真空浸炭における雰囲気制御の実際;真空浸炭における雰囲気制御の実際;Atmosphere Control during Low-Pressure Carburizing

Abstract

Atmosphere control during low-pressure carburizing is important from a quality assurance viewpoint. We have developed a lowpressure carburizing furnace that can be used for mass production, which has an atmosphere control system comprising a thermal conductivity hydrogen sensor and an oxygen sensor. The hydrogen sensor is used for providing an atmosphere control necessary for carrying out both low-pressure carburizing and carbonitriding processes. The oxygen sensor detects air leaks and sooting in the furnace. In this paper, we demonstrate that when the atmosphere during the low-pressure carburizing and carbonitriding processes is controlled using the hydrogen sensor, the amount of carbon and nitrogen inˆltrated into the steel parts can be controlled, even if the parameters such as the ‰ow rate of gases, temperature, and the surface area of the parts change.