Heat treatment of steel surface

Heat treatment of steel surface

(1) surface quenching:

Is the surface of the steel by rapid heating to above the critical temperature, but the heat cooling quickly, before has not yet had time to spread to the core to the surface layer was quenched martensite structure, and the heart of no phase change, which is to achieve the surface hardened the heart of the same purpose. Suitable for medium carbon steel.

2 chemical heat treatment:

Refers to the chemical elements of the atom, with the aid of atomic diffusion ability at high temperature, put it into the workpiece surface layer, to change the chemical composition and structure of the workpiece surface, so as to make the steel surface layer with a certain requirements of the organization and performance of a heat treatment process. According to the seeping into the elements of the chemical heat treatment of different kinds can be divided into the carburizing, nitriding, cyanide, and four metal seeping method, etc.

Carburizing, carburizing is directed into the steel surface layer of carbon atoms. Is made of low carbon steel workpiece surface layer with high carbon steel, after quenching and low temperature tempering, the workpiece surface layer with high hardness and wear resistance, and the central part of the workpiece is still maintained a low carbon steel toughness and plasticity.

Nitriding: also called nitride, is pointing at the steel surface infiltration process of nitrogen atoms. Its purpose is to improve the surface hardness and wear resistance and increase the fatigue strength, corrosion resistance, etc. At present, a lot of the production of the gas nitriding method.

Cyanide: also called carbonitriding, refers to the steel at the same time entering into the process of carbon and nitrogen atoms. It makes has the character of carburizing and nitriding steel surface.

Metallic cementation: refers to metal atoms into the surface layer of steel process. It is to make the surface alloying of steel, so that the surface has some features of alloy steel, special steel, such as heat resistance, abrasion resistance, oxidation resistance, corrosion resistance, etc. Is commonly used in the production of the aluminized, chromizing, boronizing, siliconizing, etc.

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