| 摘要 |
PROBLEM TO BE SOLVED: To harden a cylindrical body by increasing its temperature surely, when the cylindrical body is press-molded in the hot or warm state.SOLUTION: A metal cylindrical body set in a press molding machine is energized and heated, and when the temperature of the cylindrical body reaches a Curie point, a voltage is heightened to raise the temperature of the cylindrical body to the A3 transformation temperature or higher. Water is supplied into the cylindrical body, and the cylindrical body is filled with steam by evaporation of water. The cylindrical body filled with steam is press-molded.SELECTED DRAWING: Figure 5 |
