用四点弯曲恒定载荷法结合慢应变速率拉伸试验，研究了由热浓碱液引起的２０Ｇ钢板焊缝区应力腐蚀开裂行为及Ｎｉ－Ｃｒ－Ｆｅ涂层防护效果和耐蚀特性．结果表明，碱脆最严重的区域发生在焊接接头的近缝区，增加恒定载荷，延长腐蚀时间，都使应力腐蚀拉伸强度σｂｓｃ下降；用应力腐蚀临界时间可衡量材料的应力腐蚀敏感性，据此评价了涂层的防护效果． The four-point bending constant load method combined with the slow strain rate tensile test was used to study the stress corrosion cracking behavior of the weld zone and the protective and corrosion-resistant properties of Ni-Cr-Fe coating caused by hot concentrated alkali solution. The results show that the region with the most severe alkali-brittleness occurs in the near-seam area of ​​the welded joint, the constant load and the extended corrosion time decrease the stress corrosion tensile strength σbsc. The stress corrosion susceptibility, Accordingly, the protective effect of the coating was evaluated.