摘要
采用自动钨极氩弧焊接(GTAW)工艺设计刚性约束坡口,制备了304不锈钢1次焊接和1~5次试样。采用光学显微镜、X射线衍射(XRD)、扫描电子显微镜(SEM)与电子背散射衍射(EBSD)技术对重复焊接试样的热影响区(HAZ)显微组织进行观察分析,并开展室温拉伸性能测试,研究重复焊接对显微组织与力学性能的影响。结果表明,重复焊接试样的HAZ显微组织主要由奥氏体和条状δ铁素体组成,随着重复焊接次数增加,HAZ奥氏体晶粒尺寸呈长大趋势,δ铁素体含量先减少后增加,组织择优取向由<101>转变为<111>,局域取向差逐渐增大;晶粒尺寸是影响抗拉强度和延伸率变化的主要原因,加工硬化致使试样屈服强度逐渐增加。
The effect of the repeated welding on the microstructure and mechanical properties of the heat-affected zone(HAZ)for 304 stainless steel were investigated under repeated welding up to five times by automatic gas tungsten arc welding using an optical microscope,a x-ray diffraction,a scanning electron microscope and an electron back-scattered diffraction.The repeated welding specimens were consisted with the microstructures of austenitic matrices with lathδ-ferrite.With the increasing of the repeated welding times,the average values of the austenitic grain size increased,and theδ-ferrite content decreased then increased.The preferred orientation of the HAZ changed from<101>to<111>.The values of location misorientation increased monotonically with the increasing number of repeated welding.The variation of the ultimate tensile strength and elongation was affected by the grain size mainly.Due to the hardening rate increasing,the yield tensile strength was increasing.
作者
郭彦辉
邓冬
孙造占
黄炳臣
Guo Yanhui;Deng Dong;Sun Zaozhan;Huang Bingchen(Nuclear and Radiation Safety Center,Ministry of Ecology and Environment,Beijing,102401,China)
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2021年第4期198-202,共5页
Nuclear Power Engineering
基金
国家重点研发计划(2019YFB1900900)。
关键词
奥氏体不锈钢
重复焊接
热影响区(HAZ)
显微组织
拉伸性能
Austenitic stainless steel
Repeated welding
Heat-affected zone(HAZ)
Microstructure
Tensile properties
