Rietveld quantitative analysis of carbides precipitation in normalized-tempered 2.25Cr-1Mo-0.25V steel

Abstract

The quantitative determination of the mass fractions of precipitates in steels is very difficult using traditional materials characterization techniques. The Rietveld full-pattern fitting algorithm was introduced to solve this problem. The precipitated multicomponents’ mass fraction of M₃C, MC, M₇C₃ and M₂₃C₆ were evaluated precisely and relatively quickly. It is found evolution of carbides apparently occurs during tempering at high temperatures, and a two-step transformation mechanism is proposed for M₇C₃ during early tempering treatment. The method is an effective way on the investigation of precipitation kinetics, which may play a promising role in propertities’ enhancement and design of the heat-resistant steels.

Keywords

2.25Cr-1Mo-0.25V steel / rietveld quantitative analysis / precipitates

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