Method for manufacturing thin-walled hollow bodies of concentric metal

Abstract

A method for manufacturing thin-walled hollow bodies comprising concentric layers forming thin-walled structural parts of chemical installations subjected to stress at high temperatures, thereby replacing non-layered pipes of single-metal materials. Due to the methods of manufacture, structural parts of these single-metal materials have disadvantages because the single materials of which they are built cannot simultaneously satisfy the demands of corrosion resistance, high-temperature stability and resistance of scaling. According to the new method, for example, thin-walled pipes of concentric, non-corrosive, high-temperature stable, and non-scaling material layers are intended to be produced. For the non-corrosive inner layer, for example, a conventional thin-walled pipe is used. On this pipe high-temperature stable as well as non-scaling layers are produced through build-up welding with one or several welding heads in a manner such that during build-up welding, the thin-walled pipe is filled with a pressurized cooling medium. In build-up welding, the inner pipe is subdivided by partition walls into one or several cooling sections 5 and provided with sectionally functioning cooling circulations adapted to the number of welding heads in the welding regions. The hollow bodies manufactured according to the method are primarily used in high-temperature installations in the chemical industry.