X80管线钢焊接接头拉伸断裂行为与断口形貌分析  

Tensile Fracture Behaviors and Fracture Morphologies of X80 Pipeline Steel Welded Joint

作　　者：孔德军[1,2] 叶存冬[1] 郭卫[1] 

机构地区：[1]常州大学机械工程学院,江苏常州213164 [2]常州大学江苏省材料表面科学与技术重点实验室,江苏常州213164

出　　处：《建筑材料学报》2015年第1期139-144,共6页Journal of Building Materials

基　　金：江苏省科协首席专家(工程师)项目(2013-216);江苏省普通高校研究生科研创新计划项目(CXLX14-1098)

摘　　要：通过拉伸试验分析了X80管线钢母材及其焊接接头拉伸性能,采用扫描电镜及其能谱分析仪观察了上述材料的断口形貌与化学成分,并对其断裂行为进行了研究.结果表明:母材延伸率和断面收缩率大于焊接接头,母材为韧性断口,而焊接接头为出现分层现象的韧断+脆断断口;母材纤维区面积及韧窝尺寸均大于焊接接头,母材放射区形貌为韧窝结构,而焊接接头为解理形貌,母材与焊接接头的剪切唇区均为解理形貌;焊接接头中夹杂物以硫化物和氧化物为主,是焊接接头力学性能降低的重要因素.The tensile mechanical properties of X80 pipeline steel base metal and its welded joint specimens were analyzed by tensile test,the fracture morphologies and chemical compositions were observed with SEM（scanning electron microscopy）and EDS（energy dispersive spectrometer）,and the fracture behaviors were investigated.The results show that elongation and section shrinkage of the base metal are greater than that of the welded joints;the tensile fracture of base metal is tough fracture,while the fracture of welded joint that produces stratification phenomenon is tough＋brittle.The fiber area and dimple size that exist on fiber area in the base metal are greater than that in the welded joint,the morphology of radiation area is dimple,while the cleavage fracture appears in the welded joint,and the shear lip of base metal and welded joint are cleavage.Impurities that is contained in the welding joint are sulfide and oxide,which are an important factor to reduce mechanical properties of welded joint.

关 键 词：X80管线钢 焊接接头 拉伸试验 断口形貌 

分 类 号：U175.3[交通运输工程] TG407[金属学及工艺—焊接]