WorldWideScience

Sample records for cast-iron pipe joints

  1. 49 CFR 192.275 - Cast iron pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Cast iron pipe. 192.275 Section 192.275... Cast iron pipe. (a) Each caulked bell and spigot joint in cast iron pipe must be sealed with mechanical leak clamps. (b) Each mechanical joint in cast iron pipe must have a gasket made of a...

  2. SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kiran M. Kothari; Gerard T. Pittard

    2005-07-01

    Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. Bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple castiron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs with the pipe in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, minimize excavation, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of old cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct safe repair operations on live mains.

  3. SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kiran M. Kothari; Gerard T. Pittard

    2005-04-01

    Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. The bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple cast-iron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs while the pipe remains in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of old cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct repair operations on live mains. The development effort is divided into eleven tasks. Task 1 (Program Management) and Task 2 (Establishment of Detailed Design Specifications) were completed previously. Task 3 (Design and Fabricate Ratcheting Stainless-Steel Repair Sleeves) has progressed to installing prototype sleeves in test cast-iron pipe segments. Efforts in the current quarter continued to be focused on Tasks 4-8. Highly valuable lessons were learned from field tests of the 4-inch gas pipe repair robot in cast-iron pipe at Public Service Electric & Gas. (These field tests were conducted and reported previously.) Several design issues were identified which need to be implemented in both the small- and large-diameter repair

  4. 77 FR 17119 - Pipeline Safety: Cast Iron Pipe (Supplementary Advisory Bulletin)

    Science.gov (United States)

    2012-03-23

    ... operators of natural gas cast iron distribution pipelines and state pipeline safety representatives. Recent... owners and operators of natural gas cast iron distribution pipelines and state pipeline safety...; October 11, 1991 and ALN-92-02; June 26, 1992) covering the continued use of cast iron pipe in natural...

  5. 铸铁管道胶圈承插接口抗震性能试验研究%Experimental research on seismic capability of cast-iron pipe with rubber gasket joints

    Institute of Scientific and Technical Information of China (English)

    陈春光; 杨庆华; 孔杰; 解晓杰; 廖倩

    2012-01-01

    Ductile cast iron pipe is a tubular product, which is frequently used in city water-supply project. The seismic capability of joints is one of the factors, which must be considered in the design of water-supply network in seismic areas. To study the mechanical parameters of rubber gasket joints, a series of prototype drawing experiment are performed lo investigate the regularity of joints drawing force and the joints displacement. The experimental results show that, rubber gasket joints for ductile cast iron pipe is favorable for earthquake-resistance; the allowed maximum joints displacement is about 3 ~4cm; the joints spring coefficient is between 32N/cm· cm-2 to 125 N/ cm ·cm-2and the maximum resistance is about 45 ~75N/cm2.%铸铁管道是城市供水工程常用的管材,其接口的抗震性能是地震多发地区供水管网设计必须考虑的因素之一.为研究胶圈承插接口的力学性能参数,采用了原型拉拔试验,测定了管道胶圈接口拉拔力与接口变形量,通过试验数据分析,证明了胶圈承插接口具有良好的抗震性能,接头最大允许变形量可达3~4cm,测定出铸铁管胶圈承插接口单位接触面积弹簧系数值在32~125N/(cm·cm2)之间、单位接触面积接头最大抗力为45~75N/cm2.

  6. Reliability and Sensitivity Analysis of Cast Iron Water Pipes for Agricultural Food Irrigation

    Directory of Open Access Journals (Sweden)

    Yanling Ni

    2014-07-01

    Full Text Available This study aims to investigate the reliability and sensitivity of cast iron water pipes for agricultural food irrigation. The Monte Carlo simulation method is used for fracture assessment and reliability analysis of cast iron pipes for agricultural food irrigation. Fracture toughness is considered as a limit state function for corrosion affected cast iron pipes. Then the influence of failure mode on the probability of pipe failure has been discussed. Sensitivity analysis also is carried out to show the effect of changing basic parameters on the reliability and life time of the pipe. The analysis results show that the applied methodology can consider different random variables for estimating of life time of the pipe and it can also provide scientific guidance for rehabilitation and maintenance plans for agricultural food irrigation. In addition, the results of the failure and reliability analysis in this study can be useful for designing of more reliable new pipeline systems for agricultural food irrigation.

  7. Study of biofilm influenced corrosion on cast iron pipes in reclaimed water

    Science.gov (United States)

    Zhang, Haiya; Tian, Yimei; Wan, Jianmei; Zhao, Peng

    2015-12-01

    Biofilm influenced corrosion on cast iron pipes in reclaimed water was systemically studied using the weight loss method and electrochemical impedance spectroscopy (EIS). The results demonstrated that compared to sterile water, the existence of the biofilm in reclaimed water promoted the corrosion process significantly. The characteristics of biofilm on cast iron coupons were examined by the surface profiler, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The bacterial counts in the biofilm were determined using the standard plate count method and the most probable number (MPN). The results demonstrated that the corrosion process was influenced by the settled bacteria, EPS, and corrosion products in the biofilm comprehensively. But, the corrosion mechanisms were different with respect to time and could be divided into three stages in our study. Furthermore, several corresponding corrosion mechanisms were proposed for different immersion times.

  8. 76 FR 5333 - Non-Malleable Cast Iron Pipe Fittings from the People's Republic of China: Preliminary Results of...

    Science.gov (United States)

    2011-01-31

    ... Doing Business 2010: India, by the World Bank. The price list data is contemporaneous with the POR.\\30... Antidumping Duty Order: Non-Malleable Cast Iron Pipe Fittings From the People's Republic of China, 68 FR 16765 (April 7, 2003). \\2\\ See Initiation of Antidumping and Countervailing Duty Administrative Reviews, 75...

  9. Characterisation of the fatigue properties of cast irons used in the water industry and the effect on pipe strength and performance

    International Nuclear Information System (INIS)

    As part of an on going programme to characterise the residual properties and understand the failure mechanisms of in-service grey cast iron water pipes, the fatigue crack propagation behaviour of grey cast iron samples has been studied. Specimens were sourced from three ex-service pipes. For each pipe the microstructure and composition were characterised and the fracture toughness was determined. The fatigue behaviour was investigated in terms of the crack growth rate (da/dN) as a function of the applied stress intensity factor range. Clear differences in the fatigue behaviour of the samples from different pipes were observed. The result from these investigations, which indicate that microstructural differences play a role in mechanical behaviour, will support the development of asset management tools for use in the water industry.

  10. Performance evaluation of cast iron pipe for crude oil and salt water transportation; Avaliacao e desempenho de duto de aco fundido no transporte de petroleo com aguas salgadas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Carlos Alexandre Martins da [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Mainier, Fernando B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil)

    2005-07-01

    The present paper aims to study and to evaluate the performance of casting iron pipe for transportation of salty and produced waters, presented in the oil industry, where salt contents ranging on very large values. The cast iron above mentioned has an yield strength of 23 kg/mm{sup 2}, tensile strength of de 46 kg/mm{sup 2} (minimum) and an elongation of 15%, and contents of some chemical alloys, such as Cr (0,8 -1,3 %), Mn (1,5 % max) and Si (1,%). Nevertheless it is an exploratory study, the dynamic tests of weight loss carried out in laboratory, with specimens machined from a used pipe piece, with salty solution (3,5 % NaCl) aerated media, has shown very promising results, enabling to qualify, satisfactorily, such material for using in transportation and transferring operations of fluids with a high salty contents, such as crude oil. (author)

  11. Special thermite cast irons

    OpenAIRE

    Yu. Zhiguts; I. Kurytnik

    2008-01-01

    The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  12. Special thermite cast irons

    Directory of Open Access Journals (Sweden)

    Yu. Zhiguts

    2008-07-01

    Full Text Available The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  13. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  14. The mutual co-regulation of extracellular polymeric substances and iron ions in biocorrosion of cast iron pipes.

    Science.gov (United States)

    Jin, Juntao; Guan, Yuntao

    2014-10-01

    New insights into the biocorrosion process may be gained through understanding of the interaction between extracellular polymeric substances (EPS) and iron. Herein, the effect of iron ions on the formation of biofilms and production of EPS was investigated. Additionally, the impact of EPS on the corrosion of cast iron coupons was explored. The results showed that a moderate concentration of iron ions (0.06 mg/L) promoted both biofilm formation and EPS production. The presence of EPS accelerated corrosion during the initial stage, while inhibited corrosion at the later stage. The functional groups of EPS acted as electron shuttles to enable the binding of iron ions. Binding of iron ions with EPS led to anodic dissolution and promoted corrosion, while corrosion was later inhibited through oxygen reduction and availability of phosphorus from EPS. The presence of EPS also led to changes in crystalline phases of corrosion products.

  15. Effects of microbial redox cycling of iron on cast iron pipe corrosion in drinking water distribution systems.

    Science.gov (United States)

    Wang, Haibo; Hu, Chun; Zhang, Lili; Li, Xiaoxiao; Zhang, Yu; Yang, Min

    2014-11-15

    Bacterial characteristics in corrosion products and their effect on the formation of dense corrosion scales on cast iron coupons were studied in drinking water, with sterile water acting as a reference. The corrosion process and corrosion scales were characterized by electrochemical and physico-chemical measurements. The results indicated that the corrosion was more rapidly inhibited and iron release was lower due to formation of more dense protective corrosion scales in drinking water than in sterile water. The microbial community and denitrifying functional genes were analyzed by pyrosequencing and quantitative polymerase chain reactions (qPCR), respectively. Principal component analysis (PCA) showed that the bacteria in corrosion products played an important role in the corrosion process in drinking water. Nitrate-reducing bacteria (NRB) Acidovorax and Hydrogenophaga enhanced iron corrosion before 6 days. After 20 days, the dominant bacteria became NRB Dechloromonas (40.08%) with the protective corrosion layer formation. The Dechloromonas exhibited the stronger corrosion inhibition by inducing the redox cycling of iron, to enhance the precipitation of iron oxides and formation of Fe3O4. Subsequently, other minor bacteria appeared in the corrosion scales, including iron-respiring bacteria and Rhizobium which captured iron by the produced siderophores, having a weaker corrosion-inhibition effect. Therefore, the microbially-driven redox cycling of iron with associated microbial capture of iron caused more compact corrosion scales formation and lower iron release. PMID:25150521

  16. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2011-01-01

    White Cast Iron (Ⅰ) White cast iron or ‘white iron' refers to the type of cast iron in which all of the carbon exists as carbide;there is no graphite in the as-cast structure and the fractured surface shows a white colour.White cast iron can be divided in three classes:· Normal white cast iron — this iron contains only C,Si,Mn,P and S,with no other alloying elements.· Low-alloy white cast iron — the total mass fraction of alloying elements is less than 5%.

  17. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Ph.D Liu Jincheng

    2010-01-01

    @@ Note: This book consists of five sections: Chapter 1 Introduction, Chapter 2 Grey Iron, Chapter 3 Spheroidal Graphite Cast Iron, Chapter 4 Vermicular Cast Iron, and Chapter 5 White Cast Iron. CHINA FOUNDRY publishes this book in several parts serially, starting from the first issue of 2009.

  18. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Chapter 3 Spheroidal Graphite Cast Iron(I) Spheroidal Graphite Cast Iron, SG iron in short, refers to the cast iron in which graphite precipitates as spheroidal shape during solidification of liquid iron. The graphite in common commercial cast iron can only be changed from flake to spheroidal shape by spheroidising treatment. Since spheroidal graphite reduces the cutting effect of stress concentration, the metal matrix strength of SG iron can be applied around 70%-90%, thus the mechanical property of SG iron is significantly superior to other cast irons;even the tensile strength of SG iron is higher than that carbon steel.

  19. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2009-01-01

    @@ This book consists of five sections:Chapter 1 Introduction,Chapter 2 Grey Iron,Chapter 3 Ductile Iron,Chapter 4Vermicular Cast Iron,and Chapter 5 White Cast Iron. CHINA FOUNDRY publishs this book in several parts serially,starting from the first issue of 2009.

  20. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang

    2009-01-01

    @@ Preface Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc.

  1. Niobium in gray cast iron

    International Nuclear Information System (INIS)

    The potential for utilization of niobium in gray cast iron is appraised and reviewed. Experiments described in literature indicate that niobium provides structural refinement of the eutectic cells and also promotes pearlite formation. (Author)

  2. Cast iron - a predictable material

    OpenAIRE

    Jorg C. Sturm; Guido Busch

    2011-01-01

    High strength compacted graphite iron (CGI) or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process s...

  3. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2011-01-01

    @@ Vermicular graphite cast iron(VG iron for short in the following sections)is a type of cast iron in which the graphite is intermediate in shape between flake and spheroidal.Compared with the normal flake graphite in grey iron, the graphite in VG iron is shorter and thicker and shows a curved, more rounded shape.Because its outer contour is exactly like a worm, hence it is called vermicular graphite.

  4. Inoculation Effects of Cast Iron

    Directory of Open Access Journals (Sweden)

    E. Fraś

    2012-12-01

    Full Text Available The paper presents a solidification sequence of graphite eutectic cells of A and D types, as well as globular and cementite eutectics. The morphology of eutectic cells in cast iron, the equations for their growth and the distances between the graphite precipitations in A and D eutectic types were analyzed. It is observed a critical eutectic growth rate at which one type of eutectic transformed into another. A mathematical formula was derived that combined the maximum degree of undercooling, the cooling rate of cast iron, eutectic cell count and the eutectic growth rate. One type of eutectic structure turned smoothly into the other at a particular transition rate, transformation temperature and transformational eutectic cell count. Inoculation of cast iron increased the number of eutectic cells with flake graphite and the graphite nodule count in ductile iron, while reducing the undercooling. An increase in intensity of inoculation caused a smooth transition from a cementite eutectic structure to a mixture of cementite and D type eutectic structure, then to a mixture of D and A types of eutectics up to the presence of only the A type of eutectic structure. Moreover, the mechanism of inoculation of cast iron was studied.

  5. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Spheroidal Graphite Cast Iron(Ⅳ) 3.7 Segregation of SG iron The non-uniform distribution of solute elements during solidification results in the micro segregation of SG iron.As for the redistribution of elements in the phases of the solidification structure,there is no intrinsic difference between SG iron and grey iron[132].

  6. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Spheroidal Graphite Cast Iron(Ⅲ) 3.6 Solidification morphology of SG iron Solidification morphology refers to the description of change,distribution and interrelationship of the solidification structures such as graphite spheroids,austenite,eutectic cells,etc.[99

  7. Cast iron - a predictable material

    Directory of Open Access Journals (Sweden)

    Jorg C. Sturm

    2011-02-01

    Full Text Available High strength compacted graphite iron (CGI or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven

  8. Control of Cast Iron Microstructure

    Science.gov (United States)

    Graham, J.; Lillybeck, N.; Franco, N.; Stefanescu, D. M.

    1985-01-01

    The use of microgravity for industrial research in the processing of cast iron was investigated. Solidification experiments were conducted using the KC-135 and F-104 aircraft, and an experiment plan was developed for follow-on experiments using the Shuttle. Three areas of interest are identified: (1) measurement of thermophysical properties in the melt; (2) understanding of the relative roles of homogeneous nucleation, grain multiplication, and innocultants in forming the microstructure; and (3) exploring the possibility of obtaining an aligned graphite structure in hypereutectic Fe, Ni, and Co.

  9. Cementite Solidification in Cast Iron

    Science.gov (United States)

    Coronado, J. J.; Sinatora, A.; Albertin, E.

    2014-06-01

    Two hypereutectic cast irons (5.01 pct Cr and 5.19 pct V) were cast and the polished surfaces of test pieces were deep-etched and analyzed via scanning electron microscopy. The results show that graphite lamellae intersect the cementite and a thin austenite film nucleates and grows on the cementite plates. For both compositions, graphite and cementite can coexist as equilibrium phases, with the former always nucleating and growing first. The eutectic carbides grow from the austenite dendrites in a direction perpendicular to the primary plates.

  10. Chilling Tendency and Chill of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    E. Fra(s); M. Górny; W. Kapturkiewicz; H. López

    2008-01-01

    An analytical expression is presented for the susceptibility of liquid cast iron to solidify according tothe Fe-C-X metastable system (also known as the chilling tendency of cast iron, CT). The analysis incorpo-rates the nucleation and growth processes associated with the eutectic transformation. The CT is related tothe physicochemical state of the liquid, the eutectic cells in the flake graphite, and the number of nodules innodular cast iron. In particular, the CT can be related to the critical wall thickness, Scr, or the chill width, Wcr,in wedge shaped castings. Finally, this work serves as a guide for understanding the effect of technical fac-tors such as the melt chemistry, the spheroidizing and inoculation practice, and the holding time and tam-perature on the resultant CT and chill of the cast iron. Theoretical calculations of Scr and Wcr compare wellwith experimental data for flake graphite and nodular cast iron.

  11. Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅰ

    Directory of Open Access Journals (Sweden)

    Zhou Jiyang

    2010-02-01

    Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

  12. Dynamic fracture behavior of nodular cast iron

    International Nuclear Information System (INIS)

    Ferritic nodular cast iron has been found to be a much tougher material than previously believed based on Charpy impact test results. As a result this material is being considered as a substitute for Stainless Steel in nuclear waste transport containers. We have determined Klc and Kld values for nodular cast iron with varying values of silicon and percentage of pearlite in the matrix. Regular V-notch charpy bars and fatigue precracked charpy bars have been tested to determine the initiation and propagation energy and the effect of notch acuity on transition temperature. (author)

  13. 49 CFR 192.287 - Plastic pipe: Inspection of joints.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe: Inspection of joints. 192.287... Than by Welding § 192.287 Plastic pipe: Inspection of joints. No person may carry out the inspection of joints in plastic pipes required by §§ 192.273(c) and 192.285(b) unless that person has been qualified...

  14. 46 CFR 153.239 - Use of cast iron.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet...

  15. Research on Welding Test of Grey Cast Iron and Low-Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Grey cast iron's welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However the carbon component in low-carbon steel is comparatively low,the carbo n of welded joint will diffuse to the low-carbon steel when it is welded with gr ey cast iron,which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ,high carbon martensite and cracks ...

  16. Inoculation of chromium white cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-01-01

    Full Text Available It has been proved that an addition of boron carbide introduced as an inoculant to the chromium white cast iron changes the structureof castings. Castings after inoculation revealed a different structure with numerous grains. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

  17. Thin Wall Cast Iron: Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Doru M. Stefanescu

    2005-07-21

    The development of thin-wall technology allows the designers of energy consuming equipment to select the most appropriate material based on cost/material properties considerations, and not solely on density. The technology developed in this research project will permit the designers working for the automotive industry to make a better informed choice between competing materials and thin wall cast iron, thus decreasing the overall cost of the automobile.

  18. Eutectic solidification mode of spheroidal graphite cast iron and graphitization

    OpenAIRE

    Hideo Nakae; Sanghoon Jung; Takayuki Kitazawa

    2007-01-01

    The shrinkage and chilling tendency of spheroidal graphite (abbreviated SG) cast iron is much greater than that of the flake graphite cast iron in spite of its higher amount of C and Si contents. Why? The main reason should be the difference in their graphitization during the eutectic solidification. In this paper, we discuss the difference in the solidification mechanism of both cast irons for solving these problems using unidirectional solidification and the cooling curves of the spheroidal...

  19. Eutectic solidification mode of spheroidal graphite cast iron and graphitization

    Directory of Open Access Journals (Sweden)

    Hideo Nakae

    2007-02-01

    Full Text Available The shrinkage and chilling tendency of spheroidal graphite (abbreviated SG cast iron is much greater than that of the flake graphite cast iron in spite of its higher amount of C and Si contents. Why? The main reason should be the difference in their graphitization during the eutectic solidification. In this paper, we discuss the difference in the solidification mechanism of both cast irons for solving these problems using unidirectional solidification and the cooling curves of the spheroidal graphite cast iron. The eutectic solidification rate of the SG cast iron is controlled by the diffusion of carbon through the austenite shell, and the final thickness is 1.4 times the radius of the SG, therefore, the reduction of the SG size, namely, the increase in the number, is the main solution of these problems.

  20. Interaction between alloying and hardening of cast iron surface

    Institute of Scientific and Technical Information of China (English)

    刘政军; 郝雪枫; 傅迎庆; 牟力军

    2002-01-01

    To improve wear resistance of surface will increase the service life of gray cast iron directly. This paper presents that gray cast iron surface coated with alloy powder is locally remelted by TIG arc to increase the wear resistance. The influences of arc current and scanning rate etc on surface properties are found. Under different conditions, the microstructure, hardness and wear resistance of remelted layer are analyzed and measured. The results indicate that the gray cast iron surface can be strengthened by TIG arc local remelting treatment. Especially, surface alloying hardening effect is best and surface properties are improved remarkably.

  1. Engineering development of expansion joint at nuclear reactor piping system

    International Nuclear Information System (INIS)

    It has been done an analysis and modeling of power reactor piping system. The purpose of this activity is to determine whether the stress that occurred in the piping system under stress conditions which allowed or not. To cope with stress arising from expansion of pipe, one of ways, is to install the expansion joint due to the limited dimensions of the space. The method used is to retrieve reference data generated from software CAESAR II and catalog expansion joint then can be calculated to determine the specifications of an expansion joint that will be installed. From the analysis and the calculation are known that there is excessive stress on piping systems and can be overcome by the installation of the expansion joint that can easily be found in the domestic market. (author)

  2. Eutectic solidification mode of spheroidal graphite cast iron and graphitization

    Institute of Scientific and Technical Information of China (English)

    Hideo Nakae; Sanghoon Jung; Takayuki Kitazawa

    2007-01-01

    The shrinkage and chilling tendency of spheroidal graphite (abbreviated SG) east iron is much greater than that of the flake graphite cast iron in spite of its higher amount of C and Si contents. Why? The main reason should be the difference in their graphitization during the eutectic solidification. In this paper, we discuss the difference in the solidification mechanism of both cast irons for solving these problems using unidirectional solidification and the cooling curves of the spheroidal graphite cast iron. The eutectic solidification rate of the SG cast iron is controlled by the diffusion of carbon through the austenite shell, and the final thickness is 1.4 times the radius of the SG, therefore, the reduction of the SG size, namely, the increase in the number, is the main solution of these problems.

  3. INCREASE OF EFFICIENCY OF MODIFIERS FOR GRAY CAST-IRON

    Directory of Open Access Journals (Sweden)

    O. S. Komarov

    2012-01-01

    Full Text Available It is established that for the purpose of increase of modifying efficiency of the melt from gray cast iron it is possible to use mechanically alloyed aluminum powder with superdispersed particles of aluminum and graphite oxide.

  4. WEAR-RESISTANCE OF CHROMIC CAST IRONS OF EUTECTIC COMPOSITION

    Directory of Open Access Journals (Sweden)

    K. E. Baranovskij

    2009-01-01

    Full Text Available Casting of wear-resistant chrome cast irons in combined molds and iron chills is studied. Application of these ways of casting results in blending of carbides and increasing of hardness of castings.

  5. Inoculated Slightly Hypereutectic Gray Cast Irons

    Science.gov (United States)

    Chisamera, Mihai; Riposan, Iulian; Stan, Stelian; Militaru, Cristina; Anton, Irina; Barstow, Michael

    2012-03-01

    The current experimental investigation in this article was designed to characterize the structure of mold (M) and ladle (L) inoculated, low-S (0.025 wt.% S), low-Al (0.003 wt.% Al), slightly hypereutectic (CE = 4.4-4.5 wt.%) electric melted gray irons, typical for high performance thin-wall castings. It describes the effect of a Ca, Al, Zr-FeSi inoculant addition of 0-0.25 wt.% on structure characteristics, and compares to similar treatments with hypoeutectic irons (3.5-3.6 wt.% CE, 0.025 wt.% S, and 0.003 wt.% Al). A complex structure including primary graphite, austenite dendrites, and eutectic cells is obtained in hypereutectic irons, as the result of nonequilibrium solidification following the concept of a coexisting region. Dendrites appear to be distributed between eutectic cells at higher eutectic undercooling, while in inoculated irons and for lower undercooling, the eutectic cells are "reinforced" by eutectic austenite dendrites. A Zr, Ca, Al-FeSi alloy appears to be an effective inoculant in low S, low Al, gray cast irons, especially for a late inoculation technique, with beneficial effects on both graphite and austenite phases. First, inoculation influenced the nucleation of graphite/eutectic cell, and then their characteristics. A further role of these active elements directly contributed to form nucleation sites for austenite, as complex (Mn,X)S particles.

  6. Fracture analysis of chilled cast iron camshaft

    Institute of Scientific and Technical Information of China (English)

    Li Ping; Li Fengjun; Cai Anke; Wei Bokang

    2009-01-01

    The fracture of a camshaft made of chilled cast iron, installed in a home-made Fukang car, happened only after running over a distance of 6,200 km. The fractured camshaft was received to conduct a series of failure analyses using visual inspection, SEM observation of fracture section, microstructure analysis, chemical composition analysis and hardness examination and so on, while those of CKD camshaft made by Citroen Company in France was also simultaneously analyzed to compare the difference between them. The results showed that the fracture of the camshaft mainly results from white section in macrostructure and Ledeburite in microstructure; the crack in the fractured camshaft should be recognized to initiate at the boundary of coarser needle-like carbide and matrix, and then propagate through the transverse section. At the same time, the casting defects such as dendritic shrinkage, accumulated inclusion and initiated crack and abnormal external force might stimulate the fracture of camshaft as well. Based on failure analysis, some measures have been employed, and as a result, the fracture of home-made camshafts has been effectively prevented.

  7. Solidification of cast iron - A study on the effect of microalloy elements on cast iron

    DEFF Research Database (Denmark)

    Moumeni, Elham

    in the fraction of primary austenite and formation of superfine interdendritic graphite have been investigated using Thermocalc simulations and metallographic studies. TiC did not appear to be a nucleation site for the primary austenite as it was found mostly at the periphery of the secondary arms......The present thesis deals with the heat transfer and solidification of ductile and microalloyed grey cast iron. Heterogeneous nucleation of nodular graphite at inclusions in ductile iron during eutectic solidification has been investigated. A series of ductile iron samples with two different...... the unetched, colour-etched and deep-etched samples. It was confirmed that in irons with high sulphur content (0.12 wt%) nucleation of type-A and type-D graphite occurs on Mn sulphides that have a core of complex Al, Ca, Mg oxide. An increased titanium level of 0.35% produced superfine interdendritic graphite...

  8. Properties shaping and repair of selected types of cast iron

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2007-04-01

    Full Text Available The paper presents research results of twofold use of TIG - Tungsten Inert Gas also known as GTA - Gas Tungsten Arc. First is surfacing by welding on cold and hot-cold to repair chromium cast iron with chromium content about 15%. Second is remelting with electric arc of selected gray (with pearlitic matrix and ductile (with ferritic-pearlitic matrix cast iron. Repair of cast iron elements was realized in order to cut out a casting defects. Defects decrease a usability of castings for constructional application and increase a manufacturing costs. Application of surface heat treatment guarantees mechanical properties i.e. hardness and wear resistance improvement. The result of investigations show possibility of castings repair by put on defects a good quality padding welds, which have comparable properties with base material. Use of electric arc surface heat treatment resulted in increase of hardness and wear resistance, which was measured on the basis of ASTM G 65 - 00 standard.

  9. Residual stresses in a cast iron automotive brake disc rotor

    Energy Technology Data Exchange (ETDEWEB)

    Ripley, Maurice I. [Australian Nuclear Scinece and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)]. E-mail: m.ripley@ansto.gov.au; Kirstein, Oliver [Australian Nuclear Scinece and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)

    2006-11-15

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed.

  10. Residual stresses in a cast iron automotive brake disc rotor

    International Nuclear Information System (INIS)

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed

  11. Control of microstructure of cast irons Indefinite Chill Double Pour-ICDP

    Directory of Open Access Journals (Sweden)

    T.Válek

    2011-10-01

    Full Text Available ICDP cast irons designated for working layer of centrifugal cylinders of rolling mill must have precisely defined properties. The most closely observed parameters of the ICDP (Indefinite Child Double Pour cast irons are the following: the amount of graphite in a microstructure and hardness of base metal material. Secretion of graphite in cast iron with ledeburitic basic metal compound is a complex process that can be controlled and managed with the use of thermal analysis. On the basis of the evaluation of cooling curve parameters of cast iron there is performed metallurgical adjustment of meltage by adding elements supporting graphite end carbide formation into cast iron. The identified structural and mechanical properties of ICDP cast irons were correlated with recorded KO. Subsequently, a methodology for control of the metallurgical adjustment of cast iron before casting was proposed so as to ensure the desired microstructure and properties the ICDP cast iron.

  12. The influence of cooling rate on the hardness of cast iron with nodular and vermicular graphite

    OpenAIRE

    M.S. Soiński; B. Zatoń; A. Skoczylas; A. Derda

    2008-01-01

    The paper presents hardness changes for cast iron with nodular and vermicular graphite, determined within the separately cast test blocks. Investigation has comprised cast irons with similar ferrite and pearlite fractions in the metal matrix. The hardness measurements have been performed by Brinell method for samples taken both from an edge and from the centre of a Y block (for nodular cast iron) or of a reversed U block (in the case of vermicular cast iron). Investigations have pertained bot...

  13. 49 CFR 192.285 - Plastic pipe: Qualifying persons to make joints.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe: Qualifying persons to make joints... Materials Other Than by Welding § 192.285 Plastic pipe: Qualifying persons to make joints. (a) No person may make a plastic pipe joint unless that person has been qualified under the applicable joining...

  14. Torch Brazing Methods for Cast Iron QT500-7 and Its Influence on Performance of Brazed Joints%QT500—7铸铁火焰钎焊方法及其对接头性能的影响

    Institute of Scientific and Technical Information of China (English)

    王振波; 陈春焕

    2012-01-01

    Using B-Ag40CuZnCdNi alloy as filler metal, cast iron QT500 7 was connected by torch brazing. The effect of filler metal placement method and heating time on the shear strength of the brazed joints was studied by shear test and microstructure observation. The results showed that when sandwich method was used to place the filler metal, the joint was likely to cause welding defects, and the carrying capacity of the joint was lower than that of base metal. When capillary method was used in enough heating time, the filling process of the liquid metal had also played a role of cleaning the gap of brazing seam, which was helpful to get the joint with thin and straight brazing seam and less defects, so the shear strength had been improved, when the heating time was more than 5 min, the carrying capacity of the joint was higher than that of base metal, but it will be not as good as sandwich method if the heating time was insufficient.%以B-Ag40CuZnCdNi合金为钎料,采用火焰钎焊方法实现了QT500—7铸铁的连接。研究了“三明治”法和毛细法两种钎料放置方式及不同加热时间对钎焊接头抗剪强度的影响,并对连接界面的微观组织进行了分析。结果表明:用“三明治”法放置钎料时,接头容易产生焊接缺陷,接头的承载能力低于母材;用毛细法放置钎料时,在足够长的加热时间条件下,液态钎料的填缝过程同时具有清洁钎缝间隙的作用,有利于得到钎缝细小平直且缺陷少的接头,因此抗剪强度得到提高,加热时间大于5min时,接头承载能力高于母材,但加热时间不足时反而不如“三明治”法的施焊效果。

  15. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  16. Solidification and microstructure of thin walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin

    2006-01-01

    In the recent years there has been an increasing interest in light constructions in order to save weight in e.g. cars. Ductile cast iron has good mechanical properties but it is necessary to re­duce the wall thicknesses of the castings in order to reduce the weight. Reducing the wall thicknesses ...

  17. Colour Metallography of Cast Iron Chapter 2 Introduction (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2009-01-01

    @@ Grey iron is type of cast iron with grey color fracture and carbon precipitated as flake graphite.According to its chemical compostion in Fe-C phase diagram,grey iron is categorised into three types:hypoeutectic,eutecitic,hypereutecitic irons are hypoeutecic compostion.

  18. Effect of the Carbides and Matrix on the Wear Resistance of Nodular Cast Iron

    Directory of Open Access Journals (Sweden)

    G. Gumienny

    2013-07-01

    Full Text Available This paper presents the results of the abrasive wear resistance of selected types of nodular cast iron, including ADI, cooperating with quartz sand and 100 grit abrasive paper. It has been shown that carbides in nodular cast iron cause an increase in wear resistance of 6 to 12% depending on the surface fraction of the carbides and type of the matrix. For the same unit pressure the mass loss of the cast iron cooperating with quartz sand is many times larger than the cast iron cooperating with abrasive paper. For both abrasives the highest wear resistance showed nodular cast iron with upper and lower bainite and carbides.

  19. Product and process innovation of grey cast iron brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Schorn, M. [Brembo S.P.A. (Italy)

    2006-07-01

    The brake disc out of grey cast iron often seems to be playing the role of the ''underdog'' in the technical examinations of the entire brake system. This is also reflected by the 25 year history of the {mu}-club. In a total of 93 presentations in those 25 years, only 3 were related to the topic of grey cast iron discs. This is not a correct relation to the importance of this component within the brake system. The disc, although per definition with a lower specific load than the pad, has the major task to store and dissipate the heat in which the kinetic energy of the vehicle is transformed. The disc also has a significant effect on NVH behaviour, particularly in the low frequency range. It also has a permanent fight with its weight as an unsprung mass. (orig.)

  20. SURFACE CAST IRON STRENGTHENING USING COMBINED LASER AND ULTRASONIC PROCESSING

    Directory of Open Access Journals (Sweden)

    O. Devojno

    2013-01-01

    Full Text Available The paper provides an analysis of ultrasonic surface plastic deformation and subsequent laser thermal strengthening of gray cast iron parts in the regime of hardening from a solid state with the purpose to obtain strengthened surface layers of bigger depth and less roughness of the processed surface. Program complex ANSYS 11.0 has been used for calculation of temperature fields induced by laser exposure.  The appropriate regime of laser processing without surface fusion has been selected on the basis of the applied complex. The possibility of displacement in the bottom boundary of α–γ-transformation temperature  for СЧ20 with 900 °С up to 800 °С is confirmed due to preliminary ultrasonic surface plastic deformation of the surface that allows to expand technological opportunities of laser quenching  of gray  cast iron from a solid state. 

  1. Role of yttrium in heavy section spheroidal graphite cast iron

    International Nuclear Information System (INIS)

    Magnesium ferrosilicon alloys (Mg = 5-7%) are widely used abroad, while rare earth-magnesium ferrosilicon alloys (Mg = 8-10%, Ce RE = 5-9%) are used predominantly in China. Recently, due to the exploitation of natural resources of yttrium rare earth at home, a new type of alloy--yttrium based-rare earth ferrosilicon (YRE=25-40%, Si=40%) has been developed and put into trail as a substitute for conventional rare earth magnesium ferrosilicon alloy in some of the foundries for manufacturing heavy section spheroidal graphite cast iron. In this paper the effect of yttrium on mechanical properties and microstructures of heavy section spheroidal graphite cast iron are studied. Some simulating experiments were carried out in laboratory

  2. Fracture toughness behaviour of ferritic ductile cast iron

    International Nuclear Information System (INIS)

    The static rate fracture toughness of a series of eight heats of ductile cast iron has been measured. Samples from each heat were tested in a heat treated condition which produced a fully ferritic matrix. The chemical composition and the microstructural feature size has also been measured directly from each specimen tested. A multiple linear regression method was used to establish a simple mathematical relationship between fracture toughness and the composition and microstructure. Fracture toughness was found to be strongly associated with the spacing (or size) of the graphite nodules in these fully ferritic ductile cast irons. Other features, including the composition, the ferrite grain size, or the amount of graphite (over the ranges examined), did not strongly influence the fracture toughness. Fracture toughness also did not correlate with tensile properties (i.e. strength or ductility) in these alloys. (author)

  3. Stereology of carbide phase in modified hypereutectic chromium cast iron

    Directory of Open Access Journals (Sweden)

    J. Suchoń

    2010-04-01

    Full Text Available In paper are presented results of studies of carbide phase stereology modified hypereutectic wear resistance chromium cast iron which contains carbon about 3,5% and chromium about 25%. Three substances were applied to the modification: boron carbide (B4C, ferroniobium (FeNb and mixture of ferroniobium and rare-earth (RE. The measurements of geometrical features of carbides were conducted on microsection taken from castings wich were cooled with various velocities.

  4. Stereology of carbide phase in modified hypereutectic chromium cast iron

    OpenAIRE

    J. Suchoń; A. Studnicki; M. Przybył

    2010-01-01

    In paper are presented results of studies of carbide phase stereology modified hypereutectic wear resistance chromium cast iron which contains carbon about 3,5% and chromium about 25%. Three substances were applied to the modification: boron carbide (B4C), ferroniobium (FeNb) and mixture of ferroniobium and rare-earth (RE). The measurements of geometrical features of carbides were conducted on microsection taken from castings wich were cooled with various velocities.

  5. Niobium alloying effect in high carbon equivalent grey cast iron

    OpenAIRE

    Zhou Wenbin; Zhu Hongbo; Zheng Dengke

    2011-01-01

    The effect of niobium on the formation of NbC phase and solidification structure in high carbon equivalent grey cast iron was investigated. The experimental results indicated that an increase in the niobium content is favorable to refining the graphite and eutectic cell; and the pearlite lamellar spacing is reduced. Based on the thermodynamic calculation the formation of NbC is prior to the eutectic reaction. The reduction in the pearlite lamellar spacing is mainly attributed to the decrease ...

  6. Tribological Aspects of Cast Iron Investigated Via Fracture Toughness

    OpenAIRE

    C. Fragassa; Minak, G; A. Pavlovic

    2016-01-01

    Linear-elastic plane-strain fracture toughness of metallic materials is a method which covers the determination of the strain fracture toughness (KIC) of metallic materials by increasing-force test of fatigue precracked specimens. This method has been applied for investigating the fracture behaviour of cast iron. Two groups of cast alloys, Compacted Graphite Iron (CGI) and Spheroidal Graphite Iron (SGI) have been investigated. While SGI benefits of a wide scientific literature, CGI is a relat...

  7. Conventional flow curves of liquid cast iron put on spheroidization

    Directory of Open Access Journals (Sweden)

    B. Borowiecki

    2008-04-01

    Full Text Available The purpose of the investigation was to confirm the hypothesis that the conventional flow curves of liquid cast iron put on sferoidization determined from the rod fluidity test are comparable to flow curves of liquids in environmental temperature. Moreover has been identified, that conventional flow curves for this liquid cast iron are similar to generalized non- Newtonian liquids curves.For rods with the diameters 3-8 mm there are three various curves:1 – the flow curve of liquid cast iron put on spheroidization overheated about 80 K resemble a shape adequately to a curve of densified liquid with shearing. This phenomenon can be caused by high overcooled and creation of crystallization nuclei;2 – metal alloys overheated about 180 K resemble a shape adequately to Newtonian liquid;3 – metal alloys overheated about 210 K resemble a shape of curve adequately to dispersed liquid with shearing. This phenomenon probably depends on influence of gas which creates on boundary of metal-sand mould.

  8. Model-Based Detection of Pipe Leakage at Joints

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taejin; Youn, Byeng D.; Woo, Sihyong [Seoul National University, Seoul (Korea, Republic of)

    2015-03-15

    Time domain reflectometry (TDR) is widely used for wire failure detection. It transmits a pulse that is reflected at the boundaries of different characteristic impedances. By analyzing the reflected signal, TDR makes it possible to locate the failure. In this study, TDR was used to detect the water leakage at a pipe joint. A wire attached to the pipe surface was soaked by water when a leak occurred, which affected the characteristic impedance of the wet part, resulting in a change in the reflected signal. To infer the leakage from the TDR signal, we first developed a finite difference time domain-based forward model that provided the output of the TDR signal given the configuration of the transmission line. Then, by solving the inverse problem, the locations of the leaks were found.

  9. Investigation of Residual Stresses and Distortion in Welded Pipe-Flange Joint of Different Classes

    OpenAIRE

    Muhammad Abid

    2012-01-01

    ABSTRACT: Pipe and flange joints are commonly used in petrochemical, nuclear and process industries. Commonly, welding is used to make these joints which produces residual stresses and distortions. These stresses have detrimental effects on the structural integrity and service performance of the welded pipe joints. The objective of this study is to investigate the residual stresses and distortions during Gas Metal Arc Welding of pipe of schedule 40, nominal diameter 200 mm with different ANSI...

  10. High Temperature Corrosion of Fe-C-S Cast Irons in Oxidizing and Sulfidizing Atmospheres

    Institute of Scientific and Technical Information of China (English)

    Thuan-Dinh NGUYEN; Dong-Bok LEE

    2008-01-01

    The corrosion behavior of spheroidal graphite and flake graphite cast irons was studied in oxidizing and sulfidizing atmospheres between 600 and 800℃ for 50 h. The corrosion rate in the sulfidizing atmosphere was faster than that in air above 700℃, due to the formation of the Feo.975S sulfide. The corrosion rate of the spheroidal graphite cast iron was similar to that of the flake graphite cast iron.

  11. The effect of microstructure of low-alloy spheroidal cast iron on impact strength

    Directory of Open Access Journals (Sweden)

    T. Szykowny

    2010-01-01

    Full Text Available The study presents an evaluation of the effect of microstructure of low-alloy spheroidal cast iron on impact strength within the temperature range from –60 to 100°C. Analyses were conducted on one type of cast iron containing 0.51% Cu and 0.72% Ni. Cast iron was austempered or normalized. Values of KCV and static mechanical properties were determined. Structural and fractographic analyses were based on light and scanning microscopy as well as X-ray diffraction. It was found that thermal processing considerably improves impact strength in relation to cast iron after casting. At the same time static mechanical properties are enhanced.

  12. Effect of Heat Treatment on Mechanical Property of High Cr-W Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Liu Jianping; Li Lixia

    2007-01-01

    The microstructure of high Cr-W cast iron after heat treatment were analyzed, and the effect of various heat treatment temperature and time on mechanical properties of high Cr-W cast iron were studied, and the best process parameter of heat treatment was provided in this paper. The results show that the heat treatment can improve the mechanical property of high Cr-W cast iron, and higher synthetic mechanical property of high Cr-W cast iron can be obtained when treated with normalization at 980℃ for 2h and tempered at 400℃ for 2h.

  13. The influence of cooling rate on the hardness of cast iron with nodular and vermicular graphite

    Directory of Open Access Journals (Sweden)

    M. S. Soiński

    2008-12-01

    Full Text Available The paper presents hardness changes for cast iron with nodular and vermicular graphite, determined within the separately cast test blocks. Investigation has comprised cast irons with similar ferrite and pearlite fractions in the metal matrix. The hardness measurements have been performed by Brinell method for samples taken both from an edge and from the centre of a Y block (for nodular cast iron or of a reversed U block (in the case of vermicular cast iron. Investigations have pertained both to the test parts and to the sinkheads of the test blocks. Hardness measurements have been completed with metallographic examination.

  14. Fracture mechanics behaviour of ductile cast iron and martensitic steel at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Udoh, A.; Klenk, A.; Roos, E. [Stuttgart Univ. (Germany). MPA; Sasikala, G. [Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam (India)

    2010-07-01

    Ductile cast iron is employed increasingly due to the advantages regarding foundry practice, design as well as economic advantages in the thermal machinery and power plant construction. It is employed preferably where higher toughness is required, e.g. in valves or thickwalled components of thermal or nuclear power plants. For this reason the safety and availability criteria for fracture mechanics assessment of components are necessary in addition to the conventional strength design. Alloys with silicon and molybdenum are developed for the application at higher temperatures. The increase in the thermal efficiency of fossil fired steam power plant that can be achieved by increasing the steam temperature and pressure has provided the incentive for development of the 9% chromium steels towards improved creep rupture strength. During the last twenty years, three such steels, P91 (9Cr-1Mo-VNb), E911 (9Cr-1Mo-1W-V-Nb) and P92 (9Cr-0,5Mo-1,8W-V-Nb), have been developed for commercial production. For application in piping systems and boiler construction sufficient reliable information concerning the long-term behaviour are necessary as well as knowledge about fracture mechanical behaviour in order to ensure integrity of components. Different methods to characterize fracture behaviour of ductile cast iron and martensitic steel at elevated temperature have been employed. The RBR method is a novel and simple method developed at IGCAR for characterizing the ductile fracture behaviour of materials from tensile tests of cylindrical specimens. Using the data evaluated at both institutes, a fracture mechanics characterisation by determining crack initiation and crack resistance by J{sub R}-curves and RBR parameters is presented. (orig.)

  15. Primary and secondary crystallization of modified hypoeutectic chromium cast iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2010-04-01

    Full Text Available The paper presents investigations of crystallization of modified hypoeutectic wear resistant chromium cast iron which contains carbon about 2% and chromium on three levels (12%, 18% and 25%. Three substances were applied to the modification ( boron carbide (B4C, ferroniobium (FeNb and mixture of ferroniobium and mischmetal (RE. The investigations of crystallization were conducted the DTA method in DTA-C and DTA-Is testers. The influence on the course of the process of primary and secondary crystallization was observed.

  16. Carbides in Nodular Cast Iron with Cr and Mo

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2007-07-01

    Full Text Available In these paper results of elements microsegregation in carbidic nodular cast iron have been presented. A cooling rate in the centre of the cross-section and on the surface of casting and change of moulding sand temperature during casting crystallization and its self-cooling have been investigated. TDA curves have been registered. The linear distribution of elements concentration in an eutectic grain, primary and secondary carbides have been made. It was found, that there are two kinds of carbides: Cr and Mo enriched. A probable composition of primary and secondary carbides have been presented.

  17. Microstructure and properties of cast iron after laser surface hardening

    Directory of Open Access Journals (Sweden)

    Stanislav

    2013-12-01

    Full Text Available Laser surface hardening of cast iron is not trivial due to the material’s heterogeneity and coarse-grained microstructure, particularly in massive castings. Despite that, hardening of heavy moulds for automotive industry is in high demand. The present paper summarises the findings collected over several years of study of materials structure and surface properties. Phase transformations in the vicinity of graphite are described using examples from production of body parts in automotive industry. The description relates to formation of martensite and carbide-based phases, which leads to hardness values above 65 HRC and to excellent abrasion resistance.

  18. Solidification, processing and properties of ductile cast iron

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat

    2010-01-01

    Ductile cast iron has been an important engineering material in the past 50 years. In that time, it has evolved from a complicated material that required the foundry metallurgist's highest skill and strict process control to being a commonly used material that can easily be produced with modern...... process technology. Yet, for the skilled metallurgist and foundry engineer, it is a material that can be engineered to meet extreme demands with regard to mechanical properties and geometrical complexity. It is therefore a material that has been in growing use since its discovery. And the results...

  19. Recent development of ductile cast iron production technology in China

    Institute of Scientific and Technical Information of China (English)

    Cai Qizhou; Wei Bokang

    2008-01-01

    Recent progress in the production and technology of ductile cast iron castings in China is reviewed.The manufacture and process control of as-cast ductile iron are discussed.The microstructure.properties and application of partial austenitization normalizing ductile iron and austempered duclile iron(ADI)are briefly depicted.The new development of duclile iron production techniques,such as cored-wire injection(wire-feeding nodularization)process,tundish cover ladle nodularizing process,horizontal continuous casting,and EPC process (lost foam)for ductile iron castings,etc.,are summarized.

  20. Tribological Aspects of Cast Iron Investigated Via Fracture Toughness

    Directory of Open Access Journals (Sweden)

    C. Fragassa

    2016-03-01

    Full Text Available Linear-elastic plane-strain fracture toughness of metallic materials is a method which covers the determination of the strain fracture toughness (KIC of metallic materials by increasing-force test of fatigue precracked specimens. This method has been applied for investigating the fracture behaviour of cast iron. Two groups of cast alloys, Compacted Graphite Iron (CGI and Spheroidal Graphite Iron (SGI have been investigated. While SGI benefits of a wide scientific literature, CGI is a relatively unknown material despite of its large potentialities in industrial applications.

  1. Model of Primary Austenite Dendrite Structure in Hypoeutectic Cast Iron

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The solidification of primary austenite in hypoeutectic gray cast iron was studied by stepped grinding and quantitative metallography. The dendrite structure of primary austenite can be described by three models: typical dendrite crystal model, metamorphic dendrite crystal model and network dendrite crystal model. The dendrite crystals formed according to 3rd model is much more than those formed according to other models in this experiment. The primary austenites are connected each other, and the primary stems of austenite could be regarded as secondary arms and vice versa.

  2. Age Strengthening of Gray Cast Iron Phase III

    Energy Technology Data Exchange (ETDEWEB)

    Von L. Richards; Wayne Nicola

    2003-06-26

    The primary objective of this research is to identify the age strengthening mechanism in gray and ductile cast iron, and to quantify the parameters that control it. It is also to contribute to a new predictive model for gray and ductile iron strength and hardness. This work shows that age strengthening occurs on a sigmoidal-logarithmic scale in gray and ductile cast irons, to a statistically significant extent. This is similar to Avrami-Johnson-Mehl kinetics for phase transformations in metals. It occurs in both cupola-melted iron and induction melted iron. However, it does not happen in all compositions. We have developed some understanding of the process. Data suggests that nitrogen and nitride-forming trace elements have a significant role in the process, but that is yet not fully characterized. Also, the time dependence of the bulk hardness and strength increase, the nano-scale precipitation evidence from neutron scattering, differential scanning calorimetry results and matrix micro-hardness increase in ferrite all indicate that age strengthening occurs by a precipitation or pre-precipitate cluster formation mechanism.

  3. Fatigue properties of ductile cast iron containing chunky graphite

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, P., E-mail: ferro@gest.unipd.it [Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, I-36100 Vicenza (Italy); Lazzarin, P.; Berto, F. [Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, I-36100 Vicenza (Italy)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer Experimental determination of high cycle fatigue properties of EN-GJS-400. Black-Right-Pointing-Pointer Evaluation of the influence of chunky graphite morphology on fatigue life. Black-Right-Pointing-Pointer Metallurgical analysis and microstructural parameters determination. Black-Right-Pointing-Pointer Nodule counting and nodularity rating. - Abstract: This work deals with experimental determination of high cycle fatigue properties of EN-GJS-400 ductile cast iron containing chunky graphite. Constant amplitude axial tests were performed at room temperature under a nominal load ratio R = 0. In order to evaluate the influence of chunky graphite morphology on fatigue life, fatigue tests were carried out also on a second set of specimens without this microstructural defect. All samples were taken from the core of a large casting component. Metallurgical analyses were performed on all the samples and some important microstructural parameters (nodule count and nodularity rating, among others) were measured and compared. It was found that a mean content of 40% of chunky graphite in the microstructure (with respect to total graphite content) does not influence significantly the fatigue strength properties of the analysed cast iron. Such result was attributed to the presence of microporosity detected on the surface fracture of the specimens by means of electron scanning microscope.

  4. Multiphysics and multiscale modelling of ductile cast iron solidification

    Directory of Open Access Journals (Sweden)

    D. Gurgul

    2010-01-01

    Full Text Available The presented model of ductile cast iron solidification is a typical sample of multiphysics and multiscale engineering system. This model takes into consideration the different time and spatial scales of accounted phenomenon of microstructure formation: heat diffusion, components mass diffusion in the liquid and solid phases, thermodynamic of phase transformation under the condition of inhomogeneous chemical composition of growing and vanishing phases, phase interface kinetics and grains nucleation.The results of two-dimensional modelling of the microstructure formation in the ductile cast iron (so called - Ductile Iron - DI are pre-sented. The cellular automaton model (CA was used for the simulation. Six states of CA cells were adopted to three phases above men-tioned (liquid, austenite and graphite and to three two-phase interfaces. For the modelling of concentration and temperature fields the numerical solution was used. The parabolic nonlinear differential equa-tions with a source term were solved by using the finite difference method and explicit scheme. The overlapping lattices with the same spatial step were used for the concentration field modelling and for the CA. The time scale of the temperature field for this lattice is about 104 times shorter. Due to above reasons the another lattice was used with a multiple spatial step and the same time step.

  5. Displaying structural property and inheritance of cast iron surfacing on steel base

    Science.gov (United States)

    Shveev, I. A.

    2016-06-01

    Graphite inclusions heredity in deposited layer from remelted special cast iron billets was established. The possibility of controlling the structural state and the quality of the deposited layer due to technological parameters of welding and heat treatment of parts is shown. Ways of improving cast iron wear resistance durability are proposed.

  6. Influences on Burr Size During Face-Milling of Aluminum Alloys and Cast Iron

    OpenAIRE

    Shefelbine, Wendy; Dornfeld, David

    2004-01-01

    The Exit Order Sequence (EOS) theory discussed by previous LMA students predicts the size of burrs formed during face milling. Other influences are tool geometry, coolant use, and material properties in aluminum silicon alloys and cast iron. Used, worn tools also increase the size of the burr. The effect of speed and feed are also discussed, particularly with regards to cast iron.

  7. The temperature gradient on section of casting in process of primary crystallization of chromium cast iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2008-08-01

    Full Text Available The methodology of defining in article was introduced the temperature gradient in process of primary crystallization during cooling the casting from chromium cast iron on basis of measurements of thermal field in test DTA-K3. Insert also the preliminary results of investigations of influence temperature gradient on structure of studied wear resistance chromium cast iron.

  8. CASTING OF DETAILS OF WEAR-RESISTANT CHROME CAST IRONS FOR CHROMIC MILLS IN COMBINED MOLDS AND CHILLS

    Directory of Open Access Journals (Sweden)

    K. E. Baranovskij

    2009-01-01

    Full Text Available Relative wear resistance of chrome cast irons of eutectic composition is determined in laboratory and industry conditions. Complex alloyed eutectic cast iron with increased wear resistance and mechanical characteristics is developed.

  9. Effect of Chemical Composition on Number of Eutectic Colonies in Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2013-01-01

    Full Text Available Determined were direction and intensity of influence of alloying additions on the number of eutectic graphite colonies in austenitic cast iron Ni-Mn-Cu. Chemical composition of the cast iron was 1.7 to 3.3% C, 1.4 to 3.1% Si, 2.8 to 9.9% Ni, 0.4 to 7.7% Mn, 0 to 4.6% Cu,0.14 to 0.16% P and 0.03 to 0.04% S. Analysed were structures of mottled (20 castings and grey (20 castings cast iron. Obtained wereregression equations determining influence intensity of individual components on the number of graphite colonies per 1 cm2 (LK. It wasfound that, in spite of high total content of alloying elements in the examined cast iron, the element that mainly decides the LK value is carbon, like in a plain cast iron.

  10. Seismic fragility of threaded Tee-joint connections in piping systems

    International Nuclear Information System (INIS)

    This paper proposes a methodology to evaluate seismic fragility of threaded Tee-joint connections found in typical hospital piping systems. Existing experimental data on threaded Tee-joints of various sizes subjected to monotonic and cyclic loading indicates that the “First Leak” damage state is observed predominantly due to excessive flexural deformations at the Tee-joint section. The results of the monotonic and cyclic loading tests help us evaluate the characteristics for a given pipe size and material. A non-linear finite element model for the Tee-joint system is formulated and validated with the experimental results. It is shown that the Tee-joint section can be satisfactorily modeled using non-linear rotational springs. The system-level fragility of the complete piping system corresponding to the “First Leak” damage state is determined from multiple time-history analyses using a Monte-Carlo simulation accounting for uncertainties in demand. - Highlights: • Seismic Fragility of piping systems. • Reconciliation of experimental and analytical results in piping systems. • Monotonic and cyclic behavior threaded piping joints. • First-leakage limit-states in threaded piping joints. • System level reliability of fire sprinkler piping systems

  11. THE RESULTS OF MAGNETIC CONTROL OF STRUCTURE OF THE WHITE CAST IRON INGOTS BEFORE ANNEALING FOR MALLEABLE

    Directory of Open Access Journals (Sweden)

    S. G. Sandomirskij

    2009-01-01

    Full Text Available Investigations of dependence of remanent flux in small-sized castings of white cast iron on content of areas with structure of grey cast iron are given. Solution of problem of non- allowance on extraction of castings with structure of grey cast iron is offered. Recommendations on using of control means are given.

  12. Identification Trial of Crystallization Parameters of Modified Chromium Cast Iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2007-07-01

    Full Text Available In the paper results of researches of abrasion-resisting chromium cast iron inoculated with boron carbide B4C primary crystallization are presented. The main aim of work was make an attempt to identification of crystallization parameters that changed in reason of inoculation. Essential primary crystallization parameters, with the help of which, will be possible to evaluate the inoculation capacity were searched. It was found that in the result of inoculant actions characteristic temperatures were changed and time of primary crystallization was decreased. For tests the new broadened Derivative Thermal Analysis method, in which three samples with different solidification module were applied, was used. Thanks to this inoculation capacity in casts with significant diversified self-cooling ranges was possible to observe.

  13. Thermodynamic stability of austenitic Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2014-07-01

    Full Text Available The performed research was aimed at determining thermodynamic stability of structures of Ni-Mn-Cu cast iron castings. Examined were 35 alloys. The castings were tempered at 900 °C for 2 hours. Two cooling speeds were used: furnace-cooling and water-cooling. In the alloys with the nickel equivalent value less than 20,0 %, partial transition of austenite to martensite took place. The austenite decomposition ratio and the related growth of hardness was higher for smaller nickel equivalent value and was clearly larger in annealed castings than in hardened ones. Obtaining thermodynamically stable structure of castings requires larger than 20,0 % value of the nickel equivalent.

