Temperature Dependence of Flow Strength of Austenitic Stainless Steels and Titanium at Low Temperatures

Abstract

The temperature dependence of the flow strength for two austenitic stainless steels (SUS 304L and 304LN) and one commercially pure Ti (JIS class 2) has been investigated at the temperature range between 4.2 and 77 K. All materials studied exhibited an anomaly in the low temperature dependence of flow strength. 304L steel showed a peak at 24 K on the flow strength versus temperature curve, and 304LN steel showed two peaks at 7 and 40 K. Commercially pure titanium also showed a maximum at 14 K. Magnetic measurements for austenitic stainless steels indicated that the anomalies were not due to the magnetic transition. The anomalies are considered to be due to the dislocation inertial effect on the thermally activation process.