Introduction to the beginning of stainless steel

The secret to the success of stainless steel lies in its incredible physical and chemical properties. Stainless steel has high corrosion resistance, heat resistance , formability and weldability, durability, and does not rust. On top of this, the metal does not readily react to many substances, and is inexpensive compared to specialist, non-corrosive alloys. Over the past century, metallurgists have invented and improved methods to make stainless steels, control their properties, and mass-produce them with consistent quality.The year 2013 marks the centenary of the invention of this remarkable metal, and in this article we take a brief look at the history of one of the most important breakthroughs in materials science.

In 1913, Harry Brearley of Sheffield, UK discovered ‘rustless’ steel. Although there had been many prior attempts, Brearley has been credited with inventing the first true stainless steel, which had a 12.8% chromium content. He had added chromium to molten iron to produce a metal that did not rust. Chromium is a key ingredient, as it provides the resistance to corrosion. After this discovery, Sheffield itself became synonymous with steel and metallurgy.Over the last 100 years, about 100 grades of stainless steel have been discovered and made commercially available. These grades fall under four main family groups, namely, martenistic, ferritic, austentic, and duplex.

Ferritic and martensitic stainless steels are magnetic while austenitic stainless steels are non-magnetic. These have varying quantities of other alloying metals like nickel, titanium, and copper, added to them. Carbon and nitrogen are also added to enhance the overall characteristics of stainless steel. China is the largest producer of stainless steel in the world. One of the leading stainless steel producers and distributors is Outokumpu, a group of companies headquartered in Espoo, Finland.Stainless steel has found a myriad of applications from the tiniest structural parts in artificial heart valves to the largest architectural structures. Several world famous monuments, such as the Cloud Gate sculpture in Chicago, have been constructed using stainless steel.With the growing awareness about the importance of reducing carbon emissions, many countries are keen on promoting stainless steel which is resistant to corrosion and has prolonged service life, therefore not requiring frequent replacements and repairs.

Additionally, stainless steel is also 100% recyclable and does not degrade when reprocessed, thus allowing for multiple life cycles. The sustainability of stainless steel is unmatched compared to other metals.Brearley stumbled upon this discovery whilt trying to solve the problem of erosion of the internal surfaces of gun barrels for the British army during the onset of the First World War.After the initial discovery, further improvements to stainless steel occurred at a fairly rapid pace. In 1919, Elwood Haynes obtained a patent on martensitic stainless steel, in 1929 William J. Kroll of Luxembourg was the first to discover precipitation-hardening stainless steel, and in 1930 duplex stainless steel was first produced in Sweden at the Avesta Ironworks.The outstanding properties of stainless steel were gradually realized over the years, and below is a short timeline outlining some of the key moments in the history of stainless steel.