Corrosion Initiation and Propagation on Carburized Martensitic Stainless Steel Surfaces Studied via Advanced Scanning Probe Microscopy
Corrosion Initiation and Propagation on Carburized Martensitic Stainless Steel Surfaces Studied via Advanced Scanning Probe Microscopy
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DOI：
10.3390/ma12060940
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发表时间：
2019-03
期刊：
影响因子：
3.4
通讯作者：
Armen Kvryan;Corey M. Efaw;Kari Higginbotham;Olivia O. Maryon;P. Davis;E. Graugnard;H. Trivedi;M. Hurley
中科院分区：
文献类型：
--
作者：
Armen Kvryan;Corey M. Efaw;Kari Higginbotham;Olivia O. Maryon;P. Davis;E. Graugnard;H. Trivedi;M. Hurley
从历史上看，高碳钢已用于机械应用，因为它们的高表面硬度有助于优异的磨损性能。然而，在腐蚀性环境中，目前的轴承钢表现出不足的耐腐蚀性。马氏体不锈钢由于其高耐腐蚀性和通过渗碳热处理进行表面硬化的能力而对于轴承应用具有吸引力。在此，对UNS S42670进行了三种不同的渗碳热处理：高温回火（HTT）、低温回火（LTT）和碳氮共渗（CN）。磁力显微镜显示了基体和碳化物之间的磁畴差异，而扫描开尔文探针力显微镜（SKPFM）显示了两相之间的90-200 mV伏特电位差。通过SKPFM和原位原子力显微镜（AFM）在纳米尺度上监测腐蚀进程，揭示了热处理之间不同的腐蚀模式，预测电化学测试中的体腐蚀行为。HTT在磨损测试中优于LTT和CN，因此推荐用于非腐蚀性航空航天应用，而CN推荐用于易腐蚀应用，因为它具有出色的耐腐蚀性。这里报道的结果支持使用扫描探针显微镜通过测量碳化物和周围基体之间的纳米级表面性质差异来预测体腐蚀行为。
Historically, high carbon steels have been used in mechanical applications because their high surface hardness contributes to excellent wear performance. However, in aggressive environments, current bearing steels exhibit insufficient corrosion resistance. Martensitic stainless steels are attractive for bearing applications due to their high corrosion resistance and ability to be surface hardened via carburizing heat treatments. Here three different carburizing heat treatments were applied to UNS S42670: a high-temperature temper (HTT), a low-temperature temper (LTT), and carbo-nitriding (CN). Magnetic force microscopy showed differences in magnetic domains between the matrix and carbides, while scanning Kelvin probe force microscopy (SKPFM) revealed a 90–200 mV Volta potential difference between the two phases. Corrosion progression was monitored on the nanoscale via SKPFM and in situ atomic force microscopy (AFM), revealing different corrosion modes among heat treatments that predicted bulk corrosion behavior in electrochemical testing. HTT outperforms LTT and CN in wear testing and thus is recommended for non-corrosive aerospace applications, whereas CN is recommended for corrosion-prone applications as it exhibits exceptional corrosion resistance. The results reported here support the use of scanning probe microscopy for predicting bulk corrosion behavior by measuring nanoscale surface differences in properties between carbides and the surrounding matrix.