建筑用SM490结构钢焊接接头组织及力学性能的研究  

Microstructure and Mechanical Properties of Welded Joints of SM490 Structural Steel for Building

作　　者：范优铭[1] 袁雷敏[1] 季荣华[1] FAN Youming;YUAN Leimin;JI Ronghua(Changzhou Vocational Institute of Engineering,Changzhou 213164,China)

机构地区：[1]常州工程职业技术学院,江苏常州213164

出　　处：《热加工工艺》2020年第23期134-136,140,共4页Hot Working Technology

基　　金：2015年度江苏省建设系统科技项目(2015ZD38);2017年度江苏省建设系统科技项目及标准(2017ZD154);2017年度江苏省建设系统科技项目(2017ZD157)。

摘　　要：采用金相试验和仪器化压痕试验对建筑用SM490结构钢焊接接头进行了微观组织及力学性能分析,重点研究了压痕试验中应变速率对母材、热影响区和焊缝力学性能的影响。结果发现:SM490结构钢焊接接头局部微区的微观组织差异明显,与母材相比热影响区的晶粒尺寸明显减小,焊缝组织除铁素体和珠光体外还有魏氏体和针状铁素体。仪器化压痕获取的压入曲线可以有效地反映接头局部微区性能失配的问题,应变速率对母材、焊缝和热影响区的屈服强度有明显的影响,压痕试验的应变速率越大,屈服强度越高。The microstructure and mechanical properties of the welded joints of SM490 structural steel for building were characterized by using optical microscope examination and instrumented indentation test. The influence of strain rate during indentation test on the mechanical properties of base metal, heat affected zone and weld metal was mainly investigated. The results show that there is obvious difference between the microstructure of local zones in the SM490 structural steel welded joint. The grain size of the heat affected zone is relatively smaller than that of the base metal.Except for ferrite and pearlite, Widmanstatten structure and acicular ferrite are found in the weld structure. The indentation curve obtained by instrumental indentation can effectively reflect the mismatch of the local micro-region performance of the joint. The strain rate has a significant effect on the yield strength of the base metal, weld and heat affected zone. The larger the strain rate during the indentation test, the higher the yield strength.

关 键 词：应变速率敏感性 仪器化压痕试验 建筑用结构钢 焊接接头 

分 类 号：TG457.11[金属学及工艺—焊接] TG407