  14. As-Cast Acicular Ductile Aluminum Cast Iron

    Institute of Scientific and Technical Information of China (English)

    S M Mostafavi Kashani; S M A Boutorabi

    2009-01-01

    The effects of nickel (2.2%)and molybdenum (0.6%)additions on the kinetics, microstructure, and me-chanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic structure, resulting in an increase in strength and hardness. The same trend was shown when the test bars were tempered at 300 ℃ in the range of 300℃ to 400 ℃. The elongation increased with increasing the temperature from 300 ℃ to 400 ℃. The carbon content of the retained austenite also increased with increasing the temperature. The results also showed that the kinetics, mi-crostructure, and mechanical properties of this iron were similar to those of Ni-Mo alloyed silicon ductile iron.

  15. Mechanism of silicon influence on the chill of cast iron

    Directory of Open Access Journals (Sweden)

    E. Fraś

    2007-12-01

    Full Text Available In this work an analytical solution of general validity is used to explain mechanism of the silicon influence on the absolute chill tendency (CT and chill (w of cast iron. It is found that CT can be related to nucleation potential of graphite (Nv, growth parameter (μ of eutectic cells, temperature range (ΔTsc and the pre-eutectic austenite volume fraction (fγ. It has been shown that silicon additions: a impede the growth of graphite eutectic cells, μ, b expands the temperature range ΔTsc, c increases the nucleation potential of graphite Nv, d lowers the pre-eutectic austenite volume fraction, fγ. and in consequence the absolute chilling tendency, CT decreases. The minimum wall thicknesses for chilled castings, or chill widths (w in wedge shaped castings is related to CT and as silcon contents increases, the w value also increases.

  16. Quality improvement through microstructure control for superior machinability of cast irons

    Science.gov (United States)

    Marwanga, Reuben Omwega

    The purpose of this research was to study the influence of microstructure on chip formation and other machinability criteria for cast irons. It is recognized that machinability of cast irons is influenced by a complex interplay of graphite morphology and matrix structure. However, the effect of these microstructural variables on the measures of machinability of cast irons has not been adequately investigated. As a consequence the problem of variability in the machinability of this group of materials is not well understood. In this study, slow speed machining and the quick-stop device method were used to investigate the mechanism by which graphite morphology and the matrix structure influence the machining properties of cast irons. Furthermore, turning tests were used to study machinability as characterized by tool life, machining forces and surface roughness for these materials. Relationships between chip formation and other machinability criteria were then developed and analyzed. Finally, empirical models that relate machinability to microstructures for cast irons were developed. The study showed that chip formation and other machinability parameters for cast irons were influenced by both graphite morphology and matrix structure. In addition, the empirical models revealed that machinability of cast irons was not only influenced by microstructural variables but also by the interaction of the variables with cutting conditions.

  17. CHANGE OF CONNECTION BETWEEN MAGNETIC PARAMETERS OF CAST IRON IN COMPARISON WITH STEEL UNDER INFLUENCE OF INTERNAL DEMAGNETIZATION

    Directory of Open Access Journals (Sweden)

    S. G. Sandomirsky

    2014-01-01

    Full Text Available Connection of maximum magnetic permeability µm of cast irons with coercive force Нс and residual magnetism Мr is established in all size of changing of the magnetic characteristics of cast iron. Differences of this connection for steels and cast irons are revealed. Formula for calculation µm of steels by Нс and Мr is corrected for calculation µm of cast irons. As a result of correction the calculation error of cast irons µm is diminished. The results can be used in magnetic structural analysis instead of labor-consuming measurement µm.

  18. Comparative aspects about the studying methods of cast irons machinability, based on the tool wear

    Science.gov (United States)

    Carausu, C.; Pruteanu, O.

    2016-08-01

    The paper presents some considerations of the authors, regarding the studying methods of the cast irons machinability, based on the tools wear on drilling operations. Are described the conditions in which the experimental researches were conducted, intended to offer an overview on drilling machinability of some cast irons categories. It is presented a comparison between long-term methods and short-term methods, for determining the optimal speed chipping of a grey cast iron with lamellar graphite, with average values of tensile strength. Are described: the research methodology, obtained results and conclusions drawn after the results analysis.

  19. Dissimilar joining of nickel aluminide intermetallic compound with spheroidal graphite cast iron by using combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kimata, T.; Uenishi, K.; Kobayashi, K.F. [Dept. of Manufacture Science, Osaka Univ., Osaka (Japan); Ikenaga, A. [Dept. of Metallurgy and Material Science, Osaka Prefecture Univ., Osaka (Japan)

    2004-07-01

    Nickel aluminide based intermetallic compounds were combustion synthesized from a powder mixture of elemental Al, Ni, and Si and were simultaneously bonded with spheroidal graphite cast iron substrate (FCD). Addition of Si to the elemental mixture of Al and Ni was confirmed to be effective both to the densification of combustion synthesized intermetallic compounds and to the joining between compounds and FCD. When the composition of precursor was Ni-69at%Al-9at%Si (Al/Si is the ratio of the eutectic composition), Al{sub 3}Ni and Al{sub 6}Ni{sub 3}Si were mainly combustion synthesized. In the interface between compounds and FCD, reaction layers were formed to the thickness of 10 {mu}m and the constitutent phases were identified as Al{sub 7}Fe{sub 2}Si, FeAl{sub 3} respectively. In the four point bending test of the dissimilar joints prepared by heating at 973 K for 300 s, the brittle fracture did not occurred around the joint interface but mainly in the inside of nickel aluminide coating. The interface of reaction layers with 10 {mu}m were chemically well bonded. The sample with Ni-69at%Al-9at%Si coating exhibited highest bonding strength of about 56 MPa because of the smallest void ratio of the obtained compounds. (orig.)

  20. Anodic Dissolution of Spheroidal Graphite Cast Iron with Different Pearlite Areas in Sulfuric Acid Solutions

    Directory of Open Access Journals (Sweden)

    Yoshikazu Miyata

    2013-01-01

    Full Text Available The rate equation of anodic dissolution reaction of spheroidal graphite cast iron in sulfuric acid solutions at 298 K has been studied. The cast irons have different areas of pearlite. The anodic Tafel slope of 0.043 V decade−1 and the reaction order with respect to the hydroxyl ion activity of 1 are obtained by the linear potential sweep technique. The anodic current density does not depend on the area of pearlite. There is no difference in the anodic dissolution reaction mechanisms between pure iron and spheroidal graphite cast iron. The anodic current density of the cast iron is higher than that of the pure iron.

  1. APPLICATION OF ALLOYED-DIFFUSED CARBONACEOUS WIRE FOR MODIFYING OF CAST IRON

    Directory of Open Access Journals (Sweden)

    V. M. Konstantinov

    2010-01-01

    Full Text Available The process of modifying of cast iron by diffusingalloyed steel wire is studied. The peculiarities of structure formation of diffused layer at thermal-cyclic treatment of wire are established.

  2. Testing of heating and cooling process of ADI cast iron with use of ATND method

    Directory of Open Access Journals (Sweden)

    A. Białobrzeski

    2008-10-01

    Full Text Available ADI (Austempered Ductile Iron cast iron, owing to its unique combination of high tensile strength and abrasion resistance with very goodplasticity, founds implementation in many branches of industry as a substitute of alloy cast steel and carburized or heat treated steels. Inspite of its solid position among producers and recipients of castings, there are still undertaken studies aimed at perfection of its propertiesand recognition of mechanisms enabling obtaining such properties.The paper presents implementation of thermal-voltage-derivative (ATND method to registration of heating and cooling course of ADIcast iron with EN-GJS-1200-2 grade. ADI cast iron with EN-GJS-1200-2 grade underwent the study. Heat treatment of the cast iron wasperformed in Foundry Institute with use of LT ADI-350/1000 processing line. Results obtained from the testing illustrate in graphic formregistered heating and cooling curves of investigated cast irons obtained with use of the ATND method.

  3. INVESTIGATION OF PHYSICOCHEMICAL AND MECHANICAL CHARACTERISTICS OF STEEL AND CAST IRON CHIPS

    Directory of Open Access Journals (Sweden)

    O. M. Dyakonov

    2009-01-01

    Full Text Available The chemical and phase composition of steel and cast iron chips is studied, quantitative content of phases, including ferric oxides and other chemical elements chips, is determined.

  4. Examination of Cast Iron Material Properties by Means of the Nanoindentation Method

    Directory of Open Access Journals (Sweden)

    A. Trytek

    2012-12-01

    Full Text Available The paper presents results of examination of material parameters of cast iron with structure obtained under rapid resolidification conditions carried out by means of the nanoindentation method.

  5. TDA method application to austenite transformation in nodular cast iron with carbides assessment

    Directory of Open Access Journals (Sweden)

    G. Gumienny

    2011-07-01

    Full Text Available In this paper the possibility of TDA method using to austenite transformation in nodular cast iron with carbides assessment is presented. Studies were conducted on cast iron with about 2% molybdenum and 0,70% to 4,50% nickel. On diagrams, where TDA curves are pre- sented, on time axis a logarithmic scale was applied. It has not been used up to now. It was found, that during cooling and crystallization of cast iron in TDA probe, on the derivative curve there is a slight thermal effect from austenite to upper bainite or martensite transformation. Depending on nickel concentration austeniteupper bainite transformation start temperature changed (Bus, while MS temperature was independent of it. An influence of nickel on eutectic transformation temperature in nodular cast iron with carbides was determined too.

  6. On the weldability of grey cast iron using nickel based filler metal

    International Nuclear Information System (INIS)

    Shielded metal arc welding process using nickel based filler metal was used to join grey cast iron. The effect of post weld heat treatment (PWHT) on the microstructure and hardness was studied. PWHT included heating up to 870 oC, holding for 1 h at 870 oC and then furnace cooling. By using nickel based filler metal, formation of hard brittle phase (e.g. carbides and martensite) in the fusion zone is prevented. Before PWHT, heat affected zone exhibited martensitic structure and partially melted zone exhibited white cast iron structure plus martensite. Applied PWHT resulted in the dissolution of martensite in heat affected zone and graphitization and in turn the reduction of partially melted zone hardness. Results showed that welding of grey cast iron with nickel based filler metal and applying PWHT can serve as a solution for cast iron welding problems.

  7. RESEARCH AND APPLICATION OF AS-CAST WEAR RESISTANCE HIGH CHROMIUM CAST IRON

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The influence of alloy elements, such as boron and silicon, on the microstructure and properties of as-cast high chromium cast iron is studied. The results show that boron and silicon have a great effect on the mechanical properties and the wear resistance. Through proper addition of boron and silicon, the properties of as-cast high chromium cast iron can be improved effectively. Through analyzing the distribution of elements by scanning electron microscope, it has been shown that the addition of boron and silicon lowers the mass fraction of chromium saturated in as-cast austenite, and makes it unstable and liable to be transformed into martensite. The as-cast high chromium cast iron with proper content of boron and silicon is suitable for the manufacture of lining for asphalt concrete mixer and its wear resistance is 14 times that of lining made of low alloy white cast iron.

  8. Cast iron with spherical graphite is a perspective material for NPP equipment manufacture

    International Nuclear Information System (INIS)

    High-plasticity austenitic and ferritic spheroidal graphite cast irons are designed. The ferritic spheroidal graphite cast iron is shown to have a high fracture toughness after additional recrystallization heat treatment. The nodular cast iron is noted to show promise for components operating under irradiation. Domestic experience of production of ferritic and austenitic nodular cast irons of high fracture toughness permits to cast any complex-shaped components. This fact in combination with good workability gives the possibility of decreasing the number of labour consuming operations in manufacturing as spent fuel storage and shipping casks so other components of NPPs. The nodular irons are recommended to be used instead of steel 00Kh13NDP and 0Kh18N9T forgings

  9. Influence of selected modifiers on crystallization curve of chromium cast iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2009-07-01

    Full Text Available In article was introduced the results of investigations of modified chromium cast iron crystallization process. It the cast iron about composition of basic elements C = 2,8 % and Cr = 18% was modified with five substances (boron carbide, ferrosilicon, ferrocalciumsilicon, ferroniobium and ferroniobium with ferrovanadium. Influence on course of primary and secondary crystallization process was observed. The investigations of crystallization was conducted DTA method in tester DTA - C.

  10. A new type of antifriction and wear resistant malleable cast iron

    Science.gov (United States)

    Davidov, S. V.; Gorlenko, A. O.

    2016-04-01

    There is developed a technology of malleable cast iron modification on the basis of complex chemical compound of surface-active elements and their solid solutions with other elements. Silicon high content in malleable cast iron helped to develop a power efficient technology of graphitizing annealing which has considerably lower annealing temperature and complete renunciation of the second graphitizing annealing stage at the expense of its change by controlled cooling up to ferrite structure or by air cooling for perlite structure.

  11. Ductile cast iron obtaining by Inmold method with use of LOST FOAM process

    Directory of Open Access Journals (Sweden)

    T. Pacyniak

    2010-01-01

    Full Text Available The possibility of manufacturing of ductile cast iron castings by Inmold method with use of LOST FOAM process was presented in this work. The spheroidization was carried out by magnesium master alloy in amounts of 1% casting mass. Nodulizer was located in the reactive chamber in the gating system made of foamed polystyrene. Pretests showed, that there are technical possibilities of manufacturing of casts from ductile cast iron in the LOST FOAM process with use of spheroidization in mould.

  12. Influence of spheroidal cast iron wall thickness on its microstructure and ultrasonic control index

    OpenAIRE

    W. Orłowicz; M. Tupaj; M. Mróz; E. Guzik; E. Gierut; W. Pilut; A. Zimowski

    2009-01-01

    This work presents results of ultrasonic evaluation of the microstructure of spheroidal cast iron manufactured under production conditions.Evaluation of the ultrasonic control index’s sensitiveness to changes in microstructure (graphite shape index Ss and average number of graphite precipitations NA) of cast iron, was made on modelled stepped castings. A relation between the graphite precipitation shape index Ss and the velocity of longitudinal ultrasonic wave cL has been defined, as well as ...

  13. Graphite Nodule and Cell Count in Cast Iron

    Directory of Open Access Journals (Sweden)

    E Fraś

    2007-07-01

    Full Text Available In this work, a model is proposed for heterogeneous nucleation on substrates whose size distribution can be described by the Weibull statistics. It is found that the nuclei density, Nnuc can be given in terms of the maximum undercooling, ΔTm by Nnuc = Ns exp(-b/ΔTm; where Ns is the density of nucleation sites in the melt and b is the nucleation coefficient (b > 0 . When nucleation occurs on all the possible substrates, the graphite nodule density, NV,n or eutectic cell density NV after solidification equals Ns. In this work, measurements of NV,n and NV values were carried out on experimental nodular and flake graphite iron castings processed under various inoculation conditions. The volumetric nodule NV,,n or graphite eutectic cell NV count, were estimated from the area nodule count, NA,n or eutectic cell count NA on polished cast iron surface sections by stereological means. In addition, maximum undercoolings, ΔTm were measured using thermal analysis. The experimental outcome indicates that volumetric nodule NV,n or graphite eutectic cell NV count can be properly described by the proposed expression NV,,n = NV = Ns exp(-b/ΔTm. Moreover, the Ns and b values were experimentally determined. In particular, the proposed model suggests that the size distribution of nucleation sites is exponential in nature.

  14. Heat Treatment in High Chromium White Cast Iron Ti Alloy

    Directory of Open Access Journals (Sweden)

    Khaled M. Ibrahim

    2014-01-01

    Full Text Available The influence of heat treatment on microstructure and mechanical properties of high chromium white cast iron alloyed with titanium was investigated. The austenitizing temperatures of 980°C and 1150°C for 1 hour each followed by tempering at 260°C for 2 hours have been performed and the effect of these treatments on wear resistance/impact toughness combination is reported. The microstructure of irons austenitized at 1150°C showed a fine precipitate of secondary carbides (M6C23 in a matrix of eutectic austenite and eutectic carbides (M7C3. At 980°C, the structure consisted of spheroidal martensite matrix, small amounts of fine secondary carbides, and eutectic carbides. Titanium carbides (TiC particles with cuboidal morphology were uniformly distributed in both matrices. Irons austenitized at 980°C showed relatively higher tensile strength compared to those austenitized at 1150°C, while the latter showed higher impact toughness. For both cases, optimum tensile strength was reported for the irons alloyed with 1.31% Ti, whereas maximum impact toughness was obtained for the irons without Ti-addition. Higher wear resistance was obtained for the samples austenitized at 980°C compared to the irons treated at 1150°C. For both treatments, optimum wear resistance was obtained with 1.3% Ti.

  15. Cast iron deterioration with time in various aqueous salt solutions

    Indian Academy of Sciences (India)

    Rita Mehra; Aditi Soni

    2002-02-01

    The changes with time in the corrosion rate and corrosion current density on a cast iron electrode in various aqueous salt solutions have been carried out using total immersion test and potentiostatic polarization curves. The concentration of salts taken is expected to be present in potable water. The relative behaviour of these salts towards corrosion has also been studied, which is found to be different from previous studies. The total immersion test parameters viz. weight loss, corrosion rate as well as potentiostatic parameters, open circuit potential, corr, Tafel slopes, corrosion rate, have been calculated by standard methods. Besides these the relative increase in corrosion rate with time as well as the percentage to which corrosion rate should be decreased so as to provide protection towards corrosion have also been calculated. It was found that KCl and NaCl are major contributors than MnSO4, Pb(NO3)2, KI and KBr. The relative increase in corrosion is high in KBr, KI, NaNO3, CaCl2, and less in Pb(NO3)2, NaHCO3 and CaCO3 test solutions. For the reliability of results the data has been statistically analysed.

  16. Obtaining Martensitic Structures during Thixoforming of Hypoeutectic Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    Lucas Bertolino Ragazzo

    2015-01-01

    Full Text Available The control of parameters such as liquid fraction, holding time, and cooling rate during thixoforming can help control the final microstructure of the thixoformed part, thus improving its mechanical properties. This study intended to investigate conditions required to obtain martensite in hypoeutectic gray cast iron at 3.1% CE (carbon equivalent deformed in the semisolid state. Samples heated up to 1130, 1135, and 1145°C (liquid fractions of 10, 30, and 45% were compressed into platens without any holding time (0 s. If a sample presented a martensitic structure for 0 s holding time, new samples were retested at the same temperature for 30, 60, and 90 s holding times. The die casting process was simulated by allowing the platens to become locked after hot compression. Samples that cooled in the locked platens were submitted to higher cooling rates than samples that cooled with the platens open and presented martensite instead of the conventional ferrite and pearlite. Thus, the factor that had the greatest influence on the formation of martensite was the cooling rate rather than stress. The thixoforming process presented good morphological stability, which is highly desirable for industrial applications.

  17. Superfluid helium testing of a stainless steel to titanium piping transition joint

    Energy Technology Data Exchange (ETDEWEB)

    Soyars, W.; /Fermilab; Basti, A.; Bedeschi, F.; /INFN, Pisa; Budagov, J.; /Dubna, JINR; Foley, M.; Harms, E.; Klebaner, A.; Nagaitsev, S.; /Fermilab; Sabirov, B.; Dubna, JINR

    2009-11-01

    Stainless steel-to-titanium bimetallic transitions have been fabricated with an explosively bonded joint. This novel joining technique was conducted by the Russian Federal Nuclear Center, working under contract for the Joint Institute for Nuclear Research. These bimetallic transitions are being considered for use in future superconducting radio-frequency cavity cryomodule assemblies. This application requires cryogenic testing to demonstrate that this transition joint remains leak-tight when sealing superfluid helium. To simulate a titanium cavity vessel connection to a stainless steel service pipe, bimetallic transition joints were paired together to fabricate piping assemblies. These piping assemblies were then tested in superfluid helium conditions at Fermi National Accelerator Laboratory test facilities. The transition joint test program will be described. Fabrication experience and test results will be presented.

  18. Inverse Kinematics Analysis of Weld Inspection Manipulator at Pipe Joint in Nuclear Industry

    Institute of Scientific and Technical Information of China (English)

    鄢波; 颜国正; 刘华

    2004-01-01

    A redundant manipulator that can online clamp pipe was developed to track along a cylinder intersection curve. With an ultrasonic transducer mounted on its end-effector, the manipulator can perform welding seam inspection at pipe joint in nuclear industry. An inverse kinematics solution expressed in joint space was solved based on the combination of geometric method and D-H matrix transformation. Expression about joints variables was obtained based on the scanning parameters of pipeline. The analysis method and results can be widely applied for online trajectory planning of intersection curve scanning manipulators.

  19. Strain analysis on ductile cast iron containers at drop tests

    International Nuclear Information System (INIS)

    Ductile cast iron (DCI) containers for transportation and deposition of radioactive waste have to be designed carefully in order to avoid unacceptable damages and leakages in case of an accident. Therefore various calculations and experimental methods are used during development and licensing of the containers. Besides others the container has to suffer severe impacts (e.g. falling from a height of several meters onto a concrete base). The level of strains must not exceed a value which would adversely affect the package in such a way that it would fail to meet the applicable requirements. In practice complex events such as drop tests are very difficult to calculate. Both the position of maximum stress and the time of its occurrence are not easily predicted with the method of FEM. The uncertainty of the material modelling for plastic deformation by dynamic loading rates is the limiting factor. Therefore holography as an integral measuring technique in combination with strain gauge techniques were used to fit the FEM. By using the FEM calculations in the case of licensing, the FE and the material model have to be verified. The verification of the FEmodel has to be done by comparison of the local maxima measured by strain gauges and by comparison of the vibration modes. These vibration modes we take from holographic measurements. In this paper we explain container vibrations after impact analysed with holographic measurements, FEM calculations and the comparison of the results. The comparison of the local maxima (strain gauges/FEM) is reported elsewhere (Schreiber 1993; Voelzer 1997). (orig.)

  20. A repair process for an heterogenous welded joint between a nuclear reactor component tube and a pipe

    International Nuclear Information System (INIS)

    The repairing process involves cutting a tubular section of the tube and the pipe, which includes the welded joint, and preparing an austenitic stainless steel tubular section for substitution; the section is then narrow-joint welded with the low-alloy steel tube, and finally welded to the austenitic stainless steel pipe. Application to repairing a welded joint between a PWR pressurizer tube and the expansion pipe of the pressurizer. (authors). 7 refs., 3 figs

  1. Ultrasonic inspection of nodular cast iron insert edge distance using curved linear PA-probe

    Energy Technology Data Exchange (ETDEWEB)

    Lipponen, A.; Sarkimo, M. (VTT Technical Research Centre of Finland, Espoo (Finland)); Pitkaenen, J. (Posiva Oy, Eurajoki (Finland))

    2010-05-15

    Nuclear fuel disposal canisters consist of a copper tube and a cast iron insert. The copper tube is designed for corrosion protection. The design and use of the nodular cast iron insert is based on strength and fracture mechanic aspects and it is the load carrying part of the structure. The preliminary acceptance criteria for the cast iron insert are under study. There are several aspects in accepting the inspection results of nodular cast iron insert for use. One aspect among others is the position of the edge which is nearest to surface. In an earlier study this was stated to have a tolerance of edge position +- 5 mm. There have been studies both on eccentricity and the real position of the nearest edge tolerances. To determine the edge position, different ultrasonic techniques were tested using a curved linear PA-probe. To evaluate whether the distance variation is within the tolerance limit, the real geometrical nominal distance must be computed. Because the tolerances of the cast iron insert and its internal geometry can give a large variation in the edge position, these must be carefully evaluated. The applied ultrasonic system is a 128 element phased array equipment. The used probe is curved and adjusted to curvature of the cast iron insert. The curved probe was designed to inspect the edge of the channel with one long axial line scanning. During line scanning the phased array probe does at the same time electronical scanning. To optimize this electronic scanning, three different ultrasonic techniques were used. This evaluation of edge distance was tested in four inspections of real size cast iron inserts. It was seen that the variation of the edge position is about 1 to 12 mm in radial direction (straightness) and in circumferential direction about 2 to 8 mm (twist) in range of about 4 m. (orig.)

  2. An innovative method for nondestructive analysis of cast iron artifacts at Hopewell Furnace National Historic Site, Pennsylvania

    Science.gov (United States)

    Sloto, Ronald A.; Martin f. Helmke,

    2014-01-01

    For this study, we sampled iron ore, cast iron furnace products, slag, soil, groundwater, streamflow, and streambed sediment. It was important for us to determine which trace metals from the smelted ore were incorporated into the cast iron in order to provide a complete picture of the fate of those metals. It was the only missing piece of information after all other media were sampled. Standard techniques were used to sample and analyze all media except cast iron. Standard techniques require collecting samples in the field, shipping them to a laboratory, and performing a destructive analysis. We needed a nonstandard approach for analysis of the cast iron artifacts.

  3. Vacuum Bellows, Vacuum Piping, Cryogenic Break, and Copper Joint Failure Rate Estimates for ITER Design Use

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Cadwallader

    2010-06-01

    The ITER international project design teams are working to produce an engineering design in preparation for construction of the International Thermonuclear Experimental Reactor (ITER) tokamak. During the course of this work, questions have arisen in regard to safety barriers and equipment reliability as important facets of system design. The vacuum system designers have asked several questions about the reliability of vacuum bellows and vacuum piping. The vessel design team has asked about the reliability of electrical breaks and copper-copper joints used in cryogenic piping. Research into operating experiences of similar equipment has been performed to determine representative failure rates for these components. The following chapters give the research results and the findings for vacuum system bellows, power plant stainless steel piping (amended to represent vacuum system piping), cryogenic system electrical insulating breaks, and copper joints.

  4. The sort of carburization and the quality of obtained cast iron

    Directory of Open Access Journals (Sweden)

    K. Janerka

    2008-12-01

    Full Text Available In the production of cast iron, the pig iron’s amount in charge material is more and more often limited, and replaced by steel scrap. That extorts the necessity of know-how the carburization and one is looking for carburizers, which ensure obtaining big carbon increment as quickly as possible with the high repeatability and the ones which ensure getting the adequate quality of cast iron. The object of presented research was definition of the influence of charge materials’ sort on the structure, course of solidification, and the effectiveness of process. The cast iron melts, which are presented below, are made only on the basis of steel scrap with portion of graphitoidal, coke and anthracite carburizers, which were added to the charge in solid. In the article one compared the carburizers in respect of their structure, chemical constitution and the effectiveness obtained during the carburization of liquid metal. The melting of cast iron, based on the special pig iron, was carried out as well. The course of melts, chemical constitution of obtained cast iron and its structure were presented. The comparison between quality distribution and the volume fraction of graphite in classes of size for the individual melts were achieved and the TDA curves were inserted.

  5. In-situ surface hardening of cast iron by surface layer metallurgy

    International Nuclear Information System (INIS)

    Abrasive wear is a serious problem in many cast iron castings used in industry. To minimize failure and repair of these components, different strategies exist to improve their surface microhardness thus enhancing their wear resistance. However, most of these methods lead to very brittle and/or expensive castings. In the current work a new method for surface hardening is presented which utilizes surface layer metallurgy to generate in-situ a boron-enriched white cast iron surface layer with a high microhardness on a gray cast iron casting. To do this, sand molds are coated with a ferroboron suspension and cast with a cast iron melt. After solidification, a 100–900 µm thick layer of boron-enriched ledeburite is formed on the surface of the casting which produces an increase in the average microhardness from 284 HV0.1±52 HV0.1 to 505 HV0.1±87 HV0.1. Analyses of the samples' core reveal a typical cast iron microstructure which leads to the conclusion that the coating mainly affects the castings' surface. By varying the grain size of the ferroboron powder in the coatings, it is shown that a powder size ≤100 µm is most suitable to create a boron-enriched ledeburite surface layer possessing high hardness values

  6. In-situ surface hardening of cast iron by surface layer metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Sebastian F., E-mail: s.fischer@gi.rwth-aachen.de [Foundry Institute, RWTH Aachen University, Intzestraße 5, 52072 Aachen (Germany); Muschna, Stefan, E-mail: smuschna@yahoo.de [Foundry Institute, RWTH Aachen University, Intzestraße 5, 52072 Aachen (Germany); Bührig-Polaczek, Andreas, E-mail: sekretariat@gi.rwth-aachen.de [Foundry Institute, RWTH Aachen University, Intzestraße 5, 52072 Aachen (Germany); Bünck, Matthias, E-mail: m.buenck@access-techcenter.de [Access e.V., Intzestraße 5, 52072 Aachen (Germany)

    2014-10-06

    Abrasive wear is a serious problem in many cast iron castings used in industry. To minimize failure and repair of these components, different strategies exist to improve their surface microhardness thus enhancing their wear resistance. However, most of these methods lead to very brittle and/or expensive castings. In the current work a new method for surface hardening is presented which utilizes surface layer metallurgy to generate in-situ a boron-enriched white cast iron surface layer with a high microhardness on a gray cast iron casting. To do this, sand molds are coated with a ferroboron suspension and cast with a cast iron melt. After solidification, a 100–900 µm thick layer of boron-enriched ledeburite is formed on the surface of the casting which produces an increase in the average microhardness from 284 HV{sub 0.1}±52 HV{sub 0.1} to 505 HV{sub 0.1}±87 HV{sub 0.1}. Analyses of the samples' core reveal a typical cast iron microstructure which leads to the conclusion that the coating mainly affects the castings' surface. By varying the grain size of the ferroboron powder in the coatings, it is shown that a powder size ≤100 µm is most suitable to create a boron-enriched ledeburite surface layer possessing high hardness values.

  7. TO SELECTION OF TECHNOLOGICAL SCHEME OF SOFTENING HEAT TREATMENT FOR HIGH CHROMIUM CAST IRON

    Directory of Open Access Journals (Sweden)

    V. G. Efremenko

    2014-03-01

    Full Text Available Purpose. High chromium cast irons with austenitic matrix have low machinability. The aim of work is search of new energy-saving modes of preliminary softening heat treatment enhancing the machinability of castings by forming an optimum microstructure. Methodology. Metallographic analysis, hardness testing and machinability testing are applied. Findings. It was found out that high temperature annealing with continuous cooling yields to martensite-austenite matrix in cast iron 270Х15Г2Н1MPhT, which abruptly affects the machinability of cast iron. Significant improvement of machinability is achieved by forming of structure "ferrite + granular carbides" and by decline of hardness to 37-39 HRC in the case of two-stage isothermal annealing in the subcritical temperature range or by the use of quenching and tempering (two-step or cyclic. Originality. It was found that the formation of the optimal structure of the matrix and achievement of desired hardness level needed for improving machinability of high chromium cast iron containing 3 % austenite-forming elements, can be obtained: 1 due to pearlite original austenite followed by spherodization eutectoid carbides, and 2 by getting predominantly martensite structure followed by the decay of martensite and carbides coagulation at high-temperature tempering. Practical value. The new energy-saving schemes of softening heat treatment to ensure the growth of machinability of high chromium cast iron, alloyed by higher quantity of austenite forming elements, are proposed.

  8. Monitoring of Quality of Vermicular Cast Iron from the Front of the Furnace

    Institute of Scientific and Technical Information of China (English)

    LI Dayong; SHI Dequan; WANG Lihua

    2008-01-01

    Verrnicular cast iron is used in certain fields because of its special physical properties. However, it is difficult to control the quality from the front of the furnace owing to the narrow range of vermiculizer and other elements that can be added to the iron. A real time method was developed to monitor the vermioular-graphite ratio of the cast iron based on fast measurements of the melt surface tension. The system includes a detector and a control unit that measure the amplitude and frequency of bubbles rising in the melt. This paper describes the methodology for measuring the surface tension of the melt and test results monitoring the vermicular-graphite ratio of the vermicular cast iron from the front of the furnace. The relationship be-tween surface tension and graphite shape has been established. The results show that this system can quickly evaluate the verrnicular-graphite ratio of the cast iron.Key words: vermicular cast iron; surface tension; graphite shape

  9. Evaluation of residual stress distribution in austenitic stainless steel pipe butt-welded joint

    International Nuclear Information System (INIS)

    This paper reports measured and estimated results of residual stress distributions of butt-welded austenitic stainless steel pipe in order to improve estimation accuracy of welding residual stress. Neutron diffraction and strain gauge method were employed for the measurement of the welding residual stress and its detailed distributions on inner and outer surface of the pipe as well as the distributions within the pipe wall were obtained. Finite element method was employed for the estimation. Transient and residual stresses in 3D butt-welded joint model were computed by employing Iterative Substructure Method and also commercial FEM code ABAQUS for a reference. The measured and estimated distributions presented typical characteristic of straight butt-welded pipe which had decreasing trend along the axial direction and bending type distributions through wall of the pipe. Both results were compared and the accuracy of measurement and estimation was discussed. (author)

  10. New developments in high quality grey cast irons

    Directory of Open Access Journals (Sweden)

    Iulian Riposan

    2014-07-01

    Full Text Available The paper reviews original data obtained by the present authors, revealed in recent separate publications, describing specific procedures for high quality grey irons, and reflecting the forecast needs of the worldwide iron foundry industry. High power, medium frequency coreless induction furnaces are commonly used in electric melting grey iron foundries. This has resulted in low sulphur (1,500 °C, contributing to unfavourable conditions for graphite nucleation. Thin wall castings are increasingly produced by these electric melt shops with a risk of greater eutectic undercooling during solidification. The paper focused on two groups of grey cast irons and their specific problems: carbides and graphite morphology control in lower carbon equivalent high strength irons (CE=3.4%-3.8%, and austenite dendrite promotion in eutectic and slightly hypereutectic irons (CE=4.1%-4.5%, in order to increase their strength characteristics. There are 3 stages and 3 steps involving graphite formation, iron chemistry and iron processing that appear to be important. The concept in the present paper sustains a threestage model for nucleating flake graphite [(Mn,XS type nuclei]. There are three important groups of elements (deoxidizer, Mn/S, and inoculant and three technological stages in electric melting of iron (superheat, pre-conditioning of base iron, final inoculation. Attention is drawn to a control factor (%Mn x (%S ensuring it equals to 0.03 – 0.06, accompanied by 0.005wt.%–0.010wt.% Al and/or Zr content in inoculated irons. It was found that iron powder addition promotes austenite dendrite formation in eutectic and slightly eutectic, acting as reinforcement for the eutectic cells. But, there is an accompanying possible negative influence on the characteristics of the (Mn,XS type graphite nuclei (change the morphology of nuclei from polygonal compact to irregular polygonal, and therefore promote chill tendency in treated irons. A double addition (iron

  11. New developments in high quality grey cast irons

    Institute of Scientific and Technical Information of China (English)

    Iulian Riposan; Mihai Chisamera; Stelian Stan

    2014-01-01

    The paper reviews original data obtained by the present authors, revealed in recent separate publications, describing speciifc procedures for high quality grey irons, and relfecting the forecast needs of the worldwide iron foundry industry. High power, medium frequency coreless induction furnaces are commonly used in electric melting grey iron foundries. This has resulted in low sulphur (1,500 °C), contributing to unfavourable conditions for graphite nucleation. Thin wall castings are increasingly produced by these electric melt shops with a risk of greater eutectic undercooling during solidiifcation. The paper focused on two groups of grey cast irons and their speciifc problems: carbides and graphite morphology control in lower carbon equivalent high strength irons (CE=3.4%-3.8%), and austenite dendrite promotion in eutectic and slightly hypereutectic irons (CE=4.1%-4.5%), in order to increase their strength characteristics. There are 3 stages and 3 steps involving graphite formation, iron chemistry and iron processing that appear to be important. The concept in the present paper sustains a three-stage model for nucleating flake graphite [(Mn,X)S type nuclei]. There are three important groups of elements (deoxidizer,Mn/S, and inoculant) and three technological stages in electric melting of iron (superheat, pre-conditioning of base iron, ifnal inoculation). Attention is drawn to a control factor (%Mn) x (%S) ensuring it equals to 0.03- 0.06, accompanied by 0.005wt.%-0.010wt.% Al and/or Zr content in inoculated irons. It was found that iron powder addition promotes austenite dendrite formation in eutectic and slightly eutectic, acting as reinforcement for the eutectic cells. But, there is an accompanying possible negative influence on the characteristics of the (Mn,X)S type graphite nuclei (change the morphology of nuclei from polygonal compact to irregular polygonal, and therefore promote chill tendency in treated irons). A double addition (iron powder + inoculant

  12. Assessing the effect of copper additions on the corrosion behaviour of grey cast iron

    Directory of Open Access Journals (Sweden)

    Saliu Ojo SEIDU

    2015-05-01

    Full Text Available In this research work, the effect of copper additions on the corrosion behaviour of grey cast iron in 3.5 wt% NaCl, 0.3M H2SO4, and 0.1M NaOH respectively was investigated. Grey cast iron samples containing 3.0%, 2.5%, 2.0%, and 1.5% weight percent of copper were produced. The corrosion behaviour of the grey cast iron samples produced were assessed using mass loss and corrosion rate measurements according to America Society for Testing and Materials standard (ASTM procedures in salt water, basic, and acidic environments. The results reveal that the samples containing 2.0% and 1.5% weight percent of copper show an excellent corrosion resistance while samples containing 3.0% and 2.5% weight percent of copper show good corrosion behaviour all in salt water and basic environments but poorly in acidic environment.

  13. The role of graphite morphology and matrix structure on low frequency thermal cycling of cast irons

    Indian Academy of Sciences (India)

    S Y Buni; N Raman; S Seshan

    2004-02-01

    Low frequency thermal cycling tests were carried out on four types of cast iron (viz., austempered ductile iron, pearlitic ductile iron, compacted/vermicular graphite iron and grey cast iron) at predetermined ranges of thermal cycling temperatures. The specimens were unconstrained. Results show that austempered ductile iron has the highest thermal cycling resistance, followed by pearlitic ductile iron and compacted graphite iron, while grey cast iron exhibits the lowest resistance. Microstructural analysis of test specimens subjected to thermal cycling indicates that matrix decomposition and grain growth are responsible for the reduction in hardness while graphite oxidation, de-cohesion and grain boundary separation are responsible for the reduction in the modulus of elasticity upon thermal cycling.

  14. Chromium and copper influence on the nodular cast iron with carbides microstructure

    Directory of Open Access Journals (Sweden)

    G. Gumienny

    2010-10-01

    Full Text Available In this paper chromium to 1,00% and copper to 1,50% influence at constant molybdenum content of about 1,50% on the nodular cast ironwith carbides microstructure has been presented. It was found, that as a result of synergic addition of above-mentioned elements there isthe possibility obtaining an ausferrite in nodular cast iron with carbides castings. Conditions have been given, when in nodular cast iron with carbides at cooling at first in the form, then air-cooling austenite transformation to upper bainite, its mixture with lower bainite, martensite or ausferrite takes place. Transformations proceed during cooling and the crystallization of cast iron have been determined and the casting hardness has been presented.

  15. Optimization of the Chemical Composition of Cast Iron Used for Casting Ball Bearing Grinding Disks

    Institute of Scientific and Technical Information of China (English)

    Aurel Crisan; Sorin Ion; Munteanu; Ioan Ciobanu; Iulian Riposan

    2008-01-01

    The chemical composition of cast iron used for casting ball bearing machining disks was varied to optimize the properties such as castability, hardenability, and durability in ball machining. The cast iron characteristics were most strongly dependent on the Ni content and the carbon saturation degree, So. This paper describes the types of test specimens, the working conditions, and the experimental results. The in-crease of the degree of carbon saturation reduces the tendency to form shrinkholes in the castings. The de-crease in the Ni content negatively affects the final hardening treatment. A way to control solidification de-fects in cast iron, by reducing the Ni content, has been verified on cast disks.

  16. Microstructure and Mechanical Properties of the Butt Joint in High Density Polyethylene Pipe

    Directory of Open Access Journals (Sweden)

    Pashupati Pokharel

    2016-01-01

    Full Text Available The microstructure and mechanical properties of the butt joint in high density polyethylene (HDPE pipes were evaluated by preparing the joints with increasing the cooling time from 10 s to 70 s before pressure created for fusion of the pipes. Here, cold fusion flaws in HDPE butt joint were created with increasing the cooling time around 70 s caused by the close molecular contact followed by insufficient interdiffusion of chain segments back and forth across the wetted interface. The tensile failure mechanism of the welded pipes at different fusion time was projected based on the tensile test of dog-bone shaped, fully notched bar type as well as round U-notched specimens. The mechanical properties of the joints at different fusion time were correlated with the corresponding fracture surface morphology. The weld seam as well as tensile fracture surfaces were etched using strong oxidizing agents. The crystallinity of surface etched weld zone by potassium permanganate based etchant was found higher than unetched sample due to the higher susceptibility of amorphous phase of polyethylene with oxidizing agent. The U-notched tensile test of butt welded HDPE pipe and surface etching of the weldments provided clear delineation about the joint quality.

  17. Effect of boron carbide on primary crystallization of chromium cast iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2008-04-01

    Full Text Available In the paper results of the influence of boron carbide (B4C as inoculant of abrasion-resisting chromium cast iron (about 2,8% carbon and 18% chromium on primary crystallization researches are presented. Boron carbide dispersion was introduced at the bottom of pouring ladle before tap of liquid cast iron. In this investigations were used three different quantities of inoculant in amounts 0,1%; 0,2% and 0,3% with relation to bath weight. It has been demonstrated that such small additions of boron carbide change primary crystallization parameters, particularly temperature characteristic of process, their time and kinetics.

  18. Draft ASME code case on ductile cast iron for transport packaging

    Energy Technology Data Exchange (ETDEWEB)

    Saegusa, T. [Central Research Inst. of Electric Power Industry, Abiko (Japan); Arai, T. [Central Research Inst. of Electric Power Industry, Yokosuka (Japan); Hirose, M. [Nuclear Fuel Transport Co., Ltd., Tokyo (Japan); Kobayashi, T. [Nippon Chuzo, Kawasaki (Japan); Tezuka, Y. [Mitsubishi Materials Co., Tokyo (Japan); Urabe, N. [Kokan Keisoku K. K., Kawasaki (Japan); Hueggenberg, R. [GNB, Essen (Germany)

    2004-07-01

    The current Rules for Construction of ''Containment Systems for Storage and Transport Packagings of Spent Nuclear Fuel and High Level Radioactive Material and Waste'' of Division 3 in Section III of ASME Code (2001 Edition) does not include ductile cast iron in its list of materials permitted for use. The Rules specify required fracture toughness values of ferritic steel material for nominal wall thickness 5/8 to 12 inches (16 to 305 mm). New rule for ductile cast iron for transport packaging of which wall thickness is greater than 12 inches (305mm) is required.

  19. THE INFLUENCE OF CHEMICAL COMPOSITION OF HIGH-CHROMIUM CAST IRONS ON THE MACHINABILITY

    Directory of Open Access Journals (Sweden)

    V. V. Netrebko

    2016-02-01

    Full Text Available Purpose. This research is aimed to obtain the regression dependence of the machinability on the chemical composition of pig iron (C, Cr, Mn and Ni in cast state. Methodology. The method of active experiment planning was used to build a mathematical model. Cast irons of composition 1.09…3.91 % С; 11.43…25.57 % Cr; 0.6…5.4 % Mn; 0.19…3.01 % Ni were studied. Cutting tools with plates 10х10 mm out of ВК8 according to State Standard 19051-80 were used for turning. Cutting modes: cutting depth – 0.8 mm, longitudinal feed – 0.15 mm/rot., spindle’s rotation frequency during turning – 200…360 rot./min. Lubricating and cooling liquids were not applied. Evaluation of iron workability was produced by determining the linear tool flank wear per unit length of the cutting path. Findings. Mathematically probabilistic equation of the regression dependence of the cutting tool’s wear on the C, Cr, Mn and Ni content in the machined cast iron were obtained. It was established that with the increase of Cr content in the cast iron to 14.8 % the cutting tool’s wear decreased as a result of formation of carbide eutectic which destroyed the doped ledeburite continuous frame. Further increase of chromium content promoted appearing of chromic carbides with high microhardness which considerably increased the tool’s wear. The conducted research shown that the minimum cutting tool’s wear 0,18 mkm/m was observed during the machining of cast iron containing: 1.09 % C, 14.8 % Cr, 2.3 % Mn and 1.2 % Ni; and the maximum wear is 48,96 mkm/m – when the content was: 3.91 % C, 11.43 % Cr, 5.4 % Mn and 0.19 % Ni. The tool’s wear reached 47.61 mkm/m during the treatment of cast iron containing 3.91 % C, 25.57 % Cr, 5.4 % Mn and 0.19 % Ni. Originality. Mathematically probabilistic model of the dependence of the cutting tool’s wear on the C, Cr, Mn and Ni content in the machined cast iron has been elaborated by the author. Practical value. The model

  20. Abrasion Resistance of as-Cast High-Chromium Cast Iron

    Directory of Open Access Journals (Sweden)

    Pokusová Marcela

    2014-12-01

    Full Text Available High chromium cast irons are widely used as abrasion resistant materials. Their properties and wear resistance depend on carbides and on the nature of the matrix supporting these carbides. The paper presents test results of irons which contain (in wt.% 18-22 Cr and 2-5 C, and is alloyed by 1.7 Mo + 5 Ni + 2 Mn to improve the toughness. Tests showed as-cast irons with mostly austenitic matrix achieved hardness 36-53 HRC but their relative abrasion-resistance was higher than the tool steel STN 19436 heat treated on hardness 60 HRC.

  1. Directional solidification of flake and spheroidal graphite cast iron in low and normal gravity environment

    Science.gov (United States)

    Hendrix, J. C.; Stefanescu, D. M.; Curreri, P. A.

    1987-01-01

    A NASA KC-135 research aircraft, flying repeated low-g trajectories that yield 20-30 sec of 0.1-0.001 g microgravity, has been used to study microgravity solidification's elimination of sedimentation and convection (with formation of unique and advantageous microstructures) for the case of eutectic-composition cast irons. The solidification interface of hypereutectic flake and spheroidal graphite cast irons has been slowly advanced through a 4 mm-diameter rod sample. Sample solidification rates have been correlated with accelerometer data, while independently controlling thermal gradients and solidification rates.

  2. The low-aluminium cast iron of reduced silicon content treated with cerium mischmetal

    OpenAIRE

    M. S. Soiński; P. Susek; Hübner, K.; P. Mierzwa

    2008-01-01

    The work presents the effect of cerium mischmetal used in quantities of 0.1 and 0.2 wt-% and ferrosilicon used in quantities from 0.5% to 1.5% on the alloy matrix and the shape of graphite precipitates in the low-aluminium cast iron from seven heats, basing on the examination of its structure. The hypereutectic cast iron of the relatively high carbon content (4.0÷4.2%) at the prior-to-treatment silicon and manganese content equal to ca. 0.6% and ca. 0.04%, respectively, has been examined.It h...

  3. Abrasive Wear Behavior of High Chromium Cast Iron and Hadfield Steel-- A Comparison

    Institute of Scientific and Technical Information of China (English)

    Mehdi Mazar Atabaki; Sajjad Jafari; Hassan Abdollah-pour

    2012-01-01

    Wear properties of two different crushers used for grinding raw materials of cement industry are compared using pin-on-disk wear test.The wear test was carried out with different loads on a pin.Abrasive wear behavior of two alloys was evaluated by comparing mass loss,wear resistance,microhardness and friction coefficient.The microstructure of the specimens was detected using optical microscope.The results showed that abrasive wear of high chromium cast iron is lower than that of Hadfield steel.Due to the presence of M7C3 carbides on the high chromium cast iron matrix,impact crushers exhibited higher friction coefficient

  4. Laser powder surfacing of the Si-Mo spheroidal cast iron with nickel powder

    OpenAIRE

    Klimpel, A; L.A. Dobrzański

    2006-01-01

    Purpose: Investigation results are presented of the effect of main parameters of laser powder surfacing of the Si-Mo spheroidal cast iron with the nickel based powder on quality and shape of padding welds and portion of the substrate material in the padding weld.Design/methodology/approach: It was shown basing on investigation of the process of laser powder surfacing with the nickel based powder onto the spheroidal cast iron substrate that it is feasible to make high quality padding welds in ...

  5. The Influence of Saturation of Cast Iron Austenite with Carbon on the Ausferrite Transformation

    OpenAIRE

    T. Giętka; T. Szykowny; S. Dymski

    2007-01-01

    Austenitizing during quench hardening of the ductile cast iron influences the content of carbon in austenite depending on the soaking heat. On the other hand, the saturation of austenite impacts its transformation in the ausferritizing process of a metal matrix and forming of microstructure. Ductile cast iron with the ferrite matrix was hardened with isothermal transformation in the range of ausferritizing in temperature tpi = 400 i 300 0C and the range of time τpi = 7,5 �� 240 min. Specimens...

  6. INVESTIGATION OF EFFICIENCY OF GRAY CAST IRON GRAPHITIZING MODIFICATION BY DISPERSION-FILLED CONSUMABLE PATTERN

    Directory of Open Access Journals (Sweden)

    I. A. Nebozhak

    2016-01-01

    Full Text Available The key criteria of the process of graphitizing modification of matrix melt silicon concentration and silicon assimilation evaluated were on samples of gray cast iron grade СЧ20 State Standard 1412-85. These criteria of evaluation on the structure and properties of casting ingots proved an efficiency of intra-mold modification of molten gray cast iron by dispersed ferrosilicon grade ФС75 State Standard 1415-93 (ISO 5445-80 using lost-foam casting (LFC-process.

  7. Long term stability analysis of cast iron shaft linings after Coal Mine closure and flooding

    Energy Technology Data Exchange (ETDEWEB)

    Hadj-Hassen, F. [Ecole des Mines de Paris - CGES, 77 - Fontainebleau (France); Bienvenu, Y. [Ecole des Mines de Paris, CM, 91 - Evry (France); Noirel, J.F. [Charbonnages de France, DTN, 57 - Freyming Merlebach (France); Metz, M. [charbonnages de France, ESA, 57 - Freyming Merlebach (France)

    2005-07-01

    This paper presents the results of a study conducted to analyse the long term stability of the cast iron shaft lining after coal mine closure and flooding. The attention is mainly focused on the behaviour during the critical phase of flooding as well as the phase corresponding to the disappearance of the water pressure and the stabilization of the environment. This pluri-disciplinary study was conducted by a team combining specialists in rock mechanics who identified the main risks and the conditions of stability of the lining and specialists in metallurgy who studied the composition of the cast iron and its corrosion behaviour after exposure to mine water. (authors)

  8. Microstructure, Impact Fatigue Resistance and Impact Wear Resistance of Wear Resistant Low Cr-Si Cast Iron

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A great amount of iron and steel has been consumed in impact wear resistance parts such as grinding balls and lining plates in tube mills. Under this working conditions, the failure of wear resistant white irons is generally caused by fatigue spalling. The martensitic high chromium cast iron (WCr=15 %) has good wear resistance, but its cost is higher. The impact wear resistance of low chromium cast iron sometimes is not good. In the present paper ,a new wear resistant material-low Cr-Si cast iron was introduced. The influence of microstructure of cast iron on impact fatigue resistance and impact wear resistance was discussed. The ball-on-ball impact fatigue test, the high stress impact wear test and the field test of the grinding balls have been carried out. The results showed that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of low Cr-Si cast iron are superior to typical low chromium cast irons and close to the martensitic high chromium cast iron. The main reasons are: ① The as-cast matrix of the low Cr-Si cast iron with stress released is pearlite with better plasticity and toughness; ② The high Si content improves the morphology of eutectic carbide, and has no secondary carbide resulting in less crack sources. All these factors are beneficial to the improvement of impact fatigue spalling resistance and impact wear resistance.

  9. Effect of Nb on Structure and Mechanical Properties of Chilled Cast Iron at Room and Elevated Temperatures

    Institute of Scientific and Technical Information of China (English)

    Qijie ZHAI; Li FU; Huaying ZHAI

    2004-01-01

    Effect of Nb on microstructure and mechanical properties of chilled cast iron at room and elevated temperatures is studied in this research. The results demonstrate that the cast structure and mechanical properties of chilled cast iron at room and elevated temperatures are improved with the addition of trace amount of Nb. However, if Nb was added too much, the cast structure and mechanical properties of chilled cast iron would deteriorate. The suitable content of Nb in chilled cast iron is about 0.05% (mass fraction). Except the dissolution in the matrix of cast iron the excessive Nb will form Nb-rich phases in three morphologies. Those are lumpy NbC, complicated strip-like phase and compound with pearlite structure.

  10. Effect of bionic coupling units' forms on wear resistance of gray cast iron under dry linear reciprocating sliding condition

    Science.gov (United States)

    Pang, Zuobo; Zhou, Hong; Xie, Guofeng; Cong, Dalong; Meng, Chao; Ren, Luquan

    2015-07-01

    In order to get close to the wear form of guide rails, the homemade linear reciprocating wear testing machine was used for the wear test. In order to improve the wear-resistance of gray cast iron guide rail, bionic coupling units of different forms were manufactured by a laser. Wear behavior of gray-cast-iron with bionic-coupling units has been studied under dry sliding condition at room temperature using the wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that bionic coupling unit could improve the wear resistance of gray cast iron. The wear resistance of gray cast iron with reticulation bionic coupling unit is the best. When the load and speed changed, reticulation bionic coupling unit still has excellent performance in improving the wear resistance of gray cast iron.

  11. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Science.gov (United States)

    2010-10-01

    ..., tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel Code... 46 Shipping 2 2010-10-01 2010-10-01 false Circumferential joints in pipes, tubes and headers...) MARINE ENGINEERING POWER BOILERS Requirements for Boilers Fabricated by Welding §...

  12. Grey cast iron as construction material of bridges from the 18th and 19th century

    Directory of Open Access Journals (Sweden)

    J. Rabiega

    2011-04-01

    Full Text Available Many bridges and railroad viaducts, which have been operated at the western and southern regions of Poland, were erected at the end ofthe 18th or beginning of the 19th century. In recent years they undergo overhauls and renovations requiring familiarity with the construction materials they have been made of. It is necessary for estimation of their load capacity (possible reinforcements and determining their suitability for further utilisation. Among the materials in the old bridges the puddled steels and cast irons predominate. Aim of the work is identification and documentation of microstructure and selected properties of the cast irons used for production of parts for the bridge in Łażany, the Old Mieszczański Bridge in Wrocław, the hanging bridge in Ozimek, as well as the columnar piers of the railroad viaduct in Wrocław. Using the methods of light microscopy and scanning electron microscopy, as well as the results of hardness measurements and chemical analysis, it has been shown that the objects have been built of grey cast iron with flake graphite having the ferritic-pearlitic or pearlitic matrix. The diversification of their chemical analysis resulting from the type, size and geometry of the cast parts was indicated.The tested materials fulfil requirements of the contemporary standards related to grey cast irons of the EN-GJL-100 and EN-GJL-150grades.

  13. STUDY ON THE MECHANISM OF GRAPHITIZATION IN MOLTEN CAST IRON PROMOTED BY ELECTROPULSE DISCHARGE

    Institute of Scientific and Technical Information of China (English)

    G.W. Chang; J.S. Wang; J.Z. Wang; Q.G. Xue; D.Q. Zhou; D.Q. Cang

    2004-01-01

    From the points of both molten cast iron structure and the appearing ratio of electrons in outer-layer of different atoms, analysis on enhancement mechanism of graphitization ability after processing of the iron by pulse electric discharge has been made, and the theory has been proofed by corresponding experiments. The results show that when the molten cast iron is being processed by pulse electric discharge, both the size of crystal embryos that composed by Fe and C atoms as well as the number of clusters can bereduced, even be separated by such discharging; consequently results in the segregation of C atoms in the molten cast iron near the cathode of discharging. The nucleation of graphite in these areas of the iron has been promoted at the discharging temperature; even though such degree has not been reached, the most favorable nucleation conditions of graphite can be at least created. Under the preconditions of not breaking up the graphite crystal embryos, with proper adjustment of discharging frequency, the stronger of the electric field and the longer of the pulsation treatment time are, the more graphitization ability of the molten cast iron is. The theoretical analysis on the above rules consists well with experimental results.

  14. Influence of rare earths on shrinkage porosity in thin walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2009-01-01

    Ductile cast iron has been cast in test bars with thickness from 2 to 10 mm. The rare earth elements La and Ce have been added to some of the castings to evaluate their influence on microstructure and shrinkage tendency. Both La and Ce increased the graphite nodule count, especially for thickness...

  15. CONTINUOUSLY-CYCLIC CASTING OF HOLLOW CYLINDER SLUGS OF HIGH-CHROMIUM CAST IRON

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2009-01-01

    Full Text Available The analysis of castings formation is presented and the package of measures dircted on increase of stability of casting process is developed. Parametres of casting of hollow cylindrical billets by the method of directional solidification out of white high-chromium cast iron are defined.

  16. Modelling the solidification of ductile cast iron parts with varying wall thicknesses

    DEFF Research Database (Denmark)

    Bjerre, Mathias Karsten; Tiedje, Niels Skat; Thorborg, Jesper;

    2015-01-01

    a 2D FE solution of the heat conduction equation is developed in an in-house code and model parameters are calibrated using experimental data from representative castings made of ductile cast iron. The main focus is on the influence of casting thickness and resulting local cooling conditions on the...

  17. Numerical modelling of thin-walled hypereutectic ductile cast iron parts

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Hattel, Jesper Henri; Tiedje, Niels Skat

    2006-01-01

    Solidification of hypereutectic thin-walled ductile cast iron has been modelled in one dimension taking into account the precipitation of off-eutectic austenite dendrites during solidification. The simulations have been compared with casting experiments on plate geometries with plate thicknesses...

