采用添加质量分数分别为0，4%，8%，12%，16%，20%MnO的SJ612焊剂，配合SAW-ER308焊丝焊接了18-8不锈钢，研究了MnO含量对焊接接头显微组织、拉伸性能和耐腐蚀性能的影响。结果表明：接头焊缝组织均由奥氏体和铁素体组成，铁素体含量随MnO含量的增加先增大后减少；随着MnO含量的增加，接头的抗拉强度和伸长率先快速增大后增大速率减缓，当MnO质量分数超过12%时趋向稳定；耐腐蚀性能则先增强后减弱，当MnO质量分数为12%时，接头的腐蚀速率最小，为1.86×10^-5 g·mm^-2·h^-1，耐腐蚀性能最好。

18-8 stainless steel was welded using SJ612 flux, which was added with MnO of mass fractions of 0, 4%, 8%, 12%, 16%, 20%, respectively, and SAW-ER308 welding wire, and then the effects of MnO content on the microstructure, tensile property and corrosion resistance of the welded joint were studied. The results show that the microstructures in weld seams of all joints consisted of austenite and ferrite phases, and the ferrite content first increased then decreased with the increase of MnO content. With the MnO content increasing, the tensile strength and elongation of the joint first increased rapidly then slowly and tended to be stable when the mass fraction of MnO was over 12%; the corrosion resistance first increased then decreased. When the mass fraction of MnO was 12%, the corrosion rate of the joint reached the smallest value of 1.86×10^-5 g·mm^-2·h^-1, indicating that the corrosion resistance was excellent.