Creep response of austenitic stainless steel foils for advanced recuperator applications

• Main Authors: Osman, Hassan, Tamin, Mohd. Nasir
• Format: Conference or Workshop Item
• Language: English
• Published: 2009
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.utm.my/id/eprint/12621/1/HassanOsman2008_CreepResponseofAusteniticStainlessSteelFoils.pdf; http://eprints.utm.my/id/eprint/12621/

The severe operating conditions of elevated temperature and high pressure of a recuperator foil elements accelera te creep deformation and moisture-induced material degradation. This study is aimed at extending the operating temperature limit of AISI 347 austenitic stainless steel foils in view of maintaining cost competitiveness of the recuperator materials. In this respect, a series of constant load creep-rupture tests are performed on AISI 347 steel foils of thickness 0.25 mm at 700 °c and different load levels. The as-processed (rolled and annealed) foils displayed austenite matrix with transformed carbide precipitates. Results show that the creep life of AISI 347 steel foil samples is dominated by the secondary and tertiary creep stages. The steady-state creep region is characterized by the power-law creep. Phase analysis of creep-ruptured samples indicates the presence of Cr23C6 and NbC along the grain boundaries. Creep cavitations at triple-point grain boundaries are also observed.