| Steam parameters of power stations pass through middletemperature(MT)- middle pressure(MT), high temperature( H T )-highpressure(HT), sub-critical, super-critical and ultra-super-critical stages. Steampressure and steam temperature increase constantly in order to improve the efficiencyof the unit. Due to a short history of steel industry in our country, some of the materialbehaviors and heat treatment technique are still located in a lower level. In recent yearssome developed countries, such as, Japan, U.S.A., Germany, have developed new-typerefractory steels and have had a lot of experience of welding heat treatment in metal. Inthis paper the welding heat treatment technique for the main structural steel used inpower plant has been analyzed and studied. Some results has been applied in practice. The improvement of steel behaviors has met the need of increasing steamtemperature and pressure. But the welding technology and its heat treatment techniquebecome a key factor for maintenance of components and construction of power plant.The paper discusses the welding technique for the typical steel and the technology fordifferent kind of steel welding. |
