β Scribed by M. Balbi; M. Avalos; A. El Bartali; I. Alvarez-Armas
No coin nor oath required. For personal study only.
The kinetics of microcrack growth during cycling has been studied in a S32205 duplex stainless steel in the as-received and aged (100 h at 475 Β°C) conditions. Cylindrical specimens with a shallow notch were subjected to a constant plastic strain range of 0.3% in both thermal conditions. The characteristic features of surface damage and crack growth showed striking differences in microcrack density, nucleation location and propagation rate between the two thermal conditions even though the fatigue lives are comparable. In the as-received material, microcrack density is low and they nucleate mainly at grain and phase boundaries or second-phase particles. In the aged condition, slip markings first appear in the ferritic phase and they are the preferred site for microcrack nucleation. Crack propagation takes place along slip markings in adjacent grains for crack lengths less than 100 lm. A comparison between fatigue life and the relevant parameters of a microcrack growth law was made.
π SIMILAR VOLUMES
An in vivo investigation of a new high molybdenum and nitrogen duplex stainless steel (25Cr-7Ni-4Mo-00.3N) has been performed. Cylindrical pins and specially developed devices, to test in static conditions the in vivo localized corrosion resistance, made of this new duplex steel and of a common aust
The high-temperature fatigue crack growth (FCG) behavior was investigated for a precipitation-hardening stainless steel, 17-4 PH, in three differently aged conditions. FCG tests were conducted at 400 and 500 Β°C under various load ratios (R-ratios) ranging from R = 0.1 to 0.7. Results indicated the f