母材成分对X80管道环焊接头冲击性能的影响  

Effect of base metal composition on impact toughness of girth welded joint in X80 pipeline steel

作　　者：陈延清[1,2] 牟淑坤[1] 刘宏[1] 张飞虎[1] 

机构地区：[1]首钢技术研究院,北京100043 [2]北京市能源用钢工程技术研究中心,北京100043

出　　处：《电焊机》2017年第7期10-16,共7页Electric Welding Machine

摘　　要：管线铺设过程中采用自保护药芯焊丝半自动焊焊接工艺,研究母材中Nb含量对X80管线钢环焊接头冲击韧性的影响。试验结果表明:母材的化学成分对焊缝金属的成分有影响,母材中较高的Nb含量经焊接热循环后过渡到焊缝金属中,促进了焊缝金属中M/A组元的形成和含量的增加,沿晶界分布的M/A组元降低了焊缝金属的冲击吸收功,影响了焊缝金属的冲击韧性及稳定性。经过优化焊接工艺参数,控制焊态焊缝金属的组织形貌、M/A含量及其分布,可保障X80自保护药芯焊丝焊缝金属的冲击韧性控制在较高且相对稳定的水平,但工艺窗口较窄。The self-shielded flux-cored wire and semi-automatic welding technology are used in the process of pipe laying to study tile effect of Nb content of base metal on the microstructure and impact toughness of girth welded joint in X80 pipeline steel. The results show that composition of base metal has impact on the composition of weld metal. The higher Nb content of base metal transfers to weld metal after weld thermal cycle,which promotes the formation and content of M/A constituent elements. The M/A effect constituent elements distributing along the grain boundary reduce the impact absorbing energy of weld metal,and affect the impact toughness and stability of weld metal. By optimizing the welding condition,controlling the microstructure and appearance of weld metal as well as the content and distribution of M/A,the impact toughness of X80 self-shielded flux-cored wire weld metal can be maintained a high and relatively stable level,but its procedure window is narrow.

关 键 词：环焊缝 自保护药芯焊丝 冲击韧性 工艺窗口 

分 类 号：TG457.6[金属学及工艺—焊接]