The development of alloy steels introduced a variety of new metals, all of which had unique properties, but it was a certain combination of chromium and carbon that led to the discovery of the industry's most superior grade of steel -- stainless. Early experiments that added chromium to steel increased the strength of the metal but contained levels higher or lower than that needed to create stainless. Chromium, at levels of 10-27 percent, in conjunction with a carbon content less than 0.2 percent, created a film on the surface of steel as it reacted with oxygen in the air. This film acts as a protective layer that resists oxidation and heat, giving stainless steel its non-corrosive, rust-resistant qualities.
Pioneers in the alloying of steel each contributed to the development of stainless, but Harry Brearley, a British expert in the analysis of steel, was the first to realize its practical uses. In 1912 Brearley developed a grade of stainless that contained 12.8 percent chromium. He tested certain chemicals against the metal and found it was resistant to corrosion. Brearley quickly realized the benefits of a high-strength, rustless metal and introduced it to the cutlery industry in Sheffield, England. It became the first to mass-produce a stainless steel product.
Stainless steel, with its sleek, shiny surface and tremendous strength, is a marvel of technology. It has revolutionized most modern industries, including food, medicine, and transportation. The non-corrosive and rust-resistant properties of stainless steel have made it essential in the preparation, delivery and storage of food. Stainless steel is a standard in modern restaurant kitchens since it can be easily cleaned and dried. The surface of stainless steel resists oxidation at high temperatures, making the sterilization of medical instruments possible. Its light weight and durability allowed the development of streamlining in transportation. The streamlined design of new trains, planes, and automobiles allowed for less wind resistance, and trains such as the Zephyr helped spark a new design movement. Everything from toasters to vacuum cleaners emulated the new vehicles. Stainless steel paved the way for modern technology and continues to influence our lives every day.