shape SG iron rod. However, the intermediate re-heating between casting and forging must be avoided to keep competitive manufacturing costs. A major concern of this new process development is the cracks produced in rod's surface which are consecutive to hot spruing involved after casting operations. This issue is addressed in this paper which discusses the physical mechanisms involved in the hot ductile damage of SG iron. Hot cutting tests were performed to simulate the spruing operation which shows the close interactions between microstructure, machining parameters and resulting damages. The damage mechanisms in terms of crack initiation and its growth have been studied with respect to the constituent phases (austenite+graphite nodules), the cut surface morphology and the hot cutting performance.

  5. 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

    After solidification and cooling cast ingots contain voids due to improper feeding and volume shrinkage. Such voids are normally unwanted, so besides of forming the ingot to the desired shape, one of the purposes of the post processing of the ingot by hot forging is to close such voids by mechani......After solidification and cooling cast ingots contain voids due to improper feeding and volume shrinkage. Such voids are normally unwanted, so besides of forming the ingot to the desired shape, one of the purposes of the post processing of the ingot by hot forging is to close such 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....

  6. 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.

  7. MODELING OF MICROSTRUCTURAL EVOLUTION IN MICROALLOYED STEEL DURING HOT FORGING PROCESS

    Institute of Scientific and Technical Information of China (English)

    J. Wang; J. Chen; Z. Zhao; X.Y. Ruan

    2006-01-01

    The microstructural evolution of microalloyed steel during hot forging process was investigated using physical simulation experiments. The dynamic recrystallized fraction was described by modifying Avrami's equation, the parameters of which were determined by single hit compression tests. Double hit compression tests were performed to model the equation describing the static recrystallized fraction, and the obtained predicted values were in good agreement with the measured values. Austenitic grain growth was modeled as: Dinc5=D05 +1.6×1032t·exp(-716870/RT) using isothermal tests. Furthermore, an equation describing the dynamic recrystallized grain size was given as Ddyn=3771·Z-0.2.The models of microstructural evolution could be applied to the numerical simulation of hot forging.

  8. Determination and Analysis of Hardenability for Hot-Forging Die Steels with Deep-Hardening

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    ERH end-quenching method was us ed to determine the hardenability of four kinds hot-forging die steels with dee p-hardening and hence the order of their hardenability was given. The tempering hardness of the steels was measured and the tempering resistance was studied. It was approved that ERH method is effective for the determination of hardenability of deep-hardening steel and the beginning of hardness drop in the ERH specimen is caused by bainite occurring.

  9. DYNAMIC SIMULATION OF MICROSTRUCTURE EVOLUTION DURING HOT FORGING FOR ENGINE STIGMATA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Incorporated with constitutive relationship established by artificial neural networks (ANN), a coupled theroviscoplastic finite element procedure is developed for predicting the microstructure evolution in the hot forging process, considering the factors such as dynamic recrystallization, static recrystallization and grain growth etc. This software system is applied to predict the distributions of the grain size over the crosssection of stigmata, which is found to be in good agreement with the experimental results. The software can provide a fundament for optimizing technological parameters.

  10. Effect of Alloying Elements on Thermal Wear of Cast Hot-Forging Die Steels

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-qi; CHEN Kang-min; CUI Xiang-hong; JIANG Qi-chuan; HONG Bian

    2006-01-01

    The effect of main alloying elements on thermal wear of cast hot-forging die steels was studied. The wear mechanism was discussed. The results show that alloying elements have significant influences on the thermal wear of cast hot-forging die steels. The wear rates decrease with an increase in chromium content from 3% to 4% and molybdenum content from 2% to 3%, respectively. With further increase of chromium and molybdenum contents, chromium slightly reduces the wear resistance and molybdenum severely deteriorates the wear resistance with high wear rate. Lower vanadium/carbon ratio (1.5-2.5) leads to a lower wear resistance with higher wear rate. With an increase in vanadium/carbon ratio, the wear resistance of the cast steel substantially increases. When vanadium/carbon ratio is 3, the wear rate reaches the lowest value. The predominant mechanism of thermal wear of cast hot-forging die steels are oxidation wear and fatigue delamination. The Fe2O3 and Fe3O4 or lumps of brittle wear debris are formed on the wear surface.

  11. Effect of Hot Forging on Microstructural Evolution and Impact Toughness in Ultra-high Carbon Low Alloy Steel

    Science.gov (United States)

    Kim, J. B.; Kim, J. H.; Kang, C. Y.

    2016-12-01

    The effect of a hot forging ratio on the microstructural variation and tensile properties of ultra-high carbon low alloy steel was investigated. Scanning electron microscopic analyses depict that with an increase in the hot forging ratio, the thickness of the network and acicular proeutectoid cementite decreased. Moreover, the lamella spacing and thickness of the eutectoid cementite decreased and broke up into particle shapes, which then became spheroidized as the hot forging ratio increased. Furthermore, when the forging ratio exceeded 65%, the network and acicular shape of the as-cast state disappeared. By increasing the hot forging ratio, the tensile strength and elongation remained below 50%, but they increased rapidly with an increase in the forging ratio. Strength and elongation were not affected by the thickness of the proeutectoid and eutectoid cementites, but were greatly affected by the shape of the proeutectoid cementite. Due to the decrease in the austenite grain size, as well as the spheroidization of the cementite, the tensile strength and elongation sharply increased.

  12. Laser-dispersing of forging tools using AlN-ceramics

    Science.gov (United States)

    Noelke, C.; Luecke, M.; Kaierle, S.; Wesling, V.; Overmeyer, L.

    2014-02-01

    Forging tools for aluminum work pieces show an increased adhesive wear due to cold welding during the forging process. Laser dispersing offers at this point a great potential to fabricate protective layers or tracks with tailored properties that reduce abrasive or adhesive wear at the surface of highly stressed components. Using different process strategies, four metal ceramic compounds applied on two substrate geometries were investigated regarding their structural and mechanical properties and their performance level. The subsequent forging tests have pointed out a positive effect and less adhesive residuals on the laser dispersed tool surface.

  13. The development and production of thermo-mechanically forged tool steel spur gears

    Science.gov (United States)

    Bamberger, E. N.

    1973-01-01

    A development program to establish the feasibility and applicability of high energy rate forging procedures to tool steel spur gears was performed. Included in the study were relatively standard forging procedures as well as a thermo-mechanical process termed ausforming. The subject gear configuration utilized was essentially a standard spur gear having 28 teeth, a pitch diameter of 3.5 inches and a diametral pitch of 8. Initially it had been planned to use a high contact ratio gear design, however, a comprehensive evaluation indicated that severe forging problems would be encountered as a result of the extremely small teeth required by this type of design. The forging studies were successful in achieving gear blanks having integrally formed teeth using both standard and thermo-mechanical forging procedures.

  14. Analysis Of Potentiometric Methods Used For Crack Detection In Forging Tools

    Science.gov (United States)

    Pilc, Jozef; Drbúl, Mário; Stančeková, Dana; Varga, Daniel; Martinček, Juraj; Kuždák, Viktor

    2015-12-01

    Increased use of forging tools in mass production causes their increased wear and creates pressure to design more efficient renovation process. Renovation is complicated because of the identification of cracks expanding from the surface to the core material. Given that the production of forging tools is expensive, caused by the cost of tool steels and the thermo-chemical treatment, it is important to design forging tool with its easy renovation in mind. It is important to choose the right renovation technology, which will be able to restore the instrument to its original state while maintaining financial rentability. Choosing the right technology is difficult because of nitrided and heat-treated surface for high hardness and wear resistance. Article discusses the use of non-destructive method of detecting cracks taking into account the size of the cracks formed during working process.

  15. 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.

  16. Advanced numerical models for the thermo-mechanical-metallurgical analysis in hot forging processes

    Science.gov (United States)

    Ducato, Antonino; Fratini, Livan; Micari, Fabrizio

    2013-05-01

    In the paper a literature review of the numerical modeling of thermo-mechanical-metallurgical evolutions of a metal in hot forging operations is presented. In particular models of multiaxial loading tests are considered for carbon steels. The collected examples from literature regard phases transformations, also martensitic transformations, morphologies evolutions and transformation plasticity phenomena. The purpose of the tests is to show the correlation between the mechanical and the metallurgical behavior of a carbon steel during a combination of several types of loads. In particular a few mechanical tests with heat treatment are analyzed. Furthermore, Ti-6Al-4V titanium alloy is considered. Such material is a multi-phasic alloy, at room temperature made of two main different phases, namely Alpha and Beta, which evolve during both cooling and heating stages. Several numerical applications, conducted using a commercial implicit lagrangian FEM code are presented too. This code can conduct tri-coupled thermo-mechanical-metallurgical simulations of forming processes. The numerical model has been used to carry out a 3D simulation of a forging process of a complex shape part. The model is able to take into account the effects of all the phenomena resulting from the coupling of thermal, mechanical and metallurgical events. As simulation results strongly depend on the accuracy of input data, physical simulation experiments on real-material samples are carried out to characterize material behavior during phase transformation.

  17. Mechanism of Annealing Softening of Rolled or Forged Tool Steel

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In order to reduce hardness of rolled or forged steels after annealing and improve processability, the diameter and dispersity of carbides were measured by SEM and quantitative metallography. The microstructure of annealed steel was analyzed by TEM. The effects of the factors such as solute atoms, carbides, grain boundary and interphase boundary were studied. The mechanism of annealing softening of steels was analyzed on the examples of steels H13, S5, S7, X45CrNiMo4, which are treated with new technology. The results showed that the softening of H13, S7, S5 is easier obtained by isothermal or slow cooling annealing from slightly below A1, but hardness of X45CrNiMo4 after annealing is reduced effectively by obtaining coarse lamellar pearlite. Economic results can be obtained from good processability.

  18. 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...

  19. Microstructural, mechanical, corrosion and cytotoxicity characterization of the hot forged FeMn30(wt.%) alloy.

    Science.gov (United States)

    Čapek, Jaroslav; Kubásek, Jiří; Vojtěch, Dalibor; Jablonská, Eva; Lipov, Jan; Ruml, Tomáš

    2016-01-01

    An interest in biodegradable metallic materials has been increasing in the last two decades. Besides magnesium based materials, iron-manganese alloys have been considered as possible candidates for fabrication of biodegradable stents and orthopedic implants. In this study, we prepared a hot forged FeMn30 (wt.%) alloy and investigated its microstructural, mechanical and corrosion characteristics as well as cytotoxicity towards mouse L 929 fibroblasts. The obtained results were compared with those of iron. The FeMn30 alloy was composed of antiferromagnetic γ-austenite and ε-martensite phases and possessed better mechanical properties than iron and even that of 316 L steel. The potentiodynamic measurements in simulated body fluids showed that alloying with manganese lowered the free corrosion potential and enhanced the corrosion rate, compared to iron. On the other hand, the corrosion rate of FeMn30 obtained by a semi-static immersion test was significantly lower than that of iron, most likely due to a higher degree of alkalization in sample surrounding. The presence of manganese in the alloy slightly enhanced toxicity towards the L 929 cells; however, the toxicity did not exceed the allowed limit and FeMn30 alloy fulfilled the requirements of the ISO 10993-5 standard.

  20. Influence of the milling strategy on the durability of forging tools

    OpenAIRE

    Ficko, Mirko; Balič, Jože; Gotlih, Karl; Pahole, Ivo; Studenčnik, Dejan

    2015-01-01

    The quality of a tool's surface has a direct influence on the number of well-produced parts. For the machining of an active tool surface, two technological processes are used: electrical discharge machining and high-speed milling. These two processes are used when machining new tools and for the repairing of used forging tools. In both cases, the material has already been thermally treated, so it has to be used for hard milling. Practical experience shows that the milling strategy has a big i...

  1. Insensitivity on tensile properties of forged Mg-13Li-X alloy to hot-rolling deformation

    Institute of Scientific and Technical Information of China (English)

    LI Li; LI Huan-xi; ZHOU Tie-tao; CHEN Chang-qi; WU Qiu-lin; ZHANG Qing-quan; FU Zu-ming

    2006-01-01

    In order to examine the dependences of tensile properties of a forged Mg-13Li-X alloy on hot-rolling deformation and the underlying mechanisms tensile tests, residual stress measurements and texture analyses were conducted in the present study. It is found that after a hot-rolling deformation of 50% at 200 ℃, no much changes in tensile properties, nature and magnitude of residual stresses, and texture type and intensity can be identified for the alloy investigated. The insensitivity of tensile properties of the Mg-Li-X alloy to hot-rolling deformation is attributed at least partially to the insensitivity of residual stress and texture to hot-rolling.

  2. 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.

    2017-02-01

    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.

  3. Influence of Hot forging on Tribological behavior of Al6061-TiB2 In-situ composites

    Science.gov (United States)

    Pradeep kumar, G. S.; Keshavamurthy, R.; kuppahalli, Prabhakar; kumari, Prachi

    2016-09-01

    Al6061-TiB2 metal matrix composite was fabricated by stir casting technique via in-situ reaction, using mixture of Al6061 alloy, Potassium tetraflouroborate salt (KBF4) and tetraflourotitanate (K2TiF6). The cast composites were processed to hot forging, SEM studies; X- ray Diffraction studies (XRD), Microhardness and Dry friction and wear tests. Pin on disc type machine was used to perform tribological tests over a load range of 20-100N and sliding velocities of 0.314-1.57m/s. SEM and XRD studies confirms formation of fine in-situ TiB2 particles. Composites exhibit higher Microhardness, improved wear resistance and Lower COF with formation of TiB2 particles when compared with the unreinforced alloy. Compared to cast alloy and its Composites, forged alloy and its composites show superior Tribological behavior under similar test conditions.

  4. Waste Heat Recovery by Heat Pipe Air-Preheater to Energy Thrift from the Furnace in a Hot Forging Process

    Directory of Open Access Journals (Sweden)

    Lerchai Yodrak

    2010-01-01

    Full Text Available Problem statement: Currently, the heat pipe air-preheater has become importance equipment for energy recovery from industrial waste heat because of its low investment cost and high thermal conductivity. Approach: This purpose of the study was to design, construct and test the waste heat recovery by heat pipe air-preheater from the furnace in a hot brass forging process. The mathematical model was developed to predict heat transfer rate and applied to compute the heat pipe air-preheater in a hot brass forging process. The heat pipe air-preheater was designed, constructed and tested under medium temperature operating conditions with inlet hot gas ranging between 370-420°C using water as the working fluid with 50% filling by volume of evaporator length. Results: The experiment findings indicated that when the hot gas temperature increased, the heat transfer rate also increased. If the internal diameter increased, the heat transfer rate increased and when the tube arrangement changed from inline to staggered arrangement, the heat transfer rate increased. Conclusion/Recommendations: The heat pipe air-preheater can reduced the quantity of using gas in the furnace and achieve energy thrift effectively.

  5. Application Strategy in NC Machining Hot Forging Die for Handpiece Based on CAXA Makes Engineer%CAXA制造工程师在机头热锻模具NC加工中的应用策略

    Institute of Scientific and Technical Information of China (English)

    李海涛

    2012-01-01

    使用“CAXA制造工程师”完成机头热锻件的造型设计.在设计过程中合理使用缩放、型腔、分模工具生成机头热锻模具,使用软件的NC加工功能生成加工刀具轨迹.通过加工参数和刀具轨迹可以对机头热锻件模具型腔进行CAM的编程加工,最终把加工工艺清单和G代码传送到车间.车间在加工之前还可以通过CAXA制造工程师中的校核G代码功能,试一下加工代码的轨迹形状.%The modelling of the hot forging for handpiece was designed by " CAXA manufacturing engineer ". In the design process, hot forging die was reasonably generated by using scaling, cavity and parting tool. Tool pathes were generated by using the software with NC processing function. Through the processing parameters and tool path,hot forging die cavity could be machined by CAM programming processing. Finally, the process list and G code were transmited to the workshop. Before machining, through check G code function of CAXA manufacturing engineer, the shape of the trajectory of machining code could be tested.

  6. Simulations and Experiments of Hot Forging Design and Evaluation of the Aircraft Landing Gear Barrel Al Alloy Structure

    Science.gov (United States)

    Ram Prabhu, T.

    2016-04-01

    In the present study, the hot forging design of a typical landing gear barrel was evolved using finite element simulations and validated with experiments. A DEFORM3D software was used to evolve the forging steps to obtain the sound quality part free of defects with minimum press force requirements. The hot forging trial of a barrel structure was carried out in a 30 MN hydraulic press based on the simulation outputs. The tensile properties of the part were evaluated by taking samples from all three orientations (longitudinal, long transverse, short transverse). The hardness and microstructure of the part were also investigated. To study the soundness of the product, fluorescent penetrant inspection and ultrasonic testing were performed in order to identify any potential surface or internal defects in the part. From experiments, it was found that the part was formed successfully without any forging defects such as under filling, laps, or folds that validated the effectiveness of the process simulation. The tensile properties of the part were well above the specification limit (>10%) and the properties variation with respect to the orientation was less than 2.5%. The part has qualified the surface defects level of Mil Std 1907 Grade C and the internal defects level of AMS 2630 Class A (2 mm FBh). The microstructure shows mean grain length and width of 167 and 66 µm in the longitudinal direction. However, microstructure results revealed that the coarse grain structure was observed on the flat surface near the lug region due to the dead zone formation. An innovative and simple method of milling the surface layer after each pressing operation was applied to solve the problem of the surface coarse grain structure.

  7. Surface fatigue and failure characteristics of hot forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    Science.gov (United States)

    Townsend, D. P.

    1986-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground SISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  8. Surface fatigue and failure characteristics of hot-forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    Science.gov (United States)

    Townsend, Dennis P.

    1987-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground AISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  9. Three-dimensional Numerical Simulation and Experimental Analysis of Austenite Grain Growth Behavior in Hot Forging Processes of 300M Steel Large Components

    Institute of Scientific and Technical Information of China (English)

    Jiao LUO; Ying-gang LIU; Miao-quan LI

    2016-01-01

    The microstructure models were integrated into finite element (FE)code,and a three-dimensional (3D) FE analysis on the entire hot forging processes of 300M steel large components was performed to predict the distri-butions of effective strain,temperature field and austenite grain size.The simulated results show that the finest grains distribute in the maximum effective strain region because large strain induces the occurrence of dynamic re-crystallization.However,coarse macro-grains appear in the minimum effective strain region.Then,300M steel forg-ing test was performed to validate the results of FE simulation,and microstructure observations and quantitative analysis were implemented.The average relative difference between the calculated and experimental austenite grain size is 7.5 6%,implying that the present microstructure models are reasonable and can be used to analyze the hot forging processes of 300M steel.

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

    Directory of Open Access Journals (Sweden)

    Yoshimitsu Okazaki

    2012-08-01

    Full Text Available 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.

  11. Sprayformed Hot Work Steels for Rapid Tooling

    Institute of Scientific and Technical Information of China (English)

    Yunfeng Yang; Simo-Pekka Hannula

    2003-01-01

    The present work compares microstructures of hot work steels made by different processes, that is, by sprayforming,by casting, and a commercially supplied H13 steel. Material benefits are recognized by sprayforming hot working tools such as die inserts fo

  12. A Physically Based Dynamic Recrystallization Model Considering Orientation Effects for a Nitrogen Alloyed Ultralow Carbon Stainless Steel during Hot Forging

    Institute of Scientific and Technical Information of China (English)

    Gan-lin XIE; An HE; Hai-long ZHANG; Gen-qi WANG; Xi-tao WANG

    2016-01-01

    The nitrogen alloyed ultralow carbon stainless steel is a good candidate material for primary loop pipes of AP1000 nuclear power plant.These pipes are manufactured by hot forging,during which dynamic recrystallization acts as the most important microstructural evolution mechanism.A physically based model was proposed to describe and predict the microstructural evolution in the hot forging process of those pipes.In this model,the coupled effects of dislocation density change,dynamic recovery,dynamic recrystallization and grain orientation function were con-sidered.Besides,physically based simulation experiments were conducted on a Gleeble-3500 thermo-mechanical sim-ulator,and the specimens after deformation were observed by optical metallography (OM)and electron back-scat-tered diffraction (EBSD)method.The results confirm that dynamic recrystallization is easy to occur with increasing deformation temperature or strain rate.The grains become much finer after full dynamic recrystallization.The model shows a good agreement with experimental results obtained by OM and EBSD in terms of stress-strain curves,grain size,and recrystallization kinetics.Besides,this model obtains an acceptable accuracy and a wide applying scope for engineering calculation.

  13. Defining a method of evaluating die life performance by using finite element models (FEM) and a practical open die hot forging method

    Science.gov (United States)

    Marashi, J.; Foster, J.; Zante, R.

    2016-10-01

    Die wear, which is defined as a surface damage or removal of material from one or both of two solid surfaces in a sliding, rolling or impact motion relative to one another, is considered the main cause of tool failure. Wear is responsible for 70% of tool failure and a potential source of high costs; as much as 30% per forging unit in the forging industries [1]. This paper presents a unique wear prediction and measurement method for open die forging using a modified Archard equation, 3D FE simulation (to represent the actual forging process precisely) and an industrial scale forging trial. The proposed tool and experimental design is aimed at facilitating a cost effective method of tool wear analysis and to establish a repeatable method of measurement. It creates a platform to test different type of lubricants and coatings on industrial scale environment. The forging trial was carried out using 2100T Schuler Screw press. A full factorial experiment design was used on 3D simulation to identify the process setting for creating a measurable amount of tool wear. Wear prediction of 28.5 µm based on the simulation correlated with both Infinite Focus Optical Microscope and Coordinate Measuring Machine (CMM) measurement results of the practical trial. Thermal camera reading showed temperature raise on the area with maximum wear, which suggests that increase in contact time, causes thermal softening on tool steel. The measurement showed that abrasive wear and adhesive wear are dominant failure modes on the tool under these process conditions.

  14. Effect of Homogenization &Quenching Media on the Mechanical Properties of Sintered Hot Forged AISI 9250 P/MSteel Preforms

    Directory of Open Access Journals (Sweden)

    S. Aamani

    2014-10-01

    Full Text Available Present investigation is an attempt to generate experimental data in order to establish the influence of homogenization and cooling media on the mechanical properties of hot forged AISI 9250 sintered P/M steel to square cross-section bars produced using elemental powders. The elemental powders corresponding to final AISI 9250 composition ofFe-0.5%C-0.75%Mn-2.0%Si were taken in an appropriate proportion and blended in a pot mill for a period of 32 hours while maintaining the powder to ball ratio by weight as 1.1:1. Compacts of 28mm diameter and 36mm height were prepared on a 1.0 MN capacity Universal Testing Machine (UTM and using suitable die, punch and bottom insert assembly in the density range of 85±1 percent of theoretical by applying the pressure in the range of 550±10 MPa and by taking pre-weighed powder blend. In all 36 compacts were prepared. These green compacts were coated using the indigenously developed ceramic coating and the same was allowed to dry under the ambient conditions for a period of 14-16 hours. These ceramic coated compacts were re-coated 90° to the previous coating and re-dried under the aforementioned conditions for the same length of time. Ceramic coated compacts were sintered in an electric muffle furnace at 1120±10°C for a period of 120 minutes and subsequently hot forged to square cross-section bars of approximate dimensions of 14mm X 14mm X 95-100mm on a friction screw press of 1.00MN capacity at the sintering temperature itself. Nine forged specimens were oil quenched and remaining 27 forged bars were homogenized at the sintering temperature for a period of 60 minutes followed by quenching nine of them in oil, nine specimens in air and remaining nine were cooled in the furnace itself. Standard tensile specimens were prepared from each set and tested for evaluation of mechanical properties followed by SEM Fractography on the fractured specimen surfaces. Tensile tests results have established that the

  15. Forging tool shape optimization using pseudo inverse approach and adaptive incremental approach

    Science.gov (United States)

    Halouani, A.; Meng, F. J.; Li, Y. M.; Labergère, C.; Abbès, B.; Lafon, P.; Guo, Y. Q.

    2013-05-01

    This paper presents a simplified finite element method called "Pseudo Inverse Approach" (PIA) for tool shape design and optimization in multi-step cold forging processes. The approach is based on the knowledge of the final part shape. Some intermediate configurations are introduced and corrected by using a free surface method to consider the deformation paths without contact treatment. A robust direct algorithm of plasticity is implemented by using the equivalent stress notion and tensile curve. Numerical tests have shown that the PIA is very fast compared to the incremental approach. The PIA is used in an optimization procedure to automatically design the shapes of the preform tools. Our objective is to find the optimal preforms which minimize the equivalent plastic strain and punch force. The preform shapes are defined by B-Spline curves. A simulated annealing algorithm is adopted for the optimization procedure. The forging results obtained by the PIA are compared to those obtained by the incremental approach to show the efficiency and accuracy of the PIA.

  16. Optimization of hot working parameters of as-forged Nitinol 60 shape memory alloy using processing maps

    Science.gov (United States)

    Shu, Xiaoyong; Lu, Shiqiang; Wang, Kelu; Li, Guifa

    2015-07-01

    The hot deformation behavior of as-forged Nitinol 60 alloy (60 wt% Ni, 40 wt% Ti) was studied over the ranges of temperature, 650-850 °C, and strain rate, 0.01-1 s-1, using isothermal constant strain rate compression tests in a Gleeble-3500 simulator. The processing maps, based on the dynamic materials model, were developed to optimize the hot working parameters. The results show that the deformation parameters have a marked effect on the power dissipation efficiency and the instability parameter. A single unstable region (650-775 °C, 0.037-1 s-1), associated with flow localization and/or adiabatic shear, is detected from the processing map. This should be avoided in hot working process. The optimized hot working conditions correspond to 680-790 °C, 0.01-0.025 s-1 with peak efficiency of 0.45 at 720 °C, 0.01 s-1, and 820-850 °C, 0.1-1 s-1 with peak efficiency of 0.5 at 850 °C, 1 s-1. Microstructure observations indicate that the main deformation mechanism of optimized domains involves dynamic recrystallization.

  17. 汽车发电机爪极闭式热锻一步成形工艺研究%Study on single stage hot closed-die forging process of automobile alternator poles

    Institute of Scientific and Technical Information of China (English)

    杨程; 赵升吨; 章建军

    2011-01-01

    In order to get alternator poles forgings with less cutting work, based on the analysis of traditional forming technology and the structure of alternator poles, a single stage closed die hot forging process and forming tool-set of al ternator poles were put forward. A 3-D coupled thermo-mechanical finite element model was created, which was ana lyzed by the software Deform3D. The billet deformation, metal flow and forming load were obtained. The results show that the single closed die hot forging process of alternator poles is practicable.%为了得到少无切削的爪极锻件,在对爪极零件传统成形工艺和零件结构分析的基础上,提出了爪极闭式热锻一步成形工艺及对应的模具.建立了关于该成形工艺的三维热力耦合有限元分析模型,并通过Deform-3D对其进行了热模拟,得到了变形过程的坯料变形、材料流动情况和载荷行程曲线,结果证明了爪极闭式热锻一步成形的可行性.

  18. 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.

  19. Friction and Adhesion in Dry Warm Forging of Magnesium Alloy with Coated Tools

    Science.gov (United States)

    Matsumoto, Ryo; Kawashima, Hiroaki; Osakada, Kozo

    In order to develop forging process of magnesium alloys without lubrication, frictional behavior of magnesium alloy AZ31B (Mg-3%Al-1%Zn) is evaluated by a tapered plug penetration test under dry condition. The cemented tungsten carbide (WC) plugs polished to be a mirror-like surface are coated with diamond-like carbon (DLC) and TiAlN by physical vapor deposition (PVD). The cylindrical hollow billets of AZ31B are penetrated by the tapered plugs at a temperature of 200°C. The surface roughness of the hole of the billet, the adhesion length of AZ31B on the plug surface and the penetration load are measured. Compared with WC and TiAlN coating, it is found that DLC coating is effective in preventing AZ31B from adhering to the tool surface and reducing the penetration load.

  20. Heat Transfer Characteristics of Billet/Die Interface and Measures to Relieve Thermal Stress for Hot Forging Die

    Science.gov (United States)

    Lu, Baoshan; Wang, Leigang; Geng, Zhe; Huang, Yao

    2017-07-01

    The interfacial heat transfer coefficient (IHTC) shows the heat transfer capacity at the billet/die interface during the hot forming process, which affects the temperature gradient in the die that may potentially induce high thermal stress. Consequently, this determines the service life of the die. In this paper, a set of experimental equipments were used to identify the IHTC and the upsetting test of superalloy Inconel718 (GH4169) was carried out on the hot flat die to evaluate the IHTC characteristics after the billet heating and die preheating temperature, holding time, and billet deformation rate. The results indicated that the billet heating temperature has a minimal role in IHTC but the other components have a great impact on IHTC. Among them, the billet deformation rate has influenced the IHTC the most. In the die preheating temperature ranging from 150°C to 400°C, it was found that the preheating temperature was proportional to IHTC. A high preheating temperature that leads to a high IHTC was found unfavorable in relieving the die surface thermal stress, and also weakened the die hardness and strength. The IHTC declined with the increase in the holding time as a result of the billet oxidation. Based on these findings, the composite ceramic and polymetallic heat-resistant coatings on the die surface were prepared, respectively, to relieve the thermal stress of die surface by reducing IHTC. It showed that both of the treated dies could effectively reduce the IHTC, blocking the transferred heat from the hot billet and making it applicable to the different hot forging events.

  1. 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)).

  2. Production Process and Experimental Investigation of Hot Precision Forging of Hollow Cylindrical Gears%空心圆柱齿轮热精锻生产工艺及实验研究

    Institute of Scientific and Technical Information of China (English)

    左斌; 王宝雨; 李智; 郑明男

    2015-01-01

    齿轮制造是一个连续化生产过程,精密锻造生产齿轮既要保证生产连续、高效,又要保证模具的可靠。文中针对空心圆柱齿轮,提出了带心轴、无心轴-空心坯和无心轴-实心坯3种精密锻造模具方案,预测了3种方案精锻齿轮的成形载荷,通过有限元仿真分析了3种方案的齿轮成形过程、金属流动规律、模具受力状况和成形载荷,并设计了相应的生产工艺流程,比较了3种精密锻造方案和传统切削齿形加工的生产效率和材料利用率。通过齿轮热精锻实验验证了有限元仿真和载荷计算的准确性,确定无心轴-实心坯为行星齿轮热精锻生产的最佳工艺方案。%As gear manu facturing is a continuous production process,not only the continuity and efficiency of manu-facturing but also the reliability of forging tools should be guaranteed in the process of precision forging for manufac-turing gears.In this paper,firstly,three tool design schemes respectively with mandrel,without mandrel-hollow billet and without mandrel-solid billet were proposed for the precision forging of hollow cylindrical gears,and the corresponding forming loads were predicted.Secondly,tooth formation,metal flow,tool stress and forming load were analyzed via finite element simulation.Then,the procedures corresponding to the three schemes were de-signed,and a comparison was made between these three precision forging processes and the conventional cutting process in terms of production efficiency and material utilization.Finally,forging trials for hollow cylindrical gears were conducted to verify the validity of finite element simulation and forming load calculation,and the manufactur-ing process without mandrel-solid billet was proved to be the best for the hot precision forging of gears.

  3. Manufacturing of Precision Forgings by Radial Forging

    Science.gov (United States)

    Wallner, S.; Harrer, O.; Buchmayr, B.; Hofer, F.

    2011-01-01

    Radial forging is a multi purpose incremental forging process using four tools on the same plane. It is widely used for the forming of tool steels, super alloys as well as titanium- and refractory metals. The range of application goes from reducing the diameters of shafts, tubes, stepped shafts and axels, as well as for creating internal profiles for tubes in Near-Net-Shape and Net-Shape quality. Based on actual development of a weight optimized transmission input shaft, the specific features of radial forging technology is demonstrated. Also a Finite Element Model for the simulation of the process is shown which leads to reduced pre-processing effort and reduced computing time compared to other published simulation methods for radial forging. The finite element model can be applied to quantify the effects of different forging strategies.

  4. Influence of Processing Parameters on Grain Size Evolution of a Forged Superalloy

    Science.gov (United States)

    Reyes, L. A.; Páramo, P.; Salas Zamarripa, A.; de la Garza, M.; Guerrero-Mata, M. P.

    2016-01-01

    The microstructure evolution of nickel-based superalloys has a great influence on the mechanical behavior during service conditions. Microstructure modification and the effect of process variables such as forging temperature, die-speed, and tool heating were evaluated after hot die forging of a heat-resistant nickel-based alloy. Forging sequences in a temperature range from 1253 to 1323 K were considered through experimental trials. An Avrami model was applied using finite element data to evaluate the average grain size and recrystallization at different evolution zones. It was observed that sequential forging at final temperatures below 1273 K provided greater grain refinement through time-dependent recrystallization phenomena. This investigation was aim to explore the influence of forging parameters on grain size evolution in order to design a fully homogenous and refined microstructure after hot die forging.

  5. Structure Analysis of 168 MN Hot Die Forging Press%168MN热模锻压力机的结构分析

    Institute of Scientific and Technical Information of China (English)

    郭改丽; 余朝辉

    2016-01-01

    The design features of prestressed frame structure , wedge structure , closed height adjustment structure and top ejector structure in 168 MN hot die forging press have been introduced in the paper .%介绍了168 MN热模锻压力机预应力机架结构、楔式结构、封闭高度调整结构、上顶料结构的设计特点。

  6. 轴承锻件整径工装改进%Improvement of repair diameter tooling for bearing forging

    Institute of Scientific and Technical Information of China (English)

    单晓伟; 常玉滨

    2016-01-01

    The repair diameter process for bearing forging outer ring and inner ring generally performed on different machines. For saving machines, one maching was used to repair diameter of bearing forging inner ring and outer ring, but wasting time and strength when replacement products. In view of the existing problems, the repair diameter tooling was improved to enhance production efifciency and machine utilization.%轴承锻件外圈和内圈整径工序一般在不同机床上进行。为节省机床,准备用一台机床对内、外圈整径,但换活时费时费力。针对存在的问题,改进了整径工装,提高了生产效率和机床利用率。

  7. 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

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Shao-Yi Hsia

    2015-09-01

    Full Text Available 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.

  10. 发动机泵体精密热模锻成形工艺研究%Precision Hot-die Forging Process of Engine Pump Body

    Institute of Scientific and Technical Information of China (English)

    郭巨寿; 于霞; 李爱平; 孙晓飞; 张宝荣; 任晓峰

    2014-01-01

    目的:为了提高发动机泵体综合机械性能和降低制造成本,采用精密热模锻技术来实现泵体的精确成形。方法通过确定锻件分模面位置,建立了泵体精密热模锻几何实体模型;在此基础上,建立了泵体热模锻过程三维有限元模型和模拟参数,实现了精密热模锻过程有限元模拟模型。结果通过数值模拟,获得了成形过程中坯料的速度场、等效应变场和温度场及载荷-行程曲线,揭示了泵体热模锻过程中金属充填模具型腔的情况及其变形机理,获得了温度场应变分布以及载荷、打击能量随行程的变化规律,优化了预成形时拍方坯料长度等参数,为确定成形工艺参数提供了科学依据。结论经试验验证,新工艺成形的锻件非加工外形面尺寸精度达到了零件要求,数值模拟结果与实验结果一致。%Objective In order to improve the mechanical properties and to decrease the production cost of engine pump body, precision hot forging process was employed to manufacture the part. Methods Based on the determination of parting face position of the part, the solid geometric model was established for the precision hot-die forging of pump body. A 3D fi-nite-element model and the simulation parameters for the forging process were built, and the finite element simulation mod-el for precision hot-die forging was achieved. Results The distributions of velocity field, equivalent Mises plastic strain field and temperature field, as well as the curves of load and blow energy with displacement were obtained through numeri-cal simulation. The results revealed the metal filling of the mold cavity during the hot-die forging process of the pump body and the deformation mechanism. The strain distribution of temperature field and the variation laws of the load and the blow energy with displacement were obtained. The process parameters during the preforming process such as the length of

  11. 离合器齿轮热精锻新工艺研究及模具设计%Study on Shaped Technology of Hot Precision Forging and Design of Die for Clutch Gears

    Institute of Scientific and Technical Information of China (English)

    于金伟

    2012-01-01

    针对离合器齿轮热精锻成形困难和不易脱模等难题,提出采用成形新工艺和最佳毛坯形状,使离合器齿轮精锻易于成形.设计了离合器齿轮热精锻成形的实用模具,该模具采用强力脱模装置,使锻件在锻击结束瞬间可以立即脱离凸模,解决了锻件将凸模抱死的关键技术问题.%Aiming at problems of difficulty in shaped technology of hot precision forging for clutch gears and hard pulling off of dies, a new process of hot precision forging and best roughcast shape for the clutch gears were put forward. A practical die was designed for hot precision forging the clutch gears. A powerful die separator was used to break forging piece away from male die as soon as the hammering was over. The key technical problem that the hot forging piece sticks to the male die is solved.

  12. Influence of minimum quantity lubrication parameters on tool wear and surface roughness in milling of forged steel

    Science.gov (United States)

    Yan, Lutao; Yuan, Songmei; Liu, Qiang

    2012-05-01

    The minimum quantity of lubrication (MQL) technique is becoming increasingly more popular due to the safety of environment. Moreover, MQL technique not only leads to economical benefits by way of saving lubricant costs but also presents better machinability. However, the effect of MQL parameters on machining is still not clear, which needs to be overcome. In this paper, the effect of different modes of lubrication, i.e., conventional way using flushing, dry cutting and using the minimum quantity lubrication (MQL) technique on the machinability in end milling of a forged steel (50CrMnMo), is investigated. The influence of MQL parameters on tool wear and surface roughness is also discussed. MQL parameters include nozzle direction in relation to feed direction, nozzle elevation angle, distance from the nozzle tip to the cutting zone, lubricant flow rate and air pressure. The investigation results show that MQL technique lowers the tool wear and surface roughness values compared with that of conventional flood cutting fluid supply and dry cutting conditions. Based on the investigations of chip morphology and color, MQL technique reduces the cutting temperature to some extent. The relative nozzle-feed position at 120°, the angle elevation of 60° and distance from nozzle tip to cutting zone at 20 mm provide the prolonged tool life and reduced surface roughness values. This fact is due to the oil mists can penetrate in the inner zones of the tool edges in a very efficient way. Improvement in tool life and surface finish could be achieved utilizing higher oil flow rate and higher compressed air pressure. Moreover, oil flow rate increased from 43.8 mL/h to 58.4 mL/h leads to a small decrease of flank wear, but it is not very significant. The results obtained in this paper can be used to determine optimal conditions for milling of forged steel under MQL conditions.

  13. Improvement Of Tools Durability By Application Of Hybrid Layer Of Nitrided/PECVD Coating.

    Directory of Open Access Journals (Sweden)

    Gronostajski Z.

    2015-09-01

    Full Text Available In the process of die hot forging the tools are subjected to three main factors leading to their destruction: the intensive thermal shocks, cyclically variable mechanical loads and intensive friction. The above mentioned factors causing destruction in the process of hot forging and warm forging concern mainly the surface of tools. Hybrid technique nitrided/PECVD belong to the latest methods of modifying the properties of the surface layer. In the paper the application of this technique for forging tools of constant velocity joint body is presented. The durability of the new tools is much better than the tools applied so far.

  14. 连杆无飞边锻造工艺及模具系统研究%Flashless Forging Process and Tool System of Connecting Rod

    Institute of Scientific and Technical Information of China (English)

    刘雅辉; 刘淑梅; 何文涛; 于秋华

    2014-01-01

    目的:研究连杆无飞边锻造工艺,以及闭模锻造过程中中间工序件的设计和所需的模具系统。方法通过建立有限元模型,分析连杆的预锻和终锻过程中金属流动长度、成形载荷和模具寿命,为模具设计提供数据支持。结果数值模拟结果表明金属充模效果良好;连杆大端主要在预锻中成形,而连杆小端和杆部主要在终锻中成形;预锻和终锻的最大成形载荷分别为437 t 和850 t;连杆大端的模腔圆角为模具失效危险区。结论通过辊锻制坯、预锻分配物料和终锻精密成形,实现了连杆的无飞边锻造。%Objective To investigate the flashless forging process connecting rod, as well as the design of intermediate goods and the die system needed for closed-die forging. Methods Finite element model was estimated to analyze the metal flowing path during pre and final forging, forming load and tool life, which provided data support for the tool design. Re-sults Results of numerical simulation showed that: the metal die-filling was desired; the big end of connecting rod was mainly formed in the pre-forging, whereas small end and stem were mainly formed in the final forging; the maximum form-ing loads of pre and final forging were 437 t and 850 t, respectively; the dangerous zone of tool failure occurred at the big end of connecting rod in the cavity. Conclusion Through rolling for blank preparation, pre-forging for materials distribu-tion and final forging for precision forming, flashless precision forging for connecting rod was achieved.

  15. Analysis Of Deformation And Microstructural Evolution In The Hot Forging Of The Ti-6Al-4V Alloy

    Directory of Open Access Journals (Sweden)

    Kukuryk M.

    2015-06-01

    Full Text Available The paper presents the analysis of the three-dimensional strain state for the cogging process of the Ti-6Al-4V alloy using the finite element method, assuming the rigid-plastic model of the deformed body. It reports the results of simulation studies on the metal flow pattern and thermal phenomena occurring in the hot cogging process conducted on three tool types. The computation results enable the determination of the distribution of effective strain, effective stress, mean stress and temperature within the volume of the blank. This solution has been complemented by adding the model of microstructure evolution during the cogging process. The numerical analysis was made using the DEFORM-3D consisting of a mechanical, a thermal and a microstructural parts. The comparison of the theoretical study and experimental test results indicates a potential for the developed model to be employed for predicting deformations and microstructure parameters.

  16. 热锻件常见缺陷及防止方法%Hot Forging Common Defects and Prevention Methods

    Institute of Scientific and Technical Information of China (English)

    曹伟; 孙福勋

    2012-01-01

    The forging quality affects directly the performance of parts and service life. The paper analyses the reason of the heating control of oxidation, improper may cause the decarburization, excessive heat or burn, internal crack, heating distributed defects, of forging process prone to filling discontent, and fold, crack defects ,points out the reasons and puts forward the concrete prevention and solutions, and has important guiding role of ensure product quality and control forgings.%锻件质量的优劣直接影响着零件的性能及使用寿命。本文对加热控制不当可能导致的氧化、脱碳、过热或过烧、内部裂纹、加热不均匀等缺陷,对锻造过程容易出现的充填不满、折叠、裂纹等缺陷进行了研究分析,指出了产生的原因,提出了具体的预防、解决方案,对保证和控制锻件产品质量具有重要的指导作用。

  17. Improvement Of Tools Durability By Application Of Hybrid Layer Of Nitrided/PECVD Coating.

    OpenAIRE

    Gronostajski Z.; Kaszuba M.; Paschke H.; Zakrzewski T.; Rogaliński G.

    2015-01-01

    In the process of die hot forging the tools are subjected to three main factors leading to their destruction: the intensive thermal shocks, cyclically variable mechanical loads and intensive friction. The above mentioned factors causing destruction in the process of hot forging and warm forging concern mainly the surface of tools. Hybrid technique nitrided/PECVD belong to the latest methods of modifying the properties of the surface layer. In the paper the application of this technique for fo...

  18. An Analysis Of The Industrial Forging Process Of Flange In Order To Reduce The Weight Of The Input Material

    Directory of Open Access Journals (Sweden)

    Gronostajski Z.

    2015-06-01

    Full Text Available This paper presents an analysis of the industrial process of hot forging a flange. The authors developed several thermomechanical models of the forging process for which they carried out computer simulations using the MSC.Marc 2013 software. In the Jawor Forge flanges with a neck are manufactured by hot forging in crank presses with a maximum load of 25 MN. The input material, in the form of a square bar, is heated up to a temperature of 1150°C and then formed in three operations: upsetting, preliminary die forging and finishing die forging. The main aim of the studies and the numerical analyses, in which the geometry of the tools would be modified, was to maximally reduce the amount of the input material taking into account the capabilities of the Jawor Forge, and consequently to significantly reduce the production costs. Besides the Forge’s equipment resources, the main constraint for modifications was the flange-with-neck forging standard which explicitely defines the tolerances for this element. The studies, which included numerical modelling, infrared measurements and technological tests, consisted in changing the geometry of the tools and that of the forging preform. As a result, the optimum direction for modifications aimed at reducing the mass of the input material was determined. The best of the solutions, making it possible to produce a correct forging in the Jawor Forge operating conditions, were adopted whereby the weight of the preform was reduced by 6.11%. Currently research is underway aimed at the application of the proposed and verified modifications to other flange forgings.

