The large runner plate is a bottleneck of complete localization of China-made hydrogenerator.25CrMo4 is used for a China-designed runner plate of 700MW hydrogenerator.To ensure hardness uniformity of runner surface is one of the main technical difficulties.The effects of forging temperature,strain,strain rate,temper temprature and depth of quenching on microstructure and hardness uniformity of 25CrMo4 were investigated by simulation forging and heat-treating test.The result shows that high strain rate of fo...