A new approach to predict microhardness of two-phase in cutting S32760 duplex stainless steel

The uneven distribution of microhardness in the two-phase structure of S32760 duplex stainless steel after cutting is attributed to variations in the crystal structure, which significantly impact the material's performance. This paper presents a new approach to predict the microhardness of two-phase based on the flow stresses in the austenitic and ferrite. The effect of strain, strain rate, and temperature on the flow stress in the shear plane of orthogonal cutting S32760 was analyzed, and the prediction model for microhardness of two-phase considering the two-phase flow stress was established to obtain a mapping relationship between the two-phase flow stress and the two-phase microhardness of S32760. The impact of cutting dosages on shear strain, strain rate, and temperature in the shear plane was investigated. A function relationship between cutting dosages and microhardness of austenite and ferrite in the shear plane was established, two-phase microhardness experiments were conducted, and the model's accuracy was validated with a prediction error of less than 6%. This study provided insights into the impact of strain, strain rate, and temperature in the shear plane on the microhardness of the two-phase, thus contributing to the theoretical foundation of processing techniques in duplex stainless steel.