Abstract
Temperature analysis based on temperature-dependence of thermal properties (specific heat and thermal conductivity) is carried out using numerical calculations. An explicit form of finite difference method was adopted; for constant thermal properties, target size effect is strong compared with the case where properties vary with temperature. For the same sizes, the target of properties varying with temperature is heated more rapidly than that whose properties are independent of temperature; for 2.08 mm radius and 1.06 mm thickness carbon steel, times required to raise the temperature at center point by 1 300 K by a beam of 1 kW power and 1 mm radius are 2.78 and 1.77 ms for the former and the latter, respectively. Under a fixed treatment time, isothermal planes extend more widely in the target whose properties depend on temperature than in that of constant properties. To obtain heat treatment conditions, the consideration based on temperature-dependence of thermal properties must be done.
