Journal of Iron and Steel Research(International)最新文献_第2页

In-situ observation of microstructural evolution in reheated low carbon bainite weld metals with various Ni contents 不同镍含量低碳贝氏体再加热焊缝金属显微组织演变的原位观察

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-12-01 DOI: 10.1016/S1006-706X(18)30019-0

Gao-jun Mao , Rui Cao , Jian-hong Chen , Xi-li Guo , Yong Jiang

{"title":"In-situ observation of microstructural evolution in reheated low carbon bainite weld metals with various Ni contents","authors":"Gao-jun Mao , Rui Cao , Jian-hong Chen , Xi-li Guo , Yong Jiang","doi":"10.1016/S1006-706X(18)30019-0","DOIUrl":"10.1016/S1006-706X(18)30019-0","url":null,"abstract":"<div>Microstructural evolution in weld metals was in-situ observed through utilizing a laser scanning confocal microscope at two cooling rates. The specimens with various nickel contents were adopted for the observation. In the specimen with low fraction of Ni (≤2 wt. %), granular bainite microstructure (i. e. broad surface relief) transformation from intragranular nucleation site was in-situ observed, while, lath bainite microstructure originating from grain boundary of austenite was in-situ observed for specimens with high mass percentage of Ni (≥ 4 wt. %). With increasing nickel content, the transformation temperature dropped. The prior austenite grain size was initially depressed and subsequently coarsened dramatically with the addition of Ni. The microstructure difference was ascribed to various nucleation sites and growth direction in the matrix. On account of those observations, not only the chemical component, cooling rate and microstructure were systematically correlated, but also the microstructural evolution was definite.</div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":"24 12","pages":"Pages 1206-1214"},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(18)30019-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89527333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Effect of solution pH, Cl− concentration and temperature on electrochemical behavior of PH13-8Mo steel in acidic environments 溶液pH、Cl−浓度和温度对酸性环境中PH13-8Mo钢电化学行为的影响

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-12-01 DOI: 10.1016/S1006-706X(18)30023-2

Xue-ying Li , Chun-hua Fan , Qian-lin Wu , Li-hua Dong , Yan-sheng Yin , Chang-jun Wang , Jian-xiong Liang

引用次数: 9

Structural behavior of F− in mould flux melt of CaO-SiO2-Al2 O3-Na2 O-CaF2 system cao - sio2 - al2o3 - na2o3 - caf2体系助熔剂熔体中F−的结构行为

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30167-X

Qiang Gao , Yi Min , Cheng-jun Liu , Mao-fa Jiang

{"title":"Structural behavior of F− in mould flux melt of CaO-SiO2-Al2 O3-Na2 O-CaF2 system","authors":"Qiang Gao , Yi Min , Cheng-jun Liu , Mao-fa Jiang","doi":"10.1016/S1006-706X(17)30167-X","DOIUrl":"10.1016/S1006-706X(17)30167-X","url":null,"abstract":"<div>The influence of fluorine on the structure of CaO-SiO2-Al2O3-Na2O-CaF2 continuous-casting-type slag was measured by Raman spectroscopy, and the degree of polymerization of mould flux and the structural behavior of F− in the melt were investigated by classifying and quantifying the structural species of F− ions. The results exhibit that the main structural units of Si-O tetrahedra are Q0, Q1 and Q2 and the actual measured number of non-bridging oxygen ions in the [SiO4]-tetrahedra (denoted by NBO/T) increases from 2. 73 to 3. 44 with increasing the molar ratio of F to (F+O) (denoted by XF/X(F+O)) from 0. 06 to 0. 19. It means that the degree of polymerization of melt structure decreases with an increase in XF/X(F+O). In addition, most of F− ions were distributed in Si-O tetrahedra and Al-O tetrahedra. With increasing XF/X(F+O), the complex structural units Al-O tetrahedra are gradually replaced by discrete structural units AlF1– because of the breakage of Al-O bonds in Al-O tetrahedra by F− ions, and the Si-O (bridging oxygen) bonds of Si-O tetrahedra are broken to form [SiOnF1–n]-tetrahedra by F− ions coordinating with Si4+.</div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":"24 11","pages":"Pages 1152-1158"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(17)30167-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90092077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Thermo-elasto-visco-plastic finite element analysis on formation and propagation of of-corner subsurface cracks in bloom continuous casting 连铸坯角下裂纹形成与扩展的热弹粘塑性有限元分析

