2205双相不锈钢TIG焊接头组织及力学性能  

Microstructure and Mechanical Properties of 2205 DSS Metal Inert-gas Welding Joints

作　　者：李国平[1] 王建军[2,3] 吴天海[2] 温艳慧 李花兵[4] 刘春明[2,3] LI Guoping WANG Jianjun WU Tianhai WEN Yanhui LI Huabing LIU Chunming(Shanxi Taigang Stainless Steel Co. Ltd, Taiyuan 030003, China School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China Key Laboratory for Anisotropy and Texture of Materials, Northeastern University, Shenyang 110819, China School of Metallurgy, Northeastern University, Shenyang 110819, China)

机构地区：[1]山西太钢不锈钢股份有限公司,太原030003 [2]东北大学材料科学与工程学院,沈阳110819 [3]东北大学材料各向异性与织构教育部重点实验室,沈阳110819 [4]东北大学冶金学院,沈阳110819

出　　处：《材料研究学报》2016年第12期897-902,共6页Chinese Journal of Materials Research

基　　金：国家科技支撑计划项目2012BAE04B01;中央高校基本科研业务费专项资金资助项目N140206001和L1502045;2011计划钢铁共性技术协同创新资助项目~~

摘　　要：对2205双相不锈钢进行了4组不同热输入条件下的TIG焊接实验,采用光学显微镜、扫描电镜和透射电镜对焊接接头的显微组织进行了观察与分析,并测试了焊接接头的拉伸力学性能和显微硬度。结果表明:在热影响区,随着热输入的增大,不完全再结晶区带状奥氏体宽度逐渐增大,粗晶区铁素体晶粒的粗化程度逐渐加剧、奥氏体体积分数逐渐增多;在焊缝金属中,随着热输入的增大,魏氏奥氏体逐渐减少,而块状奥氏体逐渐增多,魏氏奥氏体在高温下稳定性差,容易被相界处形成的窄条铁素体分割成块状奥氏体。随着热输入的增大,焊接接头的屈服、抗拉强度逐渐降低,断后延伸率逐渐升高。铁素体体积分数较高的热影响区显微硬度最大,焊缝金属的合金元素含量较高,因此其显微硬度高于母材。2205 DSS plates were welded with four different heat inputs using TIG welding. The micro- structures of welding joints were carefully observed by means of OM, SEM, and TEM. The tensile proper- ties and microhardness of welding joints were tested and analyzed in detail. The results show that with the increasing of heat input, the width of strip austenite in incomplete recrystallization zone increases and the grain size of ferrite and the volume fraction of austenite in coarse grain zone increase gradually, while Widmanstatten austenite decreases and blocky austenite increases in weld metal. Widmanstatten austen- ite is unstable at high temperature and divided into blocks with the formation of fine strip ferrite at the phase boundary. The tensile strength and yield strength decrease while the elongation increases with the increasing of heat input. According to the results of microhardness, the maximum of microhardness ap- pears in the HAZ where ferrite volume fraction is the highest. The microhardness in weld metal is higher than that in base metal due to the relatively higher amounts of alloy elements.

关 键 词：金属材料 双相不锈钢 TIG焊 热输入 魏氏奥氏体 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]