Instantaneous scarfing by means of a pilot puddle

A process for spot scarfing the surface of a metal workpiece comprising:

• (a) impinging a stream of pilot oxygen gas upon a portion of the workpiece surface which is at least at its oxygen ignition temperature thereby causing a thermochemical rection for providing a pilot puddle of molten metal on the surface of the workpiece;
• (b) causing relative motion between said workpiece and said stream of pilot oxygen gas, so as to continuously produce said pilot puddle of molten metal having a width of about 10 to 30 mm along a chosen path on the surface of the workpiece;
• (c) contacting said pilot puddle with a stream of oxygen gas having a first intensity higher than the intensity of a stream of scarfing oxygen gas so as to spread the puddle to a preselected width of about 100 to 300 mm when said puddle reaches an area to be spot scarfed on said workpiece;
• (d) reducing said first intensity of said stream of oxygen gas of step (c) to a second intensity of up to the intensity of said stream of scarfing oxygen gas upon said puddle being spread to said preselected width;
• and
• (e) scarfing said area by impinging said stream of scarfing oxygen gas on the spread puddle.