  18. Characteristics of flake graphite in Ni-Mn-Cu cast iron. Part 2.

    Directory of Open Access Journals (Sweden)

    A. Janus

    2010-01-01

    Full Text Available The paper continues the article published by Archives of Foundry Engineering, vol. 9, issue 1/2009, pp. 185-290, that presented influence of chemical composition of hypo- and hypereutectic nickel-manganese-copper alloyed cast iron on properties of the contained flake graphite. In this second part of the research, effect of chemical composition of hypereutectic cast iron containing 3.5÷5.1% C, 1.7÷2.8% Si, 3.5÷10.5 %Ni, 2.0÷8.0% Mn, 0.1÷3.5% Cu, 0.14÷0.17% P and 0.02÷0.04% S on properties of flake graphite is determined. Evolution of graphite properties with changing eutecticity degree of the examined cast iron is presented. For selected castings, histograms of primary and eutectic graphite are presented, showing quantities of graphite precipitates in individual size ranges and their shape determined by the coefficient ξ defined as ratio of a precipitate area to square of its circumference. Moreover, presented are equations obtained by discriminant analysis to determine chemical composition of Ni-Mn-Cu cast iron which guarantee the most favourable distribution of A-type graphite from the point of view of castings properties.

  19. FORMATION OF WEAR-RESISTANT CHROMIUM CAST IRON CASTING INTO THE CHILL MOLD

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2013-01-01

    Full Text Available The analysis of thermal processes of formation of castings from wearproof chromic cast irons for replaceable details of centrifugal mills and crushers is carried out. Influence of protective and dividing coverings on intensity of heating of the chill mold is investigated.

  20. Investigation of jatropha seed oil as austempering quenchant for ductile cast iron

    Directory of Open Access Journals (Sweden)

    Akor Terngu

    2014-06-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Austempering is a multi-step process that includes austenitizing, followed by cooling rapidly enough to avoid the formation of pearlite to a temperature above the martensite start (Ms and then holding until the desired microstructure is formed. It is an isothermal heat treatment process that, when applied to cast iron, produces components that, in many cases, have properties superior to those process by conventional heat treatment. Salt bath has been recognized as the conventional quenching medium for austempering. This study investigates the suitability of jatropha seed oil as quenching medium for asaustempering ductile cast iron. Test samples were austenitized at 9500C; socked for 1hr; austempered for varying periods of 1, 2, 3, 4 and 5hrs. The result showed significant increase in tensile strength and impact energy apart from achieving an appreciable increase in hardness. It also tally with recommended values of ductile cast iron austempered in salt bath, implying that jatropha oil can be used as hot bath for the austempering of ductile cast iron. Keywords: Ausferrite, Austempering, Austenitized, Matrix So, Cked.

  1. Numerical modeling of coupled heat transfer and phase transformation for solidification of the gray cast iron

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Hosseinzadeh, Azin

    2013-01-01

    In the present study the numerical model in 2D is used to study the solidification bahavior of the gray cast iron. The conventional heat transfer is coupled with the proposed micro-model to predict the amount of different phases, i.e. total austenite (c) phase, graphite (G) and cementite (C), in...

  2. Application of ultrasound in testing of heat-treated cast iron

    Directory of Open Access Journals (Sweden)

    Mróz, M.

    2007-01-01

    Full Text Available The paper is an attempt to clarify the effect of heat treatment on the cast iron structure and propagation of ultrasonic waves in it with the objective of showing the usability of this technique for diagnosis of heat treatment effects.

  3. Influences of copper on solidification structure and hardening behavior of high chromium cast irons

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; XIONG Ji; FAN Hong-yuan; SHEN Bao-luo; GAO Sheng-ji

    2008-01-01

    The influences of copper on microstructure and the hardening behavior of high chromium cast irons subjected to sub-critical treatment were investigated.The results show that the mierostructure of the as-cast high chromium cast irons consists of retained austenite,martensite and M7 C3 type eutectic carbide.When copper is added into high chromium cast irons,austenite and carbide contents are increased.The increased addition of copper content from 0%to 1.84%leads to the increase of austenite and carbide from 15.9%and 20.0% to 61.0%and 35.5%,respectively.In the process of sub-critical treatment,the retained austenite in the matrix can be precipitated into secondary carbides and then transforms into martensite in cooling process,which causes the secondary hardening of the alloy under sub-critical treatment.High chromium cast irons containing copper in sub-critical treatment appear the second hardening curve peak due to the precipitation of copper from supersaturated matrix.

  4. The influence of chosen modifiers on stereological parameters of carbides of chromium cast iron

    OpenAIRE

    A. Studnicki; J. Suchoń

    2011-01-01

    The results of investigations of stereological carbides in the modified wear resistance chromium cast iron resistant were introduced in the article. There were following elements: boron, niobium, vanadium, cerium and lanthanum (RE), nitrogen in the composition of modifiers. The influence of used modifiers on such stereological parameters of carbides as: size, perimeter, shape coefficient and volume fraction was showed in tables and on diagrams.

  5. Composite Materials Processing of Cast Iron and Ceramics Using Compo-Casting Technology

    Science.gov (United States)

    Tomita, Yoshihiro; Sumimoto, Haruyoshi

    The compo-casting technology of ceramics and cast iron is expected to be one of the major casting technologies that can expand the application fields of cast iron. This technique allows the heat energy of the molten metal to be utilized to produce cast iron products which are added with functions of ceramic materials. The largest problem in compo-casting technology is generation of cracks caused by thermal shock. Although this crack generation can be prevented by reducing the thermal stress by means of preheating ceramics, the necessary preheating temperature is considerably high and its precise controlling is difficult at the practical foundry working sites. In this study, we tried to numerically predict the critical preheating temperature of ceramics using the thermal stress analysis in unsteady heat transfer and the Newman's diagram, and found that the preheating of ceramics to reduce thermal stress could be substituted with placing an appropriate cast iron cover around the ceramics. Excellent results were obtained by using a method whereby a ceramic bar was covered with a flake graphite cast iron cover and fixed in a sand mold and then molten metal was poured. Then, two or three ceramics were examined at the same time under the compocasting condition. As a result, three specimens could be done at the same time by adjusting the cover space to 15mm. Moreover, irregular shape ceramics were examined under the compocasting condition. As a result, the compocasting could be done by devising the cover shape. In each condition, it was confirmed that the cover shape made from the analytical result was effective to the compocasting by doing the thermometry of the specimens.

  6. Removal of arsenate and arsenite from aqueous solution by waste cast iron

    Institute of Scientific and Technical Information of China (English)

    Nag-Choul Choi; Song-Bae Kim; Soon-Oh Kim; Jae-Won Lee; Jun-Boum Park

    2012-01-01

    The removal of As(Ⅲ) and As(Ⅴ) from aqueous solution was investigated using waste cast iron,which is a byproduct of the iron casting process in foundries.Two types of waste cast iron were used in the experiment:grind precipitate dust (GPD) and cast iron shot (CIS).The X-ray diffraction analysis indicated the presence of Fe0 on GPD and CIS.Batch experiments were performed under different concentrations of As(Ⅲ) and As(Ⅴ) and at various initial pH levels.Results showed that waste cast iron was effective in the removal of arsenic.The adsorption isotherm study indicated that the Langmuir isotherm was better than the Freundlich isotherm at describing the experimental result.In the adsorption of both As(Ⅲ) and As(Ⅴ),the adsorption capacity of GPD was greater than CIS,mainly due to the fact that GPD had higher surface area and weight percent of Fe than CIS.Results also indicated the removal of As(Ⅲ) and As(Ⅴ)by GPD and CIS was influenced by the initial solution pH,generally decreasing with increasing pH from 3.0 to 10.5.In addition,both GPD and CIS were more effective at the removal of As(Ⅲ) than As(Ⅴ) under given experimental conditions.This study demonstrates that waste cast iron has potential as a reactive material to treat wastewater and groundwater containing arsenic.

  7. Fatigue behaviour and energy dissipation of a nodular cast iron in ultrasonic fatigue loading

    Directory of Open Access Journals (Sweden)

    H.Q. Xue

    2006-08-01

    Full Text Available Purpose: In the current research, fatigue tests of cast iron (GS51 have been conducted using the ultrasonicfatigue system and monitored by an advanced infrared imaging system in real time. Fatigue damage processeshas been observed and analyzed. Furthermore, heat condition effect has been to analyze.Design/methodology/approach: Fatigue behaviour in the very high cycle regime of 1010 cycles wereinvestigated with a cast iron (GS51 under ultrasonic fatigue test system in ambient air at room temperaturewith a stress ratio R=-1. The influence of frequency was examined by comparing similar data generated onconventional servo hydraulic test systems. An infrared camera was also used to record specimen temperaturesat various load levels caused by internal damping due to cycling at a very high frequency.Findings: The S-N curves obtained show that fatigue failure occurred beyond 109 cycles, fatigue limit does notexist for the cast iron and there is no evidence of frequency effect on the test results. A detailed study on fatiguespecimens subjected to ultrasonic frequency shows that the temperature evolution of the cast iron specimen isvery evident, the temperature increased just at the beginning of the test, the temperature increased depending onthe maximum stress amplitude.Research limitations/implications: Ultrasonic fatigue test methodology had been applied extensively inexploring fatigue lives at very high cycle regime. However, it is a predominant problem that the thermal energydissipation results in increasing of temperature of specimen at very high frequency fatigue experiment. In orderto investigate the heat dissipation of ultrasonic fatigue specimen and understand the influence of temperatureevolution on the fatigue properties, it is necessary to obtain the temperature response of vibratory specimen.Originality/value: Early stage of damage of the cast iron which lead to crack initiation and micro crack growthare characterized by local microstructure

  8. A repair process for an heterogenous welded joint between a nuclear reactor component tube and a pipe

    International Nuclear Information System (INIS)

    The repairing process involves cutting a tubular section of the tube (made of low alloy steel) and the pipe (made of austenitic stainless steel), which includes the welded joint, and preparing an heterogenous tubular section for substitution (a first section, made of ferritic steel, is butt welded to a second section, made of austenitic stainless steel); the tubular section is then narrow-joint welded with the low-alloy steel tube, and finally welded to the austenitic stainless steel pipe. Application to repairing a welded joint between a pressurizer tube and an expansion pipe connected to the primary circuit. (author). 5 refs., 4 figs

  9. Mechanical pipe couplings. The alternative jointing method for PE gas pipes up to 10 bar; Mechanische Rohrkupplungen. Die alternative Verbindung fuer PE-Gas-Rohre bis 10 bar

    Energy Technology Data Exchange (ETDEWEB)

    Kroeger, Axel; Johnson, Alexander [PSI Products GmbH, Moessingen (Germany)

    2010-11-15

    Increasing competition nowadays obliges natural gas suppliers to adopt continuous cost-optimization. Many utilities are therefore rethinking their existing methods for jointing of plastic pipes. Around the world, mechanical pipe couplings are becoming established in this field as a rational-cost, safe and easy-to-install alternative to conventional welding methods. For this project, PSI Products GmbH and Elster Perfection are pursuing new routes for the development of solutions to problems in plastic-pipe jointing technology. As a specialist in accessories for the field of pipeline engineering, PSI Products GmbH has now also unveiled, in the form of the Permasert {sup registered} and PermaLock {sup registered} pipe-coupling and jointing systems, a complete product range, with DVGW approval, for mechanical jointing of gas supply pipelines for the German natural gas market. This system has proven its capabilities since its market launch in the USA more than thirty years ago, and is now one of the world's most widely used mechanical PE-pipe jointing methods. Simple and fast installation is the basis of this success. More than 45 million Permasert {sup registered} couplings and PermaLock {sup registered} tapping valves are now in use under virtually all conceivable climatic and soil conditions, and not only in North America and Europe, but also in Asia, Australia, the Middle East, and Central and South America. (orig.)

  10. Operation reliability of plasma arc-welded joints for NPP pipings

    International Nuclear Information System (INIS)

    A technology has been developed of plasma-arc welding joints of pipe of steel 12Kh18N10T to replace the factory welding technology using the electrodes EA-400/10 t. It is established that the decisive influence of the formation and microcontinuity of the welded joint is produced by satisfying the optimum values of current and welding rate. Deviation from these values results in nonpenetrations and burnings. A study has been made of the welded joint strength properties at temperatures of 20, 200, 350 deg C and low-cycle fatigue at 350 deg C. The joints made by plasma-arc welding are shown to have higher cyclic strength and resistance to brittle fracture than those made by the former technology

  11. China and Malaysia Launch Joint Venture for Oil Pipes in Shanghai

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ The largest oil companies of China and Malaysia,PetroChina and UMW, launched a joint venture - B SW Petropipe Company - in Shanghai on May 30, 2004, just one day following Malaysia's decision to recognize China as a full market economy. This joint venture, in which PetroChina holds a 51 percent stake while UMW takes up the remaining 49 percent, is expected to be the major supplier of oil and gas pipelines in East China, with a projected annual output of 300,000 tons for steel pipes of various kinds.

  12. Structure and mechanical properties of the welded joints of large-diameter pipes

    Science.gov (United States)

    Khotinov, V. A.; Arabei, A. B.; Pyshmintsev, I. Yu.; Farber, V. M.

    2013-05-01

    The structure and mechanical properties of the technological welded joints of large-diameter pipes of strength class K60 produced by two companies are studied. Along with standard mechanical properties (σ0.2, σu, δ, ψ), specific work of deformation a (tensile toughness) and true rupture strength S f are estimated from an analysis of the stress-strain diagrams constructed in true coordinates. The mechanical behavior is found to be different for samples cut from different zones of a welded joint (central weld, heat-affected zone, and base metal). The mutual correlation between parameters a, S f, and impact toughness KCV is considered.

  13. Eddy-current inspection of welded joints of electro-welded pipes with using measurement result visualization

    International Nuclear Information System (INIS)

    Results on experimental studies of welded joints of electro-welded pipes with artificial defects through eddy currents are presented. Decoding and graphical interpretation of testing results are carried out through the computerized visualisation system of eddy currents signals converters. Possibility of evaluating the quality of pipe welding with eddy currents images decoding is shown. 8 refs., 3 figs

  14. Source location of artificial acoustic emission in elbow-pipe joint using neural network

    International Nuclear Information System (INIS)

    A new technique to locate a defect, combining acoustic emission (AE) and neural network, is proposed to assess the structural integrity of a pipeline in operation. Computer simulations and experiments to locate the defect using artificial AE by means of a pencil lead break are conducted at an elbow-pipe joint. Arrival time differences of the AE wave from the AE source to four sensors with 150kHz resonance frequency are measured using an AE digital measuring system with four channel devices. Half the data and all data are used for leaning of the neural network and for estimating the locations, respectively. Source location error of the elbow-pipe joint in the experiment, as well as the simulation, was less than 1%. To confirm the detection of a crack extension in a pipe joint by the system, crack tip locations due to extension are obtained from a welded defect of a tensile specimen are determined. Results are obtained for the detection of the crack extension. (author)

  15. Source location of artificial acoustic emission in elbow-pipe joint using neural network

    Energy Technology Data Exchange (ETDEWEB)

    Homma, Kyoji; Okamura, Yuka [The Univ. of Electro-communications, Chofu, Tokyo (Japan)

    2002-11-01

    A new technique to locate a defect, combining acoustic emission (AE) and neural network, is proposed to assess the structural integrity of a pipeline in operation. Computer simulations and experiments to locate the defect using artificial AE by means of a pencil lead break are conducted at an elbow-pipe joint. Arrival time differences of the AE wave from the AE source to four sensors with 150kHz resonance frequency are measured using an AE digital measuring system with four channel devices. Half the data and all data are used for leaning of the neural network and for estimating the locations, respectively. Source location error of the elbow-pipe joint in the experiment, as well as the simulation, was less than 1%. To confirm the detection of a crack extension in a pipe joint by the system, crack tip locations due to extension are obtained from a welded defect of a tensile specimen are determined. Results are obtained for the detection of the crack extension. (author)

  16. Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

    Institute of Scientific and Technical Information of China (English)

    HAO Jian-jun; MA Yue-jin; SHEN Yu-zeng

    2004-01-01

    Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.

  17. Automatic quantitative analysis of microstructure of ductile cast iron using digital image processing

    Directory of Open Access Journals (Sweden)

    Abhijit Malage

    2015-09-01

    Full Text Available Ductile cast iron is preferred as nodular iron or spheroidal graphite iron. Ductile cast iron contains graphite in form of discrete nodules and matrix of ferrite and perlite. In order to determine the mechanical properties, one needs to determine volume of phases in matrix and nodularity in the microstructure of metal sample. Manual methods available for this, are time consuming and accuracy depends on expertize. The paper proposes a novel method for automatic quantitative analysis of microstructure of Ferritic Pearlitic Ductile Iron which calculates volume of phases and nodularity of that sample. This gives results within a very short time (approximately 5 sec with 98% accuracy for volume phases of matrices and 90% of accuracy for nodule detection and analysis which are in the range of standard specified for SG 500/7 and validated by metallurgist.

  18. Characteristics of flake graphite in Ni-Mn-Cu cast iron. Part 2.

    OpenAIRE

    Janus, A.

    2010-01-01

    The paper continues the article published by Archives of Foundry Engineering, vol. 9, issue 1/2009, pp. 185-290, that presented influence of chemical composition of hypo- and hypereutectic nickel-manganese-copper alloyed cast iron on properties of the contained flake graphite. In this second part of the research, effect of chemical composition of hypereutectic cast iron containing 3.5÷5.1% C, 1.7÷2.8% Si, 3.5÷10.5 %Ni, 2.0÷8.0% Mn, 0.1÷3.5% Cu, 0.14÷0.17% P and 0.02÷0.04% S on properties of f...

  19. Physicochemical studies of glucose, gellan gum, and hydroxypropyl cellulose--inhibition of cast iron corrosion.

    Science.gov (United States)

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy

    2013-06-01

    Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied. The addition of potassium iodide to the corrosion-inhibition system showed both antagonism and synergism toward inhibition efficiency. Polarization studies revealed the mixed-type inhibiting nature of the carbohydrates. The adsorption of inhibitors on the cast iron surface obeys Langmuir adsorption isotherm model, both in presence and absence of KI. Physical interaction between the inhibitor molecules and the iron surface was suggested by the thermochemical parameters, rather than chemical interaction.

  20. Corrosion Inhibition of Cast Iron in Arabian Gulf Seawater by Two Different Ionic Liquids

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2015-06-01

    Full Text Available In this paper we report on the corrosion inhibition of cast iron in Arabian Gulf seawater by two different ionic liquids namely, 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl and 1-butyl-1-methylpyrrolidinium chloride ([Py1,4]Cl. The inhibiting influence of the employed ionic liquids was investigated by weight loss, open circuit potential electrochemical impedance spectroscopy, and cyclic potentiodynamic polarization. The results show the corrosion inhibition impact of the employed ionic liquids (ILs. Compared with [Py1,4]Cl, [EMIm]Cl shows a higher inhibition efficiency at a short immersion time, for the examined ILs concentrations. However, [Py1,4]Cl exhibits a higher efficiency upon increasing the immersion time indicating the persistence of the inhibiting influence. The corrosion inhibition of the employed ionic liquids is attributed to the adsorption of the cations of the ionic liquids onto the surface of cast iron forming a corrosion barrier.

  1. Influence of Technological Parameters of Furane Mixtures on Shrinkage Creation in Ductile Cast Iron Castings

    Directory of Open Access Journals (Sweden)

    Vasková I.

    2014-10-01

    Full Text Available Ductile cast iron (GS has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.

  2. Ultrasonic cavitation erosion of nodular cast iron with ferrite-pearlite microstructure.

    Science.gov (United States)

    Mitelea, Ion; Bordeaşu, Ilare; Pelle, Marius; Crăciunescu, Corneliu

    2015-03-01

    The cavitation erosion of ductile cast iron with ferrite-pearlite microstructure was analyzed based on ultrasonic experiments performed according to ASTM G32-2010 and the resistance was compared to the C45 steel with similar hardness. The microstructural observation of the surface for different exposure times to the ultrasonic cavitation reveals the fact that the process initiates at the nodular graphite-ferrite interface and is controlled by micro-galvanic activities and mechanical factors. The cavitation erosion resistance was evaluated based on the evolution of the mean depth erosion and the mean depth erosion rate as a function of the cavitation time. The cavitation erosion rate of the cast iron is up to 1.32 times higher than the one of the C 45 steel with similar hardness. This is explained by the occurrence of stress concentrators due to the expulsion of the graphite from the metallic matrix. PMID:25465881

  3. The anaerobic corrosion of carbon steel and cast iron in artificial groundwaters

    Energy Technology Data Exchange (ETDEWEB)

    Smart, N.R. [AEA Technology plc, Culham Science Centre (United Kingdom); Blackwood, D.J. [National Univ. of Singapore (Singapore); Werme, L. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2001-07-01

    In Sweden, high level radioactive waste will be disposed of in a canister with a copper outer and a cast iron or carbon steel inner. If the iron insert comes into contact with anoxic geological water, anaerobic corrosion leading to the generation of hydrogen will occur. This paper presents a study of the anaerobic corrosion of carbon steel and cast iron in artificial Swedish granitic groundwaters. Electrochemical methods and gas collection techniques were used to assess the mechanisms and rates of corrosion and the associated hydrogen gas production over a range of conditions. The corrosion rate is high initially but is anodically limited by the slow formation of a duplex magnetite film. The effects of key environmental parameters such as temperature and ionic strength on the anaerobic corrosion rate are discussed.

  4. 3-D Analysis of Graphite Nodules in Ductile Cast Iron Using FIB-SEM

    DEFF Research Database (Denmark)

    D'Angelo, Luca; Jespersen, Freja N.; MacDonald, A. Nicole;

    Ductile cast iron samples were analysed in a Focused Ion Beam Scanning Electron Microscope, FIB-SEM. The focussed ion beam was used to carefully remove layers of the graphite nodules to reveal internal structures in the nodules. The sample preparation and milling procedure for sectioning graphite...... inside the nodules, their orientation in relation to the graphite and the chemistry of the inclusions is analysed and described. Formation of the structures during solidification and subsequent cooling to room temperature is discussed....

  5. Application of cored wire injection method to the producing of vermicular cast iron

    OpenAIRE

    E. Guzik; T. Kleingartner

    2008-01-01

    Thc rcsults of studies on thc use of magnesium alloy in modcrn cod wire injection method tor pmduction of vcrrniculnr ~rsphitcc astirons were described. The injection of Mg corcd wirc lcngth is a trcatmcnt rnczhod which can bc used lo pmcss iron mcltctl in an clcctricinduction fumacc. This paper describes the results of using a high-magnssiurn fcmsilicon alloy in corcd wire (Mg recovcry 45% ) Tor thcproduction OF vcrmicular graphite cast irons at Gicsserci Hcunisch GmbI I Foundry. Thc rcsulrs...

  6. 46 CFR 56.60-10 - Cast iron and malleable iron.

    Science.gov (United States)

    2010-10-01

    ... and malleable iron fittings conforming to the specifications of 46 CFR 56.60-1, Table 56.60-1(a) may...; see 46 CFR 56.01-2) and if their service does not exceed the rating as marked on the valve. (b) Cast... 46 Shipping 2 2010-10-01 2010-10-01 false Cast iron and malleable iron. 56.60-10 Section...

  7. Fatigue analysis-based numerical design of stamping tools made of cast iron

    OpenAIRE

    Ben Slima, Khalil; Penazzi, Luc; Mabru, Catherine; Ronde-Oustau, François

    2013-01-01

    International audience This work concerns stress and fatigue analysis of stamping tools made of cast iron with an essentially pearlitic matrix and containing foundry defects. Our approach consists at first, in coupling the stamping numerical processing simulations and structure analysis in order to improve the tool stiffness geometry for minimizing the stress state and optimizing their fatigue lifetime. The method consists in simulating the stamping process by considering the tool as a per...

  8. Control of Wear-Resistance Properties in Ti-added Hypereutectic High Chromium Cast Iron

    OpenAIRE

    Liu, Qiang

    2012-01-01

    High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The wear resistance and mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). The Hypereutectic HCCI with large volume fractions of hard carbides is preferred to apply in wear applications. However, the coarser and larger primary M7C3 carbides will be precipitated during the s...

  9. The change of temperature gradient in solidification of hypereutectic chromium cast iron casting

    OpenAIRE

    A. Studnicki

    2010-01-01

    In article the analysis of temperature gradient of solidification in section of hypereutectic chromium cast iron model casting was introduced. On this example was presented the method (DTGA – derivative and thermal gradient analysis), which was worked out in Department of Foundry Silesian University of Technology enabling the record of indispensable data to execution of analysis the temperature gradient and its derivative after time on section of model casting. It multichanneled apparatus to ...

  10. The change of temperature gradient in solidification of hypereutectic chromium cast iron casting

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2010-01-01

    Full Text Available In article the analysis of temperature gradient of solidification in section of hypereutectic chromium cast iron model casting was introduced. On this example was presented the method (DTGA – derivative and thermal gradient analysis, which was worked out in Department of Foundry Silesian University of Technology enabling the record of indispensable data to execution of analysis the temperature gradient and its derivative after time on section of model casting. It multichanneled apparatus to registration of data was used Crystaldigraph - PC.

  11. Microstructure Evaluation and Wear-Resistant Properties of Ti-alloyed Hypereutectic High Chromium Cast Iron

    OpenAIRE

    Liu, Qiang

    2013-01-01

    High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). The hypereutectic HCCI with large volume fractions of hard carbides is preferred to apply in wear applications. However, the coarser and larger primary M7C3 carbides will be precipitated during the solidification of the...

  12. Numerical modelling of thin-walled hypereutectic ductile cast iron parts

    OpenAIRE

    Pedersen, Karl Martin; Hattel, Jesper Henri; Tiedje, Niels Skat

    2006-01-01

    Solidification of hypereutectic thin-walled ductile cast iron has been modelled in one dimension taking into account the precipitation of off-eutectic austenite dendrites during solidification. The simulations have been compared with casting experiments on plate geometries with plate thicknesses from 2.8 to 8.0 mm with good agreement for both cooling curves and nodule counts. The experimental results revealed that the eutectic solidification of plates with thicknesses less than 4.3 mm was cha...

  13. Improving chill control in iron powder treated slightly hypereutectic grey cast irons

    OpenAIRE

    Iulian Riposan; Mihai Chisamera; Stelian Stan

    2011-01-01

    Recent studies revealed that in eutectic to slightly hypereutectic grey irons (CE = 4.3%-4.5%) the presence of austenite dendrites provides an opportunity to improve the cast iron properties, as a high number of eutectic cells are “reinforced” by austenite dendrites. An iron powder addition proved to be important by promoting dendritic austenite in hypereutectic irons, but was accompanied by adverse effect on the characteristics of potential nuclei for graphite. The purpose of the present pap...

  14. Numerical modeling and experimental validation of microstructure in gray cast iron

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Davami, Parviz; Varahram, Naser

    2012-01-01

    To predict the amount of different phases in gray cast iron by a finite difference model (FDM) on the basis of cooling rate (R), the volume fractions of total γ phase, graphite, and cementite were calculated. The results of phase composition were evaluated to find a proper correlation with cooling...... to correlate the phase volume fraction to hardness. The results are compared with experimental data and show reasonable agreement....

  15. ELABORATION OF MANAGEMENT PLAN OF SOLID WASTE FROM SMALL CAST IRON FOUNDRIES

    OpenAIRE

    Carlos Alberto Mendes Moraes; Amanda Gonçalves Kieling; Daiane Calheiro; Daniel Canello Pires; Cynthia Fleming Batalha da Silveira; Ana Cristina de Almeida Garcia; Feliciane Andrade Brehm

    2013-01-01

    The foundry industry contributes to society meeting the demand of metal scrap recycling, but, at the same time, it brings a high risk of environmental impact for its many potentially pollutant wastes. Among these, there are slag and used foundry sand (cold cure molding). Through a survey about the production process of a small cast iron company, the collected data was compiled to determine the organizational setting in terms of generation and segregation of waste. From a complete ...

  16. Application of Averaged Voronoi Polyhedron in the Modelling of Crystallisation of Eutectic Nodular Graphite Cast Iron

    OpenAIRE

    A. A. Burbelko; J. Początek; M. Królikowski

    2013-01-01

    The study presents a mathematical model of the crystallisation of nodular graphite cast iron. The proposed model is based on micro- andmacromodels, in which heat flow is analysed at the macro level, while micro level is used for modelling of the diffusion of elements. The use of elementary diffusion field in the shape of an averaged Voronoi polyhedron [AVP] was proposed. To determine the geometry of the averaged Voronoi polyhedron, Kolmogorov statistical theory of crystallisation was applied....

  17. Electrolytic surface hardening of steel,cast iron and aluminium-bronze

    Institute of Scientific and Technical Information of China (English)

    Suhas Keshav Paknikar

    2006-01-01

    Electrolytic hardening process was developed in USSR in the 1950s. The process was developed but was not commercially exploited. There is no evidence of work done on this process in India. The author has done this original work applied to different materials like steel,cast iron and aluminum-bronze. This paper gives details of microstructural transformations along with hardness value achieved. There is vital scope for this process to become viable for surface hardening and selective hardening of small components.

  18. The Influence of Saturation of Cast Iron Austenite with Carbon on the Ausferrite Transformation

    Directory of Open Access Journals (Sweden)

    T. Giętka

    2007-07-01

    Full Text Available Austenitizing during quench hardening of the ductile cast iron influences the content of carbon in austenite depending on the soaking heat. On the other hand, the saturation of austenite impacts its transformation in the ausferritizing process of a metal matrix and forming of microstructure. Ductile cast iron with the ferrite matrix was hardened with isothermal transformation in the range of ausferritizing in temperature tpi = 400 i 300 0C and the range of time τpi = 7,5 �� 240 min. Specimens were gradually austenitized. They were soaked in the nominal temperature tγ = 950 0C, then precooled to the temperature tγ’ = 850 and 800 0C. Microstructure was investigated, there were also defined the proportion of austenite in the matrix of the cast iron and the content of carbon in it and hardness and impact strength in unnotched specimens. It was stated, that the precooling temperature deciding on the content of carbon in austenite influences kinetics of the ausferritic transformation, the content of carbon in the γ phase and impact strength and, in a less degree, hardness. As a result of gradual austenitizing the cast iron after quench hardening, in some conditions of treatment, reached mechanical properties corresponding, according to the ASTM A 897 standard, with high grades of ADI. Chilling in the range of austenitizing in temperature 850 and 800 0C led to the decrease of carbon in austenite what influenced positively on the matrix microstructure and properties of the ADI. Investigations in this range will be continued.

  19. The influence of chosen modifiers on stereological parameters of carbides of chromium cast iron

    Directory of Open Access Journals (Sweden)

    A. Studnicki

    2011-07-01

    Full Text Available The results of investigations of stereological carbides in the modified wear resistance chromium cast iron resistant were introduced in the article. There were following elements: boron, niobium, vanadium, cerium and lanthanum (RE, nitrogen in the composition of modifiers. The influence of used modifiers on such stereological parameters of carbides as: size, perimeter, shape coefficient and volume fraction was showed in tables and on diagrams.

  20. The forty years of vermicular graphite cast iron development in China (PartⅠ)

    OpenAIRE

    QIU Han-quan; CHEN Zheng-de

    2007-01-01

    In China, the research and development of vermicular graphite cast iron (VGCI) as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences,...

  1. The forty years of vermicular graphite cast iron development in China (Part 2)

    OpenAIRE

    CHEN Zheng-de; QIU Han-quan

    2007-01-01

    In China, the research and development of vermicular graphite cast iron (VGCI) as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences,...

  2. PRINCIPALLY NEW EFFECTIVE CASTING PROCESS OF THE HOLLOW CYLINDRICAL SLUGS OF CAST IRON BY METHOD OF DIRECTIONAL SOLIDIFICATION

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2010-01-01

    Full Text Available The advantages of the new method of the hollow ingots production of cast iron are presented. The thermal state of crystallizer at cyclic temperature influences on its inside face, the ingot hardening and cast iron structure formation in conditions of intensive one-sided heat sink is examined. The comparative data on properties and exploitation characteristics of the parts, produced by different ways of casting is given.

  3. Study on the Thermal Fatigue Behavior of Hot Deformed Wear Resistance Cast Iron and Effect of Carbide

    Institute of Scientific and Technical Information of China (English)

    Dong Litao; Liu Rongchang; Li Xingyuan; Chen Xiuhong

    2007-01-01

    The thermal fatigue behavior of wear resistance cast iron with different quantity of deformation has been investigated. The results show that eutectic carbide is the main location and passage for initiation and extension of thermal fatigue cracks, approving that the more serious, the carbide breaks. The higher thermal fatigue resistance of wear resistance cast iron will be and thermal fatigue fracture belongs mainly to brittleness.

  4. Inlfuence of boron on ferrite formation in copper-added spheroidal graphite cast iron

    Institute of Scientific and Technical Information of China (English)

    Ying Zou; Hideo Nakae

    2014-01-01

    This paper reviews the original work of the authors published recently, describing the inlfuence of B on the matrix of the Cu-added spheroidal graphite cast iron. The effect of Cu has been corrected as a ferrite formation promoter in the matrix of the grey cast iron by the usage of high-purity material. Also, this paper focuses on the ferrite formation and the observation of the Cu distribution in the B-added and B-free Cu-containing spheroidal graphite cast iron. The Cu iflm on the spheroidal graphite can be successfuly observed in the B-free sample using a special etching method. However, in the B-added sample, no Cu iflm could be found, while the secondary graphite was formed on the surface of the spheroidal graphite. The interaction between B and Cu is stressed as a peculiar phenomenon by the employment of a contrast experiment of B and Mn. The heat treatment could make Cu precipitate more signiifcantly in the eutectic cels and in the matrix in the form of large Cu particles because of the limited solubility of Cu.

  5. The low-aluminium cast iron of reduced silicon content treated with cerium mischmetal

    Directory of Open Access Journals (Sweden)

    M. S. Soiński

    2008-07-01

    Full Text Available The work presents the effect of cerium mischmetal used in quantities of 0.1 and 0.2 wt-% and ferrosilicon used in quantities from 0.5% to 1.5% on the alloy matrix and the shape of graphite precipitates in the low-aluminium cast iron from seven heats, basing on the examination of its structure. The hypereutectic cast iron of the relatively high carbon content (4.0÷4.2% at the prior-to-treatment silicon and manganese content equal to ca. 0.6% and ca. 0.04%, respectively, has been examined.It has been found that the performed treatment leads to the change in the alloy matrix from the nearly almost pearlitic to the ferritic-pearlitic one accompanied by changes in the shape of graphite precipitates. Due to applying both of the mentioned substances in the above stated amounts the graphite precipitates in cast iron have taken the shape of nodular and vermicular ones, and no presence of flake graphite has been revealed. A quantitative analysis of the performed treatment i.e. determining the fractions of graphite precipitates of different shapes has been possible by means of a computer image analyser.

  6. Estimation of integrity of cast-iron cask against impact due to free drop test, (1)

    International Nuclear Information System (INIS)

    Ductile cast iron is examined to use for shipping and storage cask from a economic point of view. However, ductile cast iron is considered to be a brittle material in general. Therefore, it is very important to estimate the integrity of cast iron cask against brittle failure due to impact load at 9 m drop test and 1 m derop test on to pin. So, the F.E.M. analysis which takes nonlinearity of materials into account and the estimation against brittle failure by the method which is proposed in this report were carried out. From the analysis, it is made clear that critical flaw depth (the minimum depth to initiate the brittle failure) is 21.1 mm and 13.1 mm in the case of 9 m drop test and 1 m drop test on to pin respectively. These flaw depth can be detected by ultrasonic test. Then, the cask is assured against brittle failure due to impact load at 9 m drop test and 1 m drop test on to pin. (author)

  7. Auto-analysis system for graphite morphology of grey cast iron.

    Science.gov (United States)

    Jiang, Hong; Tan, Yiyong; Lei, Junfeng; Zeng, Libo; Zhang, Zelan; Hu, Jiming

    2003-01-01

    The current method to classify graphite morphology types of grey cast iron is based on traditional subjective observation, and it cannot be used for quantitative analysis. Since microstructures have a great effect on the mechanical properties of grey cast iron and different types have totally different characters, six types of grey cast iron are discussed and an image-processing software subsystem that performs the classification and quantitative analysis automatically based on a kind of composed feature vector and artificial neural network (ANN) is described. There are three kinds of texture features: fractal dimension, roughness and two-dimension autoregression, which are used as an extracted feature input vector of ANN classifier. Compared with using only one, the checkout correct precision increased greatly. On the other hand, to achieve the quantitative analysis and show the different types clearly, the region segmentation idea was applied to the system. The percentages of the regions with different type are reported correctly. Furthermore, this paper tentatively introduces a new empirical method to decide the number of ANN hidden nodes, which are usually considered as a difficulty in ANN structure decision. It was found that the optimum hidden node number of the experimental data was the same as that obtained using the new method.

  8. Effect of alloying elements on solidification of primary austenite in Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2011-04-01

    Full Text Available Within the research, determined were direction and intensity of alloying elements influence on solidification way (directional orvolumetric of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu. 50 cast shafts dia. 20 mm were analysed.Chemical composition of the alloy was as follows: 1.7 to 3.3 % C, 1.4 to 3.1 % Si, 2.8 to 9.9 % Ni, 0.4 to 7.7 % Mn, 0 to 4.6 % Cu, 0.14 to0.16 % P and 0.03 to 0.04 % S. The discriminant analysis revealed that carbon influences solidification of primary austenite dendrites most intensively. It clearly increases the tendency to volumetric solidification. Influence of the other elements is much weaker. This means that the solidification way of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu does not differ from that in an unalloyed cast iron.

  9. Laser powder surfacing of the Si-Mo spheroidal cast iron with nickel powder

    Directory of Open Access Journals (Sweden)

    A. Klimpel

    2006-04-01

    Full Text Available Purpose: Investigation results are presented of the effect of main parameters of laser powder surfacing of the Si-Mo spheroidal cast iron with the nickel based powder on quality and shape of padding welds and portion of the substrate material in the padding weld.Design/methodology/approach: It was shown basing on investigation of the process of laser powder surfacing with the nickel based powder onto the spheroidal cast iron substrate that it is feasible to make high quality padding welds in the relatively wide range of parameters.Findings: Investigation results presented in the paper were carried out to determine quality of padding welds applied by laser powder surfacing with the nickel based powder onto the alloy spheroidal cast iron and especially to determine the padding welds adhesion to the substrate.Practical implications: It is possible to control the portion of the substrate material in the padding weld with high accuracy in a wide range from even a few per cent, by the relevant setting of the line energy of the laser beam and the powder feed rate.Originality/value: The developed implant test makes the qualitative and quantitative assessment possible of the adhesion of the padding weld to the substrate, Table 5, Figs. 7 to 11. All padding welds made within the range of the optimum welding parameters demonstrated very good adhesion and the break, depending on the nickel padding weld thickness, occurred in the fusion area or by pulling part of the padding weld out.

  10. Effect of Titanium on the Mechanical Properties and Microstructure of Gray Cast Iron for Automotive Applications

    Science.gov (United States)

    Gelfi, M.; Gorini, D.; Pola, A.; La Vecchia, G. M.

    2016-07-01

    Lamellar gray cast iron, with a mainly pearlitic microstructure, is widely used in the automotive industry, mostly in the manufacturing of brake disks. This work analyzes in depth the effects of small variations of titanium content on the microstructure and mechanical properties of cast iron brake disks. For this purpose, eight different heats of EN-GJL-250 cast iron were selected, with a similar chemical composition but with different titanium contents, varying from 0.013 to 0.031%. The drops in mechanical strength and hardness values measured on the high-Ti samples were correlated to microstructural variations quantitatively observed by means of optical and scanning electron microscope. It was found that titanium combines to form titanium nitrides, suppressing the beneficial microstructural effects of nitrogen at solidification. Residual nitrogen, if present in sufficient quantity, promotes the nucleation of primary austenite from the liquid and the formation of a fine microstructure, with small eutectic cells and lower graphite content. Such a microstructure provides brake disks with better mechanical properties. The interpretation of results was further supported by thermal analysis and thermodynamic calculations.

  11. Investigation of Residual Stresses and Distortion in Welded Pipe-Flange Joint of Different Classes

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2012-10-01

    Full Text Available ABSTRACT: Pipe and flange joints are commonly used in petrochemical, nuclear and process industries. Commonly, welding is used to make these joints which produces residual stresses and distortions. These stresses have detrimental effects on the structural integrity and service performance of the welded pipe joints. The objective of this study is to investigate the residual stresses and distortions during Gas Metal Arc Welding of pipe of schedule 40, nominal diameter 200 mm with different ANSI flanges of class numbers 150, 300, 600, 900, 1500, and 2500. Welding parameters including: voltage, current and heat as inputs were selected based on the literature available. The behaviour of the flanges of different classes is also discussed. In addition, the finite element methodology presented, in this paper, can be helpful for developing welding procedures for a range of pipe flange welded joint sizes in order to control the residual stresses and deformations. This will lead to optimised performance during bolt up and operating conditions.ABSTRAK: Paip dan sambungan flan biasanya digunakan dalam industri petrokimia, nuklear dan proses. Kimpalan menghasilkan tegasan sisa dan herotan, yang memberikan kesan yang merbahaya ke atas integriti struktur dan prestasi servis sambungan kimpalan paip. Objektif kajian ini adalah untuk mengkaji tegasan sisa dan herotan ketika kimpalan arka logam gas paip berjadual 40, diameter nominal 200mm dengan flan ANSI yang berbeza kelas # 150, 300, 600, 900, 1500, dan 2500. Parameter kimpalan termasuklah; voltan, arus dan haba input yang dipilih berdasarkan literatur sediada. Kelakuan flan yang berbeza kelas telah dibincangkan. Kaedah elemen finit yang dibentangkan adalah berguna dalam membangunkan prosedur kimpalan bagi julat saiz kimpalan flan paip unutk mengawal tegasan sisa dan canggaan i.e. bagi mengoptimakan prestasi ketika bolt up dan sedang beroperasi.                                 

  12. CORROSION RESISTANCE OF PEARLITIC AND BAINITIC CAST IRON IN A SYNTHETIC SOLUTION OF CONDENSED GAS FROM COMBUSTION

    Directory of Open Access Journals (Sweden)

    Sandra Matos Cordeiro Costa

    2015-03-01

    Full Text Available The corrosion of engine components of the combustion chamber is usually related to the formation of acids such as sulfuric and nitric. These acids are generated by the condensation of combustion gases that usually occur in vehicle exhaust systems. However, with the development of new technologies to reduce emissions, condensation is also being promoted in vehicle combustion chambers. This fact is associated with high exhaust gas recirculation rates, known as EGR (English term for Exhaust Gas Recirculation. Consequently, corrosion problems in the engine components are increasing, especially in cylinder liners alloy manufactured using cast iron. In this study, the corrosion resistance of two cast iron alloys, one with a pearlitic microstructure and the other with a bainite microstructure in a solution simulating the composition of the condensate obtained from the combustion gases. It was found that the microstructure of the cast iron is an important factor affecting the corrosion behavior. The results showed that none of the two materials investigated is resistant to corrosion in the test medium, and the small difference observed between the behavior of the two cast iron was related to its microstructure, which are dependent on their chemical compositions. The cast iron with a pearlitic microstructure showed less formation of corrosion products than the bainitic cast iron. This result is related to the presence of steadite phase, highly stable and resistant to corrosion in pearlitic microstructure. This phase (steadite anchors the corrosion products formed on the surface and act as a partial barrier slowing the progress of the corrosion process, that was more pronounced in the bainitic cast iron.

  13. Progress of Non-Destructive Testing Technique on Cast Iron%铸铁设备无损检测技术进展

    Institute of Scientific and Technical Information of China (English)

    沈功田; 李丽菲; 王珊珊; 香勇

    2011-01-01

    铸铁部件目前在锅炉、压力容器、压力管道、汽车、拖拉机、机床和通用机械中仍得到大量使用,为了提高它们的检测效率和安全性能,对无损检测技术提出了新的需求.综述了国内外铸铁材料的无损检测技术、标准和仪器设备现状,发现目视检测、磁粉检测、渗透检测和射线检测是成熟的和普遍使用的无损检测方法,超声检测在球墨铸铁的球化率测定方面比较成熟,在缺陷的斜探头检测方面还有待于完善.国内外目前尚缺乏成熟的在用铸铁设备裂纹的快速检测方法和技术,声振检测技术、声一超声检测技术和超声导波技术有解决这一技术难题的潜力,但需要深入进行研究.%Cast iron components are widely used in boilers, pressure vessels, pressure piping, automobile,tractor, machine tool and general machinery. In order to advance the testing efficiency and safety capability for them, some new non-destructive testing techniques are required in China. The NDT techniques, standards and instruments in the world are reviewed in this paper. It was found that visual testing, magnetic particle testing, dye penetration testing and radiographic testing methods were mature and widely used. Ultrasonic testing method is mature for the testing of the nodulizing ratio of nodular cast iron. It needs to be consummated for the testing of defects by use of angle beam. There are not mature quick testing techniques and methods for the cracks of in-service cast iron components. The sound vibration testing technique, sound-ultrasonic testing technique and ultrasonic guided wave testing technique possess the potential capability for this problem. But a lot of studies need to be performed.

  14. Uniaxial Fatigue of HDPE-100 Pipe. Experimental Analysis

    OpenAIRE

    Djebli, A.; A. Aid; M. Bendouba; Talha, A.; Benseddiq, N.; M. Benguediab; S. Zengah

    2014-01-01

    In this paper, an experimental analysis for determining the fatigue strength of PE-100, one of the most used High Density Polyethylene (HDPE) materials for pipes, under cyclic axial loadings is presented. HDPE is a thermoplastic material used for piping systems, such as natural gas distribution systems, sewer systems and cold water systems, which provides a good alternative to metals such as cast iron or carbon steel. One of the causes for failures of HDPE pipes is fatigue which is the result...

  15. Influence of a matrix on properties of mottled cast iron applied for mill rolls

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2010-07-01

    Full Text Available Mill rolls are ones of the most expensive tools applied in plastic working processes and have to satisfy several criteria, which allow them to be used. Cast iron mill rolls, due to their fracture toughness and tribological properties, are the most often applied at hot-rolling in the last rolling stands. This results from the smallest dynamic loads of such rolling stands and the decisive influence of the surface quality of these tools on the surface quality of the rolled product. An improper microstructure of rolls can lead to their premature wearing, e.g. broken flanges, pivots twisting off etc. By means of the heat treatment the matrix microstructure and morphology of carbide precipitationscan be modified and this in-turn can influence cast iron properties.Determination of the influence of microstructure changes, caused by the heat treatment, on the properties of EN-GJN-HV300 low-alloycast iron, after its modification and spheroidization – is the aim of the present paper. Those changes are based on the formation pearlitic or bainitic matrices at the similar morphology of graphite and ledeburitic cementite precipitations. The performed investigations should enable designing the heat treatment of cast iron metallurgical rolls in such a way as to obtain the optimal microstructures for functional parameters of these type of tools. The influence of changing the pearlitic matrix into the bainitic one on such properties as: hardness, impact strength, tensile strength, creep limit, bending strength and a stress intensity factor KIc was investigated in this study. Samples for testing, the listed above mechanical properties, were taken from an industrial casting with care to have pieces of very similar crystallization conditions.

  16. Fatigue strength of nodular cast iron with regard to heavy-wall applications

    Energy Technology Data Exchange (ETDEWEB)

    Bleicher, Christoph; Wagener, Rainer; Kaufmann, Heinz [Fraunhofer-Institut fuer Betriebsfestigkeit und Systemzuverlaessigkeit LBF, Darmstadt (Germany); Melz, Tobias [Fraunhofer-Institut fuer Betriebsfestigkeit und Systemzuverlaessigkeit LBF, Darmstadt (Germany); TU Darmstadt (Germany). Faculty of Mechanical Engineering

    2015-11-01

    For a proper estimation of the fatigue life of a heavy-walled cast component made of nodular cast iron, sufficient knowledge regarding the cyclic properties of the material is necessary. Based on the material parameters at hand for component design, different fatigue analysis procedures can be used. Elastic and elastic-plastic approaches can be adopted, with the latter being reserved only for local approaches. The present publication summarizes the cyclic material parameters gained during a research project by extensive material tests under stress and strain controlled cyclic loading at different load ratios for three nodular cast iron grades. In addition to an improved knowledge of the cyclic material behavior, the notch, the size effects and the mean stress sensitivity were of special concern during the investigations in order to provide an entire overview of the tested materials and thus input information for both stress and strain based design approaches. Tests were performed for specimens taken from large cast blocks of the nodular cast iron grades EN-GJS-400-18U-LT and EN-GJS-450-18, both with ferritic matrices, and EN-GJS-700-2 with a pearlitic matrix. For some of these materials, mean stress sensitivities above 0.5 were obtained during the investigations. These values are not covered by the common standards, which calculate lower values for the mean stress sensitivity. Cyclic material parameters for stress and strain controlled tests are given in this paper as well as values for the size effect, based on the concept of the highly stressed volume. The effect of different specimen sizes could be shown not only by stress but also by strain controlled tests.

  17. Effect of Microstructure on Impact Fatigue Resistance and Impact Wear Resistance of Medium Cr-Si Cast Iron

    Institute of Scientific and Technical Information of China (English)

    LI Wei

    2007-01-01

    A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron (Cr of 15 %) is not high sometimes, but its cost is not low. Thus, medium Cr-Si wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ball-on-ball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of medium Cr-Si cast iron are superior to those of martensitic high chromium cast iron (Cr of 15%). The main reasons are that (1) the stress in medium Cr-Si cast iron is released in the as-cast state; (2)the matrix is fine pearlite with better toughness and plasticity; (3) the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; (4) high silicon content improves the morphology of eutectic carbide; (5) there is no secondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear.

  18. Analysis of Graphite Morphology of Gray Cast Iron in Pulse Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    LI Qiu-shu; LIU Li-qiang; ZHAI Qi-jie

    2005-01-01

    By self-made pulse electrical source and strong magnetic field solidification tester,the effect of strong pulse magnetic field on graphite morphology and solidification structure of gray cast iron was studied.The results show that the structure is remarkably refined after treated by pulse magnetic field,and the width of graphite flakes is decreased while the length is increased after a slight decrease.The solidification temperature and eutectic temperature are increased and the undercooling degree of eutectic transformation is decreased by magnetic field.

  19. Valence electron structure of cast iron and graphltization behaviour criterion of elements

    Institute of Scientific and Technical Information of China (English)

    刘志林; 李志林; 孙振国; 杨晓平; 陈敏

    1995-01-01

    The valence electron structure of common alloy elements in phases of cast iron is calculated- The relationship between the electron structure of alloy elements and equilibrium, non-equilibrium solidification and graphitization is revealed by defining the bond energy of the strongest bond in a phase as structure formation factor S. A criterion of graphitization behaviour of elements is advanced with the critical value of the structure formation factor of graphite and the n of the strongest covalent bond in cementite. It is found that this theory conforms to practice very well when the criterion is applied to the common alloy elements.

  20. Influence of electromagnetic field parameters on the morphology of graphite in grey cast iron

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2009-01-01

    Full Text Available One way to improve the unification of the casting structure may be the application of forced convection of liquid metal during thecrystallization in the form or continuous casting mould. This paper presents the results describing the influence of selected parameters of rotating electromagnetic field enforcing the movement of liquid metal in the form on the morphology of graphite in grey cast iron. The results were fragmented graphite flakes in conditions of regulating the rate of cooling in the range of temperature TZAL

  1. Three-dimensional local residual stress and orientation gradients near graphite nodules in ductile cast iron

    DEFF Research Database (Denmark)

    Zhang, Yubin; Andriollo, Tito; Fæster, Søren;

    2016-01-01

    A synchrotron technique, differential aperture X-ray microscopy (DAXM), has been applied to characterize the microstructure and analyze the local mesoscale residual elastic strain fields around graphite nodules embedded in ferrite matrix grains in ductile cast iron. Compressive residual elastic...... strains are measured with a maximum strain of ∼6.5–8 × 10−4 near the graphite nodules extending into the matrix about 20 μm, where the elastic strain is near zero. The experimental data are compared with a strain gradient calculated by a finite element model, and good accord has been found...

  2. Study on Cracking Tendency and Mechanism of Gray Cast Iron Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    YE Hong; YAN Zhong-lin; HUANG Qi; YANG Hui

    2004-01-01

    In this paper, NiCrSiB and CoWC35 powder has been used in laser cladding of gray cast iron. The cracking tendency has also been discussed. The cracks have been observed with a scan electron microscopy to analyze the cracking mechanism. The results show that cracks have not appeared in NiCrSiB cladding. Nevertheless, the cracking tendency of CoWC35 cladding is extremely high and there are both cold cracks and hot cracks in the cladding. The cracking tendency of laser cladding depends on physical properties of the cladding material and plasticity and roughness of the cladding.

  3. Study on Cracking Tendency and Mechanism of Gray Cast Iron Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    YEHong; YANZhong-lin; HUANGQi; YANGHui

    2004-01-01

    In this paper, NiCrSiB and COWC35 powder has been used in laser cladding of gray cast iron. The cracking tendency has also been discussed. The cracks have been observed with a scan electron microscopy to analyze the cracking mechanism. The results show that cracks have not appeared in NiCrSiB cladding. Nevertheless, the cracking tendency of CoWC35 cladding is extremely high and there are both cold cracks and hot cracks in the cladding. The cracking tendency of laser cladding depends on physical properties of the cladding material and plasticity and roughness of the cladding.

  4. Graphite nodule count and size distribution in thin-walled ductile cast iron

    OpenAIRE

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    Graphite nodule count and size distribution have been analysed in thin walled ductile cast iron. The 2D nodule counts have been converted into 3D nodule count by using Finite Difference Method (FDM). Particles having a diameter smaller than 5 µm should be neglected in the nodule count as these are inclusions and micro porosities that do not influence the solidification morphology. If there are many small graphite nodules as in thin walled castings only 3D nodule count calculated by FDM will g...

  5. Effect of potassium on as-cast microstructure of a hypereutectic high chromium cast iron

    OpenAIRE

    Liu Qing; Yang Hua; Ding Haimin

    2011-01-01

    The present work mainly evaluates the effect of potassium (K) on as-cast microstructure of a hypereutectic high chromium cast iron by means of a field emission scanning electron microscope (FESEM) and an X-ray diffractometer using CuKα radiation with a 2θ range of 30-130°. Results showed that, with the addition of K-containing modifier, the large lath-like and/or rod-like primary M7C3 carbides can be modified to the hexagonal prisms, and the eutectic carbides can also be refined. In addition,...

  6. Properties of Cross-Rolled Low Alloy White Cast Iron Grinding Ball

    Institute of Scientific and Technical Information of China (English)

    CHANG Li-min; LIU Lin; LIU Jian-hua

    2007-01-01

    The low-energy, multi-impact fracture resistance and the abrasiveness of the cross-rolled low alloy white cast iron grinding balls were studied after heat treatments at residual rolling temperature. Moreover, the means by which they are damaged and characters of the wear surface were analyzed. The results show that high resistance to impact fracture and high abrasiveness can be achieved after appropriate heat treatment at residual rolling temperature. This kind of heat treatment technology has several advantages under low impact and hard abrasive. These results are very useful for determining the optimized heat treatment technology at residual rolling temperatures.

  7. Effect of graphite degradation on the LCF properties of nodular cast iron

    Directory of Open Access Journals (Sweden)

    Denk Josef

    2014-06-01

    Full Text Available The effect of degraded microstructure on the tensile and LCF properties was studied on a casing of a turbocharger, which exhibited locally irregular graphite formation. The tensile tests showed that the ductility values of the zone with degraded graphite decreased strongly compared to the zone with normal graphite, while the strength values decreased only slightly. Based on these results and a LCF reference curve for nodular cast iron with normal graphite structure, a synthetic LCF curve was generated for the material condition with degraded graphite structure. LCF tests on specimens with irregular graphite structure confirmed the predicted LCF behaviour quite good.

  8. FASHION THE KITCHEN: CAST IRON STOVES THE PROVINCE OF QUEBEC, 1900-1914

    Directory of Open Access Journals (Sweden)

    Lisa Baillargeon

    2010-01-01

    Full Text Available The role of aesthetics in the marketing strategies of Quebec’s foundries and retailers at the beginning of the 20th century is not well known. This qualitative analysis of published cast iron stove advertisements suggests that the use of aesthetics to market stoves was far more elaborate than the simple alignment with trendy or classic style categories. In fact, aesthetics were the cornerstone of advertising activities aimed at developing and capitalizing on various market segments at a time of burgeoning consumerism.

  9. Effect of silicon content and defects on the lifetime of ductile cast iron

    Directory of Open Access Journals (Sweden)

    Alhussein Akram

    2014-06-01

    Full Text Available In this work, the influence of microstructure on the mechanical properties has been studied for different grades of ferritic ductile cast iron. Mechanical tests were carried out and the effect of silicon on the resistance of material was well noticed. An increasing silicon content increases the strength and decreases the ductility of material. The lifetime and endurance limit of material were affected by the presence of defects in material and microstructure heterogeneity. Metallurgical characterizations showed that the silicon was highly segregated around graphite nodules which leads to the initiation of cracks. The presence of defects causes the stress concentration and leads to the initiation and propagation of cracks.

