脱轻组分塔顶系统应力腐蚀开裂研究

ON STRESS CORROSION CRACKING OF LIGHT-COMPONENT REMOVAL COLUMN

通过金相观察、扫描电镜、化学成分分析等方法对苯乙烯装置脱轻组分塔顶系统裂纹开裂原因进行分析,判断出奥氏体不锈钢在连多硫酸介质中形成的应力腐蚀开裂是导致失效的原因。选用321、316L和2205三种材料进行应力腐蚀试验和电化学腐蚀试验,结果显示,316L和2205材料均具有较好耐连多硫酸应力腐蚀能力。上述结论可为该系统选材提供依据。

The failure of stress corrosion cracking of light-component removal column was analyzed by means of metallographic,SEM,and chemical composition analysis.It was concluded that the failure was caused by stress corrosion cracking of austenitic stainless steel in polythionic acid environment.The electrochemical and SCC test of selected stainless steel of 321,316L and 2205 were carried out.The results showed that 316L and 2205 steels have good SCC resistance to polythionic acid.The above conclusions can provide a basis for the selection of materials for the system.