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Flame processes have a very long history. The original principle is still the same - hydrocarbons are oxidized and thereby generate heat. Flame processes do not require expensive equipment and the energy source is easily carried to the place of use. Most of the processes do not require electricity, cooling water, etc. A torch and a fuel gas cylinder are sufficient for a number of applications, such as welding, heating, brazing, etc., in the electronics or jewelry industries. In the manufacturing industry, demands on the energy content of the flame are somewhat higher and oxygen is added to achieve the required flame temperatures and intensity.
In industrial applications, oxy-fuel cutting is the predominant flame process for cutting of mild and low-alloy steels. Gas welding is a suitable method for welding pipes and plates in thin and medium-thickness steel constructions, cast iron, and to a large extent for hard facing. Soldering and brazing are used to join two metal parts with the help of a filler metal, which has a lower melting point than the parent metal. These parts can be composed of similar or dissimilar metals. Distortions and deformations are straightened by flame straightening, or are added intentionally to generate a special shape. Other flame heating processes include flame spraying, which is widely used for repair work and for coating of parts, for example to improve wear or corrosion resistance or provide a special surface finish. Flame hardening can be used to achieve a partial surface hardening, hot forming to form parts after local heating, and stress relief heat treatment to avoid hardening cracks. Flame gouging is a method that is used to remove materials on the surface, e.g. to repair welding defects, whereas flame cleaning is suitable for removal of surface layers such as rust or paint.
Gas welding, cutting, brazing, etc. - all processes where fuel gases and oxygen are involved can be dangerous if the person using the equipment does not have sufficient knowledge about the equipment and its installation, handling and care. |
