A, incomplete annealing and completely annealing

(1) incomplete annealing and incomplete annealing. The steel is Ac1 way with heat Ac1 or with Acm Ac3 between a temperature, slow cooling down after the heat preservation, make steel organization does not completely heavy crystallization.

(2) incomplete annealing is heated to half piece of austenite annealing, and fully annealing on workpiece is heated to be completely austenitic optimization for annealing.

(3) incomplete annealing is commonly used to GuoGongXiGang, usable also YaGongXiGang, and fully used only for YaGongXiGang general annealing.

(4) completely annealing generally get flake pearlite, but not completely annealing obtain globular pearlite.

Second, incomplete application range of annealing

Incomplete annealing can be used to YaGongXiGang, can also be used to have steel. After annealing characteristics is of pearlite cementite into shape, this is called again after annealing of ball annealing.

For YaGongXiGang is not entirely by the following situations: annealing often

(1) improve machinability, this kind of annealing is mainly applied to the structure, especially after the forging of high carbon structural, because after the forging, hardness higher difficulty of pearlitic meticulous cutting.

(2) to improve the performance of cold deformation, this kind of ball annealing for cold sex YaGongXiGang deformation.

Third, in general annealing of isothermal annealing

With the general annealing of isothermal annealing process and cooling method, there is usually normal anneal heat preservation process after the completion of the workpiece with slow cooling furnace, when the workpiece cooling to 500 degrees Celsius can come air-cooling. But the isothermal annealing heat insulation, workpiece is faster cooling speed cold to Ac1 below a certain temperature for a period of time, make the austenite decomposition for isothermal cooling, then faster pearlitic speed (air-cooling) to room temperature. In short, isothermal annealing of good quality.

Four, isothermal cooling method of annealing

(1) the annealing temperature cold and workpiece cooling speed of isothermal temperature can be used in production, two furnace.

(2) the isothermal temperature are generally in 10-30 degrees below Ar1, also is in pearlite transition temperature.

(3) change after cooling can be arbitrary

Five, the ball back

(1) general ball back: steel with high heat until Ac1 (usually Ac1 + 20-30 degrees Celsius), thermal insulation in 20-50 degrees after a slow cooling/h to 500 degrees centigrade, baked air-cooling.

(2) with the ball back: the isothermal ordinary ball back the same heating temperature preservation, furnace cold to slightly below the isothermal temperature, isothermal Ar1 after come air-cooling.

(3) : it is the ball back out in Ac1 above and below the alternate heating and cooling, isothermal ball back to cold times.