摘要
某催化剂分子筛装置的奥氏体不锈钢焊缝腐蚀主要集中在交换罐,其材质为1Cr18Ni9Ti或0Cr18Ni9Ti,罐体焊缝腐蚀的部位主要集中在罐底部。在环纵焊缝邻近处液面以下,交换罐在运行期间多处发生微裂纹渗漏现象,渗漏多发生在焊接热影响区,母材中也有发生。本文通过交换罐内腐蚀介质的分析、焊接件的耐蚀性评价、失效分析等实验,分析出腐蚀原因主要是由酸性条件下Cl-引起的晶间腐蚀、应力腐蚀开裂,并从焊缝焊接技术的改进、焊缝的防腐表面处理及新罐的选材等几方面提出相关防腐建议。
A zeolite catalyst unit faced the corrosion of austenitic stainless steel welds which concentrated in the ion-exchange vessel, the material applied are 1Cr18Ni9Ti or 0Cr18Ni9Ti, weld corrosion are mainly concentrated at the bottom of the vessels. At the central and longitudinal weld adjacent below the liquid level of ion-exchangers, multiple micro-cracks leakage were found in the vessels running, leakage occurred mainly in the welding heat- affected zone, and also in the base material. After experiments including the corrosion medium analysis of exchangers, evaluation of corrosion resistance of welded parts and failure analysis, it concluded that corrosion causes were that Cl- under acidic conditions results in inter-granular corrosion and stress corrosion cracking. Welding technology improvement, anti-corrosion surface treatment and material aspects for anticorrosion are recommended in the article.
出处
《中国特种设备安全》
2014年第4期73-77,共5页
China Special Equipment Safety
关键词
焊缝
晶间腐蚀
应力腐蚀
Welding seam Intergranular corrosion Stress corrosion
