Powder cutting is an oxygen cutting process where a specific powder is introduced into the oxygen stream to enhance the cutting capabilities.
In essence, powder cutting is an adaptation of standard oxygen cutting, designed to cut materials that are typically difficult or impossible to cut with conventional methods. These materials often include stainless steels, cast irons, and certain non-ferrous metals. The injected powder reacts exothermically (releases heat) with the base metal or acts as a flux, promoting the formation of easily removable oxides.
How Powder Cutting Works
The process involves these key steps:
- Preheating: Similar to standard oxygen cutting, the metal is first preheated to its ignition temperature.
- Powder Injection: A suitable powder, such as iron powder, aluminum powder, or a chemical fluxing agent, is injected into the oxygen stream. This is typically done using a specialized powder feeding system integrated with the cutting torch.
- Oxygen Cutting: The high-pressure oxygen stream, now carrying the powder, is directed at the preheated metal.
- Exothermic Reaction/Fluxing Action: The powder reacts exothermically with the base metal, providing additional heat to sustain the cutting process, or it acts as a flux to remove oxides and other impurities that hinder the cutting action.
- Removal of Molten Material: The oxygen stream also serves to blow away the molten metal and slag, creating the cut.
Benefits of Powder Cutting
- Cuts Difficult Materials: Enables the cutting of stainless steel, cast iron, and other materials that are resistant to standard oxygen cutting.
- Improved Cutting Speed: The additional heat from the powder reaction increases cutting speed.
- Enhanced Cut Quality: The fluxing action can improve the quality of the cut edge.
Examples of Applications
- Demolition: Cutting up large structures made of stainless steel or cast iron.
- Manufacturing: Fabricating components from difficult-to-cut alloys.
- Foundry Work: Removing risers and gates from castings.
Types of Powders Used
The choice of powder depends on the material being cut. Common powders include:
- Iron Powder: Reacts exothermically with the base metal.
- Aluminum Powder: Provides intense heat for cutting.
- Chemical Fluxes: Dissolve oxides and impurities.
