site logo

What are the several process methods for crankshaft neck induction hardening?

What are the several process methods for crankshaft neck induction hardening?

1) The crankshaft does not rotate, use an open-close type inductor to heat the journal to be heated, and perform liquid spray quenching. Later, a semi-automatic crankshaft quenching machine tool was developed to perform large quantities of crankshaft neck quenching. The advantage is low labor intensity, but the disadvantage is that the hardened zone is uneven, such as the width of the hardened layer at the top dead point of the connecting rod journal and the bottom dead point. The area is narrow and so on. This process has been used for more than 60 years, and now some automobile crankshafts and tractor crankshafts are still produced using this process.

2) Crankshaft rotation heating, semi-annular inductors are used for mass production on semi-automatic or fully automatic crankshaft quenching machine tools. The advantage is that the temperature of the hardened zone is uniform, and the width is consistent through power pulsation and other technologies. The advantage is that it can be journaled. Fillet quenching, to improve the fatigue strength of the crankshaft, is currently a widely used crankshaft quenching process.

3) The crankshaft does not rotate, and the half-ring main coil is coupled with the half-ring auxiliary coil to heat the crankshaft journal, which is called Sharp-c process. The advantage is that the heating time is short, the heating time of a journal is about 4s, the equipment area is smaller than that of the rotary quenching device, and the inductor has a longer life. However, this process does not solve the crankshaft fillet quenching technology.

4) Crankshaft rotation quenching adopts a double half-ring type inductor, which almost covers the crankshaft journal. The advantages of this process are high heating efficiency and short time. Currently, it is only applied to car crankshafts.