  10. Optimization of casting defects analysis with supply chain in cast iron foundry process

    Directory of Open Access Journals (Sweden)

    C. Narayanaswamy

    2016-10-01

    Full Text Available Some of the foundries are in need of meeting production targets and due to the urgency they ignore the rejections. The objective of this paper is to analyze the various defects, [1] from molding process in a cast iron foundry. The Failure Mode Effects Analysis (FMEA in quality control [2-6] with suitable supply chain for mold making process considering rejection rates are identified and analyzed in terms of Risk Priority Number (RPN to prioritize the attention for each of the problem. The optimum levels of selected parameters [7] are obtained in this analysis.

  11. Investigation of solidification of thin walled ductile cast iron using temperature measurement

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels

    2005-01-01

    Investigation of solidification of thin walled ductile cast iron can be improved using temperature measurement. This article includes some background of the precautions that have to be taken when measuring temperatures in thin walled castings. The aim is to minimize influence of temperature...... measurement on castings and to get sufficient response time of thermocouples. Investigation of thin wall ductile iron has been performed with temperature measurement in plates with thickness between 2,8 and 8mm. The cooling curves achieved are combined with examination of the microstructure in order to reveal...

  12. Undercooling, nodule count and carbides in thin walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    Ductile cast iron has been cast in plate thicknesses between 2 to 8 mm. The temperature has been measured during the solidification and the graphite nodule count and size distribution together with the type and amount of carbides have been analysed afterwards. Low nodule count gives higher...... undercooling and primary carbides will then be formed in the first part of the solidification. Inverse chill carbides are formed at the final part of the solidification if the undercooling is too high at that point. A high number of graphite nodules nucleated in the last part of the solidification process...

  13. Microstructure and wear resistance of high chromium cast iron containing niobium

    OpenAIRE

    Zhang Zhiguo; Yang Chengkai; Zhang Peng

    2014-01-01

    In the paper, the effect of niobium addition on the microstructure, mechanical properties and wear resistance of high chromium cast iron has been studied. The results show that the microstructure of the heat-treated alloys is composed of M7C3 and M23C6 types primary carbide, eutectic carbide, secondary carbide and a matrix of martensite and retained austenite. NbC particles appear both inside and on the edge of the primary carbides. The hardness of the studied alloys maintains around 66 HRC, ...

  14. A Methodology to Predict Uniform Material Fatigue Life of Cast Iron: Law for Cast Iron%A Methodology to Predict Uniform Material Fatigue Life of Cast Iron: Law for Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Sinan Korkmaz

    2011-01-01

    Mechanical, physical and manufacturing properties of east iron make it attractive for many fields of application, such as cranks and cylinder holds. As in design of all metals, fatigue life prediction is an intrinsic part of the design process of structural sections that are made of cast iron. A methodology to predict high-cycle fatigue life of cast iron is proposed. Stress amplitude-strain amplitude, strain amplitude-number of loading cycles relationships of cast iron are investigated. Also, fatigue life prediction in terms of Smith, Watson and Topper parameter is carried out using the proposed method. Results indicate that the analytical outcomes of the proposed methodology are in good accordance with the experimental data for the two studied types of cast iron: EN-GJS-400 and EN-GJS-600.

  15. Effect of titanium on the as-cast microstructure and impact toughness of hypereutectic high-chromium cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhifu; Xing, Jiandong; Gao, Yimin; Zhi, Xiaohui [Xi' an Jiaotong Univ., Xi' an (China). State Key Lab. for Mechanical Behavior of Materials

    2012-05-15

    The effect of titanium on the as-cast microstructure of a hypereutectic high-chromium cast iron was investigated by means of optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicate that the primary M{sub 7}C{sub 3} carbides are refined and spheroidized with the addition of a suitable amount of titanium. TiC is found in the primary carbide by energy dispersive spectroscopy analysis. The mechanism of titanium modification on the microstructure of the alloy is also discussed. In addition, the impact test result indicates that, compared with the hypereutectic high-chromium cast iron without titanium addition, the impact toughness value of hypereutectic high-chromium cast iron with titanium additions is improved and approximately reaches 6.4 J . cm{sup -2}. (orig.)

  16. Effect of Rare Earth Alloy Modification on High Carbon Equivalent Gray Cast Iron of Automotive Brake Drum

    Institute of Scientific and Technical Information of China (English)

    ZHANG Daowen; LI Zhu; HUANG Jie

    2012-01-01

    Effect of rare earth alloy modification on properties and microstructure of high carbon equivalent gray cast iron was investigated.The experimental results show that in the way of mechanical property,when the addition of rare earth alloy is 0.2% and 0.3%,the tensile strength of cast iron increases.In the way of microstructure,the addition of rare earth alloy increases the number of primary austenite dendrites,reduces secondary dendritic arm spacing,and changes the eutectic size and quantity.When rare earth alloy is added into gray cast iron,the morphology and quantity of graphite play a major role on the improvement of tensile strength.

  17. High-Cycle Fatigue Resistance of Si-Mo Ductile Cast Iron as Affected by Temperature and Strain Rate

    Science.gov (United States)

    Matteis, Paolo; Scavino, Giorgio; Castello, Alessandro; Firrao, Donato

    2015-09-01

    Silicon-molybdenum ductile cast irons are used to fabricate exhaust manifolds of internal combustion engines of large series cars, where the maximum pointwise temperature at full engine load may be higher than 973 K (700 °C). In this application, high-temperature oxidation and thermo-mechanical fatigue (the latter being caused by the engine start and stop and by the variation of its power output) have been the subject of several studies and are well known, whereas little attention has been devoted to the high-cycle fatigue, arising from the engine vibration. Therefore, the mechanical behavior of Si-Mo cast iron is studied here by means of stress-life fatigue tests up to 10 million cycles, at temperatures gradually increasing up to 973 K (700 °C). The mechanical characterization is completed by tensile and compressive tests and ensuing fractographic examinations; the mechanical test results are correlated with the cast iron microstructure and heat treatment.

  18. Effect of Bi on graphite morphology and mechanical properties of heavy section ductile cast iron

    Directory of Open Access Journals (Sweden)

    Song Liang

    2014-03-01

    Full Text Available To improve the mechanical properties of heavy section ductile cast iron, bismuth (Bi was introduced into the iron. Five castings with different Bi content from 0 to 0.014 wt.% were prepared; and four positions in the casting from the edge to the center, with different solidification cooling rates, were chosen for microstructure observation and mechanical properties test. The effect of the Bi content on the graphite morphology and mechanical properties of heavy section ductile cast iron were investigated. Results show that the tensile strength, elongation and impact toughness at different positions in the five castings decrease with a decrease in cooling rate. With an increase in Bi content, the graphite morphology and the mechanical properties at the same position are improved, and the improvement of mechanical properties is obvious when the Bi content is no higher than 0.011wt.%. But when the Bi content is further increased to 0.014wt.%, the improvement of mechanical properties is not obvious due to the increase of chunky graphite number and the aggregation of chunky graphite. With an increase in Bi content, the tensile fracture mechanism is changed from brittle to mixture ductile-brittle fracture.

  19. Graphite nodule count and size distribution in thin-walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    Graphite nodule count and size distribution have been analysed in thin walled ductile cast iron. The 2D nodule counts have been converted into 3D nodule count by using Finite Difference Method (FDM). Particles having a diameter smaller than 5 µm should be neglected in the nodule count as these ar......Graphite nodule count and size distribution have been analysed in thin walled ductile cast iron. The 2D nodule counts have been converted into 3D nodule count by using Finite Difference Method (FDM). Particles having a diameter smaller than 5 µm should be neglected in the nodule count...... as these are inclusions and micro porosities that do not influence the solidification morphology. If there are many small graphite nodules as in thin walled castings only 3D nodule count calculated by FDM will give reliable results. 2D nodule count and 3D nodule count calculated by simple equations will give too low...... results. The 3D size distribution showed presence of primary graphite nodules in hypereutectic castings. In thin plates the nodule count is similar in eutectic and hypereutectic plates. In thicker plates the hypereutectic casting has the highest nodule count....

  20. Strength distribution at interface of rotary-friction-welded aluminum to nodular cast iron

    Institute of Scientific and Technical Information of China (English)

    SONG Yu-lai; LIU Yao-hui; ZHU Xian-yong; YU Si-rong; ZHANG Ying-bo

    2008-01-01

    The morphology, size and composition of intermetallic compound at the interface of Al 1050 and nodular cast iron were studied by electron microprobe analysis(EMPA) and scan electron microscopy (SEM), respectively. The bond strength of the interface was measured by the tensile tests and the morphology of the fracture surface was observed by SEM. The observation of the interface reveals that there are two distinct morphologies: no intermetallic compound exists in the central area at the interface; while numbers of intermetallic compounds (FexAly) are formed in the peripheral area due to the overfull heat input. The tensile tests indicate that the distribution of strength in radial direction at the interface is inhomogeneous, and the central area of the interface performs greater bond strength than the peripheral area, which proves directly that the FexAly intermetallic compounds have a negative effect on the integration of interface. The morphology on the fracture surface shows that the facture in the central area at the interface has characteristic of the ductile micro-void facture. So it is important to restrain the form of the intermetallic compound to increase the bond strength of the Al 1050 and nodular cast iron by optimizing welding parameters and the geometry of components.

  1. Study of microstructure and silicon segregation in cast iron using color etching and electron microprobe analysis

    International Nuclear Information System (INIS)

    An investigation on silicon segregation of lamellar, compacted and nodular graphite iron was carried out by applying a selective, immersion color etching and a modified electron microprobe to study the microstructure. The color etched micrographs of the investigated cast irons by revealing the austenite phase have provided data about the chronology and mechanism of microstructure formation. Moreover, electron microprobe has provided two dimensional segregation maps of silicon. A good agreement was found between the segregation profile of silicon in the color etched microstructure and the silicon maps achieved by electron microprobe analysis. However, quantitative silicon investigation was found to be more accurate than color etching results to study the size of the eutectic colonies. - Highlights: • Sensitivity of a color etchant to silicon segregation is quantitatively demonstrated. • Si segregation measurement by EMPA approved the results achieved by color etching. • Color etched micrographs provided data about solidification mechanism in cast irons. • Austenite grain boundaries were identified by measuring the local Si concentration

  2. Study of microstructure and silicon segregation in cast iron using color etching and electron microprobe analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vazehrad, S., E-mail: vazehrad@kth.se [Dep. Materials Science and Engineering/Casting of Metals, Royal Institute of Technology, SE-100 44 Stockholm (Sweden); Elfsberg, J., E-mail: jessica.elfsberg@scania.com [Scania CV AB, SE-151 87 Södertälje (Sweden); Diószegi, A., E-mail: attila.dioszegi@jth.hj.se [Dep. Materials Science and Engineering/Casting of Metals, Royal Institute of Technology, SE-100 44 Stockholm (Sweden); Dep. Mechanical Engineering/Materials and Manufacturing-Foundry Technology, Jönköping University, SE-551 11 Jönköping (Sweden)

    2015-06-15

    An investigation on silicon segregation of lamellar, compacted and nodular graphite iron was carried out by applying a selective, immersion color etching and a modified electron microprobe to study the microstructure. The color etched micrographs of the investigated cast irons by revealing the austenite phase have provided data about the chronology and mechanism of microstructure formation. Moreover, electron microprobe has provided two dimensional segregation maps of silicon. A good agreement was found between the segregation profile of silicon in the color etched microstructure and the silicon maps achieved by electron microprobe analysis. However, quantitative silicon investigation was found to be more accurate than color etching results to study the size of the eutectic colonies. - Highlights: • Sensitivity of a color etchant to silicon segregation is quantitatively demonstrated. • Si segregation measurement by EMPA approved the results achieved by color etching. • Color etched micrographs provided data about solidification mechanism in cast irons. • Austenite grain boundaries were identified by measuring the local Si concentration.

  3. INFLUENCE OF ANNEALING ON HARDNESS OF Cr-Mn-Ni CAST IRONS

    Directory of Open Access Journals (Sweden)

    V. V. Netrebko

    2015-01-01

    Full Text Available The necessary level of material’s hardness is determined by the exploitation conditions and presence of technological operations during manufacturing of articles. Mechanical edge cutting machining of wear resistant materials is impeded because of their high hardness. It is recommended to apply annealing in order to decrease hardness and improve machinability. The purpose of the work consisted in obtaining of regression dependences of cast iron’s macrohardness on its chemical content after annealing at 730 °С. With the use of mathematical experimental design the regression dependences of cast iron’s macrohardness and structural components’ microhardness on С, Cr, Mn, Ni content have been established. The minimal hardness of 27,6 HRC after annealing at 730 °С is obtained in the cast iron containing: 3,9% С; 11,4% Cr; 0,6% Mn; 0,2% Ni. The maximal hardness of 70,4 HRC is obtained when the content is as follows: 1,1% С; 25,6% Cr; 5,4% Mn; 3,0% Ni. Annealing at 730 °С decreases the cast irons’ hardness containing the minimal amount of Cr, Mn and Ni. Annealing at 730 °С is recommended for cast irons alloyed by Mn and Ni for increasing of hardness.

  4. ELABORATION OF MANAGEMENT PLAN OF SOLID WASTE FROM SMALL CAST IRON FOUNDRIES

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Mendes Moraes

    2013-12-01

    Full Text Available The foundry industry contributes to society meeting the demand of metal scrap recycling, but, at the same time, it brings a high risk of environmental impact for its many potentially pollutant wastes. Among these, there are slag and used foundry sand (cold cure molding. Through a survey about the production process of a small cast iron company, the collected data was compiled to determine the organizational setting in terms of generation and segregation of waste. From a complete environmental diagnosis carried out in eight small cast iron foundries, one of them was chosen to be a basis for the elaboration of an industrial solid waste management plan, which is becoming necessary to know and manage the generation of wastes qualitatively and quantitatively. A data assessment about the production process was carried out and compiled to determine the actual organizational scenario. As a result of that, it is possible to create a favorable environment to develop tools for environmental impacts prevention, which will permit the migration for more complex actions on the direction of more efficient process, cleaner production, and internal and external recycling of exceeding materials.

  5. Nucleation and Growth of Graphite in Eutectic Spheroidal Cast Iron: Modeling and Testing

    Science.gov (United States)

    Carazo, Fernando D.; Dardati, Patricia M.; Celentano, Diego J.; Godoy, Luis A.

    2016-06-01

    A new model of graphite growth during the continuous cooling of eutectic spheroidal cast iron is presented in this paper. The model considers the nucleation and growth of graphite from pouring to room temperature. The microstructural model of solidification accounts for the eutectic as divorced and graphite growth rate as a function of carbon gradient at the liquid in contact with the graphite. In the solid state, the microstructural model takes into account three stages for graphite growth, namely (1) from the end of solidification to the upper bound of intercritical stable eutectoid, (2) during the intercritical stable eutectoid, and (3) from the lower bound of intercritical stable eutectoid to room temperature. The micro- and macrostructural models are coupled using a sequential multiscale approach. Numerical results for graphite fraction and size distribution are compared with experimental results obtained from a cylindrical cup, in which the graphite volumetric fraction and size distribution were obtained using the Schwartz-Saltykov approach. The agreements between the experimental and numerical results for the fraction of graphite and the size distribution of spheroids reveal the importance of numerical models in the prediction of the main aspects of graphite in spheroidal cast iron.

  6. The structure and mechanical properties of pearlitic-ferritic vermicular cast iron

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2012-01-01

    Full Text Available The results of studies on the use of magnesium alloy in modern Tundish + Cored Wire injection method for production of vermicular graphite cast irons were described. The injection of Mg Cored Wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire for the production of vermicular graphite cast irons at the; Tundish + Cored Wire to be injected methods (PE for pearlitic-ferritic matrix GJV with about 25 %ferrite content. The results of calculations and experiments have indicated the length of the Cored Wire to be injected basing on the initial sulfur content and weight of the treated melt. The paper presents a microstructure matrix and vermicular graphite in standard sample and different walled castings. The results of numerous trials have shown that the magnesium Tundish + PE Method process can produce high quality vermicular graphite irons under the specific industrial conditions of the above mentioned foundries.

  7. Graphite Nucleation in Cast Iron Melts Based on Solidification Experiments and Microstructure Simulation

    Institute of Scientific and Technical Information of China (English)

    Andreia Sommerfeld; Bernd B(o)ttger; Babette Tonn

    2008-01-01

    Microstructure strongly influences the mechanical properties of cast iron. By inoculating the melt with proper inoculants, foreign substrates are brought into the melt and eventually the graphite can crystallize on them. The elements and substrates that really play a role for nucleation are yet unknown. Until now there is very little knowledge about the fundamentals of nucleation, such as composition and morphology of nuclei[1,2]. In this work we utilized EN-GJL-200 as a base material and examined several produced specimens. The specimens were cast with and without inoculants and quenched at different solidification states. Specimens were also examined with a high and low oxygen concentration, but the results showed that different oxygen contents have no influence on the nucleation in cast iron melts. Our research was focused on the microscopic examination and phase-field simulations. For studying the samples we applied different analytical methods, where SEM-EDS, -WDS were proved to be most effective. The simulations were conducted by using the software MICRESS(R)[3], which is based on a multiphase-field model and has been coupled directly to the TCFE3 thermodynamic database from TCAB. On the basis of the experimental investigations a nucleation mechanism is proposed, which claims MnS precipitates as the preferred site for graphite nucleation. This theory is supported by the results of the phase-field simulations.

  8. Mechanism of carbon influence on the transition from graphite to cementite eutectic in cast iron

    Directory of Open Access Journals (Sweden)

    E. Fraś

    2010-04-01

    Full Text Available In this work an analytical solution is used to explain mechanism of carbon influence on the transition from graphite to cementite eutectic in cast iron. It is found that this transition can be related to (1 the nucleation potential of graphite (characterized directly by the cell count, N and indirectly by nucleation coefficients Ns and b (2 the growth rate coefficient of graphite eutectic cell, (3 the temperature range, Tsc = Ts - Tc (where Ts and Tc is the equilibrium temperature of the graphite eutectic and formation temperature of the cementite eutectic respectively.and (4 the liquid volume fraction, fl after solidification of the pre-eutectic austenite. Method of estimation of Ns, b and values was presented. It has been shown that the main impact of carbon on the transition from graphite to cementite eutectic consist in increasing the eutectic cell count and growth rate of graphite eutectic cell. Analytical equations were derived to describe the absolute, CT relative chilling tendency, CTr and chill, w of cast iron.

  9. Effects of Rare Earths and Al on Structure and Performance of High Chromium Cast Iron Containing Wolfram

    Institute of Scientific and Technical Information of China (English)

    Guo Erjun; Wang Liping; Huang Yongchang; Fu Yuanke

    2006-01-01

    Effects of RE and Al on the structure, impact toughness, hardness, and wear resistance of high chromium cast iron containing wolfram were investigated.The results show that without modification the volume fraction of austenite is high and the carbide appears to be thick lath and the grain size is relatively large;proper modification using RE combined with Al can reduce volume fraction of residual austenite in the as-cast structure obviously, refine grain size of primary austenite notably, and make the morphology of carbide changing from thick lath to thin lath, rosette, and feather-like modification can also increase hardness, wear resistance and impact toughness of cast iron.

  10. Study on quantitative relation between characteristics of striature bionic coupling unit and wear resistance of gray cast iron

    Science.gov (United States)

    Pang, Zuobo; Zhou, Hong; Zhang, Peng; Cong, Dalong; Meng, Chao; Wang, Chuanwei; Ren, Luquan

    2015-03-01

    In order to improve the wear resistance of gray cast iron guide rail, striature bionic coupling units of different characteristics were manufactured by laser surface remelting. Wear behavior of gray cast iron with striature bionic coupling units has been studied under dry sliding condition at room temperature using a homemade linear reciprocating wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that there is a relationship between weight loss and the area of striature bionic coupling units and α: Δm = Δm0 - 0.0212S × cos α - 0.0241S × sin α.

  11. Effect of the microhardness difference between base metal and bionic coupling unit on wear resistance of gray cast iron

    Science.gov (United States)

    Pang, Zuobo; Zhou, Hong; Chang, Fang; Zhang, Peng; Cong, Dalong; Meng, Chao; Wang, Chuanwei; Ren, Luquan

    2015-12-01

    In order to improve the wear resistance of gray cast iron guide rail, the samples with different microhardness difference between bionic coupling units and base metal were manufactured by laser surface remelting. Wear behavior of gray cast iron with bionic coupling units has been studied under dry sliding condition at room temperature using a homemade liner reciprocating wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that when the microhardness difference is 561 HV0.2, the wear resistance of sample is the best.

  12. Joint layout, pipe size and hydraulic reliability optimization of water distribution systems

    Science.gov (United States)

    Tanyimboh, Tiku; Setiadi, Yohan

    2008-08-01

    A multicriteria maximum-entropy approach to the joint layout, pipe size and reliability optimization of water distribution systems is presented. The capital cost of the system is taken as the principal criterion, and so the trade-offs between cost, entropy, reliability and redundancy are examined sequentially in a large population of optimal solutions. The novelty of the method stems from the use of the maximum-entropy value as a preliminary filter, which screens out a large proportion of the candidate layouts at an early stage of the process before the designs and their reliability values are actually obtained. This technique, which is based on the notion that the entropy is potentially a robust hydraulic reliability measure, contributes greatly to the efficiency of the proposed method. The use of head-dependent modelling for simulating pipe failure conditions in the reliability calculations also complements the method in locating the Pareto-optimal front. The computational efficiency, robustness, accuracy and other advantages of the proposed method are demonstrated by application to a sample network.

  13. Corrosion Inhibiting Mechanism of Nitrite Ion on the Passivation of Carbon Steel and Ductile Cast Iron for Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    K. T. Kim

    2015-01-01

    Full Text Available While NaNO2 addition can greatly inhibit the corrosion of carbon steel and ductile cast iron, in order to improve the similar corrosion resistance, ca. 100 times more NaNO2 addition is needed for ductile cast iron compared to carbon steel. A corrosion and inhibition mechanism is proposed whereby NO2- ion is added to oxidize. The NO2- ion can be reduced to nitrogen compounds and these compounds may be absorbed on the surface of graphite. Therefore, since nitrite ion needs to oxidize the surface of matrix and needs to passivate the galvanic corroded area and since it is absorbed on the surface of graphite, a greater amount of corrosion inhibitor needs to be added to ductile cast iron compared to carbon steel. The passive film of carbon steel and ductile cast iron, formed by NaNO2 addition showed N-type semiconductive properties and its resistance, is increased; the passive current density is thus decreased and the corrosion rate is then lowered. In addition, the film is mainly composed of iron oxide due to the oxidation by NO2- ion; however, regardless of the alloys, nitrogen compounds (not nitrite were detected at the outermost surface but were not incorporated in the inner oxide.

  14. The identification of pouring conditions of cast iron to sand moulds

    Directory of Open Access Journals (Sweden)

    B. Borowiecki

    2008-04-01

    Full Text Available The structure and properties of the castings in cast iron put on spheroidization depend especially on the pouring conditions. Decisive factor of local castings properties can be the flow ability of liquid metal in sand mould, which depends not only on chemical constitutions but also on temperature and velocity of pouring. The parameter, which take into consideration various factors is a substitute rheological parameter θ proposed in early author’s papers [1, 2]. The parameter determined in fluidity test can be used to calculation of thickness of rheological boundary layer metal in gating system channel and in casting. The identification a thermal properties of sand mould material has been require of investigation proposed in literature [3, 4]. In the article presented also the experimental of measurement results of metal levels in piezometers located on the horizontal cross gate.

  15. Laser Surface Remelting of Medium Ni-Cr Infinite Chilling Cast Iron Roll

    Institute of Scientific and Technical Information of China (English)

    YAO Jian-hua; ZHANG Qun-li; XIE Song-jing

    2004-01-01

    Laser surface remelting of medium Ni-Cr infinite chilling cast iron was performed with a continuous wave CO2 laser beam with the power of 7 KW under the argon shielding. The microstructural analysis of the laser remelted layer by optical microscope shows that the laser remelted layer consists of three zones, which is the melting zone, the transition zone and the heat affected zone. The size of the dendrite of the melting zone is only in the 1/10 to 1/30 range of that of the substrate. The distribution of the hardness of the laser remelted layer was detected, and the carrying capacity of rolling steel was also field-tested. The results show that both the hardness of the remelted layer and the carrying capacity all increase,especially, the carrying capacity was 50% increased compared with the substrate.

  16. Laser Surface Remelting of Medium Ni-Cr Infinite Chilling Cast Iron Roll

    Institute of Scientific and Technical Information of China (English)

    YAOJian-hua; ZHANGQun-li; XIESong-jing

    2004-01-01

    Laser surface remelting of medium Ni-Cr infinite chilling cast iron was performed with a continuous wave CO2 laser beam with the power of 7 KW under the argon shielding. The microstructural analysis of the laser remelted layer by optical microscope shows that the laser remelted layer consists of three zones, which is the melting zone, the transition zone and the heat affected zone. The size of the dendrite of the melting zone is only in the 1/10 to 1/30 range of that of the substrate. The distribution of the hardness of the laser remelted layer was detected, and the carrying capacity of rolling steel was also field-tested. The results show that both the hardness of the remelted layer and the carrying capacity all increase, especially, the carrying capacity was 50% increased compared with the substrate.

  17. Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-10-01

    Full Text Available It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B4C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

  18. ANALYSIS OF FORCES, ROUGHNESS, WEAR AND TEMPERATURE IN TURNING CAST IRON USING CRYOTREATED CARBIDE INSERTS

    Directory of Open Access Journals (Sweden)

    B.R. Ramji,

    2010-07-01

    Full Text Available The aim of this research was to examine the effect of cryogenic treatment of the coated carbide inserts on their performance in turning gray cast iron work pieces. The cryogenic treatment cycle consisted of cooling the test samples from room temperature to cryogenic temperature of -178.9 C in three hours, soaking at cryogenictemperature around 24 hours and warming to room temperature in about five hours. Cutting forces, surface roughness, flank wear and tool tip temperature were studied for both coated and coated-treated inserts. ANOVA was performed to identify the effect of the parameters on the response variables. Cryogenically treated inserts proved superior to the non-treated in all the test conditions in terms of lesser flank wear of the inserts and reduced surface roughness of the specimens. The after turned inserts were examined using Scanning Electron Microscopy for studying the flank wear mechanism.

  19. Effect of Cu and Mn on the Mechanical Properties and Microstructure of Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    A.M.Omran

    2014-06-01

    Full Text Available This paper described the method used for producing ductile cast iron (SGI. The processing parameters affecting the production of SGI were studied. These parameters include chemical composition, castings thickness, mechanical properties, alloying elements and microstructure. The chemical composition of producing SGI was optimized. The nodularity was increased with increasing the percentages of Mg content and with decreasing the castings thickness. The amount of pearlite and mechanical properties were increased sharply with increasing Cu and Mn contents in the produced SGI. Empirical equations were correlated to indicate the relations among nodularity, Mg content and other parameters. The results shown also as the post inoculation increased the metallurgical quality was improved. The suitability of SGI as automotive engine was tested and different empirical correlations were obtained

  20. Effect of cerium modification on microstructure and properties of hypereutectic high chromium cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Zhi, Xiaohui, E-mail: mkmkzxh@hotmail.com [School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, Hebei Province (China); Liu, Jinzhi [School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, Hebei Province (China); Xing, Jiandong; Ma, Shengqiang [State Key Laboratory Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049, Shaanxi Province (China)

    2014-05-01

    The effect of cerium modification on the microstructure and properties of hypereutectic high chromium cast iron primarily containing 4.0 wt% C and 20.0 wt% Cr was studied by means of optical microscopy, transmission electron microscope, scanning electron microscope, and energy dispersive X-ray spectrometry. The primary M{sub 7}C{sub 3} carbides were refined obviously when cerium was added in the melt. Ce{sub 2}S{sub 3} was found in the primary M{sub 7}C{sub 3} carbides and acted as the heterogeneous substrate of M{sub 7}C{sub 3} carbides. The impact toughness of the specimen modified with 0.5 wt% cerium increased by 50% compared with the specimen without cerium modification. The hardness of the alloy modified with cerium increased slightly compared with the specimen without cerium modification.

  1. Thermal Microstructural Multiscale Simulation of Solidification and Eutectoid Transformation of Hypereutectic Gray Cast Iron

    Science.gov (United States)

    Urrutia, Alejandro; Celentano, Diego J.; Gunasegaram, Dayalan R.; Deeva, Natalia

    2014-08-01

    Although the gray cast iron solidification process has been the subject of several modeling studies, almost all available models appear to deal with only the more widely used hypoeutectic compositions. Models related to hypereutectic gray iron compositions with lamellar (or flake) graphite, and in particular for the proeutectic and eutectoid zones, are hard to find in the open literature. Hence, in the present work, a thermal microstructural multiscale model is proposed to describe the solidification and eutectoid transformation of a slightly hypereutectic composition leading to lamellar graphite gray iron morphology. The main predictions were: (a) temperature evolutions; (b) fractions of graphite, ferrite, and pearlite; (c) density; and (d) size of ferrite, pearlite, and gray eutectic grains; (e) average interlamellar graphite spacing; and (f) its thickness. The predicted cooling curves and fractions for castings with two different compositions and two different pouring temperatures were validated using experimental data. The differences between this model and existing models for hypoeutectic compositions are discussed.

  2. Effect of potassium on as-cast microstructure of a hypereutectic high chromium cast iron

    Directory of Open Access Journals (Sweden)

    Liu Qing

    2011-05-01

    Full Text Available The present work mainly evaluates the effect of potassium (K on as-cast microstructure of a hypereutectic high chromium cast iron by means of a field emission scanning electron microscope (FESEM and an X-ray diffractometer using CuKα radiation with a 2θ range of 30-130°. Results showed that, with the addition of K-containing modifier, the large lath-like and/or rod-like primary M7C3 carbides can be modified to the hexagonal prisms, and the eutectic carbides can also be refined. In addition, the carbides are distributed much more homogeneously in the matrix. The modification effect of K is due to its aggregation at the liquid-solid interface and the adsorption on the relatively fast growing planes during the solidification, which influence the growth rates of different crystal planes and lead to the modification of the carbides.

  3. Fatigue crack tip damaging micromechanisms in a ferritic-pearlitic ductile cast iron

    Directory of Open Access Journals (Sweden)

    Francesco Iacoviello

    2015-07-01

    Full Text Available Due to the peculiar graphite elements shape, obtained by means of a chemical composition control (mainly small addition of elements like Mg, Ca or Ce, Ductile Cast Irons (DCIs are able to offer the good castability of gray irons with the high mechanical properties of irons (first of all, toughness. This interesting properties combination can be improved both by means of the chemical composition control and by means of different heat treatments(e.g. annealing, normalizing, quenching, austempering etc. In this work, fatigue crack tip damaging micromechanisms in a ferritic-pearlitic DCI were investigated by means of scanning electron microscope observations performed on a lateral surface of Compact Type (CT specimens during the fatigue crack propagation test (step by step procedure, performed according to the “load shedding procedure”. On the basis of the experimental results, different fatigue damaging micromechanisms were identified, both in the graphite nodules and in the ferritic – pearlitic matrix.

  4. TECHNICAL CONDITION OF HIGH-STRENGTH CAST IRON CRANKSHAFTS FROM AND MATERIAL SELECTION FOR THEIR RESTORATION

    Directory of Open Access Journals (Sweden)

    T. Vigerina

    2013-01-01

    Full Text Available The paper presents data on a technical condition of cast iron crankshafts to be repaired which is characterized by wear of crankshaft necks and connecting rod journals and misalignment of crankshaft  necks of ZMZ-53-engines. Wear and misalignment of crankshaft necks are closely described by the the Weibull's law and 70–75 % of the shafts to be repaired require recovery with deposition of coating. In order to recover crankshaft necks it is proposed to apply plasma spraying with a mixture of powders which includes copper powder. Coating obtained in accordance with the proposed technology is characterized by wear intensity during its normal operation 4,0 · 10–6 g/m, and it is by 3–5 % lower than the wear intensity rate of those shafts that have been recovered with the help of spraying powder mixtures without copper.

  5. Correlation of mechanical properties with the acoustic properties in case of an experimental white cast iron

    Science.gov (United States)

    Gȋrneţ, A.; Stanciu, S.; Chicet, D.; Axinte, M.; Goanţă, V.

    2016-08-01

    The general and traditional opinion regarding the materials used to build bells, musical instruments or sound transmitters is that those materials must be only from the bronze alloyed with tin category. In order to approach this idea from a scientific point of view, the materials with acoustic properties must be analyzed starting from the physical theory and experimental determination that sound travels only through bodies with elastic properties. It has been developed an experimental white cast iron, medium alloyed with Cr and Ni, in order to obtain a material with special acoustic properties. There were determined on specific samples: the vibration damping capacity, the unit energy, the tensile strength and elasticity modulus. These properties were correlated with the properties of other known acoustic materials.

  6. SPHERICAL MICROSTRUCTURE FORMATION OF THE SEMI-SOLID HIGH CHROMIUM CAST IRON Cr20Mo2

    Institute of Scientific and Technical Information of China (English)

    W.M. Mao; A.M. Zhao; X.Y. Zhong

    2004-01-01

    The nondendritic semi-solid slurry preparation of high chromium cast iron Cr20Mo2 has been studied in this paper. The experiments show that the proeutectic austenitic particles are more spherical under a larger stirring power condition, even if the stirring time is shorter, while the proeutectic austenitic particles are not very much spherical under a smaller stirring power condition and some proeutectic austenitic dendrites also exist, even if the stirring time is very long. The experiments also show that when stirred for 5 6 minutes under the test condition, the semi-solid slurry with 40vol. %-50vol. % solid fraction and spherical proeutectic austenite in the size of 50-80μm can be obtained.

  7. Influences of single laser tracks' space on the rolling fatigue contact of gray cast iron

    Science.gov (United States)

    Chen, Zhi-kai; Zhou, Ti; Zhang, Peng; Zhang, Hai-feng; Yang, Wan-shi; Zhou, Hong; Ren, Lu-quan

    2015-09-01

    To improve the fatigue wear resistance of gray cast iron, the surface is modified by Nd:YAG laser to imitate the unique surface of soil creatures (alternative soft and hard phases). After laser treatment, the remelting region is the named unit which is mainly characterized of compact and refinement grains. In the present work, the influence of the unit space on the fatigue wear resistance is experimentally studied. The optimum space is proven to be 2 mm according to the tested results and two kinds of delamination are observed on samples' worn surface. Subsequently, the mechanisms of fatigue wear resistance improvement are suggested: (i) for microscopic behavior, the bionic unit not only delays the initiation of microcracks, but also significantly obstructs the propagation of cracks; (ii) for macroscopic behavior, the hard phase resists the deformation and the soft phase releases the deformation.

  8. Microstructure and wear resistance of high chromium cast iron containing niobium

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhiguo; Yang Chengkai; Zhang Peng; Li Wei

    2014-01-01

    In the paper, the effect of niobium addition on the microstructure, mechanical properties and wear resistance of high chromium cast iron has been studied. The results show that the microstructure of the heat-treated aloys is composed of M7C3 and M23C6 types primary carbide, eutectic carbide, secondary carbide and a matrix of martensite and retained austenite. NbC particles appear both inside and on the edge of the primary carbides. The hardness of the studied alloys maintains around 66 HRC, not significantly affected by the Nb content within the selected range of 0.48%-0.74%. The impact toughness of the aloys increases with increasing niobium content. The wear resistance of the specimens presents little variation in spite of the increase of Nb content under a light load of 40 N. However, when heavier loads of 70 and 100 N are applied, the wear resistance increases with increasing Nb content.

  9. Microstructure and wear resistance of high chromium cast iron containing niobium

    Directory of Open Access Journals (Sweden)

    Zhang Zhiguo

    2014-05-01

    Full Text Available In the paper, the effect of niobium addition on the microstructure, mechanical properties and wear resistance of high chromium cast iron has been studied. The results show that the microstructure of the heat-treated alloys is composed of M7C3 and M23C6 types primary carbide, eutectic carbide, secondary carbide and a matrix of martensite and retained austenite. NbC particles appear both inside and on the edge of the primary carbides. The hardness of the studied alloys maintains around 66 HRC, not significantly affected by the Nb content within the selected range of 0.48%-0.74%. The impact toughness of the alloys increases with increasing niobium content. The wear resistance of the specimens presents little variation in spite of the increase of Nb content under a light load of 40 N. However, when heavier loads of 70 and 100 N are applied, the wear resistance increases with increasing Nb content.

  10. Numerical modelling of solidification of thin walled hypereutectic ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Hattel, Jesper; Tiedje, Niels

    2006-01-01

    Numerical simulation of solidification of ductile cast iron is normally based on a model where graphite nodules are surrounded by an austenite shell. The two phases are then growing as two concentric spheres governed by diffusion of carbon through the austenite shell. Experiments have however shown...... simulation of thin-walled ductile iron castings. Simulations have been performed with a 1-D numerical solidi¬fication model that includes the precipitation of non-eutectic austenite during the eutectic stage. Results from the simulations have been compared with experimental castings with wall thick...... solidification had only one main stage. The simulations reveal that the first stage of solidification can be explained by precipitation of off-eutectic austenite...

  11. Residual stress distribution measurement in welded thick-walled pipe joints using inherent strain method. Comparison in different groove geometries

    International Nuclear Information System (INIS)

    The inherent strain method measures weld residual stress by coupling of approach to measure inherent strain which is source of residual stress in weld structures with elastic computation to estimate residual stress from inherent strain. In this study, the weld residual stress distributions in the welded thick-walled pipe joints of stainless steel were measured using the inherent strain method. The different features between residual stress distribution in the two kinds of joint with the standard and narrow groove geometries were clarified using the contour map of the whole joints estimated by the method. (author)

  12. A Journey across Multidirectional Connections: Linda Grant’s The Cast Iron Shore

    Directory of Open Access Journals (Sweden)

    Silvia Pellicer-Ortín

    2015-10-01

    Full Text Available Among the numerous groups that have negotiated their fragmented identities through various literary practices in the last few decades, the Jewish collective has come to symbolize the epitome of diaspora and homelessness. In particular, British-Jewish writers have recently started to reconstruct their fragmented memories through writing. This is an extremely interesting phenomenon in the case of those Jewish women who are fiercely struggling to find some sense of personhood as Jewish, British, female, immigrant subjects. Linda Grant’s novel The Cast Iron Shore will be analyzed so as to unveil the narrative mechanisms through which many of the identity tensions experienced by contemporary Jewish women are exhibited. The different stages in the main character’s journey will be examined by drawing on theories on the construction of Jewish identity and femininity, and by applying the model of multidirectional memory fostered by various contemporary thinkers such as Michael Rothberg, Stef Craps, Max Silverman, and Bryan Cheyette. The main claim to be demonstrated is that this narration links the (histories of oppression and racism endured both by the Jewish and the Black communities in order to make the protagonist encounter the Other, develop her mature political self, and liberate her mind from rigid religious, patriarchal, and racial stereotypes. The Cast Iron Shore becomes, then, a successful attempt to demonstrate that the (histories of displacement endured by divergent communities during the twentieth century are connected, and it is the establishment of these connections that can help contemporary Jewish subjects to claim new notions of their personhood in the public sphere.

  13. High-temperature low cycle fatigue behavior of a gray cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Fan, K.L., E-mail: 12klfan@tongji.edu.cn; He, G.Q.; She, M.; Liu, X.S.; Lu, Q.; Yang, Y.; Tian, D.D.; Shen, Y.

    2014-12-15

    The strain controlled low cycle fatigue properties of the studied gray cast iron for engine cylinder blocks were investigated. At the same total strain amplitude, the low cycle fatigue life of the studied material at 523 K was higher than that at 423 K. The fatigue behavior of the studied material was characterized as cyclic softening at any given total strain amplitude (0.12%–0.24%), which was attributed to fatigue crack initiation and propagation. Moreover, this material exhibited asymmetric hysteresis loops due to the presence of the graphite lamellas. Transmission electron microscopy analysis suggested that cyclic softening was also caused by the interactions of dislocations at 423 K, such as cell structure in ferrite, whereas cyclic softening was related to subgrain boundaries and dislocation climbing at 523 K. Micro-analysis of specimen fracture appearance was conducted in order to obtain the fracture characteristics and crack paths for different strain amplitudes. It showed that the higher the temperature, the rougher the crack face of the examined gray cast iron at the same total strain amplitude. Additionally, the microcracks were readily blunted during growth inside the pearlite matrix at 423 K, whereas the microcracks could easily pass through pearlite matrix along with deflection at 523 K. The results of fatigue experiments consistently showed that fatigue damage for the studied material at 423 K was lower than that at 523 K under any given total strain amplitude. - Highlights: • The low cycle fatigue behavior of the HT250 for engine cylinder blocks was investigated. • TEM investigations were conducted to explain the cyclic deformation response. • The low cycle fatigue cracks of HT250 GCI were studied by SEM. • The fatigue life of the examined material at 523 K is higher than that at 423 K.

  14. High-temperature low cycle fatigue behavior of a gray cast iron

    International Nuclear Information System (INIS)

    The strain controlled low cycle fatigue properties of the studied gray cast iron for engine cylinder blocks were investigated. At the same total strain amplitude, the low cycle fatigue life of the studied material at 523 K was higher than that at 423 K. The fatigue behavior of the studied material was characterized as cyclic softening at any given total strain amplitude (0.12%–0.24%), which was attributed to fatigue crack initiation and propagation. Moreover, this material exhibited asymmetric hysteresis loops due to the presence of the graphite lamellas. Transmission electron microscopy analysis suggested that cyclic softening was also caused by the interactions of dislocations at 423 K, such as cell structure in ferrite, whereas cyclic softening was related to subgrain boundaries and dislocation climbing at 523 K. Micro-analysis of specimen fracture appearance was conducted in order to obtain the fracture characteristics and crack paths for different strain amplitudes. It showed that the higher the temperature, the rougher the crack face of the examined gray cast iron at the same total strain amplitude. Additionally, the microcracks were readily blunted during growth inside the pearlite matrix at 423 K, whereas the microcracks could easily pass through pearlite matrix along with deflection at 523 K. The results of fatigue experiments consistently showed that fatigue damage for the studied material at 423 K was lower than that at 523 K under any given total strain amplitude. - Highlights: • The low cycle fatigue behavior of the HT250 for engine cylinder blocks was investigated. • TEM investigations were conducted to explain the cyclic deformation response. • The low cycle fatigue cracks of HT250 GCI were studied by SEM. • The fatigue life of the examined material at 523 K is higher than that at 423 K

  15. Local microstructures, Hardness and mechanical properties of a stainless steel pipe-welded joint

    International Nuclear Information System (INIS)

    An experimental investigation is carefully performed into the local microstructures, hardness values and monotonic mechanical properties of the three zones (the base metal, heat affecting zone and weld metal) of 1Cr18Ni9Ti stainless steel pipe-welded joint. The local microstructures are observed by a metallurgical test and a surface replica technology, the local hardness values are measures by a random Vickers hardness test, and the local mechanical properties are characterized by the Ramberg-Osgood and modified Ramberg-Osgood stress-stain relations. The investigation reveals that there are significant differences of the three zones in the local microstructures, hardness values and monotonic mechanical properties, especially of the three zones in the local microstructure, hardness values and monotonic mechanical properties, especially of the weld metal. The weld metal exhibits the largest heterogeneity of local microstructures and monotonic mechanical properties, and the largest scatter of local hardness values. It is necessary to consider these difference and introduce the reliability method to model the scatter in the pipe analysis. In addition, it is verified that a columnar grain structure, which is made up of matrix-rich δ ferrite bands, can characterize the weld metal and the distance between the neighboring rich δ ferrite bands is an appropriate measurement of the columnar grain structure. This measurement is in accordance with the transition point between the microstructural short crack and physical small crack stages, which are generally used for characterizing the short fatigue crack behavior of materials. This indicates that the microstructure controls the fatigue damage character of the present material

  16. 46 CFR 154.524 - Piping joints: Welded and screwed couplings.

    Science.gov (United States)

    2010-10-01

    ... temperature of −55 °C (−67 °F), or warmer. (c) A socket weld fitting with attachment welds is allowed for pipe... warmer. (d) Screwed couplings are allowed for instrumentation and control piping that meets §...

  17. PHC管桩接桩问题的检测%Detection of the PHC pipe pile joint of pile problems

    Institute of Scientific and Technical Information of China (English)

    陈军

    2009-01-01

    概括了低应变动测、高应变动测、静载荷试验及孔内摄像等方法检测PHC管桩时的优缺点,分析了管桩接桩问题产生的原因,进而提出了针对此问题的检测方案,从而避免因桩的接头问题引起的建筑物不均匀沉降.%The merits and drawbacks of low strain dynamic testing, dynamic high strain testing, dead load testing and down hole imaging todetect PHC pipe pile were generalized. The pipe pile joint of pile problems occurring reasons were analyzed, then the detected plan against to the problem was proposed, therefore avoided buildings uneven settlement provoked by pile joints problems.

  18. The forty years of vermicular graphite cast iron development in China (Part Ⅲ

    Directory of Open Access Journals (Sweden)

    QIU han-quan

    2007-11-01

    Full Text Available In China, the research and development of vermicular graphite cast iron (VGCI as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines, mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg. Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace

  19. The forty years of vermicular graphite cast iron development in China (Part 2

    Directory of Open Access Journals (Sweden)

    CHEN Zheng-de

    2007-08-01

    Full Text Available In China, the research and development of vermicular graphite cast iron (VGCI as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines, mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg. Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace

  20. The forty years of vermicular graphite cast iron development in China

    Institute of Scientific and Technical Information of China (English)

    QIU han-quan; CHEN Zheng-de

    2007-01-01

    In China, the research and development of vermicular graphite cast iron (VGCI) as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines,mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg.Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace. Examples of typical

  1. The forty years of vermicular graphite cast iron development in China (PartⅠ

    Directory of Open Access Journals (Sweden)

    CHEN Zheng-de

    2007-05-01

    Full Text Available In China, the research and development of vermicular graphite cast iron (VGCI as a new type of engineering material, were started in the same period as in other developed countries; however, its actual industrial application was even earlier. In China, the deep and intensive studies on VGCI began as early as the 1960s. According to the incomplete statistics to date, more than 600 papers on VGCI have been published by Chinese researchers and scholars at national and international conferences, and in technical journals. More than ten types of production methods and more than thirty types of treatment alloy have been studied. Formulae for calculating the critical addition of treatment alloy required to produce VGCI have been put forward, and mechanisms for explaining the formation of dross during treatment were brought forward. The casting properties, metallographic structure, mechanical and physical properties and machining performance of VGCI, as well as the relationships between them, have all been studied in detail. The Chinese Standards for VGCI and VGCI metallographic structure have been issued. In China, the primary crystallization of VGCI has been studied by many researchers and scholars. The properties of VGCI can be improved by heat treatment and addition of alloying elements enabling its applications to be further expanded. Hundreds of kinds of VGCI castings have been produced and used in vehicles, engines, mining equipment, metallurgical products serviced under alternating thermal load, machinery, hydraulic components, textile machine parts and military applications. The heaviest VGCI casting produced is 38 tons and the lightest is only 1 kg. Currently, the annual production of the VGCI in China is about 200 000 tons. The majority of castings are made from cupola iron without pre-treatment, however, they are also produced from electric furnaces and by duplex melting from cupolaelectric furnaces or blast furnace-electric furnace

  2. Influence of rare earth nanoparticles and inoculants on performance and microstructure of high chromium cast iron

    Institute of Scientific and Technical Information of China (English)

    HOU Yuncheng; WANG You; PAN Zhaoyi; YU Lili

    2012-01-01

    The high chromium cast irons (HCCIs) with rare earth (RE) nanoparticles or inoculants were fabricated in the casting process.The phase compositions and microstructure were analyzed by X-ray diffraction (XRD) and optical microscopy (OM),respectively.The hardness and impact toughness were tested by Rockwel-hardmeter and impacting test enginery.And then,the morphology of fracture was researched by scanning electron microscopy (SEM).The results demonstrated that the phase compositions of HCCIs with addition of RE nanoparticles or inoculants which were M7C3 carbides + α -Fe did not change obviously.However,the prime M7C3 carbides morphology had great changes with the increase of RE nanoparticles,which changed from long lath to granular or island shape.When the content of RE nanoparticles was 0.4 wt.%,the microstructure of high chromium cast iron was refined greatly.The microstructure of carbides was coarser when the addition of RE nanoparticles was higher than 0.4 wt.%.The hardness and impact toughness of HCCIs were improved by addition of RE nanoparticles or inoculants.The impact toughness of HCCIs was increased 36.4% with RE nanoparticles of 0.4 wt.%,but the hardness changed slightly.In addition,the adding of RE nanoparticles or inoculants could reduce the degree of the brittle fracture.Fracture never seemed regular,instead,containing lots of laminates and dimples with the increase of the RE nanoparticles.The results also indicated that the optimal addition amonnt of the RE nanoparticles was 0.4%,under this composition,the microstructure and mechanical property achieved the best cooperation.In addition,through the study of erosion wear rate,when adding 0.4% RE nanoparticles into the HCCIs,the erosion wear rate got the minimum 0.32×10-3 g/mm2,which could increase 51.5% compared with that without any RE nanoparticles.

  3. Nature of Surface Changes in Stamping Tools of Gray and Ductile Cast Iron During Gas and Plasma Nitrocarburizing

    Science.gov (United States)

    Roliński, E.; Konieczny, A.; Sharp, G.

    2009-11-01

    Two cast irons, pearlitic-ferritic gray and ferritic ductile, were plasma and gas nitrocarburized at the same temperature and for the same processing time to produce a compound zone of about 10-14 μm thick. It was demonstrated that both processes caused changes in the surface roughness of the irons, and the most dramatic increase of roughness was observed after gas nitrocarburizing of the gray cast iron. It was shown that the primary reason that the results were not the same is the difference in the nitriding mechanism. Significant penetration of the surface voids and imperfections between the graphite particles and the metallic matrix by ammonia molecules led to the formation of a locally thicker compound zone and a bulging of the metallic matrix above the surface. This phenomenon did not occur in the plasma process and as a result the surface changes were much smaller than in the gas process.

  4. Effect of nanocrystalline TiC powder addition on the hardness and wear resistance of cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, Mansour [Materials and Energy Research Center, P.O. Box 1455-4777, Tehran (Iran, Islamic Republic of)], E-mail: m-razavi@merc.ac.ir; Rahimipour, Mohammad Reza [Materials and Energy Research Center, P.O. Box 1455-4777, Tehran (Iran, Islamic Republic of); Rajabi-Zamani, Amir Hossein [Materials and Energy Research Center, P.O. Box 1455-4777, Tehran (Iran, Islamic Republic of)

    2007-04-25

    In this research, the feasibility of the addition of nanocrystalline TiC particles - synthesized via mechanical alloying - to iron matrix melt was investigated. For the preparation of TiC, impure titanium chips and carbon black were placed in a high-energy ball mill and sampled after different milling time. XRD studies showed that at milling times more than 15 h, TiC was synthesized. It was observed from the peak broadening of the diffraction patterns that the TiC crystallites were in the scale of nanometer. 0.96 wt.% TiC synthesized after 15 h was added to a 4 wt.% C cast iron melt. It was observed that this small amount of TiC was enough to improve the structure, hardness and wear resistance of the cast iron significantly.

  5. Modeling of damage in ductile cast iron – The effect of including plasticity in the graphite noduless

    DEFF Research Database (Denmark)

    Andriollo, Tito; Thorborg, Jesper; Tiedje, Niels Skat;

    2015-01-01

    the assumption of infinitesimal strains and plane-stress conditions. Despite the latter being a limitation with respect to full 3D models, it allows a direct comparison with experimental investigations of damage evolution on the surface of ductile cast iron components, where the stress state is biaxial in nature......In the present paper a micro-mechanical model for investigating the stress-strain relation of ductile cast iron subjected to simple loading conditions is presented. The model is based on a unit cell containing a single spherical graphite nodule embedded in a uniform ferritic matrix, under....... In contrast to previous works on the subject, the material behaviour in both matrix and nodule is assumed to be elasto-plastic, described by the classical J2-flow theory of plasticity, and damage evolution in the matrix is taken into account via Lemaitre’s isotropic model. The effects of residual stresses due...

  6. Microstructure and Property of Hypereutectic High Chromium Cast Iron Prepared by Slope Cooling Body-Centrifugal Casting Method

    Institute of Scientific and Technical Information of China (English)

    Zhifu HUANG; Jiandong XING; Anfeng ZHANG

    2006-01-01

    In this paper, the ring-type ingot of hypereutectic high Cr cast iron was obtained by slope cooling bodycentrifugal casting method (SC-CCM), and its microstructure and impact toughness were investigated, respectively. The results indicated that, first, the primary carbides in the microstructure are prominently finer than those in the hypereutectic high Cr cast iron prepared by conventional casting method. Second, in the ring-type ingot, the primary carbides near radial outer field are finer than those near radial inner field; furthermore, there is dividing field in the microstructure. Finally, the impact toughness values of the specimens impacted on the radial outer face and on the radial inner face are improved respectively about 36% and 138%more than that of the hypereutectic high Cr one prepared by conventional casting method.

  7. Effect of RE Modification and Heat Treatment on Impact Fatigue Property of a Wear Resistant White Cast Iron

    Institute of Scientific and Technical Information of China (English)

    常立民; 刘建华; 张瑞军; 王继东

    2004-01-01

    The morphology of carbides, as well as the generation and propagation of fatigue cracks in a wear resistant white cast iron after impact fatigue test were observed by means of optical microscope and SEM, and the relationship among the content of RE (rare earths) in the wear resistant white cast iron and the heating temperature as well as the length and propagation speed of the fatigue cracks were determined. Based on the obtained results, the effect of RE modification and heat treatment on the impact fatigue property was further studied. Experimental results show that addition of RE can defer the time required for the generation of fatigue cracks, reduce their propagation speed and increase the impact fatigue resistance. The aforesaid effect is more noticeable in case of combined RE modification with heat treatment, which can be attributed to the variation in morphology and the distribution of the eutectic carbide network.

  8. Corrosion inhibition of Eleusine aegyptiaca and Croton rottleri leaf extracts on cast iron surface in 1 M HCl medium

    Science.gov (United States)

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy; Poonkuzhali, Kaliyaperumal; Palvannan, Thayumanavan

    2014-09-01

    The adsorption and corrosion inhibition activities of Eleusine aegyptiaca (E. aegyptiaca) and Croton rottleri (C. rottleri) leaf extracts on cast iron corrosion in 1 M hydrochloric acid solution were studied first time by weight loss and electrochemical techniques viz., Tafel polarization and electrochemical impedance spectroscopy. The results obtained from the weight loss and electrochemical methods showed that the inhibition efficiency increased with inhibitor concentrations. It was found that the extracts acted as mixed-type inhibitors. The addition of halide additives (KCl, KBr, and KI) on the inhibition efficiency has also been investigated. The adsorption of the inhibitors on cast iron surface both in the presence and absence of halides follows the Langmuir adsorption isotherm model. The inhibiting nature of the inhibitors was supported by FT-IR, UV-vis, Wide-angle X-ray diffraction and SEM methods.

  9. Effects of striated laser tracks on thermal fatigue resistance of cast iron samples with biomimetic non-smooth surface

    International Nuclear Information System (INIS)

    In order to enhance the thermal fatigue resistance of cast iron materials, the samples with biomimetic non-smooth surface were processed by Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser. With self-controlled thermal fatigue test method, the thermal fatigue resistance of smooth and non-smooth samples was investigated. The effects of striated laser tracks on thermal fatigue resistance were also studied. The results indicated that biomimetic non-smooth surface was benefit for improving thermal fatigue resistance of cast iron sample. The striated non-smooth units formed by laser tracks which were vertical with thermal cracks had the best propagation resistance. The mechanisms behind these influences were discussed, and some schematic drawings were introduced to describe them.

  10. Hot Corrosion Behavior of High-Chromium, High-Carbon Cast Irons in NaCl-KCl Molten Salts

    Directory of Open Access Journals (Sweden)

    S. Vuelvas-Rayo

    2012-01-01

    Full Text Available A study on the corrosion behavior of a series of experimental high-chromium (18.53–30.48 wt.%, high-carbon (3.82–5.17% cast irons in NaCl-KCl (1 : 1 M at 670°C has been evaluated by using weight loss technique and compared with a 304-type stainless steel. It was found that all castings had a higher corrosion rate than conventional 304SS and that the addition of Cr increased the degradation rate of the cast irons. Additionally, corrosion rate increased by increasing the C contents up to 4.29%, but it decreased with a further increase in its contents. Results are discussed in terms of consumption of the Cr2O3 layer by the melt.

  11. New Mechanism on Synergistic Effect of Nitrite and Triethanolamine Addition on the Corrosion of Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    K. T. Kim

    2016-01-01

    Full Text Available In general, we compared the different inhibition mechanisms of organic inhibitor with that of anodic inhibitor. When triethanolamine or nitrite was added separately to tap water for inhibiting the corrosion of ductile cast iron, large amounts of inhibitor were needed. This is because the corrosion inhibitors had to overcome the galvanic corrosion that occurs between graphite and matrix. In this work, we investigated the corrosion of ductile cast iron in tap water with/without inhibitors. The corrosion rate was measured using chemical immersion test and electrochemical methods, including anodic polarization test. The inhibited surface was analyzed using EPMA and XPS. Test solutions were analyzed by performing FT-IR measurement. When triethanolamine and nitrite coexisted in tap water, synergistic effect built up, and the inhibition effect was ca. 30 times more effective than witnessed with single addition. This work focused on the synergistic effect brought about by nitrite and triethanolamine and its novel mechanism was also proposed.