  19. Development of knowledge-based system for die forging process and tool design%基于知识的模锻工艺与模具设计系统开发

    Institute of Scientific and Technical Information of China (English)

    李世龙; 庄新村; 黄少东; 刘川林; 赵震; 陈军

    2012-01-01

    "Hot forging + machining" is an effective way to manufacture spiral bevel gear. The final product's performance depends on the quality of hot forging. The finite element software Deform-3D was used to simulate the hot forging process of spiral bevel driven gear blank. The metal flow law of forging process was studied. The results show that the stress and strain are great and the temperature is high in the ladder place because of the metal flows difficultly in the ladder place. The flow of metal can be better by improving die parameters. The relationship between initial forging temperature and forging energy consumption was studied. The results show that the forging energy consumption changes a little when the initial forging temperature is different The numerical simulation on forging technology can be applied to improve die patameters and forging process parameters.%模锻工艺与模具设计是一个经验积累和知识集成的过程.为实现优化设计的目标,利用知识工程的理论,综合开放性知识库、知识管理系统以及基于知识逻辑推理技术的支持,以Unigraphics NX为开发平台,采用混合开发模式,建立基于知识的模锻设计系统.从而有效地利用已有的知识和经验,提高设计过程的自动化程度和效率,扩展系统的应用范围与稳定性.

  20. Development and experiments of direct resistance heating in hot forging%电阻直接加热锻造成形工艺方法及试验

    Institute of Scientific and Technical Information of China (English)

    门正兴; 周杰; 王梦寒; 邵长伟

    2011-01-01

    A new hot-forging method by means of direct resistance heating is investigated aiming at the long produce time and large energy consumption of traditional hot forging.The hot upsetting experiments with cylindrical billet of 42CrMo4 are performed.The influences of initial contact force,surface quality of the billet and current intensity on the heating temperature are researched.The results of the experiments show that the billet can be heated quickly to forming temperature by the approach.The relatively low initial contact force is useful to increase the heating temperature.The heating temperature is proportional to the square of the current intensity,and the heating temperature is seriously affected by the surface quality.During the forming process the billet cooling rate is effectively decreased and the forming time is extended in relation to the resistance heating.%针对传统锻造工艺流程长,能源消耗大的缺点,提出了一种采用电阻直接加热技术的新型热锻成形系统。采用该系统对42CrMo4棒料进行了热镦粗实验,研究了预接触压力、工件表面质量、电流对工件加热及成形过程的影响,为电阻直接加热模锻成形提供了指导。试验结果表明:1)采用该方法可以在短时间内将工件在模具中加热到成形温度;2)小的初始接触压力有助于提高工件的加热温度;3)在初始接触压力不变情况下,工件的加热温度与电流强度的平方成正比;4)模具与工件接触面质量对加热温度有重要的影响;5)在成形过程中采用恒定电流强度的电阻加热有效地降低了工件的冷却速度,使成形时间延长30%。

  1. 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

    2017-01-01

    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. PMID:28925963

  2. Numerical modelling of the forging process of rolls for rolling mills

    OpenAIRE

    Charles, J F; Castagne, S.; Zhang, Lihong; Habraken, Anne; Cescotto, Serge

    2000-01-01

    This article presents comparisons of forging processes between two flat tools, between two round tools, and at different forging temperatures. Simulation results help to recover and better understa,d long practice in the forging industry. Peer reviewed

  3. Tool for Generating Realistic Residential Hot Water Event Schedules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hendron, B.; Burch, J.; Barker, G.

    2010-08-01

    The installed energy savings for advanced residential hot water systems can depend greatly on detailed occupant use patterns. Quantifying these patterns is essential for analyzing measures such as tankless water heaters, solar hot water systems with demand-side heat exchangers, distribution system improvements, and recirculation loops. This paper describes the development of an advanced spreadsheet tool that can generate a series of year-long hot water event schedules consistent with realistic probability distributions of start time, duration and flow rate variability, clustering, fixture assignment, vacation periods, and seasonality. This paper also presents the application of the hot water event schedules in the context of an integral-collector-storage solar water heating system in a moderate climate.

  4. Process Modeling In Cold Forging Considering The Process-Tool-Machine Interactions

    Science.gov (United States)

    Kroiss, Thomas; Engel, Ulf; Merklein, Marion

    2010-06-01

    In this paper, a methodic approach is presented for the determination and modeling of the axial deflection characteristic for the whole system of stroke-controlled press and tooling system. This is realized by a combination of experiment and FE simulation. The press characteristic is uniquely measured in experiment. The tooling system characteristic is determined in FE simulation to avoid experimental investigations on various tooling systems. The stiffnesses of press and tooling system are combined to a substitute stiffness that is integrated into the FE process simulation as a spring element. Non-linear initial effects of the press are modeled with a constant shift factor. The approach was applied to a full forward extrusion process on a press with C-frame. A comparison between experiments and results of the integrated FE simulation model showed a high accuracy of the FE model. The simulation model with integrated deflection characteristic represents the entire process behavior and can be used for the calculation of a mathematical process model based on variant simulations and response surfaces. In a subsequent optimization step, an adjusted process and tool design can be determined, that compensates the influence of the deflections on the workpiece dimensions leading to high workpiece accuracy. Using knowledge on the process behavior, the required number of variant simulations was reduced.

  5. Kinematics Performance and Structural Analysis for the Design of a Serial-parallel Manipulator Transferring a Billet for a Hot Extrusion Forging Process

    Directory of Open Access Journals (Sweden)

    Chu Anh My

    2015-12-01

    Full Text Available To reduce the downtime and optimize the use of energy and manpower, a serial-parallel manipulator is designed for transferring heavy billets for a hot extrusion forging station. With the purpose of increasing the structural rigidity and restricting the end-effector (a gripper so that it always moves in parallel with the ground surface, parallel links are added in between the serial links of the manipulator. This modification of the conventional structure must be considered in the modelling and analysis of the design. This paper addresses a methodology to investigate the kinematics performance and strength analysis of the designed robot. With respect to the parallel links, the constraint equation is derived and put together with the kinematical model. Based on the entire model that is formulated, the inverse kinematics, the transferring time, the reachable workspace, the degree of dexterity and the manipulability index are analysed and discussed to demonstrate its kinematical performance. In addition, to investigate the structural characteristics of the end-effector module, the static displacement and stress distributed on module's components are computed and simulated using the computer-aided finite element method (FEM. These research results are effective and useful in assessing and improving the robot’s design.

  6. Irradiation study on Sr{sub n+1}Ti{sub n}O{sub 3n+1} Ruddlesden-Popper phases synthesized by hot-forging

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ming; Fu, Engang [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fuierer, Paul; Dickens, Peter [Department of Materials and Metallurgical Engineering, New Mexico Institute of Mining and Technology, Socorro, NM 87801 (United States)

    2013-02-15

    The hot-forging technique was used to obtain both the n = 2 (Sr{sub 3}Ti{sub 2}O{sub 7}) and n = {infinity} (SrTiO{sub 3}) members of Ruddlesden-Popper phase Sr{sub n+1}Ti{sub n}O{sub 3n+1}. Pure phase and high density (>95% theoretical) materials were achieved using this technique. These polycrystalline samples were irradiated with 200 keV He ions to a fluence of 2 x 10{sup 21} ion/m{sup 2} (corresponding to a peak dose at 5 dpa) at room temperature to study radiation damage effects. Microstructural investigation on pristine and irradiated samples was performed using grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM). Three phenomena are revealed upon comparing prisXtine versus irradiated samples. First, both compounds interplanar lattice spacings increased after irradiation. Second, peak broadening possibly suggests incredibly small grain due to irradiation. Third, experiment results revealed an amorphization in the irradiated Sr{sub 3}Ti{sub 2}O{sub 7}, while no amorphization was observed in irradiated SrTiO{sub 3}. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. 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.

  8. The new forging process of a wheel hub drop forging

    Directory of Open Access Journals (Sweden)

    A. Gontarz

    2006-08-01

    Full Text Available Purpose: The main purpose of the research was working out a new flashless forming process of wheel hubforging in three-slide forging press (TSFP. It was assumed that the new process would be more effective thanthe forging processes applied in typical forging machines.Design/methodology/approach: The designing of the new process was based on the simulation by finiteelement method with the assumption of 3D state of strain. Calculations were made mainly for the analysis of thematerial flow kinematics and the process loads parameters. Experimental research were also made determiningthe dependency of clamping load in the function of forming load. On the basis of the analysis, the formingprocess of a wheel hub drop forging on the TSFP was worked out.Findings: The results of research confirmed the possibility of flashless forming process of wheel hub forgingin TSFP with axial cavities. The main parameters limiting the forming processes of wheel hub forgings are:permissible upsetting ratio and reciprocal relation of forming and clamping forces.Research limitations/implications: The further research within the range of determining force parameters fordifferent types of material and schemata of forming in TSFP were considered as purposeful. The works dealingwith analysis of forming processes of different types of products in order to classify drop forgings possible toform in this press will be examined.Practical implications: The comparison of the new forming process with the forging process on hammershowed majority of advantages which include: decrease of time and energy, decrease of drop forging weight andmachining, decrease of material consumption.Originality/value: The new process of wheel hub forging forming with axial cavities was worked out. Theparameters important during designing of forming processes in TSFP were provided. The relations betweenforces of forming tools were also determined.

  9. Standard guide for hot cell specialized support equipment and tools

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 Intent: 1.1.1 This guide presents practices and guidelines for the design and implementation of equipment and tools to assist assembly, disassembly, alignment, fastening, maintenance, or general handling of equipment in a hot cell. Operating in a remote hot cell environment significantly increases the difficulty and time required to perform a task compared to completing a similar task directly by hand. Successful specialized support equipment and tools minimize the required effort, reduce risks, and increase operating efficiencies. 1.2 Applicability: 1.2.1 This guide may apply to the design of specialized support equipment and tools anywhere it is remotely operated, maintained, and viewed through shielding windows or by other remote viewing systems. 1.2.2 Consideration should be given to the need for specialized support equipment and tools early in the design process. 1.2.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conv...

  10. A LOW TEMPERATURE ALUMINIZING TREATMENT OF HOT WORK TOOL STEEL

    OpenAIRE

    Matijević, Božidar

    2013-01-01

    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to the X40CrMoV5-1 hot tool steel. The aluminizing temperature was from 550 °C to 620 °C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the alumini...

  11. A low temperature aluminizing treatment of hot work tool steel

    Energy Technology Data Exchange (ETDEWEB)

    Matijevic, B., E-mail: bozidar.matijevic@fsb.hr [University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Zagreb (Croatia)

    2010-07-01

    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to hot tool steel H13. The aluminizing treating temperature was from 550 to 620°C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the aluminized layer thickness and the oxide layer were studied. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), glow discharge optical spectroscopy (GDOS) were applied to observe the cross-sections and the distribution of elements. (author)

  12. 基于伪逆算法的冷镦坯模具的优化%Optimization of cold forging perform tools using Pseudo Inverse Approach

    Institute of Scientific and Technical Information of China (English)

    Ali HALOUANI; Yu-ming LI; Boussad ABBES; Ying-qiao GUO

    2012-01-01

    A new fast method called “Pseudo Inverse Approach” (PIA) for the multi-stage axi-symmetrical cold forging modelling is presented.The approach is based on the knowledge of the final part shape.Some intermediate configurations are introduced and corrected by using a free surface method to consider the deformation paths without contact treatment.A new direct algorithm of plasticity is developed using the notion of equivalent stress and the tensile curve,leading to a very efficient and robust plastic integration procedure.Numerical tests show that the Pseudo Inverse Approach is very fast compared with the incremental approach.The PIA is used in an optimization procedure for the preliminary preform tool design in multi-stage cold forging processes.This optimization problem aims to minimize the equivalent plastic strain and the punch force during the forging process.The preform tool shapes are represented by B-Spline curves.The vertical positions of the control points of B-Spline are taken as design variables.The evolution of the objective functions shows the importance of the tool preform shape optimization for the forging quality and energy saving.The forging results obtained by using the PIA are compared with those obtained by the classical incremental approaches to show the efficiency and accuracy of the PIA.%基于对最终产品形状的认识,提出一种新的快速的针对多工步轴对称冷锻建模方法一“伪逆法(PIA)”.为了考虑变形路径,引入了一些中间构型并且采用自由表面对这些中间构形进行修正而不采用接触算法.利用等效应力的概念和拉伸曲线,提出了一种新的快速而健壮的塑性积分直接算法.数值试验表明:与增量法相比,伪逆法速度非常快.PIA被用于多工步冷锻工艺预制体模具优化设计过程中,该优化过程以最大限度减少在锻造过程中产生的等效塑性应变和需要的冲压力为目标,预制体模具的形状采用B样条曲线描

  13. Die forging of the alloys Az80 and Zk60

    NARCIS (Netherlands)

    Kurz, G.; Clauw, B.; Sillekens, W.H.; Letzig, D.

    2009-01-01

    Overall goal of the MagForge project is to provide tailored and cost-effective technologies for the industrial manufacturing of magnesium forged components. Scientific and technological aspects are new alloys/feedstock materials with improved performance, forging process modeling and design tools wi

  14. Application of response surface methodology for determining cutting force model in turning hardened AISI H11 hot work tool steel

    Indian Academy of Sciences (India)

    B Fnides; M A Yallese; T Mabrouki; J-F Rigal

    2011-02-01

    This experimental study is conducted to determine statistical models of cutting forces in hard turning of AISI H11 hot work tool steel (∼ 50 HRC). This steel is free from tungsten on Cr–Mo–V basis, insensitive to temperature changes and having a high wear resistance. It is employed for the manufacture of highly stressed diecasting moulds and inserts with high tool life expectancy, plastic moulds subject to high stress, helicopter rotor blades and forging dies. The workpiece is machined by a mixed ceramic tool (insert CC650 of chemical composition 70%Al23+30%TiC) under dry conditions. Based on 33 full factorial design, a total of 27 tests were carried out. The range of each parameter is set at three different levels, namely low, medium and high. Mathematical models were deduced by software Minitab (multiple linear regression and response surface methodology) in order to express the influence degree of the main cutting variables such as cutting speed, feed rate and depth of cut on cutting force components. These models would be helpful in selecting cutting variables for optimization of hard cutting process. The results indicate that the depth of cut is the dominant factor affecting cutting force components. The feed rate influences tangential cutting force more than radial and axial forces. The cutting speed affects radial force more than tangential and axial forces.

  15. Cooling Systems Design in Hot Stamping Tools by a Thermal-Fluid-Mechanical Coupled Approach

    Directory of Open Access Journals (Sweden)

    Tao Lin

    2014-06-01

    Full Text Available Hot stamping tools with cooling systems are the key facilities for hot stamping process of Ultrahigh strength steels (UHSS in automotive industry. Hot stamping tools have significant influence on the final microstructure and properties of the hot stamped parts. In serials production, the tools should be rapidly cooled by cooling water. Hence, design of hot stamping tools with cooling systems is important not only for workpieces of good quality but also for the tools with good cooling performance and long life. In this paper, a new multifield simulation method was proposed for the design of hot stamping tools with cooling system. The deformation of the tools was also analyzed by this method. Based on MpCCI (Mesh-based parallel Code Coupling Interface, thermal-fluid simulation and thermal-fluid-mechanical coupled simulation were performed. Subsequently, the geometrical parameters of the cooling system are investigated for the design. The results show that, both the distance between the ducts and the distance between the ducts and the tools loaded contour have significant influence on the quenching effect. And better quenching effect can be achieved with the shorter distance from the tool surface and with smaller distance between ducts. It is also shown that, thermal expansion is the main reason for deformation of the hot forming tools, which causes the distortion of the cooling ducts, and the stress concentration at corner of the ducts.

  16. Craft improvement on moving cutting board of HBP-160 high-speed hot forging machine%HBP-160高速热镦机移动刀板的工艺改进

    Institute of Scientific and Technical Information of China (English)

    宋薇; 寇长江

    2012-01-01

      针对HBP-160高速热镦机原来使用的移动刀板焊接后缺陷多,反复补焊消耗过多人力物力的问题,更换刀板材料,省去焊接工序及相应加工成本,提高了加工效率%  The moving cutting board used in the HBP-160 high-speed hot forging machine before has many defects after welding, and over complementary welding would consume too much manpower and material resources. Aimed at the problems above, it needs to change the material of the cutting board, thus to save welding procedure and relevant processing cost and to improve processing effectiveness.

  17. Computer-Aided Design of Manufacturing Chain Based on Closed Die Forging for Hardly Deformable Cu-Based Alloys

    Science.gov (United States)

    Pietrzyk, Maciej; Kuziak, Roman; Pidvysots'kyy, Valeriy; Nowak, Jarosław; Węglarczyk, Stanisław; Drozdowski, Krzysztof

    2013-07-01

    Two copper-based alloys were considered, Cu-1 pct Cr and Cu-0.7 pct Cr-1 pct Si-2 pct Ni. The thermal, electrical, and mechanical properties of these alloys are given in the paper and compared to pure copper and steel. The role of aging and precipitation kinetics in hardening of the alloys is discussed based upon the developed model. Results of plastometric tests performed at various temperatures and various strain rates are presented. The effect of the initial microstructure on the flow stress was investigated. Rheologic models for the alloys were developed. A finite element (FE) model based on the Norton-Hoff visco-plastic flow rule was applied to the simulation of forging of the alloys. Analysis of the die wear for various processes of hot and cold forging is presented as well. A microstructure evolution model was implemented into the FE code, and the microstructure and mechanical properties of final products were predicted. Various variants of the manufacturing cycles were considered. These include different preheating schedules, hot forging, cold forging, and aging. All variants were simulated using the FE method and loads, die filling, tool wear, and mechanical properties of products were predicted. Three variants giving the best combination of forging parameters were selected and industrial trials were performed. The best manufacturing technology for the copper-based alloys is proposed.

  18. 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....

  19. Enhancement of Aluminum Alloy Forgings through Rapid Billet Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kervick, R.; Blue, C. A.; Kadolkar, P. B.; Ando, T.; Lu, H.; Nakazawa, K.; Mayer, H.; Mochnal, G.

    2006-06-01

    Forging is a manufacturing process in which metal is pressed, pounded or squeezed under great pressure and, often, under high strain rates into high-strength parts known as forgings. The process is typically performed hot by preheating the metal to a desired temperature before it is worked. The forging process can create parts that are stronger than those manufactured by any other metal working process. Forgings are almost always used where reliability and human safety are critical. Forgings are normally component parts contained inside assembled items such airplanes, automobiles, tractors, ships, oil drilling equipment, engines missiles, and all kinds of capital equipment Forgings are stronger than castings and surpass them in predictable strength properties, producing superior strength that is assured, part to part.

  20. 76 FR 24856 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Science.gov (United States)

    2011-05-03

    ..., and Picks & Mattocks) From the People's Republic of China: Final Results of the Expedited Sunset... & Adzes, Bars & Wedges, Hammers & Sledges, and Picks & Mattocks) from the People's Republic of China..., track tools and wedges; (3) picks and mattocks; and (4) axes, adzes and similar hewing tools. Hand...

  1. The Impact of a Mechanical Press on the Accuracy of Products and the Reliability of Tools in Cold Forging

    DEFF Research Database (Denmark)

    Krusic, V.; Arentoft, Mogens; Rodic, T.

    2005-01-01

    Cold extrusion is an economic production process for the production of elements of complex forms and accurate dimensions. The first part of the article is about the impact that mechanical press has on the accuracy of products and reliability of tools. There is a description of the mechanical press...... main characteristics and in addition, individual examples show the impact of these chracteristics on the accuracy of products. Further on, the impact of rigidity to the thickness of starter clutch barrel bottom, for rigid and softer press, is shown. The second part presents the tools and entire system...... the formed part, tools, press rigidity. There is also an analysis of the impact that scatter of the blank mass has at different press rigidities. An example of measuring dymanic rigidity of 1000-ton mechanical press during the process of starter barrel cold extrusion is shown....

  2. A Knowledge base model for complex forging die machining

    CERN Document Server

    Mawussi, Kwamiwi; 10.1016/j.cie.2011.02.016

    2011-01-01

    Recent evolutions on forging process induce more complex shape on forging die. These evolutions, combined with High Speed Machining (HSM) process of forging die lead to important increase in time for machining preparation. In this context, an original approach for generating machining process based on machining knowledge is proposed in this paper. The core of this approach is to decompose a CAD model of complex forging die in geometric features. Technological data and topological relations are aggregated to a geometric feature in order to create machining features. Technological data, such as material, surface roughness and form tolerance are defined during forging process and dies design. These data are used to choose cutting tools and machining strategies. Topological relations define relative positions between the surfaces of the die CAD model. After machining features identification cutting tools and machining strategies currently used in HSM of forging die, are associated to them in order to generate mac...

  3. 76 FR 52313 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Science.gov (United States)

    2011-08-22

    ..., and Picks & Mattocks) From the People's Republic of China: Continuation of Antidumping Duty Orders... & Adzes, Bars & Wedges, Hammers & Sledges, and Picks & Mattocks) (``Hand Tools'') from the People's... & Wedges, Hammers & Sledges, and Picks & Mattocks) From the People's Republic of China: Final Results...

  4. Dynamic Recrystallization Behavior of Microalloyed Forged Steel

    Institute of Scientific and Technical Information of China (English)

    WANG Jin; CHEN Jun; ZHAO Zhen; RUAN Xue-yu

    2008-01-01

    The dynamic recrystallization behavior of microalloyed forged steel was investigated with a compression test in the temperature range of 1 223--1 473 K and a strain rate of 0. 01--5 s-1. Activation energy was calculated to be 305. 9 kJ/mol by regression analysis. Modeling equations were developed to represent the dynamic reerystalliza-tion volume fraction and grain size. Parameters of the modeling equations were determined as a function of the Zener-Hollomon parameter. The developed modeling equation will be combined with finite element modeling to prediet microstructural change during the hot forging processing.

  5. Improvements in the process of boss bar upset forging into a horizontal forging machine with the aim of joint knuckle forging quality improvement

    Science.gov (United States)

    Pankratov, D. L.; Nizamov, R. S.; Kharisov, I. Zh

    2016-06-01

    A new technique for tapered composing transition shaping has been put forward in the process of upset forging with the use of an experimental tool. The results of the upset forging process with the use of a new composing transition has been computer simulated.

  6. 小型轴承锻件整径工装和模具的探讨%Discussion on tooling and die for finishing hole and outer of small-sized bearing forgings

    Institute of Scientific and Technical Information of China (English)

    佟娜; 刘世华

    2013-01-01

    Aiming at the big dispersion error, ellipticity and conicity of the forgings produced by traditional forging method, the tooling for finishing hole and outer circle shape and die is designed. By this new method, the dimensional accuracy and stock utilization is increased so as to meet the need of bearing market.%  针对传统锻造方法加工出的锻件尺寸散差、椭圆度、锥度大的情况,设计出整径工装及模具,提高了锻件尺寸精度和材料利用率,满足轴承市场需求。

  7. 热模锻传动轴滑动轴承承载力分析%Analysis on the Load Capacity of Slip Bearing for Cardan Shaft of Hot Die Forging Press

    Institute of Scientific and Technical Information of China (English)

    魏田华; 殷文齐; 杜建伟

    2015-01-01

    The essay introduces the Reynolds equation used to calculate the load capacity of oil film of slip bearing which is in dynamic pressure and radial type for the cardan shaft of the hot die forging press. The key dimension of the bearing is designed by Reynolds model. The finite element model is created based upon such dynamic pressure and radial slip bearing, the result of which analyse the pressure distribution on the oil film and variation of load capacity under different minimum oil film thickness. It concludes the maximum load capacity and the corresponding different minimum oil film thickness.%介绍用于动压径向滑动轴承油膜承载能力计算的雷诺方程。根据雷诺计算模型确定某热模锻压机传动轴滑动轴承的关键尺寸,并以该动压径向滑动轴承为基础,建立有限元模型,分析在不同最小油膜厚度下油膜上的压力分布和承载力变化,分析得出滑动轴承的最大承载能力及其所对应的最小油膜厚度。

  8. Study of hot hardness characteristics of tool steels

    Science.gov (United States)

    Chevalier, J. L.; Dietrich, M. W.; Zaretsky, E. V.

    1972-01-01

    Hardness measurements of tool steel materials in electric furnace at elevated temperatures and low oxygen environment are discussed. Development of equation to predict short term hardness as function of intial room temperature hardness of steel is reported. Types of steel involved in the process are identified.

  9. Precision Hot-die Forging Process of the Common-rail Pipe%车用发动机共轨管精密成形工艺与试验研究

    Institute of Scientific and Technical Information of China (English)

    张波; 郭巨寿; 袁宇亭; 曹艳; 于霞; 康凤

    2016-01-01

    目的:为了提高柴油发动机的综合机械性能和降低制造成本,采用精密成形技术来实现共轨管的制备。方法通过工艺分析,设计了锻件形状、分模方式、飞边槽形式以及模具主要结构,建立了共轨管精密成形的有限元模型,并初步进行了主体设备选型。结果通过有限元模拟,对设计的精密成形工艺进行了仿真,获得了成形过程中坯料的速度场、等效应变分布及行程-载荷曲线,揭示了共轨管成形过程中金属在型腔中的流动情况,以及成形载荷的变化情况。结论通过最终工艺试制,验证并确定了工艺方案,根据零件的自身特点,突破了传统以投影面最大处为分模面的工艺,为最终的生产试制提供了参考依据。共轨管锻件充型饱满,5个小凸台均充型完全,尺寸均满足产品的技术要求,对后续简化工艺、提升产品的性能都有较大的作用。%In order to improve the mechanical properties and decrease the production cost of the Common-rail Pipe, preci-sion hot forging process is employed to manufacture the part. Based on the processing analyses, shape of the forge, parting face, and mould structure were determined, and the solid model was established. With the FEM,the distributions of velocity field, equivalent Mises plastic strain and the curves of load-time were obtained. With engineer testing, the process scheme has been certified, and the Common-rail Pipe were full-filled, the measure could meet all of the product requirements. It can helpful to predigest posterior techniques and improve the mechanical properties.

  10. Laser grooving of surface cracks on hot work tool steel

    Directory of Open Access Journals (Sweden)

    D. Klobčar

    2011-10-01

    Full Text Available The paper presents the analysis of laser grooving of 1.2343 tool steel hardened to 46 HRC. The effect of laser power and grooving speed on groove shape (i.e. depth and width, the material removal rate and the purity of produced groove as a measure of groove quality was investigated and analyzed using response surface methodology. Optimal parameters of laser grooving were found, which enables pure grooves suitable for laser welding.

  11. Virtual method for the determination of an optimum thermal design of hot stamping tools

    Science.gov (United States)

    Weiß, W.; Koplenig, M.; Alb, M.; Graf, J.

    2016-11-01

    This work presents a new virtual method for the optimised thermal design of hot stamping tools. It provides optimal positions of the tool's tempering ducts with respect to the average working temperature and its homogeneous distribution on the surface of a tool. It consists of a specific procedure for hot stamping tool design and a software framework in order to interconnect three domains: (I) a parametrised CAD tool model, (II) a linear thermal solver using a fast boundary element method and (III) an optimisation algorithm. This enables the automated set-up, simulation and optimisation of a duct topology. The boundary conditions for the simulations are derived from a reduced model of the thermal loading of the tool. The virtual method proposed is demonstrated on simplified tool segment geometries. The results are transferred to complex tool designs used in industry. For a selected use case, the number of ducts could be reduced by 50% through the application of the proposed method. These results are validated virtually based on an existing design. Hence, the new virtual method contributes to a CAE-driven tool design and a more efficient tool manufacturing.

  12. Forging Collaborative Partnerships: The Waterloo Neighborhood Project.

    Science.gov (United States)

    Gruenewald, Anne

    The Forging Collaborative Partnerships Project in Waterloo, Iowa is a collaborative venture to assist voluntary agencies in developing tools and strategies to strengthen collaborative relationships among public and nonprofit child welfare agencies and other key stakeholders as they adopt a family-focused philosophy. This monograph details how the…

  13. Design tool for large solar hot water systems - Uniform optimization of components and economy

    NARCIS (Netherlands)

    Visser, H.

    1996-01-01

    In close collaboration with the parties concerned, i.e. both the sellers and investors, a design and optimization method for large solar hot water systems is being developed. In order to support investors in achieving the feasibility of such systems, the normalized method including software tool for

  14. The capsicum transcriptome DB: a "hot" tool for genomic research.

    Science.gov (United States)

    Góngora-Castillo, Elsa; Fajardo-Jaime, Rubén; Fernández-Cortes, Araceli; Jofre-Garfias, Alba E; Lozoya-Gloria, Edmundo; Martínez, Octavio; Ochoa-Alejo, Neftalí; Rivera-Bustamante, Rafael

    2012-01-01

    Chili pepper (Capsicum annuum) is an economically important crop with no available public genome sequence. We describe a genomic resource to facilitate Capsicum annuum research. A collection of Expressed Sequence Tags (ESTs) derived from five C. annuum organs (root, stem, leaf, flower and fruit) were sequenced using the Sanger method and multiple leaf transcriptomes were deeply sampled using with GS-pyrosequencing. A hybrid assembly of 1,324,516 raw reads yielded 32,314 high quality contigs as validated by coverage and identity analysis with existing pepper sequences. Overall, 75.5% of the contigs had significant sequence similarity to entries in nucleic acid and protein databases; 23% of the sequences have not been previously reported for C. annuum and expand sequence resources for this species. A MySQL database and a user-friendly Web interface were constructed with search-tools that permit queries of the ESTs including sequence, functional annotation, Gene Ontology classification, metabolic pathways, and assembly information. The Capsicum Transcriptome DB is free available from http://www.bioingenios.ira.cinvestav.mx:81/Joomla/

  15. Estimation of Thermal Contact Conductance between Blank and Tool Surface in Hot Stamping Process

    Science.gov (United States)

    Taha, Zahari; Hanafiah Shaharudin, M. A.

    2016-02-01

    In hot stamping, the determination of the thermal contact conductance values between the blank and tool surface during the process is crucial for the purpose of simulating the blank rapid cooling inside the tool using finite element analysis (FEA). The thermal contact conductance value represents the coefficient of the heat transfer at the surface of two solid bodies in contact and is known to be influenced greatly by the applied pressure. In order to estimate the value and its dependency on applied pressure, the process of hot stamping was replicated and simplified into a process of compression of heated flat blank in between the tool at different applied pressure. The temperature of the blank and tool surface were measured by means of thermocouples installed inside the tool. Based on the measured temperature, the thermal contact conductance between the surfaces was calculated using Newton's cooling law equation. The calculated value was then used to simulate the blank cooling inside the tool using FEA commercial software. This paper describes an experimental approach to estimate the thermal contact conductance between a blank made of Boron Steel (USIBOR 1500) and tool made of Tool Steel (STAVAX). Its dependency on applied pressure is also studied and the experimental results were then compared with FEA simulations.

  16. 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

    equations for flow stress in cold as well as hot forging, determination of interface conditions, i.e. friction and heat transfer in cold and hot forging. The developments are validated by physical and numerical modeling and finally verified by analysis of some complex industrial examples....

  17. Modeling of Closed-Die Forging for Estimating Forging Load

    Science.gov (United States)

    Sheth, Debashish; Das, Santanu; Chatterjee, Avik; Bhattacharya, Anirban

    2017-02-01

    Closed die forging is one common metal forming process used for making a range of products. Enough load is to exert on the billet for deforming the material. This forging load is dependent on work material property and frictional characteristics of the work material with the punch and die. Several researchers worked on estimation of forging load for specific products under different process variables. Experimental data on deformation resistance and friction were used to calculate the load. In this work, theoretical estimation of forging load is made to compare this value with that obtained through LS-DYNA model facilitating the finite element analysis. Theoretical work uses slab method to assess forging load for an axi-symmetric upsetting job made of lead. Theoretical forging load estimate shows slightly higher value than the experimental one; however, simulation shows quite close matching with experimental forging load, indicating possibility of wide use of this simulation software.

  18. A search for new hot subdwarf stars by means of Virtual Observatory tools II

    CERN Document Server

    Pérez-Fernández, Esther; Solano, Enrique; Oreiro, Raquel; Rodrigo, Carlos

    2016-01-01

    Recent massive sky surveys in different bandwidths are providing new opportunities to modern astronomy. The Virtual Observatory (VO) represents the adequate framework to handle the huge amount of information available and filter out data according to specific requirements. In this work, we applied a selection strategy to find new, uncatalogued hot subdwarfs making use of VO tools. We used large area catalogues (GALEX, SDSS, SuperCosmos, 2MASS) to retrieve photometric and astrometric information of stellar objects. To these objects, we applied colour and proper motion filters, together with an effective temperature cutoff, aimed at separating hot subdwarfs from other blue objects such as white dwarfs, cataclysmic variables or main sequence OB stars. As a result, we obtained 437 new, uncatalogued hot subdwarf candidates. Based on previous results, we expect our procedure to have an overall efficiency of at least 80 per cent. Visual inspection of the 68 candidates with SDSS spectrum showed that 65 can be classif...

  19. Comparison of the secondary hardness effect after tempering of the hot-work tool steels

    Directory of Open Access Journals (Sweden)

    J. Mazurkiewicz

    2007-10-01

    Full Text Available Purpose: of this paper was to examine of the secondary hardness effect after tempering of the developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 in relation to standard hot-work tool steel X40CrMoV5-1.Design/methodology/approach: The investigations steels were made using the specimens made from the experimental steel, for which the working 47CrMoW¬V¬TiCe¬Zr16-26-8 denotation was adopted, similar to the ones used in the ISO Standard on using the standard alloy hot-work tool steel X40CrMoV5-1. Both investigated steels were melted in a vacuum electric furnace. Specimens made from the investigated steels were heat treated with austenitizing in salt bath furnaces for 30 minutes in the temperature range of 970-1180°C with gradation of 30°C. Next, the specimens were tempered twice in the temperature range of 450-660°C for 2 hours.Findings: The secondary hardness effect after tempering from temperature of 540oC in the 47CrMoW¬V¬Ti¬CeZr16-26-8 steel and from temperature of 510°C for the X40CrMoV5-1 steel, which is caused by the carbides M4C3 and M7C3 in the 47CrMoWVTiCeZr16-26-8 steel and M7C3 in the X40CrMoV5-1 steel.Practical implications: The developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 can be used to the hot work small-size tools which requires higher strength properties at elevated temperatureOriginality/value: The obtained results show the influence of the chemical compositions on the secondary hardness effect after tempering in the hot-work tool steel. The secondary hardness effect after tempering determined structure and mechanical properties in the this kinds of steels group.

  20. A search for new hot subdwarfs stars by means of Virtual Observatory tools.

    Science.gov (United States)

    Solano, E.; Pérez-Fernández, E.; Ulla, A.; Oreiro, R.; Rodrigo, C.

    2017-03-01

    We present here a selection strategy to find new, uncatalogued hot subdwarfs making use of Virtual Observatory (VO) tools. We used large area catalogues (GALEX, SDSS, Super-Cosmos, 2MASS) to retrieve photometric and astrometric information of stellar objects. To these objects, we applied colour and proper motion filters, together with an effective temperature cut-off, aimed at separating hot subdwarfs from other blue objects such as white dwarfs, cataclysmic variables or main sequence OB stars. As a result, we obtained 437 new, uncatalogued hot subdwarf candidates, which represents an increase of 17% in the census of known hot subdwarfs. Visual inspection of the 68 candidates with SDSS specrum showed that 65 can be classified as hot subdwarfs: 5 sdOs, 25 sdOBs and 35 sdBs. This success rate above 95 per cent proves the robustness and efficiency of our methodology. Taking advantage of the VOSA capabilities, we built the Spectral Energy Distribution (SED) of our candidates. 45 per cent of the SEDs showed infrared excesses, a signature of their probable binary nature. The stellar companions of the binary systems so detected are expected to be late-type main sequence stars. A more detailed description of the methodology, the analysis and results can be found at Pérez-Fernández et al. (2016)

  1. Near-Net Forging Technology Demonstration Program

    Science.gov (United States)

    Hall, I. Keith

    1996-01-01

    'contour preforms'. All of the contour preforms on this first-of-a-kind effort were imperfect, and the ingot used to fabricate two of the preforms was of an earlier vintage. As lessons were learned throughout the program, the tooling and procedures evolved, and hence the preform quality. Two of the best contour preforms were near- net forged to produce a process pathfinder Y-ring adapter and a 'mechanical properties pathfinder' Y-ring adapter. At this point, Lockheed Martin Astronautics elected to procure additional 2195 aluminum-lithium ingot of the latest vintage, produce two additional preforms, and substitute them for older vintage material non-perfectly filled preforms already produced on this contract. The existing preforms could have been used to fulfill the requirements of the contract.

  2. Feasibility study of fusion bonding for carbon fabric reinforced Polyphenylene Sulphide by hot-tool welding

    OpenAIRE

    De Baere, Ives; Van Paepegem, Wim; Degrieck, Joris

    2012-01-01

    In recent years, there is a growing interest in joining techniques for thermoplastic composites as an alternative to adhesive bonding. In this article, a fusion bonding process called hot-tool welding is investigated for this purpose and the used material is a carbon fabric reinforced polyphenylene sulphide. The welds are first observed through a microscope, after which the quality is experimentally assessed using a short three-point bending setup. A comparison is made between the welded spec...

  3. Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

    Science.gov (United States)

    Raab, A. E.; Berger, E.; Freudenthaler, J.; Leomann, F.; Walch, C.

    2011-05-01

    Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry1,2,3. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago1. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesive and abrasive tool wear. First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test. All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.

  4. An Analysis Of The Industrial Forging Process Of Flange In Order To Reduce The Weight Of The Input Material

    OpenAIRE

    Gronostajski Z.; Hawryluk M.; Kaszuba M.; Misiun G.; Niechajowicz A.; Polak S.; Pawełczyk M.

    2015-01-01

    This paper presents an analysis of the industrial process of hot forging a flange. The authors developed several thermomechanical models of the forging process for which they carried out computer simulations using the MSC.Marc 2013 software. In the Jawor Forge flanges with a neck are manufactured by hot forging in crank presses with a maximum load of 25 MN. The input material, in the form of a square bar, is heated up to a temperature of 1150°C and then formed in three operations: upsetting, ...

  5. The new forging process of a wheel hub drop forging

    OpenAIRE

    A. Gontarz

    2006-01-01

    Purpose: The main purpose of the research was working out a new flashless forming process of wheel hubforging in three-slide forging press (TSFP). It was assumed that the new process would be more effective thanthe forging processes applied in typical forging machines.Design/methodology/approach: The designing of the new process was based on the simulation by finiteelement method with the assumption of 3D state of strain. Calculations were made mainly for the analysis of thematerial flow kine...

  6. 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.

  7. 大型厚壁封头热锻成形中降低成型载荷的策略%Strategy of Decreasing Forming Load in Hot Forging of Heavy Thick-wall Sealing Head

    Institute of Scientific and Technical Information of China (English)

    徐戊矫; 丁永峰; 邹明平; 王凯庆

    2011-01-01

    The forging process for the heavy thick-wall saling head is required to neet the severe condition,whereas the forging factories often face eith the insufficient forging capacity to execute the foring process. Based on the rigid-viscoplastic FEM platform DEFORM-3D, the upper anvil swaging foring process was simulatde to ana1yze the cause of the fold defer and much higher forming load. The configuration of the upper anvil was optimized in the shape of saddle,meanwhile, the reduction of per revolution was deternined as 100 mm and the rotary anglc of per reduction of the upper anvil was decided as 24°. The optimized process was numerically simulated The results show that the forming load to execute the forging process is decreased to available range and the fold is avoided in the finished forgings The research is very helpful to improve the feasibility of forging proccss and forming quality of heavy thick-wall sealing head.%大型厚壁封头严苛的使用性能要求其采用整体锻造方法生产,但锻造企业通常不具备足够的设备能力以满足封头整体锻造超高的力能需求.基于刚粘塑性有限元模拟平台DEFORM-3D,对大型厚壁封头上砧旋转锻造成形原有的工艺方案进行了模拟仿真,分析了产生折迭缺陷和锻造载荷超限的原因.优化上砧形状为马鞍型,并确定上砧的运动轨迹为单周压下量为100mm,每压下一次后上砧旋转角度为24°.对优化后的工艺方案进行仿真计算.结果表明,工艺优化有效地将所需的成形载荷降到了设备能力允许的范围之内,并使整体锻造的封头无折迭缺陷.研究结果对提高封头整体锻造的可行性及改善大型厚壁封头的成形质量具有重要的指导意义.

  8. The Effect of Corner Radii and Part Orientation on Stress Distribution of Cold Forging Die

    OpenAIRE

    Ahmad B.  Abdullah; Kam S. Ling; Zahurin Samad

    2008-01-01

    One of the most critical problems in cold forging is the huge stresses generated from the deformation of metal leads to die failure. The distribution of stresses mainly depends on geometry of the die. An approach to optimal design in cold forging die geometry and orientation are presented in this paper. The impression cold forging dies of the Universal joint was generated using three-dimensional CAD modeling software, SolidWorks. This CAD modeling software coupled with FEA tools, COSMOSWorks....

  9. 浅谈Pro/E在锻造钩尾框模具设计制造中的应用%Discussion about application of Pro/E in design and manufacture of forging tool for coupler yoke

    Institute of Scientific and Technical Information of China (English)

    王辉荣

    2012-01-01

    基于Pro/E的设计、制造模块,结合锻造钩尾框的生产过程,对其模具设计、制造、生产的一般过程作了阐述.可对利用Pro/E进行锻造模具的设计、制造提供借鉴,是提高模具设计、制造效率、降低成本、增强企业竞争力的有效工具.%On the basis of Pro/E design and manufacturing module as well as in combination with the production process of the forging coupler yoke, the general process of tool design, manufacture, and production has been described. The Pro/E has been adopted in the design of tool, which is the key part in improving tool design & manufacturing efficiency & enterprise competitive as well as reducing the cost.

  10. A search for new hot subdwarf stars by means of virtual observatory tools II

    Science.gov (United States)

    Pérez-Fernández, E.; Ulla, A.; Solano, E.; Oreiro, R.; Rodrigo, C.

    2016-04-01

    Recent massive sky surveys in different bandwidths are providing new opportunities to modern astronomy. The Virtual Observatory (VO) represents the adequate framework to handle the huge amount of information available and filter out data according to specific requirements. In this work, we applied a selection strategy to find new, uncatalogued hot subdwarfs making use of VO tools. We used large area catalogues like GALEX, Sloan Digital Sky Survey (SDSS), SuperCosmos and Two Micron All Sky Survey (2MASS) to retrieve photometric and astrometric information of stellar objects. To these objects, we applied colour and proper motion filters, together with an effective temperature cutoff, aimed at separating hot subdwarfs from other blue objects such as white dwarfs, cataclysmic variables or main-sequence OB stars. As a result, we obtained 437 new, uncatalogued hot subdwarf candidates. Based on previous results, we expect our procedure to have an overall efficiency of at least 80 per cent. Visual inspection of the 68 candidates with SDSS spectrum showed that 65 can be classified as hot subdwarfs: 5 sdOs, 25 sdOBs and 35 sdBs. This success rate above 95 per cent proves the robustness and efficiency of our methodology. The spectral energy distribution of 45 per cent of the subdwarf candidates showed infrared excesses, a signature of their probable binary nature. The stellar companions of the binary systems so detected are expected to be late-type main-sequence stars. A detailed determination of temperatures and spectral classification of the cool companions will be presented in a forthcoming work.

  11. Thermophysical Properties of a Hot-Work Tool-Steel with High Thermal Conductivity

    Science.gov (United States)

    Kaschnitz, E.; Hofer, P.; Funk, W.

    2013-05-01

    In the highly productive permanent mold-casting process, the released enthalpy of the solidifying metal has to be transported through the surrounding hot-work tool-steel to the cooling system. For that reason, the thermal conductivity is a key property of the employed tool-steel. Recently, a new type of steel (Rovalma HTCS 130) has been developed and superior thermal properties have been claimed. In this study, measurements of the thermal diffusivity, heat capacity, and thermal expansion as a function of temperature are described for this steel and results of the computed thermal conductivity are reported. There is quite a discrepancy between the specification of the steel supplier and the results of this study; however, an improvement of the thermal conductivity for this type of steel can be confirmed.

  12. Modelling of defects in ingot forging

    DEFF Research Database (Denmark)

    Christiansen, Peter

    experimentally by utilizing downscaled lead model ingots (billets) being compressed by a tool with different lower die angles. Centreline defects, occurring due to the ingot casting processes, are modelled by drilling holes through the centreline of the cast billets. The experiments showed a marked influence...... are in closer agreement with the general understanding of the ingot forging process. Therefore porous metal plasticity should not be used solely when evaluating the soundness of the final, forged ingot based on FEM simulations. Based on an analysis of forming fracture limit diagrams combined with uncoupled...... ductile damage criteria, it is found that the normalized Cockcroft & Latham criterion is most suited for modelling damage in bulk metal forming, if the forming fracture limit diagram can be described by a straight line having a slope of -1/2. A damage criterion independent of slope is presented. Often...

