Convective heat transfer and radiative heat transfer are two essential heat transfer modes in the heating process of steel; it is important to understand the role of them during the heating process clearly. The effects of the convective and radiative heat transfer during the heating process of a cast ingot in a tubular furnace have been studied by the designed natural and forced convection experiments and mathematical simulations. The heating time for the center of the ingot to reach the furnace temperature is decreased with the increase in furnace temperature. According to the experimental and simulation results, a model is proposed regarding the role of radiative and convective heat transfer in the heating process. At low temperature, the convective heat transfer plays a dominant role, while at high temperature, the influence of radiative heat transfer is larger. And a critical temperature exists between them. The forced convective heat transfer can enhance the influence of the convective heat transfer. The critical temperature can be shifted to higher temperatures.

对流传热和辐射传热是钢材加热过程中必不可少的两种传热方式；重要的是要清楚地了解它们在加热过程中的作用。通过设计的自然和强制对流实验和数学模拟，研究了管式炉中铸锭加热过程中对流和辐射传热的影响。钢锭中心达到炉温的加热时间随着炉温的升高而缩短。根据实验和模拟结果，提出了一个关于辐射和对流传热在加热过程中的作用的模型。在低温下，对流换热起主导作用，而在高温下，辐射传热的影响更大。并且它们之间存在临界温度。强制对流传热可以增强对流传热的影响。临界温度可以转移到更高的温度。