Predicting Heating and Cooling Times due to Local Preheating

Preheating procedure is applied to prevent cold cracking in steel construction. Then local preheating near the weld line is generally applied, because preheating whole the construction can not be did simultaneously. In case of using electric heaters as means of fecal preheating, the temperature of their heaters can be controlled by sensor fitted on some distance from the weld line. So it is necessary to estimate the temperature on weld line by temperature on the position of sensor.In this report, we derive the theoretical formula that finds the temperature of the other position but weld line during preheating, and cooling temperature and time on the weld line can be estimated by using the calculated values. We compared experimental data under various welding conditions with calculated values.