  13. Preparation and amendment of technical standard “Technical requirements for forgings of high-speed tool steel”%技术标准《高速工具钢锻件技术条件》的编制及解读

    Institute of Scientific and Technical Information of China (English)

    金颖

    2013-01-01

    With the rapid development of domestic forging technology,the quality of forging products is being continuously improved.Especially,the improvement of the quality of high-speed tool steel has made that more and more highperformance tool products should be guaranteed by specifying forging process and inspection standards.In order to meet the development of forging technology,it is necessary to make amendments and supplements to previous technical standards.Now absorbing and learning from the corresponding technical specifications,and considering the situation and development trend of forging technology of high-speed tool steel,the standard “Technical requirements for forgings of high-speed tool steel” was amended in the aspects of technical requirements,test methods,inspection rules,marking and quality certification documents and the standards of forgings carbide uniformity diagrams.%近年来国内锻造技术发展迅猛,锻造产品的质量在不断提高,特别是高速工具钢锻件质量的提升,使得越来越多的高性能刀具产品要求通过规范锻造工艺及检验标准来保证.为适应锻造技术的发展,有必要对以往的技术标准进行相应的修正与补充.现吸收、借鉴国内相应技术规范,并充分考虑高速工具钢锻造技术现状及发展趋势,从技术要求、检验方法、检查规则、标志及质量证明文件、锻件碳化物均匀度评级图标准等相应要素人手,对机械行业标准《高速工具钢锻件技术条件》进行编制修订.

  14. DARWIN-HC:? A Tool to Predict Hot Corrosion of Nickel-Based Turbine Disks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hot Corrosion of turbine engine components has been studied for many years. The underlying mechan-isms of Type I Hot Corrosion and Type II Hot Corrosion are...

  15. DARWIN-HC: A Tool to Predict Hot Corrosion of Nickel-Based Turbine Disks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hot Corrosion of turbine engine components has been studied for many years. The underlying mechan-isms of Type I Hot Corrosion and Type II Hot Corrosion are...

  16. Precision forging technologies for magnesium alloy bracket and wheel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Fundamental investigations on precision forging technology of magnesium alloys were studied. As-cast billet prestraining and a new concept of hollow billet were proposed in order to reduce the maximum forming load. A scheme of isothermal forming and the use of combined female dies were adopted, which can improve the die filling capacity and ensure the manufacture of high quality forgings. By means of the developed technique, AZ80 alloy wheel and AZ31 alloy bracket were produced successfully at suitable process parameters and applied in the automotive industries. The results show that the hot compression of AZ80 magnesium alloy has the peak flow stresses of pre-strained alloy with finer grain, which are lower by 20% than those of as-cast alloy under the same deformation conditions. The forming load is related to contact area and average positive stress on interface during forging process.

  17. Residual Stresses in 21-6-9 Stainless Steel Warm Forgings

    Energy Technology Data Exchange (ETDEWEB)

    Everhart, Wesley A.; Lee, Jordan D.; Broecker, Daniel J.; Bartow, John P.; McQueen, Jamie M.; Switzner, Nathan T.; Neidt, Tod M.; Sisneros, Thomas A.; Brown, Donald W.

    2012-11-14

    Forging residual stresses are detrimental to the production and performance of derived machined parts due to machining distortions, corrosion drivers and fatigue crack drivers. Residual strains in a 21-6-9 stainless steel warm High Energy Rate Forging (HERF) were measured via neutron diffraction. The finite element analysis (FEA) method was used to predict the residual stresses that occur during forging and water quenching. The experimentally measured residual strains were used to calibrate simulations of the three-dimensional residual stress state of the forging. ABAQUS simulation tools predicted residual strains that tend to match with experimental results when varying yield strength is considered.

  18. Forging; Heat Treating and Testing; Technically Oriented Industrial Materials and Process 1: 5898.05.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The course provides students with advanced and exploratory experience in the area of plastic deformation of metals and in the changing of the physical characteristics of metals by the controlled application and timed removal of heat. Course content includes goals, specific objectives, safety in forge work, forging tools and equipment, industrial…

  19. Soundness of spray formed disc shape tools of hot-work steels

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Hannula, S.P

    2004-10-10

    This paper presents metallurgical factors causing porosity in the spray formed die inserts and the corresponding solutions. High quality die inserts can be produced by spray forming if a good control of deposition parameters and the sprayed material is assured. Mechanism of the pore formation is discussed. Deoxidation of the melt at tapping for porosity reduction is found to be very difficult because it causes great variation in viscosity of the melt so that the process is difficult to control. Often the tundish nozzle is also blocked or frozen. Modification of the steel composition is found to be an effective method to improve the soundness of the deposition. Effects of different alloying elements on the soundness of the deposition are discussed. Especially influential on improving the soundness is the increased alloying of high temperature carbide-forming elements such as vanadium. A new series of hot-work steels is developed for spray forming high quality tools, which have not only improved soundness, but also longer lifetimes than the conventional hot-work steels.

  20. Microstructure Modeling of a Ni-Fe-Based Superalloy During the Rotary Forging Process

    Science.gov (United States)

    Loyda, A.; Hernández-Muñoz, G. M.; Reyes, L. A.; Zambrano-Robledo, P.

    2016-06-01

    The microstructure evolution of Ni-Fe superalloys has a great influence on the mechanical behavior during service conditions. The rotary forging process offers an alternative to conventional bulk forming processes where the parts can be rotary forged with a fraction of the force commonly needed by conventional forging techniques. In this investigation, a numerical modeling of microstructure evolution for design and optimization of the hot forging operations has been used to manufacture a heat-resistant nickel-based superalloy. An Avrami model was implemented into finite element commercial platform DEFORM 3D to evaluate the average grain size and recrystallization during the rotary forging process. The simulations were carried out considering three initial temperatures, 980, 1000, and 1050 °C, to obtain the microstructure behavior after rotary forging. The final average grain size of one case was validated by comparing with results of previous experimental work of disk forging operation. This investigation was aimed to explore the influence of the rotary forging process on microstructure evolution in order to obtain a homogenous and refined grain size in the final component.

  1. Constitutive Equation of Superalloy In718 in Hammer Forging Process

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A constitutive equation reflecting the flow behavior ofSuperalloy In718 during the counter-blow hammer forging process was developed in terms of the relationship of flow stress and hot-deformation parameters, such as strain, strain rate, and deformation temperature. A new simplified approach for the complex multi-pass stress-strain curves has been attempted. The simulation curves calculated by constitutive equation are consistent with the experimental data.

  2. High Throughput, High Precision Hot Testing Tool for HBLED Wafer Level Testing

    Energy Technology Data Exchange (ETDEWEB)

    Solarz, Richard [KLA-Tencor Corporation, Milpitas, CA (United States); McCord, Mark [KLA-Tencor Corporation, Milpitas, CA (United States)

    2015-12-31

    The Socrates research effort developed an in depth understanding and demonstrated in a prototype tool new precise methods for teh characterization of color characteristics and flux from individual LEDs for the production of uniform quality lighting. This effort was focused on improving the color quality and consistency of solid state lighting and potentially reducing characterization costs for all LED product types. The patented laser hot testing method was demonstrated to be far more accurate than all current state of the art color and flux characterization methods in use by the solid state lighting industry today. A seperately patented LED grouping method (statistical binning) was demonstrated to be a useful approach to improving utilization of entire lots of large color and flux distributions of manufactured LEDs for high quality color solid-state lighting. At the conclusion of the research in late 2015 the solid-state lighting industry was however generally satisfied with its existing production methods for high quality color products for the small segment of customers that demand it, albeit with added costs.

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

    CERN Document Server

    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.

  4. Experimental and Theoretical Investigations of Hot Isostatically Pressed-Produced Stainless Steel/High Alloy Tool Steel Compound Materials

    Science.gov (United States)

    Lindwall, Greta; Flyg, Jesper; Frisk, Karin; Sandberg, Odd

    2011-05-01

    Consolidation of tool steel powders and simultaneous joining to a stainless 316L steel are performed by hot isostatic pressing (HIP). Two tool steel grades are considered: a high vanadium alloyed carbon tool steel, and a high vanadium and chromium alloyed nitrogen tool steel. The boundary layer arising during diffusion bonding is in focus and, in particular, the diffusion of carbon and nitrogen over the joint. Measurements of the elemental concentration profiles and corrosion tests by the double loop-electrochemical potentiokinetic reactivation (DL-EPR) method are performed. Comparative calculations with the DICTRA software are performed and are found to be in agreement with the experimental results. It is found that the carbon tool steel grade has a more critical influence on the corrosion resistance of the stainless 316L steel in comparison to the nitrogen tool steel grade.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yao, B. [Advanced Materials Processing and Analysis Center, and Department of Mechanical, Materials, and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Simkin, B.; Majumdar, B. [Materials and Metallurgical Engineering Department, New Mexico Institute of Mining and Technology, Socorro, NM 87801 (United States); Smith, C.; Bergh, M. van den [DWA Aluminum Composites, Chatsworth, CA 91311 (United States); Cho, K. [Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, MD 21005 (United States); Sohn, Y.H., E-mail: Yongho.Sohn@ucf.edu [Advanced Materials Processing and Analysis Center, and Department of Mechanical, Materials, and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States)

    2012-02-28

    Highlights: Black-Right-Pointing-Pointer Grain growth of cryomilled nanocrystalline aluminum during hot forging. Black-Right-Pointing-Pointer Use of hollow cone dark field imaging technique in TEM for grain size measurement. Black-Right-Pointing-Pointer Grain growth model of strain, strain rate and temperature for forging optimization. - Abstract: Grain growth of nanocrystalline aluminum ({sup nc}Al) in trimodal Al metal-matrix-composites (MMCs) during hot forging was investigated. The {sup 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 {sup 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 {sup nc}Al phase in trimodal Al MMCs after hot forging was documented with respect to temperature ranging from 175 Degree-Sign C to 287 Degree-Sign C, true strain ranging from 0.4 to 1.35 and strain rate ranging from 0.1 to 0.5 s{sup -1}. Hollow cone dark field imaging technique was employed to provide statistically confident measurements of {sup 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 {sup 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.

  6. Initial billet and forging dies shape optimization: Application on an axisymetrical forging with a hammer

    Science.gov (United States)

    Meng, Fanjuan; Labergere, Carl; Lafon, Pascal

    2011-05-01

    In metal forming process, the forging die design is the most important step for products quality control. Reasonable dies shape can not only reduce raw material cost but also improving material flow and eliminating defects. The main objective of this paper is to obtain some optimal parameters of the initial billet and forging dies shape according to the simulation results of a two-step metal forming process (platting step and forging step). To develop this metal forming process optimization system several numerical tools are required: geometric modelling (CATIA V5™), FEM analysis (ABAQUS®), work-flow control and optimization computation (MODEFRONTIER®). This study is done in three stages: simulating the two-step metal forming process, building surrogate meta-models to relate response and variables and optimizing the process by using advanced optimization algorithms. In this paper, a two-step axisymmetric metal forming project was studied as an example. By using our simulation model, we get 581 correct real simulation results totally. According to all these real values, we build the surrogate meta-models and obtain Pareto points for a two-objective optimization process. The choice of a solution in all Pareto points will be done by the engineer who can choose his best values according to their criterions of project.

  7. Hot microswimmers

    Science.gov (United States)

    Kroy, Klaus; Chakraborty, Dipanjan; Cichos, Frank

    2016-11-01

    Hot microswimmers are self-propelled Brownian particles that exploit local heating for their directed self-thermophoretic motion. We provide a pedagogical overview of the key physical mechanisms underlying this promising new technology. It covers the hydrodynamics of swimming, thermophoresis and -osmosis, hot Brownian motion, force-free steering, and dedicated experimental and simulation tools to analyze hot Brownian swimmers.

  8. 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

  9. 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.

  10. Powder Metallurgy Forged Gear Development

    Science.gov (United States)

    1985-03-01

    Unclassified) 12. PERSONAL AUTHOR(S) D. H. Ro, B. L. Ferguson, S. Pillay, D. T. Ostberg 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Month...Method Water Atomized SelecCion -Initial Alloy Distribution Prealloyed -Particle Size Distribution -100 Mesh kForging Quality) Uxmtpaction -Lubricant Zinc

  11. Closed Die Hammer Forging of Inconel 718

    Directory of Open Access Journals (Sweden)

    S. Chenna Krishna

    2014-01-01

    Full Text Available A method for the production of Inconel 718 (IN-718 hemispherical domes by closed die hammer forging is proposed. Different combination of operations employed for production are as follows: (i preforging + final forging + air cooling, (ii preforging + final forging + controlled cooling, (iii direct forging + controlled cooling, and (iv direct forging + air cooling. Last three combinations yielded a crack free hemispherical dome. The forged hemispherical domes were solution annealed at 980°C for 1 h and air cooled. The grain size of the domes at all locations was finer than ASTM No 4. Mechanical properties of the forged dome in solution treated and aged condition (STA were better than feedstock used.

  12. 锻造过程中钢锭内部孔洞型缺陷闭合规律研究%THE VOID CLOSE BEHAVIOR OF LARGE INGOTS DURING HOT FORGING

    Institute of Scientific and Technical Information of China (English)

    徐斌; 孙明月; 李殿中

    2012-01-01

    对可能影响锻造过程中大型钢锭内部孔洞型缺陷闭合的各种因素进行了系统研究.结果表明,变形温度、应变速率、摩擦系数、试样尺寸和孔洞尺寸对锻造过程中孔洞的闭合基本没有影响,而试样高径比、孔洞位置和孔洞形状对孔洞的闭合有较大影响.其中试样高径比和孔洞位置通过影响孔洞周围的应变条件来影响孔洞闭合,是间接因素.孔洞所在位置的应变越大,孔洞越容易闭合.孔洞形状是影响孔洞闭合的直接因素,也是最本质的因素.为了描述这种现象,提出了孔洞高径比的概念.模拟结果显示,沿变形方向孔洞的高径比越大,孔洞越难闭合.基于以上研究和大钢锭的实际解剖结果,提出了全新的宽砧径向压实工艺(WRF法).该工艺可使应变集中于钢锭中心区域,并满足孔洞闭合所需的最佳高径比条件,因此,可高效愈合钢锭的中心缩孔、疏松.工业实验验证了该工艺的有效性和实用性.%All the parameters that may affect void closure behavior are judged using finite element method (FEM). The simulation results show that temperature, strain rate, friction coefficient, sample size and void size do not affect the void closure behavior. Height-diameter ratio of the sample and void position will affect the strain around the void and the void will be easier to close when the strain around it are higher. Of all the parameters, void shape is the most important one. Height-diameter ratio of the void is denned to describe the effect of void shape. The simulation results show that the larger height-diameter ratio of the void, the harder it is for the void to close. Based on these results and the sectioning results of a f 00 t ingot, a new forging method, wide-anvil radial forging (WRF) is proposed. WRF method can concentrate the strain on the center of the ingot; meet the optimum height-diameter ratio condition of the void closure and heal shrinkage cavities

  13. The Effect of Corner Radii and Part Orientation on Stress Distribution of Cold Forging Die

    Directory of Open Access Journals (Sweden)

    Ahmad B.  Abdullah

    2008-01-01

    Full Text Available One of the most critical problems in cold forging is the huge stresses generated from the deformation of metal leads to die failure. The distribution of stresses mainly depends on geometry of the die. An approach to optimal design in cold forging die geometry and orientation are presented in this paper. The impression cold forging dies of the Universal joint was generated using three-dimensional CAD modeling software, SolidWorks. This CAD modeling software coupled with FEA tools, COSMOSWorks. The paper emphasizes on effect of the corner radius and dies orientation on stress distribution.

  14. Design of relief-cavity in closed-precision forging of gears

    Institute of Scientific and Technical Information of China (English)

    左斌; 王宝雨; 李智; 郑明男; 朱小星

    2015-01-01

    To reduce the difficulty of material filling into the top region of tooth in hot precision forging of gears using the alternative die designs, relief-cavity designs in different sizes were performed on the top of die tooth. The influences of the conventional process and relief-cavity designs on corner filling, workpiece stress, die stress, forming load and material utilization were examined. Finite element simulation for tooth forming, die stress and forming load using the four designs was performed. The material utilization was further considered, and the optimal design was determined. The tooth form and forming load in forging trials ensured the validity of FE simulation. Tooth accuracy was inspected by video measuring machine (VMM), which shows the hot forged accuracy achieves the level of rough machining of gear teeth. The effects of friction on mode of metal flow and strain distribution were also discussed.

  15. Large size austenitic stainless steel forgings for nuclear and cryogenic application - development, manufacturing and properties

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Keizo; Suzuki, Komei; Sato, Ikuo; Murai, Etuso (Japan Steel Works Ltd., Muroran Plant, Hokkaido (Japan))

    1992-01-01

    The high quality one-piece large austenetic stainless steel forgings are required in the several components such as nuclear reactors and run tanks for rocket engine test stand in order to assure the structural integrity and to make it easy to fabricate and inspect the components. When the austenitic stainless steel forgings are increased in size, various problems must be overcome to assure the high quality forgings. The ingot making and hot working play an important role in determining the quality of the products. In such points, the lastest manufacturing techniques such as steel making of large size ingot and hot working to get uniform and fine grains are discussed together with the fundamental data of the material properties. (orig.).

  16. 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.

  17. Design of Controlled Processing Conditions for Drop Forgings Made of Microalloy Steel Grades for Mining Industry

    Directory of Open Access Journals (Sweden)

    Skubisz P.

    2015-04-01

    Full Text Available Effect of plastic processing and controlled cooling on microstructure and mechanical properties of experimental steel grades with microalloyed with Ti, V and/or Nb, varying in the content of Mo is presented as an offer for mining industry for replacement traditionally heat-treatable hardenability grades. The goal of the work is producing microstructure condition, which after controlled hot forging and direct heat treatment, involving quenching and self-tempering, are meant to provide good combination of mechanical properties, such as TYS 800 MPa, UTS 1050 MPa, elongation to fracture at least A5 15% and/or impact strength at room temperature KCV 60 J/cm2. Hardenability assessment and dilatometric examination allowed formulation of direct heat treatment guidelines, taking into consideration fields of temperature and strain in a typical hot forging process, estimated numerically, with the use of plastometric tests results, as well as the use of unique cooling cycles after forging.

  18. The Gaia satellite: a tool for Emission Line Stars and Hot Stars

    CERN Document Server

    Martayan, Christophe; Blomme, Ronny; Jonckheere, Anthony; Borges, Marcelo; De Batz, Bertrand; Leroy, Bernard; Sordo, Rosanna; Bouret, Jean-Claude; Martins, Fabrice; Zorec, Jean; Neiner, Coralie; Nazé, Yael; Alecian, Evelyne; Floquet, Michele; Hubert, Anne-Marie; Briot, Danielle; Miroshnichenko, Anatholy; Kolka, Indrek; Stee, Philippe; Lanz, Thierry; Meynet, Georges

    2008-01-01

    The Gaia satellite will be launched at the end of 2011. It will observe at least 1 billion stars, and among them several million emission line stars and hot stars. Gaia will provide parallaxes for each star and spectra for stars till V magnitude equal to 17. After a general description of Gaia, we present the codes and methods, which are currently developed by our team. They will provide automatically the astrophysical parameters and spectral classification for the hot and emission line stars in the Milky Way and other close Local Group galaxies such as the Magellanic Clouds.

  19. Deformation, recrystallization, strength, and fracture of press-forged ceramic crystals.

    Science.gov (United States)

    Rice, R. W.

    1972-01-01

    Sapphire and ruby were very difficult to press-forge because they deformed without cracking only in a limited temperature range before they melted. Spinel crystals were somewhat easier and MgO, CaO, and TiC crystals much easier to forge. The degree of recrystallization that occurred during forging (which was related to the ease and type of slip intersections) varied from essentially zero in Al2O3 to complete (i.e., random polycrystalline bodies were produced) in CaO. Forging of bi- and polycrystalline bodies produced incoherent bodies as a result of grain-boundary sliding. Strengths of the forged crystals were comparable to those of dense polycrystalline bodies of similar grain size. However, forged and recrystallized CaO crystals were ductile at lower temperatures than dense hot-pressed CaO. This behavior is attributed to reduced grain-boundary impurities and porosity. Fracture origins could be located, indicating that fracture in the CaO occurs internally as a result of surface work hardening caused by machining.-

  20. TECHNOLOGY FOR OBTAINING BIMETALLIC SHAPING PARTS OF DIE TOOLING USING METHOD OF HIGH-SPEED HOT EXTRUSION

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2014-01-01

    Full Text Available Processes of high-speed shaping changes and especially high-speed hot extrusion create efficient conditions for treatment of weakly plastic and poorly deformable materials which are widely used in tool making facilities. Due to the fact that high-speed stamping provides accurate billets with increased mechanical properties, it can be used as a technological process for manufacturing shaping parts of die tooling parts operating which are subjected to increased loads and wear.The purpose of the paper is to carry out experimental investigations on the possibility to obtain a bimetallic tool where structural steel is considered as a basis of the tool and a working cavity is made of high-alloyed tool steel with its saving up to 90 %. A scheme of loading and geometry of conjugated surfaces of the composite billet have been developed in the paper. Technology for obtaining bimetallic shaping parts of die tooling with deformation at speed of vR = 40-50 m/s and composite billet temperature of T = 1150 °C has been experimentally tested with formation of a compound due to plastic flow of two billet parts on contact surface with removal of surface oxide films.Microstructures of the bimetallic compounds obtained with the help of high-speed hot extrusion method for compositions of structural and high-alloy steels have been investigated and their high quality has been proved during the investigations. Dependences of micro-hardness distribution have been established outbound two- steel contact plane in the zone of connection that are characterized by a minimum micro-hardness value in the connection joint. Availability of more plastic zone in the contact plane contributes to reduction of residual stresses due to their relaxation in this zone and higher joint strength.

  1. Modeling microstructure evolution in the delta process forging of superalloy IN718 turbine discs

    Science.gov (United States)

    Zhang, Haiyan; Zhang, Shihong; Cheng, Ming; Zhao, Zhong

    2013-05-01

    The microstructure development in the Delta Process (DP) forging of Superalloy IN718 turbine discs were predicted using the combined approach of axisymmetric finite element simulation and modeling for the dynamic recrystallization and grain growth. In order to establish the deformation constitutive equation and dynamic recrystallization models for the DP process of Superalloy IN718, the isothermal compression tests were carried out in the temperature range 950 to 1010 °C and strain rates range 0.001 to0.1s-1. Moreover, the isothermal heat treatment tests after hot deformation were conducted in the temperature range 950 to 1040°C to generate the grain growth model. The experimental results indicated the existence of the δ phase could make the activation energy of deformation increase. Furthermore, the existence of the δ phase could stimulate the occurrence of dynamic recrystallization, and the grain growth was restrained due to the pinning effect of δ phase. The predicted grain size and its distribution in the DP forging of Superalloy IN718 turbine discs were compared with the actual microstructures deformed by the hot die forging. It was found that the forging with uniform fine grains could be obtained by the application of DP process to the forging of the turbine disk, in which the alloy was pre-precipitated δ phase after the baiting in the original process.

  2. 长轴类大锻件自由锻造工艺研究%Research on free-forging process of long-shaft heavy forging

    Institute of Scientific and Technical Information of China (English)

    张鹏; 夏琴香; 李哲林; 谢合清; 潘勇

    2011-01-01

    The traditional forging technology was studied and improved. The 7. 8 t propeller-shaft heavy forging was forged through the 4 t electrohydraulic hammer using the reasonable steel ingot and by squaring with 300 mm width flat anvil, stretching, chamfering and rolling processes. Experimental result shows that the defects, such as the shrinkage cavity, porosity, etc., can be clogged by the reasonable forging process. High mechanical properties of the propeller shaft heavy forgings were obtained after quenching and tempering. The characteristics of simple tool, broad universal and large flexible of free forging were fully utilized in this research. The free-forging of long-shaft heavy forging was realized.%对传统的锻造工艺进行了研究和改进,通过合理选用钢锭及采用宽300 mm平砧压方、拔长、倒棱滚圆等工序,实现用4 t电液锤锻造7.8 t螺旋桨轴大锻件.试验结果证明,合理的锻造工艺路线锻合了钢锭内部的缩孔、疏松等缺陷,所获得的螺旋桨轴大锻件经过锻后调质热处理能得到较好的综合力学性能.项目的研究充分发挥了自由锻造工具简单、通用性强、灵活性大的特点,实现了长轴类大锻件的自由锻造.

  3. RESEARCH ON KNOWLEDGE-BASED CAPP SYSTEM FOR ROTOR FORGING

    Institute of Scientific and Technical Information of China (English)

    Wang Leigang; Deng Dongrnei; Liu Zhubai

    2000-01-01

    Guided by developing forging technology theory,designing rules on rotor forging process are summed up.Knowledge-based CAPP system for rotor forging is created.The system gives a rational and optimum process.

  4. 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...... in the range 30-150°C. Above this temperature range friction increases. As regards lubricant performance Lubrication Limit Curves (LLC) are plotted in a sliding length-surface enlargement diagram with the tool temperature as a parameter. Larger tool temperature implies lower acceptable surface expansion...

  5. 超大筒节锻造工艺的优化%Optimization of Forging Process for Large Shell Ring

    Institute of Scientific and Technical Information of China (English)

    施熔刚; 张强升; 姜述杰; 张丽丹

    2013-01-01

    通过设计辅助工具方法及简化锻造工序对原有超大筒节锻件工艺进行改进,将原来锻造6火次出成品的锻造工艺改为4火次出成品,在确保产品质量的同时,有效的降低锻造生产成本,提高锻造生产效率.%The original forging process for large shell ring forging was improved through the methods of designing aid tools and simplifying forging process,that is,the original forging process of 6 fire times was instead of that of 4 fire times.The improved forging process can ensure product quality,reduce production costs and improve production efficiency.

  6. Application of Magnetic Kinds of Nondestructive Inspection to Parts From Die Tool Steels

    Science.gov (United States)

    Kornilova, A. V.; Selishchev, A. I.; Idarmachev, I. M.

    2016-01-01

    Possibilities of control of the level of accumulated damage in dies for cold and hot forming as a function of the coercivity are considered. The coercivity of the material of dies for hot forging and cold stamping is studied. Formulas are obtained for determining the coercivity in steels for hot die forging in the state as delivered.

  7. Research on Forging Die Design Ontology

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wenlei; FAN Yushun

    2006-01-01

    Forging die design is heavily dependent on engineers' experiences. But traditional AI technologies can barely provide a standard knowledge representation style for knowledge transferring. This paper introduces ontology into forging die design. 3-layer forging die design ontology is built, which includes Meta-ontology, Domain-ontology and Bottom ontology. Further, by conceptualization, the concepts and their relations are formally addressed by primitives such as Term, Relation and Function etc, which are explicitly expressed by concept tree. Bottom ontology uses Knowledge Item and Prototype to represent and capture general knowledge for knowledge reuse and share. Forging die design ontology building approach is discussed for standard knowledge representation, knowledge mine and knowledge driven CAD design etc. And OWL language is employed for integration among different domain ontologies integration. Finally a locomotive forging die KBE system is presented to demonstrate this approach.

  8. 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...... of normal pressure and tool/work piece interface temperature. The model is verified by process testing measuring friction at varying reduction in cold forward rod extrusion....

  9. Machinability of Hastelloy C-276 Using Hot-pressed Sintered Ti(C7N3)-based Cermet Cutting Tools

    Institute of Scientific and Technical Information of China (English)

    XU Kaitao; ZOU Bin; HUANG Chuanzhen; YAO Yang; ZHOU Huijun; LIU Zhanqiang

    2015-01-01

    C-276 nickel-based alloy is a difficult-to-cut material. In high-speed machining of Hastelloy C-276, notching is a prominent fallure mode due to high mechanical properties of work piece, which results in the short tool life and low productivity. In this paper, a newly developed Ti(C7N3)-based cermet insert manufactured by a hot-pressing method is used to machine the C-276 nickel-based alloy, and its cutting performances are studied. Based on orthogonal experiment method, the influence of cutting parameters on tool life, material removal rates and surface roughness are investigated. Experimental research results indicate that the optimal cutting condition is a cutting speed of 50 m/min, depth of cut of 0.4 mm and feed rate of 0.15 mm/r if the tool life and material removal rates are considered comprehensively. In this case, the tool life is 32 min and material removal rates are 3000 mm3/min, which is appropriate to the rough machining. If the tool life and surface roughness are considered, the better cutting condition is a cutting speed of 75 m/min, depth of cut of 0.6 mm and feed rate of 0.1 mm/r. In this case, the surface roughness is 0.59mm. Notch wear, flank wear, chipping at the tool nose, built-up edge(BUE) and micro-cracks are found when Ti(C7N3)-based cermet insert turned Hastelloy C-276. Oxidation, adhesive, abrasive and diffusion are the wear mechanisms, which can be investigated by the observations of scanning electron microscope and energy-dispersive spectroscopy. This research will help to guide studies on the evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy C-276 machining.

  10. Investigation of crack propagation in X38CrMoV5 (AISI H11) tool steel at elevated temperatures

    OpenAIRE

    Shah, Masood; Mabru, Catherine; Rezaï-Aria, Farhad

    2010-01-01

    A method is developed to evaluate the surface fatigue damage of hot forming tools (forging, HPDC) that undergo thermo mechanical loading and environmental attack. Crack propagation under fatigue loading in a hot work tool steel X38CrMoV5-47HRC is investigated using SENT (single edge notched tension) specimens of 2.5*8 mm*mm section. The effect of different testing conditions has been investigated: effect of thickness (ranging from 2.5mm – 0.10mm), effect of R value and effect of temperature a...

  11. Design and Improve Forging Mould of Squareness Bol%方头螺栓的锻造模具的设计与改进

    Institute of Scientific and Technical Information of China (English)

    连厚富; 齐永丰

    2014-01-01

    通过对方头螺栓胎模锻与自由锻优点的比较,介绍了通过充分利用胎模来生产锻件,可达到不断降低锻件毛坯重量,减少加工工时目的。设计合理的锻膜结构和不断改进锻模结构,是该工艺的关键。%By comparing the advantages between loose tooling forging with the free forging on forging square-head bolt , it is introduced that by utilizing membranes to produce forging can achieve forging blank to decrease weight and reduce the processing time . Reasonable design of forging die structure , mem-brane structure and the continuous improvement is the key to this process .

  12. Microstructure Evolution of Multi-Heat Forging and Numerical Simulation for 316LN Steel

    Directory of Open Access Journals (Sweden)

    Duan Xing-Wang

    2014-02-01

    Full Text Available Microstructure evolution has been studied by multi-heat forging experiments and numerical simulation in order to determine the reasonable forging technology of 316 LN steel. The microstructure evolution models were obtained by hot compressive tests and heat treatment tests of 316 LN steels. The one-heat and three-heat upsetting experiments were carried on. Meanwhile, the corresponding numerical simulations were performed. The results show that, the grain uniformity of three-heat upsetting is much better that of one-heat upsetting. The average grain size of three-heat upsetting is smaller than that of one-heat upsetting. So, the forging technology of multi-heat and little deformation should be adopted for 316 LN steel forging. By comparing experimental average grain sizes with simulated average grain sizes for three-heat upsetting, it is found that the simulated values are in agreement with experimental values, which shows that the numerical simulation can be employed to predict the forging microstructure evolution of 316 LN steel.

  13. Effect of Forging on Microstructure, Texture, and Uniaxial Properties of Cast AZ31B Alloy

    Science.gov (United States)

    Toscano, D.; Shaha, S. K.; Behravesh, B.; Jahed, H.; Williams, B.

    2017-07-01

    The effect of open-die hot forging on cast AZ31B magnesium alloy was investigated in terms of the evolution of microstructure, texture, and mechanical properties. A refined microstructure with strong basal texture was developed in forged material. A significant increase in tensile yield and ultimate strengths by 143 and 23%, respectively, was determined as well. When tested in compression at room temperature, the forged alloy displayed significant in-plane asymmetry and unchanged yield strength compared to the cast alloy owing to the activation of 10\\bar{1}2} Microstructure and texture analysis of the fracture samples confirmed that the deformation of the forged samples was dominated by slip during tension and twin in compression. In comparison, both slip and twin were observed in the cast samples for similar testing conditions. The increase in strength of forging was attributed to the refinement of grains and the formation of strong basal texture, which activated the non-basal slip on the prismatic and pyramidal slip systems instead of extension twin.

  14. Study of Casting and Solidification of Slab Ingot from Tool Steel Using Numerical Modelling / Modelowanie Numeryczne Odlewania I Krzepnięcia Wlewków Stalowych Ze Stali Narzędziowej

    Directory of Open Access Journals (Sweden)

    Tkadlečková M.

    2015-12-01

    Full Text Available The main problem in the production of forgings from tool steels, especially thick plates, blocks, pulleys and rods which are used for special machine components for demanding applications, it is the inhomogeneous structure with segregations, cracks in segregations or complex type of non-metallic inclusions MnS and TiCN. These forgings are actually produced from conventional forging ingots. Due to the size of forgings, it would be interesting the production of these forgings from slab ingots. It is possible that the production of forgings from slab ingots (which are distinguished by a characteristic aspect ratio A/B, it would reduce the occurrence of segregations. The paper presents the verification of the production process of slab steel ingots in particular by means of numerical modelling using finite element method. The paper describes the pre-processing, processing and post-processing phases of numerical modelling. The attention was focused on the prediction of behavior of hot metal during the mold filling, on the verification of the final porosity, of the final segregation and on the prediction of risk of cracks depending on the actual geometry of the mold.

  15. Rational development of solid dispersions via hot-melt extrusion using screening, material characterization, and numeric simulation tools.

    Science.gov (United States)

    Zecevic, Damir E; Wagner, Karl G

    2013-07-01

    Effective and predictive small-scale selection tools are inevitable during the development of a solubility enhanced drug product. For hot-melt extrusion, this selection process can start with a microscale performance evaluation on a hot-stage microscope (HSM). A batch size of 400 mg can provide sufficient materials to assess the drug product attributes such as solid-state properties, solubility enhancement, and physical stability as well as process related attributes such as processing temperature in a twin-screw extruder (TSE). Prototype formulations will then be fed into a 5 mm TSE (~1-2 g) to confirm performance from the HSM under additional shear stress. Small stress stability testing might be performed with these samples or a larger batch (20-40 g) made by 9 or 12 mm TSE. Simultaneously, numeric process simulations are performed using process data as well as rheological and thermal properties of the formulations. Further scale up work to 16 and 18 mm TSE confirmed and refined the simulation model. Thus, at the end of the laboratory-scale development, not only the clinical trial supply could be manufactured, but also one can form a sound risk assessment to support further scale up even without decades of process experience.

  16. Mechanics and forming theory of liquid metal forging

    Institute of Scientific and Technical Information of China (English)

    罗守靖; 姜巨福; 王迎; 藤东东

    2003-01-01

    On the basis of steel liquid forging and aluminium alloy liquid forging, liquid metal forging was investigated, such as the assembly model, metal plastic flowing, the force-displacement curves, the harmonious equation, calculation of value of altitude deformation and determination of specific pressure of liquid metal forging. On the basis of the theory of metal plastic forming and the characteristics of liquid metal forging, the achievements on the mechanics and forming theory of liquid metal forging were given out by combining the theory and experiments systematically, and an important preparation for establishing liquid metal forging theory was suggested.

  17. International cooperation in cold forging technology

    DEFF Research Database (Denmark)

    Bay, Niels; Lange, K

    1992-01-01

    of the ICFG are personally elected by the Plenary as experts within the field, often representing national groups within cold forging. The main work within the ICFG is carried out in its subgroups which are established by the Plenary to collect, compile and evaluate data and eventually also produce data......International cooperation in the field of cold forging technology started in 1961 by formation of the OECD Group of Experts on Metal Forming. In 1967 this group was transformed into the International Cold Forging Group, ICFG, an independent body which has now been operative for 25 years. Members...

  18. Processing and Characterization of Sub-delta Solvus Forged Hemispherical Forgings of Inconel 718

    Science.gov (United States)

    Chenna Krishna, S.; Rao, G. Sudarasana; Singh, Satish Kumar; Narayana Murty, S. V. S.; Venkatanarayana, G.; Jha, Abhay K.; Pant, Bhanu; Venkitakrishnan, P. V.

    2016-12-01

    In this paper, microstructure and mechanical properties of 200 mm diameter Inconel 718 hemispherical domes processed at 1025 °C through closed die hammer forging have been investigated. Microstructure and mechanical properties of the forgings in radial and tangential directions were characterized using optical microscopy, scanning electron microscopy, impact testing, and tensile testing. Grain size of the forgings at three different locations was fine with an average grain size of ASTM No. 8-9. The typical tensile properties of the forgings in solution-treated and aged condition were ultimate tensile strength-1450 MPa, yield strength-1240 MPa, and ductility-25%. The fine grain size achieved in forgings has been attributed to delta phase present at grain boundaries which pinned the grains during forging and prevented grain coarsening.

  19. Functional properties of surface layers of X38CrMoV5-3 hot work tool steel alloyed with HPDL laser

    OpenAIRE

    L.A. Dobrzański; M. Piec; K. Labisz; M. Bonek; A. Klimpel

    2007-01-01

    Purpose: Improvement of functional properties alloyed of hot work tool steel surface layers is one of the goals of this paper.Design/methodology/approach: The material used for investigation was the hot work tool steel X38CrMoV5-3. Remelting and alloying of surface layers were made using the HPDL high power diode laser Rofin DL 020 in the laser power range of 1.2-2.3 kW. The carbide powders were applied on specimens prepared and degreased in this way; the powder was mixed with the sodium glas...

  20. A method for manufacturing a tool part for an injection molding process, a hot embossing process, a nano-imprint process, or an extrusion process

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a method for manufacturing a tool part for an injection molding process, a hot embossing process, nano-imprint process or an extrusion process. First, there is provided a master structure (10) with a surface area comprising nanometre-sized protrusions (11) with a ......The present invention relates to a method for manufacturing a tool part for an injection molding process, a hot embossing process, nano-imprint process or an extrusion process. First, there is provided a master structure (10) with a surface area comprising nanometre-sized protrusions (11...

  1. INFLUENCE OF QUANTITATIVE ALLOYING OF TOOL STEELS FOR HOT DEFORMATION ON THE LEVEL OF HARDENING

    Directory of Open Access Journals (Sweden)

    V. N. Fedulov

    2015-01-01

    Full Text Available The influence of complexly experimental tool steels: C (0,4–0,50%, Si (0,6–1,2%, Mn (0,17–0,8%, Cr (0,8–3%, W (0,9– 4%, Mo (0,01–3.5% and V (0,28–1,8% on their ability to hardening due to only high-temperature tempering after induction melting, casting in the ceramic mold and air cooling (without deformation and after the various modes of complete heat treatment cycle

  2. Forging of FeAl intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Flores, O.; Juarez, J.; Campillo, B.; Martinez, L. [UNAM, Cuernavaca (Mexico). Lab. de Cuernavaca; Schneibel, J.H. [Oak Ridge National Lab., TN (United States)

    1994-09-01

    Much activity has been concentrated on the development of intermetallic compounds with the aim of improving tensile ductility, fracture toughness and high notch sensitivity in order to develop an attractive combination of properties for high and low temperature applications. This paper reports experience in processing and forging of FeAl intermetallic of B2 type. During the experiments two different temperatures were employed, and the specimens were forged after annealing in air, 10{sup {minus}2} torr vacuum and argon. From the results it was learned that annealing FeAl in argon atmosphere prior to forging resulted in better deformation behavior than for the other two environments. For the higher forging temperature used in the experiments (700C), the as-cast microstructure becomes partially recrystallized.

  3. Mechanical Testing Development for Reservoir Forgings

    Energy Technology Data Exchange (ETDEWEB)

    Wenski, E.G.

    2000-05-22

    The goal of this project was to determine the machining techniques and testing capabilities required for mechanical property evaluation of commercially procured reservoir forgings. Due to the small size of these specific forgings, specialized methods are required to adequately machine and test these sub-miniature samples in accordance with the requirements of ASTM-E8 and ASTM-E9. At the time of project initiation, no capability existed at Federal Manufacturing & Technologies (FM&T) to verify the physical properties of these reservoirs as required on the drawing specifications. The project determined the sample definitions, machining processes, and testing procedures to verify the physical properties of the reservoir forgings; specifically, tensile strength, yield strength, reduction of area, and elongation. In addition, a compression test method was also developed to minimize sample preparation time and provide a more easily machined test sample while maintaining the physical validation of the forging.

  4. Modeling heat stress effect on Holstein cows under hot and dry conditions: selection tools.

    Science.gov (United States)

    Carabaño, M J; Bachagha, K; Ramón, M; Díaz, C

    2014-12-01

    Data from milk recording of Holstein-Friesian cows together with weather information from 2 regions in Southern Spain were used to define the models that can better describe heat stress response for production traits and somatic cell score (SCS). Two sets of analyses were performed, one aimed at defining the population phenotypic response and the other at studying the genetic components. The first involved 2,514,762 test-day records from up to 5 lactations of 128,112 cows. Two models, one fitting a comfort threshold for temperature and a slope of decay after the threshold, and the other a cubic Legendre polynomial (LP) model were tested. Average (TAVE) and maximum daily temperatures were alternatively considered as covariates. The LP model using TAVE as covariate showed the best goodness of fit for all traits. Estimated rates of decay from this model for production at 25 and 34°C were 36 and 170, 3.8 and 3.0, and 3.9 and 8.2g/d per degree Celsius for milk, fat, and protein yield, respectively. In the second set of analyses, a sample of 280,958 test-day records from first lactations of 29,114 cows was used. Random regression models including quadratic or cubic LP regressions (TEM_) on TAVE or a fixed threshold and an unknown slope (DUMMY), including or not cubic regressions on days in milk (DIM3_), were tested. For milk and SCS, the best models were the DIM3_ models. In contrast, for fat and protein yield, the best model was TEM3. The DIM3DUMMY models showed similar performance to DIM3TEM3. The estimated genetic correlations between the same trait under cold and hot temperatures (ρ) indicated the existence of a large genotype by environment interaction for fat (ρ=0.53 for model TEM3) and protein yield (ρ around 0.6 for DIM3TEM3) and for SCS (ρ=0.64 for model DIM3TEM3), and a small genotype by environment interaction for milk (ρ over 0.8). The eigendecomposition of the additive genetic covariance matrix from model TEM3 showed the existence of a dominant

  5. A Numerical Modelling Approach for Time-Dependent Deformation of Hot Forming Tools under the Creep-Fatigue Regime

    Directory of Open Access Journals (Sweden)

    B. Reggiani

    2016-01-01

    Full Text Available The present study was aimed at predicting the time-dependent deformation of tools used in hot forming applications subjected to the creep-fatigue regime. An excessive accumulated plastic deformation is configured as one of the three main causes of premature failure of tools in these critical applications and it is accumulated cycle by cycle without evident marks leading to noncompliant products. With the aim of predicting this accumulated deformation, a novel procedure was developed, presented, and applied to the extrusion process as an example. A time-hardening primary creep law was used and novel regression equations for the law’s coefficients were developed to account not only for the induced stress-temperature state but also for the dwell-time value, which is determined by the selected set of process parameters and die design. The procedure was validated against experimental data both on a small-scale extrusion die at different stress, temperature, load states, and for different geometries and on an industrial extrusion die which was discarded due to the excessive plastic deformation after 64 cycles. A numerical-experimental good agreement was achieved.

  6. Metallurgical modelling of superalloy disc isothermal forgings

    Science.gov (United States)

    Evans, R. W.

    1988-08-01

    The metallurgical structure of superalloy aeroengine disc forgings is a complex function of the forging operation parameters and the post forging heat treatment. It is often desirable to obtain certain specific structures in parts of the disc which are, for instance, resistant to crack propagation and this has traditionally been accomplished by means of a series of production trials. This expensive and time consuming procedure can be considerably shortened if the development of microstructure during the forging can be accurately modelled by a suitable computer code. Described here is such a model and its use in the design of isothermal forged components. The model discribed is a fully thermally coupled viscoplasticity finite element algorithm. It treats nodal velocities as the basic unknowns and both the mesh geometry and the various metallurgical structural terms are updated by a single step Euler scheme. Facilities are available for ensuring that surface nodes follow die shapes after impingement, that flow is incompressible and that suitable surface friction forces are applied. Throughout the whole forging process (which may involve the re-meshing of severely distorted elements), the metallurgical history of elements is retained so that the effects of subsequent heat treatments can be assessed.

  7. Intelligent Control of a Novel Hydraulic Forging Manipulator

    Directory of Open Access Journals (Sweden)

    J. Wang

    2011-01-01

    Full Text Available The increased demand for large-size forgings has led to developments and innovations of heavy-duty forging manipulators. Besides the huge carrying capacity, some robot features such as force perception, delicacy and flexibility, forging manipulators should also possess. The aim of the work is to develop a heavy-duty forging manipulator with robot features by means of combination of methods in mechanical, hydraulic, and control field. In this paper, through kinematic analysis of a novel forging manipulator, control strategy of the manipulator is proposed considering the function and motion of forging manipulators. Hybrid pressure/position control of hydraulic actuators in forging manipulator is realized. The feasibility of the control method has been verified by the experiments on a real prototype of the novel hydraulic forging manipulator in our institute. The intelligent control of the forging manipulator is performed with programmable logic controller which is suitable for industrial applications.

