168 Forgings net: what are the annealing processes for forgings?
Forgings of annealing process according to the composition requirements of different annealing purpose, can be divided into full annealing incomplete homogenizing annealing spheroidizing annealing (homogenizing annealing) to stress annealing and isothermal annealing recrystallization annealing scope of application:
a. B improve the thick grain structure, refine the grain, eliminate widmanstatten structure and banded structure;
B. Reduce hardness and improve cutting performance;
C. Eliminate internal stress;
D. It can be used as the final heat treatment for unimportant parts.
(2) Incomplete annealing process
Application scope: subeutectoid steel, carbon structural steel, carbon cable tool steel, low alloy structural steel, low alloy tool steel and hypereutectoid steel forging, hot rolled pieces and so on annealing treatment.
Incomplete annealing purpose: to eliminate the internal stress of forging and rolling, reduce hardness, improve toughness.
(3) Spheroidizing annealing
Scope of application:
A. Preparation heat treatment of hypereutectoid steel such as bearing steel and tool steel;
B. Cold deformed forging annealing treatment of medium and low carbon steels and medium and low carbon alloy steels.
The purpose of spheroidizing annealing
A. For forgings requiring cutting, reduce hardness and improve cutting performance;
B. For cold deformation workpiece without cutting, improve the plasticity of cold deformation workpiece;
C. Spheroidized carbide to prevent overheating after quenching and prepare for burial in the final hot place;
[D] Eliminate internal stress.
(4) Isothermal annealing
Isothermal annealing application: die steel, alloy steel forging, stamping parts.
The advantages of isothermal annealing: can shorten the annealing cycle, reduce the production cost.