摘要 |
A process for heat treating a metallic substance (12) comprises passing such metallic substance (12) to be heated to within a predetermined heat treatment temperature range through a controlled heating zone (20). In such zone (20), the metallic substance (12) is passed by electrically powered shortwave infrared radiation sources (28, 30) capable of producing high intensity radiation and whose radiation intensity, which heats such metallic substance (12), can be immediately varied in accordance with input electrical energy thereto. The electrical input energy to the sources is controlled so that their cumulative heating effect brings the temperature of such metallic substance (12) to within said temperature range as such metallic substance (12) leaves said zone. |