Patent ID: 8598487
Filing Date: 2013-12-03
Classification: B23K

Abstract:
1. A plasma cutting method for cutting a carbon steel plate and for reducing an amount of fumes produced during cutting to be less than 1) the amount of fumes produced during cutting using only oxygen as a plasma gas and 2) the amount of fumes produced during cutting using only oxygen as a plasma gas and only oxygen around a plasma arc, said method comprising the steps of: providing a plasma arc extending from a plasma torch nozzle toward a carbon steel plate for cutting the carbon steel plate; adding at least one gas selected from helium, a hydrogen gas, and a mixture of helium and hydrogen gas to oxygen, wherein said step of adding includes adding the at least one gas in a range of 5 to 40% by volume with respect to the oxygen and supplying a mixed gas as a plasma gas made up of the at least one gas and the oxygen to a periphery of an electrode, and applying a current between the electrode and the plasma torch nozzle or between the electrode and the carbon steel plate, for cutting the carbon steel plate.