【摘要】 采用逐层X射线衍射和扫描电镜研究了316L奥氏体不锈钢经QPQ盐浴复合处理后的显微组织。结果表明,渗层组织由表面约10μm厚的Fe3O4和-ξFe2N混合层组成,最内层为含氮扩展奥氏体(S相),在混合层和S相之间为γ-′Fe4N相。在距离表面约10μm的地方,氧含量较高;随着厚度增加并超过10μm时,氧浓度急剧下降,而N浓度随着厚度的增加在约10μm的厚度处达到峰值,之后急剧下降再稍稍升高。更多还原

【Abstract】 Microstructure of 316L austenitic stainless steel after QPQ complex salt bath heat treatment was investigated layer-by-layer by X-ray diffraction(XRD) and the scanning electronic microscopy(SEM).The results show that the QPQ heat-treated layers are composed of a approximate thickness of 10 μm Fe3O4 and ξ-Fe2N mixture from the surface.The γ′-Fe4N occurs at the interface between Fe3O4 and the interior expanded austenite(S phase).The concentration of oxygen is relatively higher from the surface to the depth of approximate 10 μm,and it decreases sharply with the increasing depth over 10 μm,while the concentration of nitrogen reaches the peak value at the distance of approximate 10 μm,but it shows decreasing afterwards and then a little increase with increase of the depth when the nitrided layer depth is over approximate 10 μm.更多还原