超低温高锰钢埋弧焊焊缝金属微观组织及冲击韧性分析  

Microstructure and impact toughness of submerged-arc deposited metal for cryogenic high manganese steel

作　　者：陈亚魁 王红鸿[1] 孟亮 王睿之[2] Chen Yakui;Wang Honghong;Meng Liang;Wang Ruizhi(State Key Collaborative Innovation Center for Advanced Steels, Wuhan University of Science and Technology, Wuhan 430081, China;Research Institute,Baoshan Iron & Steel Co., Ltd , Shanghai 201900, China)

机构地区：[1]武汉科技大学高性能钢铁材料及其应用省部共建协同创新中心,湖北武汉430081 [2]宝山钢铁股份有限公司中央研究院,上海201900

出　　处：《武汉科技大学学报》2020年第5期321-325,共5页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金资助项目(51971165).

摘　　要：采用埋弧焊工艺制备低温高锰钢焊缝金属,其主要成分为:0.20%~0.22%C、20.00%~22.00%Mn及2.80%~3.00%Ni。通过-196℃示波冲击试验,结合微观组织和冲击断口表征,分析了影响焊缝金属低温冲击韧性的微观机理。结果表明,该焊缝金属在-196℃的平均冲击值为68.2 J,断裂类型为延性断裂,断口呈韧窝形貌。焊缝金属能发生延性断裂缘于全奥氏体组织具有优异的塑性变形能力。冲击过程组织发生了马氏体相变,即相变诱导塑性(TRIP)效应,这在一定程度上有益于焊缝金属低温韧性的提升。另外,焊缝金属组织中粒径小于0.5μm夹杂物粒子占比为61.5%,这是其保持良好低温韧性的另一因素。A cryogenic high manganese steel weld metal was prepared by submerged arc welding approach,and the main components were:0.20%~0.22%C,20.00%~22.00%Mn,and 2.80%~3.00%Ni.By using the instrumented impact test at-196℃,combined with microstructure observation and impact fracture characterization,the microscopic mechanism affecting the low-temperature impact toughness of the weld metal was analyzed.The results show that the average impact value of the weld metal at-196℃is 68.2 J,the fracture is ductile and exhibits typical dimple morphology.The ductile fracture of the weld metal is due to the excellent plastic deformation ability of the full austenite structure.The martensitic transformation occurs during the impact process,namely the transformation-induced plasticity(TRIP)effect,which is beneficial to the improvement of the low-temperature toughness of the weld metal to a certain extent.In addition,the inclusions with particle size less than 0.5μm in the microstructure of weld metal accounts for 61.5%,which is another factor for maintaining good low-temperature toughness of the weld mtal.

关 键 词：低温高锰钢 焊缝金属 奥氏体 延性断裂 夹杂物 冲击韧性 

分 类 号：TG142.25[一般工业技术—材料科学与工程] TG423[金属学及工艺—金属材料]