摘要
采用光学显微镜、拉伸试验、疲劳试验及扫描电子显微镜对不同脉冲钨极氩弧焊(P-TIG)工艺下小径薄壁0Cr18Ni9 EH油管焊接接头组织、拉伸性能,及最优工艺下EH油管接头的疲劳性能进行了分析。结果表明:不同工艺下管接头焊缝区组织均为δ-铁素体+奥氏体,且热影响区奥氏体晶粒明显粗化。采用基值电流为20 A,峰值电流为50 A,脉冲频率为0.5 Hz,占空比为70%时,小径薄壁管焊接接头拉伸性能最优,该工艺下管接头疲劳极限为106.5 MPa;疲劳断口可分为裂纹源区、稳态扩展区以及瞬断区,随着应力幅值的减小,瞬断区在疲劳断口中所占的比例逐渐减小。
The microstructure,tensile properties of small diameter and thin-walled OCr18Ni9 EH oil pipe welded joints under different pulse TIG welding(P-TIG)processes and fatigue performance of EH tubing joint under the best process were analyzed by using optical microscope(OM),tensile test,fatigue test and scanning electron microscope.The results show that the microstructures of the weld zone of the pipe joints under different processes are all 8-ferrite+austenite,and the austenite grain in the heat-affected zone is obviously coarsened.When the base current is 20 A,the peak current is 50 A,the pulse frequency is 0.5 Hz and the pulse width ratio is 70%,the tensile properties of the small diameter thin-walled pipe joint are the best,and the fatigue strength of the pipe joint is 106.5 MPa.The fatigue fracture contains crack source zone,steady propagation zone and instantaneous fracture zone,as the stress amplitude decreases,the proportion of the instantaneous fatigue zonein thefatigue fracturegraduallydecreases.
作者
张向军
王博玉
祖平文
张祖哲
聂海军
李宁
刘少龙
ZHANG Xiangjun;WANG Boyu;ZU Pingwen;ZHANG Zuzhe;NIE Haijun;LI Ning;LIU Shaolong(Huadian Electric Power Research Institute Co.,Ltd.,Hangzhou 310030,China;School of Materials Science and Engineering,Xi'an University of Technology,Xi'an 710048,China;Huadian Power International Co.,Ltd.Shuozhou Thermal Power Branch,Shuozhou 036000,China;Huadian Shanxi Energy Co.,Ltd.,Taiyuan 030006,China)
出处
《热加工工艺》
北大核心
2023年第11期136-139,143,共5页
Hot Working Technology
