Journal Published Online: 19 September 2019
Volume 8, Issue 1

Holistic Problem of Cooling Effect of Vertically Oil-Quenched Shaft-Type Workpiece



During the process of vertical oil quenching, the sides of a shaft with the same effective thickness often do not obtain the same quench cooling effect. Therefore, the quench cooling effect of such workpieces can only be described with the distribution of measured values on the whole surface instead of measured values at individual spots. This is the holistic problem of the quenching effect of such workpieces. The main hazard caused by this type of holistic phenomenon is the creation of serious and regular uneven longitudinal quenching hardness, from inside out on the shaft. The holistic problem is caused by two factors: (1) the gas flow within the vapor blanket and (2) the order of the transition of vapor blanket to nucleate boiling on the surface of the workpiece. Through experimental observation, analysis, and inference, a general model is summarized for the holistic problem of workpieces with shafts of different lengths in the quenching process. By using the general model and the law disclosed by it, a new technique is developed to solve the holistic problem of the workpieces. With the new technique, higher and more uniform quenching hardness can be achieved, the quenching period of the workpiece can be shortened substantially, and steels with lower hardenability can be used to make the workpieces and achieve the same hardening effect. Moreover, oil quenching can replace induction quenching and achieve the same case hardening effect. By comparing the characteristics of the holistic problem and the distortion problem of workpieces in quenching, we arrived at two inferences: (1) quenching distortion and the holistic phenomenon have the same driving factors and (2) quenching distortion is just one of the detriments caused by the holistic problem. Therefore, the quenching distortion problem of most workpieces can be solved by the angle of their holistic problems.

Author Information

Zhang, Kejian
Beijing Huali Fine Chemical Co. Ltd., Beijing, China
Wang, Shui
Beijing Huali Fine Chemical Co. Ltd., Beijing, China
Hao, Xuezhi
Beijing Huali Fine Chemical Co. Ltd., Beijing, China
Pages: 18
Price: $25.00
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Stock #: MPC20190084
ISSN: 2379-1365
DOI: 10.1520/MPC20190084