Oxygen Cutting

(also gas-torch cutting), a method for cutting metal parts based on the property of metals heated to the ignition temperature of burning in industrial-grade oxygen. Oxygen cutting is performed by preheating the metal to 1200°-1300°C and directing against it a stream of oxygen, which burns through the metal and cuts it apart. The resulting iron oxides flow out in the molten state and are blown out of the region of the cut. The method is used for cutting articles of low- and medium-alloy carbon steels, usually 1 mm to 200–300 mm thick (it is possible to cut steel up to 2 m thick).

Oxygen cutting is performed with a cutter, a special welding torch equipped with an additional device for supplying oxygen. A distinction is made between manual and machine acetylene-oxygen, hydrogen-oxygen, and gasoline-oxygen cutting techniques, depending on the gas used for preheating the metal. Machine cutting with oxygen yields high precision and clean cuts, with high output. Cutting from stencils, special guides, and blueprints, which may be copied on any scale, is done on machines. Several cutters may also be used for simultaneous cutting of several patterns. Oxygen cutting may be automated by using photoelectric devices.

A variety of oxygen cutting is oxygen-flux cutting, which is used for separating metals that are difficult to cut (high-chromium and chromium-nickel steels), as well as for cast iron and alluminum alloys. In this case, the process may be facilitated by blowing powdered fluxes into the cutting area, together with oxygen. In addition to separation oxygen cutting, during which the stream of oxygen is almost perpendicular to the metal surface, oxygen machining is also used. In this case the stream is directed at a slight angle (almost parallel) to the metal surface.

Oxygen cutting is widely used in machine building, shipbuilding, ferrous and nonferrous metallurgy, and construction. Plasma cutting is widely used in industry in addition to oxygen cutting.