Method for producing and assembling superheater tubes of steam generators

A method for producing superheater tubes and connecting pipes and assembling superheater tubes inside a steam generator tube wall, where each of the superheater tubes is formed from straight tubes and bends and each of the connecting pipes includes a sleeve mounted on the outside of the connecting pipe, the method comprising the following steps:

• a) preparing tubes for the straight tubes, tubes for the bends, and tubes for the connecting pipes in a workshop, as well as sleeves consisting of a material that is not to be heat treated, the tubes consisting of precipitation-hardened nickel-based alloys in a solution-annealed state;
• b) manufacturing the bends and the connecting pipes in the workshop using bending tools;
• c) manufacturing the superheater tubes in the workshop by
• connecting the straight tubes and the bends with weld seams, and
• connecting the sleeves with the connecting pipes, in a penetration area of the connecting pipe at the steam generator tube wall, with weld seams;
• d) precipitation hardening the superheater tubes and the connecting pipes having sleeves in the workshop in a first heating device;
• e) connecting the superheater tubes with the connecting pipes on the assembly site inside the steam generator tube walls with a weld seam and connecting the sleeves with a take-up device with a weld seam, the take-up device having been prepared in the steam generator tube walls and being a material that is not to be heat treated;
• and
• f) precipitation hardening the weld seams on the assembly site with second heating devices disposed proximate to the weld seams.