Heat treatment
Before the heat treatment | After the heat treatment |
Heat treatment | Solution annealing | To heat the alloy to the high-temperature single-phase region to keep the constant temperature, make the surplus/ excess phase fully melt in the solid solution, and cool it rapidly to get the heat treatment processing of super saturated solid solution. |
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Annealing |
1. Full annealing and isothermal annealing: Full annealing is also called recrystallization annealing, and is briefly called annealing generally. This kind of annealing is chiefly used in the castings, forgings, and hot-rolled sections of various carbon steels and alloy steels of hypo-eutected steel ingredient, and is sometimes used in the welding structure. 2. Spheroidizing: Spheroidizing is mainly used in the hyper-eutected carbon steels and alloy tool steels (such as the steels for manufacturing cutting tools, measuring gauges, and molds). Its major purposes are to reduce the hardness, to improve the machinability, and to make a good preparation for quenching afterward. 3. Stress relief annealing: Stress relief annealing is also called low temperature annealing (or high tempering); this kind of annealing is mainly used to remove the residual stress of the casting, forgings, welding pieces, hot-rolled sections, and cold-drawn steels, etc. If the residual stress is not eliminated, after a fixed period of time, the steels will have distortion or cracks in the process of cutting and processing. |
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Tempering | To heat the workpiece that has gone through quenching to the appropriate temperature under the critical points AC1, keep the temperature for a fixed period of time, and then cool it with the method that conforms to the demand to get the heat treatment processing that we need. | |
Quenching | To make the steel become austenite, and cool it with the appropriate cooling speed, so that the workpiece can have the transformation of unstable organizational structure (such as martensite) inside the transverse sections or within a fixed range to get the heat treatment processing. |