Title

EFFECTS OF DE-STABILIZATION CONDITIONS ON THE PRECIPITATION OF SECONDARY CARBIDE AND MARTENSITE TRANSFORMATION OF HIGH CHROMIUM CAST IRON

EFFECTS OF DE-STABILIZATION CONDITIONS ON THE PRECIPITATION OF SECONDARY CARBIDE AND MARTENSITE TRANSFORMATION OF HIGH CHROMIUM CAST IRON

Authorship

SINATORA, A.; MATSUBARA, Y.

SINATORA, A.

I am this author

MATSUBARA, Y.

I am this author

DOI

10.5151/2594-5327-C00067-997-1011

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Abstract

Hypo- and eutectic chromium white cast irons with about 15%, 20%, 25% and 32% chromium contents were studied to demonstrate de-stabilization heat treatment effects on the subsequent martensite transformation. Employing dilatometer, the start and end points of secondary carbides precipitation curves were obtained. Using the nose temperature for each specimen, the relationship between the volume fraction of precipitated carbides and the holding time were investigated. The volume fraction of precipitated carbides increases as the holding time gets larger and it decreases in number over a certain holding time due to its coarsening, or the diffusion of C and Cr decomposed to eutectic carbides. The behavior of this precipitation presented good correspondence with the change of martensitic transformation temperature (Ms), and it was found that this temperature was proportional to the Cr/C value of the alloy under the same de-stabilization temperature.

Hypo- and eutectic chromium white cast irons with about 15%, 20%, 25% and 32% chromium contents were studied to demonstrate de-stabilization heat treatment effects on the subsequent martensite transformation. Employing dilatometer, the start and end points of secondary carbides precipitation curves were obtained. Using the nose temperature for each specimen, the relationship between the volume fraction of precipitated carbides and the holding time were investigated. The volume fraction of precipitated carbides increases as the holding time gets larger and it decreases in number over a certain holding time due to its coarsening, or the diffusion of C and Cr decomposed to eutectic carbides. The behavior of this precipitation presented good correspondence with the change of martensitic transformation temperature (Ms), and it was found that this temperature was proportional to the Cr/C value of the alloy under the same de-stabilization temperature.

Keywords

White cast iron, destabilization, carbide precipitation

White cast iron, destabilization, carbide precipitation