硅含量对一种耐蚀合金组织与耐蚀性能的影响

Effect of Silicon Content on Microstructure and Corrosion Resistance of a Corrosion Resistant Alloy

设计并熔炼了不同硅含量的三种耐磨耐蚀合金30Ni-35Cr-6.5Mo-1Nb-0.25N-xSi(x=1、2、3)-Fe,分别命名为1Si、2Si、3Si合金,利用SEM、XRD、硬度测试以及电化学测试研究了三种合金的组织和性能。结果表明,三种合金均为双相结构,两相分别为γ相和σ-Cr_(13)Ni_(5)Si_(2)相,且随着硅含量的增加,σ-Cr_(13)Ni_(5)Si_(2)相所占的比例逐渐增加,合金的洛氏硬度也逐渐增大。动电位极化曲线以及电化学阻抗谱结果表明,3Si合金在10%H_(2)SO_(4)溶液中的耐蚀效果最优,而1Si合金的耐蚀性最差。合金硬度和耐蚀能力的提高主要得益于合金中σ相比例的增大。

Three Si-containing wear-resistant and corrosion-resistant alloys 30Ni-35Cr-6.5Mo-1Nb-0.25N-xSi(x=1,2,3)-Fe,named 1Si,2Si,3Si,were designed and melted.SEM,XRD,hardness test and electrochemical test were conducted to study the microstructure and properties of the three alloys.The results show that the three alloys have a dual-phase structure ofγ-phase andσ-Cr_(13)Ni_(5)Si_(2),and the proportion ofσ-Cr_(13)Ni_(5)Si_(2) phase gradually increases with increasing silicon content;the Rockwell hardness HRC of the alloys also gradually increases.Potential polarization curves and electrochemical impedance spectroscopy results show that the 3Si alloy has the best corrosion resistance in 10%H_(2)SO_(4) solution,while the 1Si alloy has the worst corrosion resistance.The increase in hardness and corrosion resistance of alloys is mainly due to the increase inσphase ratio.