t_(8/5)对X100管线钢热影响区粗晶区断裂韧性的影响  

Effect of t_(8/5)on fracture toughness of CGHAZ of X100 pipeline steel

作　　者：朱海山 徐连勇[2] 曹健[3] 贾鲁生 Zhu Haishan;Xu Lianyong;Cao Jian;Jia Lusheng(CNOOC Research Institute Ltd.,Beijing 100028,China;Tianjin University,Tianjin 300350,China;Harbin Institute of Technology,State Key Laboratory of Advanced Welding and Joining,Harbin 150001,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028 [2]天津大学,天津300350 [3]哈尔滨工业大学,先进焊接与连接国家重点实验室,哈尔滨150001

出　　处：《焊接》2021年第3期5-12,61,共9页Welding & Joining

基　　金：国家自然科学基金资助项目(51575382)。

摘　　要：按照BS 7448标准并结合显微分析方法,采用热模拟技术对t_(8/5)条件下X100级管线钢焊接热影响区粗晶区(CGHAZ)的断裂韧性(CTOD)进行了研究。结果表明,CTOD值随着t_(8/5)的增加而增加,显微组织由板条贝氏体向粒状贝氏体转化。当t_(8/5)=40 s时,原奥氏体晶界处出现的粗化链状M-A组元,使得断裂韧性出现下降;当t_(8/5)=50 s时,断裂韧性继续增加,但随着热输入的增大,晶粒有粗化的倾向。According to BS 7448 standard and microscopic analysis method,thermal simulation technique was used to study the fracture toughness(CTOD)of the coarse grain zone in heat affected zone of X100 grade pipeline steel under different t_(8/5).The results showed that CTOD value increased as the t_(8/5)time increased,and microstructure was transformed from lath bainite to granular bainite.The coarse chain M-A component appeared at the grain boundary of the prior austenite at t_(8/5)=40 s,which caused a small decrease in fracture toughness.When t_(8/5)was 50 s,the fracture toughness continued to increase.However,the grains tended to coarsen as t_(8/5)increased.

关 键 词：X100管线钢 热模拟 粗晶区 断裂韧性 

分 类 号：TG405[金属学及工艺—焊接]