  8. Shrinking of bumps by drawing scintillating fibres through a hot conical tool

    CERN Document Server

    Rodrigues Cavalcante, Ana Barbara; Gavardi, Laura; Joram, Christian; Kristic, Robert; Pierschel, Gerhard; Schneider, Thomas

    2016-01-01

    The LHCb SciFi tracker will be based on scintillating fibres with a nominal diameter of 250 $\\mu$m. A small length fraction of these fibres shows millimetre-scale fluctuations of the diameter, also known as bumps and necks. In particular, bumps exceeding a diameter of about 350 $\\mu$m are problematic as they can distort the winding pattern of the fibre mats over more extended regions. We present a method to reduce the diameter of large bumps to a diameter of 350 $\\mu$m by locally heating and pulling the fibre through a conical tool. The method has been proven to work for bumps up to 450 – 500 $\\mu$m diameter. Larger bumps need to be treated manually by a cut-and-glue technique which relies on UV-curing instant glue. The bump shrinking and cut-and-glue processes were integrated in a fibre diameter scanner at CERN. The central scanning and bump shrinking of all fibres is expected to minimise bump related issues at the four mat winding centres of the SciFi project.

  9. Modelling of Damage During Hot Forging of Ingots

    DEFF Research Database (Denmark)

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

    2013-01-01

    the damage analysis on the Cockcroft & Latham criterion, since this with changing cut-off value does not inconsistently change the location of damage, in contradiction to the other investigated criteria, and since it is able to predict damage in processes, which are slightly compressive....

  10. 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.

  11. Effect of key factors on cold orbital forging of a spur bevel gear

    Institute of Scientific and Technical Information of China (English)

    庄武豪; 董丽颖

    2016-01-01

    Cold orbital forging is an advanced spur bevel gear forming technology. Generally, the spur bevel gear in the cold orbital forging process is formed by two steps: the preforming step and the final step. Due to the great importance of the final step to gear forming and its complication with interactive factors, this work aims at examining the influence of key factors on the final step in cold orbital forging of a spur bevel gear. Using the finite element (FE) method and control variate method, the influence rules of four key factors, rotation velocity of the upper tool,n, feeding velocity of the lower tool,v, tilted angle of the upper tool,γ, friction factor between the tools and the billet,m, on the geometry and the deformation inhomogeneity of the cold orbital forged gear are thoroughly clarified. The research results show that the flash becomes more homogeneous with increasingv, increasingm, decreasing n or decreasingγ. And the deformation of the gear becomes more homogeneous with increasingv, decreasingn or decreasingγ. Finally, a corresponding experiment is conducted, which verifies the accuracy of FE simulation conclusions.

  12. Theoretical study on Cold Open Die Forging Process Optimization for Multipass Workability

    Directory of Open Access Journals (Sweden)

    Gaikwad Ajitkumar

    2016-01-01

    Full Text Available Cold Workability limits strength enhancement of austenitic materials through cold deformation. The intrinsic workability is the material characteristic whereas state-of-stress workability is governed by nature of applied stress, strain rate and geometry of deformation zone. For Cold Open Die Forging (CODF, multipass workability is essential. In this work, FEM tool FORGE-3 is used to optimize CODF on hydraulic press by analysis of stress-strain profiles and use of Latham-Cockroft damage criterion. Study recommends optimized process parameters, die combinations and pass-schedules.

  13. Size Effects in Residual Stress Formation during Quenching of Cylinders Made of Hot-Work Tool Steel

    Directory of Open Access Journals (Sweden)

    Manuel Schemmel

    2015-01-01

    Full Text Available The present work investigates the residual stress formation and the evolution of phase fractions during the quenching process of cylindrical specimens of different sizes. The cylinders are made of hot-work tool steel grade X36CrMoV5-1. A phase transformation kinetic model in combination with a thermomechanical model is used to describe the quenching process. Two phase transformations are considered for developing a modelling scheme: the austenite-to-martensite transformation and the austenite-to-bainite transformation. The focus lies on the complex austenite-to-bainite transformation which can be observed at low cooling rates. For an appropriate description of the phase transformation behaviour nucleation and growth of bainite are taken into account. The thermomechanical model contains thermophysical data and flow curves for each phase. Transformation induced plasticity (TRIP is modelled by considering phase dependent Greenwood-Johnson parameters for martensite and bainite, respectively. The influence of component size on residual stress formation is investigated by the finite element package Abaqus. Finally, for one cylinder size the simulation results are validated by X-ray stress measurements.

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

    DEFF Research Database (Denmark)

    Jinming, Sha

    is undergoing vibration. In the experiments, die surface orientation, frequency and amplitude of vibration, vibrating wave form and the direction of vibration has been taken into account as the parameters which influence friction behaviour in forging process. The results reveal that friction could be reduced up......The objective of this thesis is to fundamentally study the influence of die surface vibration on friction under low frequency in metal forging processes. The research includes vibrating tool system design for metal forming, theoretical and experimental investigations, and finite element simulations...... on die surface vibration in forging process. After a general introduction to friction mechanisms and friction test techniques in metal forming, the application of ultrasonic vibration in metal forming, the influence of sliding velocity on friction is described. Some earlier investigations...

  15. Effects of Different Forging Processes on Microstructure Evolution for 316LN Austenitic Stainless Steel

    Science.gov (United States)

    Sui, Dashan; Zhu, Lingling; Wang, Tao; Zhang, Peipei; Cui, Zhenshan

    2017-07-01

    Forging experiments were designed and carried out on a 3150 kN hydraulic press to investigate the effects of different processes on the microstructure evolution for 316LN steel. The forging processes included single-pass (upsetting) and multipass (stretching) deformations, and the experimental results indicated that the average grain size varied with forging processes. Moreover, the size had distinct differences at different positions in the workpiece. Meanwhile, numerical simulations were implemented to study the influence of temperature, strain, and strain rate on microstructure evolution. The results of experiments and simulations comprehensively demonstrated that dynamic, static, and meta-dynamic recrystallization could coexist in the hot forging process and that the recrystallization process could easily occur under the conditions of higher temperature, larger strain, and higher strain rate. Moreover, the temperature had more significant influence on both recrystallization and grain growth. A higher temperature could not only promote the recrystallization but also speed up the grain growth. Therefore, a lower temperature is beneficial to obtain refinement grains on the premise that the recrystallization can occur completely.

  16. 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.

  17. A Knowledge base model for complex forging die machining

    OpenAIRE

    Mawussi, Kwamiwi; Tapie, Laurent

    2011-01-01

    International audience; Recent evolutions on forging process induce more complex shape on forging die. These evolutions, combined with High Speed Machining (HSM) process of forging die lead to important increase in time for machining preparation. In this context, an original approach for generating machining process based on machining knowledge is proposed in this paper. The core of this approach is to decompose a CAD model of complex forging die in geometric features. Technological data and ...

  18. HPPMS (Cr1-xAlx)N WSy Coatings for the Application in Dry Cold Forging of Steel: Sythesis and Raman Characterization

    OpenAIRE

    Bobzin, Kirsten

    2016-01-01

    Lubricants are applied to reduce friction between workpieces and forming tools in cold forging processes. There is a strong demand to avoid lubricants due to economic, ecological and legislative aspects. PVD coatings took over the tasks of lubricants in numerous applications in the recent years. They may enormously reduce tool and workpiece wear in cold forging or deliver special functions even in the absence of lubricants. However, the abdication of lubricants goes along with the requirement...

  19. Single Nanoparticle Mass Spectrometry as a High Temperature Kinetics Tool: Sublimation, Oxidation, and Emission Spectra of Hot Carbon Nanoparticles.

    Science.gov (United States)

    Howder, Collin R; Long, Bryan A; Gerlich, Dieter; Alley, Rex N; Anderson, Scott L

    2015-12-17

    In single nanoparticle mass spectrometry, individual charged nanoparticles (NPs) are trapped in a quadrupole ion trap and detected optically, allowing their mass, charge, and optical properties to be monitored continuously. Previous experiments of this type probed NPs that were either fluorescent or large enough to detect by light scattering. Alternatively, small NPs can be heated to temperatures where thermally excited emission is strong enough to allow detection, and this approach should provide a new tool for measurements of sublimation and surface reaction kinetics of materials at high temperatures. As an initial test, we report a study of carbon NPs in the 20-50 nm range, heated by 10.6 μm, 532 nm, or 445 nm lasers. The kinetics for sublimation and oxidation of individual carbon NPs were studied, and a model is presented for the factors that control the NP temperature, including laser heating, and cooling by sublimation, buffer gas collisions, and radiation. The estimated NP temperatures were in the 1700-2000 K range, and the NP absorption cross sections ranged from ∼0.8 to 0.2% of the geometric cross sections for 532 nm and 10.6 μm excitation, respectively. Emission spectra of single NPs and small NP ensembles show a feature in the IR that appears to be the high energy tail of the thermal (blackbody-like) emission expected from hot particles but also a discrete feature peaking around 750 nm. Both the IR tail and 750 nm peak are observed for all particles and for both IR and visible laser excitation. No significant difference was observed between graphite and amorphous carbon NPs.

  20. 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...

  1. 29 CFR 1910.218 - Forging machines.

    Science.gov (United States)

    2010-07-01

    ... a man to reach the full length of the die without placing his hand or arm between the dies. (vii... specifications or dimensions shown in Table O-11. (2) Hydraulic forging presses. When dies are being changed or maintenance is being performed on the press, the following shall be accomplished: (i) The hydraulic pumps and...

  2. Influence of die geometry and material selection on the behavior of protective die covers in closed-die forging

    Science.gov (United States)

    Yu, Yingyan; Rosenstock, Dirk; Wolfgarten, Martin; Hirt, Gerhard

    2016-10-01

    Due to the fact that tooling costs make up to 30% of total costs of the final forged part, the tool life is always one main research topic in closed-die forging [1]. To improve the wear resistance of forging dies, many methods like nitriding and deposition of ceramic layers have been used. However, all these methods will lose its effect after a certain time, then tool repair or exchange is needed, which requires additional time and costs. A new method, which applies an inexpensive and changeable sheet metal on the forging die to protect it from abrasive wear, was firstly proposed in [2]. According to the first investigation, the die cover is effective for decreasing thermal and mechanical loads, but there are still several challenges to overcome in this concept, like wrinkling and thinning of the die cover. Therefore, an experimental study using different geometries and die cover materials is presented within this work. The results indicate the existence of feasible application cases of this concept, since conditions are found under which a die cover made of 22MnB5 still keeps its original shape even after 7 forging cycles.

  3. Protostars: forge of cosmic rays?

    CERN Document Server

    Padovani, M; Hennebelle, P; Ferrière, K

    2016-01-01

    Galactic cosmic rays (CR) are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy as well as their ionisation efficiency because of the presence of magnetic fields and collisions with molecular hydrogen. Recent observations hint at high levels of ionisation and to the presence of synchrotron emission in protostellar systems, therefore leading to an apparent contradiction. We want to explain the origin of these CRs accelerated within young protostars as suggested by observations. Our modelling consists of a set of conditions that has to be satisfied in order to have an efficient CR acceleration through diffusive shock acceleration. We analyse three main acceleration sites, then we follow the propagation of these particles through the protostellar system up to the hot spot region. We find that jet shocks can be strong accelerators of CR protons, which can be boosted up to relativistic energies. Another ...

  4. Forging Operation for Super-Large Main Shaft of Water Turbines%超大型轮机主轴锻造

    Institute of Scientific and Technical Information of China (English)

    胡晓琦; 张建国; 季雪; 牛广斌

    2014-01-01

    某大型轮机主轴法兰直径φ2.65 m,总长近10 m,锻件重达150 t,其规格超出水压机车间现有附具的工作范围,很难用传统锻造方法进行整体锻造生产。为此设计出一种新的锻造方法并对现有附具进行改造,最终成功锻造出形状和尺寸合格的大型轮机主轴锻件。%The main shaft of a large water turbine has a flange diameter ofφ2.65 m and is 10 m long. The weight of the main shaft forging is 150 t. Such large forging can not be made with the operational tools of the forging workshop and the monobloc forging is difficult to make with conventional forging operation. For this reason, a new forging process is designed and the operational tools are modified. With this effort, the large main shaft forging that has acceptable shape and dimensions is made successfully.

  5. Tribological Investigations of Hard-Faced Layers and Base Materials of Forging Dies with Different Kinds of Lubricants Applied

    Directory of Open Access Journals (Sweden)

    V. Lazić

    2010-12-01

    Full Text Available This paper gives a procedure for choosing the right technology for reparative hard facing of damaged forging dies. Since they are subject to impact loads and cyclic temperature elevations, forging dies should be made of steel that is able to withstand great impact loads, maintain good mechanical properties at elevated temperatures and that is resistant to wear and thermal fatigue. For these reasons, forging dies are made of conditionally weldable alloy tool steels; however it makes hard facing of damaged tools even more difficult. In this paper, wear resistance of base materials, hard-faced layers and heat-affected zones are tribologically investigated when two different lubricants - pure synthetical oil LM 76 and LM 76 with 6% molybdenum disulfide (MoS2 are applied. Tribological investigations have shown that the wear resistance of the hard faced layers is considerably greater than the wear resistance of the base material. However, the base material has better properties concerning friction.

  6. 2014 Accomplishments-Tritium aging studies on stainless steel: Fracture toughness properties of forged stainless steels-Effect of hydrogen, forging strain rate, and forging temperature

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-01

    Forged stainless steels are used as the materials of construction for tritium reservoirs. During service, tritium diffuses into the reservoir walls and radioactively decays to helium-3. Tritium and decay helium cause a higher propensity for cracking which could lead to a tritium leak or delayed failure of a tritium reservoir. The factors that affect the tendency for crack formation and propagation include: Environment; steel type and microstructure; and, vessel configuration (geometry, pressure, residual stress). Fracture toughness properties are needed for evaluating the long-term effects of tritium on their structural properties. Until now, these effects have been characterized by measuring the effects of tritium on the tensile and fracture toughness properties of specimens fabricated from experimental forgings in the form of forward-extruded cylinders. A key result of those studies is that the long-term cracking resistance of stainless steels in tritium service depends greatly on the interaction between decay helium and the steels’ forged microstructure. New experimental research programs are underway and are designed to measure tritium and decay helium effects on the cracking properties of stainless steels using actual tritium reservoir forgings instead of the experimental forgings of past programs. The properties measured should be more representative of actual reservoir properties because the microstructure of the specimens tested will be more like that of the tritium reservoirs. The programs are designed to measure the effects of key forging variables on tritium compatibility and include three stainless steels, multiple yield strengths, and four different forging processes. The effects on fracture toughness of hydrogen and crack orientation were measured for type 316L forgings. In addition, hydrogen effects on toughness were measured for Type 304L block forgings having two different yield strengths. Finally, fracture toughness properties of type 304L

  7. HaploForge: A Comprehensive Pedigree Drawing and Haplotype Visualisation Web Application.

    Science.gov (United States)

    Tekman, Mehmet; Medlar, Alan; Mozere, Monika; Kleta, Robert; Stanescu, Horia

    2017-08-14

    Haplotype reconstruction is an important tool for understanding the aetiology of human disease. Haplotyping infers the most likely phase of observed genotypes conditional on constraints imposed by the genotypes of other pedigree members. The results of haplotype reconstruction, when visualised appropriately, show which alleles are identical by descent despite the presence of untyped individuals. When used in concert with linkage analysis, haplotyping can help delineate a locus of interest and provide a succinct explanation for the transmission of the trait locus. Unfortunately, the design choices made by existing haplotype visualisation programs do not scale to large numbers of markers. Indeed, following haplotypes from generation to generation requires excessive scrolling back and forth. In addition, the most widely-used program for haplotype visualisation produces inconsistent recombination artefacts for the X chromosome. To resolve these issues, we developed HaploForge, a novel web application for haplotype visualisation and pedigree drawing. HaploForge takes advantage of HTML5 to be fast, portable and avoid the need for local installation. It can accurately visualise autosomal and X-linked haplotypes from both outbred and consanguineous pedigrees. Haplotypes are coloured based on identity by descent using a novel A* search algorithm and we provide a flexible viewing mode to aid visual inspection. HaploForge can currently process haplotype reconstruction output from Allegro, GeneHunter, Merlin and Simwalk. HaploForge is licensed under GPLv3 and is hosted and maintained via GitHub. Supplementary data is available from Bioinformatics online.

  8. Decomposition of forging die for high speed machining

    CERN Document Server

    Tapie, Laurent

    2009-01-01

    Today's forging die manufacturing process must be adapted to several evolutions in machining process generation: CAD/CAM models, CAM software solutions and High Speed Machining (HSM). In this context, the adequacy between die shape and HSM process is in the core of machining preparation and process planning approaches. This paper deals with an original approach of machining preparation integrating this adequacy in the main tasks carried out. In this approach, the design of the machining process is based on two levels of decomposition of the geometrical model of a given die with respect to HSM cutting conditions (cutting speed and feed rate) and technological constrains (tool selection, features accessibility). This decomposition assists machining assistant to generate an HSM process. The result of this decomposition is the identification of machining features.

  9. Decomposition of forging dies for machining planning

    CERN Document Server

    Tapie, Laurent; Anselmetti, Bernard

    2009-01-01

    This paper will provide a method to decompose forging dies for machining planning in the case of high speed machining finishing operations. This method lies on a machining feature approach model presented in the following paper. The two main decomposition phases, called Basic Machining Features Extraction and Process Planning Generation, are presented. These two decomposition phases integrates machining resources models and expert machining knowledge to provide an outstanding process planning.

  10. Decomposition of forging dies for machining planning

    OpenAIRE

    Tapie, Laurent; Mawussi, Kwamiwi; Anselmetti, Bernard

    2009-01-01

    International audience; This paper will provide a method to decompose forging dies for machining planning in the case of high speed machining finishing operations. This method lies on a machining feature approach model presented in the following paper. The two main decomposition phases, called Basic Machining Features Extraction and Process Planning Generation, are presented. These two decomposition phases integrates machining resources models and expert machining knowledge to provide an outs...

  11. 3-D thermo-mechanical coupled FEM simulation of continuous hot rolling process of 60SiMnA spring steel bars and rods

    Institute of Scientific and Technical Information of China (English)

    Jiahe Ai; Huiju Gao; Tongchun Zhao; Xishan Xie; Yu Liu

    2004-01-01

    The 3-D thermo-mechanical coupled elasto-plastic finite element method (FEM) was used for the simulation of the twopass continuous hot rolling process of 60SiMnA spring steel bars and rods using MARC/AutoForge3.1 software. The simulated results visualize the metal flow and the dynamic evolutions of the strain, stress and temperature during the continuous hot rolling, especially inside the work-piece. It is shown that the non-uniform distributions of the strain, stress and temperature on the longitudinal and transverse sections are a distinct characteristic of the continuous hot rolling, which can be used as basic data for improving the tool design, predicting and controlling the micro-structural evolution of a bar and rod.

  12. Forging of Mg-alloys AZ31 and AZ80

    Energy Technology Data Exchange (ETDEWEB)

    Viehweger, B.; Karabet, A.; Duering, M. [Brandenburg University of Technology, Interdisciplinary Research Centre for Lightweight Materials ' ' Panta Rhei' ' , Konrad-Wachsmann-Allee 17, 03046 Cottbus (Germany); Schaeffer, L. [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

    2005-05-01

    Mg-wrought alloys recently became an engineer material of constantly increasing interest. The mechanical properties of extruded Mg-feedstock of the alloys AZ80 and AZ31 indicate their suitability for automotive applications in form of high-quality forgings. Therefore a detailed knowledge about the forming behaviour is of particular importance. In order to compare mechanical properties of available Mg-feedstock qualities compression tests at room temperature have been carried out by applying batches of AZ31- and AZ80-feedstock. Cylindrical specimens were made out of received continuously casted as well as extruded AZ31- and AZ80 - rods. A quantitative analysis of Mg-feedstock's microstructure has been carried out. The characterization of the deformability of applied Mg-feedstock under hot working conditions could be performed by means of uniaxial plain strain upsetting tests at temperatures between 300 and 450 C as well as logarithmic strain rates of 10{sup -1}, 1 and 10s{sup -1}. It is shown that the chosen parameter range ensures an enhanced deformability of continuously as well as extruded Mg-feedstock. The subsequently carried out determination of microstructural evolution could be related to obtained flow stress curves of applied batches of Mg-feedstock. Furthermore, FVM/FEM-systems have been employed in order to design a simplified geometry of heated forging dies suitable for forging tests. The tests have been carried out by means of a hydraulic press. During the tests their punch velocity has been varied between 1 and 40 mm/s. Hence numerically simulated results could be confirmed by practical tests. Exemplary forgings of a simplified shape were made out of all applied batches of Mg-feedstock. No remarkable failures have been detected. (Abstract Copyright [2005], Wiley Periodicals, Inc.) [German] Das Interesse an Mg-Knetlegierungen als Konstruktionswerkstoff fuer automobile Anwendung ist in juengster Zeit stark gewachsen. Daher ist eine detaillierte

  13. Influence of Forging on Static Pricing Scheme for Priority Services

    Institute of Scientific and Technical Information of China (English)

    LIU Ji-cheng; SHI Bing-xin; YANG Xue-nan; LI Bo

    2005-01-01

    The influence of ISP's ( internet service provider) forging on static pricing scheme for priority services is analyzed. If ISP is honest, besides the price, after users enter the network market, it can't affect the market; if it forges, it can change its utility. The economical analysis proves that forging is possible, when ISP gains more than its loss, ISP will take the action. In response to forging, users may adapt their traffic allocation vectors to maximize their net benefit. If users will submit more traffic or in higher priority service class, ISP gains from the behavior, if users will submit less traffic or even exits the market, ISP 's utility decrease. The market is completely different from before, forging changes the market. Several examples are presented to illustrate the results. At the same time, how the utility function and the willingness to pay affect forging is discussed.

  14. 行星齿轮精锻工艺分析与试验研究%Process analysis and experiment study on precision forging of planetary gear

    Institute of Scientific and Technical Information of China (English)

    闫红艳; 边翊; 彭冲; 刘桂华; 蒋智; 马晓晖

    2011-01-01

    According to indicator for gear accuracy testing, the questions that need pay attention to during accuracy controlling was put forward, and corresponding solution for each question was proposed. Based on systemic analysis of the problems such as elastic deformation of tooth profile, tooth surface and die life during the hot forging and cold forging process, the hot forging-cold finishing process was determined and the design of precision forging and hot forging dies were finished. The experiment study on the hot precision forging process for different blank dimensions and upsetting ratios was carried out, and the impact of blank and upsetting ratio to tooth file was analyzed. The result shows that, when billet diameter is less than the diameter at the small end of the gear and upset ratio is 1.5, the tooth profile and tooth head of the hot forging gear are filled well, and the tooth profile is full and accurate. After cleaning the iron oxide skin thoroughly, the surface quality of the forging is good.%根据齿轮精度检验的指标,提出了精度控制需要注意的问题,并针对每个问题提出解决办法.在系统分析热精锻和冷锻成形过程中齿形、齿面、弹性变形及模具寿命等问题的基础上,确定了热精锻—冷精整工艺流程,完成了精锻件及热精锻模的设计.对不同坯料尺寸和镦粗比的热精锻工艺过程进行了试验研究,分析了坯料和镦粗比对齿形充满的影响.研究结果表明,采用直径小于分锥角小端直径的坯料,选定镦粗比1.5进行热锻成形,锻造的热精锻齿轮齿形、齿顶充满效果较好,冷精整后的齿形饱满准确,在对氧化铁皮进行彻底清理后,锻件表面质量良好.

  15. 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.

  16. 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.

  17. The Development Of Heating Curves For Open Die Forging Of Heavy Parts

    Directory of Open Access Journals (Sweden)

    Gołdasz A.

    2015-09-01

    Full Text Available The study presents the findings of research on developing heating curves of heavy parts for the open die forging process. Hot ingots are heated in a chamber furnace. The heating process of 10, 30, 50 Mg ingots was analyzed. In addition, bearing in mind their high susceptibility to fracture, the ingots were sorted into 3 heating groups, for which the initial furnace temperature was specified. The calculations were performed with self developed software Wlewek utilizing the finite element method for the temperature, stress and strain field computations.

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

    DEFF Research Database (Denmark)

    Bay, Niels

    2011-01-01

    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....... 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...

  19. A comparative machining study of diamond-coated tools made by plasma torch, microwave, and hot filament techniques

    Indian Academy of Sciences (India)

    C E Bauer; A Inspektor; E J Oles

    2003-10-01

    An effective metal-cutting tool is usually a combination of a hard coating and a tough substrate. The successful deposition of diamond outside its thermodynamic stability range has stimulated the development of a new class of cutting tools: those with diamond-coated inserts of any desired style and edge geometry. The successful implementation of diamond coatings also expedited similar research in the deposition of cubic boron nitride. This paper presents superhard coating tools, with emphasis on diamond-coated WC–Co tools, the corresponding deposition of technologies and the foreseen metal-cutting applications.

  20. COMPUTER MODELING IN DEFORM-3D FOR ANALYSIS OF PLASTIC FLOW IN HIGH-SPEED HOT EXTRUSION OF BIMETALLIC FORMATIVE PARTS OF DIE TOOLING

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2015-01-01

    Full Text Available The modern development of industrial production is closely connected with the use of science-based and high technologies to ensure competitiveness of the manufactured products on the world market. There is also much tension around an energy- and resource saving problem which can be solved while introducing new technological processes and  creation of new materials that provide productivity increase through automation and improvement of tool life. Development and implementation of such technologies are rather often considered as time-consuming processes  which are connected with complex calculations and experimental investigations. Implementation of a simulation modelling for materials processing using modern software products serves an alternative to experimental and theoretical methods of research.The aim of this paper is to compare experimental results while obtaining bimetallic samples of a forming tool through the method of speed hot extrusion and the results obtained with the help of computer simulation using DEFORM-3D package and a finite element method. Comparative analysis of plastic flow of real and model samples has shown that the obtained models provide high-quality and reliable picture of plastic flow during high-speed hot extrusion. Modeling in DEFORM-3D make it possible to eliminate complex calculations and significantly reduce a number of experimental studies while developing new technological processes.

  1. European Community research on forging of magnesium alloys (MagForge): state of affairs

    NARCIS (Netherlands)

    Sillekens, W.H.; Chevaleyre, F.; Gantar, G.

    2009-01-01

    While the interest in wrought magnesium applications is growing, forging of magnesium alloys in Europe and beyond is still restricted to a few specialized companies that operate for niche markets. Technical matters that relate to this are underdeveloped mechanical properties of available feedstock m

  2. European Community research on forging of magnesium alloys (MagForge): state of affairs

    NARCIS (Netherlands)

    Sillekens, W.H.; Chevaleyre, F.; Gantar, G.

    2009-01-01

    While the interest in wrought magnesium applications is growing, forging of magnesium alloys in Europe and beyond is still restricted to a few specialized companies that operate for niche markets. Technical matters that relate to this are underdeveloped mechanical properties of available feedstock

  3. Functional properties of surface layers of X38CrMoV5-3 hot work tool steel alloyed with HPDL laser

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2007-10-01

    Full Text Available Purpose: Improvement of functional properties alloyed of hot work tool steel surface layers is one of the goals of this paper.Design/methodology/approach: The material used for investigation was the hot work tool steel X38CrMoV5-3. Remelting and alloying of surface layers were made using the HPDL high power diode laser Rofin DL 020 in the laser power range of 1.2-2.3 kW. The carbide powders were applied on specimens prepared and degreased in this way; the powder was mixed with the sodium glass as inorganic binder in proportion of 30% binder and 70% powder. Paste coating 0.5 mm thick was put down in each case.Findings: The hardness changes of the surface layers obtained by remelting and alloying with carbides using the high power diode laser are accompanied with the improved tribological properties compared to the conventionally heat treated steel. The highest abrasion wear resistance, more than 2.5 times higher than that of the base material, was revealed in case the steel alloyed with vanadium carbide.Research limitations/implications: These advantages are the result of features unique to the HPDL, such as: shorter wavelength (thus better beam absorption for most metallic materials, and smaller absorption length and better temporal beam stability (due to beam integration compared to Nd:YAG and CO2 lasers. HPDL materials processing is, therefore, expected to produce better quality and more consistent and repeatable results for applications requiring beam spot sizes larger than 0.5mm diameter. One of the issues of concern in the practical applications of the lasers in materials processing for mass production is the repeatability.Practical implications: The research results indicate to the feasibility and purposefulness of the practical use of remelting and alloying with the ceramic particles using the high power diode laser for manufacturing and regeneration of various tools from the X38CrMoV5-3 hot-work tool steel.Originality/value: The laser

  4. Application of ICH Q9 Quality Risk Management Tools for Advanced Development of Hot Melt Coated Multiparticulate Systems.

    Science.gov (United States)

    Stocker, Elena; Becker, Karin; Hate, Siddhi; Hohl, Roland; Schiemenz, Wolfgang; Sacher, Stephan; Zimmer, Andreas; Salar-Behzadi, Sharareh

    2017-01-01

    This study aimed to apply quality risk management based on the The International Conference on Harmonisation guideline Q9 for the early development stage of hot melt coated multiparticulate systems for oral administration. N-acetylcysteine crystals were coated with a formulation composing tripalmitin and polysorbate 65. The critical quality attributes (CQAs) were initially prioritized using failure mode and effects analysis. The CQAs of the coated material were defined as particle size, taste-masking efficiency, and immediate release profile. The hot melt coated process was characterized via a flowchart, based on the identified potential critical process parameters (CPPs) and their impact on the CQAs. These CPPs were prioritized using a process failure mode, effects, and criticality analysis and their critical impact on the CQAs was experimentally confirmed using a statistical design of experiments. Spray rate, atomization air pressure, and air flow rate were identified as CPPs. Coating amount and content of polysorbate 65 in the coating formulation were identified as critical material attributes. A hazard and critical control points analysis was applied to define control strategies at the critical process points. A fault tree analysis evaluated causes for potential process failures. We successfully demonstrated that a standardized quality risk management approach optimizes the product development sustainability and supports the regulatory aspects.

  5. 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 ...

  6. 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.

  7. Numerical Analysis on Rotary Forging Mechanism of a Flange

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A numerical simulation on the rotary forging process of a flange is conducted by three-dimensional rigid-plastic finite element method. The states of stress and strain rate in the workpiece are analyzed and the forging mechanism of the flange is revealed. Moreover, the influence of the die configuration on the material flow is also analyzed.

  8. 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....

  9. Hot Money, Hot Potato

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    International hot money flowing into Chinese capital markets has caught the attention of Chinese watchdogs The Chinese are not the only ones feasting on the thriving property and stock markets. Apparently, these markets are the targets of international h

  10. Application of multi-grid method on the simulation of incremental forging processes

    Science.gov (United States)

    Ramadan, Mohamad; Khaled, Mahmoud; Fourment, Lionel

    2016-10-01

    Numerical simulation becomes essential in manufacturing large part by incremental forging processes. It is a splendid tool allowing to show physical phenomena however behind the scenes, an expensive bill should be paid, that is the computational time. That is why many techniques are developed to decrease the computational time of numerical simulation. Multi-Grid method is a numerical procedure that permits to reduce computational time of numerical calculation by performing the resolution of the system of equations on several mesh of decreasing size which allows to smooth faster the low frequency of the solution as well as its high frequency. In this paper a Multi-Grid method is applied to cogging process in the software Forge 3. The study is carried out using increasing number of degrees of freedom. The results shows that calculation time is divide by two for a mesh of 39,000 nodes. The method is promising especially if coupled with Multi-Mesh method.

  11. 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)

  12. Effect of Nano-Scale and Micro-Scale Yttria Reinforcement on Powder Forged AA-7075 Composites

    Science.gov (United States)

    Joshi, Tilak C.; Prakash, U.; Dabhade, Vikram V.

    2016-05-01

    The present investigation deals with the development of AA-7075 metal matrix composites reinforced with nano yttria particles (0.1 to 3 vol.%) and micron yttria particles (1 to 15 vol.%) by powder forging. Matrix powders (AA-7075) and reinforcement powders (yttria) were blended, cold compacted, sintered under pure nitrogen, and finally hot forged in a closed floating die. The hot forged samples were artificially age hardened at 121 °C for various time durations to determine the peak aging time. The mechanical properties in the peak-aged condition as well as density and microstructure were determined and correlated with the reinforcement size and content. The nano composites exhibited a well-densified structure as well as better hardness and tensile/compressive strength as compared to micro-scale composites. The mechanical properties in nano-scale composites peaked at 0.5 vol.% yttria addition while for micro-scale composites these properties peaked at 5 vol.% yttria addition.

  13. Regression Modeling Of Cutting Parameters' Effect To Cutting Forces And Hole Surface Qualities In Drilling Of Dievar Hot Work Tool Steel

    Directory of Open Access Journals (Sweden)

    İskender Özkul

    2013-01-01

    Full Text Available In this study, cutting moments, surface roughness, dimensional accuracy and circularity deviation values were investigated during drilling on Dievar degree of hot work tool steels with various drill bits. The experiments, was completed with Ø16 mm diameter uncoated carbide drill bits and TiAlN coated self-reamed carbide drill bits using coolant fluid on vertical machining center. In experiments, feed rate 0,16 mm/rev and the cutting speed 36, 40, 44, 48 m/min rates were used. The results were modeled by the method of linear regression and polynomial regression curve. Then they were compared with values equal significance. At the same time by analysis of variance, the cutting speed and drill type were investigated on the results of axial feed force, cutting torque, surface roughness, dimensional accuracy and circularity the deviation.

  14. INFLUENCE OF COOLING RATE DURING QUENCHING ON IMPACT TOUGHNESS OF A HOT-WORK TOOL STEEL AT AMBIENT TEMPERATURE AND AT 200 °C

    Directory of Open Access Journals (Sweden)

    Henrik Jesperson

    2013-05-01

    Full Text Available Gross cracking of die-casting dies with inferior toughness sometimes occurs through too low preheating temperature and/or too slow cooling during quenching. This study aimed to clarify the influence of cooling rate on the toughness of the hot-work tool steel grade Uddeholm Vidar Superior at ambient temperature and at 200 °C, a typical preheating temperature for aluminium die-casting dies. Toughness was measured through instrumented Charpy V-notch impact testing. The decrease in energy absorption with increasing cooling time between 800°C and 500°C both at both ambient temperature and 200 °C was pronounced. At ambient temperature, the decrease in total energy was a consequence of a decrease in initiation energy whereas, at 200 °C, the decrease in total energy was due to a decrease in propagation energy.

  15. The Hot Spot Analysis: Utilization as Customized Management Tool towards Sustainable Value Chains of Companies in the Food Sector

    Directory of Open Access Journals (Sweden)

    H. Rohn

    2014-12-01

    Full Text Available The food and agricultural sector will face numerous challenges in the next decades, arising from changing global production and consumption patterns, which currently go along with high resource use, causing ecological and socio-economic impacts. The aim of this paper is to illustrate and evaluate the practical applicability of the Hot Spot Analysis methodology in the context of supply chain management in companies. The HSA is a method to identify social and ecological problems along the entire life cycle of a product. Special emphasis is put on a customized implementation in the value chain beef of McDonald’s Germany. The HSA of McDonald’s beef value chain shows that the main ecological problems arise in the phase of raw material extraction, whereas the main social problems can be identified in the phase of slaughtering. Finally, the paper shows potentials and shortcomings of such a customized application and how the results can be implemented in the sustainability management of a company.

  16. Consolidation of nanostructured metal powders by rapid forging: Processing, modeling, and subsequent mechanical behavior

    Science.gov (United States)

    Shaik, G. R.; Milligan, W. W.

    1997-03-01

    Fe-10Cu powders containing 20-nm grains were produced by attritor milling of elemental powders in argon. A rapid powder forging technique was developed to consolidate the powders into fully dense compacts while maintaining nanoscale grain sizes. Grain growth during the consolidation was controlled by reducing the time of exposure at elevated temperature to a few minutes or less, a technique which is applicable to all materials and does not necessitate the addition of dispersoids. This was achieved by heating green compacts quickly using an induction heater, and then forging and rapidly cooling them back to room temperature. Forging was conducted in a protective argon atmosphere to limit contamination. Fully dense compacts were produced at relatively low temperatures, mainly due to the accelerated creep rates exhibited by the nanostructures. Transmission electron microscopy and X-ray diffraction analysis found an average grain size of 45 nm in the fully dense samples forged at 530°C. Indications are that finer grain sizes should be attainable by using slightly lower temperatures and higher pressures. The success of the technique (compared to hot-isostatic pressing (“hipping”)) is due to both reducing time at elevated temperatures and applying relatively high pressures. Microhardness tests revealed a significant strengthening effect due to grain size refinement, following a Hall-Petch relation. Compression testing at room temperature showed no strain hardening during plastic deformation, which occurred by shear banding. High strengths, up to 1800 MPa, were obtained at room temperature. Compression testing at 575°C revealed a significant strain rate dependence of mechanical behavior and also the possibility of superplastic behavior. Power-law creep was observed at 575°C, with very high steady-state creep rates on the order of 50 pct/s at 230 MPa. The consolidation process was successfully modeled by slightly modifying and applying the Arzt, Ashby, and

  17. 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.

  18. Non-destructive Testing of Forged Metallic Materials by Active Infrared Thermography

    Science.gov (United States)

    Maillard, S.; Cadith, J.; Bouteille, P.; Legros, G.; Bodnar, J. L.; Detalle, V.

    2012-11-01

    Nowadays, infrared thermography is considered as the reference method in many applications such as safety, the inspection of electric installations, or the inspection of buildings' heat insulation. In recent years, the evolution of both material and data-processing tools also allows the development of thermography as a real non-destructive testing method. Thus, by subjecting the element to be inspected to an external excitation and by analyzing the propagation of heat in the examined zone, it is possible to highlight surface or subsurface defects such as cracks, delaminations, or corrosion. One speaks then about active infrared thermography. In this study, some results obtained during the collective studies carried out by CETIM and the University of Reims for the forging industry are presented. Various experimental possibilities offered by active thermography are presented and the interest in this method in comparison with the traditional non-destructive testing methods (penetrant testing and magnetic particle inspection) is discussed. For example, comparative results on a forged cracked hub, a steering joint, and a threaded rod are presented. They highlight the interest of infrared thermography stimulated by induction for forged parts.

  19. Medium carbon vanadium micro alloyed steels for drop forging

    Energy Technology Data Exchange (ETDEWEB)

    Jeszensky, Gabor; Plaut, Ronald Lesley

    1992-12-31

    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) 17 refs., 19 figs., 5 tabs.

  20. 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

  1. Development of low-friction and wear-resistant surfaces for low-cost Al hot stamping tools

    Directory of Open Access Journals (Sweden)

    Dong Y.

    2015-01-01

    Full Text Available In this study, advanced surfaces and coatings have been developed using plasma thermochemical treatment, PVD coating, electroless Ni-BN plating and duplex surface engineering to produce low-friction and wear-resistant surfaces for cast iron stamping tools. Their microstructural and nano-mechanical properties were systematically analysed and the tribological behaviour of these new surfaces and coatings were evaluated. The experimental results have shown that under dry sliding condition, the tribological behaviour of aluminium differed great from that of steel regardless of the counterpart material. Highly reactive aluminium had a strong tendency to solder with tool surfaces during dry sliding. However, the lubricity of gray cast irons can be significantly improved by Ni-BN and DLC coatings. The coefficient of friction reduced from about 0.5 for untreated cast irons to about 0.2 sliding against aluminium. Duplex treatment combining plasma nitrocarburising with low-friction coatings showed superior durability than both DLC and Ni-BN coatings.

  2. Influence of Hot Rolling on Cube Texture of Ni Substrate for Coated Conductor

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Pure Ni and Ni alloy tapes with sharp cube texture and low-angle grain boundaries prepared by thennomechanical process were extensively used as substrates for coated conductor. The thermomechanical process usually includes hot forging and cold rolling. In this study, a hot-rolling process between hot forging and cold rolling was induced. The influence of hot rolling on the cube texture of pure Ni was discussed. Sharp cube texture on pure Ni was obtained by suitable hot rolling, cold rolling, and recrystallization treatment. This deformation texture of tape was studied using orientation distribution function (ODF). Orientation mapping, content of the cube texture, and grain boundary distribution were performed using an EBSD system mounted on LEO-1450 SEM. The results show that the substrates that are hot rolled have a sharp cube texture and low-angle grain boundaries.

  3. Analysis and control on forging cracks of steel 0 Cr17 Ni4 Cu4 Nb%0 Cr17 Ni4 Cu4 Nb钢锻造裂纹分析与控制

    Institute of Scientific and Technical Information of China (English)

    郎荣兴; 李贵全; 殷春云

    2016-01-01

    For raw materials and forging technology of stainless steel 0Cr17Ni4Cu4Nb, it was found that the main reason for cracks pro-duced in forging was the excessive amounts of the delta ferrite in material internal microstructure. When the content of delta ferrite excee-ded a certain amount, the forging plasticity of material significantly decreased and the deformation resistance increased. Once deformation gradually increased to a certain amount, the cracks appeared, and became more serious with the increase of deformation. Research results show that check and control the content of delta ferrite in raw materials before using to ensure that the materials still have good plasticity in the hot working process and the ferrite content is less than 20% and meets or above the standard of F7 level of CB/T 1209—1992. At the same time roughness of the blank must achieve above Ra1. 6μm-Ra0. 8μm and the forging tools should be preheated and the forging de-formation of each heat should be strictly controlled to satisfy the requirement of design and quality of forgings.%针对0Cr17Ni4Cu4Nb不锈钢锻造生产过程中产生的锻造裂纹,对原材料和锻造工艺进行分析发现,产生裂纹的主要原因是由于材料内部组织中的δ铁素体含量超过一定量时,会极大地降低材料的锻造塑性,使得变形抗力增大;当变形量逐渐增加到一定量时,裂纹开始出现,并且随着变形量的增加裂纹越来越严重。研究结果表明,在使用该材料时,需要对原材料进行铁素体含量检查并加以控制,铁素体含量要求<20%,符合CB/T 1209—1992 F7级以上标准,保证该材料良好的热加工工艺塑性;毛坯粗糙度要求达到Ra=1.6~0.8μm以上,预热锻造工具,严格控制每一火次的锻造变形量,以满足锻件的设计和质量要求。

  4. Critical current densities in Bi-2223 sinter forgings.

    Energy Technology Data Exchange (ETDEWEB)

    Balachandran, U.; Fisher, B. L.; Goretta, K. C.; Harris, N. C.; Murayama, N.

    1999-07-23

    (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Bi-2223) bars, prepared by sinter forging, exhibited good phase purity and strong textures with the c axes of the Bi-2223 grains parallel to the forging direction. The initial zero-field critical current density (J{sub c}) of the bars was 10{sup 3} A/cm{sup 2}, but because the forged bars were uncoated, this value decreased with repeated thermal cycling. J{sub c} as a function of applied magnetic field magnitude and direction roughly followed the dependencies exhibited by Ag-sheathed Bi-2223 tapes, but the forged bars were more strongly dependent on field strength and less strongly dependent on field angle.

  5. Valley Forge National Historical Park Tract and Boundary Data

    Data.gov (United States)

    National Park Service, Department of the Interior — This is an ESRI polygon shapefile of tracts for Valley Forge NHP (VAFO). Tracts shown on inset maps A, B, and C were spatially adjusted (i.e., rubbersheeted) to...

  6. Total quality management of forged products through finite element simulation

    Science.gov (United States)

    Chandra, U.; Rachakonda, S.; Chandrasekharan, S.

    The paper reviews the entire thermo-mechanical history experienced by a complex shaped, high strength forged part during all stages of its manufacturing process, i.e. forging, heat treatment, and machining. It examines the current practice of selecting the process parameters using finite element simulation of forging and quenching operations on an individual basis. Some recent work related to the simulation of aging and machining operations is summarized. The capabilities of several well-known finite element codes for these individual simulations are compared. Then, an integrated simulation approach is presented which will permit the optimization of process parameters for all operations, as opposed to a single operation. This approach will ensure a total quality management of forged products by avoiding costly problems which, under the current practice, are detected only at the end of the manufacturing cycle, i.e. after final machining.

  7. The State of the Art in Cold Forging Lubrication

    DEFF Research Database (Denmark)

    Bay, Niels

    1994-01-01

    the conversion coatings are based on zinc phosphates but different requirements to the coating properties have to be met in different cold forging operations. This is obtained by adopting different oxidants leading to different composition, layer thickness and morphology of the conversion coatings. Concerning...... 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...... aluminium unalloyed and softer alloys like the AA 1000, 3000 and 6000 series can be cold forged with either grease, oil or zinc stearate whereas the harder alloys from series AA 2000, 5000 and 7000 require a conversion coating to carry the lubricant. Three different types of conversion coating are described...

