| 摘要 |
PURPOSE: To prevent the exhaust gas containing hydrocarbon gas from getting ignited/combusted by adding incombustible gas to the air flowing-in in the laser beam irradiating direction and hydrocarbon gas flowing out from laser beam irradiating part. CONSTITUTION: A steel 11 is irradiated with a laser beam 8 through a nozzle hole 71 of nozzle 7 so as to melt part of the steel 11 and a hydrocarbon gas 9 is supplied to laser irradiating part, carburization is executed to melted part. At this time, for the air flowing-in in the laser beam irradiating direction (a) and the hydrocarbon flowing out from the laser irradiated part (a), incombustible gas (CO, etc.) is added to make an exhaust gas incombustible and then to be exhausted from an exhaust path 12a. By this method, the combustible hydrocarbon gas is safely treated. |
