不同钢制造LPG球罐在湿H2S环境下失效行为的对比研究

对16MnR钢和SPV50Q钢液化石油气(LPG)球罐在湿H2S环境下的失效行为进行了对比研究.通过观察从16MnR钢球罐上所取下的严重腐蚀球壳板的裂纹特 征和SPV50Q球罐内壁所作金相复膜照片的裂纹形貌，以及分析现场所测试的硬度和残余应力，表明：16MnR钢球罐的失效是由氢诱导开裂(HIC)所引起，损伤部位发生在母材上，而SPV50Q钢球罐则是由硫化物应力腐蚀开裂(SSCC)所造成，裂纹主要出现在焊接接头附近的热影响区(HAZ).

COMPARISON ON THE FAILURE BEHAVIOUR OF THE LPG SPHERICAL TANK MANUFACTURED FROM DIFFERENT STEELS UNDER THE WET H2S ENVIRONMENT

Comparative studies on the failure behaviour of the liquefied petroleum gas(LPG) spherical tanks,which were manufactured from 16MnR steel and SPV50Q steel respectively and working under the wet H_2S environment,were conducted.By observing the crack feature of the samples cut from the severely corroded shell plates removed from the integral 16MnR spherical tank and the crack morphologies of the metallurgical replica photos made on the internal surface of SPV50Q tank on site,as well as analysing the hardness and welding residual stress measured on site,it was found that the failure of 16MnR tank was attributed to hydrogen-induced cracking(HIC) and the damages occurred on the base metal.While for SPV50Q tank,the failure was attributed to sulfide stress corrosion cracking(SSCC) and cracks mainly appeared in the heat-affected zone(HAZ) around the welded joints.