karkaisevuus
Karkaisevuus is a term used in metallurgy to describe the hardenability of a material, especially steel. It denotes the propensity of a steel alloy to develop martensitic hardness deeper than the surface when subjected to heat treatment. The word stems from the Finnish verb karkaistaa, meaning to harden, with the abstract-noun suffix -vuus. In practice, karkaisevuus characterizes how far into a cross-section a given cooling rate will produce a hardened structure, rather than the surface hardness alone.
Measurement and interpretation: Hardenability is commonly assessed with the Jominy end-quench test, which yields a hardness-versus-distance
Applications and limitations: Hardenability informs steel selection and heat-treatment design for components where deep hardness is