Transformation temperature, Crystal structure, Grain structure, Microstructure, Solid-state transformation structures, Quench-age embrittlement, Strain-age embrittlement, Quench cracking, Cast iron, Steel, Hardenability testing, Aluminum alloys, Copper alloys, Nickel alloys, Titanium alloys, Heat treatment, Hardenability, Heat treatability, Hardness, Surface hardness, Phase, Solid, Solid state phase transformation, Annealing, Normalizing, Stress relieving, Surface hardening