焊后热处理对1.25Cr0.5Mo钢在循环水中腐蚀行为的影响  

Effect of Postweld Heat Treatment on the Corrosion Behavior of 1.25Cr0.5Mo Steel in Circulating Water

作　　者：程傲 史艳华[1] 杨众魁 乔忠立 王玲[1] CHENG Ao;SHI Yan-hua;YANG Zong-kui;QIAO Zhong-li;WANG Ling(School of Mechanical Engineering,Liaoning Petrochemical University,Fushun 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：《材料保护》2021年第6期88-92,共5页Materials Protection

基　　金：辽宁省大学生创新创业训练项目(201810148179)资助。

摘　　要：目前有关焊后热处理对1.25Cr0.5Mo钢的腐蚀行为的影响规律尚无文献报道。为此,对正火态1.25Cr0.5Mo钢分别进行淬火、高温回火及调质,模拟不同的焊后热处理,对其金相组织进行分析,并对其腐蚀行为进行电化学测试,研究了不同热处理对1.25Cr0.5Mo钢组织和耐蚀性能的影响。结果表明:正火态1.25Cr0.5Mo钢的金相组织为铁素体和珠光体,淬火组织为板条马氏体,高温回火组织为粗大铁素体和珠光体,调质态组织为均匀的回火马氏体和细小碳化物;淬火处理加速了1.25Cr0.5Mo钢在工业循环水中的腐蚀速度;高温回火处理对腐蚀行为影响不大;调质处理显著提高了1.25Cr0.5Mo钢的耐蚀性,是因为调质热处理细化了材料的组织,细化后的组织较晶粒粗大的淬火及淬火后高温回火组织更容易形成氧化物膜,阻碍电极的放电过程,从而获得了较好的耐蚀性能。At present,the influence of post-weld heat treatment on the corrosion behavior of 1.25Cr0.5Mo steel has less been reported in literatures.Thus,the normalized 1.25Cr0.5Mo steel was quenched,tempered at high temperature or quenched and tempered to simulate different post weld heat treatment process.Subsequently,the corresponding metallographic structure was analyzed,the corrosion behavior was tested by electrochemical method,and the effect of different heat treatment on the structure and corrosion resistance of 1.25Cr0.5Mo steel was further studied.Results showed that the metallographic structure of normalized 1.25Cr0.5Mo steel was ferrite and pearlite,the quenched structure was lath martensite,the high temperature tempered structure was coarse ferrite and pearlite,and the quenched and tempered structure was uniform tempered martensite and fine carbide.Meanwhile,the quenching treatment accelerated the corrosion rate of 1.25Cr0.5Mo steel in industrial circulating water,but the high temperature tempering treatment had little effect on the corrosion behavior.In contrast,the corrosion resistance of 1.25Cr0.5Mo steel was obviously improved by quenching and tempering.The results show that quenching and tempering heat treatment could refine the structure of the 1.25Cr0.5Mo steel,and the refined structure was easier to form oxide film than the quenching and high temperature tempering structure after quenching,which had coarse grain and hindered the discharge process of the electrode,thus obtaining better corrosion resistance.

关 键 词：1.25Cr0.5Mo钢 焊后热处理 循环水 腐蚀行为 

分 类 号：TG172.4[金属学及工艺—金属表面处理]