316L焊缝与304母材C型环试样应力腐蚀敏感性研究

Research on stress corrosion sensitivity of 316L weld joint and 304 base metal C-ring specimen

采用数值模拟方法对C型环试样进行了应力分析计算,得到了C型环试样沿环向和厚度方向的详细应力分布.通过316L焊缝和304母材在沸腾氯化镁溶液中的应力腐蚀试验,分析了合金元素和应力分布对应力腐蚀性能的影响.结果表明:316L焊缝的抗应力腐蚀性能比304母材好,主要原因是316L不锈钢的含碳量较304低,并且合金元素镍和钼的质量分数较高;通过C型环试样应力腐蚀裂纹的位置和应力分布结果的分析,可以初步确定材料应力腐蚀开裂的临界应力值.

The detailed stress distribution along circumferential and thick direction of C-ring specimen was obtained by numerical simulation method. Through stress corrosion tests of 316L weld and 304 base metal in the boiling magnesium chloride solution, the effects of alloying elements and stress distribution were analyzed. Results show that the stress corrosion resistance of 316L weld joint is superior to 304 base metal, it＇s mainly because that the carbon content of 316L is lower than that of 304, and the Nickel and Molybdenum content of 316L are higher than that of 304; The critical stress value of stress corrosion can be primary determined after a particular analysis about the location of stress corrosion cracks and stress distribution of C-ring specimen.