Aging-Induced Transformations of Maraging-400 Alloys

• DOI: 10.1007/s11661-018-4724-y
• Publication Date: 2018-06-04T18:06:25Z
• Authors: T. J. B. Alves; G. C. S. Nunes; L. F. S. Tupan; P. W. C. Sarvezuk; F. F. Ivashita; C. A. S. de Oliveira; A. Paesano
• Keywords: Maraging steel; Tetragonal crystal system; Rietveld Refinement

Solubilized maraging-400 alloys were aged at 480 °C, 580 °C, and 650 °C, for 3, 6, and 12 hours and characterized by X-ray diffraction (Rietveld refinement), Mossbauer spectroscopy, and microhardness tests. The results revealed that the aging treatments induced an atomic rearrangement in the martensite phase, involving a change in the composition and lattice parameters, reversion of austenite, and, in some samples, the formation of the μ phase. The amounts of reverted and precipitated phases were dependent on the aging time and temperature. The tetragonal distortion from cubic symmetry, usually presented by martensite in solution-annealed maraging steels, was not eliminated after aging. The results obtained for these maraging-400 alloys are compared with those obtained for maraging-350 steel samples.