Selected Metals - 3: 300 Series Stainless Steels
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|Stainless steel was invented by Englishman Harry Brearley in 1913. While attempting to find a more wear resistant steel he alloyed it with a larger than normal quantity of chromium and found the result to be highly resistant to the acid etching pen that he used to mark his specimens (chromium had been used as an alloy in steels for a few years but in only very small quantities). As is often the case with invention, serendipity brings forth something new and unexpected. In this instance a stainless steel was invented while attempting to find a more wear resistant steel..
Over the years many alloys have been mixed into stainless steel however the most common alloying elements are chromium and nickel. Therefore carbon and chromium/nickel percentages give the best profile of this steel.
S300xx (AISI/SAE 300) series are austenitic steels that provide the best corrosion resistance of all the stainless steels. However they will not heat treat like carbon steels and this limits them in strength. 300 series is easy to segregate from other steels because it is non-magnetic.
Following are a few 300 series stainless steels familiar to most machinists (note how carbon, chromium, and nickel effect the properties of the steel).
S30300 (AISI/SAE 303)
S30400 (AISI/SAE 304)
S31600 (AISI/SAE 316)
label: stainles steel, aisa, sae, aluminum, copper, tool steel, history of metal,