关于用ASTM G48 E法检测SUP13Cr临界点蚀温度的探讨

Discussion of Pitting Temperature on SUP13Cr Steel Sample Test with Method E of ASTM G48 Standard

依据ASTM G 48E法对SUP13Cr材质的临界点蚀温度进行测定,并对不同温度的点蚀规律进行了研究,对三种CPT检测方法进行了讨论。实验结果表明使用该方法无法测出该材质的临界点蚀温度,通过不同温度的E法实验发现在0~20℃时材料腐蚀以点蚀为主,点蚀坑深度逐渐增大,壁厚方向减薄不明显;30~40℃时点蚀和均匀腐蚀同时存在,由于壁厚减薄量开始增大,点蚀坑深度变浅,点蚀速率急剧增大;温度大于50℃时完全转变为均匀腐蚀,点蚀坑消失,壁厚减薄量达到最大。

According to ASTM G48 standard E method, we tested the critical pitting temperature （CPT）on SUP13Cr stainless steel samples studied the rule of pitting in different temperature, and then discussed the three CPT test methods. The result showed the CPT of SUP13Cr could not be tested. Based on experiment of different temperatures showed that when the temperature in 0-20 ℃, characterized pitting corrosion, depth increased with increasing temperature, thickness reduction was less obvious; when the temperature in 30-40 ℃, characterized pitting corrosion and uniform corrosion, depth decreased with increasing temperature, thickness reduction was obvious and the rate of pitting corrosion increased sharply, when the temperature above 50 ℃, completely transformed to uniform corrosion, pitting corrosion vanished, thickness reduction reached the maximum.