鐵鋼のサブゼロ處理 : 理論と應用

概要

論文の詳細を見る
In industry of Japan, the sub-zero treatment are widely discussed recently and applied to the manufacture of the ball and roller bearings, tools, gears, etc. The theory and the application of the sub-zero treatment of the steel are briefly outlined as follows. (1) The retained austenite of the quenched steel can be decomposed by the sub-zero chilling and the hardness of the steel becomes higher and uniform. (2) The retained austenite decomposes isothermally at room temperature and the length of the steel changes. To prevent the secular change of the length, the gauge or the ball bearing is cooled to the freezing temperature and tempered sufficiently. Thus treated, the change of the length becomes smaller than 10^<-6> of the initial dimension after one year. (3) The mechanical properties of the steel are improved by the sub-zero treatment of the proper cooling temperature. The impact value of the bearing steel or the life of the tool increases by this treatment. (4) Stabilization and the transformation of the retained austenite are discussed. The stability increases when the α martensite is decomposed, while it decreases when the precipitation occurs. (5) Sub-zero treatment is applied to the magnetic steel and the case-hardening steel.
社団法人日本鉄鋼協会の論文
1954-06-25