Why is a higher oxygen pressure necessary for cutting than for welding the same thickness of metal?

Why is a higher oxygen pressure necessary for cutting than for welding the same thickness of metal?

• A. Heat the base metal to its kindling point
• B. blow the acetylene into the kerf
• C. Provide enough oxygen to support combustion in the kerf
• D. Burn the metal and blow it out on the kerf

Answer: (D)

Oxy-fuel cutting requires burning away metal in the kerf and pushing the burnt material out as slag. To keep that burning going, you need a strong, high-pressure oxygen jet that reaches into the kerf and sustains the oxidation of the heated metal. The oxygen reacts with iron to form oxides, releasing heat and continuing the cut, while the high-velocity flow blasts the molten oxide out of the kerf so the cut can progress through the thickness. Welding, by contrast, aims to fuse metal without burning it away, so it uses much less oxygen. The choice that states burning the metal and blowing it out on the kerf best describes why higher oxygen pressure is needed for cutting.

Oxy-fuel cutting requires burning away metal in the kerf and pushing the burnt material out as slag. To keep that burning going, you need a strong, high-pressure oxygen jet that reaches into the kerf and sustains the oxidation of the heated metal. The oxygen reacts with iron to form oxides, releasing heat and continuing the cut, while the high-velocity flow blasts the molten oxide out of the kerf so the cut can progress through the thickness. Welding, by contrast, aims to fuse metal without burning it away, so it uses much less oxygen. The choice that states burning the metal and blowing it out on the kerf best describes why higher oxygen pressure is needed for cutting.