Low hardenability steel gears are subjected to induction quenching heat treatment using ultrasonic induction quenching equipment

As a commonly used part in machinery, gears are made from a variety of raw materials, such as carbon steel, low-hardenability steel, stainless steel, etc. Gears of whatever material are required to have high hardness and wear resistance, so many manufacturers use ultrasonic induction quenching equipment for quenching heat treatment to meet their performance requirements. Different materials have different heat treatment processes. Today, Zhengzhou Gou's technical staff will talk about gear induction quenching of low-hardenability steel.

The so-called low hardenability steel refers to a steel type whose hardenability is lower than that of ordinary carbon steel. It reduces the Mn and Si content in high-quality carbon steel with a carbon content of 0.55%-0.70%, changes the deoxidation process, and adds a small amount of Ti as a modifier to refine the grains, increase hardness, and reduce hardenability. . Due to its low hardenability, even if all the gear teeth are heated and then cooled in water or sprayed with water, only the surface of the teeth can be hardened, but the core will still have a non-martensitic structure, so it can be used This feature is used to obtain a hardened layer with approximate tooth profile distribution. Therefore, the essence of gear quenching of low hardenability steel is induction diathermy quenching. Under the premise of ensuring the surface hardness of the steel after quenching, in order to make the steel have low hardenability, the content of impurity elements or alloying elements (such as Cr, Ni, Nn, Si) in the steel that can shift the C curve to the right must be limited. to reduce the hardenability of steel.

Heating specifications for low-hardenability steel: heating time 30-120s, heating speed 10~20℃/s, power density 0.02~0.2kW/cm2, equipment power is 1/10 of conventional induction heating.

The characteristics of low-hardening steel induction hardening are: The low-hardening steel induction hardening process is suitable for complex workpieces, such as gears, bearing rings and transmission cross shafts. The grain size of low-hardened steel is grade 11-12, while the grain size of general steel is grade 7-8. Grain refinement improves the brittle fracture resistance by 5-10 times. After overall heating surface quenching, the residual compressive stress on the workpiece surface can reach 600MPa, which enhances the ability to resist fatigue fracture and increases the life of the workpiece by 7 to 8 times. Using water as a quenching agent can be used for steels with different carbon contents (0.2% to 1.2%), and even for steels with a carbon content of 1-5%. It can be produced online; low-quenched steel saves a lot of alloy elements than carburized steel. For example, the Dongfanghong-75 tractor end drive passive gear (module 6.5mm, number of teeth 60, tooth width 74mm) is made of 65DTi steel. After being heated by ultrasonic induction heating equipment, its hardened layer distribution ratio is 3mm. The gear is more uniform, with a surface hardness of 58 to 62 HCR and a core hardness of 30 to 40 HRC. Therefore, the teeth have high overall strength and toughness, especially the hardening at the tooth root, which is suitable for heavy-duty gears that require bending strength and bending fatigue. Particularly important.

Zhengzhou Gou's is a manufacturer specializing in the production of ultrasonic induction quenching equipment. The equipment it produces is small in size, easy to operate, energy-saving and environmentally friendly. We have been engaged in the production and sales of induction heating equipment for fifteen years and have a good understanding of the heat treatment of workpieces. If you want to know more Please call for more detailed information.