Resumen

MESA GRAJALES, Dairo Hernán; GARZON OSPINA, Carlos Mario  y  TSCHIPTSCHIN, André Paulo. ASSESSMENT OF CAVITATION-EROSION WEAR OF A HIGH NITROGEN AUSTENITIC STAINLESS STEEL FROM ELECTRON BACKSCATTERING DIFFRACTION-EBSD. Ingeniare. Rev. chil. ing. [online]. 2010, vol.18, n.2, pp. 235-243. ISSN 0718-3305.  http://dx.doi.org/10.4067/S0718-33052010000200010.

Stainless steel samples with 100% austenitic microstructure and alloyed with 0.9 wt-% of nitrogen in solid solution were tested under vibratory cavitation experiments in distilled water to study the cavitation-erosion wear (EC) at grain size level (mesoscale). Fully austenitic samples were obtained by high temperature gas nitriding (HTGN) a commercially available dúplex stainless steel, UNS S31803. The samples were characterized by electron backscattering diffraction, EBSD to obtain the crystalline orientation of individual grains. In addition, mass loss measurements were obtained and surface damage evolution was analyzed by scanning electron microscopy (SEM) at different times of the test. These results were analyzed as a function of the prior crystallographic characterization. For comparison, a conventional austenitic stainless steel, UNS S30403, was also investigated. It was observed that both the nucleation and the growth of damage are heterogeneous at the grain-size scale due to mesoscale plasticity anisotropy, induced during the CE tests. The heterogeneous character of the cavitation damage is related to both the grain boundary character and the microtexture inside the grains.

Palabras llave : High nitrogen stainless steels; cavitation erosion wear; electron backscattering diffraction - EBSD; meso-texture.