Specialty Metals and Minerals: Flash Bainite – a New Steel
A new steel, developed by Gary Cola a few years back, is now being tested by three of the world’s largest car makers. What is quite amazing is that Gary is a self-taught metallurgist and he produced the steel from his own laboratory in Detroit.
Flash Bainite has some amazing properties. It is stronger than titanium by weight and very ductile. It can be formed while cold without cracking or deforming in any way. This leads to much lower manufacturing costs and much less steel for the same strength as conventional steels. It has already been tested by the US Army who concluded that “Flash Bainite demonstrated an impressive combination of strength, elongation, ductility, and toughness.”.
If accepted by the car industry it will lead to cheaper, lighter cars with less steel and energy being used in the manufacturing process. A win all around, except perhaps for the iron ore industry. So much for steel being a “mature” industry.
I will briefly describe the difference between Flash Bainite and other steels below. Be warned that it is somewhat dry.
First, the difference between iron and steel. Iron is the element whereas steel is an alloy with up to 2% carbon and possibly other metals, such as molybdenum and chromium. The iron in steel can crystallise in a variety of structures, depending upon factors such as the temperature it is heated to and the rate at which it is quenched.
In general, the trade off in steel is between strength and ductility. For example, a martensitic crystalline structure results in hard, strong, but brittle steel. It forms when steel is rapidly quenched, from around 750oC to 450oC in less than a second. Other crystal forms of iron in steel include austenite, bainite and perlite.
Flash Bainite is unique in that it is both strong and ductile. It is formed by taking standard carbon steel and rapidly heating it by flame/induction to around 1,000oC. After about two seconds the steel is water quenched at a very high cooling rate of up to 3,000oC/second. The result is a combination of martensite and bainite ordered in a specific way.
This revolutionary new steel looks set to transform industry. It can be produced on a small scale at low cost. Gary Cola is also suggesting that he will licence the process which could see it in very widespread use. In addition to its potential pressure on the iron ore industry, in some applications it will compete with aluminium.