  12. Shrinkage Behaviour of Spheroidal Graphite Cast Iron in Green and Dry Sand Molds for the Benchmarking of Solidification Simulation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of metallurgical and processing parameters on the formation of shrinkage cavities and porosities in spheroidal graphite cast iron have been studied, considering the parameters of carbon equivalent, inoculation, casting modulus, mold type (green or dry) and pouring temperature within specific ranges of these variables. Based on the orthogonal experiments, the metallurgical and processing parameters of the minimum casting shrinkage and the maximum casting shrinkage were obtained, and the effects of metallurgical and processing parameters on the formation of shrinkage cavities and porosities in spheroidal graphite cast iron castings were discussed. Finally,two regression equations relating these variables to the formation of shrinkage porosity were derived based upon the orthogonal experiments conducted.

  13. A new method of fast measuring surface tension of melt cast iron and its application in graphite shape identification

    OpenAIRE

    Li, Dayong; Dequan SHI; Li, Feng

    2005-01-01

    Surface tension is one of important physical features of melt alloy. Many properties of melt alloy, such as graphite shape of cast iron and modified microstructure of aluminum alloy, can be evaluated by means of surface tension. In order to evaluate and control the melt quality in-situ melting operation, the authors advanced a new method and developed an automatic device for fast measuring surface tension of melt alloy and applied it to the practice of rapid identifying graphite shape of cast...

  14. Effects of MC-Type Carbide Forming and Graphitizing Elements on Thermal Fatigue Behavior of Indefinite Chilled Cast Iron Rolls

    Science.gov (United States)

    Ahiale, Godwin Kwame; Choi, Won-Doo; Suh, Yongchan; Lee, Young-Kook; Oh, Yong-Jun

    2015-11-01

    The thermal fatigue behavior of indefinite chilled cast iron rolls with various V+Nb contents and Si/Cr ratios was evaluated. Increasing the ratio of Si/Cr prolonged the life of the rolls by reducing brittle cementites. Higher V+Nb addition also increased the life through the formation of carbides that refined and toughened the martensite matrix and reduced the thermal expansion mismatch in the microstructure.

  15. Effect of partial remelting time on the initial carbide in semisolid structure of hypereutectic hih Cr cast iron

    OpenAIRE

    Huang, Zhifu; Jiandong XING; He, Wei

    2004-01-01

    In order to review the effect of partial remelting time on the morphology of initial carbides, semisolid ingots of hypereutectic high Cr17 cast iron were remelted at 1 270 ℃ for four different times, and the changing characteristics of shape factor an the equivalent diameter of initial carbides were analyzed quantitatively using a Leica image analyzer. The results indicate that firstly, the evolution process of the initial carbides' morphology undergoes melting, sheroidization and refining d...

  16. Influence of wall thickness of spheroidal cast iron, manufactured in the foundry METAL-ODLEW Sp.J., on its graphite shape index and ultrasonic control index

    Directory of Open Access Journals (Sweden)

    W. Orłowicz

    2009-07-01

    Full Text Available This work presents the results of ultrasonic evaluation of the microstructure of spheroidal cast iron manufactured under production condi-tions at the foundry of Metal Odlew Sp.J. Evaluation of ultrasonic control index sensitiveness to changes of graphite shape index Ss of spheroidal cast iron (type 500-7, utilized modelled stepped castings. The relationship was determined between the shape index of graphite precipitation Ss and the velocity of longitudinal ultrasonic wave cL.

  17. Influence of wall thickness of spheroidal cast iron, manufactured in the foundry METAL-ODLEW Sp.J., on its graphite shape index and ultrasonic control index

    OpenAIRE

    W. Orłowicz; M. Tupaj; M. Mróz; E. Guzik; J. Nykiel; A. Zając; B. Piotrowski

    2009-01-01

    This work presents the results of ultrasonic evaluation of the microstructure of spheroidal cast iron manufactured under production condi-tions at the foundry of Metal Odlew Sp.J. Evaluation of ultrasonic control index sensitiveness to changes of graphite shape index Ss of spheroidal cast iron (type 500-7), utilized modelled stepped castings. The relationship was determined between the shape index of graphite precipitation Ss and the velocity of longitudinal ultrasonic wave cL.

  18. Corrosion inhibition of Eleusine aegyptiaca and Croton rottleri leaf extracts on cast iron surface in 1 M HCl medium

    Energy Technology Data Exchange (ETDEWEB)

    Rajeswari, Velayutham [Department of Chemistry, Periyar University, Salem 636011 (India); Kesavan, Devarayan [Department of Chemistry, Dhirajlal Gandhi College of Technology, Salem 636309 (India); Gopiraman, Mayakrishnan [Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India); Viswanathamurthi, Periasamy, E-mail: viswanathamurthi72@gmail.com [Department of Chemistry, Periyar University, Salem 636011 (India); Poonkuzhali, Kaliyaperumal; Palvannan, Thayumanavan [Department of Bio-Chemistry, Periyar University, Salem 636011 (India)

    2014-09-30

    Graphical abstract: - Highlights: • Eleusine aegyptiaca and Croton rottleri are commonly available, less-toxic and eco-friendly inhibitors for cast iron corrosion. • The active constituents present in extracts adsorbed on the iron surface to inhibit the acidic corrosion. • The higher values of E{sub a} and ΔH{sup *} point out the higher inhibition efficiency noticed for the inhibitors. • Weight loss methods at various temperature and spectral data provides evidence for adsorption mechanism of inhibitors. - Abstract: The adsorption and corrosion inhibition activities of Eleusine aegyptiaca (E. aegyptiaca) and Croton rottleri (C. rottleri) leaf extracts on cast iron corrosion in 1 M hydrochloric acid solution were studied first time by weight loss and electrochemical techniques viz., Tafel polarization and electrochemical impedance spectroscopy. The results obtained from the weight loss and electrochemical methods showed that the inhibition efficiency increased with inhibitor concentrations. It was found that the extracts acted as mixed-type inhibitors. The addition of halide additives (KCl, KBr, and KI) on the inhibition efficiency has also been investigated. The adsorption of the inhibitors on cast iron surface both in the presence and absence of halides follows the Langmuir adsorption isotherm model. The inhibiting nature of the inhibitors was supported by FT-IR, UV–vis, Wide-angle X-ray diffraction and SEM methods.

  19. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    Science.gov (United States)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

    2016-02-01

    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  20. Energy Saving Melting and Revert Reduction Technology: Aging of Graphitic Cast Irons and Machinability

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Von L. [Advanced Technology Inst., Virginia Beach, VA (United States)

    2012-09-19

    The objective of this task was to determine whether ductile iron and compacted graphite iron exhibit age strengthening to a statistically significant extent. Further, this effort identified the mechanism by which gray iron age strengthens and the mechanism by which age-strengthening improves the machinability of gray cast iron. These results were then used to determine whether age strengthening improves the machinability of ductile iron and compacted graphite iron alloys in order to develop a predictive model of alloy factor effects on age strengthening. The results of this work will lead to reduced section sizes, and corresponding weight and energy savings. Improved machinability will reduce scrap and enhance casting marketability. Technical Conclusions: Age strengthening was demonstrated to occur in gray iron ductile iron and compacted graphite iron. Machinability was demonstrated to be improved by age strengthening when free ferrite was present in the microstructure, but not in a fully pearlitic microstructure. Age strengthening only occurs when there is residual nitrogen in solid solution in the Ferrite, whether the ferrite is free ferrite or the ferrite lamellae within pearlite. Age strengthening can be accelerated by Mn at about 0.5% in excess of the Mn/S balance Estimated energy savings over ten years is 13.05 trillion BTU, based primarily on yield improvement and size reduction of castings for equivalent service. Also it is estimated that the heavy truck end use of lighter castings for equivalent service requirement will result in a diesel fuel energy savings of 131 trillion BTU over ten years.

  1. Effect of Ti-V-Nb-Mo addition on microstructure of high chromium cast iron

    Directory of Open Access Journals (Sweden)

    Ma Youping

    2012-05-01

    Full Text Available The effects of trace additions of multi-alloying elements (Ti, Nb, V, Mo on carbides precipitation and as-cast microstructure of eutectic high chromium cast iron containing 2.85wt.%C and 31.0wt.%Cr were investigated from thermodynamic and kinetic considerations. The thermodynamic calculations show that Ti and Nb exist in the multi-alloying system in the forms of TiC and NbC. The formation of VC during the solidification is not feasible from the thermodynamic consideration. XRD analysis shows that the V exists in alloy compounds (VCr2C2, VCrFe8. The first precipitated high melting point particles (TiC, NbC can act as the heterogeneous substrate of M7C3 carbides, which results in significant refinement of the M7C3 carbides. After the addition of alloying elements, C atom diffusion is hindered due to the strong affinities of the strong carbide forming elements for carbon, which decreases the growth rate of carbides. The combined roles of the increase of nucleation rate and the decrease of carbides growth rate lead to the finer microstructure.

  2. The Kinetics and Dry-Sliding Wear Properties of Boronized Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    Dong Mu

    2013-01-01

    Full Text Available Some properties of boride formed on gray cast iron (GCI have been investigated. GCI was boronized by powder-pack method using Commercial LSB-II powders at 1123, 1173, and 1223 K for 2, 4, 6, and 8 h, respectively. Scanning electron microscopy showed that boride formed on the surface of boronized GCI had tooth-shaped morphology. The hardness of boride formed on surfaces of GCI ranged from 1619 to 1343 HV0.025, and quenched and tempered GCI ranged from 400 to 610 HV0.025. The boride formed in the coating layer confirmed by X-ray diffraction analysis was Fe2B single phase. Depending on boronizing time and temperature, the thickness of coating layers on boronized GCI ranged from 26 to 105 μm. The activation energy was 209 kJ/mol for boronized GCI. Moreover, the possibility of predicting the iso-thickness of boride layers variation was studied. Dry-sliding wear tests showed that the wear resistance of boronized sample was greater than that of quenched and tempered sample.

  3. Performance Study of Cryogenically Treated HSS Drills in Drillilg Gray Cast Iron Using Orthogonal Array Technique

    Directory of Open Access Journals (Sweden)

    B.R. Ramji

    2010-08-01

    Full Text Available The objective of this research was to study the performance of cryogenically treated HSS drills for drilling gray cast iron. Drilling experiments were conducted with cutting speeds: 560, 710, 900, 1120 rpm, feeds: 0.05, 0.08, 0.12, 0.19 mm/rev and a constant drill diameter: 8 mm. The cryogenic treatment cycle consisted of cooling the test samples from room temperature to cryogenic temperature of -178.9ºC in 3 h, soaking at cryogenic temperature for 24 h and w arming to room temperature in about 5 h. The thrust force and torque were measured using drill tool dynamometer. The surface roughness (Ra, Rz, Rq and R t of the drilled specimens were measured using talysurf. The experimental lay-out was designed using Taguchi’s Orthogonal Array technique. Signal-to-Noise Ratio analysis was performed to identify the effect of the parameters on the response variables. The treated drills were found superior to the non-treated in all the test conditions in terms of lesser thrust force, torque and also superior surface roughness of the specimens. The tool wear was studied using SEM.

  4. Influence of Mg on Solidification of Hypereutectic Cast Iron: X-ray Radiography Study

    Science.gov (United States)

    Yamane, K.; Yasuda, Hideyuki; Sugiyama, A.; Nagira, T.; Yoshiya, M.; Morishita, K.; Uesugi, K.; Takeuchi, A.; Suzuki, Y.

    2015-11-01

    Radiography using a synchrotron radiation X-ray source was performed to examine solidification and melting behaviors in hypereutectic cast iron specimens containing 0.002 and 0.05mass pctMg. The solidification sequence in the alloy containing 0.002mass pctMg was (1) nucleation and growth of graphite particles of which transformed to a flake-like shape, (2) growth of γ-Fe dendrites, (3) nucleation of graphite particles ahead of the interface just prior to the eutectic solidification, and (4) the eutectic solidification. In contrast, (1) and (2) occurred nearly at the same time in the specimen containing 0.05 mass pct Mg. The addition of 0.05mass pctMg significantly reduced the temperature range in which the graphite particles grew as the primary phase. Image-based analysis of melting behavior showed that even 0.05 mass pct addition was sufficient to modify the phase equilibrium of the liquid, γ-Fe, and graphite phases. Thus, the observed influence of Mg on the solidification sequence was attributed to the modification of the phase equilibrium. The influence was consistently explained by considering the shift of the eutectic composition to the carbon side in the pseudo-ternary system. It was also suggested that supersaturation of carbon in the melt increased as the temperature decreased even though the primary graphite particles existed. The supersaturation may cause the nucleation of the graphite particles just before the eutectic solidification.

  5. Improving chill control in iron powder treated slightly hypereutectic grey cast irons

    Directory of Open Access Journals (Sweden)

    Iulian Riposan

    2011-05-01

    Full Text Available Recent studies revealed that in eutectic to slightly hypereutectic grey irons (CE = 4.3%-4.5% the presence of austenite dendrites provides an opportunity to improve the cast iron properties, as a high number of eutectic cells are “reinforced” by austenite dendrites. An iron powder addition proved to be important by promoting dendritic austenite in hypereutectic irons, but was accompanied by adverse effect on the characteristics of potential nuclei for graphite. The purpose of the present paper is to investigate the solidification pattern of these irons. Chill wedges with different cooling moduli (CM = 0.11 – 0.43 cm were poured in resin bonded sand and metal moulds. Relative clear / mottled / total chill measurement criteria were applied. Iron powder additions led to a higher chill tendency, while single inoculation showed the strongest graphitizing effect. The various double treatments show an intermediate position, but the inoculant added after iron powder appears to be the most effective in reducing base iron chill tendency, for all cooling moduli and chill evaluation parameters. This performance reflects the improved properties of (Mn,XS polygonal compounds as nucleation sites for graphite, especially in resin bonded sand mould castings. Both austenite and graphite nucleation benefit from a double addition of iron powder + inoculant, with positive effect on the final structure and chill tendency.

  6. The effect of heat treatment on the gouging abrasion resistance of alloy white cast irons

    Science.gov (United States)

    Are, I. R. S.; Arnold, B. K.

    1995-02-01

    A series of heat treatments was employed to vary the microstructure of four commercially important alloy white cast irons, the wear resistance of which was then assessed by the ASTM jaw-crusher gouging abrasion test. Compared with the as-cast condition, standard austenitizing treatments produced a substantial increase in hardness, a marked decrease in the retained aus-tenite content in the matrix, and, in general, a significant improvement in gouging abrasion resistance. The gouging abrasion resistance tended to decline with increasing austenitizing tem-perature, although the changes in hardness and retained austenite content varied, depending on alloy composition. Subcritical heat treatment at 500 ° following hardening reduced the retained austenite content to values less than 10 pct, and in three of the alloys it caused a significant fall in both hardness and gouging abrasion resistance. The net result of the heat treatments was the development of optimal gouging abrasion resistance at intermediate levels of retained aus-tenite. The differing responses of the alloys to both high-temperature austenitizing treatments and to subcritical heat treatments at 500 ° were related to the effects of the differing carbon and alloying-element concentrations on changes in the M s temperature and secondary carbide precipitation.

  7. Numerical Modelling of Mechanical Integrity of the Copper-Cast Iron Canister. A Literature Review

    International Nuclear Information System (INIS)

    This review article presents a summary of the research works on the numerical modelling of the mechanical integrity of the composite copper-cast iron canisters for the final disposal of Swedish nuclear wastes, conducted by SKB and SKI since 1992. The objective of the review is to evaluate the outstanding issues existing today about the basic design concepts and premises, fundamental issues on processes, properties and parameters considered for the functions and requirements of canisters under the conditions of a deep geological repository. The focus is placed on the adequacy of numerical modelling approaches adopted in regards to the overall mechanical integrity of the canisters, especially the initial state of canisters regarding defects and the consequences of their evolution under external and internal loading mechanisms adopted in the design premises. The emphasis is the stress-strain behaviour and failure/strength, with creep and plasticity involved. Corrosion, although one of the major concerns in the field of canister safety, was not included

  8. APPLICATION OF TAGUCHI AND ANOVA IN OPTIMIZATION OF PROCESS PARAMETERS OF LAPPING OPERATION FOR CAST IRON

    Directory of Open Access Journals (Sweden)

    P.R. Parate

    2013-06-01

    Full Text Available Lapping appears like a miraculous process, because it can produce surfaces that are perfectly flat, perfectly round, perfectly smooth, perfectly sharp, or perfectly accurate. Under the correct circumstances, it can impart or improve precise geometry (flatness, roundness, etc., improve surface finish, improve surface quality, achieve high dimensional accuracy (length, diameter, etc., improve angular accuracy (worm gears, couplings, etc., improve fit, and above all, sharpen the tools. This paper presents research on calculating the material removal rate for a machining component by the lapping process. The cast iron sample with an outer diameter of 50 mm and an inner diameter of 45 mm was tested on a single plate tabletop lapping machine. Experiments based on design of experiments were conducted by varying lapping load, lapping time, paste concentration, lapping fluid, and by using different types of abrasives. The Taguchi statistical method has been used in this work. Optimum machining parameters for material removal rate are estimated and verified with experimental results and are found to be in good agreement. The confirmation test exhibits high material removal rate by using Al2O3 abrasive particles together with oil as a carrier fluid under the impression of high load. Further material removal rate increases with an increase in lapping load and time.

  9. Observation of Nanometric Silicon Oxide Bifilms in a Water-Atomized Hypereutectic Cast Iron Powder

    Science.gov (United States)

    Boisvert, Mathieu; Christopherson, Denis; L'Espérance, Gilles

    2016-06-01

    This study investigated the reasons for the irregular structure of primary graphite nodules that were formed in a hypereutectic cast iron powder during water atomization. The graphite nodules contain a significant amount of micron-sized pores and multiple nanometric voids that formed from silicon oxide bifilms. The bifilms theory is often used to explain the mechanisms responsible for the presence of pores in castings. However, even if many results presented in the literature tend to corroborate the existence of bifilms, to this date, only indirect evidences of their existence were presented. The observations presented in this paper are the first to show the double-sided nature of these defects. These observations support the bifilms theory and give an explanation for the presence of porosities in castings. The bifilms were used as substrate for graphite growth during solidification. The irregular structure of the graphite nodules is a consequence of the rather random structure of the bifilms that were introduced in the melt as a result of turbulences on the surface of the melt during pouring. The confirmation of the existence of bifilms can contribute to the understanding of the mechanical properties of various metallic parts.

  10. Formation of VC- composites surface layers on spheroidized graphite cast iron by laser surface cladding process

    Directory of Open Access Journals (Sweden)

    Essam R.I. Mahmoud

    2015-01-01

    Full Text Available Spheroidal graphite cast iron was laser cladded with VC powder of 44-53 μm particle size using YAG Fiber laser at 500, 1000, and 1500 W processing power and fixed travelling speed of 4 mm/s. The powder was preplaced on the surface of the specimens with 0.5 mm thickness. To prevent the oxidation, argon gas was used as a shielding gas. After the treatment, three zones were resulted: build-up (cladding, fusion, and heat affected zones. The build-up zone was a composite structure consisted of VC particles/dendrites dispersed in a matrix of martensite, carbides and ledeburite structure. At 500 W, most of the VC particles were appeared as their original large size. When the laser power was increased to 1000 W or more, the VC particles were melted and then re-solidified in the form of fine dendrites. The surface hardness of the cladded area was remarkably improved. As the distance from the free surface increases, the hardness decreases. The average hardness value at the surface treated by 500 W was about 710 HV (3 times of the hardness of substrate, while it reached to about 1340 HV and 1520 HV at powers of 1000 W and 1500 W, respectively. The wear resistance of the laser treated samples was improved at all investigated laser processing powers, especially at 1000W and 1500 W.

  11. Application of Time-series Analysis in Control of Chemical Composition of Grey Cast Iron

    Directory of Open Access Journals (Sweden)

    M. Perzyk

    2012-12-01

    Full Text Available The aim of the paper was an attempt at applying the time-series analysis to the control of the melting process of grey cast iron inproduction conditions. The production data were collected in one of Polish foundries in the form of spectrometer printouts. The quality of the alloy was controlled by its chemical composition in about 0.5 hour time intervals. The procedure of preparation of the industrial data is presented, including OCR-based method of transformation to the electronic numerical format as well as generation of records related to particular weekdays. The computations for time-series analysis were made using the author’s own software having a wide range of capabilities, including detection of important periodicity in data as well as regression modeling of the residual data, i.e. the values obtained after subtraction of general trend, trend of variability amplitude and the periodical component. The most interesting results of the analysis include: significant 2-measurements periodicity of percentages of all components, significance 7-day periodicity of silicon content measured at the end of a day and the relatively good prediction accuracy obtained without modeling of residual data for various types ofexpected values. Some practical conclusions have been formulated, related to possible improvements in the melting process controlprocedures as well as more general tips concerning applications of time-series analysis in foundry production.

  12. Thermal energy storage using Prestressed Cast Iron Vessels (PCIV). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gilli, P.V.; Beckmann, G.; Schilling, F.E.

    1977-06-01

    The wide-spread application of thermal energy and high-pressure air storage to electric power generation has so far been hampered by the lack of large high-pressure storage vessels of reasonable cost. Welded steel vessels are too expensive for this purpose. However, the Prestressed Cast Iron Vessel (PCIV), developed as a nuclear reactor pressure vessel by Siempelkamp Giesserei KG of Krefeld, FRG, has the potential of complying with these requirements. Applications of the PCIV include: high-pressure air storage for the quick start-up of open cycle gas turbines; pressurized high-temperature sensible heat storage by means of solids with a gaseous heat transfer medium for closed cycle gas turbines of future solar power stations; and pressurized hot water storage for nuclear, solar, or coal-fired steam power plants, employing either separate peaking turbines or overloadable main turbine sets. A reference PCIV of 8000 m/sup 3/, 275/sup 0/C, with hot going walls and cold going tendons was developed, designed, and stress-analysed. A parametric study showed that pressures between 4 and 8 MPa and L/D ratios larger than 4 should be optimal. Cost of the reference vessel is about $10,000,000 or 33 to 50 $/kWh electric energy stored. Cost of peak power will be from 30 to 100 mills/kWh, depending on many parameters.

  13. Effects of Silicon on Mechanical Properties and Fracture Toughness of Heavy-Section Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    Liang Song

    2015-01-01

    Full Text Available The effects of silicon (Si on the mechanical properties and fracture toughness of heavy-section ductile cast iron were investigated to develop material for spent-nuclear-fuel containers. Two castings with different Si contents of 1.78 wt.% and 2.74 wt.% were prepared. Four positions in the castings from the edge to the center, with different solidification cooling rates, were chosen for microstructure observation and mechanical properties’ testing. Results show that the tensile strength, elongation, impact toughness and fracture toughness at different positions of the two castings decrease with the decrease in cooling rate. With an increase in Si content, the graphite morphology and the mechanical properties at the same position deteriorate. Decreasing cooling rate changes the impact fracture morphology from a mixed ductile-brittle fracture to a brittle fracture. The fracture morphology of fracture toughness is changed from ductile to brittle fracture. When the Si content exceeds 1.78 wt.%, the impact and fracture toughness fracture morphology transforms from ductile to brittle fracture. The in-situ scanning electronic microscope (SEM tensile experiments were first used to observe the dynamic tensile process. The influence of the vermicular and temper graphite on fracture formation of heavy section ductile iron was investigated.

  14. Eutectic cell and nodule count as the quality factors of cast iron

    Directory of Open Access Journals (Sweden)

    E. Fraś

    2008-10-01

    Full Text Available In this work the predictions based on a theoretical analysis aimed at elucidating of eutectic cell count or nodule counts N wereexperimentally verified. The experimental work was focused on processing flake graphite and ductile iron under various inoculationconditions in order to achieve various physicochemical states of the experimental melts. In addition, plates of various wall thicknesses, s were cast and the resultant eutectic cell or nodule counts were established. Moreover, thermal analysis was used to find out the degree of maximum undercooling for the graphite eutectic, Tm. A relationship was found between the eutectic cell or nodule count and the maximum undercooling Tm.. In addition it was also found that N can be related to the wall thickness of plate shaped castings. Finally, the present work provides a rational for the effect of technological factors such as the melt chemistry, inoculation practice, and holding temperature and time on the resultant cell count or nodule count of cast iron. In particular, good agreement was found between the predictions of the theoretical analysis and the experimental data.

  15. Effects of slope plate variable and reheating on semi-solid structure of ductile cast iron

    Institute of Scientific and Technical Information of China (English)

    M. Nili-Ahmadabadi; F. Pahlevani; P. Babaghorbani

    2008-01-01

    Semi-solid metal casting and forming are known as a promising process for a wide range of metal alloys production. In spite of growing application of semi-solid processed light alloys, a few works have been reported about semi-solid processing of iron and steel. In this research inclined plate was used to change dendritic structure of iron to globular one. The effects of length and slope of plate on the casting structure were examined. The results show that the process can effectively change the dendritic structure to globular. In the slope plate angle of 7.5°and length of 560 mm with cooling rate of 67K·s-1 the optimum nodular graphite and solid globular particle were achieved.The results also show that by using slope plate inoculant fading can be prevented more easily since the total time of process is rather short.In addition, the semi-solid ductile cast iron prepared by inclined plate method, was reheated to examine the effect of reheating conditions on the microstructure and coarsening kinetics of the alloy. Solid fraction at different reheating temperatures and holding time was obtained and based on these results the optimum reheating temperature range was determined.

  16. A mathematical model for electrochemical chloride removal from marine cast iron artifacts

    Institute of Scientific and Technical Information of China (English)

    Weizhen OUYANG; Xia CAO; Ning WANG

    2009-01-01

    The aim of this article was to theoretically study diffusion and migration of chlo-ride ions during electrochemical chloride removal. The proposed model would enable optimization of its application by predicting the optimal treatment time and current combination. A mathematical model for simulating the transport behavior of chloride ions was developed by consideration of diffusion and migration of chloride ions when a constant DC current density was applied through the marine cast iron artifacts. The corresponding tests were conducted to validate the mathematical model. This model predicted the data of the extraction ratio of the chloride ion that correlated satisfac-torily with the experimental values. An important issue in electrochemical chloride removal was to understand how chloride ions moved, taking account of diffusion and migration of chloride ions and the release of binding chloride ions. The effects of the treatment time, externally applied current density, chloride diffusion coefficient, and rate constant of release of binding chloride ion on chloride removal are studied. The specific quantitative details applied to one-dimensional model were discussed here. This article has proposed a mathematical model for the first time, which was showed to be a useful tool that can reveal the ionic transport mechanism and optimize the application during electrochemical chloride removal.

  17. Microstructure and properties of Ti–Nb–V–Mo-alloyed high chromium cast iron

    Indian Academy of Sciences (India)

    Youping Ma; Xiulan Li; Yugao Liu; Shuyi Zhou; Xiaoming Dang

    2013-10-01

    The correlations of microstructure, hardness and fracture toughness of high chromium cast iron with the addition of alloys (titanium, vanadium, niobium and molybdenum) were investigated. The results indicated that the as-cast microstructure changed from hypereutectic, eutectic to hypoeutectic with the increase of alloy contents. Mo dissolved in austenite and increased the hardness by solid solution strengthening. TiC and NbC mainly existed in austenite and impeded the austenite dendrite development. V existed in multicomponent systems in forms of V alloy compounds (VCrFe8 and VCr2C2).With the increase of alloy additions, carbides size changed gradually from refinement to coarseness, hardness and impact toughness were increased and then decreased. Compared with the fracture toughness (6 J/cm2) and hardness (50.8HRC) without any alloy addition, the toughness and hardness at 0.60 V–0.60Ti–0.60Nb–0.35Mo (wt%) additions were improved and achieved to 11 J/cm2 and 58.9HRC, respectively. The synergistic roles of Ti, Nb, V and Mo influenced the solidification behaviour of alloy. The refinement of microstructure and improvement of carbides morphologies, size and distribution improved the impact toughness.

  18. Application of Averaged Voronoi Polyhedron in the Modelling of Crystallisation of Eutectic Nodular Graphite Cast Iron

    Directory of Open Access Journals (Sweden)

    A.A. Burbelko

    2013-01-01

    Full Text Available The study presents a mathematical model of the crystallisation of nodular graphite cast iron. The proposed model is based on micro- andmacromodels, in which heat flow is analysed at the macro level, while micro level is used for modelling of the diffusion of elements. The use of elementary diffusion field in the shape of an averaged Voronoi polyhedron [AVP] was proposed. To determine the geometry of the averaged Voronoi polyhedron, Kolmogorov statistical theory of crystallisation was applied. The principles of a differential mathematical formulation of this problem were discussed. Application of AVP geometry allows taking into account the reduced volume fraction of the peripheral areas of equiaxial grains by random contacts between adjacent grains.As a result of the simulation, the cooling curves were plotted, and the movement of "graphite-austenite" and "austenite-liquid” phaseboundaries was examined. Data on the microsegregation of carbon in the cross-section of an austenite layer in eutectic grains wereobtained. Calculations were performed for different particle densities and different wall thicknesses. The calculation results were compared with experimental data.

  19. Elastoplastic pipe-soil interaction analyses of partially-supported jointed water mains

    Institute of Scientific and Technical Information of China (English)

    Yu SHAO; Tu-qiao ZHANG

    2008-01-01

    Water distribution networks are essential components of water supply systems.The combination of pipe structural deterioration and mechanics leads to the failure of pipelines.A physical model for estimating the pipe failure must include both the pipe deterioration model and mechanics model.Winkler pipe-soil interaction(WPSI),an analytical mechanics model developed by Rajani and Tesfamariam(2004),takes external and internal loads,temperature changes,loss of bedding support,and the elastoplastic effect of soil into consideration.Based on the WPSI model,a method to evaluate the elastic and plastic areas was proposed in the present study.An FEM model based on pipe-soil interaction(PSI)element was used to verify the analytical model.Sensitivity analyses indicate that the soft soil,long pipe and high temperature induced the axial plastic deformation more likely,which,however,may not occur in normal scenarios.The soft soil,pipes in small diameters,long unsupported bedding are prone to form flexural plastic area.The results show that the pipes subjected to the same loads have smaller stresses in the elastoplastic analysis than elastic analysis.The difference,however,is slight.

  20. Inelastic behavior of a dissimilar-metal-welded pipe transition joint: comparison of experimental measurements and analytical prediction

    International Nuclear Information System (INIS)

    The subject study involved the prediction and observed behavior of a dissimilar metal pipe joint made from 2 1/4 Cr-1Mo steel welded to Type 316 austenitic stainless steel using a nickel-base filler metal, ERNiCr-3. A two-dimensional axi-symmetric finite element model was employed in the analysis, with certain assumptions made relative to the initial stress state of the joint. Internal pressure and thermal loadings which simulated the test conditions experienced by the joint, were used as inputs. Uni-axial stress-strain relationships and creep equations were applied to the multi-axial stress state through the concept of effective stress and equivalent strain. The analysis indicated that the loading history during the preparatory period (before acutal service) has a significant effect on the behavior of the transition joint in its early service life. The magnitudes of the stresses created at the vicinity of the dissimilar metal interfaces, mainly due to the differences in thermal expansions of the metals, are sufficient to yield the metals, and fast thermal down transients during service will induce more yielding of the metals before shakedown occurs. Calculated plastic ratchetting and creep responses of the joint metals were compared with ORNL strain measurements of the test joint. Very good agreement was shown to exist between the predictions and measurements

  1. Heat Treatment Effect on Microstructure, Hardness and Wear Resistance of Cr26 White Cast Iron

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shaoping; SHEN Yehui; ZHANG Hao; CHEN Dequan

    2015-01-01

    High chromium cast iron(HCCI) is taken as material of coal water slurry pump impeller, but it is susceptible to produce serious abrasive wear and erosion wear because of souring of hard coal particles. The research on optimization of heat treatments to improve abrasive wear properties of HCCI is insufficient, so effect of heat treatments on the microstructure, hardness, toughness, and wear resistance of Cr26 HCCI is investigated to determine the optimal heat treatment process for HCCI. A series of heat treatments are employed. The microstructures of HCCI specimens are examined by using optical microscopy and scanning electron microscopy. The hardness and impact fracture toughness of as-cast and heat treated specimens are measured. The wear tests are assessed by a Type M200 ring-on block wear tester. The results show the following: With increase of the quenching temperature from 950℃ to 1050℃, the hardness of Cr26 HCCI increased to a certain value, kept for a time and then decreased. The optimal heat treatment process is 2 h quenching treatment at 1000℃, followed by a subsequent 2 h tempering at 400℃. The hardness of HCCI is related to the precipitation and redissolution of secondary carbides in the process of heat treatment. The subsequent tempering treatment would result in a slight decrease of hardness but increase of toughness. The wear resistance is much related to the “supporting” effect of the matrix and the“protective” effect of the hard carbide embedded in the matrix, and the wear resistance is further dependent on the hardness and the toughness of the matrix. This research can provide an important insight on developing an optimized heat treatment method to improve the wear resistance of HCCI.

  2. Heat treatment effect on microstructure, hardness and wear resistance of Cr26 white cast iron

    Science.gov (United States)

    Zhou, Shaoping; Shen, Yehui; Zhang, Hao; Chen, Dequan

    2015-01-01

    High chromium cast iron(HCCI) is taken as material of coal water slurry pump impeller, but it is susceptible to produce serious abrasive wear and erosion wear because of souring of hard coal particles. The research on optimization of heat treatments to improve abrasive wear properties of HCCI is insufficient, so effect of heat treatments on the microstructure, hardness, toughness, and wear resistance of Cr26 HCCI is investigated to determine the optimal heat treatment process for HCCI. A series of heat treatments are employed. The microstructures of HCCI specimens are examined by using optical microscopy and scanning electron microscopy. The hardness and impact fracture toughness of as-cast and heat treated specimens are measured. The wear tests are assessed by a Type M200 ring-on block wear tester. The results show the following: With increase of the quenching temperature from 950 °C to 1050 °C, the hardness of Cr26 HCCI increased to a certain value, kept for a time and then decreased. The optimal heat treatment process is 2 h quenching treatment at 1000 °C, followed by a subsequent 2 h tempering at 400 °C. The hardness of HCCI is related to the precipitation and redissolution of secondary carbides in the process of heat treatment. The subsequent tempering treatment would result in a slight decrease of hardness but increase of toughness. The wear resistance is much related to the "supporting" effect of the matrix and the "protective" effect of the hard carbide embedded in the matrix, and the wear resistance is further dependent on the hardness and the toughness of the matrix. This research can provide an important insight on developing an optimized heat treatment method to improve the wear resistance of HCCI.

  3. The Role of Silicon in the Solidification of High-Cr Cast Irons

    Science.gov (United States)

    Bedolla-Jacuinde, A.; Rainforth, M. W.; Mejía, I.

    2013-02-01

    This work analyzes the effect of different additions of silicon (0 to 5.0 pct) on the structure of a high-Chromium white cast iron, with chromium content of 16.8 pct and carbon 2.56 pct. The alloys were analyzed in both as-cast and heat-treated conditions. Casting was undertaken in metallic molds that yielded solidification rates faster than in commercial processes. Nevertheless, there was some degree of segregation of silicon; this segregation resulted in a refinement in the microstructure of the alloy. Silicon also generated a greater influence on the structure by destabilizing the austenitic matrix, and promoted greater precipitation of eutectic carbides. Above 3 pct silicon, pearlite formation occurred in preference to martensite. After the destabilization heat treatment, the matrix structure of the irons up to 3 pct Si consisted of secondary carbides in a martensitic matrix with some retained austenite; higher Si additions produced a ferritic matrix. The different as-cast and heat-treated microstructures were correlated with selected mechanical properties such as hardness, matrix microhardness, and fracture toughness. Silicon additions increased matrix microhardness in the as-cast conditions, but the opposite phenomenon occurred in the heat-treated conditions. Microhardness decreased as silicon content was increased. Bulk hardness showed the same behavior. Fracture toughness was observed to increase up to 2 pct Si, and then decreased for higher silicon contents. These results are discussed in terms of the effect of eutectic carbides' size and the resulting matrix due to the silicon additions.

  4. Development of ELID mirror surface grinding by cast iron bond grinding wheel. Ohkochi memorial technology prize; Chutetsu bond toishi ni yoru denkai inpurosesu doresshingu (ELID) kyomen kensakuho no kaihatsu. Okochi kinen gijutsusho jusho ni yosete

    Energy Technology Data Exchange (ETDEWEB)

    Omori, H.; Takahashi, I. [Institute of Physical and Chemical Research, Tokyo (Japan); Nakagawa, T. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Hagiuda, Y.; Karikome, K. [Tokyo Metropolitan College of Aeronautical Engineering, Tokyo (Japan)

    1997-08-01

    Development was accomplished on the electrolytic in-process dressing (ELID) mirror surface grinding process using a cast iron bonded grinding wheel. This paper describes the history of the development, which may be summarized as follows: a study was begun on powder forging of cutting chips in 1970; a research was started on powder forging of decarburized cast iron powder; developments were made on powder metallurgy of cast irons and cast iron bonded lapping tools in 1980, and cast iron bonded diamond grinding wheels were put on the market; a high-efficiency grinding process using MC and cast iron fiber-bonded grinding wheels were developed in 1985 and the grinding wheels made therefrom were put on the market; and a study was begun on the ELID grinding in 1987, and marketing was started on power supply, grinding liquid and tools for the ELID grinding process in 1990. Discussions on converting raw materials for the powder forging into cutting chips have triggered developing the cast iron bonded grinding wheel. The cast iron bonded diamond grinding wheel improves dressability and sharpness of conventional grinding wheels. The grinding wheel is fabricated by mixing carbonyl iron powder, diamond grinding grains and cast iron powder, pressing the mixture in a die, sintering it at 1140 degC, and assembling and dressing the sinter. The grinding stone can grind high-tech materials. 4 figs.

  5. Evaluation of residual stress on pipe welded joints using laser interferometry

    International Nuclear Information System (INIS)

    Residual stresses that occur during the welding process, are the main cause of failure and defects in welded structures. This paper, presents the use of an electronic processing laser speckle interferometer to measure the residual stress of a welded pipe for a nuclear power plant. A tensile testing machine was used to evaluate a welded pipe that failed in compression. The inform plane deformation and modulus of elasticity of the base metal and welds were measured using an interferometer. Varying the load on the welded pipe had a larger effect on the deformation of the base metal the other properties of the base metal and welds. The elastic moduli of the base metal and weld of the welded pipe were 202.46 and 212.14 GPa, respectively, the residual stress was measured to be 6.29 MPa.

  6. Corrosion resistance of cast irons and titanium alloys as reference engineered metal barriers for use in basalt geologic storage: a literature assessment

    Energy Technology Data Exchange (ETDEWEB)

    Charlot, L.A.; Westerman, R.E.

    1981-07-01

    A survey and assessment of the literature on the corrosion resistance of cast irons and low-alloy titanium are presented. Selected engineering properties of cast iron and titanium are briefly described; however, the corrosion resistance of cast iron and titanium in aqueous solutions or in soils and their use in a basalt repository are emphasized. In evaluating the potential use of cast iron and titanium as structural barrier materials for long-lived nuclear waste packages, it is assumed that titanium has the general corrosion resistance to be used in relatively thin cross sections whereas the cost and availability of cast iron allows its use even in very thick cross sections. Based on this assumption, the survey showed that: The uniform corrosion of low-alloy titanium in a basalt environment is expected to be extremely low. A linear extrapolation of general corrosion rates with an added corrosion allowance suggests that a 3.2- to 6.4-mm-thick wall may have a life of 1000 yr. Pitting and crevice corrosion are not likely corrosion modes in basalt ground waters. It is also unlikely that stress corrosion cracking (SCC) will occur in the commercially pure (CP) titanium alloy or in palladiumor molybdenum-alloyed titanium materials. Low-alloy cast irons may be used as barrier metals if the environment surrounding the metal keeps the alloy in the passive range. The solubility of the corrosion product and the semipermeable nature of the oxide film allow significant uniform corrosion over long time periods. A linear extrapolation of high-temperature corrosion rates on carbon steels and corrosion rates of cast irons in soils gives an estimated metal penetration of 51 to 64 mm after 1000 yr. A corrosion allowance of 3 to 5 times that suggests that an acceptable cast iron wall may be from 178 to 305 mm thick. Although they cannot be fully assessed, pitting and crevice corrosion should not affect cast iron due to the ground-water chemistry of basalt.

  7. Corrosion resistance of cast irons and titanium alloys as reference engineered metal barriers for use in basalt geologic storage: a literature assessment

    International Nuclear Information System (INIS)

    A survey and assessment of the literature on the corrosion resistance of cast irons and low-alloy titanium are presented. Selected engineering properties of cast iron and titanium are briefly described; however, the corrosion resistance of cast iron and titanium in aqueous solutions or in soils and their use in a basalt repository are emphasized. In evaluating the potential use of cast iron and titanium as structural barrier materials for long-lived nuclear waste packages, it is assumed that titanium has the general corrosion resistance to be used in relatively thin cross sections whereas the cost and availability of cast iron allows its use even in very thick cross sections. Based on this assumption, the survey showed that: The uniform corrosion of low-alloy titanium in a basalt environment is expected to be extremely low. A linear extrapolation of general corrosion rates with an added corrosion allowance suggests that a 3.2- to 6.4-mm-thick wall may have a life of 1000 yr. Pitting and crevice corrosion are not likely corrosion modes in basalt ground waters. It is also unlikely that stress corrosion cracking (SCC) will occur in the commercially pure (CP) titanium alloy or in palladiumor molybdenum-alloyed titanium materials. Low-alloy cast irons may be used as barrier metals if the environment surrounding the metal keeps the alloy in the passive range. The solubility of the corrosion product and the semipermeable nature of the oxide film allow significant uniform corrosion over long time periods. A linear extrapolation of high-temperature corrosion rates on carbon steels and corrosion rates of cast irons in soils gives an estimated metal penetration of 51 to 64 mm after 1000 yr. A corrosion allowance of 3 to 5 times that suggests that an acceptable cast iron wall may be from 178 to 305 mm thick. Although they cannot be fully assessed, pitting and crevice corrosion should not affect cast iron due to the ground-water chemistry of basalt

  8. The Effect of Homogenization Heat Treatment on Thermal Expansion Coefficient and Dimensional Stability of Low Thermal Expansion Cast Irons

    Science.gov (United States)

    Chen, Li-Hao; Liu, Zong-Pei; Pan, Yung-Ning

    2016-05-01

    In this paper, the effect of homogenization heat treatment on α value [coefficient of thermal expansion (10-6 K-1)] of low thermal expansion cast irons was studied. In addition, constrained thermal cyclic tests were conducted to evaluate the dimensional stability of the low thermal expansion cast irons with various heat treatment conditions. The results indicate that when the alloys were homogenized at a relatively low temperature, e.g., 1023 K (750 °C), the elimination of Ni segregation was not very effective, but the C concentration in the matrix was moderately reduced. On the other hand, if the alloys were homogenized at a relatively high temperature, e.g., 1473 K (1200 °C), opposite results were obtained. Consequently, not much improvement (reduction) in α value was achieved in both cases. Therefore, a compound homogenization heat treatment procedure was designed, namely 1473 K (1200 °C)/4 hours/FC/1023 K (750 °C)/2 hours/WQ, in which a relatively high homogenization temperature of 1473 K (1200 °C) can effectively eliminate the Ni segregation, and a subsequent holding stage at 1023.15 K (750 °C) can reduce the C content in the matrix. As a result, very low α values of around (1 to 2) × 10-6 K-1 were obtained. Regarding the constrained thermal cyclic testing in 303 K to 473 K (30 °C to 200 °C), the results indicate that regardless of heat treatment condition, low thermal expansion cast irons exhibit exceedingly higher dimensional stability than either the regular ductile cast iron or the 304 stainless steel. Furthermore, positive correlation exists between the α 303.15 K to 473.15 K value and the amount of shape change after the thermal cyclic testing. Among the alloys investigated, Heat I-T3B (1473 K (1200 °C)/4 hours/FC/1023 K (750 °C)/2 hours/WQ) exhibits the lowest α 303 K to 473 K value (1.72 × 10-6 K-1), and hence has the least shape change (7.41 μm) or the best dimensional stability.

  9. The Effect of Homogenization Heat Treatment on Thermal Expansion Coefficient and Dimensional Stability of Low Thermal Expansion Cast Irons

    Science.gov (United States)

    Chen, Li-Hao; Liu, Zong-Pei; Pan, Yung-Ning

    2016-08-01

    In this paper, the effect of homogenization heat treatment on α value [coefficient of thermal expansion (10-6 K-1)] of low thermal expansion cast irons was studied. In addition, constrained thermal cyclic tests were conducted to evaluate the dimensional stability of the low thermal expansion cast irons with various heat treatment conditions. The results indicate that when the alloys were homogenized at a relatively low temperature, e.g., 1023 K (750 °C), the elimination of Ni segregation was not very effective, but the C concentration in the matrix was moderately reduced. On the other hand, if the alloys were homogenized at a relatively high temperature, e.g., 1473 K (1200 °C), opposite results were obtained. Consequently, not much improvement (reduction) in α value was achieved in both cases. Therefore, a compound homogenization heat treatment procedure was designed, namely 1473 K (1200 °C)/4 hours/FC/1023 K (750 °C)/2 hours/WQ, in which a relatively high homogenization temperature of 1473 K (1200 °C) can effectively eliminate the Ni segregation, and a subsequent holding stage at 1023.15 K (750 °C) can reduce the C content in the matrix. As a result, very low α values of around (1 to 2) × 10-6 K-1 were obtained. Regarding the constrained thermal cyclic testing in 303 K to 473 K (30 °C to 200 °C), the results indicate that regardless of heat treatment condition, low thermal expansion cast irons exhibit exceedingly higher dimensional stability than either the regular ductile cast iron or the 304 stainless steel. Furthermore, positive correlation exists between the α 303.15 K to 473.15 K value and the amount of shape change after the thermal cyclic testing. Among the alloys investigated, Heat I-T3B (1473 K (1200 °C)/4 hours/FC/1023 K (750 °C)/2 hours/WQ) exhibits the lowest α 303 K to 473 K value (1.72 × 10-6 K-1), and hence has the least shape change (7.41 μm) or the best dimensional stability.

  10. Preliminary science report on the directional solidification of hypereutectic cast iron during KC-135 low-G maneuvers

    Science.gov (United States)

    Curreri, P. A.; Stefanescu, D. M.; Hendrix, J. C.

    1983-01-01

    An ADSS-P directional solidification furnace was reconfigured for operation on the KC-135 low-g aircraft. The system offers many advantages over quench ingot methods for study of the effects of sedimentation and convection on alloy formation. The directional sodification furnace system was first flown during the September 1982 series of flights. The microstructure of the hypereutectic cast iron sample solidified on one of these flights suggests a low-g effect on graphite morphology. Further experiments are needed to ascertain that this effect is due to low-gravity and to deduce which of the possible mechanisms is responsible for it.

  11. Microstructure and Wear Behavior of TiC Coating Deposited on Spheroidized Graphite Cast Iron Using Laser Surfacing

    OpenAIRE

    E. R. I. Mahmoud; H. F. El-Labban

    2014-01-01

    Spheroidal graphite cast iron was laser cladded with TiC powder using a YAG fiber laser at powers of 700, 1000, 1500 and 2000 W. The powder was preplaced on the surface of the specimens with 0.5 mm thickness. Sound cladding and fusion zones were observed at 700, 1000 and 1500 W powers. However, at 2000 W, cracking was observed in the fusion zone.  At 700 W, a build-up zone consisted of fine TiC dendrites inside a matrix composed of martensite, cementite (Fe3C), and some blocks of retaine...

  12. Residual stress and microstructure evolution by manufacturing processes for welded pipe joint in austenitic stainless steel type 316L

    International Nuclear Information System (INIS)

    Stress corrosion cracking (SCC) has been observed near the heat affected zone (HAZ) of welded pipe joint made of austenitic stainless steel type 316L, even though sensitization is not observed. Therefore, It can be considered that the effect of residual stress on SCC is more important. In the joining process of pipes, butt-welding is conducted after machining. Residual stress is generated by both processes. In case of welding after machining, it can be considered that residual stress due to machining is changed by welding thermal cycle. In this study, residual stress and microstructure evolution due to manufacturing processes is investigated. Change of residual stress distribution caused by processing history is examined by X-ray diffraction method. Residual stress distribution has a local maximum stress in the middle temperature range of the HAZ caused by processing history. Hardness measurement result also has a local maximum hardness in the same range of the HAZ. By using FE-SEM/EBSD, it is clarified that microstructure shows recovery in the high temperature range of HAZ. Therefore, residual stress distribution is determined by microstructure evolution and superposition effect of processing history. In summary, not only any part of manufacturing processes such as welding or machining but also treating all processes as processing history of pipes are important to evaluate SCC. (author)

  13. Design and testing of equipment for nondestructive detection and identification of the location and dimensions of materials defects, especially of cracks in welded joints of pipe systems

    International Nuclear Information System (INIS)

    The prototype of a testing device for the nondestructive detection and identification of defect location and dimensions in a piping, especially of cracks in welded joints, has been evaluated on a laboratory scale. For a variety of reasons, it was not possible yet to perform trials in an industrial-scale system, as eg. in a power plant pipe system or the like. (orig./BBR)

  14. Practical Usage of Effect of Cold Weldability of Metals in Joint of Plastically Deformable Gasket and Flanges of Detachable Joint of Fuel Pipe-Line

    Science.gov (United States)

    Danchenko, V. G.

    2002-01-01

    The performed investigations of the character of changing the leakage of control gas through flange connections in the process of drawing- up the bolts in to calculation moment and subsequent lowering of bolt loading to zero have shown the following. Gradual reduction of leakage through a gasket occurs in the process of increasing the tightening torque up to its complete absence. But there is no leakage through the unloaded gasket after untwisting all nuts and removal of fastening bolts from flanges. The performed analysis has shown that this effect is caused by cold weldability of the gasket with flanges; this is a result of flowing of its material into microrough holes of contact surfaces of flanges at plastic deformation with formation of strong and dense contact. Some technological methods of formation of undetachable joint have been developed for practical application of this effect. According to one of those methods, drawing- up the gasket is performed with the help of flanges preliminarily. Those bolts are substituted by less strong standard bolts for drawing- up by less moment after achievement of stress needed. Method of pressurization of the joint is more effective when technological detachable flanges and bolts are used for reduction of the gasket up to its plastic state. Those flanges and bolts are removed after drawing- up; after that standard flanges are loaded by the moment used for reception of effort only from pressure of operational medium in the pipe- line (Qoper.m.) because drawing- up of the gasket by effort (Qeff.) that provides its plastic state, is already achieved. Then we exclude the first component (Qeff.) in dependence which is known from technical literature: Qdraw. = Qeff . + Qoper .m. = qFgas. + PFpip. (1), and the final formula for calculation of the effort of drawing- up the joint (in which drawing- up the gasket with provision of cold weldability is carried out preliminarily before drawing- up the standard bolts) is expressed in

  15. Thermal and mechanical properties of e-beam irradiated butt-fusion joint in high-density polyethylene pipes

    Science.gov (United States)

    Vijayan, Vipin; Pokharel, Pashupati; Kang, Min Kwan; Choi, Sunwoong

    2016-05-01

    The effects of electron beam irradiation on the thermal and mechanical properties of a butt-fusion joint in high density polyethylene (HDPE) pipes were investigated. Differential scanning calorimetry, X-ray diffraction, and Fourier transform infra-red spectroscopy of welded samples revealed the changes of crystallinity due to the cross linking effect of electron beam irradiation. The suppression of the degree of crystallinity with increasing the irradiation dose from 0 kGy to 500 kGy indicated that the e-beam radiation induced cross-links among the polymer chains at the weld zone. The cross-link junction at the joint of HDPE pipe prevented chain folding and reorganization leading to the formation of imperfect crystallites with smaller size and also less in content. Tensile test of the welded samples with different dose of e-beam irradiation showed the increased values of the yield stress and Young's modulus as a function of irradiation dose. On the other hand, the elongation at break diminished clearly with increasing the irradiation doses.

  16. Leak-before-break analysis of a dissimilar metal welded joint for connecting pipe-nozzle in nuclear power plants

    International Nuclear Information System (INIS)

    Highlights: ► Leak-before-break (LBB) analysis for a dissimilar metal weld joint (DMWJ) is made. ► Pipe-nozzle geometry and inhomogeneous material property of DMWJ are incorporated. ► LBB behavior of a defect can be assessed by LBB assessment diagram and LBB curve. ► Feasibility region of LBB is enlarged with decreasing load and increasing JR. -- Abstract: This paper presents a leak-before-break (LBB) analysis for a dissimilar metal welded joint (DMWJ) connected the safe end to pipe-nozzle of a reactor pressure vessel of which is relevant to safety of nuclear power plant. Three-dimensional finite element analysis models were built for the DMWJ structure, and the initial inner circumferential surface cracks were postulated at the interface between A508 steel and buttering Alloy82. Based on the elastic–plastic fracture mechanics theory of J-integral, the crack growth stability was analyzed, and the pipe-nozzle geometry effect and inhomogeneous material properties of the DMWJ have been incorporated. Base on the analysis results, the LBB curves and LBB assessment diagrams were constructed for the DMWJ, and effects of applied bending moment loads and J-resistance curves of materials on LBB behavior were analyzed. The results show that the LBB behavior of a defect in the DMWJ under an upmost severe load can be assessed and predicted by plotting the defect size and its propagation path in the LBB assessment diagrams. With decreasing the maximum bending moment load and increasing the crack growth resistance of materials, the ligament instability lines shift upward and the critical crack length lines move to the right in the LBB assessment diagrams, which leads to enlargement of the feasibility region in the LBB behavior

  17. A study of structure and mechanical properties of welded joints in polyethylene pipes

    International Nuclear Information System (INIS)

    The structure and the mechanical properties of a butt weld in a polyethylene pipe were examined and contrasted to non-welded PE pipe. X-ray diffraction, differential scanning calorimeter and fourier transform infra red spectrometer measurements revealed details of axial amorphous and crystal orientation in the original pipe. Contrary to expectations considering the squeeze flow nature of butt-welding, formation of randomly oriented crystal structure was determined in the weld region. Tensile and notched impact tests at ambient and sub-ambient temperatures and varying rates of impact showed that welding consistently reduced resistance to failure. Microscopic evaluation of the brittle fracture surfaces revealed the surface morphology of the welded zone to be coarser than the non-welded PE material

  18. Simulation of Heat Flow in Computational Method and Its Verification on the Structure and Property of Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    S. K. Shaha

    2010-01-01

    Full Text Available Problem statement: The solidification of materials depends on the cooling rate of the materials which is governed by heat flow in the mould and alloy composition. Solidification rate also affects the structure and properties of the materials. Approach: In the present study, the heat flow of cold set resin bonded sand mould was simulated using JL Analyzer FEM analysis software. To verify the model, the gray cast iron was melted at 1350°C temperature and poured into a resin bonded sand mould at 1300°C. Results: It showed that most of the heat-reserve at the junction of the mould which was nearer to the source of liquid metal and the lowest heat-reserve at the end of the mould. So, the solidification rate was very high at the end of the mould wall whereas it was comparatively low near the sprue of the mould. Conclusion: Finally, depending on the heat-flow through the mould, the solidification rate changed the microstructure from chill, mottled and gray cast iron and hardness changed from 95.1 HRB-78.78 HRB.

  19. Effects of heat treatment on mechanical properties and microstructure of tungsten fiber reinforced grey cast iron matrix composites

    Institute of Scientific and Technical Information of China (English)

    Niu Libin; Xu Yunhua; Peng jianHong; Wu Hong

    2009-01-01

    In this study, grey cast iron matrix composites reinforced by different volume fractions of tungsten fibers (Vr=0.95 %, 1.90 %, 2.85 %, 3.80 %) were investigated in as-cast and under the heat treatment temperatures of 1,000℃ and 1,100℃. The microstructure and mechanical properties of the composites were analyzed and tested by means of SEM, micro-hardness tester and three-point bend testing. The results show that with increasing of the volume fraction of tungsten fibers, the composites reinforced by the tungsten fiber have higher flexural strength and modulus than that of cast iron without reinforcement, and the flexural strength increases with the increasing of heat treatment temperatures. Due to diffusion reaction between matrix and reinforcing phases, the process of heat treatment, the number of graphite flakes in the matrix seemingly becomes lower; and some hard carbide particles are formed around the residual tungsten fibers. Not only does the hardness of both matrix and reinforcement change tremendously, but also the region of reinforcement is also extended from the original 0.11 mm to 0.19 mm in radius.

  20. Effect of Ti, Nb, Cr and B on Structure and Mechanical Properties of High Aluminium Cast Iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2013-01-01

    Full Text Available In this work, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a high-aluminium alloys, and thusimprove the production process. The melting conditions employed in this work enabled the formation of a Fe-Al-C liquid solution.Moreover, titanium additions into the liquid allowed the precipitation of TiC. According to this reaction, the extent of carbon removal from the melt is strongly influenced by the amount of Ti additions. Hence, proper titanium levels can result in total removal of carbon from the liquid. Notice from this figure that Ti additions above 4.5%, totally eliminate the undesirable Al4C3 precipitates. Making Cr, Ti, B additions reduces size of FeAl alloys grains. In addition, this work indicates that the high-aluminium cast iron posses high oxidation resistance, exceeding that of high-chromium cast iron and chromium cast steels. Finally, the alloy ductility can be enhanced by additions of dopants such as B and Cr. Hence, additions of 0.03% B and 0.03%B-5% Cr combined with a heat treatment were implemented. As a result, the alloy ductility was significantly improved, where the strain of up to 5.3%, (B alone or 15% (B-Cr were obtained.

