Microstructural Characterization of a Cobalt-Free Maraging Steel, Vasco Max T-250

摘要

A cobalt-free maraging steel, Vasco Max t-250, is being used as a replacement for the conventional, 18% Ni 300 grade maraging steel used by the Army. The thrust of this programs was to characterized the microstructure of annealed and aged specimens using optical and electron microscopy and X-ray diffraction. The structure of the annealed sample is a heavily dislocated lath martensite. The aged sample are a lath martensite that contains very fine Ni3Ti second phase particles. The precipitates are coherent with the matrix and form in a Widmanstatten pattern. The Ni3Ti precipitates are a very effective strengthening phase of the Vasco Mas T-250 and the aging temperature that appears to optimize the strengthening precipitates is 950 F. Keywords: Maraging steels; Metallurgy; Electron microscopy; Microstructures; Aging (Materials).