Big challenge for steel giants

The company has re-engineered its moulds so it can cast ingots weighing close to 300 tonnes which are needed to make the giant steel rolls used in the newest mills, capable of rolling plates up to 4.5 metres or 15 feet 9 inches wide.

But the technical challenge, which had taken two years of research and development to complete, didn't simply involve making bigger moulds.

Forgemasters also had to work out the technical changes it needed to make to the steelmaking, pouring and cooling process to make sure the giant ingots have the same structural integrity as their smaller brothers.

Dr Martin Kearney, technical director of Forgemasters' engineering arm, says there is high demand for the largest rolls because relatively few companies across the globe are able to produce them.

"The new ingot size means we will be producing a finished roll weighing approximately 170 tonnes. To do this, the ingot we work from needs to be closer to 300 tonnes," said Dr Kearney.

"The benefits of these large roll sizes are that the steel sheets they produce are wider. This saves massive amounts of welding time on large-scale constructions, but more importantly, constructions using less welding require less inspection for material fatigue along those joints."

Forgemasters began by increasing the diameter of ingots it could make from 2.7 metres (8ft 10in) to 2.9 metres (9ft 6in). Now it has created moulds for ingots 3.3 metres in diameter, or 10 feet 10 inches – 22 per cent wider than they started out at.

Dr Kearney says Forgemasters worked closely with Siemens VAI – which has operations on Sheffield Business Park - to create an optimum size of ingot for forging the rolls.

It also used the skills of its design and project management subsidiary, Vulcan SFM, to work out the process for making the giant ingots.

Forgemasters, Siemens VAI and another Sheffield firm, DavyMarkham, are at the forefront of designing and manufacturing the world's largest plate mills, which use the giant rolls.