稀土Ce对1Cr18Mn8Ni5N不锈钢耐均匀腐蚀性能影响

Effect of Ce on Uniform Corrosion Properties of 1Cr18Mn8Ni5N Stainless Steel

利用电化学的极化曲线及交流阻抗技术研究了不同稀土含量的1Cr18Mn8Ni5N不锈钢在硫酸介质中的腐蚀行为。应用扫描电镜对试样的腐蚀形貌及夹杂物形态进行了观察,利用EDS对夹杂物成分进行了分析。结果表明:钢中加入稀土Ce可改变夹杂物形态,并使其交流阻抗的极化电阻增大,极化曲线的腐蚀电位正移,降低了腐蚀电流密度,抵制了均匀腐蚀,改善了1Cr18Mn8Ni5N不锈钢的耐蚀性。当钢中稀土Ce质量分数为0.022%时,1Cr18Mn8Ni5N不锈钢可获得最好的耐均匀腐蚀性能。

The corrosion of different rare-earth content of 1Cr18Mn8Ni5N stainless steel in sulfuric acid medium was investigated by using electrochemical polarization curves and AC impedance.The corrosion morphology and inclusion morphology were observed by SEM and the composition of inclusions were analyzed by EDS.The results show that the inclusion morphology was changed by adding rare-earth Ce in steel.And its polarization resistance of AC impedance increased,the corrosion potential of polarization curve shifted,the corrosion current density reduced,the uniform corrosion of 1Cr18Mn8Ni5N stainless steel was suppressed and the corrosion resistance was improved.The 1Cr18Mn8Ni5N stainless steel with RE Ce element of 0.022% in mass fraction has the best uniform corrosion resistance.