October 21, 2026 · Indumor
Alloy steel: steel to which, besides iron and carbon, other elements are deliberately added — manganese, chromium, nickel, molybdenum, tungsten, vanadium — in amounts large enough to change its properties. The European standard EN 10020 defines it by thresholds: 0.30% chromium or nickel is enough, for example, or 1.65% manganese. The definition is exact, and it misses the best part: behind every element there is someone who tried adding something more to iron to see what happened.
The story fits in one paragraph. Between 1819 and 1824, Michael Faraday and the cutler James Stodart tried alloys with silver, platinum, rhodium, chromium and nickel in London. In 1856, Robert Mushet used manganese to cure the defect that made Bessemer's cheap steel crack in the rolling mill, and in 1868 he used tungsten to create the first commercial self-hardening tool steel. In 1882, Robert Hadfield found manganese steel, which hardens under impact. By the end of that decade, nickel had reached armor plate. In 1900, Taylor and White showed tools cutting red-hot in Paris. And between 1912 and 1913, in Essen and in Sheffield, stainless steel was born.
In 1819, Faraday analyzed wootz, the crucible steel of India. With Stodart, a maker of knives and surgical instruments, he tried to imitate it and then tried silver, platinum, rhodium, gold, copper, chromium and nickel. They rated rhodium steel the best; they dropped nickel because it rusted more. The metals that worked were very expensive, and no industry came of it. What remained were the samples, still kept at the Science Museum in London, and an idea: steel could be designed. In 1821, in France, Pierre Berthier saw that high-chromium alloys resisted acids that ate iron, although they were so brittle they could be ground to powder.
In August 1856, Henry Bessemer announced his converter: by blowing air through molten pig iron, he made steel in minutes. But the metal came out over-oxidized and cracked when it was rolled. That September, Robert Mushet, a metallurgist from the Forest of Dean, patented the fix: add spiegeleisen, an alloy of iron, manganese and carbon, at the end. Manganese takes out the oxygen and offsets the sulfur; the carbon brings the steel back to its target. In 1859 his patents lapsed over an unpaid fee, and Mushet was left out in the cold; from 1866, Bessemer paid him £300 a year.
In 1868 he introduced R. Mushet's Special Steel, with tungsten, manganese and plenty of carbon; the recipe was always kept secret. It hardened by itself, cooling in air, without the water quench that cracked parts, and it kept its hardness even when cutting heated it. Samuel Osborn & Co. of Sheffield made it under exclusive rights, and lathes could run faster.
In 1882, in Sheffield, a young Robert Hadfield tried a proportion nobody expected to work: 12 to 14% manganese, with 1 to 1.4% carbon. Water-quenched from a high temperature, it came out tough, the opposite of carbon steel; it was practically non-magnetic and, when struck, its surface hardened. He patented it in 1883, and it ended up in railway crossings, crusher jaws and excavator teeth.
Watch out: manganese steel is not treated like ordinary steel. Overheated without control, it loses the toughness that made it famous, which is why it is welded with short beads, special filler metals and the part kept below about 260 °C (500 °F).
Nickel came back through armor plate. Around 1888 and 1889, the French firm Schneider added it to its plates. In September 1890, at Annapolis, Schneider's nickel plate beat the plain-steel ones. At the 1900 Paris Exposition, Bethlehem Steel showed tools cutting with their tips glowing red. Frederick Taylor and Maunsel White had not invented an alloy: they had found that chromium-tungsten steels, heated almost to melting before quenching, kept their hardness when hot. According to their patents, they cut 1.5 to 2.5 times faster. It was the beginning of high-speed steel.
In October 1912, Benno Strauss and Eduard Maurer filed patents at Krupp for two chromium steels, one of them austenitic with nickel: V2A, later sold as Nirosta. In Sheffield, Harry Brearley was looking for a steel that would resist erosion in rifle barrels, and in August 1913 he cast one with 12.8% chromium and 0.24% carbon. When he tried to etch it with nitric acid, the acid barely touched it, and vinegar and lemon juice did not stain it. Sources disagree on the day: some say August 13, others August 20. Brearley called it rustless steel; the name stainless was suggested by Ernest Stuart, of the R. F. Mosley cutlery works.
Today the boundary is a table: EN 10088 requires at least 10.5% chromium for a steel to be called stainless. Type 304, with about 18% chromium and 8% nickel, is a direct descendant of that Krupp steel; 316 adds 2 to 3% molybdenum. And in any shop, alloy steel is everywhere: in the wear plate of a hopper, the manganese of a crusher, the stainless of a food tank and the drill bits that make the holes.
If a shutdown is coming at your plant and hoppers or chutes are already due for new liners, now is the time to survey them: the parts get made before the shutdown, not during it. We can help with the chutes and their liners from Indumor.
Sources: Philosophical Transactions (1822), Annales des Mines (1821), Grace's Guide, Science Museum Group, US patents 668,269 and 1,197,256, World Stainless Association and Historical Metallurgy Society.
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