1. Controllable atmosphere heat treatment

Controlled atmosphere heat treatment is mainly to prevent oxidation and decarburization, and carburizing and nitriding to achieve accurate control. Since the end of the 1980s, it has been applied in industrial production. Up to now, the speed of development and the wide application are breathtaking.

2. Vacuum heat treatment

Salt bath quenching is limited by the environment, has been the trend of the sunset. The application and development of vacuum heat treatment technology have been further improved and popularized. It has the characteristics of no oxidation, no decarburization, clean and bright surface of the workpiece after quenching, high wear resistance, no pollution and high degree of automation. Vacuum annealing, vacuum degassing, vacuum oil quenching, vacuum water quenching, vacuum air quenching, vacuum tempering and vacuum carburizing are widely used in industrial production. In recent years, with the appearance of high pressure gas quenching vacuum furnace, the vacuum quenching of high speed steel tool has become a reality.

3. Induction heat treatment and ion nitriding heat treatment technology

Induction heat treatment is widely used in automobile industry, engineering machinery, petrochemical industry and other industries with the advantages of high efficiency, energy saving, cleanliness and flexibility. Nearly 40% of automobile parts can be used with induction heat treatment, such as crankshaft, gear, universal joint and half shaft. Using induction heating, many products can be completed automatic or semi-automatic production line, improve the stability of product quality, reduce labor intensity, beautify the working environment. Induction heating power supply has developed rapidly in China, and the old electronic shock tube has completed its historical mission, replaced by the all-transistor. The microcomputer controlled transistor is used to adjust the power supply, which is stable, convenient, high precision and greatly reduces the interference to the power grid harmonics.

4. Quenching medium and cooling technology

The ideal quenching medium should have the following characteristics:

(1) quality: fast cooling at high temperature and slow cooling at low temperature. That is to eliminate cracks and reduce quenching deformation.

(2) environmental protection: no toxic, harmful smoke or gas volatilization, not easy to burn, the workpiece is easy to clean after quenching, no corrosion to the equipment, do not stimulate burn skin.

(3) stable: the properties of the workpiece are uniform and stable after quenching, and the medium itself is stable in a certain period of time.

(4) economic: high quality and high price, low energy consumption.

In recent years, the development of quenching medium is very rapid. The properties of quenching oil have been improved, and the research and application of organic polymer quenching medium have achieved unprecedented development.

5. Adopt new surface strengthening technology and popularize heat treatment of nitrogen-based atmosphere

The original tool surface treatment method is limited to steam treatment, oxygen nitriding and other old methods, generally can only improve the tool life of 30%~50%. Since the 1980s, China has independently developed and introduced QPQ salt bath composite treatment technology and PVD titanium oxide physical coating technology. The former can increase the tool life 2~3 times stably, simple equipment, low cost, especially suitable for dry common tools; The latter can improve tool life 3~5 times, suitable for all kinds of precision and expensive gear tools.

Nitrogen-based atmosphere, used for protection of heat treatment and chemical heat treatment, can achieve no oxidation decarbonization heat treatment, and can avoid heat treatment nitrogen brittleness, nitrogen-based atmosphere chemical heat treatment, can reduce internal oxidation and other defects, improve the quality of chemical heat treatment.