Duplex stainless steels (DSS) fatigue crack propagation resistance is strongly affected by both microstructure and environment. In this work, environment influence on the fatigue crack propagation in a 22 Cr 5 Ni duplex and in a 25 Cr 7 Ni superduplex stainless steels is investigated considering three different stress ratios (R = Kmin/Kmax = 0.1, 0.5, 0.75). Tests are performed according to ASTM E 647 standard, both in air and under hydrogen charging conditions (0.1 M H2SO4 + 0.01 M KSCN aqueous solution, -0.9 V/SCE). Crack fracture surfaces are extensively analysed by means of a scanning electron microscope. Furthermore, crack paths are investigated by means of a crack profile analysis performed through a light optical microscope. Nickel coated fracture surface sections obtained for constant ΔK values are considered in order to analyse the loading (R values) and environment influence on fatigue crack paths. © 2007 Elsevier Ltd. All rights reserved.
22 Cr 5 Ni duplex and 25 Cr 7 Ni superduplex stainless steel: Hydrogen influence on fatigue crack propagation resistance / Natali, Stefano; V., Di Cocco; E., Franzese; F., Iacoviello. - In: ENGINEERING FRACTURE MECHANICS. - ISSN 0013-7944. - 75:3-4(2008), pp. 705-714. [10.1016/j.engfracmech.2007.01.008]
22 Cr 5 Ni duplex and 25 Cr 7 Ni superduplex stainless steel: Hydrogen influence on fatigue crack propagation resistance
NATALI, Stefano;
2008
Abstract
Duplex stainless steels (DSS) fatigue crack propagation resistance is strongly affected by both microstructure and environment. In this work, environment influence on the fatigue crack propagation in a 22 Cr 5 Ni duplex and in a 25 Cr 7 Ni superduplex stainless steels is investigated considering three different stress ratios (R = Kmin/Kmax = 0.1, 0.5, 0.75). Tests are performed according to ASTM E 647 standard, both in air and under hydrogen charging conditions (0.1 M H2SO4 + 0.01 M KSCN aqueous solution, -0.9 V/SCE). Crack fracture surfaces are extensively analysed by means of a scanning electron microscope. Furthermore, crack paths are investigated by means of a crack profile analysis performed through a light optical microscope. Nickel coated fracture surface sections obtained for constant ΔK values are considered in order to analyse the loading (R values) and environment influence on fatigue crack paths. © 2007 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
