Fine-grained high carbide cast iron alloys

Abstract

Embodiments of alloys having high, fine-grained carbide content, and methods of manufacturing such alloys. The alloys can be determined through the use of thermodynamic, microstructural, and compositional criterial in order to create a high strength and high toughness alloy. In some embodiments, the alloys can be used as a wear resistant component.

Description

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS[0001]Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57.BACKGROUND[0002]1. Field[0003]The disclosure relates generally to cast iron alloys used in wear-prone environments and which are resistant to wear.[0004]2. Description of the Related Art[0005]The alloy family known as chromium white irons or chromium white cast irons can refer to alloys containing Fe, C, and Cr which can form eutectic chromium carbides. For example, alloys having chromium levels in the range from 15-30 wt. % (or about 15 to about 30 wt. %) and having carbon levels in the range of 1-3 wt. % (or about 1 to about 3 wt. %) can form such chromium white irons. For chromium white irons, formation of primary chromium carbides is typically avoided which can occur as either Cr or C content is increased. For man...

AI Technical Summary

Benefits of technology

[0008]In some embodiments, computational metallurgy can be used to explore alloy compositional ranges where the total carbide content can be increased without introducing coarse carbide structures known to embrittle the material. When considering the Fe—Cr—C system, the thermodynamic limit for hypoeutectic carbide volume fraction can be 35-40% (or about 35-about 40%). This disclosure describes embodiments of alloys which can meet a set of thermodynamic criteria which can exceed the 40% (or about 40%) carbide content limit, but may not introduce the formation of hypereutectic M7C3, M23C6 or generally any Fe,Cr-rich type carbides. The result is a microstructure which can have a very high level, >40% mole fraction (or > about 40% mole fraction) as defined by thermodynamic models, of fine-grained carbides. As such, this new class of materials can be defined as fine-grained high carbide content cast irons. The utility of such a material can be an increased wear resistance, while maintaining similar levels of toughness to hypoeutectic cast irons.

Problems solved by technology

However, this is done at the expense of toughness.

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