Laser hardening method

Abstract

Abstract PURPOSE:To form a desired quench hardening depth by spraying a low temp. gas or liquid upon the back side of a thin steel product in hardening of the product with laser beams. CONSTITUTION:The part of thin steel product 4 to be hardened is irradiated with laser beams 1 while moving product 4 by rotation of rollers 7. At the same time, the back side of product 4 is cooled with low temp. gas 6 such as nitrogen sprayed from nozzle 5. In order to cool the back side, a low temp. liquid may be used or a cooled metal plate may be contacted closely. By being cooled from the back side, product 4 is provided with sufficient heat capacity, and hence it can be quench hardened up to the same limit depth as a semi-infinite body. In addn., product 4 can be considered to be the surface layer part of the body, and by controlling the temp. of gas 6, the whole of product 4 can be quench hardened if the thickness is within 1.6 mm.

Inventors

• 👤 Takio Okuda
• 👤 Megumi Omine
• 👤 Minoru Kobayashi
• 👤 Yoshio Yamane
• 👤 Toshio Yoshida

Bibliographic Details