The generation and microstructural characteristics of the surface layer formed during solution treatment at 1200 °C of a high nitrogen austenitic stainless steel, have been investigated using optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). Contrasting with a bulk microstructure of austenite and ferrite, a multi-layer surface structure is obtained, which consists of a white outer-surface layer which is ferrite and a grey subsurface layer with austenite. Formation of the multi-layer structure occurs through phase transformations between austenite and ferrite due to the various levels of nitrogen diffusion. With increasing solution treatment time, the thicknesses of both the surface and the subsurface layer increase. Hardness tests show that the microhardness increases from the surface layer, to the subsurface layer and then to the bulk. This is attributed to the combined effects of solid solution strengthening from nitrogen and the grain size of austenite or ferrite.

使用光学显微镜，X射线衍射（XRD）和扫描电子显微镜（SEM）结合能量色散X研究了高氮奥氏体不锈钢在1200°C固溶处理过程中形成的表面层的生成和微观结构特征。射线光谱法（EDS）。与奥氏体和铁素体的整体微观结构相反，获得了多层表面结构，其由白色的外表面层（其为铁素体）和灰色的亚表面层组成。由于氮扩散水平的不同，通过奥氏体和铁素体之间的相变发生了多层结构的形成。随着固溶处理时间的增加，表面和地下层的厚度均增加。硬度测试表明，显微硬度从表层到次表层再到块体都增加。这归因于氮固溶强化和奥氏体或铁素体晶粒尺寸的综合作用。