A novel concept of hybrid treatment for steels is presented. The goal is to produce a hard interstitially hardened/stabilized austenite layer, with an expected improved wear and corrosion resistance, in the surface of high‐hardenability steels. The novelty is in the fact that the thermochemical treatment is performed in the steel metastable austenite field, above the martensite start temperature, during the isothermal step of the martempering or austempering hardening treatment. As a proof of concept, CA6NM martensitic stainless steel samples are subjected to the novel hybrid treatment. The whole treatment is plasma assisted and the chosen thermochemical treatment is nitriding. In the presented case, the produced hard layer is constituted of N‐stabilized austenite. During the paraequilibrium thermochemical treatment step, the metastable austenite surface is converted into a hard interstitially hardened/N‐stabilized austenite. Once concluded the whole treatment, as the component is cooled down to the room temperature, surface does not undergo phase transformation, whereas the nonchemically altered substrate bulk undergoes metastable austenite to martensite phase transformation. So, by means of this case study, the feasibility and potentiality of this novel concept of hybrid treatment is proved.

中文翻译：

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高强度钢混合处理的新概念：伴随淬火和超平衡热化学处理以产生组织间硬化/稳定的奥氏体表面

提出了一种用于钢的混合处理的新概念。目的是在高淬透性钢的表面上产生一个硬质的间断硬化/稳定的奥氏体层，并具有改善的耐磨性和耐蚀性。新颖之处在于，在马氏体或奥氏体淬火处理的等温步骤中，在高于马氏体起始温度的钢亚稳奥氏体场中进行热化学处理。作为概念证明，对CA6NM马氏体不锈钢样品进行了新型混合处理。整个处理是在等离子体辅助下进行的，所选的热化学处理是氮化。在本例中，产生的硬质层由N稳定的奥氏体组成。在超平衡热化学处理步骤中，亚稳态奥氏体表面转变为硬的组织间硬化/ N稳定的奥氏体。一旦完成整个处理，由于将组件冷却至室温，表面不会发生相变，而未化学改变的基体会经历亚稳奥氏体到马氏体的相变。因此，通过本案例研究，证明了这种新颖的混合治疗概念的可行性和潜力。