Effect of finishing temperature (750 ~900 °C ) and product size (Φ12 mm and Φ5. 5 mm) of rod on precipitation of carbide network in bearing steel GCrl5 has been studied. Results show that as railing ① 12 mm rod

with finishing temperature 800 °C

the rating of carbide network is minimum i. e. 1. 5

with decreasing finishing temperature to 750 °C

the rating of carbide network increases to 2. 0 ； as rolling Φ5. 5 mm rod

with finishing temperature 850 °C

the rating of carbide network in minimum i. e. 1. 5

with decreasing finishing temperature to 800°C the rating of carbide network increases again to 2. 5. For the light rod

the too low finishing temperature is not available to inhibit the precipitation of carbide network in steel. Therefore the optimum finishing temperature is related to specification of rolled products.