High frequency quenching machine manufacturers briefly describe the annealing process of steel

1. Fully annealed

Process: Heating above Ac3 to 30-50°C → heat preservation → cooling to below 500 degrees with the furnace → air cooling to room temperature.

Purpose: to refine grains, uniform structure, improve plasticity and toughness, eliminate internal stress, and facilitate machining.

2. Isothermal annealing

Process: heating above Ac3 → heat preservation → fast cooling to pearlite transformation temperature → isothermal stay → transformation to P → air cooling;

Purpose: Ibid. But the time is short, easy to control, and the deoxidation and decarburization are small. (Suitable for alloy steel and large carbon steel parts with relatively stable supercooled A).

3. Spheroidizing annealing

Concept: It is the process of spheroidizing cementite in steel.