摘要
通过中试冶炼、轧制、轧后淬火获得了2种组织形态的低碳高铬钢(5Cr钢,铬的质量分数为5%),采用光学显微镜OM、扫描电镜SEM、XRD、干湿交替实验机、电化学测试等方法研究其相对腐蚀速率,并与Q235碳钢进行比较。结果表明:试样在2%(质量分数)NaCl溶液中周期浸润腐蚀72h后,5Cr钢的不同的组织形态对耐氯离子腐蚀性能影响较大。腐蚀速率的大小为:轧材空冷工艺获得B+M+F复相组织的5Cr钢>淬火工艺获得马氏体组织的5Cr钢>Q235碳钢;马氏体使得5Cr钢的自腐蚀电位Ecorr高于复相组织。含铬钢锈层中存在铬的氧化物、羟基氧化物、铁的氧化物的分层现象,其中铬的富集最高值(质量分数)为17%,最低为1%。淬火工艺获得的板条马氏体使得低碳中铬钢自腐蚀电位的正移以及γ- FeOOH与α- FeOOH等腐蚀产物的形成,而轧材腐蚀性能较差的主要原因可能为B+F等复相组织的? 湟约昂醺直旧怼澳娣础毕窒蟮脑倒省?
Abstract
The two types of microstructure of low carbon and high chromium steel (5Cr) were obtained through the test smelting, rolling and quenching after rolling.Corrosion performance of 5 mass%Cr steel and Q235 steel were researched by means of cyclic wetting and drying corrosion test in 2 mass% NaCl solution.Corrosion behavior and corrosion rust layers were analyzed by OM, SEM, EDS, XRD, cyclic wetting and drying corrosion tester and electrochemical testing. The results show that after the specimens were immersed and etched in 2 mass% NaCl solution for 72h, the different microstructures of 5Cr steel have great influence on the resistance to chloride ion corrosion. B+F+M microstructure of 5Cr steel shows lower corrosion rate than Q235 steel, 5Cr steel with martensite microstructure also shows lower corrosion rate than Q235 steel. Corrosion susceptibility of 5Cr steel with martensite structure is weaker than complex organization.The stratification of chromium oxide, oxyhydroxide, and iron oxide exists in the chromium- containing steel rust layer, in which the Cr enrichment maximum value is 17 mass%, and the lowest is 1 mass%.Lath martensite formed by quenching process makes the corrosion potential rise, γ- FeOOH and α- FeOOH form. Bainite+ferrite phase and adverse phenomenon of Cr steel may cause the poor corrosion resistance.
关键词
高铬钢 周期浸润 马氏体 氯离子腐蚀
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Key words
high Cr steels, cyclic immersion, martensite , chloride ion corrosion
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晁月林 ,周玉丽,程四华,孙齐松,柳洋波.
组织对低碳高铬钢腐蚀行为的影响[J]. 钢铁研究学报, 2018, 30(6): 489-497 https://doi.org/10. 13228/j.boyuan.issn1001- 0963. 20170247
CHAO Yue- lin,,ZHOU Yu- li,CHENG Si- hua,SUN Qi- song,LIU Yang- bo.
Effect of microstructure on corrosion behavior of low carbon high chrome steel[J]. Journal of Iron and Steel Research, 2018, 30(6): 489-497 https://doi.org/10. 13228/j.boyuan.issn1001- 0963. 20170247
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