摘要
用恒变形U形弯曲试样应力腐蚀试验研究了长期服役在650～720℃下的316L奥氏体不锈钢室温下在0.38mol/L连多硫酸溶液及0.38mol/L连多硫酸+0.5mg/LNaCl溶液中的应力腐蚀破裂(SCC)行为。采用金相显微镜(OM)、扫描电子显微镜(SEM)对裂纹形态、断口形貌进行观察和分析。结果表明,该钢在0.38mol/L连多硫酸溶液中没有发生应力腐蚀破裂现象,而在0.38mol/L连多硫酸+0.5mg/LNaCl溶液中发生了应力腐蚀破裂,裂纹扩展为混合型,氯离子对钢表面钝化膜的破坏是诱发应力腐蚀破裂的主要原因之一。
Stress corrosion cracking (SCC) behaviors of 316L austenitic stainless steel which had served at 650～720℃ for long time were studied by using U-bend samples in 0.38mol/L polythionic acid and 0.38mol/L polythionic +0.5mg/L sodium chloride solution at ambient temperature, respectively. Cracks and fracture morphology were observed and analyzed using optical microscope (OM) and scanning electron microscope (SEM). The results showed that the 316L steel did not exhibit SCC in 0.38mol/l polythionic acid but showed cracking in 0 38mol/L polythionic + 0.5mg/L sodium chloride solution. The crack propagation pathes were both transgranular and intergranular. The destruction of passivation film formed on the surface due to chloride ions should be one of the main causes of stress corrosion crack initiation.
出处
《腐蚀与防护》
CAS
北大核心
2005年第4期147-149,共3页
Corrosion & Protection
关键词
应力腐蚀破裂
奥氏体不锈钢
连多硫酸
Stress corrosion cracking
Austenitic stainless steel
Polythionic acid
