304不锈钢焊缝在NaCl溶液中SCC的下限温度

The Critical Temperature for The SCC of 304SS Weldments in Solutions of NaCl

摘要: 本文用慢应变速率实验技术研究了304不锈钢焊接接头在NaCl溶液中的应力腐蚀行为。结果发现:该体系发生应力腐蚀存在一个界限温度,NaCl浓度低于1.0mol/L时,界限温度随NaCl浓度的增加而下降;NaCl浓度高于1.0mol/L时,SCC的界限温度在很宽NaCl浓度范围内变化不大。并给出了该体系发生SCC的T°(C)-Cl^--SCC图。焊接接头的应力腐蚀发生在焊缝区,应力腐蚀裂纹是沿着奥氏体枝晶间的δ-铁素体扩展的。

Abstract: The stress corrosion cracking of 304SS weldments in NaCl solutions has been shudied by SSRT technique.It was found that there exists a critical temperature for the SCC in this system.The cirtical temperature decreases with the increase of NaCl concentration when the concentration of NaCl is lower than 1.0mol/L, but it doesn't change much in a wide range of NaCl concentration when the concentration of NaCl is higher than 1.0mol/L.The diagram of T(℃)-Cl^--SCC has been given.For the weldment,SCC occurs in weld fusion zone and propagates along δ-ferrite phase between austenite dendrites.