Heating is understood to mean a method where the piece being worked is heated by a flame without it smelting or material being lost. Heating methods include flame straightening, flame hardening, heat shaping as well as other types of heating associated with welding, such as pre-heating, point heating and heating and smelting of flame-sprayed surfaces.
- Flame straightening is used for removing deformations that occur in connection with welding, for example.
- In flame hardening the outer level of the material is heated to hardening temperature and then rapidly cooled in order to create hard structures. The method is used in applications where hardness and durability are important, such as the hardening of the bearing holders in axles and the treatment of wear surfaces on rollers.
- Heat shaping is an efficient method for bending plates and profiles. Heat shaping requires a rapid local heating in the same way as flame straightening.
- After welding, it is sometimes necessary to heat the piece being worked in order to eliminate stresses in the material. Flame spraying means that a metal surface is covered with a surface material, often in powder form, which is heated to smelting point. The process provides a strong fusion between the outer cover and the base material. A gas flame is used for heating the material.
When choosing the fuel gas used for heating, many different factors need to be considered – is it, for example, the intention to achieve a rapid and local heating or shall the entire piece to be worked be heated? Rapid and local heating requires a fuel gas providing a hot, concentrated flame with a high heat value. Acetylene is the best alternative. For the even heating of an entire piece being worked you should choose the gas which is most cost-effective with respect to its heat value; consideration should also be given to oxygen consumption, which varies between fuel gases.
By using ODOROX® (odorized oxygen) you can minimize the risk of fire and explosion which are associated with hot work, thanks to the product’s characteristic smell which warns of leaks.
The gas flame is an extremely efficient and versatile aid with regard to heating. Avoid risks by following the safety instructions for hot work.