淬火温度对1.25Cr-0.5Mo耐热钢组织和耐腐蚀性能的影响  

Effect of quenching temperature on microstructure and corrosion resistance of 1.25Cr-0.5Mo heat resistant steel

作　　者：郭一二 秦华[1] 梁平[1] 史艳华[1] 金兰 Guo Yier;Qin Hua;Liang Ping;Shi Yanhua;Jin Lan(School of Mechanical Engineering,Liaoning Shihua University,Fushun Liaoning 113001,China)

机构地区：[1]辽宁石油化工大学机械工程学院,辽宁抚顺113001

出　　处：《金属热处理》2019年第2期141-145,共5页Heat Treatment of Metals

基　　金：辽宁省教育厅科学技术研究项目(LS2010098)

摘　　要：采用金相分析、浸泡和电化学方法研究不同淬火温度热处理后的1. 25Cr-0. 5Mo耐热钢的显微组织、耐腐蚀性能。结果表明:淬火温度对1. 25Cr-0. 5Mo耐热钢组织有较大影响,随淬火温度的升高,淬火马氏体板条束尺寸逐渐增大,数量逐渐增多。在3. 5%Na Cl溶液中的腐蚀速率呈先减小后增大的趋势,1. 25Cr-0. 5Mo耐热钢经950℃淬火处理后的腐蚀速率最小,耐蚀性最好。Na Cl溶液温度对1. 25Cr-0. 5Mo耐热钢的腐蚀行为影响较大,20℃时1. 25Cr-0. 5Mo耐热钢表面存在一层完整钝化膜,对基体起到很好的保护作用。随着Na Cl溶液温度升高,钝化膜的完整性遭到破坏,二次钝化区间逐渐消失,1. 25Cr-0. 5Mo耐热钢击破电位、自腐蚀电位减小,维钝电流密增大,耐腐蚀性逐渐减弱。The microstructure and corrosion resistance of 1. 25 Cr-0. 5 Mo heat resistant steel after heat treatment at different quenching temperatures were investigated by means of metallographic analysis,soaking and electrochemical methods. The results show that the quenching temperature has a great influence on the microstructure of the steel. With the increase of quenching temperature,the size and the quantity of martensite laths gradually increases. The corrosion rate in 3. 5% Na Cl solution first decreases and then increases. The corrosion rate of the steel after quenching at 950 ℃ is the lowest,and the corrosion resistance is the best. The temperature of Na Cl solution has a great influence on the corrosion behavior of the steel. At 20 ℃,there is a complete passivation film on the surface of the steel,which plays an important role in protecting the substrate. As the temperature of the Na Cl solution increases,the integrity of the passive film is destroyed,and the secondary passivation zone gradually disappears. The steel has a lower breaking potential,a lower self-corrosion potential,an increased blunt current density,and corrosion resistance gradually weakened.

关 键 词：1.25Cr-0.5Mo耐热钢 淬火温度 显微组织 腐蚀速率 

分 类 号：TG156[金属学及工艺—热处理]