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Microstructure in the Weld Metal of Austenitic-Pearlitic Dissimilar Steels and Diffusion of Element in the Fusion Zone

Yajiang LI,Zengda ZOU,Bing ZHOU,

材料科学技术学报 , 2001,
Abstract: Microstructure and alloy element distribution in the welded joint between austenitic stainless steel (1Cr18Ni9Ti) and pearlitic heat-resistant steel (1Cr5Mo) were researched by means of light microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Microstructure, divisions of the fusion zone and elemental diffusion distributions in the welded joints were investigated. Furthermore, solidification microstructure and S-ferrite distribution in the weld metal of these steels are also discussed.
Study on Corrosion Behavior of Pearlitic Rail Steel  [PDF]
S. Samal, A. Bhattaacharyya, S.K. Mitra
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2011, DOI: 10.4236/jmmce.2011.107044
Abstract: The present study is an attempt to find out the effect of environmental corrosion on the commonly used pearlitic rail steel. The cases of corrosion of rail under Indian environment have been studied. It has been found that in marine environment both the yield strength and tensile strength decreases with increasing corrosion rate. In acidic environment yield strength increased with increasing corrosion rate, although the tensile strength decreases with increasing corrosion rate.
Continuous Wave Diode Laser Surface Texturing of Austenitic and Pearlitic Steels  [PDF]
Sulthan Mohiddin Shariff, Suresh Koppoju, Tapan Kumar Pal, Padmanabham Gadhe, Shrikant Viswanath Joshi
Materials Sciences and Applications (MSA) , 2015, DOI: 10.4236/msa.2015.610091
Abstract: Microstructuring of steel resulting in directional solidification and texturing, previously observed in various metallic materials during pulsed laser processing, melt-spinning, high-gradient liquid metal melting, zone melting etc., is reported for the first time in continuous wave diode laser processing of steels. Influence of laser interaction time on surface morphology/topology of austenitic manganese and pearlitic steels is investigated utilizing a wide rectangular multi-mode diode laser beam. X-ray diffraction analysis of the laser treated austenitic steel surface showed strong texturing influence, with preferred crystallographic orientation of γ-Fe crystals in the (200) plane, which increased with interaction time. In case of pearlitic steel, no such texturing influence could be observed. The free surface topologies were also observed to be different in each case, with well-aligned domes of γ-Fe observed in laser treated austenitic steel as compared to randomly oriented fine domes of metal oxides in pearlitic one. In situ surface temperature measurement during laser irradiation indicated higher temperature on pearlitic steel than in austenitic manganese steel owing to its lower effective thermal conductivity associated with higher oxide film formation.
放热焊接钢轨温度分布及预热保温研究
Research on temperature distribution, preheating and heat preservation of rail under exothermic welding
 [PDF]

