1. Manufacturing accuracy of hardware molds

Uneven and incomplete organizational transformation, as well as excessive residual stress formed by heat treatment, result in deformation of the mold during processing, assembly, and use after heat treatment, thereby reducing the accuracy of the mold and even scrapping.

2. Strength of hardware molds

Improper formulation of heat treatment process, non-standard heat treatment operation, or incomplete condition of heat treatment equipment, resulting in the strength (hardness) of the treated mold not meeting the design requirements.

3. The working life of the mold

The unreasonable organizational structure and excessive grain size caused by heat treatment result in a decrease in the main performance of the mold, such as toughness, cold and hot fatigue performance, and wear resistance, which affects the working life of the mold.

4. Manufacturing cost of hardware molds

As an intermediate or final step in the mold manufacturing process, the cracking, deformation, and performance caused by heat treatment often result in the mold being scrapped, and even if repaired, it can still be used, increasing working hours, extending delivery time, and improving the manufacturing cost of the mold.

It is precisely the close correlation between heat treatment technology and mold quality that promotes and improves each other in the process of modernization. In recent years, the rapidly developing fields of mold heat treatment technology internationally are vacuum heat treatment technology, surface strengthening technology of molds, and pre hardening technology of mold materials.

Vacuum heat treatment technology for hardware molds

Vacuum heat treatment technology is a new type of heat treatment technology developed in recent years. Its characteristics are urgently needed in mold manufacturing, such as preventing oxidation and non decarburization, vacuum degassing or degassing, eliminating hydrogen embrittlement, and improving the plasticity, toughness, and fatigue strength of materials (parts). The slow vacuum heating and small temperature difference between the inside and outside of the parts determine the small deformation of the parts caused by the vacuum heat treatment process.

According to the different cooling media used, vacuum quenching can be divided into: vacuum oil cooling quenching, vacuum air cooling quenching, vacuum water cooling quenching, and vacuum nitrate isothermal quenching. In the vacuum heat treatment of molds, the main applications are vacuum oil cooling quenching, vacuum air cooling quenching, and vacuum tempering. To maintain the excellent vacuum heating characteristics of workpieces (such as molds), the selection and formulation of coolants and cooling processes are very important. The quenching process of molds mainly adopts oil cooling and air cooling.

For mold working surfaces that no longer undergo mechanical processing after heat treatment, vacuum tempering should be used as much as possible after quenching, especially for vacuum quenched workpieces (molds), which can improve mechanical properties related to surface quality, such as fatigue performance, surface brightness, corrosion resistance, etc.

The successful development and application of computer simulation technology for heat treatment processes, including tissue simulation and performance prediction technology, have made intelligent heat treatment of molds possible. Due to the small batch (or even single piece) and multi variety characteristics of mold production, as well as the high requirements for heat treatment performance and the inability to produce waste, intelligent processing of molds has become necessary.

The intelligent heat treatment of molds includes:

1. Clarify the requirements for the structure, materials, and heat treatment performance of the mold;

2. Computer simulation of temperature and stress field distribution during mold heating process;

3. Computer simulation of temperature field, phase transformation process, and stress field distribution during mold cooling process;

4. Simulation of heating and cooling process;

5. Development of quenching process;

6. Automation control technology for heat treatment equipment.

Developed industrial countries abroad, such as the United States and Japan, have already carried out technological research and development in vacuum high-pressure gas quenching, mainly targeting molds.