Method and Equipment for Flame Cutting a Steel Part

A process, employing at least one torch equipped with a cutting nozzle, for oxy-fuel cutting an iron-containing metal workpiece, which proceeds according to the steps of:

• a) preheating a localized region of the workpiece by means of a flame obtained by combustion of a combustible gas and oxygen;
• and
• b) supplying, in the direction of the localized region preheated in step a), gaseous oxygen at a first pressure and/or a first flow rate in order to initiate piercing, whilst at the same time moving the torch in the cutting direction,
• c) after the piercing of the workpiece has been initiated in step b), the pressure and/or the flow rate of the gaseous oxygen supplied in the direction of the region where the piercing started is increased up to a second pressure and/or a second flow rate that one higher than the first pressure and/or first flow rate in order to perforate the workpiece.

An apparatus for oxy-fuel cutting a workpiece, comprising:

• at least one torch equipped with a cutting nozzle;
• at least one source of combustible gas and at least one source of oxygen configured to feed the torch with said combustible gas and said oxygen;
• a gas circuit configured to supply the cutting nozzle with gaseous oxygen;
• and
• characterized in that the gas circuit comprises a main gas line and a bypass line, said main gas line being provided with a pressure/flow rate control device for controlling the pressure/flow rate of the gas in said main channel,
• and wherein the apparatus is adapted to move the torch along the cutting path of the workpiece.