Manganese steel, also called Hadfield steel or mangalloy, is a steel alloy containing 12-14% manganese. Renowned for its high impact strength and resistance to abrasion in its hardened state, the steel is often described as the ultimate work hardening steel.
While all steels and low-alloy steels rust in moist atmospheres, an increase in manganese in steel has a positive effect on corrosion resistance, partly due to the adsorption of manganese ions. Many of mangalloy’s uses are often limited by its difficulty in machining; sometimes described as having “zero machinability.” The metal cannot be softened by annealing and hardens rapidly under cutting and grinding tools, usually requiring special tooling to machine.
The material can be drilled with extreme difficulty using diamond or carbide. Although it can be forged from a yellow heat, it may crumble if hammered when white-hot, and is much tougher than carbon steel when heated. It can be cut with an oxy-acetylene torch, but plasma or laser cutting is the preferred method.
Because of its self hardening properties, manganese steel has been used in the mining industry for many years – cement mixers, rock crushers, crawler treads for tractors, elevator and shovel buckets – as well as in the rail industry (switches and crossings) and other high impact environments.