铈对1Cr13马氏体不锈钢抗晶间腐蚀性能的影响

Effect of Ce on Intergranular Corrosion Resistance of 1Cr13 Martensitic Stainless Steel

采用双环电化学动电位再活化测量方法,研究了不同热处理条件下铈对1Cr13马氏体不锈钢的抗晶间腐蚀性能的影响。结果表明,当回火温度为550、650和700℃时,含铈试样的晶间腐蚀程度减轻,再活化率(Ir/Ia)减小;偏聚在晶界处的铈能够阻止碳化物的析出以及偏聚长大,使晶界附近的贫铬程度减少,铈提高了1Cr13试样钢的抗晶间腐蚀性能。同时,随着回火温度的升高,加快了铬元素从基体转移至晶界处贫铬区的速度,从而使贫铬区不断被弥合,最终导致1Cr13不锈钢的抗晶间腐蚀性能也不断地提高。

The effect of cerium on the intergranular corrosion resistance of 1 Cr13 martensitic stainless steel under different heat treatment conditions was studied by double ring electrochemical potentiodynamic reactivation method.The results show that,when the tempering temperature is 550℃,650℃and 700℃,the intergranular corrosion degree of cerium containing sample decreases and the reactivation rate(Ir/Ia)decreases.The segregation of cerium at grain boundaries can prevent the precipitation of carbides and the segregation and growth of carbides,thus reducing the degree of chromium-poor near grain boundaries.The intergranular corrosion resistance of 1 Cr13 steel is improved by Ce.At the same time,with the increase of the tempering temperature,the transfer of Cr elements from the matrix to the Cr-poor zone at grain boundaries is accelerated.As a result,the Cr-poor zone is closed and the intergranular corrosion resistance of 1 Cr13 stainless steel is improved.