Why is Stainless Steel Stainless and What Makes Stainless Steel Stainless???

There are many things in life that I wonder about. Being in the steel industry and selling stainless steel I have at one point in my life asked myself, why do they call it stainless steel? What makes it stainless? It doesn't take much to find out but here is a very brief synopsis of what makes stainless steel stainless so that you can check one more thing off the list in your quest for knowledge.

Harry Brearley Picture from BSSA full article linked below

Stainless Steel might or might not have been invented by a man named Harry Brearley in 1912. Steel has been around for hundreds of years but it hasn't always been stainless. Only after the exact combination of elements had been achieved did we start calling a certain type of steel "stainless". His magic potion contained the keys to what is now called "stainless steel". That being said, the true inventor of stainless is still an ambiguous cloud at best. However, this isn't a discussion on WHO invented stainless but what stainless is and how it's actually stainless. Here is a great article posted by British Stainless Steel Association in regards to the history of stainless as a whole, see here.

So what is in this magic potion that makes a steel not stain or rust? As most of us know if you leave regular steel or metal out in the elements it will rust, oxidize, or stain. Why does stainless not stain? When Harry Brearley Brearley created a steel with 12.8% chromium and 0.24% carbon, that was believed to be the first ever stainless steel. Chromium is the element in stainless that improves the corrosion resistance by forming a chromium oxide film on the steel. This very thin layer, is what allows the steel to be impermeable to rust or staining and when placed under the right conditions, it can also be self-repairing to a certain extent.

There you have it. The answer is Chromium. Chromium is the element when mixed w/other elements in the proper amounts to form the thin layer that protects the steel from rusting, staining or corroding. Hope that helps you in your pursuit of knowledge. 

Michlin Metals is a Woman Owned Small Business, Aerospace Metal and Stainless Steel Distributor. Follow Michlin on Twitter @MichlinMetals, Facebook, LinkedIn, Google+ or on the Web at www.michlinmetals.com. More on the author on Google+.