Abstract: Drawing method of Bergerhord curve under the actual cooling condition and the material selection method based on Bergerhord curve were studied. After quenching test, the Bergerhord curve under the actual cooling condition is obtained by combing the hardenability curve of the material, based on which the end quenching point at 3R/4 of the deputy box spindle with the same cooling rate is calculated as J25 mm. The actual production results show that the Bergerhord curve obtained by this method is reliable and scientific for material selection.

Key words: Bergerhord curve, quenching, cooling