A study on the improvement of interface heat transfer coefficient for hot forging

열간단조시 계면열전달계수의 신뢰성 향상에 관한 연구

The temperature difference between die and workpiece has been frequently caused to various surface defects. The distribution and change for the temperature of forged part should be analyzed to prevent the generation of various defects related with the temperature. The surface temperature changes were mainly affected by the interface heat transfer coefficient. Therefore, the coefficient is necessary to predict the temperature changes of die and workpiece. The temperature calculated by FEM result might be well compared with the measured temperature. However, it is impossible to measure directly the temperature distribution of forged part. Therefore, the comparisons between measured temperature and predicted values are preformed by the microstructure in various temperature. Since the differences of microstructure could be obvious, the temperature criteria is set near by the incipient melting temperature. The predicted temperatures are well coincided with the measured values.