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

Effect of Cooling Time Following Welding on Microstructure of Welding Coarse Grain Heat Affected Zone of X80 High-Strain Pipeline Steel

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1 000 s时, CGHAZ组织主要由铁素体和少量珠光体组成; 当t8/5在300～60 s时, CGHAZ组织以粒状贝氏体为主; 当t8/5为15 s 时, CGHAZ组织主要是板条贝氏体; 当t8/5≤3 s时, CGHAZ组织则以马氏体为主。

Abstract: 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 bainite 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 t8/5was smaller than 3 s.