A cutting torch (also flame cutting device , torches or colloquially hose or Feuersäge is called) a tool for torch cutting of metals and other substances. The corresponding machine tool is a flame cutting machine .
The material to be cut is heated to its ignition temperature (usually over 1000 ° C) with a heating flame - similar to that of a welding torch . By switching on the cutting oxygen , which is blown through the heating flame under pressure, the material is burned and the slag is blown out at the flame outlet. An acetylene or propane - oxygen mixture is used for the heating flame .
The ignition temperature of the metals to be cut must not be too high and the resulting oxides must be liquid at the working temperature. This essentially only applies to unalloyed and low-alloy steels. Steels with a minimum tensile strength of 800 N / mm² must be preheated, otherwise a hard and brittle molecular structure ( martensite ) is created on the cut surfaces and in the heat-affected zone . Gray cast iron cannot be cut because of its high carbon content and the resulting low melting point.
The advantage of the process lies in the possibility of processing large material thicknesses (up to 300 mm, in special designs up to 1000 mm) at a high feed rate with a relatively small and light tool. For manual cutting, the parts to be machined generally do not have to be clamped on devices. The risk of fire , changes in the material at the cut edges and, above all, the state of tension of the components to be cut limit the application.
Areas of application
Hand cutting torches are used in workshops or on construction sites, and in Germany they are also part of the equipment used by technical relief organizations and the fire brigade . Machine cutting torches are part of oxy-fuel cutting machines .
- Jörn Lütjens: About the flame cutting suitability of iron-carbon materials ( Memento from April 1, 2010 in the Internet Archive ) (PDF; 9.6 MB).