Square rectangular tubes are popularized and applied with high-pressure air-cooling quenching technology. Foreign heat treatment manufacturers pay more attention to the cooling during heat treatment of
rectangular tubes. According to the technical requirements of structural alloy steel pipes, we can perform slow cooling, oil quenching and one-time gas quenching. The rapid atmosphere circulation cooling uses a high-pressure gas spray to the cooling chamber. The computer controls the changes in flow rate and flow rate to achieve the normal cooling rate in a specific time, so as to achieve the cooling curve required during the heat treatment process of the rectangular tube. Actual quality of heat treatment of structural alloy steel pipes. The quenching gas previously cooled by the rectangular tube gas quenching method is nitrogen and helium. When the jet is strongly realized with air, the structural alloy steel pipe is cooled at a very rapid rate, and the surface after quenching will have an extremely thin oxide color film, showing a beautiful appearance of gray-white structural alloy steel pipes, which saves a lot of nitrogen and inert gases, and further reduces the cost of heat treatment.
The combination of vacuum low-pressure carburizing and high-pressure gas quenching is an advanced carburizing and quenching process. It has a fast carburizing speed, excellent carbide structure, small quenching cracking deformation, energy saving and carburizing agent raw material structure The surface quality of alloy steel pipes is good, which is beneficial to environmental protection and other features. Hot place of rectangular tube ,the processing equipment adopts oil cooling to realize fan cooling. All the cooling devices are oil-sealed self-cooling, which completely replaces the water cooling cycle related systems. The entire heat treatment furnace does not use any cooling water. The water in the quenched oil tank plate heat exchanger of the rectangular tube is replaced with cooling oil. The cooling oil starts to heat up due to the heat exchange of the hot oil. The change in the specific gravity of the oil will cause the cooling oil to circulate. The heat sink cooperates with the fan to achieve full oil cooling effect, which can save a lot of cooling water.
