Control of Carbides and Process Optimization in the Direct Rolling Process of Cr12MoV Flat Steel

The short-process manufacturing technology of Cr12MoV cold work die steel， involving "90-ton ultra-high power electric arc furnace smelting → LF+VD refining → arc continuous casting → one-step hot rolling of continuous casting billet"， has been successfully industrialized production. However， the Cr12MoV flat steel products with a thickness greater than 50 mm produced by this process exhibit a high level of carbide network， which adversely affects the machining and use performance of the molds. To address this issue， this study systematically analyzes the effects of heating temperature and deformation temperature on the morphology of carbides using Gleeble thermal simulation experiments and simulation technology. The results indicate that appropriately increasing the heating temperature facilitates the dissolution of carbides， although excessively high temperatures can reduce the plasticity of the material. While the deformation temperature has an insignificant impact on the carbide morphology， enhancing the penetration of deformation into the interior of the flat steel can effectively improve the distribution of carbides. In industrial production practice， implementing a high-temperature diffusion process at heating temperature 1 170 ℃ for 5 hours， combined with controlled rolling in the first four passes， with the carbide non-uniformity rating improving from level 4 to level 2， significantly improved the carbide quality of the finished flat steel.