Damage Evolution and Crack Nucleation during High-Cycle Fatigue in Duplex Stainless Steel

MC MARINELLI; U KRUPP; M KÜBBELER; I ALVAREZ; S HEREÑU

Oxford

Encuentro; 8th Meeting of the TC2 on Micromechanisms; 2012

European Structural Integrity Society ESIS

In other to study the damage evolution during High-Cycle Fatigue, stress-controlled cyclic tests were conducted on a standard duplex stainless steel in two different heat treatment conditions (homogenized and embrittled). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) observations in combination with Electron Back-Scattered Diffraction (EBSD) techniques were analyzed. These studies have revealed that the fatigue limit of embrittled samples is substantially larger than the conventional attained at cycles in the homogenized material. A numerical short-crack model to describe quantitatively the propagation behavior of microstructurally short fatigue cracks was proposed and validated with the experimental data.