Stainless Steel Shenanigans

Written By Aidan Chin

Stainless steel seems like a knight in shining armor for metals that seem to last forever in any condition, however it has some secrets up its sleeve that tarnish its reputation (pun intended)

Stainless Steel is a great material for sterile and corrosion vulnerable environments, but to keep that ability, you must follow some seemingly strange rules.

  1. Stainless steel is not always stainless.

    1. When manufacturing with stainless steel there are some things you can do to it to change its properties, when working on stainless steel it is not uncommon to introduce microscopic surface impurities which can remove the stainless from stainless steel. (always use stainless safe brushes and grinders)

    2. There are also time times in welding where moisture and oxygen can get trapped and corrosion can spread from that sort of nucleation site.

    3. Temperature sensitive: lots of stainless steel types are weak to temperature, when too much heat is introduced (500c-800c) the chromium carbide inside of the steel will clump up and compromise corrosion resistance

  2. Funky Magnetism

    1. Special types of stainless steel called austenitic stainless steels are normally non-magnetic despite being made of mostly ferrous metal, but if cold worked (manipulated without heat) or welded, it is possible for them to become magnetic again

  3. Thermal Weirdness

    1. Usually you wouldn’t expect a metal to change so much with temperature change but with stainless many weird things can happen

    2. Through excessive heating, you can weaken the toughness of the metal, making it more brittle

    3. Some types of steel can be work hardened, which means through moving material around without heat, it will become significantly more brittle and hard

As a final fun fact, stainless steel is very useful in kitchens, it loves to be sterile and scientists have even been successful in adding copper to the mix and effectively making antimicrobial stainless steel. finally, there is this fun ability stainless steel has which is scent removal, stainless steel soap is real and really works.

Stainless steel is a very important alloy used in todays world, and we have some in the machine shop here at M5. In order to utilize it fully, we must follow the weird rules of stainless steel.

Aidan Chin
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