In 1882, the English metallurgist Robert Hadfield obtained a new steel grade with a high manganese content (11-14.5% Mn, Fe - 82%, Si - 1%, C - 1%). Its main properties were high wear resistance at high pressures or shock loads, as well as high ductility. Soon, this simple but innovative development found widespread use in industry. Moreover, this brand of steel turned out to be so successful that tracks of tracks of tanks, tractors, cars, armor plates, crusher cheeks, rail crosses, switches operating under shock loads and abrasion, and even window grilles in prisons are still made from it. Well, first things first ...
Soon after the release of Hadfield steel into mass production, the military became interested in it. And by the beginning of the First World War, infantry helmets made of this miracle steel were adopted by the British, and later the American army. Moreover, they were produced practically without changing the technology until the 80s, later replacing the material with a lighter and equally durable organoplastic.
Helped Hadfield steel and tank building. The use of Hadfield steel for the manufacture of tank track links was first mastered by the British company Vickers in the late 1920s. This steel made it possible to significantly increase the resource of tank tracks from 500 km (a record during the First World War) to 4800 km. By the way, in the USSR, the smelting of Hadfield steel was mastered by 1936.
Steel castings are rarely subjected to additional processing, since it is poorly machined by cutting due to surface work hardening during cutting. Therefore, the use of Hadfield steel for the manufacture of bars in prisons was perhaps the most derisive technique against prisoners. Even having a saw for metal, it is impossible to saw through such a grid, since during the cutting process there is a strong work hardening of the treated surface, and as a result - hardening, an increase in hardness to the hardness of the saw cutting it and higher. This factor makes it impossible to saw through the grating made of Hadfield steel.