  8. Microstructure optimization design methods of the forging process and applications

    Institute of Scientific and Technical Information of China (English)

    WANG Guangchun; ZHAO Guoqun; GUAN Jing

    2007-01-01

    A microstructure optimization design method of the forging process is proposed. The optimization goal is the fine grain size and homogeneous grain distribution. The optimization object is the forging process parameters and the shape of the preform die. The grain size sub-objective function, the forgings shape sub-objective function and the whole objective function including the shape and the grain size are established, espectively. The detailed optimization steps are given. The microstructure optimization program is developed using the micro-genetic algorithm and the finite element method. Then, the upsetting process of the cylindrical billet is analyzed using a self-developed program. The forging parameters and the shape of preform die of the upsetting process are optimized respectively. The fine size and homogenous distribution of the grain can be achieved by controlling the shape of the preform die and improving the friction condition.

  9. Optimization of Forging Process of Intermediate Shaft%中间轴锻造工艺优化

    Institute of Scientific and Technical Information of China (English)

    胡晓琦; 李晓峰; 曹志远

    2013-01-01

    When producing the large asymmetrical flange etc hollow shaft parts with the conventional open die forging process, the flange side of hollow shaft part is very likely irregular offset and concave in center hole, which may affect the size of final forging and reduces the utilization rate of ingot. In this paper, a new forging process of intermediate shaft based on existing auxiliary tools is described and the confining of flange side center, end face deflection and offset irregularity of flange side were effectively improved and forging part with good size was obtained finally.%针对传统自由锻造工艺生产中间轴等非对称大法兰空心轴类件时,容易在法兰侧出现较为严重的偏摆和内孔凹心现象,影响最终锻件尺寸,坯料利用率低的缺点。介绍一种改进锻造工艺,在利用现有附具基础上,可有效克服中间轴锻件两端面内孔凹心、法兰长短面及其端面偏摆等技术难点,最终得到满足尺寸要求的锻件。

  10. Mechanical properties of the as-forged and the forged-and-milled steels for reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Yoon, Ji Hyun; Kim, Joo Hak; Oh, Yong Jun; Hong, Jun Hwa [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-04-01

    The mechanical properties of the as-forged and the forged and milled SA508-Gr.3 reactor pressure vessel steels were evaluated. The full Charpy impact curves obtained for four different locations in test materials. The various data including yield strengths, tensile strengths, elongations were obtained from the tensile strengths, elongations were obtained from the tensile test results for two locations in test materials. The detailed test results were integrated and analysed in this report. 6 refs., 7 figs., 5 tabs. (Author)

  11. RIGID-PLASTIC MECHANICAL MODEL FOR THE FORGING METHOD WITH HORIZONTAL V-SHAPED ANVIL

    Institute of Scientific and Technical Information of China (English)

    LIU Zhubai; NI Liyong; LIU Guohui; ZHANG Yongjun; ZHU Wenbo

    2006-01-01

    In order to decrease the anisotropy of mechanical properties, the rigid-plastic mechanical model for the forging method with horizontal V-shaped anvil is presented. The forging method,through the change of anvils shape, is able to control fibrous tissue direction, to improve the anisotropy of mechanical properties of axial forgings, to realize uniform forging. Therefore, the forging method can overcome the defect that conventional forging methods produce. The mechanism of the forging method with horizontal V-shaped anvil and the process of metal deformation are analyzed. The agreement of theoretical analysis with experimental study verifies the fact that the forging method with horizontal V-shaped anvil can control effectively the mechanical properties of axial forgings.

  12. Experimental Investigation and Numerical Simulation of the Grain Size Evolution during Isothermal Forging of a TC6 Alloy

    Institute of Scientific and Technical Information of China (English)

    Miaoquan LI; Shankun XUE; Aiming XIONG; Shenghui CHEN

    2005-01-01

    Hot compression was conducted at a Thermecmaster-Z simulator, at deformation temperatures of 800~1040℃, with strain rates of 0.001~50 s-1 and height reduction of 50%. Grain size of the prior α phase was measured with a Leica LABOR-LUX12MFS/ST microscope to which QUANTIMET 500 software for image analysis for quantitative metallography was linked. According to the present experimental data, a constitutive relationship for a TC6 alloy and a model for grain size of the prior α phase were established based on the Arrhenius' equation and the Yada's equation,respectively. By finite element (FE) simulation, deformation distribution was determined for isothermal forging of a TC6 aerofoil blade at temperatures of 860~940℃ and hammer velocities of 9~3000.0 mm/min. Meanwhile, the grain size of the prior α phase is simulated during isothermal forging of the TC6 aerofoil blade, by combining FE outputs with the present grain size model. The present results illustrate the grain size and its distribution in the prior α phase during the isothermal forging of the TC6 aerofoil blade. The simulated results show that the height reduction, deformation temperature, and hammer velocity have significant effects on distribution of the equivalent strain and the grain size of the prior α phase.

  13. Atom probe study of the carbon distribution in a hardened martensitic hot-work tool steel X38CrMoV5-1.

    Science.gov (United States)

    Lerchbacher, Christoph; Zinner, Silvia; Leitner, Harald

    2012-07-01

    The microstructure of the hardened common hot-work tool steel X38CrMoV5-1 has been characterized by atom probe tomography with the focus on the carbon distribution. Samples quenched with technically relevant cooling parameters λ from 0.1 (30 K/s) to 12 (0.25 K/s) have been investigated. The parameter λ is an industrially commonly used exponential cooling parameter, representing the cooling time from 800 to 500 °C in seconds divided with hundred. In all samples pronounced carbon segregation to dislocations and cluster formation could be observed after quenching. Carbon enriched interlath films with peak carbon levels of 6-10 at.%, which have been identified to be retained austenite by TEM, show a thickness increase with increasing λ. Therefore, the fraction of total carbon staying in the austenite grows. This carbon is not available for the tempering induced precipitation of secondary carbides in the bulk. Through all samples no segregation of any substitutional elements takes place. Charpy impact testing and fracture surface analysis of the hardened samples reveal the cooling rate induced microstructural distinctions.

  14. CHARACTERIZATION OF NEW TOOL STEEL FOR ALUMINUM EXTRUSION DIES

    Directory of Open Access Journals (Sweden)

    José Britti Bacalhau

    2014-06-01

    Full Text Available Aluminum extrusion dies are an important segment of application on industrial tools steels, which are manufactured in steels based on AISI H13 steel. The main properties of steels applied to extrusion dies are: wear resistance, impact resistance and tempering resistance. The present work discusses the characteristics of a newly developed hot work steel to be used on aluminum extrusion dies. The effects of Cr and Mo contents with respect to tempering resistance and the Al addition on the nitriding response have been evaluated. From forged steel bars, Charpy impact test and characterization via EPMA have been conducted. The proposed contents of Cr, Mo, and Al have attributed to the new VEX grade a much better tempering resistance than H13, as well as a deeper and harder nitrided layer. Due to the unique characteristics, this new steel provides an interesting alternative to the aluminum extrusion companies to increase their competitiveness.

  15. Mannes of Forging and Perspectives of Knuckle Joint Presses Modernization

    Directory of Open Access Journals (Sweden)

    A. A. Antsifirov

    2014-01-01

    Full Text Available The article raises an issue to enhance technological forging capabilities on the known knuckle joint presses. It provides an illustrated overview of main design types of presses with crank-knuckle, toggle-knuckle, and knuckle joint mechanisms. The article also shows the advantages of the modernization way and improvement just of the active press equipment in terms of quality-to-price ratio, for example, as compared to the similar new foreign press equipment.It gives an overview of features, which provide forging processes owing to kinetic energy accumulated with the moving parts of the known designs of the knuckle joint presses depending on the drive actuating mechanism. Focused attention is drawn to forging on the knuckle joint presses for a time of contact with a work piece to be comparable with the duration of the work piece deformation process on hydraulic forging hammers. This allows us to forge thin-wall products with process automation compared to the forging hammers.Analysis of accumulating processes of kinetic energy by the moving parts of the knuckle joint presses has shown that presses driven by hydraulic cylinders or two screw hydraulic cylinder are the most optimal for technological operations as evidenced by references to domestic and foreign invention certificates and patents. The article presents disadvantages of forging on presses with hydraulic or pneumatic drive. It is a dependence of the deformation force, caused, mainly, by a force of the drive cylinder. The article gives linear movement rate quantities of press moving members depending on the drives of the actuating mechanism. Based on the above analysis of the features to manufacture work pieces on the knuckle joint presses, the article gives the rationale for the relevance of forging in a short period of time, provided that the moving parts of the press accumulate the required kinetic energy. This can be achieved only through modernization and improvement of forging

  16. Blade Forging Design Based on the Secondary Development of UG%UG二次开发在叶片锻造中的应用

    Institute of Scientific and Technical Information of China (English)

    魏科; 谢崴; 王高潮

    2011-01-01

    综合运用UG表达式法及UG二次开发工具UG/Open API,UG/Open MenuScript,UG/Open UIStyler和Visual C++ 6.0,根据叶片锻件的加工原理,开发叶片模锻参数化设计系统。在该系统中,叶片锻件和锻模造型易于设计及修改。对提高叶片模具设计的效率、缩短模具开发周期具有较强的实用价值,同时也为后期的叶片模具制造和有限元数值模拟做好了强大的铺垫。%Combined with the method of UG expression and the tools of the UG secondary development including UG/ Open MenuScript, UG/Open UIStyler, UG/Open API and Visual C++ 6.0, blade die forging parametric design system was developed based on the blade forging process theory. In this system, the blade forging and die were easily designed and modified This method brings practical values for improving efficiency of blade forging die design and shortening the die development period, meanwhile, making a strong foundation for the following blade forging die manufacture and simulation by finite element method.

  17. Forces at the Main Mechanism of a Railbound Forging Manipulator

    Directory of Open Access Journals (Sweden)

    Florian Ion Tiberiu Petrescu

    2015-12-01

    Full Text Available 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 determine the driving forces of the main mechanism from such manipulator. Forces diagram 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. Hydraulic drives are with the lifting hydraulic cylinder, the buffer hydraulic cylinder and the leaning hydraulic cylinder, which are individually denoted by c1, c2 and c3. In this work considering that the kinematics is being solved it determines the forces of the mechanism. In the first place shall be calculated all external forces from the mechanism (The inertia forces, gravitational forces and the force of the weight of the cast part. Is then calculated all the forces from couplers. 

  18. Defect analysis of complex-shape aluminum alloy forging

    Institute of Scientific and Technical Information of China (English)

    SHAN De-bin; ZHANG Yan-qiu; WANG Yong; XU Fu-chang; XU Wen-chen; L(U) Yan

    2006-01-01

    The isothermal precision forging was applied for the purpose of forming aluminum alloy with complex shape. The complexity of forging is easy to lead to the occurrence of the defects, such as underfilling, folding, metal flow lines disturbance and fibre breaking. The reasons for the defects were analyzed on the basis of experiments and finite element method(FEM). The results show that the size of flash gutter bridge, the lubricating condition and the deformation process are the main factors influencing the filling qualities of complex-shape aluminum alloy forging. The folding defect is mainly caused by different velocities of filling cavities, fast flow of much metal in one direction and confluence of two or multi metal strands. Improper metal distribution in different regions can cause the flow lines disturbance and fast metal flow in one direction is also a cause of the flow lines disturbance According to the reasons, some measures were taken to improve the quality of the forged parts. These studies can contribute to offering some experiences in making process project and optimizing the process parameters for forging complex-shape aviation products.

  19. 自行车曲柄链轮双轮摆辗铆接装置的设计%Design of Double Roller Rotary Forging Riveting Device for Bicycle Crank Sprocket

    Institute of Scientific and Technical Information of China (English)

    白西平; 孙书华; 聂兰启

    2012-01-01

    通过对自行车曲柄链轮双轮摆辗过程及变形的分析,设计了双轮摆辗铆接工具,并对生产中出现的问题,提出了改进措施.经试用,铆接处比以前光滑、平整,而且在摆辗过程中,材料变形均匀,摆辗力大小一致.%Through the analysis of double roller rotary forging process and deformation for bicycle crank sprocket, double roller rotary forging riveting tool was designed. Aiming at the problems in the producing process,improving measures were introduced. After tryout, riveting region became more smooth and level, moreover, the material deformation is uniform and rotary forging force is the same size in the rotary forging process.

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Miyazawa, Takeshi; Murai, Etsuo [Kushiro National College of Technology, Dept. of Mechanical Engineering, Kushiro, Hokkaido (Japan)

    2002-10-01

    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)

  2. Basic rules for rheologic forging process of semisolid alloy

    Institute of Scientific and Technical Information of China (English)

    Shuming Xing; Lizhong Zhang; Jianbo Tan; Chuanlin Zheng; Hanwu Liu; Peng Zhang; Yunhui Du

    2004-01-01

    Semisolid mold forging is a major type of semisolid processing, which is different from neither traditional mold forging nor traditional permanent casting. However, processing defects are often seen in work pieces because of lacking available rules for the process design and control. Some basic rules for the process design and control, simply named the shortest flowing length, pressure filling and the minimum uplifting mold pressure, are advanced in the paper based on amount of researches and experiments. The equations to determine the major process parameters are given out such as the filling pressure, forming pressure and locking mold pressure for the process design and control. The rules and equations are experimentally proved available and applicable by several actual work pieces produced by the semisolid forging process.

  3. Isothermal forging of γ-TiAl based alloys

    Institute of Scientific and Technical Information of China (English)

    黄朝晖

    2003-01-01

    The true stress-strain curves and processing window of Ti-47Al-2Cr-1Nb were set up through thermal physical simulation.A method for refinement of the as-cast+ HIPped structure was submitted,which included twostep deformation with a short intermediate heat-treatment between double deformations.The break-down operation of the canned ingot was performed by the isothermal forging processing mentioned above.The refining mechanism is characterized as breaking and bending of the as-cast+HIPped lamellae,dynamic recrystallization,and static globularization.Thus,a uniform and refined billet microstructure is obtained for the final component by forging operation.The deformation of a model disc is accomplished by the subsequent single-step isothermal forging at 1 100-1 150℃ using a closed compression die.

  4. Research on Integrated Casting and Forging Process of Aluminum Automobile Wheel

    OpenAIRE

    Zhang, Qi; Cao, Miao; ZHANG, DAWEI; Zhang, Shuai; Sun, Jue

    2014-01-01

    Integrated casting and forging process (ICFP) is a new manufacturing method combining the advantages of both casting and forging. Aluminum structure parts, such as aluminum alloy automobile wheel, with complex shape and excellent mechanical properties can be produced by this process. The effects of different process parameters on the ICFP of the automobile wheel were simulated by Forge software. Microstructure of forging region and the nonforging region were studied by experiment. The results...

  5. Mechanical properties of forgings depending on the changes in shape and chemical composition of inclusions

    Directory of Open Access Journals (Sweden)

    O. Híreš

    2010-10-01

    Full Text Available The article deals with mechanical properties of forgings used for special technology in cannon barrels production. The forgings are treated by elctroslag remelting technology (ESR to enhance its plastic properties and yield point. Described experiments are focused on mechanical properties and metallurgical quality (microstructure of steels from which are the forgings made. The article includes microstructure photographs and description of inclusions located in examined steels. Experimental results compare forgings treated by ESR and next ones without ESR.

  6. [On the convergence between humankind and Nature to create tools].

    Science.gov (United States)

    Gaillot, Fernand; Lledo, Pierre-Marie

    2007-10-01

    The authors' purpose will be here to underline the continuity of the adaptative processes that make Homo sapiens, sometimes a brilliant inventor, sometimes a mere imitator, forging tools already conceived by Nature itself.

  7. Recycling of AZ31 Mg alloy with high purity Mg deposition layer by hot working (solid recycling)

    Energy Technology Data Exchange (ETDEWEB)

    Chino, Y.; Mabuchi, M. [Inst. for Structural and Engineering Materials, National Inst. of Advanced Industrial Science and Technology, Nagoya (Japan); Yamamoto, A.; Iwasaki, H.; Tsubakino, H. [Div. of Materials Science and Engineering, Graduate School of Himeji Inst. of Tech., Himeji (Japan)

    2003-07-01

    Solid recycling of AZ31 Mg alloy with vapor deposition coating layer of high purity Mg was evaluated. In the open die forging experiments, two AZ31 Mg alloy specimens with the pure Mg layer were sufficiently bonded by forging at 673 K. Furthermore, the Al and Zn of the AZ31 substrate diffused up to the center of the pure Mg layer. By the theoretical analysis, it is suggested that the grain boundary diffusion enhanced by grain refinement due to hot forging contributes to the solid state bonding of the specimens. Also, the solid recycled specimen was fabricated from the AZ31 Mg substrate with pure Mg layer by hot extrusion at 673 K. The solid recycled specimen showed almost the same tensile properties as the virgin extruded specimen. This is probably related not only to the grain boundary diffusion but also severe plastic deformation by hot extrusion. (orig.)

  8. Development of Functionally Graded Materials for Manufacturing Tools and Dies and Industrial Processing Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Lherbier, Louis, W.; Novotnak, David, J.; Herling, Darrell, R.; Sears, James, W.

    2009-03-23

    Hot forming processes such as forging, die casting and glass forming require tooling that is subjected to high temperatures during the manufacturing of components. Current tooling is adversely affected by prolonged exposure at high temperatures. Initial studies were conducted to determine the root cause of tool failures in a number of applications. Results show that tool failures vary and depend on the operating environment under which they are used. Major root cause failures include (1) thermal softening, (2) fatigue and (3) tool erosion, all of which are affected by process boundary conditions such as lubrication, cooling, process speed, etc. While thermal management is a key to addressing tooling failures, it was clear that new tooling materials with superior high temperature strength could provide improved manufacturing efficiencies. These efficiencies are based on the use of functionally graded materials (FGM), a new subset of hybrid tools with customizable properties that can be fabricated using advanced powder metallurgy manufacturing technologies. Modeling studies of the various hot forming processes helped identify the effect of key variables such as stress, temperature and cooling rate and aid in the selection of tooling materials for specific applications. To address the problem of high temperature strength, several advanced powder metallurgy nickel and cobalt based alloys were selected for evaluation. These materials were manufactured into tooling using two relatively new consolidation processes. One process involved laser powder deposition (LPD) and the second involved a solid state dynamic powder consolidation (SSDPC) process. These processes made possible functionally graded materials (FGM) that resulted in shaped tooling that was monolithic, bi-metallic or substrate coated. Manufacturing of tooling with these processes was determined to be robust and consistent for a variety of materials. Prototype and production testing of FGM tooling showed the

  9. 77 FR 14445 - Application for a License To Export Steel Forging

    Science.gov (United States)

    2012-03-09

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Application for a License To Export Steel Forging Pursuant to 10 CFR 110.70(b) ``Public Notice of... Spain. December 15, 2011 head steel head steel February 7, 2012 forging. forging will be XR175...

  10. The prediction of the evolution of grain size of land-gear forging during the die-forging process

    Directory of Open Access Journals (Sweden)

    Lin Gao

    2015-01-01

    Full Text Available The land-gear forgings are the most important structure parts, made of high strength steel 300M. Because of the bad service environment, the microstructure and performance of the part are very strict requirements. In this article the evolution of grain size during the die-forging process is predicted, the volume fraction of dynamic recrystallization, grain refinement and development of grain size in-homogeneity, and the affection of billet shape on the grain size distribution are analyzed. The simulated results show that the grain size differences on the different billet positions are very large at the deformation beginning. But in final forging stage, the difference of the average grain size is smaller. At some center zones of the part the maximum difference of grain size is bigger than 100 μm.

  11. 平锻机锻件缺陷分析及对策%Failure analysis and solution of forging parts manufactured by horizontal forging machine

    Institute of Scientific and Technical Information of China (English)

    张国杰

    2013-01-01

    Taking the 1250T horizontal forging machine as an example, the process characteristics of this machine have been introduced in the text. The failures like poor straightness of rod, pad injury, folding and mismatch of tool in the daily production have been analyzed and the solution has been put forward.%结合公司1250t平锻机,介绍此种设备生产锻件工艺特点,并对日常生产中遇到的杆部直线度超差、垫伤、折叠及错模等锻件缺陷进行分析并提出解决办法.

  12. HOT 2012

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen...

  13. 大盘毛坯在80000kN螺旋压力机生产线上的锻造工艺%Forging technology of big disk-type blank on 80000kN screw press line

    Institute of Scientific and Technical Information of China (English)

    戴东海

    2011-01-01

    介绍了80000kN螺旋压力机生产线的设备配置情况,通过对大盘锻件进行工艺分析提出了锻造工艺方案,设计了终锻模、切边模、热校正模等工装,并对大盘锻件生产流程进行了探讨.%The typical configuration of an 80000kN screw press production line has been introduced. By process analysis of big disk-type forgings, the jigs including finish-forging die, trimming die and hot straightening die have been designed. The production process of the big disk-type forgings has been discussed.

  14. A Simplified Inverse Approach for the Simulation of Axi-Symmetrical Cold Forging Process

    Science.gov (United States)

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

    2011-01-01

    This paper presents the formulation of an axi-symmetric element based on an efficient method called "Inverse Approach" (I.A.) for the numerical modeling of cold forging process. In contrast to the classical incremental methods, the Inverse Approach exploits the known shape of the final part and executes the calculation from the final part to the initial billet. The assumptions of the proportional loading and the simplified tool actions make the I.A. calculation very fast. The metal's incompressibility is ensured by the penalty method. The comparison with ABAQUS® and FORGE® shows the efficiency and limitations of the I.A. This simplified method will be a good tool for the preliminary preform design.

  15. Crystalline gamma-Al2O3 physical vapour deposition-coating for steel thixoforging tools.

    Science.gov (United States)

    Bobzin, K; Hirt, G; Bagcivan, N; Khizhnyakova, L; Ewering, M

    2011-10-01

    The process of thixoforming, which has been part of many researches during the last decades, combines the advantages of forging and casting for the shaping of metallic components. But due to the high temperatures of semi-solid steel alloys high demands on the tools are requested. To resists the thermal and mechanical loads (wear, friction, thermal and thermomechanical fatigue) protecting thin films are necessary. In this regard crystalline gamma-Al2O3 deposited via Physical Vapour Deposition (PVD) is a promising candidate: It exhibits high thermal stability, high oxidation resistance and high hot hardness. In the present work the application of a (Ti, Al)N/gamma-Al2O3 coating deposited by means of Magnetron Sputter Ion Plating in an industrial coating unit is presented. The coating was analysed by means of Rockwell test, nanoindentation, and Scanning Electron Microscopy (SEM). The coated tool was tested in thixoforging experiments with steel grade X210CrW12 (AlSI D6). The surface of the coated dies was examined with Scanning Electron Microscope (SEM) after 22, 42, 90 and 170 forging cycles.

  16. THREE-DIMENSIONAL FINITE-ELEMENT SIMULATION OF STRETCHING TECHNOLOGICAL PARAMETERS bt/h AND bb/h OF HEAVY FORGINGS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A three-dimensional finite-element simulation of stretching technological parameters of heavy forgings is performed by using ANSYS program. The law of internal stress distribution with different bt/h (tool width ratio) and different bb/h (blank width ratio) is studied. Consequently, the critical tool width ratio( bt/h )cr and blank width ratio( bb/h )cr leading no bi-axial tension are obtained. It lays a credible foundation for designing reasonable stretching technology.

  17. Roll forging die design based on UG secondary development%UG二次开发在辊锻模具设计中的应用

    Institute of Scientific and Technical Information of China (English)

    魏科; 王高潮; 李宁; 夏春林

    2011-01-01

    综合运用UG表达式法及UG二次开发工具UG/Open API、UG/0pen MenuScript、UG/Open UIStyler和Visual C++6.0,根据汽车前轴锻件的加工原理,开发了汽车前轴精制坯辊锻系统.在该系统中,前轴辊锻件和辊锻模参数化造型易于设计及修改,任何汽车前轴设计人员都能够方便的操作.该系统对提高汽车前轴辊锻模具设计的效率、缩短模具开发周期具有较强的实用价值,同时也为后期的辊锻模具制造和有限元模拟做好了强大的铺垫.%Combined with the method of UG expression and the tools of the UG secondary development including UG/Open MenuScript, UG/Open UIStyler, UG/Open API and Visual C+ +6.0,the roll-forging system of precision and billet on automotive front axle was developed based on the front axle forging process theory. In this system, the front axle forging and die was easily modified, and any front axle forging designer could handle it with much convenience.This method brings practical values for improving efficiency of front axle forging die design and shortening the die development period, meanwhile, making a strong fundament for the following roll-forging die production and finite element method.

  18. 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 fe...

  19. Vienna-Rotterdam: Forging the Future Urban strategies compared

    NARCIS (Netherlands)

    Rosemann, J.; Wigmans, G.

    1996-01-01

    De rol van de publieke planning en de mogelijkheid (en ook de wenselijkheid) om de stedelijke ontwikkeling in het postindustriële tijdperk te sturen zijn de centrale thema's van de conferentie "Vienna - Rotterdam: Forging the Future". De conferentie wordt georganiseerd door de bouwkundefaculteiten v

  20. 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...

  1. Gao Qingmin:Forging a Legend Back to Life

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    SWORD-MAKER Gao Qingmin first dreamt of making swords when standing by his father at the furnace. As a teenager, he was apprenticed to his blacksmith father Gao Xikun, and schooled in stories of master ironsmiths Ou Yezi and Gan Jiang,both famous for forging highquality Tangxi swords.

  2. Parallelisation of seismic algorithms using PVM and FORGE

    NARCIS (Netherlands)

    Wedemeijer, H.; Cox, H.L.H.; Verschuur, D.J.; Ritsema, I.L.

    1996-01-01

    The processing of seismic data, for the imaging of the earth's subsurface, is pushing current computational possibilities to the limit. In this paper results are presented obtained by optimisation and parallelisation of two innovative seismic algorithms with the use of PVM and FORGE. It shows that w

  3. strength and ductility of forged 1200 aluminum alloy reinforced with ...

    African Journals Online (AJOL)

    eobe

    Results show that forged composites with 106μm had a tensile strength .... W. Ag. Sn. Co. % Composition 0.243 0.004 0.005 0.08 0.01. Element. Ni. Cr. Mo. % Composition .... parameters on the porosity content in Al(Mg)-Al2O3 cast particulate ...

  4. 高锰无磁钢护环锻造特点及锻造工艺%Forging characteristics and process of high manganese non-magnetic steel retaining ring

    Institute of Scientific and Technical Information of China (English)

    曾艳玲

    2013-01-01

    The forging process requirement of high manganese steel retaining ring is relatively high.According to the forging characteristics of high manganese steel retaining ring,the forging process development and improving measures were put forward.After trial production,the satisfied effect was obtained.By carrying out the improved forging process in the factory,the influence of forging characteristics for high manganese steel on forging process was reduced,the internal and appearance qualities of retaining ring and the tooling life were improved,and the heating number and energy consumption were reduced.%高锰无磁钢护环在加工过程中的锻造工艺要求比较高,本文在针对高锰无磁钢护环锻造特点的基础上,提出了对锻造过程的工艺开发及改进措施.经试制后达到了令人满意的效果,将经过改良后的锻造工艺在工厂里进行实施,降低了高锰无磁钢锻造特点对锻造工艺的影响,提高了护环的内部质量和外观质量,同时也提高了工装的寿命,减少了生产火次和能源的消耗.

  5. Genome-wide mapping of hot spots of DNA double-strand breaks in human cells as a tool for epigenetic studies and cancer genomics

    Directory of Open Access Journals (Sweden)

    N.A. Tchurikov

    2015-09-01

    Full Text Available Hot spots of DNA double-strand breaks (DSBs are associated with coordinated expression of genes in chromosomal domains (Tchurikov et al., 2011 [1]; 2013. These 50–150-kb DNA domains (denoted “forum domains” can be visualized by separation of undigested chromosomal DNA in pulsed-field agarose gels (Tchurikov et al., 1988; 1992 and used for genome-wide mapping of the DSBs that produce them. Recently, we described nine hot spots of DSBs in human rDNA genes and observed that, in rDNA units, the hot spots coincide with CTCF binding sites and H3K4me3 marks (Tchurikov et al., 2014, suggesting a role for DSBs in active transcription. Here we have used Illumina sequencing to map DSBs in chromosomes of human HEK293T cells, and describe in detail the experimental design and bioinformatics analysis of the data deposited in the Gene Expression Omnibus with accession number GSE53811 and associated with the study published in DNA Research (Kravatsky et al., 2015. Our data indicate that H3K4me3 marks often coincide with hot spots of DSBs in HEK293T cells and that the mapping of these hot spots is important for cancer genomic studies.

  6. Solution Examples of Selected Issues Related to Die Forging / Przykłady Rozwiązań Wybranych Zagadnień Związanych Z Kuciem Matrycowym

    Directory of Open Access Journals (Sweden)

    Gronostajski Z.

    2015-12-01

    Full Text Available The paper presents selected examples of solutions and specific user applications associated with the industrial forging processes. Various process specific issues encountered during many years of bilateral collaboration with the forging industry are addressed and analysis methods are presented. As demonstrated in numerous articles and publications, the parameters influencing the die forging process are subject to complicated and mutually related dependencies, which can affect and complicate the methods of analysis. For this reason, researchers, more and more frequently, involve the use of additional support tools such as CAD / CAM / CAE, numerical modelling based on FEM, tool surface scanning methods, physical modelling, advanced microstructural research and dedicated control-measurement systems to validate engaged solutions. The research conducted by the authors included mainly: an analysis of the preform preparation, the impact of the geometry on the forging quality and the heating methods of the material and the tools, analysis of the tribological conditions, as well as an optimization of selected processes in respect of the force parameters, strain and temperature distributions and finally, a weight minimization of the input material. The issues discussed by the authors in the article intend, on the basis of the experience of its creators, to review the issues of the current forging technology and to indicate its possible solutions and development directions.

  7. Adjustable broaching tool for tolerance compensation in precision manufacturing

    DEFF Research Database (Denmark)

    Nielsen, Emil Krabbe; Eriksen, Rasmus Solmer; Paldan, Nikolas Aulin

    2015-01-01

    , and their tolerances are not compliant. This approach presents a precision broaching tool for adjusting the inner diameter of an external broach. The tool compensates for the manufacturing tolerance chain of tool and workpieces by up to 37 m. The approach is based on conventional shrink fitting of cold forging tools...

  8. The Numerical Analysis of the Phenomena of Superficial Hardening of the Hot-Work Tool Steel Elements / Analiza Numeryczna Zjawisk Przypowierzchniowego Hartowania Elementów Ze Stali Narzędziowej Do Pracy Na Gorąco

    Directory of Open Access Journals (Sweden)

    Bokota A.

    2015-12-01

    Full Text Available In the paper the complex model of hardening of the hot-work tool steel is presented. Model of estimation of phase fractions and their kinetics is based on the continuous heating diagram (CHT and cooling diagram (CCT. Phase fractions which occur during the continuous heating and cooling (austenite, pearlite or bainite are described by Johnson-Mehl (JM formula. To determine of the formed martensite the modified Koistinen-Marburger (KM equation is used. Model takes into account the thermal, structural, plastic strains and transformation plasticity. To calculate the plastic strains the Huber-Mises plasticity condition with isotopic hardening is used. Whereas to determine transformations induced plasticity the Leblond model is applied. The numerical analysis of phase compositions and residual stresses in the hot-work steel (W360 element is considered.

  9. 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.

  10. Prevention of thinning at disc center during rotary forging

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents the simulation and analysis of the rotary forging of a disc using a finite element method, which re veals the thinning at the disc center is caused by higher radial and tangential tensile stresses resulting from the local loading of a rotary die and acting at the center of a workpiece, and proposes a new design of rotary die with a hole opened in its center to prevent the continuous occurrence of shortening in the axial direction and elongation in the tan gential and radial directions, and concludes from simulation results that the rotary die with a hole opened in its center is effective for prevention of thinning or cracking at the center of a disc during rotary forging.

  11. 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.

  12. Forging process modeling of cone-shaped posts

    Institute of Scientific and Technical Information of China (English)

    Xuefeng Liu; Lingyun Wang; Li Zhang

    2004-01-01

    Using the rigid visco-plastic Finite Element Method (FEM), the process of forging for long cone-shaped posts made of aluminum alloys was modeled and the corresponding distributions of the field variables were obtained based on considering aberrance of grids, dynamic boundary conditions, non-stable process, coupled thermo-mechanical behavior and other special problems.The difficulties in equipment selection and die analysis caused by the long cone shape of post, as well as by pressure calculation were solved.

  13. A Short Study of Large Rotary Forged Cylinders

    Science.gov (United States)

    1979-06-01

    Bottom) 7 Microstructure at mid-wall of reheat treated rotary 25 forged cylinders - Martensite- Bainite 8 Martensitic microstructure of (a) normalized...also was unsatisfactory (Table 2). The microstructure at the mid-wall of both the top and bottom showed evidence of ferrite and bainite (Figs. 1 and...austenitized, and of bainite , showing that the material transformed to austenite had been in- adequately quenched, since martensite is the desired product

  14. FEM simulation for cold press forging forming of the round-fin heat sink

    Science.gov (United States)

    Wang, Kesheng; Han, Yu; Zhang, Haiyan; Zhang, Lihan

    2013-05-01

    In this paper, the finite element method is used to investigate the forming process of cold press forging for the round-fin heat sink in the automotive lighting. A series of simulations on the round-fin heat sink forming using the program DEFORM were carried out. The blank thickness and friction coefficient on the formation of round-fin were studied, and the tooling structure with counterpressure on the heat sink formation was also investigated. The results show that the blank thickness is very good for the round-fin formation, and the thicker the blank is, the better the round-fin can be formed; and also When both the punch-blank interface and the die-blank interface have the same value of friction factor, the larger value of friction factor is in favor of round-fin forming, the further investigation reveals that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin. Meanwhile, The tooling structure with counterpressure is helpful to the formation of round-fin heat sink, which not only ensures the height of each round-fin on the heat sink is uniform but also retards the initiation of flow-through on the reverse side of round-fin. In addition, the experiments of press forging process were conducted to validate the finite element analysis, and the simulation results are in good agreement with the experimental data.

  15. Numerical simulation on forging process of TC4 alloy mounting parts

    Institute of Scientific and Technical Information of China (English)

    L(U) Cheng; ZHANG Li-wen

    2006-01-01

    In order to eliminate forging defects appearing in production, based on the rigid-viscoplastic FEM principle, the DEFORM3D software package was employed to simulate the forming process of TC4 alloy mounting part and to optimize the process parameters. In this simulation, the temperature dependency of the thermal and mechanical properties of material was considered. Based on the simulation, the metal flow and thermomechanical field variables such as stress and damage are obtained.The simulation results show that the forging defects are caused by improper die dimension and the optimized die dimension was proposed. To verify the validity of simulation results, forging experiments were also carried out in a forging plant. The forging experiments show that the optimized die dimension can ensure the quality of forging part, and it can provide reference to improve and optimize die design process.

  16. 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.

  17. Research on Integrated Casting and Forging Process of Aluminum Automobile Wheel

    Directory of Open Access Journals (Sweden)

    Qi Zhang

    2014-07-01

    Full Text Available Integrated casting and forging process (ICFP is a new manufacturing method combining the advantages of both casting and forging. Aluminum structure parts, such as aluminum alloy automobile wheel, with complex shape and excellent mechanical properties can be produced by this process. The effects of different process parameters on the ICFP of the automobile wheel were simulated by Forge software. Microstructure of forging region and the nonforging region were studied by experiment. The results show that die temperature, static pressure of the injection piston, forging speed, and material flow have significant influences on the process. Compared with nonforging region, the microstructure of forging region becomes finer, more uniform, and denser. Meanwhile, the casting defects can be removed and mechanical properties improved.

  18. Measurement and Analysis on Hardness and Residual Stress of Heavy Forging after Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The hardness and residual stress in the forging for cold roller during low temperature tempering, and the relationship of residual stress and cooling temperature of high temperature tempering for heavy forgings were studied. The stress relaxation constant at low temperature tempering and the elasto-plastisity inversion temperature at high temperature tempering were found. The results are of great importance to determine rational tempering cooling process of heavy forgings.

  19. DK20连杆高能螺旋压力机精密模锻工艺%Precision die forging technology using high power screw press for DK20 connecting rod

    Institute of Scientific and Technical Information of China (English)

    詹辉

    2013-01-01

    Focusing on the hammer die forging technology deficiency of DK20 connecting rod,the technology of precision die forging on the high power screw press production line was put forward,the design issues of each tooling process were described,and the effective solutions for the problems during the production were resolved.Compared with the hammer die forging,a medium frequency induction heating,the triple-pass roll forging blanks were adopted,and the process of trimming first by press and then punching compound die and calibration was applied,which avoided three processes of free forging billets,carbon tempering and machining holes,achieved residual heat quenching and tempering for forging.The forgings manufacturing costs were reduced by more than 20%,the production cycle was shortened by 50%.%针对DK20连杆锤上模锻工艺的不足,提出了在高能螺旋压力机生产线上进行精密模锻的工艺方案,描述了各工步工装设计要点,对生产中存在的问题制定了有效的解决方案.与锤上模锻工艺相比,采用中频感应加热、三道次辊锻制坯,应用油压机先切边、再进行复合模冲孔和校正的工艺,减少了自由锻出坯、增碳调质、机加工大孔3道工序,实现了锻件余热调质,锻件制造成本降低20%以上,生产周期缩短50%.

  20. Cross dies forging: A new method to reduce forging force & price up to 80% thanks to FEM method

    Directory of Open Access Journals (Sweden)

    Mansouri Hamid

    2016-01-01

    Full Text Available Purpose of this article was to introduce a new method of forging which is called “Cross Die Forging”. In this method, the required force (load is reduced to the greatest possible degree through elimination of flash channel; however, this would also decrease the positive effect of flash channel, namely filling the gaps and pores within the mold. Cross die forging procedure provides a way for providing a better preform design which ensures that the mold is filled without allowing the material to enter the flash channel. This method has been invented based on the need to decrease the production costs and to use lower tonnage pressing devices for production of heavy parts. This method is an economical method only for parts that: A Has at least one plane of symmetry and the two ends that are perpendicular to the symmetry plane are flat; B Has a weight that makes it impossible to be manufactured by rolling or roll forging processes. Examples of such parts are valve’s body, T-junctions, etc.

  1. Path planning and kinematics simulation of surfacing cladding for hot forging die

    National Research Council Canada - National Science Library

    Wang, Huajun; Fu, Wanxia; Ou, Hengan; Tang, Xuan

    2015-01-01

    .... Based on technological requirements of surface cladding for die cavity, the coupled movement equation of weld torch was established, and the trajectory of welding positioner and Cartesian robot kinematics was solved...

  2. A phenomenological constitutive equation for Rene 95 PM alloy and its application to isothermal forging process of turbine disk

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The flow behavior of Rene 95 PM alloy was studied from 1050 to 1150℃with strain rate of 1€?10, 1€?10, 1€?10 and 1. At a given temperature and strain rate, flow curves exhibit a peak followed by flow softening up to a steady state. Moreover, at constant strain, flow stress increases with increasing strain rate and decreasing temperature. An equation relating hyperbolic sine of flow stress to hot working parameters, such as strain, strain rate and temperature, was established by using multiple nonlinear regression method. A very good agreement was found between predicted and experimental flow stress in all the strain range investigated. Application of the constitutive equation in predicting forming loads and flow behavior and temperature distribution in both upper and lower dies in an isothermal forging process of turbine disk of large dimension (about 630mm) by means of a finite element code was systematically analyzed.

  3. Hot Tickets

    Science.gov (United States)

    Fox, Bette-Lee; Hoffert, Barbara; Kuzyk, Raya; McCormack, Heather; Williams, Wilda

    2008-01-01

    This article describes the highlights of this year's BookExpo America (BEA) held at the Los Angeles Convention Center. The attendees at BEA had not minded that the air was recycled, the lighting was fluorescent, and the food was bad. The first hot book sighting came courtesy of Anne Rice. Michelle Moran, author of newly published novel, "The…

  4. Influence and prediction of hot deformation parameters on microstructure of Ti-15-3 alloy

    Institute of Scientific and Technical Information of China (English)

    李萍; 薛克敏; 吕炎; 谭建荣

    2002-01-01

    The effect of hot processing parameters on the microstructure of Ti-15-3 alloy after solution treatment was studied by isothermal compression test and metallurgical analysis. Predicting models for the relations between equivalent grain size and recrystallized grain volume percent with strain,strain rate and temperature have been developed with an artificial neural network method. The coincidence of predicted results with measured ones shows that the neural network can predict the influence of hot deformation parameters on the microstructure of Ti-15-3 alloy after solution treatment successfully. These studies are significant for determining hot-forging processing parameters of Ti-15-3 alloy.

  5. Hot-Deformation Behavior and Hot-Processing Maps of AISI 410 Martensitic Stainless Steel

    Science.gov (United States)

    Qi, Rong-Sheng; Jin, Miao; Guo, Bao-Feng; Liu, Xin-Gang; Chen, Lei

    2016-10-01

    The compressive deformation behaviors of 410 martensitic stainless steel were investigated on a Gleeble-1500 thermomechanical simulator, and the experimental stress-strain data were obtained. The measured flow stress was corrected for friction and temperature. A constitutive equation that accounts for the influence of strain was established, and the hot-processing maps at different strain were plotted. The microstructure evolution of the hot-deformation process was studied on the basis of microstructural observations at high temperatures. Phase-transformation experiments on 410 steel were conducted at high temperatures to elucidate the effects of temperature on the delta-ferrite content. The initial forging temperature and optimum process parameters were obtained on the basis of the processing map and the changes in the delta-ferrite content at high temperatures.

  6. Manufacturing involving forging of multiple objects in contact

    DEFF Research Database (Denmark)

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

    Finite element modeling of multi-object manufacturing processes is presented with supporting experiments. The underlying finite element implementation is based on the flow formulation and further coupled with thermal and electrical models to accomplish electro-thermo-mechanical simulation. All...... 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...

  7. 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.

  8. 连杆锻模型槽设计及CAM%Design and CAM of Connecting Rod Forging Die

    Institute of Scientific and Technical Information of China (English)

    杨兆伟

    2011-01-01

    通过SolidWorks软件进行了连杆锻坯的建模,利用数值模拟结果指导完成了连杆锻模模具型槽的设计,确定了螺旋压力机的吨位.利用CAXAME软件的零件加工模块进行了工件的粗、精加工的设定,并且完成了刀具轨迹的加工模拟.利用软件的后置处理功能得到了NC代码,并使用高速加工技术完成了模具的高速切削加工.%The 3D modeling for connecting forging billet was set up by SolidWorks software.The design of cavity and flash groove of the forging die were completed based on the numerical simulation.The tonnage of spindle press was confirmed.The parameters for tools and cutting were set up by CAXAME software.The machining path for tooling was simulated.The NC code generated by software post-processer can be used to complete the high speed machining of mould.

  9. 大锻件 KD 压实锻造工艺模拟研究%Simulation Research of Compaction Forging Process for Large Forgings with KD Method

    Institute of Scientific and Technical Information of China (English)

    徐明昊; 王敬禹; 刘建红

    2013-01-01

      利用数值模拟方法对锻造过程中的锻造温度场、V型砧砧宽和布砧方式等工艺参数对锻件心部质量的影响进行了研究。结果表明,温度梯度、宽大V型砧和交替布砧的方式能够有效地提高锻件心部的压实效果。%The influence of the technological parameters during forging , such as forging temperature field, V shaped anvil width and anvil distribution mode on the quality of forging core is researched by numerical simulation .The result shows that the temperature gradient , V shaped wide anvil and alternating anvil distribution can effectively im-prove the compaction effect of forging core .

  10. 75 FR 67110 - Forged Stainless Steel Flanges From India and Taiwan

    Science.gov (United States)

    2010-11-01

    ... COMMISSION Forged Stainless Steel Flanges From India and Taiwan AGENCY: United States International Trade... stainless steel flanges from India and Taiwan. SUMMARY: The Commission hereby gives notice that it has... determine whether revocation of the antidumping duty orders on forged stainless steel flanges from India...

  11. [Research on the inner wall condition monitoring method of ring forgings based on infrared spectra].

    Science.gov (United States)

    Fu, Xian-bin; Liu, Bin; Wei, Bin; Zhang, Yu-cun; Liu, Zhao-lun

    2015-01-01

    In order to grasp the inner wall condition of ring forgings, an inner wall condition monitoring method based on infrared spectra for ring forgings is proposed in the present paper. Firstly, using infrared spectroscopy the forgings temperature measurement system was built based on the three-level FP-cavity LCTF. The two single radiation spectra from the forgings' surface were got using the three-level FP-cavity LCTF. And the temperature measuring of the surface forgings was achieved according to the infrared double-color temperature measuring principle. The measuring accuracy can be greatly improved by this temperature measurement method. Secondly, on the basis of the Laplace heat conduction differential equation the inner wall condition monitoring model was established by the method of separating variables. The inner wall condition monitoring of ring forgings was realized via combining the temperature data and the forgings own parameter information. Finally, this method is feasible according to the simulation experiment. The inner wall condition monitoring method can provide the theoretical basis for the normal operating of the ring forgings.

