基于扫描电镜的蒸压釜腐蚀失效分析

Corrosion Failure Analysis of Autoclave Based on SEM

本文以一台蒸压釜定期检验过程中发现的腐蚀缺陷为例,对其筒体内壁点状腐蚀凹坑的产生原因进行分析。通过宏观检验确定了腐蚀类型,采用金相组织、扫描电镜、X射线衍射分析以及原材料化学成分分析等,发现造成该台容器点腐蚀的原因是碱腐蚀和氧腐蚀。将该台蒸压釜安全状况等级评定为4级,监控6个月使用,在使用过程中进行壁厚监测,如壁厚腐蚀超过容器腐蚀裕量,须立即停止使用。

Taking the corrosion defects found in the regular inspection process of an autoclave as an example,this paper analyzes the causes of spot-like corrosion pits in the inner wall of the cylinder.The corrosion type was determined by macroscopic inspection,and then metallographic structure,scanning electron microscope,X-ray diffraction analysis and chemical composition analysis of raw materials were used.It was found that alkali corrosion and oxygen corrosion were the causes of point corrosion of the vessel.The safety level of autoclave is rated as Level 4,and the use of autoclave is monitored for 6 months,the wall thickness should be monitored during the use.If the wall thickness corrosion exceeds the container corrosion allowance,the use should be stopped immediately.