  1. Effect of alloying elements on branching of primary austenite dendrites in Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2011-04-01

    Full Text Available Within the research, determined were direction and intensity of influence of individual alloying elements on branching degree of primary austenite dendrites in austenitic cast iron Ni-Mn-Cu. 30 cast shafts dia. 20 mm were analysed. Chemical composition of the alloywas as follows: 2.0 to 3.3 % C, 1.4 to 3.1 % Si, 2.8 to 9.5 % Ni, 0.4 to 7.7 % Mn, 0 to 4.6 % Cu, 0.14 to 0.16 % P and 0.03 to 0.04 % S.Analysis was performed separately for the dendrites solidifying in directional and volumetric way. The average distance "x" between the2nd order arms was accepted as the criterion of branching degree. It was found that influence of C, Si, Ni, Mn and Cu on the parameter "x"is statistically significant. Intensity of carbon influence is decidedly higher than that of other elements, and the influence is more intensive in the directionally solidifying dendrites. However, in the case of the alloyed cast iron Ni-Mn-Cu, combined influence of the alloying elements on solidification course of primary austenite can be significant.

  2. Study of carbon and silicon loss through oxidation in cast iron base metal using rotary furnace for melting

    Directory of Open Access Journals (Sweden)

    Sylvester Olanrewaju OMOLE

    2015-05-01

    Full Text Available The projection of loss of carbon and silicon through oxidation is uncertain phenomenon depending on the furnace used for melting, which affect the carbon equivalent value (CEV of cast iron produced. CEV enhances the fluidity of molten metal as well as having great effects on the mechanical properties of cast products. Study on the way elemental loss takes place during melting with rotary furnace will give idea of approach to minimize the loss. Therefore, the aim of this work is to study the magnitude of the elemental loss with rotary furnace and means to minimize the loss. 60kg of grey cast iron scrap was charged into rotary furnace of 100kg capacity after preheating the furnace for 40 minutes. Graphite and ferrosilicon was added to the charge in order to obtain a theoretical composition of not less than 4.0% carbon and 2.0% silicon. Charges in the furnace were heated to obtain molten metal which was tapped at 1400°C. Tapping was done for casting at three different times. The castings solidified in sand mould and allowed to cool to room temperature in the mould. Castings were denoted as sample 1, 2 and 3. Final compositions of each casting were analyzed with optical light emission spectrometer. Sample 1 has 2.95% carbon and 1.82% silicon. Sample 2 has 2.88% carbon and 1.70% silicon and sample 3 has 2.75% carbon and 1.63% silicon.

  3. The thermal fatigue resistance of vermicular cast iron coupling with H13 steel units by cast-in process

    International Nuclear Information System (INIS)

    This paper focuses on improving the thermal fatigue resistance on the surface of vermicular cast iron coupling with inserted H13 steel blocks that had different cross sections, by cast-in processing. The microstructure of bionic units was examined by scanning electron microscope. Micro-hardness and thermal fatigue resistance of bionic samples with varied cross sections and spacings were investigated, respectively. Results show that a marked metallurgical bonding zone was produced at interface between the inserted H13 steel block and the parent material - a unique feature of the bionic structure in the vermicular cast iron samples. The micro-hardness of the bionic samples has been significantly improved. Thermal resistance of the samples with the circular cross section was the highest and the bionics sample with spacing of 2 mm spacing had a much longer thermal fatigue life, thus resulting in the improvement for the thermal fatigue life of the bionic samples, due to the efficient preclusion for the generation and propagation of crack at the interface of H13 block and the matrix.

  4. Effect of Destabilizing Heat Treatment on Solid-State Phase Transformation in High-Chromium Cast Irons

    Science.gov (United States)

    Efremenko, Vasily; Shimizu, Kazumichi; Chabak, Yuliia

    2013-12-01

    This work describes the influence of secondary carbide precipitation at destabilizing heat treatment on kinetics of austenite phase transformation at a subcritical range of temperatures in high-Cr cast irons, alloyed with 4 to 6 wt pct of Mn or by complex Mn-Ni-Mo (Mn-Cu-Mo). The samples were soaked at 1073 K to 1373 K (800 °C to 1100 °C) (destabilization) or at 573 K to 973 K (300 °C to 700 °C) (subcritical treatment); the combination of destabilization and subcritical treatment was also used. The investigation was carried out with application of optical and electron microscopy and bulk hardness measurement. Time-temperature-transformation (TTT) curves of secondary carbide precipitation and pearlite transformation for as-cast austenite and destabilized austenite were built in this work. It was determined that the secondary carbide precipitation significantly inhibited the pearlite transformation rate at 823 K to 973 K (550 °C to 700 °C). The inhibition effect is more evident in cast irons alloyed with complex Mn-Ni-Mo or Mn-Cu-Mo. The possible reasons for transformation decelerating could be austenite chemical composition change (enriching by Ni, Si, and Cu, and depleting by Cr) and stresses induced by secondary carbide precipitation.

  5. Improvement in Abrasion Wear Resistance and Microstructural Changes with Deep Cryogenic Treatment of Austempered Ductile Cast Iron (ADI)

    Science.gov (United States)

    Šolić, Sanja; Godec, Matjaž; Schauperl, Zdravko; Donik, Črtomir

    2016-10-01

    The application of a deep cryogenic treatment during the heat-treatment processes for different types of steels has demonstrated a significant influence on their mechanical and tribological properties. A great deal of research was conducted on steels, as well as on other kinds of materials, such as hard metal, gray cast iron, aluminum, aluminum alloys, etc., but not on austempered ductile iron (ADI). In this research the influence of a deep cryogenic treatment on the microstructure and abrasive wear resistance of austempered ductile iron was investigated. The ductile cast iron was austempered at the upper ausferritic temperature, deep cryogenically treated, and afterwards tempered at two different temperatures. The abrasion wear resistance was tested using the standard ASTM G65 method. The microstructure was characterized using optical microscopy, field-emission scanning electron microscopy, electron back-scattered diffraction, and X-ray diffraction in order to define the microstructural changes that influenced the properties of the ADI. The obtained results show that the deep cryogenic treatment, in combination with different tempering temperatures, affects the matrix microstructure of the austempered ductile iron, which leads to an increase in both the abrasion wear resistance and the hardness.

  6. Effects of heat treatment on mechanical properties and microstructure of tungsten fi ber reinforced grey cast iron matrix composites

    Directory of Open Access Journals (Sweden)

    Peng jianHong

    2009-11-01

    Full Text Available In this study, grey cast iron matrix composites reinforced by different volume fractions of tungsten fibers (Vr = 0.95 %, 1.90 %, 2.85 %, 3.80 % were investigated in as-cast and under the heat treatment temperatures of 1,000℃ and 1,100℃. The microstructure and mechanical properties of the composites were analyzed and tested by means of SEM, micro-hardness tester and three-point bend testing. The results show that with increasing of the volume fraction of tungsten fibers, the composites reinforced by the tungsten fiber have higher fl exural strength and modulus than that of cast iron without reinforcement, and the fl exural strength increases with the increasing of heat treatment temperatures. Due to diffusion reaction between matrix and reinforcing phases, the process of heat treatment, the number of graphite fl akes in the matrix seemingly becomes lower; and some hard carbide particles are formed around the residual tungsten fi bers. Not only does the hardness of both matrix and reinforcement change tremendously, but also the region of reinforcement is also extended from the original 0.11 mm to 0.19 mm in radius.

  7. Effect of vibration frequency on microstructure and performance of high chromium cast iron prepared by lost foam casting

    Institute of Scientific and Technical Information of China (English)

    Wen-qi Zou; Zhi-guo Zhang; Hao Yang; Wei Li

    2016-01-01

    In the present research, high chromium cast irons (HCCIs) were prepared using the lost foam casting (LFC) process. To improve the wear resistance of the high chromium cast irons (HCCIs), mechanical vibration was employed during the solidiifcation of the HCCIs. The effects of vibration frequency on the microstructure and performance of the HCCIs under as-cast, as-quenched and as-tempered conditions were investigated. The results indicated that the microstructures of the LFC-produced HCCIs were reifned due to the introduction of mechanical vibration, and the hardness was improved compared to that of the aloy without vibration. However, only a slight improvement in hardness was found in spite of the increase of vibration frequency. In contrast, the impact toughness of the as-tempered HCCIs increased with an increase in the vibration frequency. In addition, the wear resistance of the HCCIs was improved as a result of the introduction of vibration and increased with an increase in the vibration frequency.

  8. Effect of vibration frequency on microstructure and performance of high chromium cast iron prepared by lost foam casting

    Directory of Open Access Journals (Sweden)

    Wen-qi Zou

    2016-07-01

    Full Text Available In the present research, high chromium cast irons (HCCIs were prepared using the lost foam casting (LFC process. To improve the wear resistance of the high chromium cast irons (HCCIs, mechanical vibration was employed during the solidification of the HCCIs. The effects of vibration frequency on the microstructure and performance of the HCCIs under as-cast, as-quenched and as-tempered conditions were investigated. The results indicated that the microstructures of the LFC-produced HCCIs were refined due to the introduction of mechanical vibration, and the hardness was improved compared to that of the alloy without vibration. However, only a slight improvement in hardness was found in spite of the increase of vibration frequency. In contrast, the impact toughness of the as-tempered HCCIs increased with an increase in the vibration frequency. In addition, the wear resistance of the HCCIs was improved as a result of the introduction of vibration and increased with an increase in the vibration frequency.

  9. A study on the structure and mechanical properties of vermicular cast iron with pearlitic-ferritic matrix

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2009-07-01

    Full Text Available The results of studies on the use of magnesium alloy in modern cored wire injection method for production of vermicular graphite cast irons were described. The injection of Mg cored wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire (Mg recovery 45% for the production of vermicular graphite cast irons at Giesserei Heunisch GmbH Foundry with the pearlite matrix with about 20%ferrite content. The results of calculations and experiments have indicated the length of the cored wire to be injected basing on the initial sulfur content and weight of the treated melt. The paper presents a microstructure matrix and vermicular graphite in standard sample and different walled castings. The results of numerous trials have shown that the magnesium cored wire process can produce high quality vermicular graphite irons under the specific industrial conditions of the above mentioned foundries.

  10. 钢和铸铁激光淬硬的工艺原理探讨%Technique Principle of Laser Hardening Steeland Cast Iron

    Institute of Scientific and Technical Information of China (English)

    刘文今; 钟敏霖

    2001-01-01

    讨论了钢和铸铁在激光表面淬硬时的物理冶金学过程,提出了激光淬硬获得优良效果的工艺设计依据,介绍了对钢铁零件激光淬硬表层的检验方法。%This paper discussed the physicalmetallurgical process during laser hardening withsteel and cast iron, Presented the technique designprinciple of laser hardening to achieve good resultsIt also introduced the inspection method for laserhardened surface of steel and cast iron.

  11. Residual stress distribution in carbon steel pipe welded joint measured by neutron diffraction

    International Nuclear Information System (INIS)

    In order to estimate crack growth behavior of fatigue and stress corrosion cracking in pipes, the residual stress distribution near the pipe weld region has to be measured through the wall thickness. Since the penetration depth of neutron is deep enough to pass through the thick pipe wall, the neutron diffraction technique for the residual stress measurement is effective for this purpose. At the first step the residual stress distribution near the weld region in a butt-welded carbon steel pipe was measured by the neutron diffraction. Significant stresses extended only to a distance of 30 mm from the center of the weld. The major tensile stresses occurred in the hoop direction in the fusion and heat affected zones of the weldment, and they attained a level greater than 200 MPa through the thickness. While the axial residual stress at the inside surface was 50 MPa, the stress at the outside surface was -100 MPa. The comparison of residual stress distributions measured by the neutron diffraction, the X-ray diffraction and the strain gauge method reveals that the neutron diffraction is the most effective for measuring the residual stress inside the structural components. (author)

  12. Technical Letter Report - Preliminary Assessment of NDE Methods on Inspection of HDPE Butt Fusion Piping Joints for Lack of Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Susan L.; Cumblidge, Stephen E.; Doctor, Steven R.; Hall, Thomas E.; Anderson, Michael T.

    2008-05-29

    The U.S. Nuclear Regulatory Commission (NRC) has a multi-year program at the Pacific Northwest National Laboratory (PNNL) to provide engineering studies and assessments of issues related to the use of nondestructive evaluation (NDE) methods for the reliable inspection of nuclear power plant components. As part of this program, there is a subtask 2D that was set up to address an assessment of issues related to the NDE of high density polyethylene (HDPE) butt fusion joints. This work is being driven by the nuclear industry wanting to employ HDPE materials in nuclear power plant systems. This being a new material for use in nuclear applications, there are a number of issues related to its use and potential problems that may evolve. The industry is pursuing ASME Code Case N-755 entitled “Use of Polyethylene (PE) Plastic Pipe for Section III, Division 1, Construction and Section XI Repair/Replacement Activities” that contains the requirements for nuclear power plant applications of HDPE. This Code Case requires that inspections be performed after the fusion joint is made by visually examining the bead that is formed and conducting a pressure test of the joint. These tests are only effective in general if gross through-wall flaws exist in the fusion joint. The NRC wants to know whether a volumetric inspection can be conducted on the fusion joint that will reliably detect lack-of-fusion conditions that may be produced during joint fusing. The NRC has requested that the work that PNNL is conducting be provided to assist them in resolving this inspection issue of whether effective volumetric NDE can be conducted to detect lack of fusion (LOF) in the butt HDPE joints. PNNL had 24 HDPE pipe specimens manufactured of 3408 material to contain LOF conditions that could be used to assess the effectiveness of NDE in detecting the LOF. Basic ultrasonic material properties were measured and used to guide the use of phased arrays and time-of-flight diffraction (TOFD) work that

  13. Drill pipe downhole unthreading apparatus

    International Nuclear Information System (INIS)

    This paper describes an apparatus for unthreading a threaded connection in a drill string. It comprises: an elongate shaft; fluid powered means for moving the shaft in repeated movement between first and second positions; upper and lower mandrels supporting the shaft and exposed to joints making up the drill string, the mandrels joining together to permit rotation therebetween; upper and lower pipe gripping means cooperatively engaging pipe joints in the drill string wherein the upper pipe gripping means engages a pipe joint above a threaded connection in the pipe string and the lower pipe gripping means engages a pipe joint below the threaded connection in the pipe string; and means coupling the shaft to impart repeated movement through the upper and lower mandrels and pipe gripping means to the pipe joints so that the threaded connection in the pipe string is rotated to unthread

  14. Development of fatigue resistance evaluation method for socket-weld-jointed pipes

    International Nuclear Information System (INIS)

    Vent line, drain line and sampling line in nuclear power station have many socket welded-joints made of austenitic stainless steel. Their slenderness and stagnation yield some potential of vibration-induced cracking and stress corrosion cracking. For the joints under vibration, the authors firstly elucidated their welding-defect-related fatigue strength by using fracture mechanics. It could define the allowable sets of stress amplitude and defect size. Secondly, authors developed an ultra-sonic detecting apparatus by using a focus-type probe and its programmed crawl on socket part. The authors finally measured the stress amplitude and frequency by sticking strain gage on suspected joints, then evaluated the fatigue resistance of the joints. For more efficient procedure, the method of stress amplitude analysis through vibration measurement is being developed. (author)

  15. Survey of tracking systems and rotary joints for coolant piping. Final report, August 15, 1978-August 14, 1978. [Includes patents

    Energy Technology Data Exchange (ETDEWEB)

    Furaus, J P; Gruchalla, M E; Sower, G D

    1980-01-01

    Problems were surveyed and evaluated with respect to solar tracking mechanisms and rotary joints for coolant piping. An analytical development of celestial mechanics, one- and two-axis tracking configurations and the effect of tracking accuracy versus collector efficiency are reported. Daily operational requirements and tracking modes were defined and evaluated. A literature and patent search on solar tracking technology was performed. Tracking system and control system performance specifications were determined. Alternative conceptual tracking approaches were defined and a cost and performance evaluation of a mechanical tracking concept was performed. Fluid coupling service specifications were determined. The cost and performance of several types of actuators and error detectors were evaluated with respect to solar tracking mechanisms.

  16. Technology for residual stress relieving in the pipe-tube plate joint and chuck welding zones in steam generators. Microball cleaning system

    International Nuclear Information System (INIS)

    This study aims to develop a stress relieving method and facility by microball cleaning. 75% of all failures in the steam generator pipes, due mainly to the intergranular attack phenomena and cracking corrosion under stress, occur in the pipe-tube plate joint zones. The experimental stress relieving facility and the experimental tube plate model with chucked pipes were designed and manufactured. The transition zones of the pipe chucking were stress relieved by means of the experimental facility and the results indicate a decrease by 50% of the residual stresses without damaging the pipe material structure. The stress relieving facility could be used in preventive maintenance activities at NPP steam generators. Thus, the risk of pipe crack occurrence in the chuck transition zone is diminished and, consequently, the number of accidental reactor shut-downs decreases as well as the time required by repairs (pipe plugging). The paper contains the following sections: 1. Introduction; 2. Determining the residual stress level; 3. Determining the susceptibility to intergranular attack; 4. Determining the susceptibility to corrosion under stress; 5.Metallographic examination. (authors)

  17. Resistance of Cast Iron Unified Module Recuperator of Heating Furnaces with High-Temperature Thermal Technologies at Machine Building, Automotive and Tractor Enterprises

    Directory of Open Access Journals (Sweden)

    A. P. Nesenchouk

    2010-01-01

    Full Text Available The paper contains a stress analysis in the field of elastic and elastic-plastic wall state of a cast iron module industrial recuperator of high-temperature technology furnaces applied in blank and mechanical assembly production at machine building enterprises.

  18. Mechanism of free sulfur influence on the eutectic cell count and transition from graphite to cementite eutectic in cast iron. Part II. Experimental verification

    Directory of Open Access Journals (Sweden)

    E Fraś

    2010-01-01

    Full Text Available In this work the mechanism of free sulfur influence on the transition from graphite to cementite eutectic in cast iron is experimentally verified. It has been shown that the main impact of free sulfur on the transition from graphite to cementite eutectic consist in reducing the growth rate of graphite eutectic cell.

  19. Measurements of the radioactive inventory of the old effluent pipe line on the BNL site

    International Nuclear Information System (INIS)

    When Berkeley Nuclear Laboratory (BNL) was built, a 3 inch cast iron pipe was laid to carry the radioactive effluent from the BNL effluent treatment plant to the power station for further treatment and/or discharge. In 1980/81 a new pipe line was installed and since then the old line has remained unused. As part of the refurbishment of certain parts of the BNL site currently in progress, the majority of the pipe is to be dug up in two stages, although a small length of the pipe which runs under existing foundations will be left in the ground. This report gives the radioactive inventory of the pipe based on measurements made during the first state of removal. Samples from the trench dug to expose the pipe were taken before and after the removal of the pipe and analysed to determine whether the pipe had leaked and the level of contamination caused by the pipe's removal. (author)

  20. 3D analysis of micro-deformation in VHCF-loaded nodular cast iron by μCT

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, G., E-mail: gottfried.fischer@lqw.mb.uni-dortmund.de [RIF e.V. Institut für Forschung und Transfer, Joseph-von-Fraunhofer-Str. 20, D-44227 Dortmund (Germany); Nellesen, J., E-mail: Jens.Nellesen@rif-ev.de [RIF e.V. Institut für Forschung und Transfer, Joseph-von-Fraunhofer-Str. 20, D-44227 Dortmund (Germany); Anar, N.B., E-mail: nadeembabar.anar@tu-dortmund.de [RIF e.V. Institut für Forschung und Transfer, Joseph-von-Fraunhofer-Str. 20, D-44227 Dortmund (Germany); Ehrig, K., E-mail: Karsten.Ehrig@bam.de [BAM Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, D-12205 Berlin (Germany); Riesemeier, H., E-mail: Heinrich.Riesemeier@bam.de [BAM Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, D-12205 Berlin (Germany); Tillmann, W., E-mail: Wolfgang.Tillmann@udo.edu [Technische Universität Dortmund, Fakultät Maschinenbau, Lehrstuhl für Werkstofftechnologie, D-44221 Dortmund (Germany)

    2013-08-10

    The impact of very high cycle fatigue (VHCF) load conditions on the microstructure of specimens consisting of nodular cast iron is analyzed by means of micro-computed tomography (μCT) utilizing both monochromatic synchrotron radiation and polychromatic X-ray tube radiation. Using 3D μCT, the microstructure in the region of the smallest cross-sections of shouldered round specimens is imaged in different stages of the VHCF loading. By digital image correlation (DIC) of these tomograms strain fields are analyzed three-dimensionally. Strain levels in the range of a few percent were detected. It is proven that a localization of strain allows to predict the site of the crack which precedes and induces the macroscopic failure of the specimens.

  1. Influence of Addition of Briquettes with Dust Content into the Charge of Electric Induction Furnace on Cast Iron Quality

    Directory of Open Access Journals (Sweden)

    A. Pribulová

    2012-09-01

    Full Text Available Foundry dust from blasting and grinding of castings contain a high amount of iron, ergo it is possible its recycling in foundry process.Dust was compacted by briquetting, two kinds of briquettes were prepared (A contained 95% magnetic part of dust from casting blasting+5% bentonite and B contained 95% mixture of dust from casting grinding and magnetic part of dust from casting blasting + 5%bentonite and used as a part of charge into the electric induction furnace. It was found that addition of briquettes has had an influence of a chemical composition of cast iron above all on content of sulphur, phosphorus and silicon. It was not reflected in decrease in tensile strength and in microstructure. Yield of metal from briquettes was not lower then 70%.

  2. Effect of Hot Deformation on Formation and Growth of Thermal Fatigue Crack in Chromium Wear Resistant Cast Iron

    Institute of Scientific and Technical Information of China (English)

    CHANG Li-min; LIU Jian-hua

    2006-01-01

    The formation and growth of thermal fatigue crack in chromium wear resistant cast iron was investigated, and the effect of hot deformation on the crack was analyzed by means of optical microscope and scanning electron microscope and high frequency induction thermal fatigue tester. The results show that eutectic carbide is the main location and passage for initiation and extension of thermal fatigue cracks, hot deformation can improve the eutectic carbide′s morphology and distribution, inhibit the generation and propagation of thermal fatigue cracks. In the experiment, the propagation rate of thermal fatigue crack reduces with the quantity of hot deformation increasing, which was analyzed in the point view of the activation energy of crack propagation.

  3. Constitutive model for flake graphite cast iron automotive brake discs: induced anisotropic damage model under complex loadings

    Science.gov (United States)

    Augustins, L.; Billardon, R.; Hild, F.

    2016-01-01

    The present paper details an elasto-viscoplastic constitutive model for automotive brake discs made of flake graphite cast iron. In a companion paper (Augustins et al. in Contin Mech Thermodyn, 2015), the authors proposed a one-dimensional setting appropriate for representing the complex behavior of the material (i.e., asymmetry between tensile and compressive loadings) under anisothermal conditions. The generalization of this 1D model to 3D cases on a volume element and the associated challenges are addressed. A direct transposition is not possible, and an alternative solution without unilateral conditions is first proposed. Induced anisotropic damage and associated constitutive laws are then introduced. The transition from the volume element to the real structure and the numerical implementation require a specific basis change. Brake disc simulations with this constitutive model show that unilateral conditions are needed for the friction bands. A damage deactivation procedure is therefore defined.

  4. Effect of partial remelting time on the initial carbide in semisolid structure of hypereutectic hih Cr cast iron

    Directory of Open Access Journals (Sweden)

    Zhifu HUANG

    2004-11-01

    Full Text Available In order to review the effect of partial remelting time on the morphology of initial carbides, semisolid ingots of hypereutectic high Cr17 cast iron were remelted at 1 270 ℃ for four different times, and the changing characteristics of shape factor an the equivalent diameter of initial carbides were analyzed quantitatively using a Leica image analyzer. The results indicate that firstly, the evolution process of the initial carbides' morphology undergoes melting, sheroidization and refining during the partial remelting; secondly, the solute diffusion and interface tension take dominant roles at the primary and the middle-final stages respectively in the process of initial carbde evolution; finally, a perfect structure can be obtained by remeltin semisolid ingots at 1 270 ℃ for 15 min.

  5. Development of the white cast iron with niobium alloy, heat treating, to wear of the abrasive resistance

    International Nuclear Information System (INIS)

    This work presents the heat treatment and abrasion tests results of a white cast iron with niobium alloy. The hardening heat treatment were made 950, 1000, 1050 e 110 deg C temperatures cooled by forced air. The tempering treatment were made at 450, 500 e 550 deg C temperatures. The heat treating alloy were compared, in the abrasive tests, with commercial alloys used as hardfacing by welding process in wear pieces. The abrasion tests was realized in pin on disk test. Additional tests were carried out for microstructural characterization to identify the different phases presents in the alloys. In a general way, the alloy studies showed the best wear rate for the heat treatments that results in higher hardness. It performance was superior than that of the commercial alloys. (author)

  6. Constitutive model for flake graphite cast iron automotive brake discs: from macroscopic multiscale models to a 1D rheological description

    Science.gov (United States)

    Augustins, L.; Billardon, R.; Hild, F.

    2016-07-01

    One of the critical points of the thermomechanical fatigue design process is the correct description of the cyclic behavior of the material. This work focuses on the material of automotive brake discs, namely flake graphite cast iron. The specificity of this material is its asymmetric behavior under tensile and compressive loadings, which is due to the shape of graphite that acts as small cracks. Multiscale models inspired from the literature are first presented. They lead to a good description of the material behavior under cyclic loadings. An elastoviscoplastic constitutive model is then proposed in a one-dimensional setting in order to accurately describe cyclic tests from room temperature up to {600^{circ}{C}}.

  7. Constitutive model for flake graphite cast iron automotive brake discs: induced anisotropic damage model under complex loadings

    Science.gov (United States)

    Augustins, L.; Billardon, R.; Hild, F.

    2016-09-01

    The present paper details an elasto-viscoplastic constitutive model for automotive brake discs made of flake graphite cast iron. In a companion paper (Augustins et al. in Contin Mech Thermodyn, 2015), the authors proposed a one-dimensional setting appropriate for representing the complex behavior of the material (i.e., asymmetry between tensile and compressive loadings) under anisothermal conditions. The generalization of this 1D model to 3D cases on a volume element and the associated challenges are addressed. A direct transposition is not possible, and an alternative solution without unilateral conditions is first proposed. Induced anisotropic damage and associated constitutive laws are then introduced. The transition from the volume element to the real structure and the numerical implementation require a specific basis change. Brake disc simulations with this constitutive model show that unilateral conditions are needed for the friction bands. A damage deactivation procedure is therefore defined.

  8. Effect of Manganese on As-Cast Microstructure and Hardening Behavior of High Chromium White Cast Iron

    Institute of Scientific and Technical Information of China (English)

    SUN Zhi-ping; SHEN Bao-luo; WANG Jun; LIU Hao-huai; LUO Cheng

    2005-01-01

    The effect of manganese on the as-cast structure and hardening behavior of high chromium white cast iron subjected to sub-critical treatment was studied. The results indicate that the fraction of retained austenite and the manganese distribution in as-cast alloys are controlled by manganese content. The manganese distribution in as-cast alloys is not homogeneous. The manganese content in carbide is higher than that in matrix. Whether the secondary hardening occurs or not and the peak hardness of secondary hardening is controlled by manganese content in retained austenite in as-cast structure. Higher manganese content can cause more retained austenite. The secondary hardening occurs in sub-critical treating process if the fraction of retained austenite is high.

  9. Effect of Welding Mateial on Mechanical Working Properity of Gay Cast-iron by Cold Arc Welding%灰铸铁电弧冷焊时焊材对加工性能的影响

    Institute of Scientific and Technical Information of China (English)

    李日娟

    2011-01-01

    采用Z208、Z248、Z308、Z116四种焊条对灰铸铁进行电弧冷焊试验,对比了焊缝组织、半熔化区白口硬度及宽度,并从焊接冶金角度作出分析.结果表明:Z208 、Z248所焊焊缝同母材一样为灰铸铁,Z208因白口宽度大不能进行后续机加工;Z308、Z116所焊焊缝与母材异质,Z308几乎无白口,具有优良的加工性能.%The welding tests on Gay cast-iron were made with four kinds of electrode by cold arc welding(Z208 Z248 Z308 Zl 16), metallographic microstructure, the width and microhardness of the partial fusion were compared in welding metallurgy. The results show that the welded joint by Z208 and Z248 is same with base metal, the welded joint by Z208 are not matched; the welded joint by Z308 and Zl 16 is not same with the base metal, but the machining property is better.

  10. Optimization of Resin Infusion Processing for Composite Pipe Key-Part and K/T Type Joints Using Vacuum-Assisted Resin Transfer Molding

    Science.gov (United States)

    Wang, Changchun; Bai, Guanghui; Yue, Guangquan; Wang, Zhuxi; Li, Jin; Zhang, Boming

    2016-10-01

    In present study, the optimization injection processes for manufacturing the composite pipe key-part and K/T type joints in vacuum-assisted resin transfer molding (VARTM) were determined by estimating the filling time and flow front shape of four kinds of injection methods. Validity of the determined process was proved with the results of a scaling-down composite pipe key-part containing of the carbon fiber four axial fabrics and a steel core with a complex surface. In addition, an expanded-size composite pipe part was also produced to further estimate the effective of the determined injection process. Moreover, the resin injection method for producing the K/T type joints via VARTM was also optimized with the simulation method, and then manufactured on a special integrated mould by the determined injection process. The flow front pattern and filling time of the experiments show good agreement with that from simulation. Cross-section images of the cured composite pipe and K/T type joints parts prove the validity of the optimized injection process, which verify the efficiency of simulation method in obtaining a suitable injection process of VARTM.

  11. Optimization of Resin Infusion Processing for Composite Pipe Key-Part and K/T Type Joints Using Vacuum-Assisted Resin Transfer Molding

    Science.gov (United States)

    Wang, Changchun; Bai, Guanghui; Yue, Guangquan; Wang, Zhuxi; Li, Jin; Zhang, Boming

    2016-05-01

    In present study, the optimization injection processes for manufacturing the composite pipe key-part and K/T type joints in vacuum-assisted resin transfer molding (VARTM) were determined by estimating the filling time and flow front shape of four kinds of injection methods. Validity of the determined process was proved with the results of a scaling-down composite pipe key-part containing of the carbon fiber four axial fabrics and a steel core with a complex surface. In addition, an expanded-size composite pipe part was also produced to further estimate the effective of the determined injection process. Moreover, the resin injection method for producing the K/T type joints via VARTM was also optimized with the simulation method, and then manufactured on a special integrated mould by the determined injection process. The flow front pattern and filling time of the experiments show good agreement with that from simulation. Cross-section images of the cured composite pipe and K/T type joints parts prove the validity of the optimized injection process, which verify the efficiency of simulation method in obtaining a suitable injection process of VARTM.

  12. 49 CFR 192.113 - Longitudinal joint factor (E) for steel pipe.

    Science.gov (United States)

    2010-10-01

    ... resistance welded 1.00 Electric flash welded 1.00 Submerged arc welded 1.00 Furnace butt welded .60 Other... class Longitudinal joint factor (E) ASTM A 53/A53M Seamless 1.00 Electric resistance welded 1.00 Furnace....00 ASTM A 381 Double submerged arc welded 1.00 ASTM A 671 Electric-fusion-welded 1.00 ASTM A...

  13. Replacement of a defective ductile iron gas pipeline with d 500 PE 100 pipes; Austausch einer defekten GGG-Gasleitung durch PE 100-Rohre d 500

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Robert [FRIATEC Aktiengesellschaft, Mannheim (Germany)

    2010-05-15

    A 600 m long ductile cast-iron pipeline has been renewed safely, reliably and in record time in the center of the spa town of Bad Pyrmont. Following decades of positive experience, the local municipal utility placed its faith in PE 100 pipe material and resistance welding - a time-saving method of joining PE pipes which is also cost-efficient for large dimensions. (orig.)

  14. Properties and Microstructure of Laser Welded VM12-SHC Steel Pipes Joints

    Directory of Open Access Journals (Sweden)

    Skrzypczyk A.

    2016-06-01

    Full Text Available Paper presents results of microstructure and tests of welded joints of new generation VM12-SHC martensitic steel using high power CO2 laser (LBW method with bifocal welding head. VM12-SHC is dedicated to energetic installation material, designed to replace currently used. High content of chromium and others alloying elements improve its resistance and strength characteristic. Use of VM12-SHC steel for production of the superheaters, heating chambers and walls in steam boilers resulted in various weldability researches. In article are presented results of destructive and non-destructive tests. For destructive: static bending and Vickers hardness tests, and for non-destructive: VT, RT, UT, micro and macroscopic tests were performed.

  15. Tribology properties of composite layer of CrMoCu alloy cast iron by combined treatment of ion nitrocarburizing and sulphurizing

    Institute of Scientific and Technical Information of China (English)

    MA Shi-ning; HU Chun-hua; LI Xin; QIU Ji

    2004-01-01

    Composite layer with nitrocarbonide and sulfide was made on the surface of CrMoCu alloy cast iron by combined treatment of ion nitrocarburizing and sulphurizing. The composite layer is composed of sulfide layer, nitrocarbonide hypo-surface layer and its diffusing layer, the size of sulfide globular grains distributing equably on the surface is in nano-micron-scale, and the phase structure of the composite layer is composed of FeS, FeS1-x, Fe2C and Fe3N. Under oil lubrication, sulphurized surface shows good scuffing-resistance only under low velocity, and nitrocarburized and sulphurized surface greatly improves the scuffing-resistance and wear-resistance of CrMoCu alloy cast iron, its integrated friction and wear properties are better than those of the plain and sulphurized surfaces under all the velocities.

  16. Residual Stress, Structure and Other Properties Formation by Combined Thermo-Hardening Processing of Surface Layer of Gray Cast Iron Parts

    Science.gov (United States)

    Rakhimyanov, Kh M.; Nikitin, Yu V.; Semenova, Yu S.; Eremina, A. S.

    2016-04-01

    The proposed combined thermo-hardening processing of gray cast iron enables to control the surface layer structure and mechanical properties formation. The processing includes high-speed heating by low-temperature plasma source and ultrasonic surface plastic deformation. The algorithm of calculation the stress-strain state of a surface layer at combined processing of gray cast iron is developed. This algorithm is based on method of sections. The ultrasonic surface deformation contribution is determined during formation of residual stresses. It is established that the combination of the thermal and deformation effects on the material provides an additional increment of microhardness and increase of surface layer thickness. Experimental results shows that the features of structural and phase transformations in a surface layer are revealed without a surface melting by energy of low-temperature plasma. The top of a layer does not contain inclusions of graphite that testifies to change of structural transformations in conditions of combined processing.

  17. The influence of the graphite mechanical properties on the constitutive response of a ferritic ductile cast iron – A micromechanical FE analysis

    DEFF Research Database (Denmark)

    Andriollo, Tito; Thorborg, Jesper; Hattel, Jesper Henri

    2015-01-01

    In the present paper a micro-mechanical approach is used to investigate the influence of the graphite mechanical properties on the loading response in the early deformation range of ductile cast iron. A periodic unit cell composed by a single graphite nodule embedded in a uniform ferritic matrix...... is considered and elasto-plastic behavior of both constituents is assumed; damage evolution in the ductile matrix is taken into account via Lemaitre’s isotropic model. Full 3D and 2D plane-stress finite element analyses are performed to simulate the loading conditions experienced by nodules located in the bulk...... as well as on the material surface. The effects of residual stresses arising during the manufacturing process are also accounted for. It is shown that the constitutive response of the equivalent composite medium can match ductile cast iron only if the graphite Young’s modulus value lies within a certain...

  18. A methodology of appropriate weld procedures for axial compressive residual stress on inner surface in multi-pass girth welded pipe joint

    International Nuclear Information System (INIS)

    Weld residual stress and distortion, which often have negative influences on structural performance of welded components, should be controlled appropriately. Especially, weld residual stress in nuclear power plants can be one of the fatal problems as the factor in generation and propagation of stress corrosion cracking (SCC). It has become well known that an axial residual stress on the inner surface of welded pipe joint has a significant influence on SCC. The axial residual stress has been therefore controlled by additional process, such as some kinds of peening or heat treatment. On the other hand, another approaches for the in-process control of the axial residual stress during weld procedure should be also performed if it is technically possible. In this study, a parametric survey on the relationship between welding conditions, including configuration of the pipe joint, and weld residual stress is done by the numerical analysis with the thermal elastic-plastic model. Based on the numerical results, a methodology for controlling the axial residual stress on the inner surface of welded pipe joints is investigated from a viewpoint of the optimization of weld procedure. (author)

  19. Ductile PVC: a perfect pipe material; Schlagfestes PVC: Ein ausgezeichneter Rohrwerkstoff

    Energy Technology Data Exchange (ETDEWEB)

    Wolters, M.; Kop, L. [Gastec, Apeldoorn (Netherlands)

    2001-07-01

    Several pipe materials can be used for low-pressure gas distribution systems including steel, ductile and grey cast iron, asbestos cement, ductile (or high-impact) PVC and PE. Nowadays, the latter two are the most frequently applied materials. Plastics are generally advantageous in low-pressure distribution systems, in particular because of their resistance to soil corrosion and the relatively low overall costs. Remarkably, the Netherlands has opted mainly for ductile PVC, whereas PE is used almost exclusively in other countries. Yet ductile PVC has a number of major technical and economic benefits, which makes it worth considering for use in low-pressure gas distribution systems, such as a complete and sophisticated system, simple and reliable jointing techniques and low purchase and construction costs. (orig.) [German] Fuer Niederdruck-Gasverteilungssysteme gibt es eine Vielzahl von Rohrwerkstoffen, wie z.B. Stahl, Sphaeroguss, Grauguss, Asbestzement, PVC hart, schlagfestes PVC und PE. Die beiden letzten Werkstoffe werden heutzutage am haeufigsten verwendet. Kunststoffe sind bei Niederdrucksystemen in der Regel im Vorteil, insbesondere durch ihre Bestaendigkeit gegenueber Bodenkorrosion und die relativ niedrigen Gesamtkosten. Bemerkenswert ist, dass man sich in den Niederlanden vor allem fuer schlagfestes PVC und in anderen Laendern fast ausschliesslich fuer PE entschieden hat. Dennoch weist schlagfestes PVC einige wichtige technische und wirtschaftliche Vorteile auf, wodurch der Einsatz dieses Rohrwerkstoffes in Niederdruck-Gasverteilungssystemen erwaegenswert ist, darunter ein komplettes und ausgekluegeltes System, einfache und zuverlaessige Verbindungstechniken und niedrige Anschaffungs- und Verlegekosten. (orig.)

  20. Mechanical and Tribological Properties of HVOF-Sprayed (Cr3C2-NiCr+Ni) Composite Coating on Ductile Cast Iron

    Science.gov (United States)

    Ksiazek, Marzanna; Boron, Lukasz; Radecka, Marta; Richert, Maria; Tchorz, Adam

    2016-07-01

    The aim of the investigations was to compare the microstructure, mechanical, and wear properties of Cr3C2-NiCr+Ni and Cr3C2-NiCr coatings deposited by HVOF technique (the high-velocity oxygen fuel spray process) on ductile cast iron. The effect of nickel particles added to the chromium carbide coating on mechanical and wear behavior in the system of Cr 3 C 2 -NiCr+Ni/ductile cast iron was analyzed in order to improve the lifetime of coated materials. The structure with particular emphasis of characteristic of the interface in the system of composite coating (Cr 3 C 2 -NiCr+Ni)/ductile cast iron was studied using the optical, scanning, and transmission electron microscopes, as well as the analysis of chemical and phase composition in microareas. Experimental results show that HVOF-sprayed Cr3C2-NiCr+Ni composite coating exhibits low porosity, high hardness, dense structure with large, partially molten Ni particles and very fine Cr3C2 and Cr7C3 particles embedded in NiCr alloy matrix, coming to the size of nanocrystalline. The results were discussed in reference to examination of bending strength considering cracking and delamination in the system of composite coating (Cr 3 C 2 -NiCr+Ni)/ductile cast iron as well as hardness and wear resistance of the coating. The composite structure of the coating provides the relatively good plasticity of the coating, which in turn has a positive effect on the adhesion of coating to the substrate and cohesion of the composite coating (Cr3C2-NiCr+Ni) in wear conditions.

  1. Effects of the Exposure to Corrosive Salts on the Frictional Behavior of Gray Cast Iron and a Titanium-Based Metal Matrix Composite

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL; Truhan, Jr., John J [ORNL; Kenik, Edward A [ORNL

    2007-01-01

    The introduction of increasingly aggressive road-deicing chemicals has created significant and costly corrosion problems for the trucking industry. From a tribological perspective, corrosion of the sliding surfaces of brakes after exposure to road salts can create oxide scales on the surfaces that affect friction. This paper describes experiments on the effects of exposure to sodium chloride and magnesium chloride sprays on the transient frictional behavior of cast iron and a titanium-based composite sliding against a commercial brake lining material. Corrosion scales on cast iron initially act as abrasive third-bodies, then they become crushed, spread out, and behave as a solid lubricant. The composition and subsurface microstructures of the corrosion products on the cast iron were analyzed. Owing to its greater corrosion resistance, the titanium composite remained scale-free and its frictional response was markedly different. No corrosion scales were formed on the titanium composite after aggressive exposure to salts; however, a reduction in friction was still observed. Unlike the crystalline sodium chloride deposits that tended to remain dry, hygroscopic magnesium chloride deposits absorbed ambient moisture from the air, liquefied, and retained a persistent lubricating effect on the titanium surfaces.

  2. Study on Friction and Wear Characteristics and Structure of Compound Layer from Combined Treatment of Ion Nitrocarburizing-Ion Sulphurizing of CrMoCu Alloy Cast Iron

    Institute of Scientific and Technical Information of China (English)

    MA Shi-ning; HU Chun-hua; LI Xin; QIU Ji

    2004-01-01

    The technics of combined treatment of ion nitrocarburizing-ion sulphurizing of CrMoCu alloy cast iron has been investigated and the compound layer with nitrocarbonide and sulphide has been made on the surface of CrMoCu alloy cast iron. The compound layer is composed of sulfide surface layer and the nitrocarbonide hypo-surface layer and its diffusing layer. The size of sulfide globular grains distributing equably on the surface is in nano-micron-scale, and the phase structure of the compound layer is composed of FeS、 FeS2、 Fe2C and Fe3N. Under dry sliding condition, the friction-reducing of sulphurized surface is good, but its function time can't last very long. The nitrocarbonided+sulphurized surface can greatly improve the wear-resistance and the friction-reducing of CrMoCu alloy cast iron, and its integrated friction and wear properties are better than plain and sulphurized surfaces'.

  3. Study on Friction and Wear Characteristics and Structure of Compound Layer from Combined Treatment of Ion Nitrocarburizing-Ion Sulphurizing of CrMoCu Alloy Cast Iron

    Institute of Scientific and Technical Information of China (English)

    MAShi-ning; HUChun-hua; LIXin; QIUJi

    2004-01-01

    The technics of combined treatment of ion nitrocarburizing-ion sulpburizing of CrMoCu alloy cast iron has been investigated and the compound layer with nitrocabonide and sulphide has been made on the surface of CrMoCu alloy cast iron. The compound layer is composed of sulfide surface layer and the nitrocarbonide hypo-surface layer and its diffusing laye. The size of sulfide globular grains distributing equably on the surface is in nano-micmn-scale, and the phase structure of the compound layer is composed of FeS, FeS2, Fe2C and FerN. Under dry sliding condition, the friction-reducing of sulphurized surface is good, but its function time can't last vet3. long, The nitrocarbonided+sulphurized surface can gready improve the wear-resistance and the friction-reducing of CrMoCu alloy cast iron, and its integrated friction and wear properties are better than plain and sulphurized surfaces.

  4. Electron theory study on the effect of Mn on as-cast structure of Fe-C-Cr-Mn cast irons

    Institute of Scientific and Technical Information of China (English)

    SUN Zhi-ping; SHEN Bao-luo; WANG Jun; LIU Hao-huai; YANG Hong-shan; HUANG Si-jiu

    2008-01-01

    The valence electron structure of alloying austenite of 3C-15Cr high chromium White cast iron with different Mn contents from 1%to 6% is analyzed by BLD method and EET.Results shoW that the addition of Mn has major influence on the valence electron structure of the alloying austenite,especially on that of Fe-C,Fe-C-Cr and Fe-C-Cr-Mn unit cells of it.The effect becomes weak when Mn content is over 4%.Based on the effect of nA,F Dc,the weighting of each unit cell and the degree of underceoling on phase transition of the austenite,we can calculate the retained austenite content of as-cast structure of the hish chromium white cast iron.The calculation results coincide well with those of the experiment.The phase transition characters of the austenite in high chromium white cast iron can be forecasted through valence electron structure analysis of alloying austenite by BLD method and EET on the basis of Fe-C-Cr equilibrium phase diagram.

  5. Fabrication of plain carbon steel/high chromium white cast iron bimetal by a liquid-solid composite casting process

    Institute of Scientific and Technical Information of China (English)

    V Javaheri; H Rastegari; M Naseri

    2015-01-01

    High-chromium white cast iron (HCWCI) is one of the most widely used engineering materials in the mining and cement indus-tries. However, in some components, such as the pulverizer plates of ash mills, the poor machinability of HCWCI creates difficulties. The bimetal casting technique is a suitable method for improving the machinability of HCWCI by joining an easily machined layer of plain car-bon steel (PCS) to its hard part. In this study, the possibility of PCS/HCWCI bimetal casting was investigated using sand casting. The inves-tigation was conducted by optical and electron microscopy and non-destructive, impact toughness, and tensile tests. The hardness and chemical composition profiles on both sides of the interface were plotted in this study. The results indicated that a conventional and low-cost casting technique could be a reliable method for producing PCS/HCWCI bimetal. The interfacial microstructure comprised two distinct lay-ers:a very fine, partially spheroidized pearlite layer and a coarse full pearlite layer. Moreover, characterization of the microstructure revealed that the interface was free of defects.

  6. Effects of different inoculants on the microstructural characteristics of gray cast iron gg-25, hardness and useful life of tools

    Directory of Open Access Journals (Sweden)

    Diego Ruben Martin

    2015-10-01

    Full Text Available Current study evaluated the machinability characteristics of parts, microstructure and mechanical properties when three different inoculants (IM-22 with FeSi-Ba/Zr; G-20 and FeSi-Ba; IMSR 75 with FeSi-Sr were added in experiments carried out in a foundry. The research methodology was mailly based on the analysis of the machinability by the milling process of the specimens in gray cast iron GG-25, name according to DIN EN 1561.Evaluation of results is based on a thorough analysis of tool wear, surface finish, microstructural analysis, chemical composition and mechanical properties of the material. Results showed that among the studied inoculants strontium sulfide (SrS was thermodynamically more stable than the others, because it leds towards a more negative free energy change of Gibbs and therefore more favorable to the formation of nuclei having greater critical radius (rc, solidification with heterogeneous nucleation. Its inoculant was also more efficient in forming a more favorable microstructure, greater amounts of eutectic cells and, longer life of the insert when machined.

  7. Wear and Corrosion Resistance of Fe Based Coatings by HVOF Sprayed on Gray Cast-Iron for Automotive Application

    Directory of Open Access Journals (Sweden)

    M.S. Priyan

    2014-12-01

    Full Text Available In this study, commercially available FeSiNiCr and FeBCr alloy powders were designed with suitable compositions, gas atomized and then coated on gray cast-iron substrate. The microstructures of the feed stock Fe based alloy powders and the coatings were investigated by means of optical microscopy (OM, X-Ray diffraction (XRD, Thermogravimetric analysis (TGA and Scanning Electron Microscopy (SEM. In the present study, both the coating materials experienced two-body wear mechanisms. The results showed that for loads of 0.05 N, 0.1 N and 0.2 N, the wear resistance of FeBCr coating was less than FeSiNiCr by 44 %, 40 % and 31 %, respectively. The results indicated that the coated substrates exhibited lower corrosion current densities and lower corrosion rates, when placed in 20 wt.% H2SO4 solutions. In addition, the use of optimal spraying parameters/conditions gave improvements to the corrosion resistance of the substrates that had been treated with the crystalline coating.

  8. Emission of organic compounds from mould and core binders used for casting iron, aluminium and bronze in sand moulds.

    Science.gov (United States)

    Tiedje, Niels; Crepaz, Rudolf; Eggert, Torben; Bey, Niki

    2010-12-01

    Emissions from mould and core sand binders commonly used in the foundry industry have been investigated. Degradation of three different types of binders was investigated: Furfuryl alcohol (FA), phenolic urethane (PU) and resol-CO2 (RC). In each group of binders, at least two different binder compositions were tested. A test method that provides uniform test conditions is described. The method can be used as a general test method to analyse off gases from binders. Moulds, containing a standard size casting, were produced and the amount and type of organic compounds, resulting from thermal degradation of binders, was monitored when cast iron, bronze and aluminium was poured in the moulds. Binder degradation was measured by collecting off gases in a specially designed ventilation hood at a constant flow rate. Samples were taken from the ventilation system and analysed for hydrocarbons and CO content. It is shown how off-gases vary with time after pouring and shake out. Also the composition of off-gases is analysed and shown. It is further shown how the composition of off-gasses varies between different types of binders and with varying composition of the binders as well as function of the thermal load on the moulding sand. PMID:20954042

  9. Nb在灰铸铁中的存在形态%Existing Morphologies of Niobium in Cast Irons

    Institute of Scientific and Technical Information of China (English)

    朱洪波; 孙小亮; 闫永生; 华勤; 翟启杰

    2011-01-01

    The existing morphologies of niobium in cast irons were mvestigated by using SEM with spectroscopy. The result showed that only a little quantity of niobium dissolved as the atom type in the matrix and formed solid solution.however most of the niobium formed the Nb-rich phase embedding into the matrix;the Nb-rich phase had a lots of morphologies such as the clump shape (including square and triangle shape),abnormal shape (including Ⅹ type and Ⅴ type).and bar shape. TiN could act as the heterogeneous crystal nucleus in the forming process of the Nb-rich phase and,therefore,it had the effect to promote the formation of the Nb-rich phase.%用附带能谱的扫描电镜研究了Nb在灰铸铁中的存在形态,结果显示:少量Nb以原子形式固溶于基体,绝大多数Nb形成富Nb相镶嵌在基体上面;富Nb相形态丰富,有块状(包括方块状和_一角形)、不规则形状(包括X型、Y型)以及条棒状;在富Nb相形成过程中,TiN可能作为异质核心,因而对富Nb相的形成起了促进作用.

  10. EFFECT OF TOOL NOSE RADIUS AND CUTTING PARAMETERS ON TOOL LIFE, SURFACE ROUGHNESS IN TURNING OF GREY CAST IRON

    Directory of Open Access Journals (Sweden)

    Prasanna P Kulkarni

    2014-03-01

    Full Text Available In metal cutting industries peoples are trying to reduce the cost of the production by proper selection of inserts, tool geometry, and cutting conditions to obtain economical benefits. Tool nose radius has significant influence on tool life and surface finish. The aim of this research is to investigate the effect of tool nose radius under different cutting conditions and their effect on tool life, surface roughness. The measurement has been carried out by rough boring operation using grey cast iron cylinder liners at three cutting speed (Vc and feed rate (f. Depth of cut (doc is kept constant at 2.5mm.Cutting tool used in this work is multilayer coated tool of nose radius 0.8mm and 1.2mm nose radius. Tool coated with titanium nitride (TiN + titanium carbo nitride (TiCN +Aluminium oxide (Al2O3 coating. The insert is designated with SNMG 120408. Cutting conditions used is speed (Vc 100m/min, 125m/min and 150m/min. Feed rate (f 0.20mm/rev,0.23mm/rev,0.27mm/rev.Finally results of the present work determine the appropriate parameter for increasing the tool life and surface finish for two different nose radius tools.

  11. EXPERIMENTAL INVESTIGATION OF EROSIVE WEAR ON THE HIGH CHROME CAST IRON IMPELLER OF SLURRY DISPOSAL PUMP USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Jasbir Singh Ratol

    2012-07-01

    Full Text Available Erosive wear occurs on the impeller and volute casing of the slurry disposal pump due to the impact of the ash particles on the impeller with a high velocity. Due to erosive wear, pump life become very short. The service life of centrifugal pump, handling slurry can be increased by reducing the erosive wear. In the present work, the experimental investigation of erosive wear has been carried out on the high speed slurry erosion tester to understand the effects of the ash concentration in slurry, rotational speed of the pump impeller and ash particle size on erosive wear. The erosive wear behaviour of high chrome cast iron was investigated by Response surface methodology (RSM. Analysis of variance (ANOVA was used for statistical analysis and the modeled values for the response were obtained with the help of modeled equation. The result shows that the ash concentration in slurry and kinetic energy of the moving particles highly contributes to erosive wear of pump impeller as compared to the ash particle size.

  12. Experimental Investigation of Erosive Wear on the High Chrome Cast Iron Impeller of Slurry Disposal Pump Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2012-05-01

    Full Text Available Erosive wear occurs on the impeller and volute casing of the slurry disposal pump due to the impact of the ash particles on the impeller with a high velocity. Due to erosive wear, pump life become very short. The service life of centrifugal pump, handling slurry can be increased by reducing the erosive wear. In the present work, the experimental investigation of erosive wear has been carried out on the high speed slurry erosion tester to understand the effects of the ash concentration in slurry, rotational speed of the pump impeller and ash particle size on erosive wear. The erosive wear behavior of high chrome cast iron was investigated by Response surface methodology (RSM. Analysis of variance (ANOVA was used for statistical analysis and the modeled values for the response were obtained with the help of modeled equation. The result shows that the ash concentration in slurry and kinetic energy of the moving particles highly contributes to erosive wear of pump impeller as compared to the ash particle size.

  13. Study on fragmentation and dissolution behavior of carbide in a hot-rolled hypereutectic high chromium cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fei; Jiang, Yehua, E-mail: jiangyehua@kmust.edu.cn; Xiao, Han; Tan, Jun

    2015-01-05

    Highlights: • The method to prepare Carbon steel/High chromium iron is totally new. • High chromium iron can achieve small plastic deformation during hot rolling process. • Carbides in high chromium irons are crushed, refined obviously and becoming isolated, which is benefit to improve the impact toughness. • The carbide fragmentation and dissolution behavior of the hot-rolled HCCI were analyzed. - Abstract: A sandwich-structured composite containing a hypereutectic high chromium cast iron (HCCI) and low carbon steel (LCS) claddings was newly fabricated by centrifugal casting, then the blank was hot-rolled into composite plate. The carbide fragmentation and dissolution behavior of the hot-rolled HCCI were analyzed. During hot rolling, significant refinement of carbides was discovered in hot-rolled HCCI specimens. The carbides were broken and partly dissolved into the austenite matrix. The results show that carbides are firstly dissolved under the action of stress. There are grooves appeared at the boundaries of the carbides. The grooves reduce the cross section of the carbide. When the cross section of the carbide reaches to the required minimum critical cross section, the carbide breaks through the tensile force. After break, carbides continue to dissolve since more interfaces between the matrix and carbides are generated. The secondary carbides precipitated due to the dissolution are index as fcc and stacking faults parallel to the {1 1 1} are observed.

  14. Control of Carbides and Graphite in Cast Irons Type Alloy’s Microstructures for Hot Strip Mills

    Directory of Open Access Journals (Sweden)

    Sergio Villanueva Bravo

    2012-01-01

    Full Text Available The carbide and graphite formation and redistribution of alloy elements during solidification were investigated on high-speed steel (HS and Ni-hard type cast irons with Nb and V. The crystallization of hypereutectic HSS proceeds in the order of primary MC, γ + MC, γ + M6C, γ + M7C3, and γ +  graphite eutectic, in hypoeutectic alloys proceeds in the order of primary γ, γ + MC, γ + graphite, γ + M6C, and γ + M7C3 eutectic, and in Ni-hard proceeds in the order of primary γ, γ + MC, γ + M3C, and γ +  graphite eutectic. The γ +  graphite eutectic solidifies with the decrease of V, Nb, and Cr and the increase of Si and C contents in residual liquid during solidification. The behavior in graphite forming tendency in the residual liquid is estimated by the parameter ∑CLimi′. The eutectic graphite crystallizes at the solid fraction when ∑CLimi′ takes a minimum value. The amount of graphite increases with the decrease in ∑CLimi′ of initial alloy content in both specimens. Inoculation with ferrosilicon effectively increases the graphite content in both specimens.

  15. Effect of medium on friction and wear properties of compacted graphite cast iron processed by biomimetic coupling laser remelting process

    International Nuclear Information System (INIS)

    Stimulated by the cuticles of soil animals, an attempt to improve the wear resistance of compact graphite cast iron (CGI) with biomimetic units on the surface was made by using a biomimetic coupled laser remelting process in air and various thicknesses water film, respectively. The microstructures of biomimetic units were examined by scanning electron microscope and X-ray diffraction was used to describe the microstructure and identify the phases in the melted zone. Microhardness was measured and the wear behaviors of biomimetic specimens as functions of different mediums as well as various water film thicknesses were investigated under dry sliding condition, respectively. The results indicated that the microstructure zones in the biomimetic specimens processed with water film are refined compared with that processed in air and had better wear resistance increased by 60%, the microhardness of biomimetic units has been improved significantly. The application of water film provided finer microstructures and much more regular grain shape in biomimetic units, which played a key role in improving the friction properties and wear resistance of CGI.

