X60螺旋缝埋弧焊管在湿H_2S环境中的腐蚀行为

Corrosion Behavior of Spiral Welded X60 Pipes in Wet H_2S Environment

采用自行设计的焊管实物管段腐蚀试验方法和装置研究了内胀成形和外控成形两种X6 0螺旋缝埋弧焊管在含H2 S的NACE溶液中的腐蚀行为。结果表明 ,焊管在H2 S介质中的损伤表现为母材表面氢鼓泡及应力腐蚀裂纹 ;随着施加应力的提高及残余应力的增大 ,H2 S腐蚀倾向增大 ;在H2 S介质中和外加应力及残余应力的共同作用下 ,焊管的氢损伤机理既有氢致开裂 ,又有氢致应力腐蚀 ,应力不但促进氢致应力腐蚀 ,同时也促进氢致开裂过程 ;试验结果说明改进焊管焊缝表面质量、降低残余拉应力、控制工作应力是改善和控制焊管H2

The H 2S corrosion behavior of over bending and under bending formed spiral submerged arc welded steel pipes in NACE solution has been investigated by use of the self designed full scale pipe corrosion test unit.Results indicate that the H 2S damage of welded pipes shows blister and stress corrosion cracking(SCC) in pipe surface.The H 2S corrosion trend increases with the increase of applying stress and residual stress.The damage mechanism of the welded pipes in H 2S containing solution under the presence of applying stress and residual stress has not only hydrogen induced cracking(HIC),but also stress corrosion cracking,and the applying stress and residual stress promote not only stress corrosion cracking,but also hydrogen induced cracking.The test results reveal that improving pipe surface quality especially weld surface quality,lowering tensile residual stress and controling operating stress are the key measures for controlling the wet H 2S corrosion of welded steel pipes.