| 摘要 |
PURPOSE:To perform selective hardening of very small steel parts without sticking of Ag oxide with good productivity in the stage of dipping the prescribed part of the steel material into the heated Ag and hardening the steel material by heating the Ag with laser light and providing a shielding plate on the surface of the Ag bath. CONSTITUTION:The required part of a very small steel part is dipped in an Ag bath 1 in a vessel 2 covered circumferentially with a heat insulating material 3 and is thereby heated. The part is drawn from the bath and is hardened by air cooling. The heating of the bath 1 is preferably accomplished by laser light. A cavity is provided to the material 3 and a light beam 5 from a light beam generator 6 is irradiated to the vessel 2, thereby heating the bath 1. A shielding plate 7 provided with a hole for insertion of a member 4 is floated on the surface of the bath 1 and the member 4 is inserted through the hole, by which said member is hardened and the oxidation of the bath 1 is prevented. |
