摘要
针对矿井用耐蚀高强钢的开发,介绍了新型耐蚀高强Q690D钢板化学成分、组织及力学性能。主要通过盐雾试验及电化学试验对普通Q690D、耐蚀Q690D钢板的耐蚀性能进行了测试,分析了耐蚀钢的多因素耦合的腐蚀规律,揭示了耐蚀钢的腐蚀机制。结果表明:耐蚀Q690D钢板中较高的Cr元素有利于降低试验钢基体表面的电位差,降低腐蚀倾向;钢板组织状态不同,表面电位差也有一定差异,耐蚀Q690D钢板经淬火+回火处理后得到的回火马氏体/贝氏体组织,强韧良好,耐蚀性较普通Q690D钢板提高1.5倍。EBSD表征结果表明:小角度晶界由于其高度有序结构,具有较小的自由体积和较低的界面能,能够打断大角度晶界的连通性,能够有效地阻断腐蚀沿着大角度晶界的扩展,所以腐蚀速率会随着小角度晶界比例的上升而下降。
In view of the development of corrosion resistant and high strength steel for mines, the chemical composition, structure and mechanical properties of new corrosion resistant and high strength Q690 D steel plate were introduced.The corrosion resistance properties of common Q690 D and corrosion resistant Q690 D steel plates were tested by salt spray test and electrochemical test.Corrosion law of multi-factor coupling of corrosion resistant steel was analyzed and corrosion mechanism of corrosion resistant steel was revealed.The results show that the higher content of Cr in corrosion resistant Q690 D plate is beneficial to reduce the potential difference and corrosion tendency of the base surface of the tested steel.Tempered martensite/bainite structure of corrosion resistant Q690 D plate after quenching and tempering has good strength and toughness, and its corrosion resistance is 1.5 times higher than that of common Q690 D plate.The characterization results of EBSD indicate that small angle grain boundaries, due to their highly ordered structure, small free volume and low interfacial energy, can interrupt the continuity of large angle grain boundaries and effectively block the expansion of corrosion along the large angle grain boundaries, so the corrosion rate will decrease with the increase of the proportion of small angle grain boundaries.
作者
麻衡
何康
邹稳蓬
王竹青
MA Heng;HE Kang;ZOU Wenpeng;WANG Zhuqing(Shandong Iron and Steel Co.,Ltd.,Jinan 271104,China;Penglai Jutal Offshore Engineering Heavy Industries Co.,Ltd.,Yantai 265607,China;Jiangsu Binxin Iron and Steel Group Co.,Ltd.,Lianyungang 222113,China)
出处
《轧钢》
2022年第2期18-23,29,共7页
Steel Rolling
基金
国家重点研发计划项目(2017YFB0304905)。
关键词
耐蚀高强Q690D钢板
耐蚀机理
电化学交流阻抗曲线
小角度晶界
corrosion resistant and high strength Q690D plate
corrosion resistant mechanism
electrochemical impedance curves
small angle grain boundary
