Process analysis of heat treatment of hollow shaft using medium frequency induction heating machine

The hollow shaft generally refers to a through hole formed in the center of the shaft body, and an internal keyway is opened in the through hole. The outer surface of the shaft body is processed with a stepped cylinder, and an external keyway is opened. The center through hole of the shaft is in contact with the press. The main shaft of the chamber is sleeved, and the input power drives the shaft through the transmission gear installed on the cylinder on the surface of the shaft body and is directly transmitted to the main shaft of the pressing chamber. During the operation of machinery, the hollow shaft has to bear huge friction. Therefore, many manufacturers often use medium frequency induction heating machines for quenching heat treatment. Today, the editor will take the hollow shaft on the Dongfanghong LF80-90 tractor as an example to briefly introduce the medium frequency quenching process.

The main clutch shaft part (5125350, also known as the hollow shaft) on the Dongfanghong LF80-90 tractor is a hollow shaft with a thin wall. It is easy to be quenched during traditional heating and quenching, resulting in excessive deformation. For this reason, a medium frequency induction heating machine is used for heat treatment, and the effect is very good.

The main clutch shaft on the Dongfanghong tractor uses a medium-frequency induction heating machine of 8000Hz and 160kW. The quenching process is: the two splines are quenched by medium frequency and then tempered by medium temperature (medium temperature tempering temperature is 320℃±10℃, 90min). After tempering, they are air-cooled. The hardness requirement is 42-48HRC, and then the medium frequency at the two optical axes in the middle is Quenching, then tempering after quenching (tempering temperature is 160℃±10℃, 120min, hardness is 52-57HRC). In particular, it should be pointed out that before this part is quenched, a plug needs to be driven into the spline end to prevent quenching deformation.

The heat treatment process is a key factor affecting the quality of the workpiece's heat treatment. Therefore, it is very important to master the heat treatment process of the workpiece. Today, this article briefly introduces the medium frequency heat treatment process of hollow shafts. I hope it can be helpful to your heat treatment work.