Let's take a look at the medium-frequency heat treatment process of type II spring bars using medium-frequency induction heating machines for quenching

Type II elastic fasteners are composed of spiral spikes, gauge baffles, rubber pads, nylon baffle seats and washers. They are used for installation on standard gauge railway straight lines and curves with a radius of not less than 300mm. On the concrete sleepers of the track line, the purpose is to connect the rails and the concrete sleepers to maintain the standard gauge of the distance between the two rails. During its service, it must withstand repeated compression and impact. Therefore, type II elastic strips require high hardness, wear resistance and service life. Nowadays, many manufacturers use medium frequency induction heating machines to quench and heat treat Type II spring bars to meet their working needs. Today, we will take a look at the medium-frequency heat treatment process of type II elastic strips.

The type II spring bar material is 60Si2MnCrA hot-rolled spring round steel with a diameter of 13mm. The metallographic structure after heat treatment is required to be uniform tempered trotenite, and a trace amount of intermittent ferrite is allowed in the center; the hardness is 42~47HRC; residual Deformation ≤1mm; fatigue test 5 million times without breaking, etc. We analyzed the heat treatment performance of 60Si2MnCrA hot-rolled spring round steel. Its AC3 is 770℃, the quenching temperature is selected at AC3+(30~50)℃, and the temperature of the spring bar after being heated through medium-frequency induction heating by a medium-frequency induction heating machine reaches 950~1050℃, medium frequency induction heating uses medium frequency induction heating equipment. The elastic strip is put into the inductor made of hollow copper tube, and the heating is carried out in the quartz glass tube in the middle of the inductor. Since the inductor is long , ensuring uniform temperature inside and outside the elastic strip. After being formed by the I, II, and III presses, the overall temperature of the elastic strip dropped to 800-850°C, which is in the heating temperature area required by the normal quenching heat treatment process of the elastic strip. Therefore, the waste heat temperature after forming is used to quench the oil. Medium cooling, then using a clamp to compress the spring bar, and then tempering heat treatment.

Type II elastic bars are an important part of the railway, and their heat treatment quality has an important impact on the entire railway. Today, we briefly introduce the medium frequency heat treatment process of Type II elastic strips. We hope it will be helpful to your work. Of course, if you have other opinions about heat treatment, you can also discuss and communicate with us.