【摘要】 为研究氮对316L不锈钢焊缝力学性能的影响,采用不同氮质量分数的三种自行研制的焊丝,分别对几组316L不锈钢试板进行钨极氩弧焊(Tungsten inert gas,TIG)焊接,焊后通过金相显微镜和扫描电镜分别观察并分析相应的焊缝组织,采用磁性法测量焊缝的铁素体的质量分数,并对焊缝的拉伸性能、冲击性能等力学性能进行测试。从氮的固溶和焊缝组织的变化等方面综合分析氮对316L不锈钢焊缝力学性能的影响。结果发现,随着氮质量分数的增加,焊缝奥氏体组织明显粗化,铁素体质量分数呈下降趋势;焊缝强度有所提高,且氮质量分数由0.011%增加到0.081%时焊缝强度的平均提高程度小于氮质量分数由0.081%增加到0.10%时焊缝强度的平均提高程度;另外,焊缝的塑性及冲击韧度均有所降低。更多还原

【Abstract】 Three kinds of welding wires with different nitrogen content are used for tungsten inert gas(TIG) welding of 316L austenitic stainless steel.Microstructure,ferrite content and mechanical properties of weld metal are analyzed,and the effects of nitrogen solution and microstructure change on the strength of weld metals are investigated.Experiment results show that,with the increase of nitrogen content,the ferrite number(FN) decreases and austenite grains grow remarkably.The strength of the weld metals increases with increasing nitrogen content and it seems that the effect of nitrogen is more remarkable in the range of 0.081% to 0.10%.Both ductility and impact toughness of the weld metals decrease with increasing nitrogen content.更多还原