Effect of notch depth on creep rupture behaviour of 304HCu austenitic stainless steel. (2nd September 2020)

• Record Type: Journal Article
• Authors: Sahoo, Kanhu Charan; Goyal, Sunil; Paul, V. Thomas; Laha, Kinkar
• Is Part Of: Materials at high temperatures. Volume 37:Number 5(2020)
• Page Start: 295
• Page End: 304
• Publication Date: 2020-09-02
• Subjects: 304HCU SS -- multiaxial Creep -- notch depth -- finite element analysis -- SEM characterisation -- EBSD-KAM mapping; Materials at high temperatures -- Periodicals; High temperatures -- Periodicals; 620.1121705
• DOI: 10.1080/09603409.2020.1785084
• Languages: English
• ISSNs: 0960-3409

Abstract

ABSTRACT: Multiaxial creep behaviour of 304HCu austenitic stainless steel was studied at 973 K, 200 MPa by varying depth of U-notches from 1.67 to 3 mm, keeping the root radius of 1.25 mm on cylindrical specimen. Rupture life increased with notch depth and showed a peak value for 2.5 mm depth followed by rapid decrease, indicating the tendency towards notch weakening instead of strengthening. Creep rupture ductility decreased progressively with notch depth, resulting predominantly ductile dimple for shallow depth of notch and creep cavitation induced brittle fracture for deeper notch. Finite element analysis of stress and strain distributions across the notch along with SEM fractography and Electron Backscatter Diffraction (EBSD) studies was carried out to assess the effect of notch depth on creep rupture life. Creep strain concentration through Kernel Average Misorientation (KAM) map also supported the above views of creep strain accumulation which influence creep rupture life of notched specimens.