Deformation Simulation and Failure Analysis of XM‐19 Stainless Steel Bar in Three‐Roll Planetary Rolling

This study establishes a comprehensive framework to investigate subsurface delamination in XM‐19 stainless steel during three‐roll planetary rolling, overcoming the limitation of conventional failure theories, which cannot detect internal cracking. Experimental efforts include metallurgical analysis, high‐temperature tensile testing, and melting point measurements. The zero‐ductility temperature (ZDT) of XM‐19 is 1,290 °C, and its melting range (1,311.1–1,398.8 °C) validates results from thermophysical evaluation. The estimated thermal conductivity is incorporated into finite element simulations to model deformation and thermal evolution during rolling. Benchmark simulations, validated by experiments, reveal a hot core region reaching ZDT ≈9.95 mm below surface, consistent with observed cracks. Circumferential flow velocities of 250–300 mm s −1 at the roll‐bar interface contribute to delamination initiation. A parametric study shows that slower revolution and roll rotational speeds reduce the hot core volume ( V hc ) significantly—with an 85% speed reducing V hc to 0.05% of that in the control case. Conversely, reducing the bar size decreases roll‐bar contact area, intensifies heat accumulation, and may increase delamination risk. These findings provide insights into thermally driven failure mechanisms and offer guidance for optimizing planetary rolling parameters to minimize internal cracking and improve product integrity.