When machining metastable austenitic stainless steel with cryogenic cooling, a deformation-induced phase transformation from γ-austenite to α′-martensite can be realized in the workpiece subsurface. This leads to a higher microhardness and thus improved fatigue and wear resistance. A parametric and a non-parametric model were developed in order to investigate the correlation between the thermomechanical load in the workpiece subsurface and the resulting α′-martensite content. It was demonstrated that increasing passive forces and cutting forces promoted the deformation-induced phase transformation, while increasing temperatures had an inhibiting effect. The feed force had no significant influence on the α′-martensite content. With the proposed models it is now possible to estimate the α′-martensite content during cryogenic turning by means of in-situ measurement of process forces and temperatures.

当用低温冷却加工亚稳态奥氏体不锈钢时，可以在工件表面实现从γ-奥氏体到α'-马氏体的形变诱导相变。这导致更高的显微硬度，并因此改善了疲劳和耐磨性。为了研究工件表面下的热机械载荷与所得的α'-马氏体含量之间的相关性，建立了参数模型和非参数模型。结果表明，增加被动力和切削力可促进形变引起的相变，而增加温度则具有抑制作用。进给力对α'马氏体含量没有显着影响。