氮对316L不锈钢焊缝凝固模式和组织的影响  

Effect of nitrogen on solidification mode and microstructure of 316L stainless steel

作　　者：邓宝柱[1,2] 马成勇[2] 彭云[1,2] 田志凌[2] 廖丕博[1] 

机构地区：[1]昆明理工大学机电工程学院,昆明650093 [2]钢铁研究总院结构材料研究所,北京100081

出　　处：《焊接学报》2010年第5期89-92,共4页Transactions of The China Welding Institution

基　　金：国防科工委年度项目

摘　　要：采用氮含量不同的三种焊丝分别对316L奥氏体不锈钢进行了TIG焊接,通过金相显微镜和扫描电镜对其焊缝微观组织进行了观察,对比分析了焊缝的凝固模式和焊缝组织的析出行为,研究了氮对焊缝凝固模式和组织的影响.结果表明,焊缝氮含量为0.018%时,焊缝的主要凝固模式为初生相为铁素体的FA模式,δ铁素体以蠕虫状或网状分布于枝晶轴上;氮含量增加到0.088%和0.16%时,焊缝的主要凝固模式转变为初生相为奥氏体的AF模式,δ铁素体以颗粒状分布于初生奥氏体枝晶间,其数目明显减少;焊缝奥氏体组织随着氮含量的增加有明显的粗化趋势.Three kinds of welding wires with different ni-trogen contents were used for TIG welding of 316L austenitic stainless steel.The solidification mode of the welds and the pre-cipitation behavior of austenite and ferrite were contrastively ana-lyzed,and the effect of nitrogen on solidification mode and mi-crostructure of the weld metal was investigated.The results show that the weld with nitrogen content of 0.018% solidifies as pri-mary ferrite mode and vermicular or skeletal ferrite remains on the dendritic axis.With the increase of nitrogen content to 0.088% and 0.16%,the weld solidifies as primary austenite mode and ferrite occurs as small particles between primary aus-tenite dendrites;the ferrite number(FN)decreases and the re-markably coarse austenite is also found.

关 键 词：氮 焊接 组织 凝固模式 

分 类 号：TG115.28[金属学及工艺—物理冶金]