表面処理・腐食
大気圧プラズマジェット窒化法による処理面積の拡大化
2022 年 108 巻 6 号 p. 354-359
詳細
2022 年 108 巻 6 号 p. 354-359
A unique nitriding technique using the atmospheric-pressure plasma jet has been upgraded by extending the treatable area. The previous manner to heat up a steel sample was spraying the thermal plasma jet onto the sample surface, which could maintain the treatment temperature only within a limited area of sample to restrict the treatable area to ca. 300 mm2. Here, we first introduced an external heating system to the plasma-jet nitriding to control the treatment temperature of a larger sample. As a result, the treatable area is successfully extended to ca. 6300 mm2. Moreover, the lifetime of NH radicals produced by the plasma chemical reaction is found to be long enough to cover the relevant area, implying the importance of NH for plasma-jet nitriding.
