摘要 |
A material heating method includes: a step of charging a silicon-containing carbon steel material into a heating furnace; a step of preheating the material; a first heating step of raising the temperature of the material; a second heating step of lowering the temperature of the material so as to reduce a temperature difference between the surface and inside of the material; a third heating step of raising the temperature of the material; and a soaking step of reducing the temperature difference between the surface and inside of the material. The temperature of the material in the heating furnace is maintained at the melting point of fayalite or lower. |