annealing - Stress relieving heat treatment

Annealing is a type of heat treatment that is used to change the structure of the material. There are a number of different types of annealing, depending on the characteristics you want. For example, to minimize internal tension, increase plasticity and, above all - reduce hardness. After machining, surface tension may occur in the metal parts. The surface tension makes the details crack-sensitive. A heating to 550-650 ° C depending on the material will reduce the voltage. Auxiliary annealing is called the type of annealing when the heat removes any tension in the steel that may have arisen in various operations. Then you have a lower heat of 500-600 ° C until you reach the desired result or until the voltage has stopped. Note that cooling after auxiliary annealing should take place slowly.

Normalization is what the type of annealing used to restore the fine-grained structure of the metal is called. A thermal heat treatment method, where metal is cooled in air after heating to minimize stress.
Normalization is performed to make the material more stable. A coarse metal becomes finer. For example, when welding or high temperature throwing, a detail can heat up so much that grain growth has occurred in the steel. Large grains reduce both strength (yield limit) and ductility and are undesirable. Normalization occurs at 30-70 degrees above the conversion line (the temperature at which the material passes to austenite) and then cooled in air.


Soft annealing - also called sputtering annealing. In this case, the steel is heated up to a temperature that is higher than at auxiliary annealing. Here, the structure of the steel is affected and spherical atomic structure is obtained instead of lamellar structure. This treatment produces a smoother but thinner steel, which means that the material does not get as crisp and can handle cold and bite better. Soft annealing is called the annealing which causes the iron carbide of unread steel to be pulled into "bullets", which produces a very soft steel. If the steel has a carbon content of less than 0.9% soft anneals, the material is between 700-723 ° C. If the steel has a carbon content of more than 0.9% soft anneals, the material is between 740-760 ° C. The cooling of the steel after soft annealing will take place very slowly.