Short crack growth and fatigue life in austenitic-ferritic duplex stainless steel

• Published in: Fatigue & fracture of engineering materials & structures Vol. 28; no. 10; pp. 923 - 935
• Main Authors: POLÁK, J., ZEZULKA, P.
• Format: Journal Article
• Language: English
• Published: PO Box 1354, 9600 Garsington Road, Oxford OX4 2XG, UK Blackwell Science Ltd 01-10-2005; Blackwell Science; Wiley Subscription Services, Inc
• Subjects: Applied sciences; crack growth; crack initiation; Cracks; duplex steel; Exact sciences and technology; Fatigue; Ferrites; Kinetics; Materials fatigue; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; plastic strain; short crack; Stainless steel; Fatigue life; Austenitic ferritic steel; Mechanical properties; Fatigue; Plastic deformation; Fatigue crack; Crack propagation; plastic strain; Short crack; crack growth; duplex steel; Duplex stainless steel; Dual phase steel; Crack initiation
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1111/j.1460-2695.2005.00936.x

ABSTRACT
The kinetics of short crack growth has been studied in austenitic‐ferritic 2205 duplex stainless steel. Smooth cylindrical specimens and specimens with shallow notch were subjected to constant plastic strain amplitude loading. The crack growth was studied in notched specimens. The notch area has been mechanically and electrolytically polished to facilitate the observation of crack initiation and growth. The initiated cracks were observed in an SEM (scanning electron microscope). The crack growth was studied using long distance QUESTAR optical microscope equipped with high‐resolution camera. In constant plastic strain amplitude loading the microcracks were initiated and their growth kinetics has been studied. The characteristic features of the crack growth at different plastic strain amplitudes were recorded. Two approaches to analyse the crack growth rates were adopted. The comparison of the prediction of the fatigue life using the plastic‐strain‐dependent crack growth rate was compared with Manson–Coffin law and the relation between parameters of this law and parameters of the short crack growth law were established.