1. Normalizing: the heat treatment process of pearlite like structure is obtained by heating the steel or steel piece to a proper temperature above the critical point AC3 or ACM and keeping it in air for a certain period of time.
2. Annealing: the heat treatment process of heating the hypoeutectoid steel workpiece to 20-40 degrees above AC3 and cooling slowly (or buried in sand or lime) with the furnace to 500 degrees below in air after holding for a period of time.
3. Solution heat treatment: heat the alloy to the high temperature single-phase area and keep the temperature constant, so that the excess phase can be fully dissolved in the solid solution, and then rapidly cool to obtain the heat treatment process of supersaturated solid solution.
4. Aging: after solution heat treatment or cold plastic deformation, when the alloy is placed at or slightly higher than room temperature, its properties change with time.
5. Solution treatment: fully dissolve various phases in the alloy, strengthen the solid solution, improve the toughness and corrosion resistance, eliminate the stress and softening, so as to continue processing and forming.
6. Aging treatment: heat and keep warm at the precipitation temperature of the strengthened phase to make the precipitation of the strengthened phase harden and improve the strength.
7. Quenching: a heat treatment process in which the steel is austenitized and cooled at a proper cooling rate, so that the workpiece can undergo the transformation of unstable structure such as martensite in the whole or a certain range of cross section.
8. Tempering: heat the quenched workpiece to a proper temperature below the critical point AC1 for a certain period of time, and then cool it in a satisfactory way to obtain the required structure and performance of the heat treatment process.
9. Carbonitriding of steel: carbonitriding is a process of infiltration of carbon and nitrogen into the surface of steel at the same time. It is commonly known as cyaniding. At present, it is widely used in medium temperature gas carbonitriding and low temperature gas carbonitriding (gas soft nitriding). 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.
10. Tempering treatment: generally, the heat treatment combining quenching and high temperature tempering is called tempering treatment. Quenching and tempering are widely used in all kinds of important structural parts, especially those connecting rods, bolts, gears and shafts working under alternating load. The mechanical properties of tempered sorbite are better than that of normalized sorbite with the same hardness. Its hardness depends on the high temperature tempering temperature and is related to the tempering stability of the steel and the cross-section size of the workpiece, generally between hb200-350.
11. Brazing: a heat treatment process in which two kinds of workpieces are bonded together with solder.
On 2018-08-08 11:45:46