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30168-1

Yu-jun Li, Huan Li, Peng Lan, Hai-yan Tang, Jia-quan Zhang

{"title":"Thermo-elasto-visco-plastic finite element analysis on formation and propagation of of-corner subsurface cracks in bloom continuous casting","authors":"Yu-jun Li, Huan Li, Peng Lan, Hai-yan Tang, Jia-quan Zhang","doi":"10.1016/S1006-706X(17)30168-1","DOIUrl":"10.1016/S1006-706X(17)30168-1","url":null,"abstract":"<div>The formation and propagation of the popular off-corner subsurface cracks in bloom continuous casting were investigated through thermo-mechanical analysis using three coupled thermo-mechanical models. A two-dimensional thermo-elasto-visco-plastic finite element model was developed to predict the mould gap evolution, temperature profiles and deformation behavior of the solidified shell in the mould region. Then, a three-dimensional model was adopted to calculate the shell growth, temperature history and the development of stresses and strains of the shell in the following secondary cooling zones. Finally, another three-dimensional model was used to analyze the stress distributions in the straightening region. The results showed that the off-corner cracks in the shell originated from the mould owing to the tensile strain developed in the crack sensitive regions of the solidification front, and they could be driven deeper by the possible severe surface temperature rebound and the extensive tensile stress in the secondary cooling zone, especially upon the straightening operation of the bloom casting. It is revealed that more homogenous shell temperature and thickness can be obtained through optimization of mould corner radius, casting speed and secondary cooling scheme, which help to decrease stress and strain concentration and therefore prevent the initiation of the cracks.</div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":"24 11","pages":"Pages 1159-1168"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(17)30168-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79551560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Correlation of isothermal bainite transformation and austenite stability in quenching and partitioning steels 淬火配分钢等温贝氏体相变与奥氏体稳定性的关系

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30159-0

Shan Chen, Guang-zhen Wang, Chun Liu, Chen-chong Wang, Xian-ming Zhao, Wei Xu

{"title":"Correlation of isothermal bainite transformation and austenite stability in quenching and partitioning steels","authors":"Shan Chen, Guang-zhen Wang, Chun Liu, Chen-chong Wang, Xian-ming Zhao, Wei Xu","doi":"10.1016/S1006-706X(17)30159-0","DOIUrl":"10.1016/S1006-706X(17)30159-0","url":null,"abstract":"<div>The possible decomposition of metastable austenite during the partitioning process in the high-end quenching and partitioning (Q&P) steels is somewhat neglected by most researchers. The effects of primary martensite and alloying elements including manganese, cobalt and aluminum on the isothermal decomposition of austenite during typical Q&P process were studied by dilatometry. The transformation kinetics was studied systematically and resulting microstructures were discussed in details. The results suggested that the primary martensite decreased the incubation period of isothermal decomposition by accelerating the nucleation process owing to dislocations especially on phase and grain boundaries. This effect can be eliminated by a flash heating which recovered dislocations. Co addition significantly promoted the bainite transformation during partitioning while Al and Mn suppressed the isothermal bainite transformation. The bainite transformation played an important role in carbon distribution during partitioning, and hence the amount and stability of austenite upon final quenching. The bainite transformation during partitioning is an important factor in optimizing the microstructure in Q&P steels.</div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":"24 11","pages":"Pages 1095-1103"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(17)30159-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78126425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Effects of strain states on stability of retained austenite in medium Mn steels 应变状态对中锰钢残余奥氏体稳定性的影响

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30163-2

Mei Xu , Yong-gang Yang , Jia-yong Chen , Di Tang , Hai-tao Jiang , Zhen-li Mi

{"title":"Effects of strain states on stability of retained austenite in medium Mn steels","authors":"Mei Xu , Yong-gang Yang , Jia-yong Chen , Di Tang , Hai-tao Jiang , Zhen-li Mi","doi":"10.1016/S1006-706X(17)30163-2","DOIUrl":"10.1016/S1006-706X(17)30163-2","url":null,"abstract":"<div>Based on uniaxial tensile and plane strain deformation tests, the effects of strain states on the stability of RA (retained austenite) in medium Mn steels, which were subjected to IA (intercritical annealing) and Q&P (quenching and partitioning) processing, were investigated. The volume fractions of RA before and after deformation were measured at different equivalent strains. The transformation behaviors of RA were also investigated. The stability of RA differed across two different transformation stages at the plane strain state: the stability was much lower in the first stage than in the second stage. For the uniaxial tension strain state, the stability of RA corresponded only to a single transformation stage. The main reason was that there were two types of transformations from RA in the medium Mn steel for the plane strain state. One type was that the martensite originated in the strain-induced stacking faults (SISF). The other type was the strain-induced directly twin martensite at a certain equivalent strain. However, for the uniaxial tension state, only the strain-induced twin martensite was observed. Dislocation lines and dislocation tangles were also observed in specimens deformed at different strain states. In addition, complex microstructures of stacking faults and lath-like phases were observed within a grain at the plane strain state.</div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":"24 11","pages":"Pages 1125-1130"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(17)30163-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72668582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Microstructure evolution and mechanical properties influenced by austenitizing temperature in aluminum-alloyed TRIP-aided steel 奥氏体化温度对铝合金trip辅助钢组织演变及力学性能的影响

