To provide a method for evaluation of surface work cracking sensitivity during cold forging of a column material to be worked which is capable of appropriately evaluating work cracking sensitivity during the cold forging of the column material to be worked formed by cutting a bar steel material into a predetermined dimension without using a press device with large compression load.
In the method for evaluation of surface work cracking sensitivity during the cold forging of the column material to be worked, a composite body is made by assembling a solid body comprised of a metal material having tensile strength equal to or less than 1/2 of tensile strength of a bar steel material into a hollow specimen satisfying 0.5≤inner diameter d/outer diameter D≤0.95, formed by cutting the bar steel material orthogonally to a rolling direction, and hollowing out a center part. The composite body is upsetted in a height direction, and a critical upsetting ratio (εhi) is obtained from the cracking generation state at the outer surface of the composite body, and surface work cracking sensitivity property during the cold forging of the column material to be worked formed by cutting the bar steel material is evaluated based on the critical upsetting ratio.
TODA MASAHIRO
NARUMIYA HIROKI
MIYANISHI KEI
| JP2013103238A | 2013-05-30 | |||
| JP2013142559A | 2013-07-22 | |||
| JP2005120432A | 2005-05-12 | |||
| JPS63264237A | 1988-11-01 |
Shunta Naito