Sir Henry Bessemer was a British inventor born in Charlton in 1813. He invented the Bessemer technique, which was a steel process that included the blowing of air through molten pig iron to remove impurities. This process was a key factor in the success of the Second Industrial Revolution and was used for over 100 years up until 1950.
Bessemer also had over 100 other patented inventions registered to his name. One of them was for the method of casting metal between two contrarotating rollers -the forerunner of the way steel is cast today.
He called it “Twin-Roll Casting” but today the concept has been registered as The Castrip® process.
What is the Castrip® Steel Process?
Instead of traditional slab casting, the Castrip steel process involves depositing molten steel into a catchment space above two contrarotating rollers. These rollers press the steel together at the contact point while cooling it via heat transfer.
What comes out the other side are two sheets of steel still travelling together along the conveyor. These sheets are then cooled, pressed again and sheared to size before being split and coiled onto two separate rolls.
Why Industry Changing?
The Castrip® steel process produces hot rolled steel:
- Faster – Heat transfer between the molten steel making direct contact with the rollers means that solidification takes just 0.15 seconds instead of 18 minutes.
- Thinner – Thinner (more valuable) finished products of less than 1 millimetre can now be produced this way.
- Greener – 80 percent less greenhouse gasses are produced during this steel process.
Mills also save up to 90% of their energy costs and the capital outlay is far less than for a traditional plant. The factory footprint need only be 20 hectares as opposed to 2000 and to break even, the mill need only produce 500 000 tonnes of steel per annum. That’s just 12 percent of current production requirements to turn a profit!
With barriers to entry being so drastically lowered by this steel process, new steel producing start-ups are being formed for the first time in decades and steel consumers can look forward to more competition in the industry and lower prices.
