An estimated 90 percent of all manganese is used in the production of steel. The addition of manganese as an alloying agent to steel makes up about 70 percent of this usage. While most standard steels have a manganese content ranging between 0.15 percent and 0.8 percent, genuine Hadfield grade Tensamang manganese steel plate contains between 11 percent and 14 percent.
Why is all of this added manganese so important? It is because manganese possesses high impact strength and abrasion resistance, thereby enabling manganese steel, otherwise known as mangalloy, to withstand heavy-duty applications like cutting and machining, forming, welding and thermal treatment.
According to the International Manganese Institute, Hadfield manganese steel was named after its 19th century inventor, Sir Robert Abbot Hadfield. A baronet and British metallurgist, Hadfield developed the steel, which “found uses in the construction of railroad rails and rock-crushing machinery” thanks to its “exception durability,” the Encyclopedia Britannica explains. Indeed, steels like Hadfield manganese steel that contain more than 8 percent manganese content have the added benefit of exhibiting tensile strengths of up to 863 MPa.
As it pertains to its history, this steel was the very first alloy steel to ever be invented. The International Manganese Institute goes on to point out that it “has unique properties which make it indispensable for applications in which great toughness and wear resistance are required.” Among the applications cited by the institute are:
- gyratory crushers
- jaw-crusher plates
- railway points
- crossover components
- teeth for earth-moving equipment
- retainer rings for turbo alternators
- collars on oil rigs
Wikipedia adds to this application list the following uses for mangalloy or manganese steel: mining, cement mixers, rock crushers, railway switches and crossings, and crawler treads for tractors, just to name a few.
The addition of manganese to steel results in other benefits as well. First, it allows steel to better respond to quenching because of its impact on the transformation temperature of the metal. Moreover, as the institute explains, “manganese is also a weak carbide former.” In combination, these two manganese properties offer heat treatment advantages for mechanical engineers. In fact, manganese steel is often the metal of choice in bridge construction projects. Finally, but no less importantly, manganese is far more affordable than other steel alloys like nickel. As a result, users can enjoy all the high-impact, abrasion-resistant properties they are seeking at a much lower price point.
Manganese steel is made to withstand even the most severe wear conditions. In fact, it has the unique property of getting stronger (rather than weaker) the more it takes a beating. On the Brinell hardness scale, in fact, the product reaches a hardness score of 550 BHN through work hardening. This rating gives manganese steel almost five times the hardness of mild steel and almost three times the hardness of annealed stainless steel. As such, consumers enjoy a longer lifespan and extended protection of their equipment and facilities. This work hardening property is just another one of the many advantages associated with manganese steel usage.