Metal Powder Cutting:

 The metal powder cutting process (POC) is a technique for supplying an OFC torch with a stream of iron-rich powdered material. The powdered material accelerates and propagates the oxidation reaction and also the spalling and melting action of hard-to-cut materials. The powder is directed to the kerf through either the cutting tip or multiple or single jets external to the tip or through the preheated orifice of the tip. When the first method is utilized, gas-conveyed powder is introduced into the kerf by special orifices in the cutting tip. While the powder is introduced externally, the gas conveying the powder imparts adequate velocity to the powder particles to carry them through the preheat envelope into the cutting oxygen stream. In the preheat envelope their short time is sufficient to generated the desired reaction in the cutting zone.

In cutting low carbon steels a pre-heating flame raises the temperature to ignition point. It is the temperature at which oxidation of the iron tale place and iron oxide is formed when a jet of oxygen is blown to the area that is further blown away by the jet resulting in narrow cut. For the sequence to occur, the melting point of the oxide formed should be lower than that of the metal being cut. This is the case in low carbon steel while in the case of non-ferrous metals and stainless steels the oxide formed have a melting point higher than that of the parent metal.

While attempting to cut stainless steel along ordinary oxy-acetylene equipment the chromium combines with oxygen at high temperature and makes a thin coating of oxide with a melting point higher than that of the parent metal. It is hard to remove these oxides, further oxidation does not take place and the cut cannot continue.