Today in History – August 13, 1913 – English metallurgist, Harry Brearley cast the first true stainless steel in Sheffield, England. This steel alloy was composed of 0.24% carbon and 12.8% chromium. Brearley (upper left photo) was trying to develop a more erosion-resistant steel for rifle barrels. He etched samples with acid before examining the steel’s grain structure under the microscope. The etching reagents he used were based on nitric acid. He was surprised to find that this new steel strongly resisted chemical attack.
Of course much depends on how true stainless steel is defined. It wasn’t defined as 10.5% chromium until 1911. Prior to this, Stoddard, Farraday and Berthier circa 1820 appear to have discovered that iron-chromium alloys were more resistant to chemical attack. Woods and Clark filed for a patent in 1872 for an acid- and weather-resistant iron composed of 30-35% chromium and 2% tungsten. Brustein in 1875 identified the importance of keeping the carbon content low, but there were no known processing techniques at the time to develop the concept further. Hans Goldschmidt of Germany broke through this barrier in 1895 with the development of the aluminothermic reduction process for producing carbon-free chromium. Researchers that followed documented experiments with low carbon steel and its properties (e.g., Gulliet, Giesen, Monnartz, Borchers).
It is not clear that Brearley built on any of this prior research or not? Was his discovery entirely serendipitous? We may never know. But many others laid claim to the discovery of stainless steel following Brearley’s announcement, including researchers from the U.S., Germany, Poland and Sweden. I like the story of Elwood Haynes (upper right photo) who was motivated to replace his rusty razor with a corrosion resistant version. He, Becket and Dantsizen worked on ferritic stainless steels, containing 14-16% chromium and 0.07-0.15% carbon, in the years 1911-1914. Haynes was awarded a U.S. patent in 1919. Haynes was a graduate of WPI, who makes the claim that Haynes should be credited as the inventor of stainless steel. Haynes had many other inventions, including the metallurgical invention of Stellite that was manufactured by his company, now called Haynes International, located in Kokomo, IN.
Regardless of who you accept as the inventor of stainless steel, there is no question about its impact on modern technology and products. In addition to the stainless razor and cutlery that motivated its development, stainless steel is used for high strength applications in the aerospace, automotive, consumer products, manufacturing, biomedical, chemical, petroleum, construction, railroad and naval industries.
For more information, see the Engineering Pathway’s educational resources on stainless steel or view our Materials Engineering Education, Manufacturing Engineering Education or our Engineering Mechanics Education community sites.