超低温用高锰奥氏体钢熔池凝固行为及特征  

Solidification behavior and characteristics of molten pool of high manganese austenitic steel for cryogenic application

作　　者：何琼[1] 王红鸿[2] 王杨文 张富伟 李晓晨 HE Qiong;WANG Honghong;WANG Yangwen;ZHANGFuwei;LI Xiaochen(State Key Collaborative Innovation Center for Advanced Steels,Wuhan University of Science and Technology,Wuhan,430081,China;The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan,430081,China;China Merchants Jinling Shipyard(Yangzhou)Dingheng Co.,Ltd,Yangzhou,225217,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,武汉430081 [2]武汉科技大学,省部共建耐火材料与冶金国家重点实验室,武汉430081 [3]招商局金陵鼎衡船舶(扬州)有限公司,扬州225217

出　　处：《焊接学报》2023年第9期60-66,I0006,I0007,共9页Transactions of The China Welding Institution

基　　金：湖北省重点研发计划项目(2021BID003)。

摘　　要：采用埋弧焊工艺制备了高锰奥氏体钢焊缝金属,其主要成分为(质量分数):C元素0.30%~0.50%、Mn元素22.00%~25.00%和Cr元素3.50%~5.50%.通过光学显微镜(optical microscope,OM)、电子背散射衍射分析仪(electron back-scattered diffraction,EBSD)、电子探针显微分析(electro-probe microanalyzer,EPMA)对高锰奥氏体钢焊缝金属的合金元素偏析行为、熔池凝固行为及特征进行分析.结果表明,使用同成分体系焊丝所制备的高锰奥氏体钢焊接接头,其熔合区同样存在不均匀混合区和部分熔化区(partially melted zone,PMZ).试验钢由于热轧产生的C,Mn和Cr的合金元素偏析带,引起焊接接头熔合区中部分熔化区熔化,进一步增加了其元素偏析程度.不均匀混合区以胞状晶形态在部分熔化区上联生结晶,其合金元素分布延续了部分熔化区中的分布.熔池以胞状晶形态在部分熔化区突出的固相半岛上联生结晶,初始胞状晶宽度与母材热轧偏析带间距具有内在关联性,是由部分熔化区热轧带中合金元素的偏析及其熔化所形成的凹凸固液界面所导致.The weld metal of high manganese austenitic steel was prepared by submerged arc welding process with the main composition(wt.%)range of 0.30-0.50 C,22.00-25.00 Mn,3.50-5.50 Cr.The segregation behavior of alloying elements and the solidification characteristics of the molten pool of high manganese austenitic steel were studied by OM,EBSD,EPMA and other analysis methods.The analysis of microstructure and chemical composition shows that there are inhomogeneous mixed zone and partially melted zone(PMZ)in the fusion zone of high manganese austenitic steel welded joints prepared with the same composition system.The alloy element segregation zone of C,Mn and Cr produced by hot rolling in the test steel resulted in partial melting of the PMZ in the fusion zone of the welded joint,and further increases its degree of elemental segregation.The inhomogeneous mixed zone co-crystallizes in the PMZ in the form of cellular crystals,and the distribution of the alloy elements continues the distribution in the PMZ.The molten pool co-crystallizes in the form of cellular crystals on the protruding solid phase peninsula on the PMZ.The width of the initial cytosolic crystals correlates is intrinsically related to the spacing of the hot-rolled segregation bands of the base metal,which is produced by the segregation of alloying elements in the hot rolled strip in the partially melted zone and the concave solid-liquid interface formed by its partial melting.

关 键 词：高锰奥氏体钢 部分熔化区 凝固结晶 偏析 

分 类 号：TG401[金属学及工艺—焊接]