3D Printing Metal Powder

Tungsten Carbide and Corrosion Resistance

2023-03-13 07:40:03  News

Tungsten carbide is one of the most corrosive resistant alloys available and Reparex offers standard and custom tungsten carbide grades for use in both high toughness and corrosion resistance applications. TufCote, for example, is a cast tungsten carbide granule in a nickel matrix that can be applied to your equipment and is highly resistant to both wear and corrosion.

Tough and strong by nature, tungsten carbide offers excellent resistance to impact and wear with a shear modulus of over 80 GPa - more than double that of steel. This property makes tungsten carbide a top choice in extreme wear and impact applications where its cladding, casting and welding properties simply last where others fail.

The brittle molecular structure of tungsten is what allows it to retain its strength through temperature changes. This unique characteristic also helps explain why tungsten and tungsten carbide are such great candidates for compressive strength: they have lower tensile strengths than their ductile counterparts but they are much stronger in compression.

WC & W-Cr-C coated tungsten showed a large difference in the corrosion rate when compared to bare tungsten under the same conditions, with the cladding causing a reduction of intergranular corrosion (due to impurities segregated at the grain boundaries) to pitting corrosion (where holes form and spread). This change in corrosion type was attributed to the increased number of microcorrosion cells after both the Cu-free and Cu-added alloy systems were water quenched.

The difference in the corrosion rate induced by the different surface treatments could be attributed to the formation of secondary carbide particles during water quenching, resulting in enhanced diffusion of secondary carbides and microcorrosion cells within the martensitic matrix. These enriched secondary carbides could serve as preferential sites for localized corrosion attacks that rely on the diffusion of carbon, which may lead to higher levels of abrasion and wear than those present on bare tungsten.