  16. Effect of scanning speed during PTA remelting treatment on the microstructure and wear resistance of nodular cast iron

    Institute of Scientific and Technical Information of China (English)

    Hua-tang Cao; Xuan-pu Dong; Qi-wen Huang; Zhang Pan; Jian-jun Li; Zi-tian Fan

    2014-01-01

    The surface of nodular cast iron (NCI) with a ferrite substrate was rapidly remelted and solidified by plasma transferred arc (PTA) to induce a chilled structure with high hardness and favorable wear resistance. The effect of scanning speed on the microstructure, micro-hardness distribution, and wear properties of PTA-remelted specimens was systematically investigated. Microstructural characterization in-dicated that the PTA remelting treatment could dissolve most graphite nodules and that the crystallized primary austenite dendrites were transformed into cementite, martensite, an interdendritic network of ledeburite eutectic, and certain residual austenite during rapid solidifica-tion. The dimensions of the remelted zone and its dendrites increase with decreased scanning speed. The microhardness of the remelted zone varied in the range of 650 HV0.2 to 820 HV0.2, which is approximately 2.3-3.1 times higher than the hardness of the substrate. The wear re-sistance of NCI was also significantly improved after the PTA remelting treatment.

  17. Damage Analysis of a Ferritic SiMo Ductile Cast Iron Submitted to Tension and Compression Loadings in Temperature

    Directory of Open Access Journals (Sweden)

    Isabel Hervas

    2015-12-01

    Full Text Available Tensile and compression tests were carried out on a ductile cast iron for temperatures up to 1073 K. The damage caused inside and around graphite nodules was evaluated as a function of the local equivalent plastic strain by using microstructural quantifications. The mechanical properties are strongly dependent on a temperature above 773 K. Concerning tensile behavior, an evolutional law issued from the Gurson model representing the void growth as a function of the deformation and temperature was successfully employed. It is demonstrated that the strain state and the temperature have a strong influence on the void growth function. In the case of compression tests, the temperature has a weak influence on the nodule deformation for temperatures lower than 773 K, and the mechanical behavior is driven by the viscoplastic properties of the ferrite. For higher temperatures, the mechanical properties in compression are progressively modified, since graphite nodules tend to remain spherical, and ferrite grains are severely deformed. A synthesis of the damage mechanisms is proposed in the studied range of temperature and plastic strain. It appears that the graphite nodule aspect ratio can be used as an indicator of the deformation under compression loading for temperatures ranging from room temperature to 673 K.

  18. Effect of electrical pulse treatment on the thermal fatigue resistance of bionic compacted graphite cast iron processed in water

    International Nuclear Information System (INIS)

    Highlights: ► Electrical pulse treatment can reduce cracks on bionic units before thermal fatigue tests. ► Electrical pulse treatment can reduce crack sources during thermal fatigue tests. ► Thermal fatigue resistance of bionic units processed in water is enhanced. ► Thermal fatigue resistance of bionic CGI processed in water is improved. -- Abstract: In order to further enhance the thermal fatigue resistance of bionic compacted graphite cast iron (CGI) which is processed by laser in water, the electrical pulse treatment is applied to improve the thermal fatigue resistance of bionic units. The results show that the electrical pulse treatment causes the supersaturated carbon atoms located in the lattice of austenite to react with the iron atoms to form the Fe3C. The microstructures of the bionic units processed in water are refined by the electrical pulse treatment. The cracks on the bionic units are reduced by the electrical pulse treatment before the thermal fatigue tests; and during the tests, the thermal fatigue resistance of bionic units is therefore enhanced by reducing the crack sources. By this way, the thermal fatigue resistance of bionic CGI processed in water is improved.

  19. Effect of thermal fatigue on the wear resistance of graphite cast iron with bionic units processed by laser cladding WC

    Science.gov (United States)

    Jing, Zhengjun; Zhou, Hong; Zhang, Peng; Wang, Chuanwei; Meng, Chao; Cong, Dalong

    2013-04-01

    Thermal fatigue and wear exist simultaneously during the service life of brake discs. Previous researchers only studied thermal fatigue resistance or abrasion resistance of compact graphite cast iron (CGI), rather than combining them together. In this paper, wear resistance after thermal fatigue of CGI was investigated basing on the principle of bionics, which was close to actual service condition of the brake discs. In the meanwhile, the effect of thermal fatigue on wear resistance was also discussed. Non-smooth bionic units were fabricated by laser cladding WC powder with different proportions (50 wt.%, 60 wt.%, 70 wt.%). Microstructure and microhardness of the units were investigated, and wear mass losses of the samples were also compared. The results indicate that thermal fatigue has a negative effect on the wear resistance. After the same thermal fatigue cycles times, the wear resistance of laser cladding WC samples is superior to that of laser remelting ones and their wear resistance enhances with the increase of WC content.

  20. Effects of bionic units on the fatigue wear of gray cast iron surface with different shapes and distributions

    Science.gov (United States)

    Chen, Zhi-kai; Lu, Shu-chao; Song, Xi-bin; Zhang, Haifeng; Yang, Wan-shi; Zhou, Hong

    2015-03-01

    To improve the fatigue wear resistance of gray cast iron (GCI), GCI samples were modified by a laser to imitate the unique structure of some soil animals alternating between soft and hard phases; the hard phase resists the deformation and the soft phase releases the deformation. Using the self-controlled fatigue wear test method, the fatigue wear behaviors of treated and untreated samples were investigated and compared experimentally. The results show that the bionic non-smooth surface obtains a beneficial effect on improving the fatigue wear resistance of a sample, and the fatigue wear resistance of the bionic sample assembled with reticulate units (60°+0°), whose mass loss was reduced by 62%, was superior to the others. Meanwhile, a finite element (FE) was used to simulate the compression and the distributions of strain and stress on the non-smooth surface was inferred. From these results, we understood that the functions of the bionic unit such as reducing strain and stress, and also obstructing the closure and propagation of cracks were the main reasons for improving the fatigue wear property of GCI.

  1. Influence of Orientations of Bionic Unit Fabricated by Laser Remelting on Fatigue Wear Resistance of Gray Cast Iron

    Science.gov (United States)

    Chen, Zhi-Kai; Zhou, Ti; Zhang, Hai-feng; Yang, Wan-shi; Zhou, Hong

    2015-06-01

    Fatigue wear resistance improvements were researched by studying experimental samples with gray cast iron fabricated with bionic units in different orientations. Experimental samples were modified by laser surface remelting, including parallel, vertical, and gradient units to the wear direction. The remelting pool was then studied to determine the micro-hardness, microstructure, alteration of phase, and etc. Lab-control fatigue wear test method was applied with the treated and untreated samples tested under the laboratorial conditions. Wear resistance result was considered as the rolling contact fatigue (RCF) resistance and mechanisms of the modified samples were experimentally investigated and discussed. Results suggested that all treated samples demonstrated the beneficial effect on the RCF improvement due to lack of graphite and reinforcement of treated region. Results also indicated the sample with fastigiated units was more effective than that with vertical units or parallel units to the wear direction. Influence of the sample unit's angle which intensely depended on the conditions of actual application, however, was not identified.

  2. Evaluation of Surface Roughness and Power Consumption in Machining FCD 450 Cast Iron using Coated and Uncoated Irregular Milling Tools

    Science.gov (United States)

    Razlan Yusoff, Ahmad; Arsyad, Fitriyanti

    2016-02-01

    In this project, the effects of different cutting parameters on surface roughness and power consumption when machining FCD450 cast iron were studied using coated and uncoated irregular milling tool geometry of variable helix and pitch. Their responses on roughness and power consumption were evaluated based on the spindle speed, feed rate, and depth of cut, machining length and machining time. Results showed that except spindle speed and machining length, other parameters such as feed rate, axial and radial depth of cut and also machining time proportionate with surface roughness. The power consumption proportionately increase for all cutting parameters except feedrate. It is showed that the average decrement 27.92 percent for surface roughness and average decrement 9.32 percent for power consumption by using coated compared to uncoated tool. Optimum cutting parameters for both minimum surface roughness and power consumption can be determined. The coated tools performed better than uncoated milling tools for responses of surface roughness and power consumption to increase machining productivity and profit.

  3. Effect of Slope Plate Variable and Reheating on the Semi-Solid Structure of Ductile Cast Iron

    Institute of Scientific and Technical Information of China (English)

    M. Nili-Ahmadabadi; F. Pahlevani; P. Babaghorbani

    2008-01-01

    Semi-solid metal casting and forming is a promising production method for a wide range of metal alloys. In spite of many applications for semi-solid processed light alloys, few works have reported on the semi-solid processing of iron and steel. In this research, an inclined plate was used to change the dendritic structure of iron to globular. The effects of the length and slope of the plate on the casting structure were examined. The results show that the process effectively changes the dendritic structure to globular. A sloped plate angle of 7.5° and length of 560 mm with a cooling rate of 67 K·s-1 gave the optimum graphite nodu-larity and solid particle globularity. The results also show that the sloped plate more easily prevents inocu-lant fading since the total time processing is rather short. In addition the semi-solid ductile cast iron prepared using the inclined plate method was reheated to examine the effect of reheating conditions on the micro-structure and coarsening kinetics of the alloy. The solid fractions at different reheating temperatures and holding times were used to find the optimum reheating temperature range.

  4. Microstructure and Wear Behavior of TiC Coating Deposited on Spheroidized Graphite Cast Iron Using Laser Surfacing

    Directory of Open Access Journals (Sweden)

    E. R. I. Mahmoud

    2014-10-01

    Full Text Available Spheroidal graphite cast iron was laser cladded with TiC powder using a YAG fiber laser at powers of 700, 1000, 1500 and 2000 W. The powder was preplaced on the surface of the specimens with 0.5 mm thickness. Sound cladding and fusion zones were observed at 700, 1000 and 1500 W powers. However, at 2000 W, cracking was observed in the fusion zone. At 700 W, a build-up zone consisted of fine TiC dendrites inside a matrix composed of martensite, cementite (Fe3C, and some blocks of retained austenite was observed. In this zone, all graphite nodules were totally melted. In the fusion zone, some undissolved and partially dissolved graphite nodules appeared in a matrix containing bainite, ferrite, martensite and retained austenite. At 1500 W, the fusion zone had more iron carbides and ferrite, and the HAZ consisted of martensitic structure. At 2000 W, the build-up zone was consisted of TiC particles precipitated in a matrix of eutectic carbides, martensite plus an inter-lamellar retained austenite. The hardness of the cladded area was remarkably improved (1330 HV in case of 700 W: 5.5 times of the hardness of substrate

  5. 49 CFR 192.281 - Plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion..., see § 192.7). (3) The joint may not be heated to accelerate the setting of the cement. (c) Heat-fusion joints. Each heat-fusion joint on plastic pipe must comply with the following: (1) A butt...

  6. Combination of microscopic model and VoF-multiphase approach for numerical simulation of nodular cast iron solidification

    Science.gov (United States)

    Subasic, E.; Huang, C.; Jakumeit, J.; Hediger, F.

    2015-06-01

    The ongoing increase in the size and capacity of state-of-the-art wind power plants is highlighting the need to reduce the weight of critical components, such as hubs, main shaft bearing housings, gear box housings and support bases. These components are manufactured as nodular iron castings (spheroid graphite iron, or SGI). A weight reduction of up to 20% is achievable by optimizing the geometry to minimize volume, thus enabling significant downsizing of wind power plants. One method for enhancing quality control in the production of thick-walled SGI castings, and thus reducing tolerances and, consequently, enabling castings of smaller volume is via a casting simulation of mould filling and solidification based on a combination of microscopic model and VoF-multiphase approach. Coupled fluid flow with heat transport and phase transformation kinetics during solidification is described by partial differential equations and solved using the finite volume method. The flow of multiple phases is described using a volume of fluid approach. Mass conservation equations are solved separately for both liquid and solid phases. At the micro-level, the diffusion-controlled growth model for grey iron eutectic grains by Wetterfall et al. is combined with a growth model for white iron eutectic grains. The micro-solidification model is coupled with macro-transport equations via source terms in the energy and continuity equations. As a first step the methodology was applied to a simple geometry to investigate the impact of mould-filling on the grey-to-white transition prediction in nodular cast iron.

  7. Influence on SAWH Pipe Quality of Forming Joint Close%成型合缝对螺旋埋弧焊管质量的影响

    Institute of Scientific and Technical Information of China (English)

    毛浓召; 乔凌云; 张继成

    2013-01-01

    The welding quality of SAWH pipe and the quality of forming joint close are inseparable,poor forming joint close will cause some welding defects,such as gas pocket,slag inclusion,deviation etc. In this article,it briefly introduced SAWH pipe forming process and ideal forming joint close conditions. Combined with process,it analyzed forming reason,the effect on welding procedure,forming process and distribution characteristics of 3 kinds of abnormal forming joint close,including abnormal gap, dislocation and asymmetry. It also gave corresponding control and prevention measures. During production course,it should strictly control each working procedure to ensure uniform and stable forming joint close,and provide good process conditions for welding.%螺旋埋弧焊管焊接质量与成型合缝质量密不可分,成型合缝控制不好会产生气孔、夹渣、焊偏等焊接缺陷。简要介绍了螺旋埋弧焊管成型工艺及理想的成型合缝的条件。结合生产工艺,分析了间隙异常、错位和非对称3种异常合缝产生的原因、对焊接过程的影响以及异常合缝的形成过程及分布特点,并结合生产经验给出了相应的控制预防措施。在焊管生产过程中,应严格控制每一道工序,确保成型合缝均匀、稳定,为焊接提供良好的工艺条件。

  8. Atmospheric corrosion rate expressed as a function of time. Effects of atmospheric conditions and alloying elements on corrosion resistance of steels and cast irons

    International Nuclear Information System (INIS)

    On the basis of function describing a change in atmospheric corrosion rate (K) in time (t) the published results of long-standing corrosion tests of a great number of cast irons and steels were statistically processed. The effect of chloride - ions, sulfur dioxide, alloying elements (Cu, Ni, Cr, Mn, Si, V, C) on the rate of initial corrosion on the active surface (K0), passivation properties (α0) of corrosion products and corrosion resistance (α0/K0) of iron-carbonic alloys in different climatic areas was revealed. The data permit further investigation of the mechanism of alloying element effect on atmopsheric corrosion of steels

  9. The effects of novel surface treatments on the wear and fatigue properties of steel and chilled cast iron

    Science.gov (United States)

    Carroll, Jason William

    Contact fatigue driven wear is a principal design concern for gear and camshaft engineering of power systems. To better understand how to engineer contact fatigue resistant surfaces, the effects of electroless nickel and hydrogenated diamond-like-carbon (DLC) coatings on the fatigue life at 108 cycles of SAE 52100 steel were studied using ultrasonic fatigue methods. The addition of DLC and electroless nickel coatings to SAE 52100 bearing steel had no effect on the fatigue life. Different inclusion types were found to affect the stress intensity value beyond just the inclusion size, as theorized by Murakami. The difference in stress intensity values necessary to propagate a crack for Ti (C,N) and alumina inclusions was due to the higher driving force for crack extension at the Ti (C,N) inclusions and was attributed to differences in the shape of the inclusion: rhombohedral for the Ti (C,N) versus spherical for the oxides. A correction factor was added to the Murakami equation to account for inclusion type. The wear properties of DLC coated SAE 52100 and chilled cast iron were studied using pin-on-disk tribometry and very high cycle ultrasonic tribometry. A wear model that includes sliding thermal effects as well as thermodynamics consistent with the wear mechanism for DLCs was developed based on empirical results from ultrasonic wear testing to 108 cycles. The model fit both ultrasonic and classic tribometer data for wear of DLCs. Finally, the wear properties of laser hardened steels - SAE 8620, 4140, and 52100 - were studied at high contact pressures and low numbers of cycles. A design of experiments was conducted to understand how the laser processing parameters of power, speed, and beam size, as well as carbon content of the steel, affected surface hardness. A hardness maximum was found at approximately 0.7 wt% carbon most likely resulting from increased amounts of retained austenite. The ratcheting contact fatigue model of Kapoor was found to be useful in

  10. Heating coil welding technique for connection of large-diameter PE pipes using universally applicable, flexible taped joints; Heizwendelschweissverfahren fuer die Verbindung von PE-Grossrohren mittels universal anwendbarer, flexibler Wickelmuffen

    Energy Technology Data Exchange (ETDEWEB)

    Baudrit, Benjamin; Kraus, Eduard; Heidemeyer, Peter; Bastian, Martin [Sueddeutsche Kunststoff-Zentrum, Wuerzburg (Germany); Kern, Juergen; Neufeld, Wjatscheslaw [Frank und Krah Wickelrohr GmbH, Woelfersheim (Germany)

    2011-07-01

    This research project (Heating coil welding technique for connection of large-diameter PE pipes using universally applicable, flexible taped joints) was carried out by SKZ (Sueddeutsches Kunststoff-Zentrum) in close coopearation with Messrs. Frank and Krah Wickelrohr GmbH with the intention to develop a high-quality, economically efficient joining process for large-diameter pipes. The technique is based on the new technology of heating coil joints which permits the use of any desired joint geometries at acceptable cost. The new technique was validated for joints up to a diameter of 1,000 mm. With the welding parameters calculated in the project, even larger diameter joints are possible in theory.

  11. Cast iron promises.

    Science.gov (United States)

    Hawker, Andrew

    2007-01-01

    During the Victorian era, a fiercely competitive industry emerged to build and operate Britain's railways. Many of the design and construction skills required were still fairly rudimentary, and were typically developed through practical experience. The resulting mix of entrepreneurship and new technology reshaped the landscape, but often in ways which proved hazardous for passengers. Minor accidents were commonplace, and a number of major failures occurred, one such being the collapse of the Tay Bridge, in 1879. Events in the ten years prior to this disaster still have some resonance today. Ambitions to exploit new technology are not always matched by foresight in the planning, financing or management of projects. Contracts may be based on wrong assumptions, and prove difficult to enforce. Once a project has gathered momentum, those working on it may fear that any attempt to draw attention to risks or defects will be seen as disloyal. When work is completed, it cannot be assumed that formal inspections will reveal potential flaws, or that those using the technology will appreciate the need to follow the procedures laid down for them. Some possible parallels with recent experiences in NHS computing are noted. PMID:18005560

  12. Cast iron promises

    Directory of Open Access Journals (Sweden)

    Andrew Hawker

    2007-09-01

    Events in the ten years prior to this disaster still have some resonance today. Ambitions to exploit new technology are not always matched by foresight in the planning, financing or management of projects. Contracts may be based on wrong assumptions, and prove difficult to enforce. Once a project has gathered momentum, those working on it may fear that any attempt to draw attention to risks or defects will be seen as disloyal. When work is completed, it cannot be assumed that formal inspections will reveal potential flaws, or that those using the technology will appreciate the need to follow the procedures laid down for them. Some possible parallels with recent experiences in NHS computing are noted.

  13. Failure Analysis about Joint Pipes for Natural Gas End Station%某含硫气田集气站汇管失效原因分析

    Institute of Scientific and Technical Information of China (English)

    乔宪一

    2012-01-01

    Depending on macroscopical shape, micro - structure, chemical composition analysis, mechanical performance test, crack apperance observation and corrosive composition, the cause of cracking for joint pipes of natural gas end station was analyzed. The result showed that the joint pipe crack including surface crack and hided crack occurred at the welding area, the property of crack were hydrogen induced cracking and stress oriented hydrogen induced cracking. Inferior anticorrosion coat at the equipment inner , surface is the main reason for cracking generating, another improper welding process accelerates cracking development obviously.%对开裂的天然气集气末站汇管进行了宏观形貌、显微组织、化学成分分析和力学性能测试、断口形貌观察以及腐蚀产物相组成确定,对其开裂原因进行了分析.结果表明:集气末站汇管开裂裂纹位于汇管的焊缝区,裂纹分为表面裂纹与隐藏裂纹,裂纹性质属氢致开裂和应力导向氢致开裂;设备内壁防腐涂层质量低劣是导致开裂的主要原因,焊接工艺不当对开裂有明显的促进作用.

  14. Three-dimensional measurement of welding residual stress of thick coolant pipe joint in nuclear reactor plant by inherent strain method

    International Nuclear Information System (INIS)

    The objective of this study is to ensure the safety of nuclear reactors. A number of accidents caused by leaks from welded zones at pipe penetration points of the reactor vessel or in coolant pipes have been reported at sites around the world. One of the main causes of such leaks is welding residual stress. It is therefore very important to know the welding residual stress in order to maintain the safety of the plants, estimate plant life cycle and design an effective maintenance plan. In this study, the inherent strain method combined with Finite Element Method (FEM) is applied to measure the welding residual stress accurately. A mock-up for a welded joint at a coolant pipe of an actual nuclear reactor was manufactured for the study. The inherent strain method is used to measure the three-dimensional residual stress distribution. In this method, the inherent strains are unknowns. When the residual stresses have a complex three-dimensional distribution, the number of unknowns becomes very large. The inherent strain distribution is therefore expressed with an appropriate function, significantly decreasing the number of unknowns. 10 kinds of inherent strain distribution functions are applied to estimate the residual stress distribution of the joint. Applicability of each function is diagnosed. Accuracy and reliability of analyzed results are judged from three points of view, that is, residuals, unbiased estimate of variance of errors and necessary conditions from welding mechanics. Most suitable function is selected, which brings most reliable result. The characteristics of the three-dimensional residual stress distribution are cleared. The circumferential stress and axial stress are important, related to stress corrosion cracking (SCC). The circumferential stress is estimated to be large tension near the outer surface of welding finish region. The large tensile axial stress is produced near the outer surface, widely in the circumferential direction. Near the inner

  15. Measurement of welding residual stresses of reactor vessel by inherent strain method. Measurement of residual stresses of pipe-plate penetration joint

    International Nuclear Information System (INIS)

    This study aims to ensure the safety of the nuclear power plants. The accidents of leak from the welded zones at the pipe penetration part of reactor vessel or at the coolant pipe are reported at home or abroad. One of the main causes is the welding residual stress. So, it is important to know the welding residual stress for the keeping of high safety of the plants, the estimation of plants life cycle and the plan of maintenance. The welded joints of the nuclear power plants have complex shapes, and the welding residual stresses also have complex distributions three-dimensionally. In this study, the inherent strain method combined with Finite Element Method (FEM) is used to measure the welding residual stresses accurately. The mock-up is idealized for the welded joint at the pipe penetration part of actual reactor vessel. The inherent strain method is applied to measure the residual stresses. In this method, the inherent strains are unknowns. When the residual stresses are distributed complexly in 3-dimensional stress-state, the number of unknowns becomes very large. So, the inherent strains are expressed with some functions to decrease the number largely. The theory, the experiment process and the analyzed results are explained. The characteristics of the distributions of residual stresses and their production mechanisms are discussed. The inherent strain method gives the most probable values and the deviations of the residual stresses. The deviations are small enough for the most probable values. It assures the high reliability of the estimated results. (author)

  16. A fracture mechanics safety concept to assess the impact behavior of ductile cast iron containers for shipping and storage of radioactive materials

    International Nuclear Information System (INIS)

    Within the scope of the German licensing procedures for shipping and storage containers for radioactive materials made of ductile cast iron, BAM performs approval design tests including material tests to ensure the main safety goals of shielding, leaktightness and subcriticality under ''Type B accident conditions''. So far the safety assessment concept of BAM is based essentially on the experimental proof of container strength by prototype testing under most damaging test conditions in connection with complete approval design tests, and has been developed especially for cylindrical casks like CASTOR- and TN-design. In connection with the development of new container constructions such as ''cubic cast containers'', and the fast developments in the area of numerical calculation methods, there is a need for a more flexible safety concept especially considering fracture mechanics aspects.This paper presents the state of work at BAM for such an extended safety concept for ductile cast iron containers, based on a detailed brittle fracture safe design proof. The requirements on stress analysis (experimental or numerical), material properties, material qualification, quality assurance provisions and fracture mechanics safety assessment, including well defined and justified factors of safety, are described. ((orig.))

  17. The Structure and Bond Strength of Composite Carbide Coatings (WC-Co + Ni) Deposited on Ductile Cast Iron by Thermal Spraying

    Science.gov (United States)

    Ksiazek, Marzanna; Boron, Lukasz; Radecka, Marta; Richert, Maria; Tchorz, Adam

    2016-02-01

    An investigation was conducted to determine the role of Ni particles in the WC-Co coating produced with the supersonic method on microstructure, mechanical, and wear properties in a system of type: WC-Co coating/ductile cast iron. The microstructure of the thermal-sprayed WC-Co + Ni coating was characterized by scanning electron and transmission electron microscopes as well as the analysis of chemical and phase composition in microareas (EDS, XRD). The microstructure of the WC-Co + Ni coating consisted of large, partially molten Ni particles and very fine grains of WC embedded in cobalt matrix, coming to the size of nanocrystalline. Moreover, the results were discussed in reference to examination of bending strength considering cracking and delamination in the system of (WC-Co + Ni)/ductile cast iron as well as hardness and wear resistance of the coating. It was found that the addition of Ni particles was significantly increase resistance to cracking and wear behavior in the studied system.

  18. 铸铁表面钨极氩弧硬化%Surface hardening of cast iron by tungsten inert gas arc

    Institute of Scientific and Technical Information of China (English)

    杨莉

    2001-01-01

    The wear resistibility of gray cast iron HT200 is improved by employing inert gas tungsten arc remelting and fast solidified, the effect of current and arc moving rate on the chilling layer properties are studied.And it is compared with laser hardening. The results show that Tungsten Inert Gas Arc remelting can improve the resistance to abrasion of cast iron and it is much better and cheaper technique than others.%以HT200为试验材料,用钨极氩孤对其表面进行了局部重熔硬化,得出了相关工艺参数对重熔处理后表层性能的影响,同时与铸铁表面激光硬化进行了对比。结果表明:铸铁表面氩弧硬化是有效提高其耐磨性,发挥自身潜力,降低成本的一项新工艺。

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

    International Nuclear Information System (INIS)

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

  20. 发动机球墨铸铁连杆疲劳强度分析%Analysis on Fatigue Strength of Nodular Cast Iron Connecting Rod in Engi

    Institute of Scientific and Technical Information of China (English)

    包雪鹏; 袁文; 武庆; 吴晓翔

    2001-01-01

    发动机连杆采用高强韧性球墨铸铁制造。介绍了采用小子样升降法试验该种发动机球墨铸铁连杆疲劳强度的方法和结果,预测了不同存活率下连杆的疲劳强度,分析了疲劳断口特征,指出夹渣、气孔和疏松等铸造缺陷是造成连杆失效的主要原因,如不存在铸造缺陷,疲劳裂纹起源于工字筋中心的显微疏松处。%The engine connecting rod is made by a nodular cast iron with high strength and toughness. This paper describes the methods and results of testing the fatigue strength of engine nodular cast iron connecting rod by small subsample lift and drop method, predicts the fatigue strength of connecting rod under different survival rates and analyzes the character of fatigue rupture notch. It is noted that the casting defects like inclusions, gas holes, looseness and etc. are main factors to cause the failure of connecting rods. The fatigue cracks sourced in looseness location in micro - structure of I shape rib center if casting defects do not exist

  1. Nb在高导热铸铁制动盘中的应用%Application of Niobium to High Thermal Conductivity Cast Iron Brake Disc

    Institute of Scientific and Technical Information of China (English)

    周文彬; 朱洪波

    2011-01-01

    在CE为4.4%~4.5%的高导热铸铁制动盘中加入不同量的铌合金,研究了Nb对其组织和力学性能的影响.结果表明,CE为4.4%、w(Nb)量为0.09%时,高导热铸铁制动盘石墨组织细化,力学性能得到一定的提高,磨损量降低,制动盘的抗热裂性提高.%Different amount of niobium alloy was added into the high thermal conductivity cast iron with CE of 4.4%~4.5% used for brake disc,and the effect of the niohium on the microstructure and mechanical properties of the casting were investigated. The result showed that,when CE was of 4.4%,Nb was of 0.09% .the graphite of the high thermal conductivity cast iron brake disc became finer,its mechanical properties were increased in some degree,its wear loss was reduced,its hot cracking resistance was improved.

  2. Kinetics of the formation of Fe2B layers in gray cast iron: Effects of boron concentration and boride incubation time

    International Nuclear Information System (INIS)

    The growth kinetics of Fe2B layers formed at the surface of gray cast iron were evaluated in this study. The pack-boriding process was applied to produce the Fe2B phase at the material surface, and the variables included three temperatures (1173, 1223 and 1273 K) and four exposure times (2, 4, 6 and 8 h). Taking into account the growth fronts obtained at the surface of the material and the mass balance equation at the Fe2B/substrate interface, the boron diffusion coefficient on the borided phase was estimated for the range of treatment temperatures. Likewise the parabolic growth constant, the instantaneous velocity of the Fe2B/substrate interface, and the weight gain in the borided samples were established as a function of the parameters τ(t) and α(C), which are related to the boride incubation time (t0(T)) and boron concentration at the Fe2B phase, respectively. Observation of the growth kinetics of the Fe2B layers in gray cast irons suggest an optimum value of boron concentration that is in good agreement with the set of boriding experimental conditions used in this work.

  3. Laser treatment of dual matrix cast iron with presence of WC particles at the surface: Influence of self-annealing on stress fields

    Science.gov (United States)

    Yilbas, B. S.; Akhtar, S. S.; Karatas, C.; Boran, K.

    2016-01-01

    Laser control melting of dual matrix cast iron surface is carried out. A carbon film containing 15% WC particles is formed at the surface prior to the laser treatment and the spiral tracks are adopted for laser scanning at the workpiece surface. Morphological, metallurgical, microhardness, and scratch resistance of the laser treated surface are examined using analytical tools. Temperature and stress fields in the laser irradiated region are predicted incorporating ABAQUS finite element code. Predictions of temperature and residual stress at the laser treated surface are validated with the thermocouple and the X-ray diffraction data. It is found that surface temperature and residual stress predictions agree well with their counterparts corresponding to thermocouple data and findings of X-ray diffraction technique. Laser treated surface is free from asperities including voids and micro-cracks despite the mismatch of thermal expansion coefficients of WC and dual matrix cast iron. This behavior is attributed to the self-annealing effects of recently formed spiral tracks on the previously formed tracks during the laser treatment process; in which case, the self-annealing effect modifies the cooling rates and lowers thermal stress levels in the laser treated layer. Laser treated layer consists of a dense region composing of fine grains and WC particles, dendritic and featherlike structures below the dense layer, and the heat affected zone.

  4. Influence of Niobium on Thermal Fatigue Properties of Gray Cast Irons%Nb对灰铸铁热疲劳性能的影响

    Institute of Scientific and Technical Information of China (English)

    朱洪波; 闫永生; 孙小亮; 华勤; 翟启杰

    2011-01-01

    采用Uddeholm热疲劳方法测定了Nb对灰铸铁热疲劳性能的影响,试验结果表明:(1)Nb的加入能够提高灰铸铁的抗热疲劳性能,随着w(Nb)的增加,试样最大裂纹深度和宽度都逐渐减小;(2)由于Nb细化石墨使裂纹源减少和裂纹扩展途径变细,Nb元素能够改善材料表面经热疲劳处理后恶化的性能.%By adopting Uddeholm thermal fatiguing method , the influence of niobium on the thermal fatigue properties of the gray cast irons was tested. The results showed: ( 1)Niobium addition could improve the thermal fatigue resistance of the gray cast irons. Both the maximum cracking depth and width gradually reduced with increase of the niobium adding amount; (2)Since the niobium could make the graphite finer, reduce the number of cracking sources and make the crack extending tracks narrower, therefore it could reduce the properties worsening of the material after having been thermally fatiguing treated.

  5. Thermal Test and Numerical Simulation of Nodular Cast Iron Cooling Stave%球墨铸铁冷却壁热态实验与数值模拟

    Institute of Scientific and Technical Information of China (English)

    洪军; 左海滨; 张建良; 李峰光; 沈猛; 铁金艳

    2014-01-01

    为测定消失模工艺生产的球墨铸铁冷却壁的实际冷却性能,进行1∶1热态实验.同时建立铸铁冷却壁三维稳态传热模型,模拟铸铁冷却壁的温度场分布.热态实验结果表明:该球墨铸铁冷却壁壁体与冷却水之间的综合换热系数为228W/(m2·℃),与日本新日铁第四代冷却壁相近.炉温变化对冷却壁热面温度的影响大于其对冷却壁冷面温度的影响.提高冷却水速可以降低冷却壁壁体温度,但效果不明显.模型计算结果与热态实验的比较,验证了计算模型的有效性.%To determine the actual performance of nodular cast iron stave produced by lost foam casting,the 1∶1 thermal test was carried out.The 3D steady-state heat transfer model was established to calculate the temperature field of cast iron cooling stave.Thermal test results show that the cast iron cooling stave has good cooling ability,the integrated heat transfer coefficient is 228 W/ (m2· ℃),which is close to Nippon Steel fourth-generation stave.Effect of furnace gas temperature on hot face temperature is greater than effect on cold face temperature.Increasing of cooling water velocity can lower hot face temperature,but the effect is not obvious.The comparison between computational model and thermal test verified the validity of the computational model.

  6. Experience with one-layer high-strength ferrite and austenite bellous of pipe joint compensators in 20 ata hot steam pipelines

    International Nuclear Information System (INIS)

    Numerous signs of damage have occured on one-layer high-strength ferrite and austenite bellows of pipe joint compensators in 20 ata superheated-steam pipelines. From a precise analysis of the damage cases, it was found that in ferrite material, the high creep-alternating stress lead to damage, whereas in the austenite material, above all the difficult workability and the slight ductility at operational temperature were determining factors. An attempt was made to prolong the lifetime of the compensators equipped with ferrite bellows by increasing the bellow wall thickness from 3 to 4 mm. These new compensators have so far achieved an operational time of about 10,000 hours with 50 drives without visible deformations or damage. (orig./LH)

  7. Morphologies of Carbides in Nb-Cr White Cast Irons and Their Influence on Properties%铌铬白口铸铁中碳化物的形态及其对性能的影响

    Institute of Scientific and Technical Information of China (English)

    子澍

    2011-01-01

    介绍了铌铬白口铸铁中的碳化物形态及分布规律.认为铌在白口铸铁中以NbC形式与奥氏体形成共晶体,在共晶体内,NbC呈条形放射状;在铌铸铁中加入钛,TiC先于NbC析出,随后NbC围绕TiC结晶,最终形成团块状,使这种白口铸铁具有更高的抗磨性能和更高的韧性.%Morphologies and distribution rule of the carbides in Nb-Cr alloyed white cast irons were introduced. It was considered that the niobium, existing as NbC phase, formed the eutectic with the austenite in the white cast irons and the NbC was of the sprawl shape in the eutectic. When adding Titanium into the niobium cast iron, the TiC precipitated before the NbC, and then the NbC crystallized around the TiC and formed finally a lump-shaped complex carbide that made this type of white cast iron having more higher ahrasion-resistance and more higher toughness.

  8. Influence of closure on the 3D propagation of fatigue cracks in a nodular cast iron investigated by X-ray tomography and 3D volume correlation

    International Nuclear Information System (INIS)

    Synchrotron X-ray tomography was performed during in situ fatigue crack propagation in two small-size specimens made of nodular graphite cast iron. While direct image analysis allows us to retrieve the successive positions of the crack front, and to detect local crack retardation, volume correlation allows for the measurement of displacement fields in the bulk of the specimen. The stress intensity factors (SIFs), which are extracted from the measured displacement fields and the corresponding local crack growth rate all along the front, are in good agreement with published results. In particular, it is possible to link the non-propagation of a crack with crack closure in the crack opening displacement maps or with a local value of the measured SIF range. It is shown that a non-uniform closure process along the crack front induces an asymmetric arrest/growth of the crack.

  9. Crack closure and stress intensity factor measurements in nodular graphite cast iron using three-dimensional correlation of laboratory X-ray microtomography images

    International Nuclear Information System (INIS)

    Three-dimensional (3-D) tomographic images of a nodular graphite cast iron obtained using a laboratory X-ray source were used to analyze the opening of a fatigue crack during in situ mechanical loading. Direct image analysis and digital image correlation are utilized to obtain the 3-D morphology and front location of the crack, as well as the displacement fields in the bulk of the specimen. From digital image correlation results it is possible to extract the crack opening displacement (COD) map in the whole sample cross-section and to compute stress intensity factors (SIFs) all along the crack front, even for COD values that are less than the image resolution. The comparison of COD maps with local values of the SIF enabled for an estimation of the opening SIF (Kop) equal to 6 MPa m1/2.

  10. Mechanical properties dependency on chemical composition of spheroidal graphite cast iron; Dependencia de las propiedades mecanicas y de la composicion quimica en la fundicion de grafito esferoidal

    Energy Technology Data Exchange (ETDEWEB)

    Gonzaga-Cinco, R.; Fernandez-Carrasquilla, J.

    2006-07-01

    With this work, we try to study the chemical composition of four specimens in form of stair of ductile cast iron to determine the influence of the chemical composition of different alloying elements on microstructure and on mechanical properties. The dimensions of each specimens are 200 x 100 x 50 mm. Cooling rate has been considered to be different for each one of the four stairs when determining the mechanical properties, therefore, grain size varies in each case. In this analysis, the different microstructures of the stairs have been considered. Influence of the thickness on hardness of each specimen has been taken into account. Heat treatments are not used. Yield and tensile strength are determined. Charpy tests have been done. Rockwell and Brinell hardness are determined. (Author)

  11. 低温一次搪铸铁搪瓷研究%Study on One- Coat Low Temperature Firing Cast Iron Enamel

    Institute of Scientific and Technical Information of China (English)

    李景学; 钱蕙春; 蒋伟忠

    2011-01-01

    A low temperature fired and one coated cast iron enamel with excellence adherence strength and good surface quality has been developed by introducing complex adherence agents, such as, CoO,NiO,CuO,FeO, into enamel frit, and using B2O3, TiO2 to substitute for SiO2, AI2O3 in enamel frit.%采用CoO、NiO、CuO、FeO等多种密着剂引入到铸铁搪瓷釉配方,采用三氧化二硼、二氧化钛等取代二氧化硅、三氧化二铝,研制出搪瓷烧成温度低,密着性能和搪瓷表面质量优良的一次搪铸铁搪瓷.

  12. Applied Research of Laser Surface Hardening of Cast Iron Hot Roll%铸铁热轧辊激光表面强化应用研究

    Institute of Scientific and Technical Information of China (English)

    许巧玉

    2012-01-01

    运用激光表面强化理论和技术,对NiCrMo半冷硬铸铁热轧辊材料进行激光相变硬化和熔凝处理后,表层分别得到针状马氏体和莱氏体白口组织,硬度由原来的51 HRC提高到70 HRC左右,材料的耐磨性提高.%Applying the theory and technology of laser surface hardening, NiCrMo chilled cast iron hot roll material was processed by laser transformation hardening and surface melting. The results show that the white organizations of acicular martensite and ledeburite are obtained in the surface layer, the hardness is increased from 51 HRC to about 70 HRC, and the wear resistance and other performance of the materials are also improved.

  13. Fractomechanical Properties of As-Cast and Austempered SG Cast Iron Between -40 °C and +20 °C

    Directory of Open Access Journals (Sweden)

    V.E. Fierro

    2002-06-01

    Full Text Available The spheroidal graphite (SG cast iron fractomechanical response varies with the test temperature and with the microstructure parameters. In the present paper, we analyze this variation performing fractomechanical tests in a temperature range from -40°C to +20°C, doing also Charpy and tensile tests for material characterization. The tests were carried out on as-cast samples and heat treated samples to obtain an ADI grade 1. In both cases, we studied samples taken from two well differentiated "Y" block sizes. The results obtained show that, for the chemical composition analyzed, both castings have a fractomechanical response decrease as the temperature diminishes. Besides, the block size enlargement produce a deterioration of the mechanical properties (the fracture toughness, mainly, for both castings.

  14. Introduction to ultrasonic thickness of cast iron cylinder%浅谈铸铁烘缸的超声波测厚

    Institute of Scientific and Technical Information of China (English)

    陈帅; 邓传奇; 伍广; 周传健

    2016-01-01

    本文介绍了超声波测厚的原理及其特有优势,说明了超声波测厚的材料选取及准备事项,将各种材料进行了比较。通过此方法,可测得对铸铁烘缸较精确的厚度。最后总结了超声波测厚技术的发展方向。%This paper introduces the principle of ultrasonic thickness and its unique advantages,analyzes the ultrasonic thickness of material selection and preparation matters,and the different materials were compared. Through this method, precise thickness can be measured on cast iron cylinder.Finally ,it summarizes the development direction of ultrasonic thickness measurement technology.

  15. Uniaxial Fatigue of HDPE-100 Pipe. Experimental Analysis

    Directory of Open Access Journals (Sweden)

    A. Aid

    2014-04-01

    Full Text Available In this paper, an experimental analysis for determining the fatigue strength of PE-100, one of the most used High Density Polyethylene (HDPE materials for pipes, under cyclic axial loadings is presented. HDPE is a thermoplastic material used for piping systems, such as natural gas distribution systems, sewer systems and cold water systems, which provides a good alternative to metals such as cast iron or carbon steel. One of the causes for failures of HDPE pipes is fatigue which is the result of pipes being subjected to cyclic loading, such as internal pressure, weight loads or external loadings on buried pipes, which generate stress in different directions: circumferential, longitudinal and radial. HDPE pipes are fabricated using an extrusion process, which generates anisotropic properties. By testing in the Laboratory a series of identical specimens obtained directly from PE-100 HDPE pipes in longitudinal directions, the relationships between amplitude stress and number of cycles (S-N curve test frequency 2 Hz and stress ratio R = 0.0 are established.

  16. Theoretical basis of Al-Si coat crystallization on gray and nodular cast iron and making the layered items using it

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2011-12-01

    Full Text Available Purpose: The aim of this study was to present studies of crystallization and the construction of the coat consisting of Al-Si alloys, also with alloy additives: Ni, Cu and Mg, deposited on gray and nodular cast iron, and the connection through this coat the layered item. On this basis, a model of creating a coat and layered item was developed.Design/methodology/approach: Studies of coats and layered products were carried out on scanning electron and optical microscopes. The chemical microanalysis and diffraction of backward scattered atoms in the characteristic areas of the coat and substrate material was made.Findings: : In this paper the influence of the most important technological factors on the thickness and phase construction of the silumin coat and connection quality in the layered item was presented.Research limitations/implications: Currently, research of dip application of coats made of silumins containing: Cu, Ni, Mg, Cr, Mo, W and V on non-alloy and alloy steels and the manufacture of layered items to their use are conducted.Practical implications: Dip coats are used as protective coats or intermediate coat of layered item. The paper presents an example of the implementation for the manufacture of the layered items low-alloyed gray cast iron-silumin coat-silumin reciprocating compressor body for room air conditioning.Originality/value: Originality of the paper consists in elaborating of the theoretical model of forming the diffusion layer made of Al-Si-M silumin on iron alloys. Theoretical basis of layers production were elaborated too. They are significant for collar fillings production in high-pressure combustion engines pistons, as anticorrosive layers and for layered items production.

  17. A Predictive Framework for Thermomechanical Fatigue Life of High Silicon Molybdenum Ductile Cast Iron Based on Considerations of Strain Energy Dissipation

    Science.gov (United States)

    Avery, Katherine R.

    Isothermal low cycle fatigue (LCF) and anisothermal thermomechanical fatigue (TMF) tests were conducted on a high silicon molybdenum (HiSiMo) cast iron for temperatures up to 1073K. LCF and out-of-phase (OP) TMF lives were significantly reduced when the temperature was near 673K due to an embrittlement phenomenon which decreases the ductility of HiSiMo at this temperature. In this case, intergranular fracture was predominant, and magnesium was observed at the fracture surface. When the thermal cycle did not include 673K, the failure mode was predominantly transgranular, and magnesium was not present on the fracture surface. The in-phase (IP) TMF lives were unaffected when the thermal cycle included 673K, and the predominant failure mode was found to be transgranular fracture, regardless of the temperature. No magnesium was present on the IP TMF fracture surfaces. Thus, the embrittlement phenomenon was found to contribute to fatigue damage only when the temperature was near 673K and a tensile stress was present. To account for the temperature- and stress-dependence of the embrittlement phenomenon on the TMF life of HiSiMo cast iron, an original model based on the cyclic inelastic energy dissipation is proposed which accounts for temperature-dependent differences in the rate of fatigue damage accumulation in tension and compression. The proposed model has few empirical parameters. Despite the simplicity of the model, the predicted fatigue life shows good agreement with more than 130 uniaxial low cycle and thermomechanical fatigue tests, cyclic creep tests, and tests conducted at slow strain rates and with hold times. The proposed model was implemented in a multiaxial formulation and applied to the fatigue life prediction of an exhaust manifold subjected to severe thermal cycles. The simulation results show good agreement with the failure locations and number of cycles to failure observed in a component-level experiment.

  18. Survey of creep damage in a T-joint from a retired steam pipe system; Kartlaeggning av krypskador i ett T-stycke fraan ett utrangerat aangnaet

    Energy Technology Data Exchange (ETDEWEB)

    Storesund, Jan

    2009-06-15

    Unexpected failures and cracking have recently occurred in steam piping by creep although the service temperatures have been significantly below the limit temperature for creep rupture. Characterisation of such damage, mapping of the presence in Swedish plants and better knowledge of the presumptions for the phenomenon have been received in previous Vaermeforsk projects. A steam pipe system that never had been inspected or tested with respect to creep was replica tested at a number of test positions. The steam data was 450 deg C and 65 bars and the age was 35 years of almost continuous operation. Extensive creep damage was found in one T-joint. This component was the object of interest in the present project. Metallographic investigations were carried out by cutting the T-joint into sections for through thickness examinations of possible creep damage as well as characterisation of the microstructure. Ten sections were selected at different positions of four welds that the T-joint covered. In addition to the characterisation by means of creep damage and possible microstructure degradation or other anomalies the purpose of the investigation was to find out if the replica testing was a conservative method or not. Other expectations on the project were to gain additional knowledge of the creep phenomena's below the limit temperature and a verification of the computation models for crack propagation that were used in the previous Vaermeforsk projects in the area. Nine chemical analyses were performed on all different parent and weld metals of the T-joints. Most analyses resulted in a composition close to the nominal one, that is 13CrMo4-4 steel, the most frequently used heat resistant steel in steam piping for steam temperatures around the limit temperature in Sweden. The parent metal in which the creep cracks were found, however, had a composition that corresponds to 0,5Cr0,6Mo0,3V steel, a low alloy steel that is liable to cracking. Furthermore the branch part of

  19. The microstructure and mechanical properties of welded joints in the pipes of nuclear power stations after sustained service

    International Nuclear Information System (INIS)

    The microstructure and mechanical properties are studied for welded joints of specimens cut out of Du 300 and Du 500 pipelines of Leningrad and Novovoronezh NPPs after operation for 70 and 100 thousand h. Heat aging effect simulating the influence of operation conditions on microstructure and properties of welded joints is investigated. It is shown that on long-run operation an embrittlement may occur along with a decrease in crack resistance of weld metal of 08Kh18N10T and 08Kh18N12T steel pipelines. The microstructural changes are revealed which are capable of reducing mechanical properties under operational conditions

  20. Residual stress distribution in austenitic stainless steel pipe butt-welded joint measured by neutron diffraction technique

    International Nuclear Information System (INIS)

    Residual stress is inevitable consequence of welding or manufacturing process, which might greatly affect propagation of high-cycle fatigue or SCC crack. In order to evaluate damages due to the crack, it is required to estimate residual stress and to reflect them to the evaluation process as well. The magnitude and distribution of residual stress greatly depend on the individual process of welding or manufacturing, while the accuracy of prediction or measurement is still insufficient. This paper reports the result of residual stress measurement of butt-welded pipe made of austenitic stainless steel. It also intended to improve prediction and measurement techniques concerning to residual stress. The measurement was conducted by neutron diffraction technique employing the diffractometer for residual stress analysis developed by Japan Atomic Energy Agency. The measured results showed typical characteristics of butt-welded pipe both in decline of stress along axial direction and in radial distribution of bending due to axial stress. The measured result agreed qualitatively with the result predicted by the finite element analysis. A quantitative comparison between measured result and analysis showed a shift of the measured stress toward higher tensile. The measured result was also compared with the results by X-ray diffraction and strain-gauge methods to grasp the distinctive results of the methods. (author)

  1. Real-time corrosion control system for cathodic protection of buried pipes for nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Tae; Kim, Hae Woong; Kim, Young Sik [School of Materials Science and Engineering, Andong National University, Andong (Korea, Republic of); Chang, Hyun Young; Lim, Bu Taek; Park, Heung Bae [Power Engineering Research Institute, KEPCO Engineering and Construction Company, Seongnam (Korea, Republic of)

    2015-02-15

    Since the operation period of nuclear power plants has increased, the degradation of buried pipes gradually increases and recently it seems to be one of the emerging issues. Maintenance on buried pipes needs high quality of management system because outer surface of buried pipe contacts the various soils but inner surface reacts with various electrolytes of fluid. In the USA, USNRC and EPRI have tried to manage the degradation of buried pipes. However, there is little knowledge about the inspection procedure, test and manage program in the domestic nuclear power plants. This paper focuses on the development and build-up of real-time monitoring and control system of buried pipes. Pipes to be tested are tape-coated carbon steel pipe for primary component cooling water system, asphalt-coated cast iron pipe for fire protection system, and pre-stressed concrete cylinder pipe for sea water cooling system. A control system for cathodic protection was installed on each test pipe which has been monitored and controlled. For the calculation of protection range and optimization, computer simulation was performed using COMSOL Multiphysics (Altsoft co.)

  2. The Role of Niobium in the High Chromium Cast Iron Hardfacing Metal%Nb在高铬铸铁型堆焊金属中的作用

    Institute of Scientific and Technical Information of China (English)

    潘川; 吴智武; 王移山; 柳小坚; 何志勇

    2012-01-01

    在高铬铸铁型堆焊金属中,用7%的铌元素取代相同摩尔数的铬元素,制成含铌的明弧自保护药芯焊丝.运用彩色金相分析、扫描电镜及能谱分析、X射线物相分析、洛氏硬度测试等技术,研究了铌在高铬铸铁型堆焊金属中的作用,分析了线能量对高铬铸铁型堆焊金属组织和硬度的影响.结果表明:铌元素能够优先与碳结合,形成弥散分布的碳化铌结晶核心,阻止初生碳化物的生长,具有明显的细化晶粒作用.不论是否添加铌元素,同种堆焊金属线能量越小,碳化物尺寸越细小;裂纹数量越多,裂纹分布越均匀,且裂缝间隙越小.可以通过控制线能量来控制焊缝的裂纹分布,防止堆焊层脱落.改变线能量以及用7%的铌元素取代相同摩尔数的铬元素,其洛氏硬度值基本保持不变,均在60 HRC左右.%In this paper, self-shielded flux cored wire including niobium for open arc welding was prepared with 7% niobium element to replace the same number of moles of chromium element in the high chromium cast iron hardfacing metal. The role of niobium in the high chromium cast iron hardfacing metal was studied, the effect of heat input on microstructure and hardness of the high chromium cast iron hardfacing metal was analyzed, by means of color metallography, SEM, EDS, XRD and testing Rockwell hardness techniques. The results showed that niobium element can preferentially combined with carbon to form dispersion distribution of NbC crystal core, to prevent the growth of primary carbides, thus plays a significant role of grain refinement. The heat input in the same hardfacing metal is smaller, whether or not to add niobium element, the size of carbides is finer, the number of cracks is greater, its distribution is more homogeneous and its gap was smaller. The crack distribution can be controlled by adjusting heat input in order to prevernt hardfacing layer falling off. No matter changing heat input or

  3. Plugging device for nuclear pipes

    International Nuclear Information System (INIS)

    The plugging device assembled near an access opening is used for plugging the primary pipes. This plugging device comprises a rim flexible joint put in mechanical pressure by the displacement of mechanical pieces. This joint has a central compartment pressurizable. This joint is fixed by a stirrup-piece and a shaft in support on the tube plate

  4. Study of the influence of Cu and Ni on the kinetics of strain-induced martensite in austempered ductile cast iron; Estudio de la influencia del Cu y Ni en la cinetica de transformacion martensitica inducida por deformacion en fundiciones nodulares austemperadas

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, D.; Navea, L.; Garin, J.; Aguilar, C.; Guzman, A.

    2013-09-01

    The objective of this work was to study the influence of copper and nickel on the kinetics of strain-induced martensite in austempered ductile cast iron. The austempered ductile cast irons were obtained from two ductile cast irons with different copper and nickel contents by means of austempering treatment. The deformation was carried out using a rolling mill. The quantification of the phases was obtained by means of X ray diffraction, while the microstructural characterization was carried out using optical and scanning electron microscopy. It was proved that the kinetics of strain-induced martensite in austempered ductile cast iron can be modeled using the equations proposed by Olson- Cohen and Chang et al. Based on the results obtained from these analyses, it is possible to conclude that the nickel and copper complicate the martensite transformation because these elements increase the staking fault energy of the austenite and its thermodynamic stability. (Author)

  5. Fast connection of large-diameter PE pipes. A new generation of heating coil welding technologies. A technical comparison between the new wedge-shaped joint and the conventional cylindrical foint for PE pipes d 1000 and larger; PE-Grossrohre im Handumdrehen verbinden. Eine neue Generation der Heizwendelschweisstechnik. Ein technischer Vergleich zwischen der neuen Keilmuffe und der herkoemmlichen zylindrischen Muffe fuer PE-Rohre d 1000 und groesser

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Robert [FRIATEC AG, Mannheim (Germany)

    2011-07-01

    Wedge-shape joints are a revolution in large-diameter pipe connection. Fitting is simplified considerably as compared to conventional cylindrical joints. Reproducible high-quality connections are achieved at only a fraction of the time formerly required. Assembly follows clear and simple rules. Anybody who can assemble a flange will be able to cope with the tightening system of the wedge-shaped joint.

  6. Investigation on Surface Hardening of Cast Iron by Tungsten Inert Gas Arc Remelting%铸铁表面钨极氩弧重熔强化的研究

    Institute of Scientific and Technical Information of China (English)

    姚军; 梁文心

    2000-01-01

    为了提高铸铁表面的耐磨性,以HT200为试验材料,用钨极氩弧对其进行了局部重熔强化的系统研究,得出了相关工艺参数对重熔处理后表层组织和性能的影响规律。同时与镍基自熔合金喷焊及铸铁激冷处理表面强化法做了对比试验,结果表明,铸铁钨极氩弧重熔后激冷法是有效提高其耐磨性,发挥自身潜力,降低成本的一项新工艺。%To improve the resistance to abrasion for surface of cast iron,the wear resistibility of grey cast iron HT200 is increased by employing inert gas tungsten arc remelt and fast solidified.The effect of current and arc moving rate on the chilling layer microstructure and some properties are studied.The results are compared with those of spray coating by nickel alloys and cast iron chilled treating and it proved that rapid chilling of A-type cast iron by tungsten inert shielded gas arc melting as an energy source is much better and cheaper technique than others.And also promises to provide a new method for controlling microstructure and properties.

  7. Effect of heat treatment on the wear and corrosion behaviors of a gray cast iron coated with a COLMONOY 88 alloy deposited by high velocity oxygen fuel (HVOF) thermal spray

    OpenAIRE

    ÖZ, A.; R. Samur; Mindivan, H.; Demir, A.; S. Sagiroglu; A. K. Yakut

    2013-01-01

    The present work has been conducted in order to determine the influence of heat treatment on the wear and corrosion behaviours of a gray cast iron substrate coated with a Ni base coating deposited by HVOF thermal spray. The wear resistance of the coatings was obtained using a reciprocating wear tester by rubbing a 10 mm diameter steel ball on the coatings at normal atmospheric conditions. Corrosion tests were performed using potentiodynamic polarization measurements in a 3,5 % NaCl solution. ...

  8. Formation Reason and Countermeasures of Non-Metal Inclusions of Cast Irons%铸铁非金属夹杂物的形成原因与应对措施

    Institute of Scientific and Technical Information of China (English)

    张文和; 王峰; 赵鲁生

    2011-01-01

    The composition and source of slag of cast irons melted in cupola and medium frequency furnace was introduced. The measures to reduce non-metal inclusions in cast irons were proposed as follows: ( 1 )improving metallurgical quality of the cast irons; (2 )improving the morphology and distribution of the nonmetal inclusions. The formation reason of the secondary slag was described. It's considered that, by adopting proper measures and iron melt treating technique, the secondary oxidation of the iron melt and its harmful effect can be reduced.%介绍了冲天炉和中频炉熔炼铸铁的炉渣成分及来源,提出减少铸铁内部非金属夹杂物的措施:(1)提高铸铁的冶金质量;(2)改善铸铁中非金属夹杂物的形态及分布.描述了铁液二次渣的形成原因,认为采取适宜的措施及铁液处理技术,可以减轻铁液二次氧化及其不利影响.

