Molybdenum in Steel Metallurgy: Building Hardenability, Temper Resistance, Corrosion Resistance, and Creep Strength
Molybdenum is often specified as a percentage on a mill test certificate, yet its commercial value comes from the microstructures it helps create and preserve. In carbon and low-alloy steel, molybdenum can delay transformation, improve hardenability, resist temper softening, and support elevated-temperature strength. In chromium-molybdenum pressure materials, it contributes to creep resistance and process reliability. In stainless steel, it strengthens resistance to localized corrosion in appropriate alloy systems. These functions are not automatic. Carbon, chromium, nickel, nitrogen, boron, section size, austenitising cycle, cooling rate, tempering, welding heat input, and service environment determine whether molybdenum produces the intended result.