High-frequency induction heating machine can effectively solve the heat treatment defects of tank barrels

The tank gun barrel is a key part of the tank firepower system. The workpiece material is required to have high strength and toughness, impact resistance, good comprehensive mechanical properties, and high heat resistance and corrosion resistance. The tank barrel material is 35CrNi3MoV steel. The barrel diameter is 335mm and the length is 6530mm. After the barrel is forged, the heat treatment uses white spot prevention annealing, normalizing and quenching and tempering. During production, it was found that due to improper forging and heat treatment processes, mixed crystals and coarse grain defects occurred many times, resulting in a significant decrease in the toughness of the gun barrel, resulting in substandard products, seriously affecting military production, and causing large economic losses. After analyzing the causes of the defects, it was found that after heat treatment using a high-frequency induction heating machine, the barrel performance was good and could meet the working requirements.

Inspection and analysis show that the mixed crystal defects that appear after the quenching and tempering treatment of 35CrNi3MoV steel gun barrels are caused by the structural inheritance of the steel. The higher the degree of alloying of steel and the faster the heating rate, the more likely it is that structural genetic defects will occur in the steel. To prevent genetic defects in the tissue, process measures should be taken to transform the original non-equilibrium tissue into a balanced tissue. Production tests show that using a high-frequency induction heating machine to perform three processes: complete annealing, incomplete annealing, and high-temperature tempering at a slightly lower A1 temperature to complete recrystallization and obtain a balanced structure, can avoid and eliminate mixed crystal defects. After the quenching and tempering treatment, the recrystallized equilibrium structure of the 35CrNi3MoV steel gun barrel has a refined structure and excellent performance, which fully meets the technical performance index requirements of the gun barrel and has obvious technical and economic benefits.

This article only introduces the use of high-frequency induction heating machines for complete annealing, incomplete annealing and high-temperature annealing to complete the recrystallization of tank barrels and obtain a balanced structure. The specific heat treatment operation process is not described at all. If you don’t understand anything about the heat treatment process, you can read more books on heat treatment. I believe you will gain a lot.