材料期刊网

Grain growth kinetics of austenite in a hypoeutectoid steel (containing 0.35 wt% carbon) at 920°C and in a hypereutectoid steel (containing 1 wt% carbon) at 980°C has been investigated with holding time ranging from 1 h to 6 h. The hypoeutectoid steel exhibited normal grain growth without solute drag hindrance with a time exponent (0.51) close to the theoretical value (0.5). However, grain growth of austenite in hypereutectoid steel was extremely slow up to 3 h of holding characterized by a low value of time exponent (0.06). Thereafter, a breakaway occurred and the grain growth in hypereutectoid steel from 3 h to 6 h of holding progressed normally with a time exponent (0.55) close to the theoretical value (0.5).