What is the main purpose of the glow

glow

At the Soft annealing of steel become existing precipitations of cementite or perlite are reduced, to the To reduce the hardness and strength of the steel and the To facilitate deformation. Typical temperatures for this are 680 ° C - 780 ° C.

Stress relief annealing takes place at relatively low temperatures between 480 ° C and 680 ° C instead and causes Residual stresses in the workpiece eliminated introduced by mechanical deformation or machining. Otherwise the Steel properties as far as possible not changed become.

The Normalizing of steels one of the most important heat treatment processes. It aims at the formation of one fine-grained structure of crystallites, the evenly distributed over the workpiece are off. For steels with With a higher carbon content, the annealing temperature is just below 800 ° C; for steels with low carbon content the temperature rises for that Normal annealing up to 950 ° C.

At the Coarse grain annealing should the Size of the individual crystallites can be increased. In order to humiliated the Strength and toughness of the materialwhat is desired in certain machining methods.

Under Recrystallization annealing one understands the Restoration of crystallite forms like them in front of one Cold deformation existed to have. For this purpose, the workpiece is usually brought to temperatures just above the recrystallization temperature heated between 550 ° C and 700 ° C. The recrystallization temperature depends on the material and the degree of deformation.

Purpose: Improvement of the workability
Ferrite and spherical carbides (cementite) with even distribution = optimal deformability
Longer time
hold than at Soft annealing (over 8 hours)
Hardening before the GKZ = better distribution of carbon
Glow at about 700 ° C