焊后冷却时间对X80级抗大变形管线钢焊接粗晶热影响区组织的影响

摘要

利用Gleeble-3500型热力模拟试验机研究了焊后冷却时间（t8／5）对X80级抗大变形管线钢焊接粗晶热影响区（CGHAZ）组织的影响。结果表明：当t8／5大于1000S时，CGHAZ组织主要由铁素体和少量珠光体组成；当t8／5在300-60S时，CGHAZ组织以粒状贝氏体为主；当t8／5为15S时，CGHAZ组织主要是板条贝氏体；当t8／5≤3s时，CGHAZ组织则以马氏体为主。%The effect of cooling time following welding （t8/5）on welding coarse grain heat affected zone （CGHAZ） microstructure of X80 high-strain pipeline steel was studied by Gleeble-3500 thermo-mechanical simulator. The results show that ferrite and a small quantity of pearlite were obtained in CGHAZ microstructure when t8/5 was more than 1 000 s, the CGHAZ microstructure was mainly composed of granular hainite when t8/5 was 300--60 s, the CGHAZ microstructure mainly comprised of lath bainite when t8/5 was 15 s, and martensite appeared in CGHAZ primarily when t8/5 was smaller than 3 s.