Anomalous kinetics of lath martensite formation in stainless steel. (August 2015)

• Record Type: Journal Article
• Authors: Villa, M.; Hansen, M. F.; Pantleon, K.; Somers, M. A. J.
• Is Part Of: Materials science and technology. Volume 31:Number 11(2015:Nov.)
• Page Start: 1355
• Page End: 1361
• Publication Date: 2015-08
• Subjects: Phase transformation kinetics, -- Martensitic phase transformation, -- Stainless steel, -- Magnetometry; Materials science -- Periodicals; Microstructure -- Periodicals; Metallurgy -- Periodicals; 620.1105
• DOI: 10.1179/1743284714Y.0000000709
• Languages: English
• ISSNs: 0267-0836

Abstract

Abstract : The kinetics of lath martensite formation in Fe–17·3 wt-%Cr–7·1 wt-%Ni–1·1 wt-%Al–0·08 wt-%C stainless steel was investigated with magnetometry and microscopy. Lath martensite forms during cooling, heating and isothermally. For the first time, it is shown by magnetometry during extremely slow isochronal cooling that transformation rate maxima occur, which are interrupted by virtually transformation free temperature regions. Microscopy confirms martensite formation after athermal nucleation of clusters followed by their time dependent growth. The observations are interpreted in terms of time dependent autocatalytic lath martensite formation followed by mechanical stabilisation of austenite during the transformation process.