X90管线钢及焊缝在空气和近中性 NS4溶液中的应力腐蚀开裂行为

摘要

Stress corrosion cracking (SCC)behavior of weld and base metal of X90 pipeline in air and near-neutral NS4 solution was investigated by using slow strain rate test.The results indicate that the base metal and weld were sensitive to SCC to a certain degree in near-neutral NS4 solution.The sensitivity of weld was higher than that of base metal and there was mainly plastic loss.The tensile fracture of base metal and weld in air exhibited typical dimple-microvoid ductile fracture, and the tensile fracture in NS4 solution exhibited mixed fracture characteristics.%采用慢应变速率拉伸试验研究了 X90管线钢(母材)及焊缝在空气和近中性 NS4溶液中的应力腐蚀开裂(SCC)行为。结果表明：试验钢母材和焊缝在近中性 NS4溶液中具有一定的SCC 敏感性，且焊缝的敏感性高于母材的，主要表现为塑性损失；母材及焊缝在空气中的拉伸断口表现为典型的韧窝微孔型韧性断裂，在 NS4溶液中表现为混合断裂特征。