时效态GH925/625合金焊接力学性能及应力腐蚀研究  

Research on welding mechanical properties and resistance ofstress corrosion crack for the aged GH925 and the Filler 625 Alloy

作　　者：张玉碧 杨晓亮 许倩影 吴洋 黄全振 熊超健 ZHANG Yubi;YANG Xiaoliang;XU Qianying;WU Yang;HUANG Quanzhen;XIONG Chaojian(School of Electrical and Information Engineering,Henan University of Engineering,Zhengzhou 451191,China;Chongqing Materials Research Institute Co.,Ltd.,Chongqing 400707,China)

机构地区：[1]河南工程学院电气信息工程学院,郑州451191 [2]重庆材料研究院有限公司,重庆400707

出　　处：《功能材料》2025年第4期4096-4102,4127,共8页Journal of Functional Materials

基　　金：河南省自然科学基金项目(232300420101);中原科技创新领军人才支持计划(234200510027);国机集团科学技术研究院有限公司青年科研基金项目(SINOMAST-QNJJ-2023-01);河南省大学生创新创业训练计划项目(202311517014)。

摘　　要：时效态GH925合金作为高含硫油井下工件用材,具有优良的力学和耐腐蚀性能,但其焊接性能鲜有报道。采用氩气保护焊(MIG)和625合金焊丝,研究了焊接电流、道次间隔时间(T=1~2 s)对焊接接头组织、晶粒特征、析出相及力学性能的影响。结果表明,在焊接电流50~70 A范围内,获得焊接组织良好,焊接熔合区主要由奥氏体γ相和弥散析出类δ相化合物组成,熔焊区中央以平面结晶为主,两侧为柱状晶组织。焊接参数为50 A+T时,接头强度达到最优530MPa,为焊丝原始屈服强度的1.82倍,道次间隔时间T有利于获得力学性能更好的焊缝组织。采用四点弯梁法,在15%NaCl+1g/L单质硫(S)溶液、H_(2)S分压1.38MPa、CO_(2)分压0.69MPa、149℃条件下浸泡14 d,焊接试样受拉表面光洁,无裂纹和开裂等应力腐蚀现象;腐蚀产物能谱分析主要为(FeCrNi)金属间复杂化合物、NiS以及少量的FeS_(2),Cr_(2)O_(3)和NiO等氧硫化物。As a material for sour oil downhole tools,the aged GH925 alloy has excellent mechanical properties and corrosion resistance,but there are few reports on its welding properties.This experiment used argon gas shielded welding(MIG)and Filler 625 alloy welding wire to investigate the effects of welding current(I)and pass interval time(T=1-2 s)on the microstructure,grain characteristics,precipitation phases,and mechanical properties of the welded joints.The results showed that under the welding current of 50-70 A,uniform welding structure was obtained,and the welding fusion zone was mainly composed of austeniteγphase and dispersed typeδphase complex compounds.The edge of the fusion zone was columnar grains,and the middle region was dominated by planar grains.The yield strength of the welding joint reached the maximum of 530 MPa,which was 1.82 times of the yield strength of Filler 625 alloy,when the welding current was 50 A+T.The pass interval time T was beneficial for obtaining a weld microstructure with better mechanical properties.Using the four points bending beam method,the welding workpieces were immersed for 14 days in 15 wt%NaCl+1 g/L elemental sulfur(S)solution with P H_(2)S of 1.38 MPa,P CO_(2)of 0.69 MPa at 149℃,the sample tensile surfaces were smooth without stress corrosion cracks or failures.Energy spectrum analysis showed that the corrosion products were mainly complex intermetallic compounds(FeCrNi)and NiS,as well as a small amount of oxides and sulfides such as FeS_(2),Cr_(2)O_(3),and NiO.

关 键 词：时效态GH925合金 焊接电流 力学性能 应力腐蚀 

分 类 号：TG142.1[一般工业技术—材料科学与工程]