Creep properties and microstructural evolution of austenitic TEMPALOY steels

S. Caminada (a),*, G. Cumino (a), L. Cipolla (b), D. Venditti (b), A. Di Gianfrancesco (b), Y. Minami c, T. Ono (c)

(a) TenarisDalmine, Piazza Caduti 6 Luglio 1944 1, 24044 Dalmine (BG), Italy
(b) Centro Sviluppo Materiali SpA, Via di Castel Romano 100, 00128 Rome, Italy
(c) Tenaris NKKTubes, 1-10 Minamiwatarida, Kawasaki, 210-0855 Kanagawa,Japan

International Journal of Pressure Vessels and Piping

doi:10.1016/j.ijpvp.2010.03.009

Abstract

The steam parameters in the new high efficiency fossil fuel power plants are continuously increasing, requiring new advanced materials with enhanced creep strength able to operate on the most severe temperature and pressure conditions. For super-heater and re-heater applications, TEMPALOY AA-1 steel, an evolution of 18Cr10NiNbTi alloy, has been developed through the addition of 3%Cu and B, significantlyenhancing the creep resistance, while offering typical corrosion properties of 18%Cr steels. This paper describes Tenaris’ tubular products in the field of austenitic grades for applications in Ultra Super Critical power plants: the production route and the main microstructural and mechanical properties of TEMPALOY AA-1 and TEMPALOY A-3 steels, including the effect of shot blasting on steam-oxidation resistance, their creeperupture properties and their microstructural evolution during temperatureexposure are presented.

For more info please contact: l.cipolla@c-s-m.it