Carburizing heat treatment can effectively improve the internal structure of metal materials
Carburizing heat treatment can effectively improve the internal structure of metal materials, so that the metal materials have better processing and technology. The material cracking occurred in the production process, the crack is caused by the poor machinability. According to statistics, in mechanical products, due to surface failure caused more than 80% of the parts scrap, and the failure of the parts due to the lack of the overall strength of the material fracture or deformation accounted for a very small proportion. Therefore, to improve the surface wear resistance, corrosion resistance, fatigue resistance and strength of materials is the key to extend the service life of parts, reasonable configuration performance, and ensure the stability of the system.
Well type carburizing furnace
Surface heat treatment technology has been paid great attention to by people, and it plays an increasingly important role in improving the performance of various components of electric furnace such as heating furnace and annealing furnace.
Carburizing depth is generally 0.1~1.5mm, is a medium depth, mainly used for surface hardening. The structure is (Martensite + carbide + residual austenite), and the surface stress state is high residual compressive stress. After quenching, the surface hardness can reach 58~65HRC, and the core hardness is generally about 30HRC. It has good wear resistance, good contact fatigue strength, bending fatigue strength, anti-adhesion and high impact toughness. The deformation tendency of heat treatment is larger, but it is not easy to crack. This process applies to low carbon steel and low carbon alloy steel, such as 15, 20, 12CeNi3, 20Cr2Ni4, 20Cr, 15CrMo, 20CrMo, 20CrMnTi and other ferrous powder metallurgy materials, mainly used for surface wear resistance, fatigue resistance, and the heart of the toughness of heavy load parts. The cost of steel used in this process is low or medium, and the investment of equipment is high.
Vacuum carburizing furnace
The carburizing of 0.1-1.0mm is shallow and is mostly used for surface hardening. The structure is (carbon nitrogen compound + nitrogen containing martensite + residual austenite), and the surface layer is in a state of high residual compressive stress. After quenching, the surface hardness is up to 60~65HRC, high wear resistance, good contact fatigue strength, good bending fatigue strength, good bite resistance and good impact toughness. The deformation tendency and cracking tendency of heat treatment are the same as carburizing and quenching process. This process applies to low carbon steel, low carbon alloy steel, medium carbon alloy steel and iron based powder metallurgy materials, such as medium carbon alloy steel 40Cr, 35CrMo, 42CrMo, etc., low carbon steel, low carbon alloy steel and iron based powder metallurgy materials with carburizing quenching. Mainly used for surface wear resistance, fatigue resistance, and the heart of good toughness in the middle load parts.
0.1-0.4mm carburizing is relatively thin, mainly used for surface hardening. The structure is (nitrogen carbon compound + nitrogen containing solid solution), and the surface layer is in the state of high residual compressive stress. After nitriding, the surface hardness is generally 800~1200HV (63~71HRC), high wear resistance, and at the same time has good contact fatigue strength, good bending fatigue strength, good anti-bite ability and good impact toughness. The deformation tendency and cracking tendency of nitriding treatment are very small. After nitriding parts, generally no longer processing. Under special circumstances, only a small amount of fine grinding can be carried out. The applicable materials of this process are medium carbonized alloy nitrided steel and nodular cast iron, such as 38CrMoAl, 3Cr13, 35CrMo, 42CrMo, 20CrMnTiT, QT600-3, etc. It is mainly used for important parts with high surface wear resistance.
Carbonitriding furnace
Carburized metal compound layer is generally 0.005-0.020mm, mainly used for surface hardening. The hardened layer is composed of (surface carbon nitrogen compound layer + internal nitrogen diffusion layer) and the surface is in a state of high residual compressive stress. After nitrocarburizing, the surface hardness is generally 500~800HV (50~63HRC), high wear resistance, good contact fatigue strength and bending fatigue strength, and anti-bite ability. The deformation tendency and cracking tendency of nitrocarburizing treatment are very small. Nitrogen carburizing treatment, generally is ** post-process, not allowed to be processed again.
Depending on the selection frequency, the hardening layer range is 0.8~50mm, mainly used for surface hardening. The internal structure is martensite and the surface layer is high residual compressive stress. Surface hardness up to 55~65HRC, with high wear resistance, good contact fatigue strength, good bending fatigue strength and good anti-bite ability. The tendency of deformation and cracking is small. After induction quenching, generally have to go through grinding processing.
The surface hardening layer of flame quenching is generally in 1~12mm and is mainly used for surface hardening. The surface structure is quenched martensite and the surface is under high compressive stress. Surface hardness up to 55~63HRC, high surface wear resistance, good contact fatigue strength, good bending fatigue strength and good anti-bite ability. The tendency of quenching deformation and cracking is small. After quenching the flame, generally have to go through grinding processing. The suitable material for this process is medium carbon steel or medium carbon alloy steel. Mainly used for surface wear - resistant parts.
On 2018-08-08 11:45:46
