What is a low background steel
12 May 2021, By SteelPrice.Today
"A steel free from nuclear contamination is called Low-Background Steel. The main source of such steel, is ships that sunk before 1945"
Nuclear technology plays major role in cancer detection and treatment. Many modern day scanners with sensors require something called a Low-Background Steel". Many of us are familiar (or at least heard) low Carbon Steel. But what is Low-Background Steel? How it is made? What is its significance?
Nuclear technology plays major role in cancer detection and treatment. Many modern day scanners with sensors require something called a Low-Background Steel". Many of us are familiar (or at least heard) low Carbon Steel. But what is Low-Background Steel? How it is made? What is its significance?
How regular Steel is Made?
Steel is made from Iron. It is stronger and less brittle than the Iron due to its low carbon content.
- Iron ore, which is mined from the ground, contains a lot of impurities and carbon, which act to make the iron weaker.
- To remove these unwanted materials, the Iron is heated up in a blast furnace until it becomes molten.
- Then, limestone is added to the molten iron. The limestone floats on top of the molten iron and draws out the impurities and some of the excess carbon from the iron mixture.
- Air from the atmosphere is used in the process to help remove impurities from the iron ore. These impurities are then drained away, leaving iron with a small, controlled amount of carbon in it, which we call steel.
Nuclear contamination in Atmosphere
In 1945, two nuclear bombs were detonated on Japan during the second world war. along with this, there have been around 1900 atomic weapon testing that released nuclear contamination into the atmosphere.
When this atmospheric air is used during the steel manufacturing, the steel produced is also contaminated. This is something permanent that we have created.
Building highly sensitive scanners and detectors
Scanners with high sensitivity used in patient diagnostics and Geiger counter(radiation detector) cannot use the steel contaminated with radioactive element in atmosphere. Unfortunately, each gram of steel produced after 1945 is contaminated or contain traces of nuclear contamination. The only source to get contamination free steel is, those produced before 1945. And the most reliable source is the sunken ships lying under the sea water.
During the world war 1 and 2 (before nuclear bomb detonation), many war ships were sunken. Steel from these ships are still a treasure that many hunters search for.
Any steel that was made before 1945, which are free from radioactive contamination is called Low-Background Steel.
Even though we have modern technologies to produce steel from iron without any contamination, these processes are highly expensive. Hence steel from sunken ship is cost effective solution. And yes still the equipment made from this source costs millions of dollars.
Not just the medical scanners, even the laboratories that do research on meteorites, moon rocks also require Low Background Steels from sunken ships.