用慢应变速率（ＳＳＲＴ） 和恒载荷应力腐蚀试验方法研究了ＮｉＰ化学镀层对３０４Ｌ 钢焊接接头在４２ ％ ＭｇＣｌ２ 溶液和５ ％ ＨＣｌ 溶液中的应力腐蚀（ＳＣＣ） 的影响，并对镀层的最佳磷含量进行了研究。在较低的应力下，特别是在镀层不开裂的情况下，镀层能起到抗ＳＣＣ的作用；而当应力较高（σ＞ σｓ） 时或在ＳＳＲＴ下镀层破裂时，则裂纹首先在镀层破裂处产生，从而镀层失去保护作用。 The effects of NiP electroless plating on the stress corrosion cracking (SCC) of 304L steel welded joint in 42% MgCl 2 solution and 5% HCl solution were studied by slow strain rate (SSRT) and constant load stress corrosion test. The best phosphorus content was studied. Under low stress, especially in the case of non-cracked coating, the coating can play a role of anti-SCC; when the stress is high (σ> σs) or when the coating ruptures under SSRT, Rupture, resulting in loss of protective coating.