Modified hybrid damage criterion for the cross wedge rolling process

Abstract

This paper considers the problem of material fracture in the cross wedge rolling (CWR) process. A modification of the hybrid damage criterion dedicated to crack prediction in CWR was proposed. The aim of the modification was to make the limits of the new criterion independent of the implementation temperature of the calibration tests. A rotary compression test was carried out to obtain specimens in which cracking is initiated. Based on the analysis of the FE results of the rotary compression test simulation, the final version of the modified hybrid damage criterion (MHDC) was presented. Using the results of experimental tests and FE simulations, the MHDC limit values were determined. The MHDC limits for the three different temperatures were obtained at similar levels, indicating that the MHDC limits can be made independent of the rotary compression test execution temperature. The MHDC was verified on the example of the cross wedge rolling of a railway axle forging. The verification carried out confirmed the possibility of predicting cracks in CWR-rolled forgings using MHDC. The research results obtained are of an applied nature. In particular, the criterion developed can be helpful in the design of cross wedge rolling technology.