| 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. |
| 关键词: 氮 焊接 组织 凝固模式 |
| DOI： |
| 分类号: |
| 基金项目:国防科工委年度项目 |
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| Effect of nitrogen on solidification mode and microstructure of 316L stainless steel |
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DENG Baozhu1,2, MA Chengyong2, PENG Yun1,2, TIAN Zhiling2, LIAO Pibo1
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1.Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650093, China;2.Institute of structural Materials, Central Iron & Steel Research Institute, Beijing 10081, China
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| Abstract: |
| 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. |
| Key words: nitrogen welding microstructure solidification mode |