黄尊地,常宁,冯振富,余启智
HUANG Zundi
,CHANG Ning,FENG Zhenfu,YU Qizhi

- , 2016,
Abstract: 轨道交通线路施工过程中,有很多导线接头需要焊接在钢轨上。放热焊接时温度处理不好导致钢轨中马氏体的存在,使钢轨结构脆化以及韧性变差,影响行车安全。通过试验和仿真对比验证分析,建立钢轨有限元计算模型,从不同的预热工况下分析焊接钢轨的温度分布情况以及马氏体温度点的影响范围,最后提出放热焊接钢轨的预热和保温措施,为轨道交通线路现场施工提供理论依据。
In the construction process of Rail transit lines, a lot of wire connectors will be welded on the rail. When heat treatment can not be handled properly, Martensite will exist in the rail, and that will make the rail structure embrittlement and poor toughness. At last, it will affect the safety of the vehicle. In this paper, experiment and simulation analysis are compared for mutual proof. After finite element model of rail has been built, temperature distribution of welded rail and the influence range of Martensite temperature point are got from different preheating condition. In this paper, the exothermic welding rail preheating and heat preservation measures are proposed. These findings can provide a theoretical basis for the rail transit line construction
Micro-and macro-analysis of the fatigue crack growth in pearlitic steels
Toribio,Jesús; González,Beatriz; Matos,Juan-Carlos;
Ciência & Tecnologia dos Materiais , 2008,
Abstract: this paper deals with the influence of the manufacturing process on the fatigue behaviour of pearlitic steels with different degrees of cold drawing. the analysis is focussed on the region ii (paris) of the fatigue behaviour in which da/dn=c (?k)m, measuring the constants (c and m) for the different degrees of drawing. from the engineering point of view, the manufacturing process by cold drawing improves the fatigue behaviour of the steels, since the fatigue crack growth rate decreases as the strain hardening level in the material increases. in particular, the coefficient m (slope of the paris laws) remains almost constant and independent of the drawing degree, whereas the constant c decreases as the drawing degree rises. the paper focuses on the relationship between the pearlitic microstructure of the steels (progressively oriented as a consequence of the manufacturing process by cold drawing) and the macroscopic fatigue behaviour. it is seen that the fatigue crack growth path presents certain roughness at the microscopic level, such a roughness being related to the pearlitic colony boundaries more than to the ferrite/cementite lamellae interfaces.
Micro-and macro-analysis of the fatigue crack growth in pearlitic steels  [cached]
Jesús Toribio,Beatriz González,Juan-Carlos Matos
Ciência & Tecnologia dos Materiais , 2008,
Abstract: This paper deals with the influence of the manufacturing process on the fatigue behaviour of pearlitic steels with different degrees of cold drawing. The analysis is focussed on the region II (Paris) of the fatigue behaviour in which da/dN=C ( K)m, measuring the constants (C and m) for the different degrees of drawing. From the engineering point of view, the manufacturing process by cold drawing improves the fatigue behaviour of the steels, since the fatigue crack growth rate decreases as the strain hardening level in the material increases. In particular, the coefficient m (slope of the Paris laws) remains almost constant and independent of the drawing degree, whereas the constant C decreases as the drawing degree rises. The paper focuses on the relationship between the pearlitic microstructure of the steels (progressively oriented as a consequence of the manufacturing process by cold drawing) and the macroscopic fatigue behaviour. It is seen that the fatigue crack growth path presents certain roughness at the microscopic level, such a roughness being related to the pearlitic colony boundaries more than to the ferrite/cementite lamellae interfaces. Este artigo trata da influencia do processo de fabrica ao no comportamento da fatiga de a os perliticos com graus diferentes de trefilado. A análise é centrada na regi o II (Paris) do comportamento da fatiga na que da/dN=C( K)m, medindo as constantes (C e m) para os diferentes graus do proceso de fabrica ao. Desde o ponto da vista da engenharia, o processo de fabrica ao polo desenho en frio melhora o comportamento da fatiga dos a os, dende que a taxa de crescimento da fissura da fatiga diminui enquanto aumenta o nível de endurescemento por deforma ao do material. No detalhe, o coeficiente m (inclina o das leis de Paris) permanesce quase constante e independente do grau de trefilado, mentras que a constante C diminui enquanto o grau de trefilado se levanta. O artigo focalizase no relacionamento entre a microstructura perlitica dos a os (orientados progressivamente em consequência do processo de fabrica ao pelo desenho en frio) e o comportamento macroscópico da fatiga. Vê-se que o trajeto do crescimento da fissura da fatiga apresenta determinada aspereza no nível microscópico, tal aspereza está sendo relacionada aos limites da col nia perlítica mais do que puideran influir as intercaras das lamellas de ferrita/cementita.
Toughness of welded stainless steels sheets for automotive industry  [PDF]
E. Bayraktar,D. Katundi,B.S. Yilbas,J. Claeys
Journal of Achievements in Materials and Manufacturing Engineering , 2011,
Abstract: Purpose: In the automotive industry, more and more it is compulsory to develop new grades of stainless steels, such as high resistant Martensitic Stainless Steels (MA-SS) and Ferritic Stainless Steels (FSS) in order to realise certain or many complex deep drawn pieces. For these grades, resistance spot welding (RSW) is the most widespread process used largely for many parts of the car body in the automotive industry. This paper aims to characterise mechanical behaviour (toughness) of the different steel grades under dynamic test conditions.Design/methodology/approach: A special crash test device is used in different temperatures and the simulated crash tests are performed at a constant speed of 5.52 m/s.Findings: The specimen is submitted to impact tensile test at different temperatures. According to testing temperature, fracture mode varies: At low temperatures, brittle fracture occurs: due to stress concentration, fracture always occurs in the notched section. At high temperatures, the specimen fails by ductile fracture. Toughness of the steel sheets (base metals, BM or welded parts) is well compared at different materials and test conditions.Research limitations/implications: Evaluation of welded thin sheets submitted to the dynamic loading in order to correlate in real service conditions in order to realize a useful correlation between the transition temperature and deep drawability can be used for evaluating of the welding conditions and also of the material characteristics. For detail study, this type of the test needs a standard formulation.Practical implications: This is a new conception of specimen and of the impact/crash machine. It is widely used in automotive industry for practical and economic reason to give rapid answers to designer and also steel makers for ranking the materials.Originality/value: New developed test called impact crash test for evaluating the toughness of thin welded joints (tailored blanks) / mechanical assemblies in high formability steel sheets for stamping submitted to dynamic loads such as experienced in real crash tests.
MICROSTRUCTURE AND FATIGUE PROPERTIES OF RAIL STEELS
钢轨显微组织与疲劳性能

