On 2018-08-08 14:48:54
vacuum heat treatment technology in mould industry application
The successful development and application of computer simulation technology of heat treatment process (including organization simulation and performance prediction technology) makes intelligent heat treatment of die possible. Due to the characteristics of small batch (even single piece) and multi varieties of mold production, as well as the high requirements for heat treatment performance and the feature of no waste products, intelligent processing of mold is necessary. Intelligent heat treatment of mould includes: defining the requirements of mould structure, material and heat treatment performance: computer simulation of temperature field and stress field distribution in mould heating process; computer simulation of temperature field, phase change process and stress field distribution in mould cooling process; simulation of heating and cooling process; formulation of quenching process; automatic control technology of heat treatment equipment. Foreign developed countries, such as the United States and Japan, have carried out technical research and development in the field of vacuum high-pressure gas quenching, mainly aiming at the mold.
According to the different cooling medium, vacuum quenching can be divided into vacuum oil cooling, vacuum air cooling, vacuum water cooling and vacuum nitrates isothermal quenching. The main applications of vacuum heat treatment of die are vacuum oil quenching, vacuum air quenching and vacuum tempering. In order to maintain the excellent characteristics of vacuum heating of workpieces (such as dies), it is very important to select and formulate the coolant and cooling process. Oil cooling and air cooling are mainly used in the process of die quenching.
Vacuum heat treatment technology is a new type of heat treatment technology developed in recent years. It has the characteristics that are urgently needed in mold manufacturing, such as preventing oxidation and non decarburization, vacuum degassing or degassing, eliminating hydrogen embrittlement, so as to improve the plasticity, toughness and fatigue strength of materials (parts). Due to the slow vacuum heating and the small temperature difference between the inside and outside of the parts, the deformation of the parts caused by the vacuum heat treatment process is small.
For the die working surface which is no longer machined after heat treatment, vacuum tempering should be used as much as possible after quenching, especially for the workpiece (die) which is vacuum quenched. It can improve the mechanical properties related to the surface quality. Such as fatigue property, surface brightness, corrosiveness, etc.