  12. MM 99.58 Physical modelling of Hammerhead forging, Vertical and Lateral load history

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Eriksen, Morten; Wanheim, Tarras

    1999-01-01

    The present report presents a laboratory setup with hammerhead forging, where the vertical and lateral force history is obtained under different process conditions......The present report presents a laboratory setup with hammerhead forging, where the vertical and lateral force history is obtained under different process conditions...

  13. Winter Weather at Valley Forge 1777-1778: A Lesson in Climatic Reconstruction.

    Science.gov (United States)

    Ansley, Mary Jane; Pritchard, Sandra F.

    1987-01-01

    Notes that the story of George Washington's encampment at Valley Forge is seldom told without reference to the bitter cold winter Washington and his troops endured. Shows how to use historical reports of weather information to allow students to judge for themselves whether the winter at Valley Forge then was harsher than winters in the same area…

  14. RESEARCH ON THE WARM FORGING OF ALUMINUM ALLOYS:DEVELOPMENT OF A FORMULA TO DESCRIBE THE SOFTENING BEHAVIOR OF A2011 IN FORGING PROCESS

    Institute of Scientific and Technical Information of China (English)

    X.H. Zhang, K. Osakada; X. Y. Ruan

    2003-01-01

    To understand the forming behaviour of aluminum alloys, the upsetting test of alu-minum alloys at evaluated temperature is conducted. Because in warm forging theflow stress decreases with increasing straining, which is so-called work softening, noappropriate material formulation is available. For the evaluation of flow stress ofaluminum alloys in warm forging processes, in this paper, a formula is derived byanalyzing the stress data measured at various temperatures. It is demonstrated thatthe formula fits the flow stress obtained from experiment.

  15. RESEARCH ON INFLUENCE OF TEMPERATURE ON A PRECISION FORGING PROCESS OF BLADE WITH A TENON

    Institute of Scientific and Technical Information of China (English)

    Y.L. Liu; H. Yang; T. Gao; M. Zhan; W. Cai

    2005-01-01

    The blade precision forging process is a forming process with high temperature and large plastic deformation. Interaction of deformation and heat conduction leads to large uneven distribution of temperature. The unevenness of temperature distribution has a great effect on mechanical properties and the microstructure of materials. So it is necessary to consider the influence of temperature on the precision forging process of blades. Taking a blade with a tenon into consideration, a 3D mechanical model in precision forging is built up. The distribution laws of temperature field and the influence of the temperature on the equivalent stress in the process are obtained by using 3-D coupled thermo-mechanical FEM code developed by the authors. The results obtained illustrate that the influence of the temperature field on the blade forging process is considerable. The achievements of predicting microstructure and mechanical properties for forged blades is significant.

  16. HYDROGEN-ASSISTED FRACTURE IN FORGED TYPE 304L AUSTENITIC STAINLESS STEEL

    Energy Technology Data Exchange (ETDEWEB)

    Switzner, Nathan; Neidt, Ted; Hollenbeck, John; Knutson, J.; Everhart, Wes; Hanlin, R. [University of Missouri-Kansas City; Bergen, R. [Precision Metal Products; Balch, D. K. [Sandia Natl Laboratory

    2012-09-06

    Austenitic stainless steels generally have good resistance to hydrogen-assisted fracture; however, structural designs for high-pressure gaseous hydrogen are constrained by the low strength of this class of material. Forging is used to increase the low strength of austenitic stainless steels, thus improving the efficiency of structural designs. Hydrogen-assisted racture, however, depends on microstructural details associated with manufacturing. In this study, hydrogen-assisted fracture of forged type 304L austenitic stainless steel is investigated. Microstructural variation in multi-step forged 304L was achieved by forging at different rates and temperatures, and by process annealing. High internal hydrogen content in forged type 304L austenitic stainless steel is achieved by thermal precharging in gaseous hydrogen and results in as much as 50% reduction of tensile ductility.

  17. 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.

  18. 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.

    2016-09-01

    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.

  19. Hot Money,Hot Problems

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    After emerging from the economic doldrums, developing economies are now confronted with a new danger-a flood of international hot money. But how has the speculative capital circumvented regulatory controls and what are the consequences concerning the stability of the developing world? Zhao Zhongwei, a senior researcher with the Institute of World Politics and Economics at the Chinese Academy of Social Sciences, discussed these issues in an article recently published in the China Securities Journal. Edited excerpts follow

  20. Influence of Chemical Composition on Rupture Properties at 1200 Degrees F. of Forged Chromium-Cobalt-Nickel-Iron Base Alloys in Solution-Treated and Aged Condition

    Science.gov (United States)

    Reynolds, E E; Freeman, J W; White, A E

    1951-01-01

    The influence of systematic variations of chemical composition on rupture properties at 1200 degrees F. was determined for 62 modifications of a basic alloy containing 20 percent chromium, 20 percent nickel, 20 percent cobalt, 3 percent molybdenum, 2 percent tungsten, 1 percent columbium, 0.15 percent carbon, 1.7 percent manganese, 0.5 percent silicon, 0.12 percent nitrogen and the balance iron. These modifications included individual variations of each of 10 elements present and simultaneous variations of molybdenum, tungsten, and columbium. Laboratory induction furnace heats were hot-forged to round bar stock, solution-treated at 2200 degrees F., and aged at 1400 degrees F. The melting and fabrication conditions were carefully controlled in order to minimize all variable effects on properties except chemical composition. Information is presented which indicates that melting and hot-working conditions play an important role in high-temperature properties of alloys of the type investigated.

  1. Are 'hot spots' hot spots?

    Science.gov (United States)

    Foulger, Gillian R.

    2012-07-01

    The term 'hot spot' emerged in the 1960s from speculations that Hawaii might have its origins in an unusually hot source region in the mantle. It subsequently became widely used to refer to volcanic regions considered to be anomalous in the then-new plate tectonic paradigm. It carried with it the implication that volcanism (a) is emplaced by a single, spatially restricted, mongenetic melt-delivery system, assumed to be a mantle plume, and (b) that the source is unusually hot. This model has tended to be assumed a priori to be correct. Nevertheless, there are many geological ways of testing it, and a great deal of work has recently been done to do so. Two fundamental problems challenge this work. First is the difficulty of deciding a 'normal' mantle temperature against which to compare estimates. This is usually taken to be the source temperature of mid-ocean ridge basalts (MORBs). However, Earth's surface conduction layer is ˜200 km thick, and such a norm is not appropriate if the lavas under investigation formed deeper than the 40-50 km source depth of MORB. Second, methods for estimating temperature suffer from ambiguity of interpretation with composition and partial melt, controversy regarding how they should be applied, lack of repeatability between studies using the same data, and insufficient precision to detect the 200-300 °C temperature variations postulated. Available methods include multiple seismological and petrological approaches, modelling bathymetry and topography, and measuring heat flow. Investigations have been carried out in many areas postulated to represent either (hot) plume heads or (hotter) tails. These include sections of the mid-ocean spreading ridge postulated to include ridge-centred plumes, the North Atlantic Igneous Province, Iceland, Hawaii, oceanic plateaus, and high-standing continental areas such as the Hoggar swell. Most volcanic regions that may reasonably be considered anomalous in the simple plate-tectonic paradigm have been

  2. 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.

  3. 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. 

  4. Hot Deformation Behavior and Microstructural Evolution of a Medium Carbon Vanadium Microalloyed Steel

    Science.gov (United States)

    Cutrim, Rialberth M.; Rodrigues, Samuel F.; Reis, Gedeon S.; Silva, Eden S.; Aranas, Clodualdo; Balancin, Oscar

    2016-11-01

    Hot forging of steel requires application of large strains, under which conditions, dynamic recrystallization (DRX) is expected to take place. In this study, torsion tests were carried out on a medium carbon vanadium microalloyed steel (38MnSiVS5) to simulate hot forging. Deformations were applied isothermally in the temperature range 900-1200 °C at strain rates of 0.1-10 s-1 in order to observe for the occurrence of DRX and to investigate for the microstructural evolution during straining. The shape of the flow curves indicated that the recrystallization takes place during deformation. This was supported by optical microscopy performed on the quenched samples which displayed considerable amounts of recrystallized grains. It was shown that the grain size depends on straining conditions such as strain rate and temperature. Finally, it was revealed that these process parameters can considerably affect the evolution of microstructure of industrial grade steels by means of DRX.

  5. Using of material-technological modelling for designing production of closed die forgings

    Science.gov (United States)

    Ibrahim, K.; Vorel, I.; Jeníček, Š.; Káňa, J.; Aišman, D.; Kotěšovec, V.

    2017-02-01

    Production of forgings is a complex and demanding process which consists of a number of forging operations and, in many cases, includes post-forge heat treatment. An optimized manufacturing line is a prerequisite for obtaining prime-quality products which in turn are essential to profitable operation of a forging company. Problems may, however, arise from modifications to the manufacturing route due to changing customer needs. As a result, the production may have to be suspended temporarily to enable changeover and optimization. Using material-technological modelling, the required modifications can be tested and optimized under laboratory conditions outside the plant without disrupting the production. Thanks to material-technological modelling, the process parameters can be varied rapidly in response to changes in market requirements. Outcomes of the modelling runs include optimum parameters for the forging part’s manufacturing route, values of mechanical properties, and results of microstructure analysis. This article describes the use of material-technological modelling for exploring the impact of the amount of deformation and the rate of cooling of a particular forged part from the finish-forging temperature on its microstructure and related mechanical properties.

  6. 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.

  7. Identification of Project Risks & Risk Breakdown Structure In Manufacture of Heavy Forgings

    Directory of Open Access Journals (Sweden)

    D.K.Singh

    2014-10-01

    Full Text Available Forging companies, especially in the business of manufacture of heavy forged parts are embedded in the supply chain of critical components of capital goods across various industries. These forged parts form a significant portion of the total raw material requirement of the capital goods equipment and is generally on the critical path of project schedule.Failure to meet delivery schedule poses huge threat to the success of the customer’s project. Delivery of these forged items is delayed in an event of failure to meet customer’s quality requirements.Various other uncertainties during the project lifecyclecan also cause delayed delivery. Accordingly, risk management methodologies when employed by the forging supplier to the manufacturing project can result in successful achievement of delivery timelines. The present study is intended to identify the risks (threats to quality and delivery in manufacture of heavy forged components and create a Risk breakdown structure (RBS as a reference for further risk planning by the forging supplier.

  8. Effects of Deep Cryogenic Treatment on the Wear Resistance and Mechanical Properties of AISI H13 Hot-Work Tool Steel

    Science.gov (United States)

    Çiçek, Adem; Kara, Fuat; Kıvak, Turgay; Ekici, Ergün; Uygur, İlyas

    2015-11-01

    In this study, a number of wear and tensile tests were performed to elucidate the effects of deep cryogenic treatment on the wear behavior and mechanical properties (hardness and tensile strength) of AISI H13 tool steel. In accordance with this purpose, three different heat treatments (conventional heat treatment (CHT), deep cryogenic treatment (DCT), and deep cryogenic treatment and tempering (DCTT)) were applied to tool steel samples. DCT and DCTT samples were held in nitrogen gas at -145 °C for 24 h. Wear tests were conducted on a dry pin-on-disk device using two loads of 60 and 80 N, two sliding velocities of 0.8 and 1 m/s, and a wear distance of 1000 m. All test results showed that DCT improved the adhesive wear resistance and mechanical properties of AISI H13 steel. The formation of small-sized and uniformly distributed carbide particles and the transformation of retained austenite to martensite played an important role in the improvements in the wear resistance and mechanical properties. After cleavage fracture, the surfaces of all samples were characterized by the cracking of primary carbides, while the DCT and DCTT samples displayed microvoid formation by decohesion of the fine carbides precipitated during the cryo-tempering process.

  9. Effect of Technical Quality of Thermomechanical Die Forging of AA2099 Alloy

    Directory of Open Access Journals (Sweden)

    Łukaszek-Sołek A.

    2014-10-01

    Full Text Available The paper presents the results of investigations of a multicomponent third-generation aluminium alloy, classified as AA2099. The actual forging conditions were determined basing on the assessment of the quality of side surface of specimens subjected to compression in Gleeble 3800 simulator and on flow curves of the alloy, as well as numerical modelling of forging process performed with application of QForm 3D v.7 software. Compression tests were realized at temperatures 400-500 °C, with a strain rate of 0.001-100 s-1, up to a specified constant true strain value of 0.9. Microstructure examination in as-delivered state was performed with application of Leica DM 4000M optical microscope. The obtained results of isothermal deformation of specimens were correlated with the analysis of a characteristic layered pancake-type microstructure. The simulation of die forging of a complex-shape forging (high-current contact tip used in power engineering at the temperature 500 °C, was performed. The shape of a forging makes it possible to fully analyse the influence of thermomechanical process conditions on technical quality of a product. The simulation of forging process showed full correctness of material flow, with no signs of instability. At the same time, the analysis of investigations allowed to prepare and realize the industrial forging trials for a forging of a very complex shape, in a single step, at the temperature 500 °C, with application of thermomechanical treatment. The forging attained high quality of shape and surface. Directional specimens were taken, in order to be subjected to microstructure examination and hardness testing. The data obtained from industrial tests, combined with the results of testing using Gleeble simulator as well as from numerical modelling, make up the guidelines for mechanical processing of AA2099 alloy at the temperatures 470-500 °C.

  10. 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...... of a centreline hole in a single compression operation. Friction is also taken into account. The numerical analysis indicates that a lower die angle of approximately 140o results in the largest centreline hole closure for a wide range of material hardening. The value of optimum die angle is not influenced...... by friction, which was found only to change the degree of centreline porosity closure in case of small lower die angle....

  11. Processing map for hot working of as extruded AZ31B magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    HUANG Guang-sheng; HUANG Guang-jie; WANG Ling-yun; PAN Fu-sheng

    2005-01-01

    The deformation behavior of AZ31B magnesium alloy as extruded under hot compression conditions was characterized in the temperature range of 200 - 400 ℃ and strain rate range of 0. 001 - 1 s-1. The processing maps were obtained at different strains. The results show that the map exhibits flow instabilities as two domains. The domain at beyond 300 ℃ and strain rate of 1 s-1 appears with a peak efficiency of power dissipation about 56% occurring. This domain is expected to happen in a hot process, such as hot rolling, hot extrusion and hot forging. There is high efficiency of power dissipation at temperature beyond 350 ℃ and strain rate 0. 001 s-1. Such domains suggest the occurrence of superplastic deformation.

  12. 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.

  13. Microstructural evolution and mechanical properties of hypereutectic Al–Si alloy processed by liquid die forging

    Indian Academy of Sciences (India)

    F F Wu; S T Li; G A Zhang; F Jiang

    2014-08-01

    The microstructural evolution and mechanical properties of a hypereutectic Al–Si alloy processed by liquid die forging were investigated. It is found that the grain size of the primary Si was significantly reduced by liquid die forging with increased pressure. The volume fraction of eutectic silicon was decreased with increased pressure. By liquid die forging with pressure up to 180 MPa, the average size of the primary Si was reduced to about 18 m, which results in the remarkable increase in the fracture strength and hardness of the hypereutectic Al–Si alloy.

  14. 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.

  15. Research on forging method of marine long-shaft heaving forging%船用长轴类大锻件锻造工艺方法研究

    Institute of Scientific and Technical Information of China (English)

    夏琴香; 向可; 赵学智; 李一振

    2013-01-01

    船用长轴类大锻件是船舶动力装置的重要组成部分,其质量好坏直接影响船舶的推进特性和正常航行.本文以某船用中间轴为研究对象,对普通平砧锻造法、FM锻造法和上下砧不等宽锻造方法下的压方过程进行了数值模拟,应用数值模拟软件Deform-3D建立了相应的有限元模型,对坯料温度场、应力分布、锻造力和锻造效率进行了分析.结果表明:采用平砧锻造时,锻件的锻造效率最高,所需锻造力小,且表面温度下降最慢;采用FM法锻造时能获得较理想的压应力分布状态.%As the most important components of marine power installation, the quality of the long-axis heavy forgings has a direct influence on the hydrodynamic characteristics and normal voyage of marine. The squaring process of the marine intermediate shaft forged by flat anvil, FM method and the unequal flat anvil was simulated. The finite element model was established based on numerical simulation software Deform-3D, and the temperature field, stress distribution, forging force and forging efficiency were analyzed. The results show that comparing with the FM method and unequal flat anvil forging, when forging by flat anvil, the forming efficiency is the highest, the forging force is the smallest and the deceasing speed of the surface temperature of forging billet is the slowest; when forging by FM method, the ideal compressive stress distribution state can be obtained along the billet cross section.

  16. Theoretical and experimental research of hammer forging process of RIM from AZ31 magnesium alloy

    Directory of Open Access Journals (Sweden)

    A. Gontarz

    2014-10-01

    Full Text Available The results of theoretical analysis and experimental tests of hammer forging process of rim part from AZ31 magnesium alloy are presented in this paper. On the basis of numerical simulation results, the analysis of limiting phenomena was made. These phenomena include: possibility of overlapping presence, not filling of die impression, overheating of material and cracks. The results of theoretical analysis provided the support for planning of experimental tests in industrial conditions. Forging tests were conducted in one of Polish forming plants, applying steam-air hammer of blow energy 63 kJ. On the basis of experimental verification, it was stated that it is possible to obtain rim forging from AZ31 alloy of assumed quality in the hammer forging process.

  17. Sensitivity Analysis Based Multiple Objective Preform Die Shape Optimal Design in Metal Forging

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The multiple objective preform design optimization was put forward. The final forging's shape and deformation uniformity were considered in the multiple objective. The objective is to optimize the shape and the deformation uniformity of the final forging at the same time so that a more high integrate quality of the final forging can be obtained. The total objective was assembled by the shape and uniformity objective using the weight adding method. The preform die shape is presented by cubic B-spline curves. The control points of B-spline curves are used as the design variables. The forms of the total objective function, shape and uniformity sub-objective function are given. The sensitivities of the total objective function and the sub-objective functions with respect to the design variables are developed. Using this method, the preform die shape of an H-shaped forging process is optimally designed. The optimization results are very satisfactory.

  18. Spatial Vegetation Data for Valley Forge National Historical Park Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — The vegetation and landcover of Valley Forge National Historical Park (VAFO) were mapped to the association level of the National Vegetation Classification System...

  19. Color Orthorectified Photomosaic for Valley Forge National Historical Park Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — Orthorectified color infrared Imagine image of Valley Forge NHP. Produced from 49 color infrared photos taken September 1999. Orthorectification accomplished with...

  20. Simulation and Analysis of Microstructure Evolution of IN718 in Rotary Forgings by FEM

    Institute of Scientific and Technical Information of China (English)

    YU Zhong-qi; MA Qiu; LIN Zhong-qin

    2008-01-01

    A numerical analysis was performed to study the influence of process parameters on the microstructure evolution of IN718 alloy in rotary forging using the finite element method (FEM).For this purpose,a constitutive equation considering the effects of strain hardening and dynamic softening of IN718 alloy was built.The constitutive equation and microstructure models were implemented into the finite element code to investigate the microstructure evolution during rotary forging subject to large deformations.The simulations were carried out in the ratio of initial height to diameter range 0.2-0.8,the angle of the rocker 3°-7° and the relative feed per revolution range 0.01-0.1 r-1.The research results revealed the deformation mechanism and the correlation of process parameters with the grain size evolution of IN718 alloy during rotary forging.These provide evidence for the selection of rotary forging parameters.

  1. Field Plot Points Modified for Valley Forge National Historical Park Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — This shapefile includes the locations of vegetation classification sampling plots used to develop an association-level vegetation classification of Valley Forge...

  2. Numerical analysis of rheological and tribological behavior influence on 16MnCr5 forging fibering

    Science.gov (United States)

    Gavrus, A.; Pintilie, D.; Nedelcu, R.

    2016-10-01

    The present research work is focus on the influence of the rheological constitutive equation and friction law formulation on 16MnCr5 forging fibering. Numerical analysis using FE Forge® and Abaqus code show the importance of the rheological softening terms on the metals fibers morphology and position coordinate. Calibration of friction law and sensitivity of softening parameters corresponding to a Hansel-Spittel rheological equation have been studied.

  3. Establishment of a Process for Creep Forging Aluminum Alloy Weapon Components

    Science.gov (United States)

    1978-04-01

    the important powder particle character- istics are mean particle size and size distribution, dendritic cell size and pattern, internal voids , and...Geometry Forging No. 26 (Fig. 53) showed excellent die filling except for a slight underfill at the tallest rib. Minor cracking also occurred over a small...Much cracking and underfill In rib detal1. 0.2 750 400 1 Some cracking Trimmed weight, 3.0 lb. 0.1 830 150 - Forged

  4. 搅拌摩擦焊中锻压效应的强化与作用%Effect and enhancement of forging action during friction stir welding

    Institute of Scientific and Technical Information of China (English)

    张贵锋; 苏伟; 张军; 张建勋

    2011-01-01

    To visualize the fact that the forging effect can be enhanced by tilting tool during friction stir welding,a novel experimental way,in which a backing plate with predrilled hole was used, was proposed and expected result was obtained. Using a tool without pin and a backing plate with a predrilled hole(Φ4 mm) the friction lap welding of 2 mm thick aluminum sheet was performed under the conditions of tilting tool(3°) and not tilting tool(0°).The length of plasticized aluminum extnlded into predrilled hole within backing plate was 5.3 mm and 2.6 mm at different tilting angle of 3° and 0° ,respectively.The result indicated that the forging effect can be enhanced by tilting tool,the primary loaded body of forging effect should be plasticized material at trading edge of pin (but beneath shoulder) , and the primary loading body of forging effect should be shoulder especially when using smooth pin without thread. Based on the above result,a mathematical relationship between axial forging pressure and tilt angle was proposed. It was derived from the mathematical relationship and comparative result of defect in the two kinds of welds with and without tilt angle that he forging effect has significant contribution to eliminating void defect behind pin due to the enhancement of plastic flow in multi-directions,especially in axial direction of tool.%为直观证明倾斜工具能强化搅拌搭接摩擦焊中的锻压效应之事实,提出了一种新的实验方案(采用预先开有小孔的垫板)并获得了预期效果.采用无针柱状搅拌头与预先开有φ4mm小孔的垫板,分别在有/无倾角的两种情况下进行了2 mm厚薄铝板的搭接搅拌摩擦焊.结果表明,在倾角为3°情况下被挤入垫板小孔内的塑化金属的长度(5.3 mm)远大于无倾角情况下的相应值(2.6 mm).可见,工具的倾斜可导入并强化焊缝中心区的锻压效应;锻压效应的受力体是针后高温软化金属;锻压效应的主要施力体应是肩,

  5. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    Science.gov (United States)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-10-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  6. Application of UG NX in forging die manufacturing%UGNX在锻模加工中的应用

    Institute of Scientific and Technical Information of China (English)

    孙劲松

    2012-01-01

    以汽车曲轴锻造的模具加工为例,选用UG NX CAM软件进行NC编程,利用UG的CAD和CAM集成,提高工作效率.对于锻模的难加工材料,可以选用TiAlN等涂层的刀具,尽量使用大直径的刀具以提高刚性.粗加工工艺可以采用摆线加工,以获得高加工效率和长刀具寿命.精加工先选用较大的刀具加工,再用小的刀具局部清根.%Taking crankshaft mould machining for example, working efficiency was improved by NC programming using UG NX CAM software and UG CAD/CAM integration. For the forging mould materials which are hard to machine, coating tools such as TiAlN were choosem, tools with as large as possible diameter were used to improve rigidity. Tro-choidal machining was used for rough machining process to get high efficiency and long life of tools. Finish machining process includes machining with larger tools first and flow cut with smaller tools.

  7. 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.

  8. Forged seal detection based on the seal overlay metric.

    Science.gov (United States)

    Lee, Joong; Kong, Seong G; Lee, Young-Soo; Moon, Ki-Woong; Jeon, Oc-Yeub; Han, Jong Hyun; Lee, Bong-Woo; Seo, Joong-Suk

    2012-01-10

    This paper describes a method for verifying the authenticity of a seal impression imprinted on a document based on the seal overlay metric, which refers to the ratio of an effective seal impression pattern and the noise in the neighborhood of the reference impression region. A reference seal pattern is obtained by taking the average of a number of high-quality impressions of a genuine seal. A target seal impression to be examined, often on paper with some background texts and lines, is segmented out from the background by an adaptive threshold applied to the histogram of color components. The segmented target seal impression is then spatially aligned with the reference by maximizing the count of matching pixels. Then the seal overlay metric is computed for the reference and the target. If the overlay metric of a target seal is below a predetermined limit for the similarity to the genuine, then the target is classified as a forged seal. To further reduce the misclassification rate, the seal overlay metric is adjusted by the filling rate, which reflects the quality of inked pattern of the target seal. Experiment results demonstrate that the proposed method can detect elaborate seal impressions created by advanced forgery techniques such as lithography and computer-aided manufacturing. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  9. Research on Hot Compressive Deformation of TiBw/TA15 Composite Cylindrical Billet with Network-Distributed Reinforcements

    Science.gov (United States)

    Zhang, Rui; Wang, DongJun; Yuan, ShiJian

    2017-08-01

    A TA15 matrix composite reinforced by 3.5 vol.% TiB whiskers with a network microstructure was fabricated by the reaction hot pressing method. After sintering, the composite developed a net-like microstructure. To improve the mechanical properties, a cylindrical billet of the as-sintered TiBw/TA15 composite was subjected to upsetting and swaging operations with intermediate heating at 1000°C. The original equiaxed network units were stretched slightly, and the matrix had a microstructure evolution from a basket structure to a bi-modal structure after hot forging. The results of tensile tests at room temperature showed that the ultimate tensile strength and elongation of the composite increased by 8.2% and 130%, respectively, while the yield strength appeared to remain constant. Furthermore, the mechanical properties of the as-forged composite also improved at an elevated temperature.

  10. Optimization and Mechanical Accuracy Reliability of a New Type of Forging Manipulator

    Institute of Scientific and Technical Information of China (English)

    CHEN Kang; MA Chunxiang; ZHENG Maoqi; GAO Feng

    2015-01-01

    Researches on forging manipulator have enormous influence on the development of the forging industry and national economy. Clamp device and lifting mechanism are the core parts of forging manipulator, and have been studied for longer time. However, the optimization and mechanical accuracy reliability of them are less analyzed. Based on General Function(GF) set and parallel mechanism theory, proper configuration of 10t forging manipulator is selected firstly. A new type of forging manipulator driven by cylinders is proposed. After solved mechanical analysis of manipulator’s core mechanisms, expressions of force of cylinders are carried out. In order to achieve smaller force afforded by cylinders and better mechanical characteristics, some particular sizes of core mechanisms are optimized intuitively through the combined use of the genetic algorithms(GA) and GUI interface in MATLAB. Comparing with the original mechanisms, optimized clamp saves at least 8 percent efforts and optimized lifting mechanism 20 percent under maximum working condition. Finally, considering the existed manufacture error of components, mechanical accuracy reliability of optimized clamp, lifting mechanism and whole manipulator are demonstrated respectively based on fuzzy reliability theory. Obtained results show that the accuracy reliability of optimized clamp is bigger than 0.991 and that of optimized lifting mechanism is 0.995. To the whole manipulator under maximum working condition, that value exceeds 0.986 4, which means that optimized manipulator has high motion accuracy and is reliable. A new intuitive method is created to optimize forging manipulator sizes efficiently and more practical theory is utilized to analyze mechanical accuracy reliability of forging manipulator precisely.

  11. Making randomised trials more efficient: report of the first meeting to discuss the Trial Forge platform.

    Science.gov (United States)

    Treweek, Shaun; Altman, Doug G; Bower, Peter; Campbell, Marion; Chalmers, Iain; Cotton, Seonaidh; Craig, Peter; Crosby, David; Davidson, Peter; Devane, Declan; Duley, Lelia; Dunn, Janet; Elbourne, Diana; Farrell, Barbara; Gamble, Carrol; Gillies, Katie; Hood, Kerry; Lang, Trudie; Littleford, Roberta; Loudon, Kirsty; McDonald, Alison; McPherson, Gladys; Nelson, Annmarie; Norrie, John; Ramsay, Craig; Sandercock, Peter; Shanahan, Daniel R; Summerskill, William; Sydes, Matt; Williamson, Paula; Clarke, Mike

    2015-06-05

    Randomised trials are at the heart of evidence-based healthcare, but the methods and infrastructure for conducting these sometimes complex studies are largely evidence free. Trial Forge ( www.trialforge.org ) is an initiative that aims to increase the evidence base for trial decision making and, in doing so, to improve trial efficiency.This paper summarises a one-day workshop held in Edinburgh on 10 July 2014 to discuss Trial Forge and how to advance this initiative. We first outline the problem of inefficiency in randomised trials and go on to describe Trial Forge. We present participants' views on the processes in the life of a randomised trial that should be covered by Trial Forge.General support existed at the workshop for the Trial Forge approach to increase the evidence base for making randomised trial decisions and for improving trial efficiency. Agreed upon key processes included choosing the right research question; logistical planning for delivery, training of staff, recruitment, and retention; data management and dissemination; and close down. The process of linking to existing initiatives where possible was considered crucial. Trial Forge will not be a guideline or a checklist but a 'go to' website for research on randomised trials methods, with a linked programme of applied methodology research, coupled to an effective evidence-dissemination process. Moreover, it will support an informal network of interested trialists who meet virtually (online) and occasionally in person to build capacity and knowledge in the design and conduct of efficient randomised trials.Some of the resources invested in randomised trials are wasted because of limited evidence upon which to base many aspects of design, conduct, analysis, and reporting of clinical trials. Trial Forge will help to address this lack of evidence.

  12. Quality of scintillating fibres after hot bump shrinking

    CERN Document Server

    Rodrigues Cavalcante, Ana Barbara; Joram, Christian

    2016-01-01

    Shrinking the diameter of fibre bumps by a hot drawing tool requires to run the fibre through the hot tool over its full length, bearing the risk of a degradation of the fibre performance. In this study we demonstrated that the hot bump shrinking method has no visible effect on the optical attenuation length, the light yield following ionising radiation, the diameter, the mechanical stability and the integrity of the cladding. For the latter, even a small positive impact was observed.

  13. Job Grading Standard for Machine Tool Operator, WG-3431.

    Science.gov (United States)

    Civil Service Commission, Washington, DC. Bureau of Policies and Standards.

    The standard covers nonsupervisory work involved in the set up, adjustment, and operation of conventional machine tools to perform machining operations in the manufacture and repair of castings, forgings, or parts from raw stock made of various metals, metal alloys, and other materials. A general description of the job at both the WG-8 and WG-9…

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nematzadeh, Fardin [Materials and Energy Research Center, Tehran (Iran, Islamic Republic of); Akbarpour, Mohammad Reza, E-mail: mreza.akbarpour@gmail.com [Materials and Energy Research Center, Tehran (Iran, Islamic Republic of); Kokabi, Amir Hosein; Sadrnezhaad, Seyed Khatiboleslam [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2009-12-15

    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 {gamma} 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.

  16. 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.

  17. Non-isothermal FEM analyses of large-strain back extrusion forging

    Energy Technology Data Exchange (ETDEWEB)

    Flower, E.C.; Hallquist, J.O.; Shapiro, A.B.

    1986-06-19

    Back extrusion forging is a complex metal forming operation dominated by large-strain, non-isothermal deformation. NIKE2D, a fully vectorized implicit finite-element program developed at Lawrence Livermore National Laboratory, was applied to a two-stage isothermal back extrusion forging process. Modeling of the forging process required special features in the FEM code such as friction and interactive rezoning that allows for remeshing of the distorted mesh while maintaining a complete history of all the state variables. To model conditions of the non-isothermal forging process required implementing TOPAZ2D, our LLNL-developed two-dimensional implicit finite element code for heat conduction analysis, as a subroutine into NIKE2D. The fully coupled version maintains all the original features of both codes and can account for the contribution of heat generation during plastic deformation. NIKE/TOPAZ-2D was applied to the piercing operation of the back extrusion forging process. The thermal deformation history of the die, punch, and workpiece and the effective plastic strains were calculated.

  18. 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.

  19. Forging of Naval Brass (ASTM B16) - Finite Element Analysis using Ls Dyna

    Science.gov (United States)

    Subha Sankari, T.; Sangavi, S.; Paneerselvam, T.; Venkatraman, R.; Venkatesan, M.

    2016-09-01

    Forging is one of the important manufacturing process in which products like connecting rod, transmission shaft, clutch hubs and gears are produced. Finite element analysis (FEA) in forming techniques is of recent interest for the optimal design and determination of right manufacturing forming process. The data from the numerical results can help in providing the information for selecting the ideal process conditions. Thus aside from experimental values, simulation by the finite element analysis software's such as LS DYNA can be used for the analysis of strain distribution in forging processes. In the present work, Finite element simulation of open die forging of naval brass (ASTM B16) is done at an optimal temperature. An advanced multi physics simulation software package by the Livermore software technology cooperation LSTC - LS DYNA is utilized for the simulation of forging process. For the forging validation, experiment is conducted with a cylindrical billet having height 45 mm and diameter of 40mm. The numerical results are compared with that of experimental results carried out at the same temperature and dimensions for validation. The distribution of strain is analyzed. Energy analysis due to impact load is detailed. The simulation results are found to be in good agreement with the experimental results.

  20. Filling Rules of Bevel Gears in the Closed-die Cold Forging

    Institute of Scientific and Technical Information of China (English)

    Huamin LIU; Liangju HUANG; Shenhua YANG; Shihong ZHANG

    2005-01-01

    The closed-died cold forging technology of the bevel gears used in Jada car was investigated. With the analysis of the strain field and velocity field of the plastic deformation and the endured forces of the dies, the filling rules forthe metal were analyzed by the elastic-plastic finite element method (FEM). The results show that there is a great difference among closed-die cold forging, extrusion and forging, as far as the metal flowing is concerned. The outer addendum cannot be filled completely in the closed-die cold forging of the bevel gears, and the round angle will be formed. But it does not influence the application of the bevel gears. At the beginning, the rigid area is formed in the cavity of the lower die. And then it will move upwards to supply the metal for the gear filling. For the closed-die cold forging of the bevel gears, the force acting on the upper die and the lower die is significantly different.

  1. Retained Austenite Decomposition and Carbide Formation During Tempering a Hot-Work Tool Steel X38CrMoV5-1 Studied by Dilatometry and Atom Probe Tomography

    Science.gov (United States)

    Lerchbacher, Christoph; Zinner, Silvia; Leitner, Harald

    2012-12-01

    The microstructural development of a hot-work tool steel X38CrMoV5-1 during continuous heating to tempering temperature has been investigated with the focus on the decomposition of retained austenite (Stage II) and carbide formation (Stages III and IV). Investigations have been carried out after heating to 673.15 K, 773.15 K, 883.15 K (400 °C, 500 °C, 610 °C) and after a dwell time of 600 seconds at 883.15 K (610 °C). Dilatometry and atom probe tomography were used to identify tempering reactions. A distinctive reaction takes place between 723.15 K and 823.15 K (450 °C and 550 °C) which is determined to be the formation of M3C from transition carbides. Stage II could be evidenced with the atom probe results and indirectly with dilatometry, indicating the formation of new martensite during cooling. Retained austenite decomposition starts with the precipitation of alloy carbides formed from nanometric interlath retained austenite films which are laminary arranged and cause a reduction of the carbon content within the retained austenite. Preceding enrichment of substitutes at the matrix/carbide interface in the early stages of Cr7C3 alloy carbide formation could be visualised on the basis of coarse M3C carbides within the matrix. Atom probe tomography has been found to be very useful to complement dilatational experiments in order to characterise and identify microstructural changes.

  2. 基于Forge2D/3D的阀体胎模锻模拟分析%Simulation of Die-forging for Valve Based on Forge 2D/3D

    Institute of Scientific and Technical Information of China (English)

    康海鹏

    2012-01-01

    采用Forge 2D/3D有限元分析模拟软件,设计阀体胎模和坯料;经过模拟分析了成型过程中坯料的温度变化、整体的应力、应变、金属的流动趋势和流线分布等;通过生产验证了胎模和坯料设计的合理性和工艺的可行性.%The die and billet of a valve was designed by Forge 2D/3D software. The temperature, stress, strain, and metal flow trend of billet during the simulation was analyzed; the rationality of die, billet design and feasibility of process was validated by production.

  3. FE Simulation Modelling and Exergy Analysis of Conventional Forging Deformation Behaviour of Material Processing

    Directory of Open Access Journals (Sweden)

    Santosh Sanodiya

    2017-03-01

    Full Text Available The present paper examines the deformation behaviour of geometrical specimens of an aluminium alloy undergoing axial compression in a Universal Testing Machine under dry condition. It is observed that researchers have made attempts to investigate alternate specimens for friction calibration. It is found that ring compression test is recommended as the standard test for determination of coefficient of friction, because it gives reliable results. The effect of weight percentage of silicon carbide on microstructure, hardness and upsetting load is studied. The friction factor at die metal interface is evaluated by ring compression tests and its effect on non-uniform deformation is investigated. The experimental results are finally compared with those obtained by FEA simulation and modelling. In order to validate the predictability of these specimens, real experiments on them are carried out. Rings of standard dimensional ratio 6:3:1 in the same machine. Friction predictions from both specimen are found to be in close match, proposed alternate specimen offers a powerful tool for friction prediction in the absence of ring specimen. Some aspects of Exergy calculations have been in the past repeatedly used to quantify the quality and quantity of energy used in thermal energy processes. This attempt to drive a exergy utilization and compare for the first time two entirely different manufacturing processes, material processing by a mechanical method of straining of the material and thermal processing during cold forging of the same mass of the material using exergy formulation as metric. The exergy analysis of material processing is determined by performed work and utilized heat transfer using mechanical and thermal processes

  4. Comparison between hobbed and precision forged helical gears for automobile manual transaxle - on the prospect of form, precision, material specification and production cost

    Energy Technology Data Exchange (ETDEWEB)

    Ooka, M.; Kawasaki, Y.; Hoguchi, T.; Tsujimoto, H.; Yamazaki, S.; Yoshinaga, M. [O-oka Co., Toyota (Japan); Moriwaki, I. [Kyoto Inst. of Tech. (Japan); Kagaya, C. [Chubu Univ., Kasugai (Japan)

    2005-07-01

    This paper describes the comparison between hobbed and forged helical gears in terms of precision, deformation of heat-treatment, material specification and production cost. With the results the forged ones are superior to hobbed ones. (orig.)

  5. Application of geometric midline yield criterion to analysis of three-dimensional forging

    Institute of Scientific and Technical Information of China (English)

    ZHAO De-wen; WANG Gen-ji; LIU Xiang-hua; WANG Guo-dong

    2008-01-01

    A kinematically admissible continuous velocity field was proposed for the analysis of three-dimensional forging. The linear yield criterion expressed by geometric midline of error triangle between Tresca and Twin shear stress yield loci on the π-plane, called GM yield criterion for short, was firstly applied to analysis of the velocity field for the forging. The analytical solution of the forging force with the effects of external zone and bulging parameter is obtained by strain rate inner product. Compression tests of pure lead are performed to compare the calculated results with the measured ones. The results show that the calculated total pressures are higher than the measured ones whilst the relative error is no more than 9.5%. It is implied that the velocity field is reasonable and the geometric midline yield criterion is available. The solution is still an upper-bound one.

  6. 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.

  7. 论最小锻比%Statement of the Minimum Forging Ratio

    Institute of Scientific and Technical Information of China (English)

    任猛; 钱莉丽; 杜锦; 江盛龙

    2015-01-01

    The forging ratio is just a macro indicator and only shows the shape change of the forging cross section. The determinant parameters such as the anvil width ratio and reduction which influence on the inner deformation will be controlled and the acceptable products will be obtained with minimum forging ratio.%锻比作为一个宏观指标,只代表锻件所经历的截面形状变化。合理控制砧宽比、压下量等对内部变形起决定性作用的参数,可以在小锻比条件下生产合格产品。

  8. Finite element simulation of stretch forging using a mesh condensation method

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to reduce the computation time of finite element simulations of stretch forging process,a mesh condensation method is presented and applied to a three-dimensional rigid-viscoplastic finite element program.In this method,a conventional mesh for the whole zone of a workpiece is condensed to a computational mesh for the active deformation zone.Two vital problems are solved,which are automatic construction of the computational mesh and treatment of interfaces between the deformation zone and the rigid zone.The mesh condensation method is compared with conventional finite element method by simulations of a six-bite stretch forging process.Some simulation results including forging load,temperature distribution and effective strain distribution are illustrated.The efficiency and accuracy of this method are verified.

  9. Heuristic algorithm for planning and scheduling of forged pieces heat treatment

    Directory of Open Access Journals (Sweden)

    R. Lenort

    2012-04-01

    Full Text Available The paper presents a heuristic algorithm for planning and scheduling of forged pieces heat treatment which allows maximizing the capacity exploitation of the heat treatment process and the entire forging process. Five Focusing Steps continuous improvement process was selected as a methodological basis for the algorithm design. Its application was supported by simulation experiments performed on a dynamic computer model of the researched process. The experimental work has made it possible to elicit the general rules for planning and scheduling of the heat treatment process of forged pieces which reduce losses caused by equipment conversion and setup times, and which increase the throughput of this process. The HIPO diagram was used to design the algorithm.

  10. Multi-objective optimization of gear forging process based on adaptive surrogate meta-models

    Science.gov (United States)

    Meng, Fanjuan; Labergere, Carl; Lafon, Pascal; Daniel, Laurent

    2013-05-01

    In forging industry, net shape or near net shape forging of gears has been the subject of considerable research effort in the last few decades. So in this paper, a multi-objective optimization methodology of net shape gear forging process design has been discussed. The study is mainly done in four parts: building parametric CAD geometry model, simulating the forging process, fitting surrogate meta-models and optimizing the process by using an advanced algorithm. In order to maximally appropriate meta-models of the real response, an adaptive meta-model based design strategy has been applied. This is a continuous process: first, bui Id a preliminary version of the meta-models after the initial simulated calculations; second, improve the accuracy and update the meta-models by adding some new representative samplings. By using this iterative strategy, the number of the initial sample points for real numerical simulations is greatly decreased and the time for the forged gear design is significantly shortened. Finally, an optimal design for an industrial application of a 27-teeth gear forging process was introduced, which includes three optimization variables and two objective functions. A 3D FE nu merical simulation model is used to realize the process and an advanced thermo-elasto-visco-plastic constitutive equation is considered to represent the material behavior. The meta-model applied for this example is kriging and the optimization algorithm is NSGA-II. At last, a relatively better Pareto optimal front (POF) is gotten with gradually improving the obtained surrogate meta-models.

  11. HotSpot Software Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Walker, H; Homann, S G

    2009-03-12

    This Software Test Plan (STP) describes the procedures used to verify and validate that the HotSpot Health Physics Codes meet the requirements of its user base, which includes: (1) Users of the PC version of HotSpot conducting consequence assessment, hazard assessment and safety analysis calculations; and (2) Users of the NARAC Web and iClient software tools, which allow users to run HotSpot for consequence assessment modeling. This plan is intended to meet Critical Recommendation 2 from the Software Evaluation of HotSpot and DOE Safety Software Toolbox Recommendation for inclusion of HotSpot in the Department of Energy (DOE) Safety Software Toolbox. These users and sponsors of the HotSpot software and the organizations they represent constitute the intended audience for this document. HotSpot software is maintained for the Department of Energy Office of Emergency Operations by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL). An overview of HotSpot and NARAC are provided.

  12. HotSpot Software Configuration Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Walker, H; Homann, S G

    2009-03-12

    This Software Configuration Management Plan (SCMP) describes the software configuration management procedures used to ensure that the HotSpot dispersion model meets the requirements of its user base, which includes: (1) Users of the PC version of HotSpot for consequence assessment, hazard assessment and safety analysis calculations; and (2) Users of the NARAC Web and iClient software tools, which allow users to run HotSpot for consequence assessment modeling These users and sponsors of the HotSpot software and the organizations they represent constitute the intended audience for this document. This plan is intended to meet Critical Recommendations 1 and 3 from the Software Evaluation of HotSpot and DOE Safety Software Toolbox Recommendation for inclusion of HotSpot in the Department of Energy (DOE) Safety Software Toolbox. HotSpot software is maintained for the Department of Energy Office of Emergency Operations by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL). An overview of HotSpot and NARAC are provided.

