Current status of foreign heat treatment technology and heat treatment equipment

1. Current status of heat treatment technology
(1) Promote the application of high-pressure air quenching

Foreign heat treatment manufacturers attach great importance to cooling during the heat treatment process. According to the technical and technological requirements of the product, slow cooling, oil quenching, and one-time gas quenching can be performed. Rapid atmosphere circulation cooling uses high-pressure gas injection into the cooling chamber, and the computer controls the flow rate and flow rate changes to achieve the cooling rate within a specific time, thereby achieving the required cooling curve during the heat treatment process and ensuring the heat treatment quality of the parts. In the past, the quenching gas used in the gas quenching method was nitrogen, helium, etc., but now it is strongly sprayed with air to cool the workpiece at a very rapid rate. After quenching, the surface has only a very thin oxide film, which is off-white, and the color of the parts is still beautiful. , And save a lot of nitrogen and inert gas, so that the cost of heat treatment is further reduced.

The combination of vacuum low pressure carburizing and high pressure gas quenching is an advanced carburizing and quenching process today. It has fast carburizing speed, excellent carbide structure, small quenching cracking and deformation, energy saving and carburizing agent raw materials, carburized parts The surface quality is good and it is conducive to environmental protection.

(2) The heat treatment equipment adopts oil cooling

Fan cooling, heat exchanger cooling, quenching oil tank cooling and other cooling devices all adopt oil-sealed self-cooling, completely replacing the water-cooling circulation system, and the entire heat treatment furnace does not require any cooling water. For example, hot air circulation fan cooling: change the inlet and outlet pipes of the original water cooling jacket to oil pipes, and place a small oil tank with a diameter of 102mm near the fan. The oil cooling system is fully enclosed. When the fan bearing heats up, the proportion of heated oil is small. , Naturally float upward, causing natural circulation of oil. In the case of oil storage in a small oil tank and natural heat dissipation, the hot oil is added to the circulation after being cooled, so as to completely replace water cooling without fuel consumption and no power. The water in the plate heat exchanger of the quenching oil tank is replaced with cooling oil. The cooling oil is heated by the heat exchange of the hot oil. The change in the specific gravity of the oil causes the cooling oil to circulate by itself. A heat sink is added to the oil tank on the top of the furnace to match the fan. It can achieve the effect of full oil cooling and save a lot of cooling water.

(3) Hydrogen probe is used on the nitriding furnace

The German company Ipsen has applied hydrogen probes and corresponding technologies to measure and control the nitrogen potential in the nitriding furnace to adjust and control the atmosphere of the nitriding furnace and realize the modernization of the nitriding furnace.

(4) Gas radiant tube

At present, most of the heat treatment equipment in Europe has adopted gas radiant tubes and natural gas heating. Gas heating technology and equipment are very mature in Europe. Natural gas burners have a standard series, which are manufactured and supplied by professional burner factories. The inner tube of the gas radiant tube is replaced with ceramics to extend the service life and increase the power. Natural gas heating improves energy utilization and reduces production costs.