Process analysis of lathe spring chuck using high-frequency induction annealing machine for heat treatment

The material of the lathe spring chuck is 9SiCr steel. Hardness requirements: head 60-63HRC, neck 50-55HRC, tail 30-35HRC. In order to meet technical requirements, many manufacturers use high-frequency induction annealing machines for heat treatment, with good results.

(1) Process flow

Forging, annealing, machining (partial connection at the opening), quenching and tempering, machining and grinding the opening.

(2) Heat treatment process

1) Annealing. It is carried out using a high-frequency induction annealing machine with a temperature of 790-800°C.

2) Quenching and tempering of head and neck. A high-frequency induction annealing machine is used, the quenching temperature is 860±10℃, followed by an overall tempering heat treatment of 400℃. After inspection, the hardness of the head and neck is 50-55HRC, and the hardness of the tail is 30-35HRC. Since the hardness of the head does not meet the technical requirements, the head is partially quenched.

3) Partial quenching of the chuck. The quenching temperature is 860±10℃, oil quenching. After testing, the hardness of the chuck reaches 60-63HRC. Finally, perform overall tempering.

4) Overall tempering. The spring collet uses a high-frequency induction annealing machine for overall tempering heat treatment to make it meet the final technical requirements. The spring chuck can expand naturally after being ground open, eliminating the need for the expansion and shaping process. This method has been used in production for many years and has stable quality.

Many manufacturers use the above process for heat treatment, and the hardness of the produced lathe spring chucks is greatly improved, which meets the technical requirements. What's even better is that this process is suitable for large-scale production and can greatly improve workers' production efficiency.