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30162-0

Ju-hua Liang , Zheng-zhi Zhao , Cai-hua Zhang , Di Tang , Shu-feng Yang , Wei-ning Liu

{"title":"Microstructure evolution and mechanical properties influenced by austenitizing temperature in aluminum-alloyed TRIP-aided steel","authors":"Ju-hua Liang , Zheng-zhi Zhao , Cai-hua Zhang , Di Tang , Shu-feng Yang , Wei-ning Liu","doi":"10.1016/S1006-706X(17)30162-0","DOIUrl":"10.1016/S1006-706X(17)30162-0","url":null,"abstract":"<div>The Fe-0. 21C-2. 2Mn-0. 49Si-1. 77 A1 transformation induced plasticity (TRIP)-aided steel was heat treated at various austenitizing temperatures under both TRIP-aided polygonal ferrite type (TPF) and annealed martensite matrix (TAM) processes. The microstructure evolution and their effects on mechanical properties were systematically investigated through the microstructure observation and dilatometric analysis. The microstructure homogeneity is improved in TPF steel heated at a high temperature due to the reduced banded martensite and the increased bainite. Compared with the mechanical properties of the TPF steels, the yield strength and elongation of the TAM steels are much higher, while the tensile strength is lower than that of TPF steels. The stability of intercritical austenite is affected by the heating temperature, and thus the following phase transformation influences the mechanical properties, such as the bainite transformation and the precipitation of polygonal ferrite. Obvious dynamic bainite transformation occurs at TAM850, TAM900 and TAM950. More proportion of polygonal ferrite is found in the sample heated at 950 °C. The bainite transformation beginning at a higher temperature results in the wider bainitic ferrite laths. The more proportion of polygonal ferrite and wide bainitic ferrite laths commonly contribute to the lower strength and better elongation. The uniform microstructure with lath-like morphology and retained austenite with high average carbon content ensures a good mechanical property in TAM850 with the product of strength and elongation of about 28 GPa · %.</div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":"24 11","pages":"Pages 1115-1124"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(17)30162-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84182414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

A thermodynamic model on predicting density of medium-Mn steels with experimental verification 预测中锰钢密度的热力学模型及实验验证

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30157-7

Guo-hui Shen, Peng-yu Wen, Hai-wen Luo

引用次数: 3

Microstructure and mechanical properties of 20Si2CrNi3MoV steel treated by HDQP process HDQP工艺处理20Si2CrNi3MoV钢的组织与力学性能

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30165-6

Chuan-feng Meng , Lei Zhang , Cun-yu Wang , Yu-jie Zhang , Ying-hui Wei , Yi-de Wang , Wen-quan Cao

引用次数: 1

Mechanical properties of a microalloyed bainitic steel after hot forging and tempering 热锻回火后微合金化贝氏体钢的力学性能

2区材料科学

Journal of Iron and Steel Research(International) Pub Date : 2017-11-01 DOI: 10.1016/S1006-706X(17)30158-9

Zhi-bao Xu , Wei-jun Hui , Zhan-hua Wang , Yong-jian Zhang , Xiao-ii Zhao , Xiu-ming Zhao

{"title":"Mechanical properties of a microalloyed bainitic steel after hot forging and tempering","authors":"Zhi-bao Xu , Wei-jun Hui , Zhan-hua Wang , Yong-jian Zhang , Xiao-ii Zhao , Xiu-ming Zhao","doi":"10.1016/S1006-706X(17)30158-9","DOIUrl":"10.1016/S1006-706X(17)30158-9","url":null,"abstract":"<div>Mechanical properties of a newly developed microalloyed bainitic steel were investigated after the hot forging, air cooling and tempering process. The microstructure of the as-forged bainitic steel mainly consists of granular bainite and ∼20 vol. % martensite. The fraction of retained austenite remains unchanged until tempering at 200 °C, above which it decreases significantly. The increase of tempering temperature leads to decreases of both ultimate tensile strength and total elongation but decreases of both yield strength and reduction of area. The maximum and minimum values of impact toughness were observed after tempering at around 200 and 400 °C, respectively. These effects are mainly attributed to the decomposition of martensite/austenite constituents and the tempering effects in martensite. The tempering of the forged bainitic steel at around 200 °C results in an excellent combination of strength and toughness, which is comparable to that of the conventional quenched-and-tempered 40Cr steel. Therefore, low-tempering treatment coupled with post-forging residual stress relieving is a feasible method to further improve the mechanical properties of the bainitic forging steel.</div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":"24 11","pages":"Pages 1085-1094"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(17)30158-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77752953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9