利用热浸铝结合扩散热处理改善孪生诱发塑性(TWIP)钢的耐蚀性  

Improved Corrosion Resistance of TWIP Steel by Using Hot-dip Aluminum Combined with Diffusion Heat-treatment Process

作　　者：汪聃 王文[2] WANG Dan;WANG Wen(School of Physics and Electronic Information,Yan’an University,Yan’an 716000,China;School of Mechanical and Vehicle Engineering,Changzhou Institute of Technology,Changzhou 213032,China)

机构地区：[1]延安大学物理与电子信息学院,陕西延安716000 [2]常州工学院机械与车辆工程学院,江苏常州213032

出　　处：《材料科学与工程学报》2023年第3期391-396,403,共7页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51701206);陕西省自然科学基金资助项目(2019JQ-833);安徽省自然科学基金资助项目(1808085QE166);陕西省教育厅专项科研计划资助项目(19JQ0974);延安大学博士科研启动资助项目(YDBD2018-21)。

摘　　要：利用热浸铝结合扩散热处理在孪生诱发塑性(TWIP)钢表面制备了Fe-Al化合物涂层,并对涂层的组织及浸铝合金的耐蚀性进行了研究。结果表明,初始热浸铝试样过渡层包括棒状的Fe-Al化合物区和少量Fe-Al化合物与Fe-Mn-Al-Si基体共存区。随扩散热处理温度的升高,合金扩散层厚度快速增大,涂层组织逐渐由富铝相向富铁相转变,1050℃时,由Fe_(2)Al_(5)和FeAl_(3)相全部转变为Fe_(3)Al相。电化学试验表明,TWIP钢经热浸铝及1050℃扩散处理后耐蚀性明显增强,腐蚀电位从-0.849V增加到-0.625V,腐蚀电流则从26.1μA/cm^(2)降低到2.70μA/cm^(2)。这主要是由于扩散层中的铝含量较高,在NaCl溶液浸泡时,表面易形成致密的Al2O3钝化膜,能够有效降低初始阶段阴极电流密度,同时Fe3Al化合物涂层也具有更高的耐蚀性能。In this paper,Fe-Al intermetallic layers were formed on the surface of twinning induced plasticity(TWIP)steel by molten aluminum hot-dipping and subsequent heat diffusion treatment.The microstructure of the coating and the corrosion resistance of the immersed aluminum alloy were studied.The results show that,the transition layer of the initial hot-dip aluminum sample contains the rod-shaped Fe-Al intermetallic compound area and a coexistence area comprised by a small amount of Fe-Al compound and Fe-Mn-Al-Si matrix.With the increase of the heat-treatment temperature,the coating structure gradually transforms from the aluminum-rich phase to an iron-rich phase.At 1050℃,it fully changes from Fe_(2)Al_(5) and FeAl_(3) phases to Fe3Al phases.It was found the corrosion resistance of TWIP steel had been significantly improved with the corrosion potential increased from-0.849 V to-0.625 V and the jcorr reduced from 26.1μA/cm^(2) to 2.70μA/cm^(2).This is mainly ascribed to a dense Al_(2)O_(3) passivation film that can be easily formed on the surface of the material in the stable immersion stage due to the higher aluminum content of the diffusion layer,which effectively reduces the cathode current density in the initial stage.At the same time,the surface coating composed of Fe3Al compound also has higher corrosion resistance.

关 键 词：孪生诱发塑性钢 热浸铝 耐蚀性 FE-AL金属间化合物 极化曲线 

分 类 号：TG142[一般工业技术—材料科学与工程]