Microstructure of INCOLOY MA956 after low and high temperature deformation

摘要

NCOLOY alloy MA956 is an Fe20Cr5A10.5Y2O3 alloy produced by the mechanical alloying process which provides a fine dispersion of the yttrium oxide phase in the ferritic Fe-Cr-Al matrix. The alloy, exhibits outstanding strength and corrosion resistance at temperatures even above 1000°C. Calcula-1 tions based on the difference in the elastic moduli of the, oxide particles (dispersoids) and the ferritic. matrix (1, 2) led to the conclusion that the repulsive dislocation-dispersoid interaction can be the source of the strengthening due to Orowanbowing of dislocations between particles. However, after high temperature deformation an. attractive interaction'between dislocations and hard' incoherent oxide particles has been observed, (3, 4);The aim of the present investigations was to revbal the nature of interaction between dispersoids and dislocations developed in INCOLOY MA956 during plastic deformation performed at systematically varied temperatures up to 950 °G. An intention of such investigations was improving our Understanding of the deformation mechanisms in ferritic ODS alloys.