固溶处理后TP347H钢弯管的显微组织及开裂的原因  

Microstructure of TP347H Steel Bent Pipe and Causes for Its Cracking after Solution Treatment

作　　者：汲高飞 李志鹏[1] 宋贤海 黄浩东 蔡熙楠 王荣彩 JI Gaofei;LI Zhipeng;SONG Xianhai;HUANG Haodong;CAI Xinan;WANG Rongcai(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330000,Jiangxi China)

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330000

出　　处：《热处理》2024年第2期50-54,共5页Heat Treatment

摘　　要：TP347H不锈钢弯管在固溶处理和酸洗内壁后发现管口有裂纹。通过宏观分析、金相检验和能谱分析等研究了弯管口部开裂的原因。根据裂纹的扩展方向可以断定,弯管可能在加工或运输过程中被损伤,在外力作用下而开裂。弯管经过固溶处理后,含Nb脆性相沿晶界析出,使晶界脆化,在残余应力的作用下产生裂纹;析出相脱落导致孔洞产生,在变形应力作用下孔洞连接成蠕变裂纹,并沿晶扩展成宏观裂纹。The TP347H stainless steel bent pipe was found to have cracks at its mouth after solution treating and pickling inner wall.The cause for the bent pipe mouth cracking was investigated via macro-analysis,metallographic examination and energy spectrum analysis.From the direction of crack propagation it was concluded that the bent pipe possibly had damages which emanated from processing or transportation,and thereby cracked under the action of applied force.After being solution treated,the brittle niobium-containing phases precipitated along the grain boundary with the result that the grain boundary became brittler and the crack originated under the action of residual stress.The drop-out of precipitates leaded to the formation of holes and their connection under the action of deformation stress,and,as a result,the creep cracks formed and expanded into macroscopic crack.

关 键 词：TP347H不锈钢 弯管 固溶处理 裂纹 微观组织 

分 类 号：TG306[金属学及工艺—金属压力加工]