Structure-property relationships in heat-affected zone of gas-shielded arc-welded V-N microalloyed steel  

作　　者：Jun Hu Lin-xiu Du Bin Zhang Xiang-yu Qi Xiu-hua Gao R.D.K.Misra 

机构地区：[1]The State Key Laboratory of Rolling and Automation, Northeastern University,Shenyang 110819,Liaoning,China [2]Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical,Materials and Biomedical Engineering,University of Texas at El Paso,El Paso, TX 79968-0521,USA

出　　处：《Journal of Iron and Steel Research International》2018年第12期1244-1254,共11页

基　　金：the National Natural Science Foundation of China (Grant No.51604072);the Fundamental Research Funds for the Central Universities (Grant No.N170704016);the National High-Tech R&D Program (863 Program)of China (Grant No.2015AA03A501).

摘　　要：The structure-property relationship in heat-affected zone (HAZ)of a low-carbon steel bearing V-N subjected to gasshielded arc welding was explored.The microstructural characteristics of base metal (BM),coarse-grained HAZ (CGHAZ),fine-grained HAZ,and intercritical HAZ were significantly different.The effect of grain-refinement strengthening and transformation hardening on HAZ contributed to equivalent hardness of 260.8-278.5 HV in comparison with BM hardness of 272.0 HV.Moreover,excellent impact toughness at -20 ℃ was obtained because of high resistance to crack propagation by high-misorientation boundaries,leading to impact fracture consisting of dimples.In CGHAZ,free N was partly fixed by V(C,N)precipitates,such that the deterioration effect of N on toughness was considered to be nearly eliminated.In comparison with CGHAZ,weld metal contained higher fraction of acicular ferrite with fine plates,while the impact toughness was inferior because of the detrimental influence of coarse inclusions from the welding wire.The nanoscale V(C,N)precipitates in CGHAZ had weak effect on toughness because of small size.

关 键 词：V-N MICROALLOYING Heat-affected zone Acicular ferrite Hardness Toughness Gas-shielded arc welding V-N microalloyed STEEL 

分 类 号：TF[冶金工程]