从金属学角度来看，热轧与冷轧的界限应该以金属再结晶的温度来区分，即低于再结晶温度的轧制为冷轧；高于再结晶温度的轧制为热轧。而钢的再结晶温度一般在450℃～600℃范围之内。
From the point of view of metallization, the boundary between hot rolling and cold rolling should be distinguished from the temperature of recrystallization of metal, that is, the rolling that is lower than the recrystallization temperature is cold rolling, and the rolling that is higher than the recrystallization temperature is hot rolling. The recrystallization temperature of steel is generally within the range of 450 ~ 600.
所谓低温热轧是指稍高于再结晶温度下的轧制。提高轧制温度可以降低轧件温度的屈服应力，使变形功降低。但是由于变形功可以转化为热量，因此，当轧件温度的热损失主要是热辐射时，热损失量与轧件温度的4 次方成正比。
The so-called low temperature hot rolling is a rolling that is slightly higher than the recrystallization temperature. Increasing rolling temperature can reduce yield stress of workpiece and reduce deformation work. However, the deformation work can be converted into heat, so when the heat loss of the rolling temperature is mainly heat radiation, the amount of heat loss is proportional to the 4 time of the rolling temperature.