摘要
用慢应变速率（ＳＳＲＴ） 和恒载荷应力腐蚀试验方法研究了ＮｉＰ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 Ni P electroless coatings with different P contents were prepared by varying the compositions of electroless plating bath, and the P contents were determined using X ray energy disperse spectrum. The effect of Ni P coating on SCC of 304L steel welding joint in boiling 42% MgCl 2 solution and in 5% HCl solution at 25℃ was investigated by means of slow strain rate tensile test and constant load tensile test. Results showed that a perfect Ni P electroless coating could effectively prevent substrate material from SCC at low stress. Under higher stress(σ>σ s) or in the presence of defects or cracks in the coating, SCC originated from defects or cracks in the base material under the coating. The coating did not provide electrochemical protection to the substrate bacause of the relative relationship of corrosion potentials for the coating and the substrate.
出处
《中国腐蚀与防护学报》
CAS
CSCD
1999年第6期333-338,共6页
Journal of Chinese Society For Corrosion and Protection
关键词
化学镀
应力腐蚀
焊接接头
不锈钢
Ni P electroless coating, 304L steel, Welding joint, SCC
