Tel：0512-65685025
Fax：0512-65650370
Email：sales@hanke-nmc.com
Website：http://www.hanke-nmc.com
Add: Block 7, No.19, Xingnan Road, Wuzhong, Suzhou City, Jiangsu, China
Name：Rebecca Dong
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Technical |
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Causes and preventive measures of mold heat treatment defects. |
1. The mold surface has a soft spot.
The surface has soft spot after heat treatment, which will affect the wearability of the mould and reduce the service life of the die.
The reasons causing
1) the mould has oxidized skin, rust stain and local decarburization before heat treatment.
2) after the mould quenching and heating, the quenching medium is not selected properly, and the impurities in the quenching medium are too much or aging.
Preventive measures
1) the molds and rust spots should be removed before the mold heat treatment, and the surface of the mould should be properly protected when the quenching is heated, and the heating in the vacuum electric furnace, salt bath furnace and protective atmosphere furnace should be used as far as possible.
2) when the mold is cooled and heated, the suitable cooling medium should be selected. The cooling medium used in the long term should be filtered regularly or replaced regularly.
2. The mold is not well organized before heat treatment.
The final spherification of the mould is uneven, the spherification is not perfect, and the tissue has network, ribbon and chain carbide, which will make the die easy to crack after quenching, causing the die to be scrapped.
The reasons causing
1) the original structure of mould steel material has a serious carbide segregation.
2) poor forging process, such as forging heating temperature is too high, small deformation, slow stop forging temperature is high, the cooling speed after forging, etc., make forging organization bulky and mesh, belt and chain carbide exists, the spheroidizing annealing is difficult to eliminate.
3) the spherification annealing process is not good. If the annealing temperature is too high or too low, the isothermal annealing time is short, which can cause the spherification annealing organization or the spheroidization.
Preventive measures
1) in general, according to the working conditions of the mold, the production volume and the strength and toughness of the material itself, we should try to select high-quality steel materials.
2) improve forging process or prepare heat treatment with positive fire to eliminate the inhomogeneity of network and chain carbide and carbide in raw materials.
3) high carbon die steel which can not be forged can be treated with solid solution.
4) set the correct ball annealing process specification for the forging die, and can adopt the tempering heat treatment and rapid uniform spherification annealing.
5) ensure the temperature uniformity of the mold in the furnace.
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Down：Mold injection molding processing center.
Up：Prevent the heat treatment deformation of precision mold. |
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