ZHOU Qingyue,ZHOU Chenguang,
周清跃
,周晨光

金属学报 , 1990,
Abstract: The subcritical propagation of fatigue crack and the microstructure ofthe rail steels with relation to stress ratio have been studied. The effect of micros-tructure of the rail steels on their fatigue lives has been discussed preliminarily.
The role of carbon segregation on nanocrystallisation of pearlitic steels processed by severe plastic deformation  [PDF]
Xavier Sauvage,Yulia Ivanisenko
Physics , 2008, DOI: 10.1007/s10853-006-0750-z
Abstract: The nanostructure and the carbon distribution in a pearlitic steel processed by torsion under high pressure was investigated by three-dimensional atom probe. In the early stage of deformation (shear strain of 62), off-stoichiometry cementite was analysed close to interphase boundaries and a strong segregation of carbon atoms along dislocation cell boundaries was observed in the ferrite. At a shear strain of 300, only few nanoscaled off-stoichiometry cementite particles remain and a nanoscaled equiaxed grain structure with a grain size of about 20 nm was revealed. 3D-AP data clearly point out a strong segregation of carbon atoms along grain boundaries. The influence of this carbon atom segregation on the nanostructure formation is discussed and a scenario accounting for the nanocrystallisation during severe plastic deformation is proposed.
The microstructure and properties of the new bainitic rail steels  [PDF]
J. Pacyna
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The aim of this research was presentation of the Continuous Cooling Transformations (CCT) diagrams and mechanical properties of two new bainite rail steels with working names RB370 and RB390.Design/methodology/approach: The CCT duiagrams was prepared by dilatometric method. The mechanical properities (Rp0,2, Rm, A, Z, KV, KU2, KIc and KIc –20) was searched according to European Standards.Findings: It was found, that on the whole cross – section of rails (S49 or UIC60) made of this new steels only bainite (mainly low bainite) will be formed.Practical implications: Very high mechanical properties of new grades encouraged to implement the first one (nickel – free with hardness of 370 HBW) on commercial scale. Rails (S49) made of it are successfully operating as part of main exit track from ArcelorMittal Steel Plant of Poland in D browa Górnicza since 2004 year.Originality/value: Orginal value of the paper is to give an information, that it is possibility to procedure bainite rails S49 or UIC60 types of a very high mechanical properties, directly in rolling mill.
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