时效处理对00Crl3Ni7Co5Mo4W马氏体时效不锈钢组织及耐蚀性的影响

采用动电位极化曲线、均匀腐蚀全浸试验研究了50 kg真空感应炉冶炼的00Cr13Ni7Co5Mo4W马氏体时效不锈钢（/%:0.007C,13.23Cr,7.02 Ni,5.06Co,3.72Mo,0.96W）1100℃1 h固溶,450510℃8 h时效后的耐蚀性能,通过金相显微镜、透射电镜、XRD分析了马氏体时效不锈钢的组织。结果表明,随时效温度升高时效过程析出R相增加,导致钢的耐点腐蚀性下降,同时由马氏体逆转变的奥氏体数量增加,可改善该钢的耐腐蚀性能。00Cr13Ni7Co5Mo4W马氏体时效不锈钢适宜的热处理工艺为1100℃1 h固溶+470℃8 h时效,其年腐蚀速率为1.259 0 μm/a,点蚀击穿电位为252 mV。

Effect of Ageing Treatment on Structure and Corrosion-Resisting Properties of Maraging Stainless Steel 00Crl3Ni7Co5Mo4W

Corrosion-resisting properties of maraging stainless steel 00Crl3Ni7Co5Mo4W (/% : 0. 007C, 13. 23 Cr, 7. 02Ni, 5. 06Co, 3. 72Mo, 0. 96W) melted by 50 kg VIM and solid-solution treated at 1 100 °C for 1 h + aged at 450 ~ 510 fbr 8 h are studied by using potentiodynamic polarization curves and uniform corrosion immersion test, and the structure of maraging stainless steel is observed and analyzed by optical microscope, TEM and X-ray diffraction. Results show that with increasing ageing temperature, the R precipitated phase increases led to decrease of pitting corrosion resistance in steel, while the amount of austenite reversed-transformed into martensite increases it is available to improve the corrosion resisting properties of the steel. The optimum heat treatment process for the maraging stainless steel 00Crl3Ni7Co5Mo4W is solid-solution treating at 1 100℃ for 1 h + ageing at 470℃ for 8 h, its corrosion rate is 1.259 0 μm/a and pitting corrosion potential is 252 mV.