抄録
In the previous report the fatigue deformation limit diagram at room temperature was studied experimentally on the coiled springs of 0.82% C-steel wire. In the present paper the same limit diagram on that of 0.44% C-steel wire is investigated at room temperature and 100°C. The results obtained are as follows;
(1) The fatigue deformation limit at 100°C is remarkably lower than that at room temperature. This may be the result mainly from the over-ageing due to both heating and repeated stress.
(2) From the above result, it is undesirable to use these coiled springs at elevated temperature, even at 100°C. If these springs must be used at 100°C they should be used under the repeated stress condition below the fatigue deformation limit obtained in this investigation.
