Introduction of common heat treatment

Here are some common heat treatments:

1. Normalizing: the heat treatment process of pearlitic structure is obtained by heating the steel or steel parts to the critical point and keeping the appropriate temperature above AC3 or ACM for a certain period of time and then cooling in the air.

2. Annealing annealing: hypoeutectoid steel workpiece heated to above AC3 20 to 40 degrees, heat preservation after a period of time, with the slow cooling furnace (or buried in the sand or lime cooling) to 500 degrees Celsius in air cooling heat treatment process

3. Solution heat treatment: heat the alloy to a high temperature single-phase region to maintain a constant temperature, so that the excess phase fully dissolved into the solid solution, and then fast cooling, in order to obtain the supersaturated solid solution heat treatment process

4. Quenching: the heat treatment process in which the austenitization of steel is cooled at an appropriate cooling rate to make the workpiece undergo the transformation of martensite and other unstable structures in the cross-section or within a certain range

5. Tempering: a heat treatment process in which the quenched workpiece is heated to a suitable temperature below the critical point AC1 for a certain period of time and then cooled in a suitable manner to obtain the desired microstructure and properties

6. Aging: the phenomenon that the properties of an alloy change with time when it is placed at or slightly higher than room temperature after solution heat treatment or cold plastic deformation.

7. Solution treatment: make the various phases of the alloy fully dissolved, strengthen the solid solution and improve the toughness and corrosion resistance, eliminate stress and softening, so as to continue processing

8. Aging treatment: heat and heat preservation at the temperature of precipitation of the strengthening phase, so that the precipitation of the strengthening phase can be hardened and enhance the strength

9. Brazing: heat treatment process in which two workpieces are bonded together with a filler

10. Tempering treatment: the heat treatment combining quenching and tempering at high temperature is called tempering treatment. Tempering is widely used in a variety of important structural parts, especially the connecting rods, bolts, gears and shafts that work under alternating loads. After tempering, the microstructure of tempered sostenite is obtained, and its mechanical properties are better than that of normalized sostenite with the same hardness. Its hardness depends on the tempering temperature at high temperature and is related to the tempering stability of the steel and the section size of the workpiece, generally between HB200 and 350.

11. Carbonitriding of steel: carbonitriding is the process of infiltration of carbon and nitrogen into the surface of steel. Traditionally, carbonitriding is widely used in moderate temperature gas carbonitriding and low temperature gas carbonitriding. The main purpose of medium temperature gas carbonitriding is to improve the hardness, wear resistance and fatigue strength of steel. The main purpose of low temperature gas carbonitriding is to improve the wear resistance and bite resistance of steel.