火炎焼入れに関する研究 (第1報)

各種焼入条件に伴う硬化層の適性

抄録

This study is to find suitable flame-hardening conditions and also to see the wear resistance of metal by using as a testpiece Ca Kugelpraphite Gusseeisen flame-hardened by progressive hardening method.
The flame-hardening has so far been known as comparatively easy method, but is now being recognized as a reasonable method of hardening because the direct measuring of surface temperature has been made possible recently by the appearance of Milliscope and by the progress of hardening equipments in western countries.
In this study, we observed the quality of hardened layers and measured the hardened degrees of surfaces under the various suface temperatures made by changing the Feed Speed, Gas Pressure and Pre-Heating conditions of Acetylen-Oxygen Gas. Thus, we got the suitable flame-hardening conditions of Ca Kugelpraphite Gusseeisen and made actual measurings of the wear-resistance.
From these investigations, we understand that comparatively low degrees of temperature for 800°C-830°C are good for hardening in the mechanical quality as well as in the wear-resistance.Also, we got a conclusion that the flame-hardening is better than Salt Bath Nitriding method of the same cast iron testpiece when compared in the wear-resistance.