通过光学显微镜、万能试验机以及腐蚀测试系统研究了铬含量(23.87%~25.52%,质量分数,下同)对00Cr25Ni7Mo3N双相不锈钢显微组织、力学性能及耐腐蚀性能的影响。结果表明:随着铬含量的增加,试验钢中铁素体含量增多,奥氏体含量减少,当铬含量为25.5%左右时奥氏体和铁素体两相的体积比接近1∶1;当铬含量由23.87%增加到25.52%后,试验钢的屈服强度和抗拉强度分别提高了57.5,27.5 MPa,冲击功下降了31.7J,但铬含量对试验钢塑性的影响较小;随着铬含量增加,试验钢的点蚀质量损失率明显减小,耐晶间腐蚀性能提高。
The effects of chromium content (23.87wt%-25.52wt%) on microstructure, mechanical properties and corrosion resistance of 00Cr25Ni7Mo3N duplex stainless steel were studied using optical microscopy, universal testing machine and corrosion test system. The results show that with the increase of the chromium content, the ferrite content in the experimental steel increased while the austenite content decreased. The volume ratio of the two phases reached close to 1:1 in the experimental steel with the chromium content around 25.5wt%. When the chromium content increased from 23.87wt% to 25.52wt%, the yield strength and tensile strength were improved by 57.5 MPa and 27.5 MPa respectively and the impact energy decreased by 31.7 J. But the effect of chromium content on the plasticity was little. With the increase of chromium content, the pitting corrosion mass loss of the experimental steel decreased obviously, and the intergranular corrosion resistance was improved.