Gas Cutting
Gas or Oxy-fuel cutting is a thermal cutting process which uses oxygen and a fuel gas to cut through various materials.
A mixture of oxygen and the fuel gas preheats the metal to its respective 'ignition' temperature, but still below its melting point. A jet stream of pure oxygen is passed into the preheated area causing an intense chemical reaction between the oxygen and the metal to form iron oxide or slag along with the generation of heat. The jet blows away the slag, with the help of oxygen, enabling the jet to pierce and cut through the material.
Important factors involved in gas cutting:
- Oxygen dilution should be as minimal as possible, as it can impact the performance of the cutting process.
- The temperature of the metal piece must be below its melting point for the cutting process to be successful.
- The oxidation reaction between the metal and oxygen gas must be high enough so that the ignition temperature remains constant.
- The melting point of the oxide which is formed must be lower than the current temperature of the metal, otherwise the slag cannot be blown or wiped away by the jet stream of oxygen.
Common Gas types used in Gas cutting:
- Natural gas
- MAPP
- Acetylene
- Propylene
- Propane.