  9. 高硅合金耐热铸铁生产球墨铸铁模具的研制%Research on producing ductile iron mould with high silicon alloy heat resistant cast iron

    Institute of Scientific and Technical Information of China (English)

    梁冰利; 王宏亮; 韩黎

    2012-01-01

    对铸铁模具使用工况进行了分析,采用了高硅合金耐热铸铁为生产球墨铸铁模具的材质,并介绍了高硅合金耐热球墨铸铁模具的消失模铸造工艺、冶炼工艺、热处理工艺以及该材质模具的实际使用效果.实际生产表明:高硅合金耐热球墨铸铁具有优越的综合耐热疲劳性能,大大提高了模具寿命.%The actual operating conditions of cast iron mould were analyzed. The silicon alloy heat resistant cast iron was adopted to produce ductile iron mould, and the lost foam casting process, smelting process, heat treatment process of the high silicon alloy heat resistant ductile iron mould as well as the actual use effect of the mould with this material were introduced. The practical production shows that the high silicon alloy heat resistant cast iron has superior heat-resistant and fatigue properties, which improves the mould life.

  10. Entropy-Based weighting applied to normal boundary intersection approach: the vertical turning of martensitic gray cast iron piston rings case

    Directory of Open Access Journals (Sweden)

    Luiz Célio Souza Rocha

    2015-10-01

    Full Text Available In practical situations, solving a given problem usually calls for the systematic and simultaneous analysis of more than one objective function. Hence, a worthwhile research question may be posed thus: In multiobjective optimization, what can facilitate the decision maker in choosing the best weighting? Thus, this study attempts to propose a method that can identify the optimal weights involved in a multiobjective formulation. Our method uses functions of Entropy and Global Percentage Error as selection criteria of optimal weights. To demonstrate its applicability, we employed this method to optimize the machining process for vertical turning martensitic gray cast iron piston rings, maximizing the productivity and the life of cutting tool and minimizing the cost, using feed rate and rotation of the cutting tool as the decision variables. The proposed optimization goals were achieved with feed rate = 0.35 mm rev-1 and rotation = 248 rpm. Thus, the main contributions of this study are the proposal of a structured method, differentiated in relation to the techniques found in the literature, of identifying optimal weights for multiobjective problems and the possibility of viewing the optimal result on the Pareto frontier of the problem. This viewing possibility is very relevant information for managing processes more efficiently.

  11. Analysis on Fracture of Rare Earth Nodular Cast Iron Crank Shaft%稀土球墨铸铁曲轴断裂的分析

    Institute of Scientific and Technical Information of China (English)

    张琴

    2012-01-01

    The fracture strength and service life of the rare earth nodular cast iron crank shaft for diesel engine is researched based on the linear elastic fracture mechanics theory. The main reason of its fracture is that a defect exists at the transition fillet position of the crank arm and the connecting rod journal, where it will lead to a crank shaft buckling fracture after the fatigue reaches the critical condition. According to the fracture mechanics theory and tests, put forward some ways to reduce the fracture rate.%运用线弹性断裂力学理论研究柴油机稀土球墨铸铁曲轴断裂强度和寿命问题。曲轴断裂的主要原因在于曲柄臂与连杆轴颈过渡圆角处存在缺陷,这个位置的缺陷在疲劳扩展达到临界状态时便导致曲轴失稳断裂。根据断裂力学理论和实验分析,提出了降低断裂率的一些途径。

  12. A New Method For Advanced Virtual Design Of Stamping Tools For Automotive Industry: Application To Nodular Cast Iron EN-GJS-600-3

    Science.gov (United States)

    Ben-Slima, Khalil; Penazzi, Luc; Mabru, Catherine; Ronde-Oustau, François; Rezaï-Aria, Farhad

    2011-05-01

    This contribution presents an approach combining the stamping numerical processing simulations and structure analysis in order to improve the design for optimizing the tool fatigue life. The method consists in simulating the stamping process via AutoForm® (or any FEM Code) by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis. The result of this analysis is used for life prediction of the tool using S-N fatigue curve. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This optimization method is applied for a cast iron EN-GJS-600-3 as candidate stamping tool materiel. The room temperature fatigue S-N curves of this alloy are established in laboratory under uniaxial push/pull cyclic experiments on cylindrical specimens under a load ratio of R (σmin/σmax) = -2.

  13. Effect of powder reactivity on fabrication and properties of NiAl/Al2O3 composite coated on cast iron using spark plasma sintering

    Science.gov (United States)

    Beyhaghi, Maryam; Kiani-Rashid, Ali-Reza; Kashefi, Mehrdad; Khaki, Jalil Vahdati; Jonsson, Stefan

    2015-07-01

    Powder mixtures of Ni, NiO and Al are ball milled for 1 and 10 h. X-ray diffractometry and differential thermal analysis show that while ball milling for 1 h produced mechanically activated powder; 10 h ball milling produced NiAl and Al2O3 phases. Dense NiAl/Al2O3 composite coatings are formed on gray cast iron substrate by spark plasma sintering (SPS) technique. The effect of powder reactivity on microstructure, hardness and scratch hardness of NiAl/Al2O3 coatings after SPS is discussed. Results show that in the coating sample made of mechanically activated powder in situ synthesis of NiAl/Al2O3 composite coating is fulfilled and a thicker well-formed diffusion bond layer at the interface between coating and substrate is observed. The diffusion of elements across the bond layers and phase evolution in the bond layers were investigated. No pores or cracks were observed at the interface between coating layer and substrate in any of samples. Higher Vickers hardness and scratch hardness values in coating made of 10 h ball milled powder than in coating fabricated from 1 h ball milled powder are attributed to better dispersion of Al2O3 reinforcement particles in NiAl matrix and nano-crystalline structure of NiAl matrix. Scratched surface of coatings did not reveal any cracking or spallation at coating-substrate interface indicating their good adherence at test conditions.

  14. Corrosion behaviour of ductile cast irons partially modified with silicon in 0.03 M NaCl; Comportamiento frente a la corrosion de fundiciones con grafito laminar y esferoidal parcialmente modificadas con silicio en NaCl 0,03 M

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, M. A.; Niklas, A.; Conde, A.; Mendez, S.; Sertucha, J.; Damborenea, J. J. de

    2014-07-01

    NaCl. The increasing demand of ductile cast irons with extensive technological applications leads to enlarge the corrosion resistance of this group of metallic materials. In this sense, the use of different chemical compositions on such cast irons becomes one of the most interesting aspects among the different ways to improve their behaviour against corrosion due to the extra opportunity for increasing the mechanical properties. Additionally such improvements have to be made without any increase of processing costs to keep the interesting competitiveness of developed cast irons. In the present work the preliminary results obtained from corrosion tests made on a group of cast irons with different chemical compositions are presented. Among ductile cast irons, silicon content has been varied in order to investigate the effect of this element on corrosion resistance of the alloys. The obtained results show a slight improvement of this property for the alloys with high silicon content with respect to the conventional ones though such effect was found in the first time period of the corrosion tests. Interestingly this improvement was found for alloys that exhibit better tensile properties than the conventional ductile irons. Thus an important way for developing new ductile cast irons with improved corrosion properties by alloying has been opened. (Author)

  15. Cured in Place Pipe Repair

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Insituform Technologies Inc. offers a pipe lining system called Paltem which uses a woven synthetic fiber covered with a polyester elastomer as the lining material. This system is used to rehabilitate pressure pipelines that have been damaged by corrosion or are experiencing leakage through joints, pinholes or other pipe defects.

  16. 碳含量对纳米结构白口铸铁组织与力学性能的影响%Effect of carbon content on microstructure and mechanical properties of nanostructure white cast iron

    Institute of Scientific and Technical Information of China (English)

    喇培清; 甄小娟; 胡苏磊; 李翠玲; 魏玉鹏; 卢学峰; 王鸿鼎; 魏福安

    2014-01-01

    The nanostructure white cast irons without expensive elements were prepared by aluminothermic reaction, the effect of carbon content on its microstructures and mechanical properties was studied by XRD, OM, SEM, tension and compression test . The results show that, the white cast irons consist of pearlite with different shapes and cementite, the lamellar pearlite decreases and granular pearlite increases with increasing the carbon content. The average lamellar spacing of the pearlite phase is 165, 231 and 250 nm, respectively. With increasing carbon content, the vickers hardness of nanostructure white cast iron is 552, 577 and 575 HV, compressive strength is 2 224, 2 460 and 2 220 MPa, and tensile strength is 383, 416 and 245 MPa, respectively, which are all first increases and then decreases with increasing carbon content; the elongation rate is 3%, 2.5% and 1%. The mechanical properties of nanostructure white cast iron without expensive alloying elements are the same to Ni-Hard2 cast iron.%以铝热反应法制备无昂贵合金元素添加的纳米结构白口铸铁,采用XRD、OM、SEM和拉伸及压缩等分析、测试手段研究碳含量对纳米结构白口铸铁组织和力学性能的影响。结果表明:随碳含量增加,白口铸铁由不同形态的珠光体和渗碳体组成,其中层片状珠光体含量减少,粒状珠光体含量增加;层片状珠光体的片间距分别为165、231和250 nm。碳含量为3.5%,3.7%和4.3%的纳米结构白口铸铁的维氏硬度分别为552、577和575 HV,抗压强度为2224、2460和2220 MPa,抗拉强度为383、416和245 MP,均呈现先增大后减小的趋势;伸长率为3%、2.5%和1%,呈现逐渐下降的趋势。无昂贵合金元素添加的纳米结构白口铸铁的力学性能与Ni-Hard 2铸铁相当。

  17. Laser-MIG hybrid welding performance of spheroidal graphite cast iron and ferrite stainless steel%球墨铸铁和铁素体不锈钢的激光-MIG复合焊接性能

    Institute of Scientific and Technical Information of China (English)

    徐国建; 刘祥宇; 杭争翔; 邢飞; 石磊

    2012-01-01

    为了研究球墨铸铁(FCD450)和铁素体不锈钢(SUS430)的异种焊接性能,采用3种不同镍质量分数的焊丝对球墨铸铁和铁素体不锈钢进行激光-MIG复合焊接试验,并确定最佳焊接条件.通过光学显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDS)、电子探针(EPMA)和维氏硬度计对焊接接头的显微组织、成分分布及硬度分布进行分析,并对焊接接头进行拉伸试验.试验结果表明,在最佳焊接条件下,通过添加3种焊丝,焊接接头无裂纹出现且焊缝成型良好.由于焊丝的作用,焊缝金属铬和镍的质量分数较高.随着焊丝Ni质量分数的增加,焊缝宽度明显减小.由于莱氏体和马氏体的存在,拉伸试样都断在FCD450侧的半熔化区或热影响区.%In order to study the dissimilar welding performance of spheroidal graphite cast iron(FCD450) and ferrite stainless steel(SUS430),the laser-MIG hybrid welding tests for FCD450 and SUS430 were carried out through adopting three kinds of welding wires with different mass fraction of Ni,and the optimum welding condition was determined.The microstructure,constituent distribution and hardness distribution of welding joints were analyzed with optical microscope(OM),scanning electron microscope(SEM),energy dispersive spectrometer(EDS),electron probe microanalysis(EPMA) and Vicker's hardness tester.In addtion,the tensile tests were performed for the welding joints.The experimental results show that under the optimum welding condition,no crack is found in the welding joints and the welding performance is good with adding three kinds of welding wires.Due to the adoption of the welding wires,the mass fraction of Cr and Ni in the welding seam area is higher.With increasing the mass fraction of Ni in the welding wires,the width of welding seam obviously reduces.Due to the existence of ledeburite and martensite,the fracture of all tensile specimens occurs in the partial melting zone

  18. TX型方钢管相贯节点X支管平面内抗弯刚度分析%Analysis on In-plane Bending Stiffness of X Branch Pipe of TX-type Square Steel Tubular Joint

    Institute of Scientific and Technical Information of China (English)

    张婷婷; 夏军武; 陈婷; 王秋芬

    2012-01-01

    为了分析TX型方钢管相贯节点在复杂边界条件下X支管平面内抗弯刚度的影响,以相贯节点足尺试验为基础,采用量纲分析得到影响相贯节点抗弯刚度的主要无量纲参数,利用有限元软件分析X支管平面内抗弯刚度受主要无量纲参数的影响,并展开研究.试验表明:主管的轴向拉力可以略微提高X支管平面内抗弯刚度.通过分析几何因素对抗弯刚度的影响,结果表明:X支管平面内抗弯刚度主要取决于X支管与主管的宽度比和宽厚比.%In order to analyze the influence of in-plane bending stiffness of X branch pipe under complex boundary of spatial TX-type square steel tubular joint,we got dimensionless parameters which influence bending stiffness of tubular joint through dimensional analysis based on full-scale test of tubular joint.Meanwhile,we analyzed and studied main dimensionless parameters' influence on in-plane bending stiffness of X branch pipe using finite element software.The test shows that axial tension of the main tubular can slightly improve in-plane bending stiffness of X branch pipe.Through the analysis of geometrical factors' influence on bending stiffness,the result shows that in-plane bending stiffness of X branch pipe mainly depends on the width ratio of X branch to main tubular and width-thickness ratio of the main tubular.

  19. Study on cold tensile properties of polyethylene pipe fusion welded joint%聚乙烯管道热熔对接焊接头冷拉伸性能研究

    Institute of Scientific and Technical Information of China (English)

    黄学斌; 伏喜斌; 徐火力; 尤志轩; 阙小颖; 戴鸿滨

    2015-01-01

    Polyethylene pipe material and metal pipe material have great differences in the mechanical properties due to the two particle bonding to form different.The cold tensile properties are unique properties of polyethy-lene material.The paper analyzes the cold tensile phenomenon of polyethylene.The experiments conform that the cold tensile properties of butt fusion welding joint of polyethylene pipes make its tensile strength is superior to the base joint, fracture analysis verifies the presence of silver grain fracture.The formation of silver grains in-creases the toughness of polymer, so we can judge preliminarily the butt fusion welding joint quality of polyethy-lene pipe through the white area size of the fracture.%聚乙烯管道材料由于与金属管道材料质点间结合键构成不同,因此二者在力学性能上差异很大。冷拉伸性能是聚乙烯材料独有的特性。对聚乙烯冷拉伸现象进行了分析,通过试验发现聚乙烯管道热熔对接焊接头的拉伸强度要优于母材,母材颈缩出现“冷拉伸”现象。断口分析发现断口存在银纹,银纹的形成增加了聚合物的韧性,为此可通过断口白色区域的大小来初步判断聚乙烯管道热熔焊的接头质量。

  20. Composite drill pipe

    Science.gov (United States)

    Leslie, James C.; Leslie, II, James C.; Heard, James; Truong, Liem , Josephson; Marvin , Neubert; Hans

    2008-12-02

    A composite pipe segment is formed to include tapered in wall thickness ends that are each defined by opposed frustoconical surfaces conformed for self centering receipt and intimate bonding contact within an annular space between corresponding surfaces of a coaxially nested set of metal end pieces. The distal peripheries of the nested end pieces are then welded to each other and the sandwiched and bonded portions are radially pinned. The composite segment may include imbedded conductive leads and the axial end portions of the end pieces are shaped to form a threaded joint with the next pipe assembly that includes a contact ring in one pipe assembly pierced by a pointed contact in the other to connect the corresponding leads across the joint.

  1. Effect of carbon content on carbide morphology and mechanical properties of A.R. white cast iron with 10-12% tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, D. [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Skandani, A. Alipour [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States); Al Haik, M., E-mail: alhaik@vt.edu [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Effect of W and C variation in A.R. white cast iron was studied up to 12 wt% W. It never exceeded 10 wt% in previous investigations. Black-Right-Pointing-Pointer Carbide morphologies with 2.2-3.2 wt% carbon shows that W has dominating effect on carbide morphology. Black-Right-Pointing-Pointer New carbide microstructures (GA and IA) appear in some range of carbon and its volume fraction is function of carbon content. Black-Right-Pointing-Pointer After heat treatment, new carbide morphology turns to continuous chromium carbide. Black-Right-Pointing-Pointer Wear resistance and hardness of the new alloys depends on both IA appearance presence and tungsten carbide precipitation. - Abstract: Carbide morphologies of white cast iron containing 22% Cr and 10-12% tungsten with different carbon contents (2.34-3.20 wt.%) were investigated. Results indicated that for the as-cast alloys with no heat treatments, the addition of carbon changes the morphology of carbides during air-cooling in the presence of tungsten. Light microscopy analysis revealed that for an alloy with 2.3 wt% carbon, chromium carbides possess coarse gray appearance (GA). Increasing the carbon content reduced the coarse GA zones volume fraction while a finer GA zones emerged. The coexistence of coarse and fine GA phases came to an end at 2.8 wt% carbon, at which only fine GA zones spread throughout the chromium carbide phase. Scaling up the carbon content to 3.2 wt% led to the formation of tungsten carbide and austenite in a eutectic reaction. Both fine and coarse GA zones vanished while the tungsten carbides acquired fishbone-like morphology. Upon heat treatment, the coarse GA zones vanished completely and turned into island appearance (IA) of chromium carbide. On the contrary, the finer GA zones remained unchanged after heat treatment and they coexisted with the IA. After heat treatment, the fishbone morphology shattered apart, however, the hyper chromium carbides

  2. 高镍铸铁排气歧管低周热疲劳研究%Low Cycle Thermal Fatigue of High Nickel Cast Iron Exhaust Manifold

    Institute of Scientific and Technical Information of China (English)

    袁守利; 王超; 刘志恩; 李雪妮

    2014-01-01

    针对某新开发的车用高镍铸铁排气歧管进行了低周热疲劳寿命预测研究,为获取准确的热边界条件,采用STAR-CCM+与有限元软件进行基于疲劳寿命试验条件的非稳态耦合传热分析,得到了排气歧管的对流换热系数和温度场,建立了具有真实装配关系并施加螺栓预紧力的排气歧管有限元模型,在对等效塑性应变分析的基础上,结合Coffin-Manson公式进行寿命预测。结果表明,在排气歧管开发过程中,采用该方法可以快速对其热疲劳寿命进行评估。%The low cycle thermal fatigue life of a newly developed high nickel cast iron exhaust manifold for vehicle was pre -dicted.In order to obtain a more accurate thermal boundary condition , STAR-CCM+and FE software were applied to analyze non-steady coupled heat transfer based on fatigue life experiment .The convective heat transfer coefficient and temperature field of exhaust manifold were then obtained .The FE model of the exhaust manifold was established with accurate assembly relation a-mong different components and bolt pre -tightening loads .At last, using Coffin-Manson equation , life prediction was completed based on analysis of equivalent plastic strain .The result indicates that the analysis method could speed up thermal fatigue life prediction of an exhaust manifold during developing process .

  3. Effects of operational parameters and common ions on the reduction of 2,4-dinitrotoluene by scrap copper-modified cast iron.

    Science.gov (United States)

    Fan, Jin-Hong; Wang, Hong-Wu

    2015-07-01

    Scrap Cu-modified cast iron (CMCI) is a potent material for the reduction of 2,4-dinitrotoluene (2,4-DNT) by a surface-mediated reaction. However, the effects of operational parameters and common ions on its reduction and final rate are unknown. Results show that the 2,4-DNT reduction was significantly affected by Cu:Fe mass ratio and the optimum m(Cu:Fe) was 0.25%. The slight pH-dependent trend of 2,4-DNT reduction by CMCI was observed at pH 3 to 11, and the maximum end product, 2,4-diaminotoluene (2,4-DAT), was generated at pH 7. Dissolved oxygen (DO) in the water reduced the 2,4-DNT degradation and the formation of 2,4-DAT. CMCI effectively treated high concentrations of 2,4-DNT (60 to 150 mg L(-1)). In addition, varying the concentration of (NH4)2SO4 from 0.001 to 0.1 mol L(-1) improved the efficiency of the reduction process. The green rust-like corrosion products (GR-SO4 (2-)) were also effective for 2,4-DNT reduction, in which Na2CO3 (0.01 to 0.2 mol L(-1)) significantly inhibited this reduction. The repeated-use efficiency of CMCI was also inhibited. Moreover, 2,4-DNT and its products, such as 4A2NT, 2A4NT, and 2,4-DAT, produced mass imbalance (inhibition of CO3 (2-). The 2,4-DNT reduction by CMCI could be described by pseudo-first-order kinetics. The operational conditions and common ions affected the 2,4-DNT reduction and its products by enhancing the corrosion of iron or accumulating a passive oxide film on the reactivity sites. PMID:25663339

  4. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system.

    Science.gov (United States)

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-11-01

    In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography-Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better. PMID:27244696

  5. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system.

    Science.gov (United States)

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-11-01

    In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography-Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

  6. Evaluation of allowable external pressure for branch pipe connections

    International Nuclear Information System (INIS)

    Although the allowable external pressure for branch pipe connections is estimated by evaluation procedure for straight pipe, the applicability of this procedure has not been clear. That was discussed in this study. The buckling pressure of branch pipe connections was estimated by linear eigenvalue analysis with FEA (Finite Element Analysis). The types of branch pipe connections were T-joints and T-pipes. The ranges of configurations in branch pipe connections for FEA were determined by survey of branch pipe connections in the Japanese nuclear power plants. The results of the FEA showed that the buckling strength of branch pipe was found sufficiently to be superior to that of straight piping from comparisons of estimations by FEA for branch pipe connections and those by formula for straight pipe in the design code. It was concluded that the formula for straight pipe is applicable for the evaluation of allowable external pressure for branch pipe connections. (author)

  7. 49 CFR 192.277 - Ductile iron pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Ductile iron pipe. 192.277 Section 192.277 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Ductile iron pipe. (a) Ductile iron pipe may not be joined by threaded joints. (b) Ductile iron pipe...

  8. 46 CFR 56.75-30 - Pipe joining details.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Pipe joining details. 56.75-30 Section 56.75-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-30 Pipe joining details. (a) Silver brazing. (1) Circumferential pipe joints...

  9. Lightweight Exhaust Manifold and Exhaust Pipe Ducting for Internal Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1999-01-01

    An improved exhaust system for an internal combustion gasoline-and/or diesel-fueled engine includes an engine exhaust manifold which has been fabricated from carbon- carbon composite materials in operative association with an exhaust pipe ducting which has been fabricated from carbon-carbon composite materials. When compared to conventional steel. cast iron. or ceramic-lined iron paris. the use of carbon-carbon composite exhaust-gas manifolds and exhaust pipe ducting reduces the overall weight of the engine. which allows for improved acceleration and fuel efficiency: permits operation at higher temperatures without a loss of strength: reduces the "through-the wall" heat loss, which increases engine cycle and turbocharger efficiency and ensures faster "light-off" of catalytic converters: and, with an optional thermal reactor, reduces emission of major pollutants, i.e. hydrocarbons and carbon monoxide.

  10. 微波扫描法检测聚乙烯管道热熔接头缺陷初探%Microwave Scanning Inspection of Defects in Thermo-fusion Joints of Polyethylene Piping

    Institute of Scientific and Technical Information of China (English)

    祝新伟; 潘金平; 谭连江; 徐祥明; 沈美华; 李勇

    2013-01-01

    以聚乙烯管道热熔接头为检测对象,使用微波扫描的方法检测热熔接头中不同类型的缺陷.首先对无缺陷的热熔接头进行微波扫描检测,得到的扫描图像作为参考图像.然后对含有裂纹、冷焊等不同缺陷的聚乙烯管道热熔接头进行微波扫描检测,得到具有不同特征的扫描图像.对这些扫描图像进行分析可以判别缺陷的类型.最后,利用拉伸力学测试的结果,初步验证了微波扫描方法对聚乙烯管道热熔接头缺陷检测的有效性.%The method of microwave scanning was employed to detect different types of defects existing in the thermo - fusion joints of polyethylene ( PE) piping. Firstly the thermo - fusion joints without defects were inspected by microwave scanning,and the scanning images obtained were taken as the references. Then the thermo -fusion joints containing different defects including cracks,cold weld,etc. ,were inspected and the resultant scanning images corresponding to different defects were obtained. The types of the defects can be distinguished by analyzing the scanning images. At last, tensile tests for the thermo - fusion joints were performed to confirm the effectiveness of microwave scanning in detecting the defects in the thermo - fusion joints of PE piping.

  11. Effects of carbon and molybdenum on the microstructures of high chromium white cast irons; Efeito do carbono e do molibdenio na microestrutura dos ferros fundidos brancos de alto cromo

    Energy Technology Data Exchange (ETDEWEB)

    Sinatora, Amilton; Ambrosio Filho, Francisco; Goldenstein, Helio; Fuoco, Ricardo; Albertin, Eduardo; Mei, Paulo Roberto

    1992-12-31

    The effects of 3 levels of carbon and 1.5% Mo addition on the solidification structures of a 15% chromium white cast iron were studied. The volume fraction of primary austenite and of eutectic carbides, as well as the number of carbide particles per unit length and the mean secondary dendrite arm spacing were measured. By means of thermal analysis, thermal arrest corresponding to the formation of the primary austenite and of the eutectic were determined. The increase in the carbon content and the addition of Mo led to lowering of the thermal arrests and to coarsening of the particles. (author) 15 refs., 6 figs., 5 tabs.

  12. Effect of heat treatment on the wear and corrosion behaviors of a gray cast iron coated with a COLMONOY 88 alloy deposited by high velocity oxygen fuel (HVOF thermal spray

    Directory of Open Access Journals (Sweden)

    A. Öz

    2013-07-01

    Full Text Available The present work has been conducted in order to determine the influence of heat treatment on the wear and corrosion behaviours of a gray cast iron substrate coated with a Ni base coating deposited by HVOF thermal spray. The wear resistance of the coatings was obtained using a reciprocating wear tester by rubbing a 10 mm diameter steel ball on the coatings at normal atmospheric conditions. Corrosion tests were performed using potentiodynamic polarization measurements in a 3,5 % NaCl solution. It was observed that the corrosion and wear resistance of the coatings increased along with the reduction of porosity and roughness by the heat treatment.

  13. Determination of silicon and chromium content in gray cast iron by the Van der Pauw method; Determinacion del contenido de silicio y cromo en fundiciones grises mediante el metodo de Van der Pauw

    Energy Technology Data Exchange (ETDEWEB)

    Tremps, E.; Enrique, J. L.; Moron, C.; Garcia, A.; Gomez, A.

    2013-07-01

    In this paper we show a system based on the resistivity measurement of samples of gray cast iron by the Van der Pauw method to calculate the silicon content in the samples. Twenty five trials have been carried out, studying resistive and metallographic characteristics of the samples. This has demonstrated that it is possible to obtain, by this method, the silicon content in molten flat with low content of alloying elements, also the content of chromium in series smelters where the rate of silicon remains constant. (Author)

  14. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Science.gov (United States)

    2010-10-01

    ... Materials Other Than by Welding § 192.283 Plastic pipe: Qualifying joining procedures. (a) Heat fusion... for making plastic pipe joints by a heat fusion, solvent cement, or adhesive method, the...

  15. Influence of alloying on phase precipitation of high chromium cast iron%合金化对高铬铸铁相析出的影响

    Institute of Scientific and Technical Information of China (English)

    李秀兰; 周新军; 谢文玲; 马幼平

    2015-01-01

    The chromium alloy was prepared from 2.8wt%carbon and 31.0wt%chromium by the additions of trace multi-alloying elements ( Ti, Nb, V, Mo) .The existence forms of Ti , Nb, V in multicomponent system were studied by calculation from the alloy thermodynamic consideration .The effect of additions of alloy elements on carbides precipitation behavior of high chromium cast iron was investigated .The results show that Ti and Nb exist in the multi-alloying system in forms of TiC and NbC during solidification .V element exists mainly in alloy compounds ( VCr2 C2 ,VCrFe8 ) .The first precipitated high melted point particles ( TiC, NbC) during cooling can act as the heterogeneous nuclei of M7C3 carbides, As a result, the increase of nucleation rate results in refined M 7C3 carbides morphology.However,the addition of excess alloy elements weakens the roles of M 7 C3 carbides refinement .%添加多元微量合金元素V、Ti、Nb和Mo到2.8C-31Cr合金中制备多元铬系合金,从合金热力学析出角度,通过计算分析Ti、V、Nb在多元体系中的存在方式,探讨添加的合金元素对高铬铸铁凝固组织中碳化物析出的影响。结果表明,Ti和Nb在高铬铸铁凝固过程中主要形成TiC和NbC,V主要存在于合金化合物VCr2 C2和VCrFe8中。先析出的TiC和NbC能充当碳化物异质形核基底,增加形核率使组织细化。但添加过量的合金元素却削弱了对碳化物的细化作用。

  16. Emission of BTEX and PAHs from molding sands with furan cold setting resins containing different contents of free furfuryl alcohol during production of cast iron

    Directory of Open Access Journals (Sweden)

    Mariusz Holtzer

    2015-11-01

    Full Text Available At present, furan resin is the largest selling no-bake system of moulding sands. The most commonly used furan no-bake binders (FNB are condensation products of furfuryl alcohol (FA urea, formaldehyde and phenol. They are generally cured by exposure to organic sulfonic acids. FNB provide excellent mold and core strength, cure rapidly and allow the sand to be reclaimed at fairly high yields, generally 75%-80%, especially in applications where due allowance is made for the need to keep total sulfur content below 0.1%. However, due to probable carcinogenic properties of furfuryl alcohol, the EU Directive limits the content of this substance (in a monomer form in resin to 25%. The classification of furfuryl alcohol and the resulting furan resin products has changed from "harmful" to "toxic" by inhalation? The aim of this study was to determine the effect of free furfuryl alcohol content in the resin on the emission of harmful substances from the BTEX (Benzene Toluene Ethylbenzene & Xylene and PAHs (polycyclic aromatic hydrocarbon group exposed to high temperature and how it affects the emissions allowance of reclaimed sand in the matrix. Three resins from a leading manufacturer were examined, which contain a free furfuryl alcohol content of 71%-72%, about 50% and < 25%, respectively. The hardener for each resin was 65% aqueous solution of paratoluenesulfonic acid. Tests were carried out in semi-industrial conditions where liquid cast-iron was poured into sample sand mold at 1,350 ìC. The matrix of the studied sands was reclaimed in the amount of 0, 50%, 100%, respectively. With the increase of free furfuryl alcohol content, the volume of evolved gases decreased. For all resins the main component from the BTEX group dominating in the emitted gases was benzene; however toluene also appeared in the amount of a few percentages. In contrast, ethylbenzene and xylenes occurred only in the gases emitted from resin-bonded sands with the largest furfuryl

  17. Effect of powder reactivity on fabrication and properties of NiAl/Al{sub 2}O{sub 3} composite coated on cast iron using spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Beyhaghi, Maryam [Department of Metallurgical and Materials Engineering, Ferdowsi University of Mashhad, 91775-1111 Mashhad (Iran, Islamic Republic of); Kiani-Rashid, Ali-Reza, E-mail: kianirashid@um.ac.ir [Department of Metallurgical and Materials Engineering, Ferdowsi University of Mashhad, 91775-1111 Mashhad (Iran, Islamic Republic of); Kashefi, Mehrdad; Khaki, Jalil Vahdati [Department of Metallurgical and Materials Engineering, Ferdowsi University of Mashhad, 91775-1111 Mashhad (Iran, Islamic Republic of); Jonsson, Stefan [Department of Materials Science and Engineering, Royal institute of Technology, SE-10044 Stockholm (Sweden)

    2015-07-30

    Highlights: • Obtaining mechanically activated and reacted powders by different ball milling time of Ni, Al and NiO. • Fabrication of dense NiAl/Al{sub 2}O{sub 3} composite coatings by spark plasma sintering of both reacted and reactive powder mixtures. • Investigation on phase evolution in diffusion bond layer at coating-substrate interface of samples. • Study on influence of powder ball milling time on microstructure, Vickers hardness and scratch hardness of coatings. • Achieving good adhesion of coating to substrate and clean interface between substrate and coating in samples. - Abstract: Powder mixtures of Ni, NiO and Al are ball milled for 1 and 10 h. X-ray diffractometry and differential thermal analysis show that while ball milling for 1 h produced mechanically activated powder; 10 h ball milling produced NiAl and Al{sub 2}O{sub 3} phases. Dense NiAl/Al{sub 2}O{sub 3} composite coatings are formed on gray cast iron substrate by spark plasma sintering (SPS) technique. The effect of powder reactivity on microstructure, hardness and scratch hardness of NiAl/Al{sub 2}O{sub 3} coatings after SPS is discussed. Results show that in the coating sample made of mechanically activated powder in situ synthesis of NiAl/Al{sub 2}O{sub 3} composite coating is fulfilled and a thicker well-formed diffusion bond layer at the interface between coating and substrate is observed. The diffusion of elements across the bond layers and phase evolution in the bond layers were investigated. No pores or cracks were observed at the interface between coating layer and substrate in any of samples. Higher Vickers hardness and scratch hardness values in coating made of 10 h ball milled powder than in coating fabricated from 1 h ball milled powder are attributed to better dispersion of Al{sub 2}O{sub 3} reinforcement particles in NiAl matrix and nano-crystalline structure of NiAl matrix. Scratched surface of coatings did not reveal any cracking or spallation at coating

  18. Comprehensive study of the abrasive wear and slurry erosion behavior of an expanded system of high chromium cast iron and microstructural modification for enhanced wear resistance

    Science.gov (United States)

    Chung, Reinaldo Javier

    High chromium cast irons (HCCIs) have been demonstrated to be an effective material for a wide range of applications in aggressive environments, where resistances to abrasion, erosion and erosion-corrosion are required. For instance, machinery and facilities used in mining and extraction in Alberta's oil sands suffer from erosion and erosion-corrosion caused by silica-containing slurries, which create challenges for the reliability and maintenance of slurry pumping systems as well as other processing and handling equipment. Considerable efforts have been made to determine and understand the relationship between microstructural features of the HCCIs and their wear performance, in order to guide the material selection and development for specific service conditions with optimal performance. The focus was previously put on a narrow group of compositions dictated by ASTM A532. However, with recent advances in casting technology, the HCCI compositional range can be significantly expanded, which potentially brings new alloys that can be superior to those which are currently employed. This work consists of three main aspects of study. The first one is the investigation of an expanded system of white irons with their composition ranging from 1 to 6 wt.% C and 5 to 45 wt.% Cr, covering 53 alloys. This work has generated wear and corrosion maps and established correlation between the performance and microstructural features for the alloys. The work was conducted in collaboration with the Materials Development Center of Weir Minerals in Australia, and the results have been collected in a database that is used by the company to guide materials selection for slurry pump components in Alberta oil sands and in other mining operations throughout the world. The second part consists of three case studies on effects of high chromium and high carbon, respectively, on the performance of the HCCIs. The third aspect is the development of an approach to enhance the wear resistance of

  19. 螺旋埋弧焊管预精焊焊接接头性能分析%Analysis on Welded Joint Performance of Two-step Welding SAWH Pipe

    Institute of Scientific and Technical Information of China (English)

    李建一; 田鹏; 孙志刚; 韩景伟; 祁超

    2011-01-01

    This article introduced production process of two-step welding, statistically analyzed test results of X70 cf> 1 016 mmxl7.5 mm SAWH pipe welded joints, such as tensile test, Charpy impact test and Vickers hardness test, and compared two-step welding process with traditional one-step welding process. The results indicated that welded joint tensile strength of the two-step welding process is basic equivalent to that of traditional one-step welding process, the Charpy impact toughness and Vickers hardness are better than those of the one-step method weld joint The comprehensive mechanical properties of welded joints are good, which can meet the requirements of the technical specification of X70 SAWH line pipe for the 2nd West-east Pipeline Project.%介绍了螺旋埋弧焊管预精焊生产工艺,对预精焊工艺生产X70钢级φ1 016 mm×17.5 mm螺旋埋弧焊管焊接接头拉伸试验、夏比冲击试验、维氏硬度试验等试验结果进行了统计分析,并与传统的一步法工艺进行了对比.结果表明,预精焊生产工艺焊接接头抗拉强度与一步法工艺基本相当,夏比冲击韧性、维氏硬度等性能略优于一步法工艺,综合力学性能良好,满足《西气东输二线管道工程用X70螺旋缝埋弧焊管技术条件》要求.

  20. AD24井?139.7mm钻杆接头断裂分析%Rupture Analysis of ?139.7 mm Drill Pipe Joints in AD24 Well

    Institute of Scientific and Technical Information of China (English)

    易浩; 吕庆钢; 陈勇; 刘志良; 张胜鹏; 雷正义

    2011-01-01

    采用有限元技术分析了AD24井?139.7 mm钻杆断裂失效的原因,利用测量统计结果得出双台肩钻杆接头承载能力大幅下降是钻杆接头产生疲劳断裂的主要原因,为采取相关的预防措施提供了理论依据.%The 0139. 7 mm pipes were used to drill in AD24 well,crack happened on 39 pipes. With a large proportion of rupture,it had inherent reasons. Therefore, finite element technique was a-dopted to quantitatively analyzing the reasons of the failure,in order to take corresponding prevention measures to provide theoretical basis. Moreover measuring statistical results were used and bearing capacity decreasing of double shoulder pipe joints was the main reason of fatigue fracture.

  1. Graphitization in chromium cast iron

    OpenAIRE

    LECOMTE-BECKERS, Jacqueline; Terziev, L.; Breyer, J. P.

    1998-01-01

    Some trials with graphite Hi-Cr iron rolls have been done mainly in Japan, for the rolling of stainless steel. This material could lead to good compromise between oxidation, wear and thermal behaviour. By using thermal analysis and resistometry, the conditions for secondary graphite formation have been studied. The amount and volume of free graphite may be strongly increased by a suitable heat treatment, allowing a good thermal conductivity as well as high wear and mechanical properties.

  2. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang

    2009-01-01

    @@ Grey Iron(Ⅲ) 2.5 Crystallization of the LTF during final stage of eutectic solidification of grey iron In the final stage of eutectic solidification, eutectic cells grow gradually into large sizes; the liquid iron between the cells enters the last stage of solidification. At this time, the region of the remaining liquid iron is called last to freeze volume, LTF in short, as shown in Fig.2-39.

  3. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    By Zhou Jiyang; Professor

    2011-01-01

    5.5 Eutectic crystallisation of white iron When undercooled below the eutectic line ECF in the Fe-C phase diagram,liquid iron will start eutectic transformation (crystallization):eutectic liquid → cementite + austenite.Eutectic crystallisation is an important stage during the crystallization of white iron.At this stage,the nucleation and growth of eutectic cells (consisting of carbide or cementite + austenite) occur.The carbide in eutectic cells (or eutectic carbide) is the main hard and brittle phase structure which has an important effect on the properties of white iron.If there is no primary carbide in the structure,the effect of eutectic carbide is more prominent.5.5.1 Thermodynamics and kinetics of eutectic crystallisationWhether a eutectic melt follows the meta-stable system to crystallise as carbide + austenite,or follows the stable system to crystallise as graphite + austenite eutectic,is dependent on the nucleation and growth of the two high carbon phases (carbide and graphite),namely,on thermodynamic and kinetic conditions.Figure 5-23 shows the comparison of thermodynamic driving forces of the two eutectics.The two lines in the lower section of the figure represent the free energy of the two eutectics respectively and GL is the free energy of the undercooled iron melt.It is easy to see that the iron melt has the highest free energy and the graphiteaustenite has the lowest free energy;so,following a stable system,the thermodynamic condition favours the crystallisation of graphite-austenite eutectic from the iron melt.

  4. 烧碱浓度及冲刷对合金铸铁耐碱腐蚀性能的影响%Effect of Dentist and Scouring on Soda Corrosion Resistance of RE-Ni-Cu Alloy Cast Iron

    Institute of Scientific and Technical Information of China (English)

    张毅; 董俊慧

    2011-01-01

    采用失重法测定稀土镍铜合金铸铁在不同浓度烧碱液中以及静、动态下的腐蚀速度.结果表明,随着浓度的升高,稀土镍铜合金铸铁的腐蚀速度加快,而适量的稀土含量可降低合金铸铁对浓度的敏感性.碱液的冲刷会加剧稀土镍铜合金铸铁的腐蚀.%The corrosion rate of RE-Ni-Cu alloy cast irons was tested in soda solution at different dentist and static and dynamic condition. Experimental results show that the corrosion rate is accelerated as dentist raising. However, the proper content of RE can reduce the sensitivity on dentist. The soda solution scouring aggravates the corrosion of the alloy cast iron.

  5. Effects of Heat Treatment on Hardness and Dry Wear Properties of a Semi-Solid Processed Fe-27 wt pct Cr-2.9 wt pct C Cast Iron

    Institute of Scientific and Technical Information of China (English)

    A. Wiengmoon; T. Chairuangsri; N. Chomsang; N. Poolthong; J.T.H. Pearce

    2008-01-01

    Effects of heat treatments on hardness and dry wear properties of a semi-solid processed Fe-26.96 wt pct Cr- 2.91 wt pct C cast iron were studied. Heat treatments included tempering at 500℃, destabilisation at 1075℃ and destabilisation at 1075℃ plus tempering at 500℃, all followed by air cooling. Electron microscopy revealed that, in the as-cast condition, the primary proeutectic austenite was round in shape while the eutectic M7C3 carbide was found as radiating clusters mixed with directional clusters. Tempering did not change the microstructure significantly when observed by scanning or transmission electron microscopy. Destabilisation followed by air cooling led to a precipitation of secondary M23C6 carbide and a transformation of the primary austenite to martensite. Precipitation behaviour is comparable to that observed in the conventionally cast iron. Tempering after destabilisation resulted in a higher amount of secondary carbide precipitation within the tempered martensite in the eutectic structure. Vickers macrohardness and microhardness in the proeutectic zones were measured. Dry wear properties were tested by using a pin-on-disc method. The maximum hardness and the lowest dry wear rate were obtained from the destabilisation-plus-tempering heat treatment due to the precipitation of secondary carbides within the martensite matrix and a possible reduction in the retained austenite.

  6. Development of a iron pipe corrosion simulation model for a water supply network

    Directory of Open Access Journals (Sweden)

    M. Bernats

    2012-04-01

    Full Text Available Corrosion in water supply networks is unwanted process that causes pipe material loss and subsequent pipe failures. Nowadays pipe replacing strategy most often is based on pipe age, which is not always the most important factor in pipe burst rate. In this study a methodology for developing a mathematical model to predict the decrease of pipe thickness in a large cast iron networks is presented. The quality of water, the temperature and the water flow regime were the main factors taken into account in the corrosion model. The water quality and flow rate effect were determined by measuring corrosion rate of metals coupons over the period of one year at different flow regimes. The obtained constants were then introduced in a calibrated hydraulic model (Epanet and the corrosion model was validated by measuring the decrease of wall thickness in the samples that were removed during the regular pipe replacing event. The validated model was run for 30 yr to simulate the water distribution system of Riga (Latvia. Corrosion rate in the first year was 8.0–9.5 times greater than in all the forthcoming years, an average decrease of pipe wall depth being 0.013/0.016 mm per year in long term. The optimal iron pipe exploitation period was concluded to be 30–35 yr (for pipe wall depth 5.50 mm and metal density 7.5 m3 t−1. The initial corrosion model and measurement error was 33%. After the validation of the model the error was reduced to below 15%.

  7. Analysis on Welded Joint Properties of X1O0 SAWL Pipe%X100直缝埋弧焊管焊接接头性能分析

    Institute of Scientific and Technical Information of China (English)

    石威; 吉玲康; 胡莎莎

    2013-01-01

    With increasing needs of SAWL pipe, the analysis and research of SAWL pipe performance properties is very important In this paper,the X100 SAWL pipe produced by a foreign steel plant was carried out a series of analysis, including tensile, impact toughness and hardness tests for base metal and welded joint , combined with metallographic analysis, integrated assessment for microstructure and properties of steel was conducted. The results showed that the ensile strength of SAWL pipe welded joints is close to that of base metal, the microhardness of weld metal is higher than that of base metal, and the micro-hardness in HAZ is lower than that of base metal- The submerged arc weld metal is with good toughness, the ductile-brittle transition temperature is-60~-50℃, and the ductile-brittle transition temperature in HAZ is-30~-20 ℃.%随着直缝埋弧焊钢管需求的不断加大,分析和研究直缝埋弧焊管各项性能指标显得尤为重要.本研究对国外某钢厂生产的X100直缝埋弧焊管进行了一系列分析,对母材和焊接接头进行了拉伸、冲击韧性和显微硬度等试验,结合金相组织分析,综合评定该钢组织性能.结果表明,直缝埋弧焊管焊接接头抗拉强度接近母材,焊缝金属的显微硬度高于母材,热影响区显微硬度低于母材;埋弧焊焊缝金属的韧性良好,韧脆转变温度为-60~-50℃,热影响区韧脆转变温度为-30~-20℃.

  8. The Impact Of the Welded Joints Made Of X8CrNiTi18–10 Stainless Steel on the Reliability Estimation of Pipes

    Directory of Open Access Journals (Sweden)

    Raimondas Skindaras

    2011-02-01

    Full Text Available The chrome-nickel stainless steels of austenitic class applied in chemistry and energy industry are often used in the production of exceptional structures employed in an environment aggressive and dangerous for human life. Therefore, it is particularly significant for durability and reliability requirements. The article explores cracks that appeared in a tube made of X8CrNiTi18–10 austenitic steel. The examined pipe has worked for 90 000 hours under high temperature and pressure in an aggressive media. To establish reasons for developed cracks, chemical composition, strength, hardness testing and metallographic structures have been examined. The performed investigations will prevent from potential emergencies and help with a more accurate assessment of the pipes made of particularly this class of steel in order to ensure operational reliability and durability in the future.Article in Lithuanian

  9. The Impact Of the Welded Joints Made Of X8CrNiTi18–10 Stainless Steel on the Reliability Estimation of Pipes

    OpenAIRE

    Raimondas Skindaras; Jonas Bendikas; Vigantas Kumšlytis

    2011-01-01

    The chrome-nickel stainless steels of austenitic class applied in chemistry and energy industry are often used in the production of exceptional structures employed in an environment aggressive and dangerous for human life. Therefore, it is particularly significant for durability and reliability requirements. The article explores cracks that appeared in a tube made of X8CrNiTi18–10 austenitic steel. The examined pipe has worked for 90 000 hours under high temperature and pressure in an aggress...

  10. L415+316L机械复合管焊接接头失效分析%Failure Analysis on Welded Joint of L415+316L Mechanical Composite Pipe

    Institute of Scientific and Technical Information of China (English)

    张城举; 李霄; 牛辉; 赵海鸿; 靳海城

    2016-01-01

    为了减少油田L415+316L复合管环焊接头在水压、运行过程中的失效现象,利用硬度测试、组织分析、弯曲试验、断口形貌分析等方法对开裂的焊接接头进行试验研究。分析发现,由于封焊层、过渡层是高合金钢与碳钢之间的焊接,焊缝易因增碳造成硬度偏高,从而导致韧性降低; R309L封焊层、 R309LMo过渡层焊缝的断口均呈现准解离状态,为脆性断裂,焊接接头的封焊层因承受较高应力集中而产生裂纹,且裂纹沿轴线方向扩展。分析得出的复合焊管焊接接头开裂原因,可为复合管设计者改进设计提供参考。%In order to reduce the failure phenomenon occurred in hydraulic pressure and operation course of L415+316L composite pipe circumferential welded joint, the cracked welded joint was analyzed by hardness test, microstructure analysis, bending test and fracture morphology. The results showed that because of the sealing layer, transition layer are welded by high alloy steel and carbon steel, the weld recarburization easily causes high hardness, thus lead to lower toughness. The R309L sealing layer and the weld fracture of R309LMo transition layer show a quasi-dissociation state, it is brittle fracture. The sealing layer of welded joint generate cracks because of bearing high stress concentration, and extend along the axis direction. Finally, the cracking reasons of composite pipe welded joint were obtained, which can be used as the reference for the designer to improve design.

  11. Production Study on Hard Chromium Plating Technology for Chilled Cast Iron Piston Rod%冷硬铸铁活塞杆电镀硬铬工艺生产研究

    Institute of Scientific and Technical Information of China (English)

    陈贵清; 陈小刚

    2013-01-01

    Production technology of composite ductile cast iron production machine with a hydraulic piston rod of hard chromium electroplating was researched.The electroplating solution and electroplating parameters from the casting to the electroplating process were designed.The quality of piston rod of hard chromium electroplating improves,the quality stability of hard chromium electroplating can be effectively controlled.%通过对复合球墨冷硬铸铁生产的液压机活塞杆电镀硬铬生产工艺技术的研究,设计了从铸造到电镀整个过程的电镀前处理工艺方案及电镀工艺参数.用此工艺可提高活塞杆电镀硬铬的质量,有效地控制了电镀硬铬质量的稳定性.

  12. Development of the white cast iron with niobium alloy, heat treating, to wear of the abrasive resistance; Desenvolvimento de uma liga de ferro fundido branco alto cromo com niobio, tratada termicamente, para resistencia ao desgaste abrasivo

    Energy Technology Data Exchange (ETDEWEB)

    Farah, Alessandro Fraga

    1997-07-01

    This work presents the heat treatment and abrasion tests results of a white cast iron with niobium alloy. The hardening heat treatment were made 950, 1000, 1050 e 110 deg C temperatures cooled by forced air. The tempering treatment were made at 450, 500 e 550 deg C temperatures. The heat treating alloy were compared, in the abrasive tests, with commercial alloys used as hardfacing by welding process in wear pieces. The abrasion tests was realized in pin on disk test. Additional tests were carried out for microstructural characterization to identify the different phases presents in the alloys. In a general way, the alloy studies showed the best wear rate for the heat treatments that results in higher hardness. It performance was superior than that of the commercial alloys. (author)

  13. A galvanic corrosion study of brass/stainless steel and brass/cast iron couples; Estudio de corrosion galvanica en pares laton/acero inoxidable y laton/fundicion de hierro

    Energy Technology Data Exchange (ETDEWEB)

    Ohanian, M.; Diaz, V.; Corengia, M.; Zinola, C. F.

    2011-07-01

    Corrosion attack in heat exchanger systems is a topic of main interest for the maintenance in each industrial plant. These are multi galvanic systems with particular geometric and fluidodynamic complexity. Corrosive damages include zinc selective dealeation in copper alloys. In order to explain zinc dealeation attack, this paper deals with laboratory scale testing, characterization and interactions between two copper and zinc alloys (Yellow brass UNS C268 and Admiralty brass UNS C443) compared to AISI 316 stainless steel and cast iron. The tests were performed at 20 degree centigrade in 1.5 % NaCl and 1.5 % Na{sub 2}SO{sub 4} solutions, pH 8 and each material was characterized by potentiodynamic sweeps. The couples are analyzed by studying transient galvanic currents. We conclude about the cause of the analyzed pathology, brass protection potential ranges and its coupling compatibility with other metals. (Author) 33 refs.

  14. Reinforcement of Existing Cast-Iron Structural Elements by Means of Fiber Reinforced Composites / Wzmacnianie Istniejących, Żeliwnych Elementów Konstrukcyjnych za Pomocą Włóknokompozytów

    Directory of Open Access Journals (Sweden)

    Marcinowski Jakub

    2016-03-01

    Full Text Available The paperdeals with tubular, cast-iron columns which should be reinforced due to the planned new structural function of these elements. According to the requirements of the monument conservator the general appearance of columns should not be altered significantly. Reinforcement with an external, thin coating (sleeve or jacket made of composite (carbon fibre reinforced polymer - CFRP was proposed. Details of the proposedtechniquewerepresented. The reinforcementeffect was verifiedin destructivetestsperformed on two columns without reinforcement and the two other columns reinforced with the chosentechnique. Due to the expected very high load capacity of the axially loaded column, the test rig was designed in such a manner that the force could be applied on big eccentricity. For this purpose a specialbase was prepared(comp. Fig. 1. Destructivetests have confirmed the high effectiveness of the adopted strengthening technique.

  15. Reinforcement of Existing Cast-Iron Structural Elements by Means of Fiber Reinforced Composites / Wzmacnianie Istniejących, Żeliwnych Elementów Konstrukcyjnych za Pomocą Włóknokompozytów

    Science.gov (United States)

    Marcinowski, Jakub; Różycki, Zbigniew

    2016-03-01

    The paperdeals with tubular, cast-iron columns which should be reinforced due to the planned new structural function of these elements. According to the requirements of the monument conservator the general appearance of columns should not be altered significantly. Reinforcement with an external, thin coating (sleeve or jacket) made of composite (carbon fibre reinforced polymer - CFRP) was proposed. Details of the proposedtechniquewerepresented. The reinforcementeffect was verifiedin destructivetestsperformed on two columns without reinforcement and the two other columns reinforced with the chosentechnique. Due to the expected very high load capacity of the axially loaded column, the test rig was designed in such a manner that the force could be applied on big eccentricity. For this purpose a specialbase was prepared(comp. Fig. 1). Destructivetests have confirmed the high effectiveness of the adopted strengthening technique.

  16. Microstructure and Properties of Chromium Wear-resisting Cast Irons Used on Bimetallic Hammerhead%双金属复合锤头中铬系耐磨铸铁组织与性能

    Institute of Scientific and Technical Information of China (English)

    郭莹

    2011-01-01

    For the features of the high demand in strength and toughness of ore crusher hammer, this paper studied the structures and performances of wear-resistant chromium cast irons with different components. The experimental results showed that when the alloying element contents were 1.5% C, 9% Cr, 1.1% Si, 1.3% Mn, 1.3% Mo and 1.5% Cu, it would be in the impact toughness of 8.2 J/cm2 and the hardness of 58 HRC at the same time by appropriate quenching technology, this chromium cast iron can ensure adequate wear resistance in the premise of good strength and toughness(impact strength).%针对矿石破碎机锤头强韧性要求高的特点,研究合金元素对铬系耐磨铸铁组织和性能的影响。实验证明,当合金成分ω为1.5%C、9%Cr、1.1%Si、1.3%Mn、1.3%Mo和1.5%Cu时,通过适当的淬火工艺,可获得冲击韧度达到8.2 J/cm2、硬度达58 HRC的铬系耐磨铸铁材质,在保证足够的耐磨性前提下,具有良好的强韧性。

  17. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1994-01-01

    It is approximately 10 years since the Third Edition of Heat Pipes was published and the text is now established as the standard work on the subject. This new edition has been extensively updated, with revisions to most chapters. The introduction of new working fluids and extended life test data have been taken into account in chapter 3. A number of new types of heat pipes have become popular, and others have proved less effective. This is reflected in the contents of chapter 5. Heat pipes are employed in a wide range of applications, including electronics cooling, diecasting and injection mo

  18. 46 CFR 56.30-40 - Flexible pipe couplings of the compression or slip-on type.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Flexible pipe couplings of the compression or slip-on...) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Selection and Limitations of Piping Joints § 56.30-40 Flexible pipe couplings of the compression or slip-on type. (a) Flexible pipe couplings of the...

  19. X80埋弧焊管焊接接头冲击韧性数值研究%Numerical Simulation of Welding Joints Impact Toughness for X80 Submerged Arc Welded Pipe

    Institute of Scientific and Technical Information of China (English)

    张建勋; 杨中娜; 熊庆人; 郑莉

    2011-01-01

    Aim at impact toughness of submerged arc welded pipe welding joints, it predicted HAZ structure of submerged arc welding through CCT chart and temperature field,determined HAZ mechanical property combined with microhardness,established entity model in impact test by using finite element dynamic analysis software ANSYS/LS -DYNA,and carried out numerical simulation for dynamic impact procedure of welding joints. The absorbed energies which groove located in weld,HAZ and base metal were calculated separately. It also analyzed the variation of impaet toughness.%针对管线钢埋弧焊焊接接头的冲击韧性问题,采用CCT图和温度场结合法预测了埋弧焊接HAZ组织,结合显微硬度确定了HAZ力学性能,利用有限元法ANSY/LS-DYNA显式动力学分析软件,建立了冲击试验过程的实体模型,并对焊接接头动态冲击过程进行了数值模拟.分别计算了缺口位于焊缝、HAZ以及母材时的冲击过程中的吸收功,分析了冲击韧性的变化.

  20. A theoretical study of the fundamental torsional wave in buried pipes for pipeline condition assessment and monitoring

    Science.gov (United States)

    Muggleton, J. M.; Kalkowski, M.; Gao, Y.; Rustighi, E.

    2016-07-01

    Waves that propagate at low frequencies in buried pipes are of considerable interest in a variety of practical scenarios, for example leak detection, remote pipe detection, and pipeline condition assessment and monitoring. Whilst there has been considerable research and commercial attention on the accurate location of pipe leakage for many years, the various causes of pipe failures and their identification, have not been well documented; moreover, there are still a number of gaps in the existing knowledge. Previous work has focused on two of the three axisymmetric wavetypes that can propagate: the s=1, fluid-dominated wave; and the s=2, shell-dominated wave. In this paper, the third axisymmetric wavetype, the s=0 torsional wave, is investigated. The effects of the surrounding soil on the characteristics of wave propagation and attenuation are analysed for a compact pipe/soil interface for which there is no relative motion between the pipe wall and the surrounding soil. An analytical dispersion relationship is derived for the torsional wavenumber from which both the wavespeed and wave attenuation can be obtained. How torsional waves can subsequently radiate to the ground surface is then investigated. Analytical expressions are derived for the ground surface displacement above the pipe resulting from torsional wave motion within the pipe wall. A numerical model is also included, primarily in order to validate some of the assumptions made whilst developing the analytical solutions, but also so that some comparison in the results may be made. Example results are presented for both a cast iron pipe and an MDPE pipe buried in two typical soil types.