通过分析线棒材轧后冷却的各个环节,设计并研制了一套在不同冷却工况条件下测量工件和冷却介质间的综合换热系数的新型实验装置。以此为平台,利用综合换热系数反求原理,给出了42CrMo大棒材在自然空冷、强制风冷和水雾冷却条件下的对流换热系数曲线。将所测数据作为边界条件,成功实现了对某厂准150 mm大棒材轧后冷却过程温度场和相变组织演变的有限元准确数值预报。研究结果能为线棒材轧后控冷工艺设计与优化提供重要指导。 By analyzing the various aspects of the cooling after wire bar rolling, a new experimental device for measuring the overall heat transfer coefficient between workpiece and cooling medium under different cooling conditions was designed and developed. Taking this as a platform, the convective heat transfer coefficient curve of 42CrMo large bar under the conditions of natural air cooling, forced air cooling and water mist cooling is given by using the inverse heat transfer coefficient theory. Using the measured data as the boundary condition, the finite element accurate numerical prediction of the temperature field and the phase transformation microstructure of the cooling process of a mill 150 mm big bar has been successfully achieved. The research results can provide important guidance for the design and optimization of the controlled cooling process after wire bar rolling.