WWI and the growth of Stainless Steel
September 15, 2014
There’s a keystone in every great invention.
Stainless steel is used in a wide variety of applications due to its superior resistance to stains, rust, and corrosion. Metallurgists began investigating its benefits as early as the 1800s, but stainless steel didn’t truly rise to prominence until World War I.
Set against the escalating arms race between the colonial powers of Europe, stainless steel was in its early development stages in 1912. The British military sought a more viable metal for firearms; soon a small arms manufacturer commissioned England-based firm Thomas Firth & Sons to create the stronger steel material needed.
Several metals were prone to erosion due to the heat and friction produced from a gun’s discharge, leading Harry Brearley, the head of Thomas Firth & Sons at the time, to begin experimenting with a steel alloy using higher levels of chromium and lower levels of carbon.
Some of Brearley’s experiments led him to discard many samples; he later discovered that his discarded samples were rust-free, even after a long period of time. Further experimentation led Brearley to discover how to make the steel resistant to certain chemicals, like acid.
Stainless steel didn’t end up being used in firearms, but it was used for aircraft components, such as exhaust valves and engines. The material was a natural choice for aviation applications due to its ability to withstand extremely high temperatures.
After the war, the development of stainless steel continued to grow exponentially. Metallurgists experimented with different formulas to create various types of stainless steel, but there are three types used: austenitic, ferritic, and martensitic.
· Austenite is the primary phase of austenitic steel. These alloys contain chromium (18%) and nickel (8%) and can occasionally contain manganese and nitrogen elements. Austenitic alloys can’t be hardened by heat treatment, and the most notable stainless steel series is Type 304, also known as surgical stainless steel.
· Ferritic steels utilize ferrite as their main phase. These steel alloys contain iron and chromium (17%) and is less ductile than austenitic steel; ferritic steel also can’t be hardened by heat treatment.
· Martensitic steel alloys have a composition of iron, chromium (12%), and carbon (0.12%). The composition of these alloys allows them to be tempered and hardened for additional hardness. Martensitic alloys offer superior hardness, but it also reduces the integrity of the material, making it less resilient.
Though stainless steel was originally meant to strengthen firearms, the material became even more popular during the war when used to enhance cutlery and medical instruments such as scalpels, forceps, and other tools.