  13. Simulative Testing of Friction and Lubrication in Cold Forging of Steel and Aluminum

    DEFF Research Database (Denmark)

    Ceron, Ermanno; Bay, Niels; Aida, Tetsuo

    2012-01-01

    A new, simulative test of friction and lubrication in cold forging is developed by the authors. The test is based on a backward can extrusion process in which the workpiece rotates relatively to the conical punch. An analytical model is presented determining the friction stress from the measured ...... coating plus MoS2 and single bathe lubrication with PULS and aluminum provided with 6 different lubricant systems. The new test is so severe, that it is possible to break down the best lubrication systems for cold forging of steel and aluminum....

  14. An upper bound solution for closed die sinter forging of hexagonal shapes

    Indian Academy of Sciences (India)

    R K Ranjan; S Kumar

    2004-06-01

    The paper reports on an investigation into the various aspects of closed die cold forging of hexagonal powder preforms, which have been compacted and sintered from atomized powder. It is found that for certain dimensional ratios of the preform, the die pressure is minimum. An attempt has been made determine the die pressures developed during the closed die forging of the hexagonal powder preform by using an upper bound approach. The results so obtained are discussed critically to illustrate the interaction of various process parameters involved and are presented graphically.

  15. Trial Production of Drum Forgings%鼓轮锻件的生产试制

    Institute of Scientific and Technical Information of China (English)

    张广森; 张成霞; 陈国红; 黄冬凤; 刘垒; 丁宝平

    2013-01-01

    The abnormity cylinder forgings with big taper and small height is produced successfully by blanking with top flat anvil and bottom V shaped anvil , which lays the foundation to manufacture nuclear power tapered cylinder forgings.%采用上平、下V型砧制坯,成功生产了锥度大、高度小的异形筒体锻件,为公司在核电锥形筒体锻件生产方面打下了基础。

  16. 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.

  17. High speed forging of solid powder discs of large slenderness ratio

    Indian Academy of Sciences (India)

    R K Ranjan; S Kumar

    2004-10-01

    The paper reports an investigation into the forging of a solid powder circular disc with large slenderness ratio (L/D) between two flat dies at high speed. The deformation pattern during the operation is influenced by many factors, which interact with one another in a complex manner. The decisive factors are the interfacial conditions, initial relative density of the preform and the geometry of the preform. An attempt has been made to determine the die pressures developed during such forging, using an upper bound approach. The results so obtained are presented graphically and discussed critically to illustrate the interaction of various process parameters involved.

  18. 复杂锻件的坯料预成形优化设计方法%Optimum Design Approach for Preform of Complicated Forging Blank

    Institute of Scientific and Technical Information of China (English)

    杨知硕; 刘东; 罗子健; 高国杰

    2012-01-01

    To improve calculation efficiency for preform of complicated forging blank, an optimum design approach was proposed based on numerical simulation and orthogonal design. The numerical simulation was used as computing tool and orthogonal design was employed as optimization mean in the proposed approach. Thus optimization process was separatated from FEM calculation. Applying the approach to optimum design of preform blank for cartridge receiver forging, excellent optimum results were obtained. The influence degree and influence trend of design variables on objective function were defined. The proposed approach is of great value to optimum design for preform of complicated forging blank.%为了提高复杂锻件坯料预成形设计的计算效率,提出了一种基于数值模拟和正交设计相结合的坯料预成形优化设计方法.这种方法以数值模拟为计算工具、以正交设计为优化手段,将优化过程与有限元计算分离开.将此方法应用于某机匣锻件预成形坯料优化设计,获得了良好的效果,确定了各设计变量对目标函数的影响程度和影响趋势.所提出的方法对复杂锻件的坯料预成形优化设计具有重要意义.

  19. Numerical simulation of hot stamping of side impact beam

    Institute of Scientific and Technical Information of China (English)

    Guo Yihui; Ma Mingtu; Fang Gang; Song Leifeng; Liu Qiang; Wang Xiaona; Zhou Dianwu

    2012-01-01

    Ls-DYNA software is adopted to conduct research of numerical simulation on hot stamping of side impact beam to calculate the temperature field distribution, stress field distribution, forming limit diagram (FLD) figure, etc. in the course of hot stamping so as to predict and analyze the formability of parts. ProCAST software is employed to conduct research of numerical simulation on solid quenching course concerning hot stamping to calculate temperature field distri- bution of tools and component of muhiple stamping cycles. The results obtained from numerical simulation can provide significant reference value to hot stamping part design, formability predication and tools cooling system design.

  20. Adjustable broaching tool for tolerance compensation in precision manufacturing

    Directory of Open Access Journals (Sweden)

    Nielsen Emil

    2015-01-01

    Full Text Available Current manufacturing of precision tools for machining typically requires processes such as grinding, EDM or laser processing in order to comply with high requirements on tolerances. However even tools manufactured by these processes come short, when a new batch of workpieces are supplied, and their tolerances are not compliant. This approach presents a precision broaching tool for adjusting the inner diameter of an external broach. The tool compensates for the manufacturing tolerance chain of tool and workpieces by up to 37 μm. The approach is based on conventional shrink fitting of cold forging tools. A numerical and analytical model of the compression is compared with experimental results.

  1. Hot-dome anemometry

    Science.gov (United States)

    Thompson, Brian E.

    1998-05-01

    Hot-dome anemometry obtains three components of flow velocity using an array of sensors, specifically five hot films in the present contribution, which are mounted around the hemispherical tip of a cylindrical support. Calibration for speed and angle resembles that of hot wires and split films except that the procedures accommodate heat transfer dominated by forced convection from the surface of a sphere rather than single or multiple cylinders. Measurements are obtained with hot domes, conventional hot wires, and impact probes in the wake of a wing to quantify measurement uncertainties.

  2. Characterization of Cracking and Crack Growth Properties of the C5A Aircraft Tie-Box Forging

    Science.gov (United States)

    Piascik, Robert S.; Smith, Stephen W.; Newman, John A.; Willard, Scott A.

    2003-01-01

    Detailed destructive examinations were conducted to characterize the integrity and material properties of two aluminum alloy (7075-T6) horizontal stabilizer tie box forgings removed.from US. Air Force C5A and C5B transport aircraft. The C5B tie box forging was,found to contain no evidence of cracking. Thirteen cracks were found in the CSA,forging. All but one of the cracks observed in the C5A component were located along the top cap region (one crack was located in the bottom cap region). The cracks in the C5A component initiated at fastener holes and propagated along a highly tunneled intergranular crack path. The tunneled crack growth configuration is a likelv result of surface compressive stress produced during peening of the .forging suijace. The tie box forging ,fatigue crack growth, fracture and stress corrosion cracking (SCC) properties were characterized. Reported herein are the results of laboratory air ,fatigue crack growth tests and 95% relative humidity SCC tests conducted using specimens machined from the C5A ,forging. SCC test results revealed that the C5A ,forging material was susceptible to intergranular environmental assisted cracking: the C5A forging material exhibited a SCC crack-tip stress-intensity factor threshold of less than 6 MPadn. Fracture toughness tests revealed that the C5A forging material exhibited a fracture toughness that was 25% less than the C5B forging. The C5A forging exhibited rapid laboratory air fatigue crack growth rates having a threshold crack-tip stress-intensity factor range of less than 0.8 MPa sup m. Detailed fractographic examinations revealed that the ,fatigue crack intergranular growth crack path was similar to the cracking observed in the C5A tie box forging. Because both fatigue crack propagation and SCC exhibit similar intergranular crack path behavior, the damage mechanism resulting in multi-site cracking of tie box forgings cannot be determined unless local cyclic stresses can be quantified.

  3. 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…

  4. 76 FR 8773 - Forged Stainless Steel Flanges From India and Taiwan

    Science.gov (United States)

    2011-02-15

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Forged Stainless Steel Flanges From India and Taiwan AGENCY: United States International Trade... steel flanges from India and Taiwan would be likely to lead to continuation or recurrence of...

  5. 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.

  6. Tribo-thermal fatigue of the steel used for the forging die construction

    Science.gov (United States)

    Drumeanu, A. C.

    2017-02-01

    Frequently the durability of the forging dies is firstly determined by the non-isothermal fatigue wear, which causes the cracks appearance on their internal surfaces, much more before their abrasion wear to reach the limit value. In these conditions it is necessary to design the forging dies firstly by the point of view of the non-isothermal fatigue wear. For a correctly choosing and using of metallic material, it is necessary to determine their intrinsic characteristics regarding its cyclic non-isothermal stresses durability. The experimental determination of these characteristics implies a lot of experiments, which are done in specific conditions, different from those used for isothermal mechanical fatigue durability determination. The paper presents the experimental results concerning intrinsic characteristic determination of the forging dies steel. Based on these results there were determined specific equations which characterize this kind of stresses, and the diagrams that represent their graphic image. These data can be used both in designing and exploitation of the forging dies.

  7. Jernberg Industries, Inc: Forging Facility Uses Plant-Wide Assessment to Aid Conversion to Lean Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-10-01

    Jernberg Industries conducted a plant-wide assessment while converting to lean manufacturing at a forging plant. Seven projects were identified that could yield annual savings of $791,000, 64,000 MMBtu in fuel and 6 million kWh.

  8. 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...

  9. 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…

  10. Evaluation of Subsequent Heat Treatment Routes for Near-β Forged TA15 Ti-Alloy

    Directory of Open Access Journals (Sweden)

    Zhichao Sun

    2016-10-01

    Full Text Available TA15 Ti-alloy is widely used to form key load-bearing components in the aerospace field, where excellent service performance is needed. Near-β forging technology provides an attractive way to form these complicated Ti-alloy components but subsequent heat treatment has a great impact on the final microstructure and mechanical properties. Therefore evaluation and determination of the heat treatment route is of particular significance. In this paper, for the near-β forged TA15 alloy, the formation and evolution of microstructures under different subsequent heat treatment routes (annealing, solution and aging, toughening and strengthening were studied and the cooling mode after forging was also considered. Then, the type and characteristics of the obtained microstructures were discussed through quantitative metallographic analysis. The corresponding mechanical properties (tensile, impact toughness, and fracture toughness and effects of microstructural characteristics were investigated. Finally, for a required microstructure and performance a reasonable heat treatment route was recommended. The work is of importance for the application and development of near-β forging technology.

  11. 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...

  12. Preform design optimization for forging process based on the topological approach

    Science.gov (United States)

    Shao, Yong; Lu, Bin; Ou, Hengan; Cui, Zhenshan

    2013-05-01

    Preform design plays an important role in forging design especially for parts with complex shapes. In this paper, an attempt was made to develop a topological approach in the preform design of bulk metal forming processes based on the Bi-direction evolutionary structural optimization (BESO) strategy. In this approach, a new element addition and removal criteria based on the equivalent strain have been proposed for evaluating and optimizing the material flow in the forging process. To obtain a smooth preform boundary, a closed B-spline curve based on the least square approximation algorithm is employed to approximate the uneven surface of updated preform. An inhouse developed C♯ program has been employed to integrate the FE simluation, shape optimsation and surface approximation process. A 2D blade forging perform design problem are evaluate using the developed method. The results suggest that the optimized preform has shown better performance in improving the material flow and deformation uniformity during the forging. The results also demonstrate the robustness and efficiency of the developed preform design optimization method.

  13. Influence of forming velocity on the uniformity of microstructure of semisolid die forging 7075 alloy

    Directory of Open Access Journals (Sweden)

    Jianbo TAN

    2016-12-01

    Full Text Available Liquid phase segregation frequently occurs in the process of semi solid die forging, which makes the parts appear "weak point" or "weak region", and usually, the "weak point" or "weak area" is the reason of crack and service condition failure. In order to analyze the influence factors of the liquid phase segregation of the semi solid die forging, DEFORM-3D is used for the numerical simulation of semi-solid die forging forming process of 7075 aluminum alloy, to study the influence rule of forming velocity on the forming process of cup part. Based on the simulation results, the rheological die forging forming of 7075 aluminum alloythe part is conducted to research the influence of forming velocity on the uniformity of microstructure by means of press machine and cup mould. The simulation and experimental results show that as the filling velocity is faster, the forming process is more unstable; under the condition of head temperature of 400 ℃, the forming pressure of 50 MPa, and the alloy temperature 628 ℃, as the forming velocity increases, the liquid phase segregation degree of cup part increases, and the microstructure is far from uniformity. The segregation degree is up to 18.2% as the forming velocity is 5 mm/s.

  14. 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

  15. Discovery of feature-based hot spots using supervised clustering

    Science.gov (United States)

    Ding, Wei; Stepinski, Tomasz F.; Parmar, Rachana; Jiang, Dan; Eick, Christoph F.

    2009-07-01

    Feature-based hot spots are localized regions where the attributes of objects attain high values. There is considerable interest in automatic identification of feature-based hot spots. This paper approaches the problem of finding feature-based hot spots from a data mining perspective, and describes a method that relies on supervised clustering to produce a list of hot spot regions. Supervised clustering uses a fitness function rewarding isolation of the hot spots to optimally subdivide the dataset. The clusters in the optimal division are ranked using the interestingness of clusters that encapsulate their utility for being hot spots. Hot spots are associated with the top ranked clusters. The effectiveness of supervised clustering as a hot spot identification method is evaluated for four conceptually different clustering algorithms using a dataset describing the spatial distribution of ground ice on Mars. Clustering solutions are visualized by specially developed raster approximations. Further assessment of the ability of different algorithms to yield hot spots is performed using raster approximations. Density-based clustering algorithm is found to be the most effective for hot spot identification. The results of the hot spot discovery by supervised clustering are comparable to those obtained using the G* statistic, but the new method offers a high degree of automation, making it an ideal tool for mining large datasets for the existence of potential hot spots.

  16. Conversion of Rapid Prototyping Models into Metallic Tools by Ceramic Moulding—an Indirect Rapid Tooling Process

    Institute of Scientific and Technical Information of China (English)

    Teresa; P; DUARTE; J; M; FERREIRA; F; Jorge; LINO; A; BARBEDO; Rui; NETO

    2002-01-01

    A process to convert models made by rapid prototypi ng techniques like SL (stereolitography) and LOM (laminated object manufacturing) or by conventional techniques (silicones, resins, wax, etc.) into metallic mould s or tools has been developed. The main purpose of this technique is to rapidly obtain the first prototypes of parts, for plastics injection, forging or any oth er manufacturing process using the tools produced by casting a metal into a cera mic mould. Briefly, it can be said that the ceramic...

  17. Soft ceramics for high temperature lubrication: graphite-free lubricants for hot and warm forging of steel

    NARCIS (Netherlands)

    Gonzalez Rodriguez, Pablo

    2016-01-01

    The main research focus of this thesis is on the development of the next generation of solid lubricants for high temperature forming of steel. These lubricants are based on ceramic nanoparticles which are more resistant to temperature and oxidation than traditional lubricants. Nowadays, the most com

  18. Research on shape anvils for drawing in free hot forging%大锻件锻造拔长砧型

    Institute of Scientific and Technical Information of China (English)

    赵玲玲; 杜凤山; 黄华贵; 安子军

    2009-01-01

    利用有限元软件模拟了V型砧的锻造拔长过程,并对不同夹角的V型砧压下后锻坯塑性变形区内应力、应变的状态进行比较.结果显示,在117°~153°温度范围内,V型角越大,锻坯心部金属获得的变形量越大,但同时锻坯次表层金属的变形程度减小.为此,将V型砧夹角处的V型砧面改为凸型平砧面,提出了梯型砧锻造拔长工艺.结果表明,梯型砧工艺提高了锻坯内部的压应力水平,使锻坯心部和次表层金属同时获得了较大且均匀的变形,有助于扩大锻坯内部孔洞的锻合范围,改善大锻件的内部质量.

  19. Soft ceramics for high temperature lubrication: graphite-free lubricants for hot and warm forging of steel

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.

    2016-01-01

    The main research focus of this thesis is on the development of the next generation of solid lubricants for high temperature forming of steel. These lubricants are based on ceramic nanoparticles which are more resistant to temperature and oxidation than traditional lubricants. Nowadays, the most

  20. Hot Stars Old-Fashioned or Trendy?

    CERN Document Server

    Pauldrach, A W A

    2002-01-01

    Spectroscopic analyses with the intention of the interpretation of the UV-spectra of the brightest stars as individuals - supernovae - or as components of star-forming regions - massive O stars - provide a powerful tool with great astrophysical potential for the determination of extragalactic distances and of the chemical composition of star-forming galaxies even at high redshifts. The perspectives of already initiated work with the new generation of tools for quantitative UV-spectroscopy of Hot Stars that have been developed during the last two decades are presented and the status of the continuing effort to construct corresponding models for Hot Star atmospheres is reviewed. Because the physics of the atmospheres of Hot Stars are strongly affected by velocity expansion dominating the spectra at all wavelength ranges, hydrodynamic model atmospheres for O-type stars and explosion models for Supernovae of Type Ia are necessary as basis for the synthesis and analysis of the spectra. It is shown that stellar par...

  1. Heat Losses Evaluation for Domestic Hot Water Distribution Systems

    Directory of Open Access Journals (Sweden)

    Theodor Mateescu

    2006-01-01

    Full Text Available In sanitary systems assembly, domestic hot water distribution supply networks represent an important weight for energetically balance.par This paper presents, in an analytical and graphical manner, the computational tools needed for domestic hot water piping system behavior characterization in different functional and structural assumptions.

  2. 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.

  3. Effects of Cryogenic Forging and Anodization on the Mechanical Properties of AA 7075-T73 Aluminum Alloys

    Science.gov (United States)

    Shih, Teng-Shih; Liao, Tien-Wei; Hsu, Wen-Nong

    2016-03-01

    In this study, high-strength AA7075 alloy samples were cryogenically forged after annealing and then subjected to solution and aging treatments. The cryogenically forged 7075-T73 alloy samples displayed equiaxed fine grains associated with abundant fine precipitates in their matrix. Compared with conventional 7075-T73 alloy samples, the cryogenically forged samples exhibited an 8-12% reduction in tensile strength and an increased fatigue strength and higher corrosion resistance. The fatigue strength measured at 107 cycles was 225 MPa in the bare samples; the strength was increased to 250 MPa in the cryogenically forged samples. The effect of anodization on the corrosion resistance of the bare samples was improved from (E corr) -0.80 to -0.61 V.

  4. Fabrication and densification enhancement of SiC-particulate-reinforced copper matrix composites prepared via the sinter-forging process

    Institute of Scientific and Technical Information of China (English)

    Mohammadmehdi Shabani; Mohammad Hossein Paydar; Mohammad Mohsen Moshksar

    2014-01-01

    The fabrication of copper (Cu) and copper matrix silicon carbide (Cu/SiCp) particulate composites via the sinter-forging process was investigated. Sintering and sinter-forging processes were performed under an inert Ar atmosphere. The influence of sinter-forging time, tempera-ture, and compressive stress on the relative density and hardness of the prepared samples was systematically investigated and subsequently com-pared with that of the samples prepared by the conventional sintering process. The relative density and hardness of the composites were enhanced when they were prepared by the sinter-forging process. The relative density values of all Cu/SiCp composite samples were observed to decrease with the increase in SiC content.

  5. Effects of Process Parameters on Deformation and Temperature Uniformity of Forged Ti-6Al-4V Turbine Blade

    Science.gov (United States)

    Luo, Shiyuan; Zhu, Dahu; Hua, Lin; Qian, Dongsheng; Yan, Sijie; Yu, Fengping

    2016-11-01

    This work is motivated by the frequent occurrence of macro- and microdefects within forged Ti-6Al-4V turbine blades due to the severely nonuniform strain and temperature distributions. To overcome the problem of nonuniformity during the blade forging operation, firstly, a 2D coupled thermo-mechanical finite element approach using the strain-compensated Arrhenius-type constitutive model is employed to simulate the real movements and processing conditions, and its reliability is verified experimentally. Secondly, two evaluation indexes, standard deviation of equivalent plastic strain and standard deviation of temperature, are proposed to evaluate the uniformity characteristics within the forged blade, and the effects of four process parameters including the forging velocity, friction factor, initial workpiece temperature and dwell time on the uniformity of strain and temperature distributions are carefully studied. Finally, the numerically optimized combination of process parameters is validated by the application in a practical process. The parametric study reveals that a reasonable combination of process parameters considering the flow resistance, flow localization and the effects of deformation and friction heating is crucial for the titanium alloy blade forging with uniformity. This work can provide a significant guidance for the design and optimization of blade forging processes.

  6. Numerical simulation and experimental study for the die forging process of a high-speed railway brake disc hub

    Science.gov (United States)

    Sun, Mingyue; Xu, Bin; Zhang, Long; LI, Dianzhong

    2013-05-01

    With the aim of manufacturing a near-net shape forging product of a brake disk hub for the high-speed railway, the die forging process was designed and optimized in this study. Firstly, based on the measured stress-strain curves at different strain rates and the thermal-physical parameters of 40Cr A steel, a finite element model for the forging process of a high-speed railway brake disc hub was established. Then, the temperature, stress and strain fields were studied and analyzed at the pre-forging and the finial-forging stages. Besides, in order to trace the stress and strain evolution, five points at different positions were chosen on the billet, and the comparison of the state conditions was made among these points. The results have demonstrated that the product can be well formed by an elaborately designed three-stage forging process, which may reduce the metal machine allowance and the producing cost effectively. Finally, an industrial trial was made and a machined product with sound quality was obtained.

  7. 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

    A new, simulative test of friction and lubrication in cold forging is developed by the authors. The test is based on a backward can extrusion process in which the workpiece rotates. An analytical model is presented determining the friction stress from the measured torque during testing combined...... 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....

  8. Volume calculation of the spur gear billet for cold precision forging with average circle method

    Institute of Scientific and Technical Information of China (English)

    Wangjun Cheng; Chengzhong Chi; Yongzhen Wang; Peng Lin; Wei Liang; Chen Li

    2014-01-01

    Forging spur gears are widely used in the driving system of mining machinery and equipment due to their higher strength and dimensional accuracy. For the purpose of precisely calculating the volume of cylindrical spur gear billet in cold precision forging, a new theoretical method named average circle method was put forward. With this method, a series of gear billet volumes were calculated. Comparing with the accurate three-dimensional modeling method, the accuracy of average circle method by theoretical calculation was estimated and the maximum relative error of average circle method was less than 1.5%, which was in good agreement with the experimental results. Relative errors of the calculated and the experimental for obtaining the gear billet volumes with reference circle method are larger than those of the average circle method. It shows that average circle method possesses a higher calculation accuracy than reference circle method (traditional method), which should be worth popularizing widely in calculation of spur gear billet volume.

  9. Fatigue life on a full scale test rig: Forged versus cast wind turbine rotor shafts

    Science.gov (United States)

    Herrmann, J.; Rauert, T.; Dalhoff, P.; Sander, M.

    2016-09-01

    To reduce uncertainties associated with the fatigue life of the highly safety relevant rotor shaft and also to review today's design practice, the fatigue behaviour will be tested on a full scale test rig. Until now tests on full scale wind turbine parts are not common. Therefore, a general lack of experience on how to perform accelerated life time tests for those components exists. To clarify how to transfer real conditions to the test environment, the arrangements and deviations for the upcoming experimental test are discussed in detail. In order to complete investigations of weight saving potentials, next to getting a better comprehension of the fatigue behaviour by executing a full scale test, a further outcome are suggestions for the usage of cast and forged materials regarding the fatigue and the remaining life of the rotor shaft. It is shown, that it is worthwhile to think about a material exchange for the forged rotor shaft.

  10. Study of Dynamic Characteristics for Hydraulic System on 300MN Die-forging Press

    Science.gov (United States)

    Chen, Guoqiang; Tan, Jianping

    2017-06-01

    The faults such as seal breakdown and pressure sensor damage occur in 300MN Die-forging press frequently. First, the fault phenomenon and harm of the hydraulic system was compiled statistics, the theoretical analysis of the hydraulic impact of hydraulic system are carried out based on the momentum theorem; Then, the co-simulation model of hydraulic system was established by AMESim and Simulink software and the correctness was verified. Finally, the dynamic characteristics of hydraulic system for the key working condition “forging stroke changing to mold collision” was analyzed, the influences rules of system parameters such as the leak gap of valve, diameter of water way pipeline, emulsion temperature and air contain act on hydraulic system are obtained. This conclusions have a theoretical guiding significance to the improvement and maintains of high pressure and large flow hydraulic system.

  11. Effect of multiaxial forging on microstructure and mechanical properties of Mg-o.8Ca alloy

    Science.gov (United States)

    Yurchenko, N. Yu; Stepanov, N. D.; Salishchev, G. A.; Rokhlin, L. L.; Dobatkin, S. V.

    2014-08-01

    It was shown that multiaxial forging with continuous decrease of temperature from 450°C to 250°C turns coarse structure of the Mg-0.8Ca alloy in homogenized state with grain size of several hundreeds gm into fine structure with average grain size of about 2.1 gm. Refinement of structure is accompanied by drastic increase of mechanical properties: tensile yield strength increases from 50 MPa to 193 MPa, ultimate tensile strength increases from 78 to 308 MPa and elongation to fracture increases from 3.0% to 7.2%. The microstructural evolution during multiaxial forging is studied using optical microscopy, scanning electron microscopy and EBSD analysis. The mechanisms responsible for refinement of microstructure are discussed

  12. Effect of interfacial friction during forging of solid powder discs of large slenderness ratio

    Indian Academy of Sciences (India)

    R K Ranjan; S Kumar

    2004-10-01

    The paper reports an investigation into the effect of interfacial friction law during the forging of a powder circular disc with large slenderness ratio (L/D) between two flat dies. The deformation pattern during the operation is influenced by many factors, which interact with each other in a complex manner. The relative velocity between the work piece material and the die surface, together with high interfacial pressure and/or deformation modes, creates the conditions essential for adhesion in addition to sliding. The decisive factors are the interfacial conditions, initial relative density of the preform and geometry of the preform. An attempt has been made to determine the most realistic interfacial friction law and die pressures developed during such forging using an upper bound approach. The results so obtained are presented graphically and discussed critically to illustrate the interaction of various interfacial friction laws involved.

  13. Die Motions of New Forging Process Using IntermediateDie Assembly

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The die motions of a new forging process for automation with an intermediate die assembly called hamburger were analyzed through high-speed video pictures. The results showed that the upper die that is assembled in the hamburger and retained over the lower die collides few times with the ram and workpiece, but sound products can be obtained with less sticking in spite of the lowered impacts of hit.

  14. GRAIN GROWTH MODEL OF INCONEL 718 ALLOY FORGED SLAB IN REHEATING PROCESS PRIOR TO ROUGH ROLLING%Inconel 718合金方坯粗轧加热过程晶粒长大模型

    Institute of Scientific and Technical Information of China (English)

    陈礼清; 隋凤利; 刘相华

    2009-01-01

    The Inconel 718 superalloy is extensively used to manufacture critical parts in aero-nautical, astronautical, oil and chemical industries due to its excellent mechanical, physical and anti-corrosion behavior. Usually, these parts are shaped by hot forging or rolling in open-train mills. Recently, the tandem hot rolling has been applied to form superalloy bar products. In some cases, it can replace the traditional rolling, since it has higher productivity and product quality. In order to obtain the most favorable microstructure and the best mechanical properties of Inconel 718 alloy in tandem hot rolling, it is necessary to control its microstructural evolution in every step of the whole rolling process. With the aid of computer modeling, it is possible to make such a controlling process possible. As the first step in tandem hot rolling, reheating process of a forged slab prior to rough rolling plays a predominant role in predicting the grain size change or even the microstructural evo-lution. Thus, in this study, an Inconel 718 alloy forged slab was used as the experimental material and the effects of reheating temperature and holding time on its grain growth were investigated. A universal model was developed and verified for the grain growth of Inconel 718 alloy forged slab in reheating process prior to rough rolling. With the increase of holding time, the grain size shows no remarkable change up to 1173 K. The grain growth presents a linear trend in the range from 1173 to 1323 K. A parabolic trend of grain growth can be observed when reheating temperature is higher than 1323 K. The established grain growth model of Inconel 718 alloy would be suitable to calculate the grain size evolution under the both isothermal and non-isothermal reheating conditions. This could also provide a basis in formulating the technological parameters for tandem hot rolling of Inconel 718 superalloy.%以Inconel 718合金锻坯为研究对象,在1173-1423 K的温度范围内,研究

  15. Forming limit prediction of powder forging process by the energy-based elastoplastic damage model

    Science.gov (United States)

    Yeh, Hung-Yang; Cheng, Jung-Ho; Huang, Cheng-Chao

    2004-06-01

    An energy-based elastoplastic damage model is developed and then applied to predict the deformation and fracture initiation in powder forging processes. The fracture mechanism is investigated by the newly proposed damage model, which is based on the plastic energy dissipation. The developed formulations are implemented into finite element program ABAQUS in order to simulate the complex loading conditions. The forming limits of sintered porous metals under various operational conditions are explored by comparing the relevant experiments with the finite element analyses. The sintered iron-powder preforms of various initial relative densities (RDs) and aspect ratios are compressed until crack initiates. The deformation level of the bulged billets at fracture stroke obtained from compressive fracture tests is utilized to validate the finite element model and then the forming limit diagrams are constructed with the validated model. This model is further verified by the gear blank forging. The fracture site and corresponding deformation level are predicted by the finite element simulations. Meanwhile, the gear forging experiment is performed on the sintered preforms. The predicted results agree well with the experimental observations.

  16. Computer-assisted Rheo-forging Processing of A356 Aluminum Alloys

    Science.gov (United States)

    Kim, H. H.; Kang, C. G.

    2010-06-01

    Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. In order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of A356 aluminum molten state. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D V6.1. Samples of metal parts were subsequently fabricated by using hydraulic press machinery. In order to compare the influence of loading method, two types of samples were fabricated: (1) samples fabricated under direct loading die sets (2) those fabricated under indirect loading die sets. The formability and defects, which were predicted by FEM simulation, were similar to those of samples used in practice.

  17. 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

  18. Hot stamping advanced manufacturing technology of lightweight car body

    CERN Document Server

    Hu, Ping; He, Bin

    2017-01-01

    This book summarizes the advanced manufacturing technology of original innovations in hot stamping of lightweight car body. A detailed description of the technical system and basic knowledge of sheet metal forming is given, which helps readers quickly understand the relevant knowledge in the field. Emphasis has been placed on the independently developed hot stamping process and equipment, which help describe the theoretical and experimental research on key problems involving stress field, thermal field and phase transformation field in hot stamping process. Also, a description of the formability at elevated temperature and the numerical simulation algorithms for high strength steel hot stamping is given in combination with the experiments. Finally, the book presents some application cases of hot stamping technology such as the lightweight car body design using hot stamping components and gradient hardness components, and the cooling design of the stamping tool. This book is intended for researchers, engineers...

  19. Transmission electron microscopy of aged Ti-10Mo-20Nb alloy after hot swaging; Microscopia eletronica de transmissao da liga Ti-10Mo-20Nb envelhecida apos forjamento a quente

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Sinara Borborema, E-mail: sinarab@msn.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Baldan, Renato, E-mail: renatobaldan@gmail.com [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia; Torres, Juliana; Oliveira, Nathalia Rodrigues, E-mail: juliana_torres_5@hotmail.com, E-mail: nathalia_roliveira@yahoo.com.br [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil); Nunes, Carlos Angelo; Mei, Paulo Roberto, E-mail: cnunes@demar.eel.usp.br, E-mail: pmei@fem.unicamp.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil)

    2014-08-15

    Ti alloys are widely used in biomedical applications. Within this class, metastable β -Ti alloys stand, because through thermomechanical processing it is possible to obtain mechanical properties and in particular one suitable Young's modulus for biomedical applications. These alloys require high mechanical strength and a low Young's modulus to avoid stress shielding. Preliminary studies showed that the microstructure of the Ti-10Mo- 20Nb alloy after cold forging and aging 500 °C/24 h consisted in bimodal distribution of α phase in the β matrix. The aim of this study was to characterize the microstructure of Ti-10Mo-20Nb alloy after hot forging and aging at 500 °C for 24 hours. Microstructural characterization consisted of analyzes by X-ray diffraction and transmission electron microscopy. According to the results, while the cold forging resulted in a bimodal α distribution in the β matrix, hot forging resulted in a thin and homogeneous α precipitation in the β matrix. (author)

  20. Hot plasma dielectric tensor

    NARCIS (Netherlands)

    Westerhof, E.

    1996-01-01

    The hot plasma dielectric tensor is discussed in its various approximations. Collisionless cyclotron resonant damping and ion/electron Bernstein waves are discussed to exemplify the significance of a kinetic description of plasma waves.

  1. Influence on the quality of forgings long-axis heavy forgings in squaring process%压方圆角对长轴类大锻件质量影响研究

    Institute of Scientific and Technical Information of China (English)

    李光喜; 吴玉忠; 郭扬

    2015-01-01

    According to the characteristics of long-axis heavy forgings.The whole forging process of longaxis heavy forging was divided into three steps,including squaring,stretching and chamfering rounding.Researches of forging process are now focused on the optimization of stretching,but hardly on forging process optimization.By means of DEFORM-3D software,edge radius of V-shaped anvil were simulated and optimized from aspects of internal stress state,stress and the damage factor in squaring process.Results of Simulation show that appropriate edge radius of V-shaped anvil can prevent forging cracks and improve the quality of forgings.%长轴类大锻件的锻造过程一般分为压方、拔长和倒棱滚圆三大步骤,目前对锻造工艺研究较多的是拔长和倒棱滚圆的优化,很少有对压方工艺优化的研究。本文从V型砧边缘的圆角半径的大小来对长轴类大锻件的压方过程进行模拟优化,从锻件内部应力、应变及破坏因子三个方面进行对比分析。结果表明,适当增大V型砧边缘的圆角半径可以有效防止锻件裂纹的产生,为锻件的质量提高和结构设计提供一种有效、可靠的分析方法。

  2. Hot deformation behavior and flow stress model of F40MnV steel

    Institute of Scientific and Technical Information of China (English)

    WANG Jin; CHEN Jun; ZHAO Zhen; RUAN Xue-yu

    2007-01-01

    Single hit compression tests were performed at 1 223-1 473 K and strain rate of 0.1-10 s-1 to study hot deformation behavior and flow stress model of F40MnV steel. The dependence of the peak stress, initial stress, saturation stress, steady state stress and peak stain on Zener-Hollomon parameter were obtained. The mathematical models of dynamic recrystallization fraction and grain size were also obtained. Based on the tested data.the flow stress model of F40MnV steel was established in dynamic recovery region and dynamic recrystallization region, respectively. The results show that the activation energy for dynamic recrystallization is 278.6 kJ/mol by regression analysis. The flow stress model of F40MnV steel is proved to approximate the tested data and suitable for numerical simulation of hot forging.

  3. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  4. 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

  5. Effects of minor yttrium addition on hot deformability of lamellar Ti-45Al-5Nb alloy

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-yong; LI Bao-hui; KONG Fan-tao

    2007-01-01

    The effects of 0.3%(molar fraction, the same below) yttrium addition on hot deformability of lamellar Ti-45Al-5Nb alloy were investigated by simulated isothermal forging tests. The ingots with the nominal compositions of Ti-45Al-5Nb and Ti-45Al-5Nb-0.3Y were prepared by induction skull melting. Simulated isothermal forging tests were conducted on Gleeble 1500D thermo-simulation machine using a 6 mm in diameter and 10 mm in length compressive specimen at the deformation temperatures of 1 100, 1 150, 1 200 ℃ and strain rates of 1.0, 0.1, 0.01 s-1. The results show that yttrium addition remarkably improves hot deformability of Ti-45Al-5Nb alloy. An appropriate hot deformation processing parameter of Ti-45Al-5Nb-0.3Y alloy is determined as 1 200 ℃, 0.01 s-1. The flow stresses are decreased by yttrium addition under the same compressive conditions. The activation energies of deformation Q are calculated as 448.6 and 399.5 kJ/mol for Y-free and Y-containing alloys, respectively. The deformed microstructure observation under 1 200 ℃, 0.01 s-1 condition indicates that Ti-45Al-5Nb-0.3Y alloy shows more dynamic recrystallization. The improvement of hot deformability of Ti-45Al-5Nb-0.3Y alloy induced by yttrium addition should be attributed to that the smaller the original lamellar colonies, the lower the deformation resistance and activation energy of deformation are, and the more the dynamic recrystallization is.

  6. Hot Isostatic Pressing Technology for Defence and Space Applications

    Directory of Open Access Journals (Sweden)

    G. Appa Rao

    2012-01-01

    Full Text Available Hot isostatic pressing (HIP technology has been established for the development of AISI-304 stainless steel and nickel base superalloy Inconel 718 integral turbine rotors, for liquid propulsion engine of Prithvi missile, and cryoengine of geostationary satellite launch vehicle (GSLV, respectively. Before making the full size rotors, the structure – property relationships in hot isostatic pressed (HIPed 304 stainless steel and superalloy 718 were established. The HIPed steel and superalloy have shown near 100 per cent theoretical density, homogeneous, and fine grained microstructure. Their mechanical properties were found to be in agreement with those specified for the integral turbine rotors and hence, development of full size near net shaped integral turbine rotors was undertaken. The HIPed steel rotors subjected to the static engine tests have shown a satisfactory performance, and therefore a large number of rotors could be produced to fulfill the requirement of target labs. The HIP technology for the integral turbine rotors was found to be cost effective (about 50 per cent over the conventional fabrication method which involves forging, machining, and welding of blades to the disk. The processing, structure, and properties of the HIPed 304 stainless steel and superalloy 718 in relation to the performance of integral turbine rotors for missile and space vehicle applications are discussed in this paper.Defence Science Journal, 2012, 62(1, pp.73-80, DOI:http://dx.doi.org/10.14429/dsj.62.372

  7. Forging the link between nuclear reactions and nuclear structure

    Science.gov (United States)

    Dickhoff, W. H.

    2016-06-01

    A review of the recent applications of the dispersive optical model (DOM) is presented. Emphasis is on the nonlocal implementation of the DOM that is capable of describing ground-state properties accurately when data like the nuclear charge density are available. The present understanding of the role of short- and long-range physics in determining proton properties near the Fermi energy for stable closed-shell nuclei has relied mostly on data from the (e, e' p) reaction. Hadronic tools to extract such spectroscopic information have been hampered by the lack of a consistent reaction description that provides unambiguous and undisputed results. The DOM, conceived by Claude Mahaux, provides a unified description of both elastic nucleon scattering and structure information related to single-particle properties below the Fermi energy. We have recently introduced a nonlocal dispersive optical potential for both the real and imaginary part. Nonlocal absorptive potentials yield equivalent elastic differential cross sections for 40Ca as compared to local ones but change the l-dependent absorption profile suggesting important consequences for the analysis of nuclear reactions. Below the Fermi energy, nonlocality is essential for an accurate representation of particle number and the nuclear charge density. Spectral properties implied by (e, e' p) and (p, 2p) reactions are correctly described, including the energy distribution of about 10% high-momentum protons obtained at Jefferson Lab. The nonlocal DOM allows a complete description of experimental data both above (up to 200 MeV) and below the Fermi energy in 40Ca. It is further demonstrated that elastic nucleon-nucleus scattering data constrain the spectral strength in the continuum of orbits that are nominally bound in the independent-particle model. Extension of this analysis to 48Ca allows a prediction of the neutron skin of this nucleus that is larger than most predictions made so far.

  8. Forging the link between nuclear reactions and nuclear structure

    Directory of Open Access Journals (Sweden)

    Dickhoff W. H.

    2016-01-01

    Full Text Available A review of the recent applications of the dispersive optical model (DOM is presented. Emphasis is on the nonlocal implementation of the DOM that is capable of describing ground-state properties accurately when data like the nuclear charge density are available. The present understanding of the role of short- and long-range physics in determining proton properties near the Fermi energy for stable closed-shell nuclei has relied mostly on data from the (e, e′ p reaction. Hadronic tools to extract such spectroscopic information have been hampered by the lack of a consistent reaction description that provides unambiguous and undisputed results. The DOM, conceived by Claude Mahaux, provides a unified description of both elastic nucleon scattering and structure information related to single-particle properties below the Fermi energy. We have recently introduced a nonlocal dispersive optical potential for both the real and imaginary part. Nonlocal absorptive potentials yield equivalent elastic differential cross sections for 40Ca as compared to local ones but change the l-dependent absorption profile suggesting important consequences for the analysis of nuclear reactions. Below the Fermi energy, nonlocality is essential for an accurate representation of particle number and the nuclear charge density. Spectral properties implied by (e, e′ p and (p, 2p reactions are correctly described, including the energy distribution of about 10% high-momentum protons obtained at Jefferson Lab. The nonlocal DOM allows a complete description of experimental data both above (up to 200 MeV and below the Fermi energy in 40Ca. It is further demonstrated that elastic nucleon-nucleus scattering data constrain the spectral strength in the continuum of orbits that are nominally bound in the independent-particle model. Extension of this analysis to 48Ca allows a prediction of the neutron skin of this nucleus that is larger than most predictions made so far.

  9. 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.

  10. 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.

  11. Effects of Low Temperature on Hydrogen-Assisted Crack Growth in Forged 304L Austenitic Stainless Steel

    Science.gov (United States)

    Jackson, Heather; San Marchi, Chris; Balch, Dorian; Somerday, Brian; Michael, Joseph

    2016-08-01

    The objective of this study was to evaluate effects of low temperature on hydrogen-assisted crack propagation in forged 304L austenitic stainless steel. Fracture initiation toughness and crack-growth resistance curves were measured using fracture mechanics specimens that were thermally precharged with 140 wppm hydrogen and tested at 293 K or 223 K (20 °C or -50 °C). Fracture initiation toughness for hydrogen-precharged forgings decreased by at least 50 to 80 pct relative to non-charged forgings. With hydrogen, low-temperature fracture initiation toughness decreased by 35 to 50 pct relative to room-temperature toughness. Crack growth without hydrogen at both temperatures was microstructure-independent and indistinguishable from blunting, while with hydrogen microcracks formed by growth and coalescence of microvoids. Initiation of microvoids in the presence of hydrogen occurred where localized deformation bands intersected grain boundaries and other deformation bands. Low temperature additionally promoted fracture initiation at annealing twin boundaries in the presence of hydrogen, which competed with deformation band intersections and grain boundaries as sites of microvoid formation and fracture initiation. A common ingredient for fracture initiation was stress concentration that arose from the intersection of deformation bands with these microstructural obstacles. The localized deformation responsible for producing stress concentrations at obstacles was intensified by low temperature and hydrogen. Crack orientation and forging strength were found to have a minor effect on fracture initiation toughness of hydrogen-supersaturated 304L forgings.

  12. Application of the genetic algorithm for optimisation of large solar hot water systems

    NARCIS (Netherlands)

    Loomans, M.G.L.C.; Visser, H.

    2002-01-01

    An implementation of the genetic algorithm in a design support tool for (large) solar hot water systems is described. The tool calculates the yield and the costs of solar hot water systems based on technical and financial data of the system components. The genetic algorithm allows for optimisation o

  13. Application of the genetic algorithm for optimisation of large solar hot water systems

    NARCIS (Netherlands)

    Loomans, M.G.L.C.; Visser, H.

    2002-01-01

    An implementation of the genetic algorithm in a design support tool for (large) solar hot water systems is described. The tool calculates the yield and the costs of solar hot water systems based on technical and financial data of the system components. The genetic algorithm allows for optimisation

  14. IR Hot Wave

    Energy Technology Data Exchange (ETDEWEB)

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  15. Hot Air Engines

    Directory of Open Access Journals (Sweden)

    P. Stouffs

    2011-01-01

    Full Text Available Invented in 1816, the hot-air engines have known significant commercial success in the nineteenth century, before falling into disuse. Nowadays they enjoy a renewed interest for some specific applications. The "hot-air engines" family is made up of two groups: Stirling engines and Ericsson engines. The operating principle of Stirling and Ericsson engines, their troubled history, their advantages and their niche applications are briefly presented, especially in the field of micro-combined heat and power, solar energy conversion and biomass energy conversion. The design of an open cycle Ericsson engine for solar application is proposed. A first prototype of the hot part of the engine has been built and tested. Experimental results are presented.

  16. 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.

  17. Derivation of uranium residual radioactive material guidelines for the Aliquippa Forge site

    Energy Technology Data Exchange (ETDEWEB)

    Monette, F.; Jones, L.; Yu, C.

