How is the Hot Forging Temperature Range for Iron Determined?

The hot forging process is carried out within a certain temperature range. The forging temperature range of steel refers to the temperature range between the starting and the ending forging temperature.

The basic principles of hot forging process to determine the forging temperature range are: to ensure that the steel has a high plasticity, lower deformation resistance to get high quality forgings, while forging temperature range as wide as possible, in order to reduce the heating times and improve forging productivity.

The basic method for determining the forging temperature range is: Based on the equilibrium diagram of steel, with reference to the plasticity, resistance and recrystallization diagrams of steel. By the plasticity, mass and deformation resistance to a comprehensive analysis of the three aspects, thus determining the starting forging temperature and final forging temperature.

In general, the forging temperature range of carbon steel can be directly determined according to the iron-carbon balance chart. The forging temperature range for most alloyed structural steels can be considered with reference to carbon steels with the same carbon content. For low plasticity high-alloy steels and steels that do not undergo phase transition (e.g. austenitic steels, pure ferrous steels), a reasonable range of forging temperature can only be obtained through testing.

Hot forging process to determine the initial forging temperature of steel. First of all, the steel must be free from overheating. Therefore, in terms of carbon steel, the beginning of forging temperature should be lower than the iron - carbon equilibrium map of the beginning of the melting line 150 ~ 250℃. In addition, Factors such as blank organization, forging method and deformation process should also be considered.

Hot forging process in determining the final forging temperature, it is necessary to ensure that the steel has sufficient plasticity before final forging, but also to enable forgings to obtain good srtuctural properties. Therefore, the final forging temperature of steel should be higher than the recrystallization temperature to ensure complete recrystallization after forging, so that forgings get fine grain structure.