液化气球罐应力腐蚀开裂试验研究

由于炼制进口高硫原油,在炼油球罐检验中发现越来越多的内表面应力腐蚀裂纹。对球罐应力腐蚀开裂的原因和主要影响因素进行分析。从液化石油气球罐的安全性出发,采用线弹性断裂力学方法,针对16MnR和SPV50Q球罐所用钢材,在分析湿硫化氢环境下应力腐蚀开裂形式的基础上,通过改进的WOL预裂纹试样的应力腐蚀开裂试验,对不同球罐所用钢材、不同硫化氢浓度、不同焊接状态条件下的应力腐蚀开裂进行研究,并对设备所采用的材料、所处的介质浓度、材料的热处理状况等进行分析,并提出了防止对策。该方法也适用于液化石油气球罐应力腐蚀开裂,以预测事故的发生。

Test Research on the Stress Corrosion Cracking of LPG Spherical Tanks

Owing to refining the imported crude oil containing high sulphur in recent years, more and more cracks caused by stress corrosion were found in the interior surface of spherical tanks during investigation of equipment. To solve this problem, this article firstly analyzed the causes for and the main influence factors of stress corrosion cracking of spherical tanks. Then taking 16MnR steel and the steel of which SPVSOQ is made as examples, by adopting linear elastic fracture mechanics, and based on the test on the cracking of improved pre -fatigue M -WOL specimen, a research on the cracking caused by stress corrosion was conducted under the condition of different steel, different concentration of H2S and different welding methods, materials of which spherical tanks are made, concentration of mediums contained in the tanks and heat treatment condition of materials are analyzed. Finally some preventive countermeasures are proposed. This method is also applicable to forecasting the accident of LPG spherical tanks caused by stress corrosion crack.