Advanced heat treatment technology

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With the development of science and technology, the metal heat treatment technology is also constantly improving. The old heat treatment methods will cause certain pollution to the environment, and this will pose a threat to human health. Modern science and technology will improve the heat treatment technology, and then share the first heat treatment technology for you to use.

1. controlled atmosphere heat treatment
Controlled atmosphere heat treatment is mainly to prevent oxidation and decarburization, and to achieve accurate control of carburizing and nitriding. In the late 1980s, it began to be used in industrial production, and now it is widely used. Combined with the characteristics of the Chinese market, domestic and foreign equipment manufacturers have launched new controllable atmosphere heat treatment furnaces of various grades and functions. The large-scale sealed box type multi-purpose furnace of Epson company and the full-automatic intelligent sealed box type multi-purpose furnace production line of Fengdong can not only meet the requirements of carburizing and carbonitriding, but also realize various heat treatment processes such as bright quenching and bright annealing. All of them can realize a series of work, such as computer aided design, production management, logistics management, field control, quality management, process management, etc. At the same time, it changed the situation of “dirty, disordered and poor” in the past heat treatment workshop, and replaced it with simple and bright.
Of course, these production lines are expensive and suitable for mass production, such as the automobile industry. Domestic manufacturers are more close to user requirements, targeted to launch a variety of affordable, diverse styles, superior performance of controllable atmosphere furnace. Most of them can achieve the optimization, prediction and precise control of carbon concentration distribution, obtain the ideal concentration distribution and infiltration layer organization, realize computer management, and have simple menu design and friendly human-computer interface.

2. Vacuum heat treatment
Vacuum heat treatment is a new type of heat treatment technology combining vacuum technology and heat treatment technology. The vacuum environment of vacuum heat treatment refers to the atmosphere environment lower than one atmospheric pressure, including low vacuum, medium vacuum, high vacuum and ultra-high vacuum. Vacuum heat treatment actually belongs to atmosphere controlled heat treatment. The application and development of vacuum heat treatment technology has been further improved and promoted. It has the characteristics of no oxidation, no decarburization, clean and bright surface of workpiece after quenching, high wear resistance, no pollution and high degree of automation. The heat treatment technologies of vacuum annealing, vacuum degassing, vacuum oil quenching, vacuum water quenching, vacuum gas 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 tools has become a reality. There are many vacuum furnace manufacturers, such as Epson company, French ECM industrial furnace company, G-M company, etc. There are many well-known brands of domestic manufacturers, such as “Great Wall” series of China Aerospace Group, WZ series vacuum furnace of Beijing Institute of mechanical and electrical engineering, etc., whose technical level, performance and price have a strong competitive advantage in China, and vacuum heat treatment will become one of the most popular and main technologies in heat treatment workshop.

Vertical Vacuum Gas Quenching Furnace

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, cleaning and flexibility. Nearly 40% of auto parts can adopt induction heat treatment, such as crankshaft, gear, universal joint, half shaft, etc. With induction heating, many products can be processed into full-automatic or semi-automatic production lines to improve the stability of product quality, reduce labor intensity and beautify the working environment. Induction heating power supply is the fastest growing power supply in China. The old electronic shock tube has completed its historical mission and replaced by full transistor. The microcomputer controlled transistor is used to regulate the power supply, which is stable, convenient and precise, and greatly reduces the interference to the harmonic of the power grid. The solid-state high-frequency heating device developed in recent years has obvious advantages. It no longer uses expensive, vulnerable and energy consuming electronic tubes, anode step-up transformers, anode water jackets, filament regulators, etc., but instead uses MOSFET Power electronic devices: it saves one-third of the electricity and one-half of the water. The quenching machine tool matched with the heating power supply has also made great progress. Reflected in:
① the number of manufacturers of machine tools increased significantly.
② the accuracy, stability and automation of the quenching machine are greatly improved.
③ the technical level of targeted professional quenching machine tools has been brought into play.

Ion nitriding technology is characterized by clean surface, corrosion resistance, small deformation and high wear resistance. Compared with gas nitriding, it has the advantages of short cycle, high efficiency and less pollution. In recent years, the development of ion nitriding is very fast, especially the appearance of pulse power supply for ion nitriding furnace. It separates the physical parameters of discharge (voltage, current, air pressure) from the temperature control parameters (pulse width). It increases the adjustability of the process, and is easy to realize the selection and precise control of the process parameters.

4. quenching medium and cooling technology
The ideal quenching medium should have the following characteristics:
① quality type: fast cooling in high temperature stage and slow cooling in low temperature stage. That is to eliminate cracks and reduce quenching deformation.
② environmental protection type: no toxic or harmful smoke or gas volatilization, not easy to burn, easy to clean after quenching, no corrosion to equipment, no stimulation to burn skin.
③ stable type: after quenching, the performance of the workpiece is even and stable, and the medium itself is stable in a certain period of time.
④ economic type: 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 reached unprecedented development. There are American Houghton company, Derun treasure company and British Pb oil company abroad. Domestic Beijing Huali fine chemical company, Nanjing Kerun fine chemical company, etc.

5. Adopt new surface strengthening technology and promote heat treatment in nitrogen based atmosphere
The original tool surface treatment method is only limited to steam treatment, oxygen nitriding and other old methods, which can only improve the tool life by 30% ~ 50%. Since 1980s, China has independently developed and imported QPQ salt bath composite treatment technology and PVD titanium oxide physical coating technology from abroad. The former can steadily increase the tool life by 2-3 times, the equipment is simple and the cost is low, so it is especially suitable for ordinary cutting tools; the latter can increase the tool life by 3-5 times, which is suitable for all kinds of precision and valuable gear cutting tools.

Nitrogen based atmosphere is used to protect heat treatment and chemical heat treatment, which can realize non oxidative decarburization heat treatment, avoid nitrogen embrittlement in heat treatment, reduce internal oxidation and improve the quality of chemical heat treatment.

Vacuum Oil Quenching Furnace