Cutting of thick steel plate by 5kW CO laser beam

Abstract

Due to its capability of achieving high powers, the CO2 laser is widely used for various material processing applications, especially welding and cutting of thick steel plates.At the same time, lasers of shorter wave lengths are being demanded to meet the expectation of better quality and productivity in material processing because shorter wave lengths lead to increased absorption of the laser beam by metal surfaces and smaller spot sizes.With the viewpoint of satisfying the requirements of both shorter wave length and high power, we have developed a high power CO laser whose wave length of around 5 μn is intermediate to that of YAG (1.06μm) and CO2 (10.6μm) lasers.This paper outlines the result of the first cutting trials performed on thick steel plate with the newly developed 5kW CO laser. Using oxygen as the assist gas and a standard cutting nozzle, SUS 304 stainless steels up to 55mm thickness could be cut with this laser.Since our study is still in the initial stages, there remain some uncertain factors such as the effect of beam quality on materials processing. But it is apparent that the CO laser beam has superior cutting capability and wide applicability to various materials processing applications.Due to its capability of achieving high powers, the CO2 laser is widely used for various material processing applications, especially welding and cutting of thick steel plates.At the same time, lasers of shorter wave lengths are being demanded to meet the expectation of better quality and productivity in material processing because shorter wave lengths lead to increased absorption of the laser beam by metal surfaces and smaller spot sizes.With the viewpoint of satisfying the requirements of both shorter wave length and high power, we have developed a high power CO laser whose wave length of around 5 μn is intermediate to that of YAG (1.06μm) and CO2 (10.6μm) lasers.This paper outlines the result of the first cutting trials performed on thick steel plate with the newly developed 5kW CO laser. Using oxygen as the assist gas and a standard cutting nozzle, SUS 304 stainless steels up to 55mm thickness could be cut with this laser.Since our study is still in the initial stages, there remain some uncertain fact...