The annealing process of forgings can be divided into complete annealing, incomplete annealing, spheroidizing annealing, diffusion annealing (homogenizing annealing), isothermal annealing, stress relief annealing and recrystallization annealing according to the composition, requirements and purpose of annealing.

1. Complete annealing process

Application range: annealing treatment of medium carbon steel, medium carbon high alloy steel castings, medium carbon low alloy steel castings, welded parts, forgings, rolled parts, etc.

Effect

1) Improve coarse grain structure, refine grain size, eliminate Widmanstätten structure and banded structure;

2) Reduce hardness and improve cutting performance;

3) Eliminate internal stress;

4) Final heat treatment of non-essential parts.

2. Incomplete annealing process

Application range: annealing treatment of hypoeutectoid steel, carbon structural steel, carbon cable tool steel, low alloy structural steel, low alloy tool steel and hypoeutectoid steel forgings, hot rolled parts, etc.

Effect

Eliminate forging internal stress, reduce hardness and improve toughness.

3. Spheroidizing annealing

Application range

1) Tempering and heat treatment of hypereutectoid steels such as bearing steel and tool steel;

2) Cold deformation forging annealing of medium and low carbon steel and medium and low carbon alloy steel.

Effect

1) For forgings that require cutting, reduce hardness and improve cutting performance;

2) For cold deformed workpieces that do not require cutting, improve plasticity;

3) Form spheroidal carbides to prevent subsequent quenching overheating and prepare for final hot burial;

4) Eliminate internal stress.

4. Isothermal annealing

Application range: die steel, alloy steel forgings, stampings.

Effect

Can shorten annealing cycle and reduce production costs.