| 摘要 |
PURPOSE:To improve wear resistance, by transferring arc heat source or material to be treated at a prescribed speed while the material to be treated, aluminum or its alloy, being melted by the arc heat in a mixed gas of inert gas and nitrogen gas, and by varying the arcing conditions. CONSTITUTION:Arc heat source or material to be treated, aluminum or its alloy, is transferred at <=20mm./sec speed while the material to be treated being melted with the arc heat in a mixed gas atmosphere composed of nitrogen gas and inert gas such as argon, helium, so as to harden the desired part, and is cooled with gas or water at need. When the temp. of the material to be treaed rises even when it is cooled, molten nitride is overheated, hence arc current is decreased to a smaller value than the initial current (25% minimum). The value is determined in relation to the transferring speed of the arc heat source or the materia to be treated. Hereby the surface state of the nitrided surface is improved, and excellent wear resistance is given to the material. |
