Molybdenum and iron composed of iron alloys, generally containing 50 to 60% molybdenum, used as alloy additives for steelmaking. Ferro molybdenum is an alloy of molybdenum and iron. Its main use is as an additive of molybdenum in steelmaking. Adding molybdenum to the steel can make the steel have a uniform fine crystal structure, and improve the hardenability of the steel, which is conducive to eliminating temper brittleness. Molybdenum can replace part of tungsten in high speed steel. Molybdenum, combined with other alloying elements, is widely used in the production of stainless steel, heat-resistant steel, acid-resistant steel and tool steel, as well as alloys with special physical properties. Molybdenum added to cast iron can increase its strength and wear resistance.
Molybdenum has an atomic weight of 95.94. The outer electronic structure is 4d5s, the melting point is 2615℃, the boiling point is 4610℃, and the density (20℃) is 10.2g/cm. The binary phase diagram of molybdenum and iron is shown in Figure 1. Molybdenum and iron form two solid solutions α and γ and two intermetallic compounds ε(Fe7Mo6) and σ(FeMo) phases. Industrial ferro molybdenum contains about 60%Mo, melting temperature is 1800 ~ 1900℃; The density is about 9.0g/cm.
The role of molybdenum in steel can be summarized as improving hardenability, improving thermal strength, preventing tempering brittleness, improving remanence and coercivity and corrosion resistance in some media, and preventing pitting tendency. Due to the various beneficial effects of molybdenum in steel, it has been widely used in a series of steel grades such as structural steel, spring steel, bearing steel, tool steel, stainless acid-resistant steel, heat-resistant steel (also known as heat-strong steel), magnetic steel. Molybdenum in cast iron is very effective in improving strength and toughness, when the amount of 0.25% to 1.25%, the casting of medium and large section can also form pearlite matrix structure. Commonly used in rolls and other wear resistant castings.
Post time: Jan-26-2024