High-alloy steels and nickel grades for boiler tubes

摘要

The ever-growing demand for energy calls for an increase in energy-producing capacities. To achieve this, either new power stations have to be built, or the efficiency of existing plants has to be raised to provide the necessary supplies. At the same time, due consideration has to be given to tightened statutory environmental protection requirements and to saving natural resources. This can only be realised by creating the necessary thermodynamic basis, in other words, increasing the process temperature and/or the process pressure in the boiler and the area of the turbine. For this purpose, the process medium - steam - which is produced and brought to the required temperature and pressure in the boiler, must be safely contained on both the boiler and on its way to the turbine. New developments in power station engineering can raise power efficiency to over 50 percent. However, to realise such improvements piping or tubing systems in high-strength materials resistant to corrosion and high-temperature oxidation are indispensable. To meet all related demands, a wide range of high-alloy steels, stainless steels and nickel-base alloys is available for boiler internals and components in the outer boiler environment. To realise the full potential of the material described here in the construction of piping systems, the manufacturing processes currently used must be further developed and optimised both technically and in terms of cost-effectiveness.