    1992-09-01

    Residual radioactive material guidelines for uranium were derived for the Aliquippa Forge site in Aliquippa, Pennsylvania. This site has been identified for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy (DOE). The uranium guidelines were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the Aliquippa Forge site should not exceed a dose of 100 mrem/yr following decontamination. The DOE residual radioactive material guideline computer code, RESRAD, which implements the methodology described in the DOE manual for implementing residual radioactive material guidelines, was used in this evaluation. Four potential scenarios were considered for the site; the scenarios vary with regard to time spent at the site, sources of water used, and sources of food consumed. The results of the evaluation indicate that the basic dose limit of 100 mrem/yr will not be exceeded for uranium within 1,000 years, provided that the soil concentration of combined uranium (uranium-234, uranium-235, and uranium-238) at the Aliquippa Forge site does not exceed the following levels: 1,700 pCi/g for Scenario A (industrial worker: the expected scenario); 3,900 pCi/g for Scenario B (recreationist: a plausible scenario); 20 pCi/g for Scenario C (resident farmer using well water as the only water source: a possible but unlikely scenario), and 530 pCi/g for Scenario D (resident farmer using a distant water source not affected by site conditions as the only water source: a possible but unlikely scenario). The uranium guidelines derived in this report apply to the combined activity concentration of uranium-234, uranium-235, and uranium-238 and were calculated on the basis of a dose of 100 mrem/yr.

  18. 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.)

  19. 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.

  20. 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...... conditions. The presentation is supported by finite element modelling using an in-house developed computer program and the overall investigation shows that better results in closure of centerline defects are obtained with a V-shaped die with 120º die angle....

  1. Die Electrode Designing and Manufacturing for the Rotary Forging Process of Spiral Bevel Gear%螺旋锥齿轮摆辗成形凹模电极的设计与制造

    Institute of Scientific and Technical Information of China (English)

    史双喜

    2011-01-01

    螺旋锥齿轮摆辗成形凹模通常采用电火花加工,用于电火花加工的电极对于模具型腔的制造精度具有重要影响.对螺旋锥齿轮与工具电极尺寸传递规律进行研究,并在此基础上设计凹模工具电极.最后对设计的电极齿形进行加工和检测,为齿轮摆辗成形凹模电极设计制造提供了科学依据.%The rotary forging process die of spiral bevel gear usually uses EDM, the electrode been used in EDM has the important influence to the mold cavity manufacture precision. In this article, the law of size transfer between spiral bevel gear and tool electrode was researched, and based on this, the tool electrode of die was designed. The processing and testing of electrode tooth shape had been completed, which provided a scientific basis to design and manufacture die electrode for the rotary forging process of spiral bevel gear.

  2. Investigation of Design and Manufacture in Hot Stamping Tools with Conformal Cooling Channels Based on Simulation and 3D-printing Technology%基于数值模拟和3D打印的热冲压模具随形水道设计制造研究

    Institute of Scientific and Technical Information of China (English)

    贺斌; 李显达; 胡平; 司阳磊; 盈亮; 张向奎

    2016-01-01

    To against the uneven cooling of traditional hot stamping tool with opposite deep-hole drilling cooling system, a new design method of hot stamping tool with conformal cooling channels is put forward, which is based on multi-field couplings in heat transfer theory and simulated by Star-ccm+. By taking the insert of a B-pillar tool on the self-developed rainbow electric car as the research object and comparing the cooling effects of traditional hole drilling and some newly proposed cooling designs, a new optimization strategy for B-pillar tool insert with longitudinal conformal cooling channel arrangement is applied and the temperature distribution of work surface before and after optimization has been analyzed. Hot stamping tool with conformal cooling channels is fabricated by means of combining 3D printing technique of precoated sand with traditional sand casting. This hot stamping tool with optimized longitudinal conformal design overcome the cooling limitations of parallel conformal designs, such as maximum temperature of work surface decreases by 47.4%, average temperature decreases by 40.9% and temperature uniformity improves by 1.8%. According to the design process of longitudinal conformal cooling channel, the parameters of channel shape and location such asR, H, rare set as optimization variables and the surface temperature field will serve as the optimization object. The optimization result shows that the maximum temperature of work surface decreases by 49.8%, and the average temperature decreases by 46.8%, and the temperature standard deviation decreases by 67.5%, while the temperature uniformity increases by 1.9%. It is found that this hot stamping tool with conformal cooling channels upgrades production efficiency and prolongs service life-span, furthermore, the uniformity of mechanical properties of hot stamping parts is improved.%针对传统热冲压模具深孔对钻冷却系统冷却不均的现象,基于热冲压过程的多场耦合传热理

  3. Investigations into Deformation Characteristics during Open-Die Forging of SiCp Reinforced Aluminium Metal Matrix Composites

    Directory of Open Access Journals (Sweden)

    Deep Verma

    2013-01-01

    Full Text Available The deformation characteristics during open-die forging of silicon carbide particulate reinforced aluminium metal matrix composites (SiCp AMC at cold conditions are investigated. The material was fabricated by liquid stir casting method in which preheated SiC particles were mixed with molten LM6 aluminium casting alloy and casted in the silicon mould. Finally, preforms obtained were machined in required dimensions. Two separate cases of deformation, that is, open-die forging of solid disc and solid rectangular preforms, were considered. Both upper bound theoretical analysis and experimental investigations were performed followed by finite element simulation using DEFORM, considering composite interfacial friction law, barreling of preform vertical sides, and inertia effects, that is, effect of die velocity on various deformation characteristics like effective stress, strain, strain rate, forging load, energy dissipations, and height reduction. Results have been presented graphically and critically investigated to evaluate the concurrence among theoretical, experimental, and finite element based computational findings.

  4. 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.

  5. Ultrasonic Hot Embossing

    Directory of Open Access Journals (Sweden)

    Werner Karl Schomburg

    2011-05-01

    Full Text Available Ultrasonic hot embossing is a new process for fast and low-cost production of micro systems from polymer. Investment costs are on the order of 20.000 € and cycle times are a few seconds. Microstructures are fabricated on polymer foils and can be combined to three-dimensional systems by ultrasonic welding.

  6. What's Hot? What's Not?

    Science.gov (United States)

    Buczynski, Sandy

    2006-01-01

    When Goldilocks finds three bowls of porridge at different temperatures in the three bears' house, she accurately assesses the situation and comes up with one of the most recognizable lines in children's literature," This porridge is too hot; this porridge is too cold; aahh, this porridge is just right!" Goldilocks' famous line is a perfect…

  7. Hot house bad house

    OpenAIRE

    Azzopardi, Shaun

    2014-01-01

    Shaun Azzopardi met up with a team of researchers led by Eur. Ing. Charles Yousif to take the concrete block to the next level. It is more exciting than it sounds. Photography by Dr Edward Duca. http://www.um.edu.mt/think/hot-house-bad-house/

  8. Fending Off Hot Money

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Amid uncertainties about the amount of hot money,the government strives to curb the harmful capital The benchmark Shanghai Composite Index was plagued by dips, climbs and dives as the stock market slumped from 3,186 to 2,838 points

  9. Selection of the optimal hard facing (HF technology of damaged forging dies based on cooling time t8/5

    Directory of Open Access Journals (Sweden)

    D. Arsić

    2016-01-01

    Full Text Available In exploitation, the forging dies are exposed to heating up to very high temperatures, variable loads: compressive, impact and shear. In this paper, the reparatory hard facing of the damaged forging dies is considered. The objective was to establish the optimal reparatory technology based on cooling time t8/5 . The verification of the adopted technology was done by investigation of the hard faced layers microstructure and measurements of hardness within the welded layers’ characteristic zones. Cooling time was determined theoretically, numerically and experimentally.

  10. Experimental Research on the SizeMeasurement of the High Temperature ForgingBased on Multicolor CCD Technology

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    In order to determine the size measurement accuracy of the high temperature forging's multicolor CCD image by using computerprograms, this paper obtained the high temperature forging's CCD image by multicolor CCD camera and its fact size by thevernier caliper on the forging field, and then measured the size of the high temperature forging from its CCD image, compared thesize from the CCD image and the size from the vernier caliper, the result shows that the measurement accuracy satisfied theindustrial production.

  11. 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.

  12. A Study On The Fabrication Of Iron Powder From Forging Scale Using Hydrogen

    Directory of Open Access Journals (Sweden)

    Shin S.M.

    2015-06-01

    Full Text Available This study was conducted to investigate the effect of hydrogen content, temperature, reaction time for the reduction of forging scale which is mainly composed of hematite (Fe2O3. All reductive reactions were performed over the temperature range of 700 to 1200°C as well as 0.1 to 1 atm of hydrogen partial pressures. The results showed that the mechanism for the reduction of iron oxides using hydrogen gas was not a simple process, but proceeded in multiple reduction stages thermodynamically. The iron oxide was almost completely reduced to metallic iron powder with 91 wt.% of iron content in the forging scale at 0.1 atm of hydrogen partial pressure. The content of iron was however found to be increased with increasing hydrogen partial pressure from 0.1 to 1 atm with regardless of temperatures. The metallic iron powder was obtained with the mean size of 100 μm and more porous structure was observed.

  13. Standard method of macroetch testing steel bars, billets, blooms, and forgings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 Macroetching, which is the etching of specimens for macrostructural examination at low magnifications, is a frequently used technique for evaluating steel products such as bars, billets, blooms, and forgings. 1.2 Included in this method is a procedure for rating steel specimens by a graded series of photographs showing the incidence of certain conditions. The method is limited in application to bars, billets, blooms, and forgings of carbon and low alloy steels. 1.3 A number of different etching reagents may be used depending upon the type of examination to be made. Steels react differently to etching reagents because of variations in chemical composition, method of manufacture, heat treatment and many other variables. Establishment of general standards for acceptance or rejection for all conditions is impractical as some conditions must be considered relative to the part in which it occurs. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is ...

  14. A Method For Producing Hollow Shafts By Rotary Compression Using A Specially Designed Forging Machine

    Directory of Open Access Journals (Sweden)

    Tomczak J.

    2015-09-01

    Full Text Available The paper presents a new method for manufacturing hollow shafts, where tubes are used as billet. First, the design of a specially designed forging machine for rotary compression is described. The machine is then numerically tested with regard to its strength, and the effect of elastic strains of the roll system on the quality of produced parts is determined. The machine’s strength is calculated by the finite element method using the NX Nastran program. Technological capabilities of the machine are determined, too. Next, the results of the modeling of the rotary compression process for a hollow stepped shafts by the finite element method are given. The process for manufacturing hollow shafts was modeled using the Simufact.Forming simulation program. The FEM results are then verified experimentally in the designed forging machine for rotary compression. The experimental results confirm that axisymmetric hollow shafts can be produced by the rotary compression method. It is also confirmed that numerical methods are suitable for investigating both machine design and metal forming processes.

  15. FORGE Canada Consortium: outcomes of a 2-year national rare-disease gene-discovery project.

    Science.gov (United States)

    Beaulieu, Chandree L; Majewski, Jacek; Schwartzentruber, Jeremy; Samuels, Mark E; Fernandez, Bridget A; Bernier, Francois P; Brudno, Michael; Knoppers, Bartha; Marcadier, Janet; Dyment, David; Adam, Shelin; Bulman, Dennis E; Jones, Steve J M; Avard, Denise; Nguyen, Minh Thu; Rousseau, Francois; Marshall, Christian; Wintle, Richard F; Shen, Yaoqing; Scherer, Stephen W; Friedman, Jan M; Michaud, Jacques L; Boycott, Kym M

    2014-06-01

    Inherited monogenic disease has an enormous impact on the well-being of children and their families. Over half of the children living with one of these conditions are without a molecular diagnosis because of the rarity of the disease, the marked clinical heterogeneity, and the reality that there are thousands of rare diseases for which causative mutations have yet to be identified. It is in this context that in 2010 a Canadian consortium was formed to rapidly identify mutations causing a wide spectrum of pediatric-onset rare diseases by using whole-exome sequencing. The FORGE (Finding of Rare Disease Genes) Canada Consortium brought together clinicians and scientists from 21 genetics centers and three science and technology innovation centers from across Canada. From nation-wide requests for proposals, 264 disorders were selected for study from the 371 submitted; disease-causing variants (including in 67 genes not previously associated with human disease; 41 of these have been genetically or functionally validated, and 26 are currently under study) were identified for 146 disorders over a 2-year period. Here, we present our experience with four strategies employed for gene discovery and discuss FORGE's impact in a number of realms, from clinical diagnostics to the broadening of the phenotypic spectrum of many diseases to the biological insight gained into both disease states and normal human development. Lastly, on the basis of this experience, we discuss the way forward for rare-disease genetic discovery both in Canada and internationally.

  16. Hot Fuel Examination Facility (HFEF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Hot Fuel Examination Facility (HFEF) is one of the largest hot cells dedicated to radioactive materials research at Idaho National Laboratory (INL). The nation's...

  17. High Speed Turning of H-13 Tool Steel Using Ceramics and PCBN

    Science.gov (United States)

    Umer, Usama

    2012-09-01

    H-13 is the toughest tool steel used in machined die casting and forging dies. Due to its extreme hardness and poor thermal conductivity high speed cutting results in high temperature and stresses. This gives rise to surface damage of the workpiece and accelerated tool wear. This study evaluates the performance of different tools including ceramics and PCBN using practical finite element simulations and high speed orthogonal cutting tests. The machinability of H-13 was evaluated by tool wear, surface roughness, and cutting force measurements. From the 2D finite element model for orthogonal cutting, stresses and temperature distributions were predicted and compared for the different tool materials.

  18. What Is Hot Yoga (Bikram)?

    Science.gov (United States)

    Healthy Lifestyle Consumer health What is hot yoga? Answers from Edward R. Laskowski, M.D. Hot yoga is a vigorous form of yoga performed in a studio ... you check with your doctor before trying hot yoga if you have any health concerns. If you have heart disease, problems with ...

  19. Forging Ahead

    Science.gov (United States)

    Finkel, Ed

    2017-01-01

    Community colleges always have played an integral role in training workers for infrastructure- and transportation-related fields like truck driving, construction, welding and electrical work. If the $1 trillion infrastructure package proposed by President Donald Trump comes to pass, these fields will grow significantly, at least for a while, which…

  20. Hot Subluminous Stars

    Science.gov (United States)

    Heber, U.

    2016-08-01

    Hot subluminous stars of spectral type B and O are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage. Most hot subdwarf stars are chemically highly peculiar and provide a laboratory to study diffusion processes that cause these anomalies. The most obvious anomaly lies with helium, which may be a trace element in the atmosphere of some stars (sdB, sdO) while it may be the dominant species in others (He-sdB, He-sdO). Strikingly, the distribution in the Hertzsprung-Russell diagram of He-rich versus He-poor hot subdwarf stars of the globular clusters ω Cen and NGC 2808 differ from that of their field counterparts. The metal-abundance patterns of hot subdwarfs are typically characterized by strong deficiencies of some lighter elements as well as large enrichments of heavy elements. A large fraction of sdB stars are found in close binaries with white dwarf or very low-mass main sequence companions, which must have gone through a common-envelope (CE) phase of evolution. Because the binaries are detached they provide a clean-cut laboratory to study this important but yet poorly understood phase of stellar evolution. Hot subdwarf binaries with sufficiently massive white dwarf companions are viable candidate progenitors of type Ia supernovae both in the double degenerate as well as in the single degenerate scenario as helium donors for double detonation supernovae. The hyper-velocity He-sdO star US 708 may be the surviving donor of such a double detonation supernova. Substellar companions to sdB stars have also been found. For HW Vir systems the companion mass distribution extends from the stellar into the brown dwarf regime. A giant planet to the acoustic-mode pulsator V391 Peg was the first discovery of a planet that survived the red giant evolution of its host star. Evidence for Earth-size planets to two pulsating sdB stars have been reported and circumbinary giant planets or brown dwarfs have been found around HW

  1. The hot Hagedorn Universe

    CERN Document Server

    Rafelski, Johann

    2016-01-01

    In the context of the half-centenary of Hagedorn temperature and the statistical bootstrap model (SBM) we present a short account of how these insights coincided with the establishment of the hot big-bang model (BBM) and helped resolve some of the early philosophical difficulties. We then turn attention to the present day context and show the dominance of strong interaction quark and gluon degrees of freedom in the early stage, helping to characterize the properties of the hot Universe. We focus attention on the current experimental insights about cosmic microwave background (CMB) temperature fluctuation, and develop a much improved understanding of the neutrino freeze-out, in this way paving the path to the opening of a direct connection of quark-gluon plasma (QGP) physics in the early Universe with the QCD-lattice, and the study of the properties of QGP formed in the laboratory.

  2. The hot chocolate effect

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Frank S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)

    1982-05-01

    The "hot chocolate effect" was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the ten percent accuracy of the experiments.

  3. Hot chocolate effect

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, F.S.

    1982-05-01

    The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments.

  4. Hot Spring Metagenomics

    Directory of Open Access Journals (Sweden)

    Olalla López-López

    2013-04-01

    Full Text Available Hot springs have been investigated since the XIX century, but isolation and examination of their thermophilic microbial inhabitants did not start until the 1950s. Many thermophilic microorganisms and their viruses have since been discovered, although the real complexity of thermal communities was envisaged when research based on PCR amplification of the 16S rRNA genes arose. Thereafter, the possibility of cloning and sequencing the total environmental DNA, defined as metagenome, and the study of the genes rescued in the metagenomic libraries and assemblies made it possible to gain a more comprehensive understanding of microbial communities—their diversity, structure, the interactions existing between their components, and the factors shaping the nature of these communities. In the last decade, hot springs have been a source of thermophilic enzymes of industrial interest, encouraging further study of the poorly understood diversity of microbial life in these habitats.

  5. Peppery Hot Bean Curd

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Peppery Hot Bean Curd is a famous dish that originated in Chengdu,Sichuan Province.Dating back to the year under the reign of Emperor Tongzhi during the Qing Dynasty(1862-1875),a woman chef named Chen created this dish.In Chinese it is called Mapo Bean Curd. Ingredients:Three pieces of bean curd,100 grams lean pork,25 grams green soy beans or garlic

  6. Hot subluminous stars

    CERN Document Server

    Heber, Ulrich

    2016-01-01

    Hot subluminous stars of spectral type B and O are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage. Strikingly, the distribution in the Hertzsprung-Russell diagram of He-rich vs. He-poor hot subdwarf stars of the globular clusters omega Cen and NGC~2808 differ from that of their field counterparts. The metal-abundance patterns of hot subdwarfs are typically characterized by strong deficiencies of some lighter elements as well as large enrichments of heavy elements. A large fraction of sdB stars are found in close binaries with white dwarf or very low-mass main sequence companions, which must have gone through a common-envelope phase of evolution.They provide a clean-cut laboratory to study this important but yet purely understood phase of stellar evolution. Substellar companions to sdB stars have also been found. For HW~Vir systems the companion mass distribution extends from the stellar into the brown dwarf regime. A giant planet to the pulsator V391 ...

  7. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  8. Jupiter's Hot, Mushy Moon

    Science.gov (United States)

    Taylor, G. Jeffrey

    2003-01-01

    Jupiter's moon Io is the most volcanically active body in the Solar System. Observations by instruments on the Galileo spacecraft and on telescopes atop Mauna Kea in Hawai'i indicate that lava flows on Io are surprisingly hot, over 1200 oC and possibly as much as 1300 oC; a few areas might have lava flows as hot as 1500 oC. Such high temperatures imply that the lava flows are composed of rock that formed by a very large amount of melting of Io's mantle. This has led Laszlo Keszthelyi and Alfred S. McEwen of the University of Arizona and me to reawaken an old hypothesis that suggests that the interior of Io is a partially-molten mush of crystals and magma. The idea, which had fallen out of favor for a decade or two, explains high-temperature hot spots, mountains, calderas, and volcanic plains on Io. If correct, Io gives us an opportunity to study processes that operate in huge, global magma systems, which scientists believe were important during the early history of the Moon and Earth, and possibly other planetary bodies as well. Though far from proven, the idea that Io has a ocean of mushy magma beneath its crust can be tested with measurements by future spacecraft.

  9. Automated Determination of the Power Required and Selection of Electric Motors for Forging Fly-Press Mechanisms

    Directory of Open Access Journals (Sweden)

    K. Karakoulidis

    2015-06-01

    Full Text Available The current work deals with appropriate selection of electric motors for forging fly-press machines. To solve the equation of motion of the electric drive of these mechanisms characterized by impact (pulsating load and presence of flywheel, numerical methods (calculus have been used.

  10. Dynamic strain aging precipitation of Mg17Al12 in AZ80 magnesium alloy during multi-directional forging process

    Science.gov (United States)

    Zhu, Q. F.; Wang, G. S.; Wang, X. J.; Liu, F. Z.; Ban, C. Y.; Cui, J. Z.

    2017-05-01

    Dynamic aging precipitation of Mg17Al12 phases in AZ80 magnesium alloy was studied by multi-directional forging (MDF) with decreasing temperatures from 410 to 300 °C. The results show that the morphology of the dynamically precipitated β-Mg17Al12 phases (formed during forging process) exhibited granular shape. During the multi-directional forging process, the inhomogeneous dynamic precipitation of the β-Mg17Al12 phases result in the coexistence of the fine grains (with many granular Mg17Al12 phases) and coarse grains (without Mg17Al12 phases) in the samples. The fine grains (with many granular Mg17Al12 phases) area expands with the decreasing of final forging temperature. The inhomogenous Al content distribution in the Mg matrix leads to the non-uniform dynamic precipitation of the Mg17Al12 phase. These Mg17Al12 phase retards the growth of the DRX grains, which in turns results in the formation fine grains area during the during the MDF process with temperature decreasing.

  11. 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...

  12. 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... Submission of Transaction Requests Through the Bureau of the Public Debt § 370.40 Can I be held...

  13. 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…

  14. PREFACE: Hot Quarks 2004

    Science.gov (United States)

    Antinori, Federico; Bass, Steffen A.; Bellwied, Rene; Ullrich, Thomas; Velkovska, Julia; Wiedemann, Urs

    2005-04-01

    Why another conference devoted to ultra-relativistic heavy-ion physics? As we looked around the landscape of the existing international conferences and workshops, we realized that there was not a single one tailored to the people who are most directly involved with the actual research work: students, post-docs, and junior faculty/research scientists. Of course there are schools, but that was not what we had in mind. We wanted a meeting where young researchers could come together to discuss in depth the physics that they are working on without any hindrance. The major conferences have very limited time for discussions which is often shared amongst the most established. This leaves little room for young people to ask their questions and to get the detailed feedback which they deserve and which satisfies their curiosity. A discussion-driven workshop, centering on those without whom there will be no future—that seemed like what was needed. And thus the Hot Quarks workshop was born. The aim of Hot Quarks was to enhance the direct exchange of scientific information among the younger members of the community, from both experiment and theory. Participation was by invitation only in order to emphasize the contributions from junior researchers. This approach makes the workshop unique among the many forums in the field. For young scientists it represented an opportunity for exposure that they would not have had in one of the major conferences. The hope is that this meeting has helped to stimulate the next generation of scientists in our field and, at the same time, strengthened their sense of community. It all came together from 18 24 July 2004, when the 77 participants met at The Inn at Snakedance in the Taos Ski Valley, New Mexico, USA, for the first Hot Quarks workshop. Photograph Participants gather in the sunshine at the foot of the Taos Ski Valley chairlift. By all accounts, Hot Quarks 2004 was a great success. Every participant had the opportunity to present her or

  15. PTA锻焊反应器的制造%Fabrication of Forge Welding PTA Reactor

    Institute of Scientific and Technical Information of China (English)

    李艳

    2014-01-01

    The article introduces several key techniques for fabrication of large Cr-Mo steel forge welding reactor in PTA unit. The chemical composition of material should be controlled to improve the anti-tempered embrittlement ability for Cr-Mo steel; the advanced smelting process and forging technique should be used to assure the large forging quality;the cooling process of normalization for Cr-Mo steel head should be optimized to assure the material property;the reasonable welding process should be used to assure the welding quality of thick wall circumferential seam and reduce the fabrication cost;the overlay welding process should be optimized to assure the overlay welding quality in inner surface of reactor. Finally, it is very important for the Cr-Mo steel pressure vessel to use the proper heat treatment procedure.%本文对PTA装置上的大型铬钼钢锻焊反应器,在制造过程中的几个关键技术进行了介绍:控制材料的化学成分提高铬钼钢材料的抗回火脆化能力;采用先进的冶炼工艺和锻造技术保证大型锻件的质量;优化铬钼钢封头正火热处理中的冷却工艺来保证材料的性能指标;采用合理的焊接工艺,既保证了厚壁环焊缝的焊接质量,又降低了制造成本;优化堆焊工艺,保证了反应器内壁的堆焊质量;正确选择热处理规范,对铬钼钢压力容器至关重要。

  16. Recrystallization behavior of Ti40 burn-resistant titanium alloy during hot working process

    Institute of Scientific and Technical Information of China (English)

    Yun-jin Lai; She-wei Xin; Ping-xiang Zhang; Yong-qing Zhao; Fan-jiao Ma; Xiang-hong Liu; Yong Feng

    2016-01-01

    The recrystallization behavior of deformed Ti40 alloy during a heat-treatment process was studied using electron backscatter dif-fraction and optical microscopy. The results show that the microstructural evolution of Ti40 alloy is controlled by the growth behavior of grain-boundary small grains during the heating process. These small grains at the grain boundaries mostly originate during the forging proc-ess because of the alloy’s inhomogeneous deformation. During forging, the deformation first occurs in the grain-boundary region. New small recrystallized grains are separated from the parent grains when the orientation between deformation zones and parent grains exceeds a certain threshold. During the heating process, the growth of these small recrystallized grains results in a uniform grain size and a decrease in the av-erage grain size. The special recrystallization behavior of Ti40 alloy is mainly a consequence of the alloy’s highβ-stabilized elemental con-tent and high solution strength of theβ-grains, which partially explains the poor hot working ability of Ti-V-Cr-type burn-resistant titanium alloys. Notably, this study on Ti40 burn-resistant titanium alloy yields important information related to the optimization of the microstruc-tures and mechanical properties.

  17. Evolution of Microstructure and Texture During Hot Compression of a Ni-Fe-Cr Superalloy

    Science.gov (United States)

    Coryell, S. P.; Findley, K. O.; Mataya, M. C.; Brown, E.

    2012-02-01

    Superalloys are being employed in more extreme conditions requiring higher strength, which requires producers to forge products to finer grain sizes with less grain size variability. To assess grain size, crystallographic texture, and substructure as a function of forging conditions, frictionless uniaxial compression testing characteristic of hot working was performed on INCOLOY 945 (Special Metals Corporation, Huntington, WV), which is a newly developed hybrid of alloys 718 and 925, over a range of temperatures and strain rates. The microstructure and texture were investigated comprehensively using light optical microscopy, electron backscatter diffraction (EBSD), electron channeling contrast imaging (ECCI), and transmission electron microscopy (TEM) to provide detailed insight into microstructure evolution mechanisms. Dynamic recrystallization, nucleated by grain/twin boundary bulging with occasional subgrain rotation, was found to be a dominant mechanism for grain refinement in INCOLOY 945. At higher strain rates, static recrystallization occurred by grain boundary migration. During deformation, duplex slip along {111} planes occurred until a stable fiber compression texture was established. Recrystallization textures were mostly random but shifted toward the compression texture with subsequent deformation. An exception occurred at 1423 K (1150 °C) and 0.001 seconds-1, the condition with the largest fraction of recrystallized grains, where a fiber texture developed, which may be indicative of preferential growth of specific grain orientations.

  18. Recrystallization behavior of Ti40 burn-resistant titanium alloy during hot working process

    Science.gov (United States)

    Lai, Yun-jin; Xin, She-wei; Zhang, Ping-xiang; Zhao, Yong-qing; Ma, Fan-jiao; Liu, Xiang-hong; Feng, Yong

    2016-05-01

    The recrystallization behavior of deformed Ti40 alloy during a heat-treatment process was studied using electron backscatter diffraction and optical microscopy. The results show that the microstructural evolution of Ti40 alloy is controlled by the growth behavior of grain-boundary small grains during the heating process. These small grains at the grain boundaries mostly originate during the forging process because of the alloy's inhomogeneous deformation. During forging, the deformation first occurs in the grain-boundary region. New small recrystallized grains are separated from the parent grains when the orientation between deformation zones and parent grains exceeds a certain threshold. During the heating process, the growth of these small recrystallized grains results in a uniform grain size and a decrease in the average grain size. The special recrystallization behavior of Ti40 alloy is mainly a consequence of the alloy's high β-stabilized elemental content and high solution strength of the β-grains, which partially explains the poor hot working ability of Ti-V-Cr-type burn-resistant titanium alloys. Notably, this study on Ti40 burn-resistant titanium alloy yields important information related to the optimization of the microstructures and mechanical properties.

  19. 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.

  20. Inner-product of strain rate vector through direction cosine in coordinates for disk forging

    Institute of Scientific and Technical Information of China (English)

    ZHAO De-wen; JIN Wen-zhong; WANG Lei; LIU Xiang-hua

    2006-01-01

    A new linear integration for plastic power was proposed. The effective strain rate for disk forging with bulge was expressed in terms of two-dimensional strain rate vector, and then its direction cosines were determined by the ratio of coordinate increments. Furthermore, inner-product of the vector for plastic power was term integrated by term and summed. Thereafter, through a formula for determination of bulge an analytical solution of stress effective factor was obtained. Finally, through compression tests, the calculated results of above formula were compared with those of Avitzur's approximate solution and total indicator readings of the testing machine. It is indicated that the calculated compression forces are basically in agreement with the measured ones if the pass reduction is less than 13.35%.However, when the reduction gets up to 25.34% and 33.12%, the corresponding errors between the calculated and measured results also get up to 6% and 13.5%, respectively.

  1. Grain size and texture changes of magnesium alloy AZ31 during multi-directional forging

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Grain size and texture changes of magnesium alloy AZ31 were studied in multidirectional forging(MDF) under decreasing temperature conditions. MDF was carried out up to large cumulative strains of 4.8 with changing the loading direction during decrease in temperature from pass to pass. MDF can accelerate the uniform development of fine-grained structures and increase the plastic workability at low temperatures. As a result, the MDFed alloy shows excellent higher strength as well as moderate ductility at room temperature even at the grain size below 1 μm. Superplastic flow takes place at 423 K and depends on the anisotropy of MDFed samples. The mechanisms of strain-induced free-grained structure development and of the plastic deformation were discussed in detail.

  2. Development of Iron-based Closed-Cell Foams by Powder Forging and Rolling

    Science.gov (United States)

    Paswan, Dayanand; Mistry, Dhananjay; Sahoo, K. L.; Srivastava, V. C.

    2013-08-01

    In the present investigation, an attempt has been made to develop in situ sandwich Fe-based foams using powder forging and rolling. Several metal carbonates are first studied by thermo gravimetric analysis to find out their suitability to be used as foaming agent for iron-based foams. Barium carbonate is found to be the most promising foaming agent among other suitable options studied such as SrCO3, CaCO3, MgCO3, etc. The effects of process parameters such as precursor composition, sintering temperature, foaming temperature and time, and content of foaming agent have been studied. The microstructural characteristics of the sintered precursor have been studied by means of optical and scanning electron microscopy. It was found that a good pore structure can be obtained using 2-3% C in Fe and 3% BaCO3 as foaming agent and by foaming at around 1350 °C for 3-6 min.

  3. Microstructural evolution of Mg-7Al-2Sn Mg alloy during multi-directional impact forging

    Directory of Open Access Journals (Sweden)

    M.G. Jiang

    2015-09-01

    Full Text Available Multi-directional impact forging (MDIF was applied to a Mg-7Al-2Sn (wt.% Mg alloy to investigate its effect on the microstructural evolution. MDIF process exhibited high grain refinement efficiency. After MDIF 200 passes, the grain size drastically decreased to 20 µm from the initial coarse grains of ~500 µm due to dynamic recrystallization (DRX. Meanwhile, original grain boundaries remained during MDIF and large numbers of fine spherical β-Mg17Al12 particles dynamically precipitated along the original grain boundaries with high Al concentration, acting as effective pinning obstacles for the suppression of DRXed grain growth. Besides, micro-cracks nucleated during MDIF and propagated along the interface between the remained globular or cubic Al-Mn particles and Mg matrix.

  4. New microalloyed steels for heavy duty forgings in cars and trucks

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, J. [CDP Bharat Forge GmbH, Ennepetal (Germany)

    2005-07-01

    CDP Bharat Forge has carried out a substantial alloy and process development on microalloyed steels for controlled cooling. The main focus was put on the introduction of this development into series production of parts that were 100% heat treated before. The R+D-activities resulted in the new grades cdpSo38 and cdpSo40. For the grade cdpSo38 an impact energy of >25J (RT) and an elongation of >14% can be guaranteed for the series production of safety critical chassis parts at a yield strength of >600MPa. For the cdpSo40 a yield strength of >700MPa at 10% elongation can be guaranteed in series production. Two of the biggest truck manufacturers in the world have already changed their steering knuckles from heat treated steels 42CrMo4 and 30MnB5 to the new cdpBF-grades. (orig.)

  5. 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...

  6. Development of Replacements for Phoscoating Used in Forging, Extrusion and Metal Forming Processes

    Energy Technology Data Exchange (ETDEWEB)

    Kerry Barnett

    2003-03-01

    Many forging, extrusion, heading and other metal forming processes use graphite-based lubricants, phosphate coatings, and other potentially hazardous or harmful substances to improve the tribology of the metal forming process. The application of phosphate-based coatings has long been studied to determine if other synthetic ''clean'' lubricants could provide the same degree of protection afforded by phoscoatings and its formulations. So far, none meets the cost and performance objectives provided by phoscoatings as a general aid to the metal forming industry. In as much as phoscoatings and graphite have replaced lead-based lubricants, the metal forming industry has had previous experience with a legislated requirement to change processes. However, without a proactive approach to phoscoating replacement, many metal forming processes could find themselves without a cost effective tribology material necessary for the metal forming process

  7. Finite element simulation on press forging of magnesium alloy AZ31 sheets

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Press forging of rectangular box of magnesium alloy AZ31 sheets was investigated at elevated temperatures.The characteristics of metal flow were analyzed on the basis of finite element method(FEM)and experiments.Effects of friction factor and sidewall thickness on metal flow and boss forming were investigated by FEM.The results indicate that the bosses and the sidewall of the rectangular box are formed unevenly due to the uneven flow of the metal.The increase in friction factor at die/sheet interface improves the metal flow pattem and the efficiency of boss forming,but reduces the sidewall uniformity.Decrease in sidewall thickness enhances boss forming efficiency,whereas the punch load increases in this case.The present work can provide rcasonable parameters and design guideline for the practical press foxing process of magnesium alloy sheets.

  8. 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.

  9. 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.

  10. Sinter-forged YBa sub 2 Cu sub 3 O sub 7-. delta

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Q.; Georgopoulos, P.; Johnson, D.L.; Marcy, H.O.; Kannewurf, C.R.; Hwu, S.J.; Marks, T.J.; Poeppelmeir, K.R.; Song, S.N.; Ketterson, J.B. (Northwestern Univ., Evanston, IL (USA))

    1987-07-01

    High T{sub c} ceramic superconductors, as exemplified by YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}, have recently gained widespread interest in the scientific community. To date, the preparation of this and related materials in powder form has involved, with few exceptions, solid state reaction techniques. The resulting equilibrated powders, which are rather unsinterable, have typically been formed into pellets and fired for subsequent physical measurements. The densities of such pellets are considerably below the theoretical prediction, and the development of more effective sintering processes would clearly be of great importance. In this communication the authors report a technique (sinter-forging) whereby nearly theoretically dense (>95% TD) samples of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} can be produced. Physical measurements revealed strong texturing and preferred crystallite orientation as well as significant anisotropy in the charge transport.

  11. Manufacturing of aluminum alloy ultra-thick plates by multidirectional forging and subsequent rolling

    Institute of Scientific and Technical Information of China (English)

    张辉; 林高用; 彭大暑; 杨立斌; 林启权

    2002-01-01

    A combinatory large deformation model of multidirectional forging and subsequent rolling was proposed for producing high performance aluminum alloy ultra-thick plates.The results show that fine-grain (2~3 μm) structures were obtained when total deformation coefficient λ =32 at 250~350 ℃ under a strain rate of about 0.1 s-1.The development of fine-grained structure can be characterized by the formation of strain-induced high energy dislocation and then transforms into new grain under large deformation at moderate temperature.The very fine secondary particles formed during large deformation play important role in retain the stability of the fine-grained structures.

  12. 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%.

  13. Research of upsetting ratio in forming processes on a three – slides forging press

    Directory of Open Access Journals (Sweden)

    W.S. Weroński

    2006-04-01

    Full Text Available Purpose: The purpose of the presented in this work research was determining the limiting conditions of upsetting in three-slide forging press (TSFP. The free upsetting process and upsetting process in cylindrical impression were analyzed.Design/methodology/approach: The assumed purpose was confirmed in experimental research. For the case of upsetting in cylindrical impression, the research of limiting upsetting coefficients were made for different diameters and impression lengths. Findings: The obtained results showed large variety of limiting upsetting ratio depending on the analyzed impression geometrical parameters. It was stated, that there are 3 phenomena limiting the upsetting process in the die. The main phenomenon is the bar upsetting outside the impression. The upsetting processes in the impression are limited also by bar buckling outside the impression and overlapping inside the impressionResearch limitations/implications: The results of research allowed for stating that, besides the process geometrical parameters, friction conditions and type of the formed material influenced the limiting upsetting coefficients in the cylindrical impression. It is purposeful to make the further research determining quantitative and qualitative dependencies between these factors. Practical implications: The obtained results are the basis for designing of forming processes in TSFP in which the upsetting dominates. Especially it considers the elongated forgings and elongated preforms with thickeningsOriginality/value: The influence of the impression geometrical parameters on the limiting upsetting coefficients for the case of upsetting in cylindrical impression in TSFP has been analyzed in details. The dependencies, which should be used during designing of upsetting processes in TSFP were determined.

  14. 自由锻造液压机的技术现状及设计分析%Technique status and design analysis of free forging hydraulic press

    Institute of Scientific and Technical Information of China (English)

    谢广玉; 李秀珠; 胡海燕

    2013-01-01

    阐述了自由锻造液压机的发展过程和我国锻造压机的技术现状,对自由锻造液压机的几种结构型式和传动方式进行了比较,说明了锻造油压机的技术特点.%The developing process of free forging hydraulic press and technique status in China has been described in the text. Several structural modes and transmission modes of free forging hydraulic press have been compared, and the technical characteristics of forging hydraulic press have been introduced.

  15. Hot bitumen grouting rediscovered

    Energy Technology Data Exchange (ETDEWEB)

    Naudts, A. [ECO Grouting Specialists, Grand Valley, ON (Canada)

    2001-10-01

    The article extols the value of hot bitumen grouting, in conjunction with cement-based grout, as a fast, safe, environmentally-friendly and cost-effective sealant. A major advantage of bitumen grout is that blown bitumen will never wash out. The article discusses the properties and some applications of bitumen grout. A diagram shows an application of bitumen and cement-based grout at a large dam. Examples of preventing water flow in dams, in a coal mine and in a potash mine are also given.

  16. 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

    ... appeal, or if appealed, pending a final and conclusive court decision. The cash deposit rate will remain... of the adverse facts available (AFA) rate applied to TMC's and Huarong's sales of bars/wedges, and the AFA rate applied to TMC's sales of picks/mattocks.\\3\\ On March 11, 2008, the Department filed its...

  17. Optimal Design of Fuel Injector Bodies Forging Die%喷油器体锻模优化设计

    Institute of Scientific and Technical Information of China (English)

    李志广; 刘碧芬; 宋伟民

    2014-01-01

    Objective This study used the fuel injector bodies die forging forming as the research object,analyzed and optimized the design of the forging die structure and size. Methods The original disadvantages of forging die design were a-voided by optimal design of forging die (especially the design optimization of the structure and size of lock, finishing im-pression, flash cave, gate and edge rolling impression, and optimization of the raw materials blanking specification accord-ing to the height of the edge rolling impression). Results The fuel injector body die forging forming process was improved, the metal difficult deformation area and deformation force were reduced, the consumption was reduced by 0. 15 kg/ piece, the rate of qualified products and the forging efficiency (the hammer speed was reduced by 3 ~ 5 times/ piece) were in-creased, the service life of die forging was at least doubled and the cost was reduced. Conclusion The fuel injector bodies forging die finally obtained had compact structure, enough strength and superior performance, which provide powerful refer-ence for the design and actual production of similar forging dies.%目的:以喷油器体模锻成形为研究对象,对锻模结构与尺寸进行分析和优化设计。方法通过优化锻模设计(尤其是优化锁扣、终锻模膛、飞边槽、钳口、滚挤模膛等结构与尺寸设计以及根据滚挤模膛高度尺寸优选原材料下料规格),克服原锻模设计的缺点。结果有效改善了喷油器体的模锻工艺性,减小了难变形区,减小了变形力,减少了原材料消耗0.15 kg /件,提高了合格品率,提高了锻造效率(减少打击次数3~5锤次/件),提高了锻模使用寿命至少1倍,以及降低了锻模与锻件成本等。结论最终获得的喷油器体锻模,结构高紧凑又强度足够,使用性能优越,可为类似锻模设计和实际生产提供了有力的参考依据。

  18. Tools for Material Design and Selection

    Science.gov (United States)

    Wehage, Kristopher

    The present thesis focuses on applications of numerical methods to create tools for material characterization, design and selection. The tools generated in this work incorporate a variety of programming concepts, from digital image analysis, geometry, optimization, and parallel programming to data-mining, databases and web design. The first portion of the thesis focuses on methods for characterizing clustering in bimodal 5083 Aluminum alloys created by cryomilling and powder metallurgy. The bimodal samples analyzed in the present work contain a mixture of a coarse grain phase, with a grain size on the order of several microns, and an ultra-fine grain phase, with a grain size on the order of 200 nm. The mixing of the two phases is not homogeneous and clustering is observed. To investigate clustering in these bimodal materials, various microstructures were created experimentally by conventional cryomilling, Hot Isostatic Pressing (HIP), Extrusion, Dual-Mode Dynamic Forging (DMDF) and a new 'Gradient' cryomilling process. Two techniques for quantitative clustering analysis are presented, formulated and implemented. The first technique, the Area Disorder function, provides a metric of the quality of coarse grain dispersion in an ultra-fine grain matrix and the second technique, the Two-Point Correlation function, provides a metric of long and short range spatial arrangements of the two phases, as well as an indication of the mean feature size in any direction. The two techniques are implemented on digital images created by Scanning Electron Microscopy (SEM) and Electron Backscatter Detection (EBSD) of the microstructures. To investigate structure--property relationships through modeling and simulation, strategies for generating synthetic microstructures are discussed and a computer program that generates randomized microstructures with desired configurations of clustering described by the Area Disorder Function is formulated and presented. In the computer program, two

  19. Improvement of thrust bearing technology and tooling%推力轴承工艺与工装的改进

    Institute of Scientific and Technical Information of China (English)

    郭兆军; 史光龙; 吕国新

    2016-01-01

    In view of the problems in the process of machining thrust bearing such as the backward forging process, big allowance, poor precision and big cutting off width,etc, the forging process was improved, 4 pieces combined forging by free forging were changed to 8 pieces combined forging by rolling forging to reduce the machining allowance and improves the efifciency;workpiece was separated by the blade sawing instead of turning to cut off to Reduces the cutting allowance and end face allowance,save raw materials, improve the machining efifciency and reduce the production cost;sawing machine for the technical reformation, and making the new tooling, which laid a foundation for process improvement.%针对推力轴承加工过程中存在的锻造工艺落后、留量大、精度差、切断宽度大等问题,对锻造工艺进行了改进,由自由锻4件合锻改为碾环锻造8件合锻,减少了加工留量,提高了效率;工件分离由车刀切断改为锯片锯断,减少了切断留量和端面留量,节约了原材料,提高了加工工效,降低了生产成本;对锯床进行了技术改造,并制作了新工装,为工艺改进奠定了基础。

  20. Analysis & Tools to Spur Increased Deployment of “Waste Heat” Rejection/Recycling Hybrid Ground-source Heat Pump Systems in Hot, Arid or Semiarid Climates Like Texas

    Energy Technology Data Exchange (ETDEWEB)

    Masada, Glenn [Univ. of Texas, Austin, TX (United States); Moon, Tess [Univ. of Texas, Austin, TX (United States)

    2013-09-01

    > (2100ft2) residential building and a 4,982m2 (53,628ft2) three-story commercial office building, and it ran 10-15 year simulations. The integrated GHP model and its Simulink platform provided residential data, ranging from seconds to years, and commercial office building data, ranging from minutes to years. A cooling tower model was coupled to the base case integrated GHP model for the residential building and the resulting HGHP system provided a cost-effective solution for the Austin, TX location. Simulations for both the residential and commercial building models were run with varying degrees of SHR (device/system not identified) and the results were found to significantly decrease installation costs, increase heat pump efficiency (lower entering water temperature), and prolong the lifetime of the borehole field. Lifetime cycle costs were estimated from the simulation results. Sensitivity studies on system operating performance and lifetime costs were performed on design parameters, such as construction materials, borehole length, borehole configuration and spacing, grout conductivity, and effects of SHR. While some of the results are intuitive, these studies provided quantitative estimates of improved performance and cost. One of the most important results of this sensitivity study is that overall system performance is very sensitive to these design parameters and that modeling and simulation are essential tools to design cost-effective systems.