Abstract: 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.

Key words: Cr12MoV Continuous-casting Billet, Flat Bar, High-temperature Diffusion, Temperature-controlled Rolling, Carbide

摘要： Cr12MoV冷作模具钢采用“90 t超高功率电弧炉熔炼→LF+VD精炼→弧形连铸→连铸坯一火轧制”短流程制造工艺已成功工业化生产。此工艺生产的Cr12MoV扁钢厚度大于50 mm成品存在碳化物网状级别偏高的问题，对模具加工和使用性能有着不利的影响。为解决这一问题，结合Gleeble热模拟实验与仿真模拟技术，系统研究了加热温度和变形温度对碳化物形貌的影响。结果表明，适当提高加热温度有助于碳化物的溶解，但过高的温度会降低材料的塑性。尽管变形温度对碳化物形貌的影响不显著，但通过增加变形向扁钢内部的渗透，可以有效改善碳化物的分布。在工业生产实践中，采用加热温度1 170 ℃，5 h的高温扩散工艺，并结合前4个道次的控温轧制，碳化物不均匀度评级从4级提升至2级，显著提升了成品扁钢的碳化物质量。

关键词: Cr12MoV连铸坯, 扁钢, 高温扩散, 控温轧制, 碳化物