液化石油气球罐破裂分析

通过对液化石油气球罐裂纹断口金相分析 ,得到裂纹的宏观和微观特征 .采用 EDX- 90 0 0型能量色散谱仪对腐蚀产物做了全谱成分分析 ,结果表明腐蚀产物中有 Fe S和 Ca S存在 ,因此 ,可以断定液化石油气介质中含有 H2 S.经综合分析 ,认为该液化石油气罐裂缝穿透性爆炸属应力腐蚀开裂 ,是阳极溶解腐蚀开裂和阴极氢脆开裂两种开裂形式共同作用的结果 .最后提出了相应的预防措施 :球罐焊接制造和热处理中 ,应尽可能减少焊区的残余拉应力 ;减少液化石油气介质中 H2 S和水的含量 ;加强球罐的定期探伤检测 ,早期发现裂缝 ,早期修复

Analysis of Cracking Failure of a Liquefied Petroleum Gas (LPG) Spherical Tank

In order to find the cause of cracking failure of the LPG spherical tank of a petroleum company, the components of the corrosion products were analyzed by means of EDX 9000 energy dispersion spectrometer. It was found that there are FeS and CaS in corrosion products. According to the analysis of fractography and corrosion product, it is held that the penetrated crack was caused by stress corrosion. The stress corrosion includes active path corrosion and hydrogen embrittlement cracking. Some preventive measures are proposed, such as decreasing the residual tension stress in weld metal zone, decreasing the contents of H 2S and H 2O in LPG, detecting regularly to find and repair cracks in time.