How to deal with the waste heat of forgings

According to the difference of forging waste heat utilization and heat treatment process, forging waste heat treatment commonly used in production mainly includes forging waste heat treatment, forging waste heat treatment and forging waste heat treatment. Let's first understand forging quenching.

Forging hot quenching is the combination of forging and quenching, and immediately enters the quenching medium after hot forging to obtain a quenched structure.

There are many factors affecting the performance of forged and quenched parts such as quenching residence time after forging, quenching medium and its temperature, tempering temperature, deformation, etc.

The forging temperature should adopt low heating temperature (austenitizing temperature) and forging temperature to improve the toughness of forged and quenched parts. Considering comprehensively, the forging heating temperature of general structural steel is about 1200°C, which is more appropriate.

The effect of deformation variables on the properties of forged and quenched parts is not monotonous, because deformation strengthening is accompanied by a destrengthening effect. The deformation enhancement effect is mainly determined by the deformation. As the amount of deformation increases, the strengthening effect is more obvious, but at the same time, the recovery and recrystallization of the strengthening effect are also intensified. The result of the superposition of these two functions makes the forging inevitably have better deformation after quenching.

In order to achieve a good strengthening effect by hot forging and quenching, the deformation of each part of the forging should be considered in the design of the forging die. Try to be as consistent as possible so that the deformations are close. The deformation of forged and quenched parts is generally controlled at 15% to 35%.

The effect of residence time before quenching on properties after forging varies with forged steel and forging process. Carbon steel will complete dynamic recovery and dynamic recrystallization during forging. Staying after forging will not only recrystallize, but also aggregate recrystallization. Therefore, it should be quenched as soon as possible after forging.

For alloy steel, especially when the deformation temperature is low and the deformation is small, it is not easy to recrystallize. Proper stay after forging will form a multilateral structure, which is beneficial to increase the strength, so as to obtain better coordination of strength and toughness, but too long stay time will reduce the strength of the forging. In short, the residence time from forging to quenching should be determined according to specific conditions, and generally should not be long.

Forging hot quenching parts have good quenching performance, and oil is used as the quenching medium for medium carbon steel. In order to avoid excessive temperature difference between the forging and the quenching medium, the temperature of the quenching medium is generally controlled at 60~110°C. The oil outlet temperature of quenched parts is generally 100~150°C.

Forgings and hot quenched parts have high tempering resistance. In order to obtain the same hardness as ordinary quenching and tempering, the high temperature tempering temperature of Hebei forging hot quenching parts is generally about 40 ℃ higher than that after ordinary quenching.