Tweco 30 O2 Auto-Cut - Manuel (Page 79)

Manual No. 0-4818 Auto-Cut 300
2
4-11 OPERATION
3. Oxygen (O
2
) Plasma
• Oxygen is recommended for cutting ferrous materials.
• Provides faster cutting speeds.
• Provides very smooth finishes and minimizes nitride buildup on cut surface (nitride buildup can cause
difficulties in producing high quality welds if not removed).
4. Nitrogen (N
2
) Plasma
• Provides better cut quality on nonferrous materials such as stainless steel and aluminum.
• Can be used in place of air plasma with air shield.
• A good clean welding grade nitrogen should be used.
B. Shield Gases
1. Compressed Air Shield
• Air shield is normally used when operating with air or oxygen plasma.
• Improves cut quality on some ferrous materials.
• Inexpensive - reduces operating costs.
2. Nitrogen (N
2
) Shield
• Nitrogen shield is used with nitrogen (N
2
) or Ar/H
2
(H35) plasma.
• Provides smooth finishes on nonferrous materials.
• May reduce smoke when used with Ar/H
2
plasma.
3. Water Shield
• Normally used with nitrogen.
• Provides very smooth cut surface.
• Reduces smoke and heat input to the workpiece.
• Effective up to 1/2 inch (12.7 mm) maximum material thickness.
• Tap water provides low operating expense.