Sheffield Forgemasters International Ltd. reports recently it processed the largest ingots ever to be forged from a specialty grade of stainless steel. The ingots were produced in an electroslag remelting (ESR) process by Rubiera Special Steel SpA, a part of the Ringmill Group.
ESR is a process for remelting and refining steel and “superalloys” for critical materials used in aerospace, defense, and power-generation systems.
Large-dimension parts are more than a specialty for Sheffield Forgemasters: they are a way of life. SFIL produces steel castings up to 350 metric tons and forgings of up to 275 mt. It claims to have supplied more than 46,000 mt of engineered components to the offshore oil-and-gas industry.
> Another large-dimension program lately in the news for SFIL involved a series of forged steel rolls for the Magnitogorsk Iron and Steel Works in Russia, a Severstal operation that processes automotive quality hot- and cold-rolled steel.
> Last fall, SFIL produced a series of oversized castings under contract to SMS Meer, which placed an order for 11 castings to be supplied over two years, for mill stands it is manufacturing, a project reported to be worth $19 million, according to SFIL.
> Even more recently, SFIL began pouring a series of ingots that required 600 metric tons of molten steel and will weigh over 320 metric tons in their finished state.
“This is not the first time we have produced castings of this size, but the process is highly complex with precise timescales for each element of the pour – from melting the steel, transporting such large volumes of molten steel across the site and scheduling the continuous pour,” explained SFIL’s Dr. Steve Price, managing director of sales. “I am pleased to say that the process went exactly as planned and we are already scheduling the second casting in over the next four weeks.”
In the stainless steel forging project, Forgemasters worked with the Italian manufacturer to develop the finished products, which are destined to operate in high-stress conditions (as required in petrochemical refining) as components of a pressure-vessel system for a global chemicals manufacturer.
SFIL’s role is forging and rough-machining the ingots, each weighing over 170 metric tons, as well as finish machining and pressure testing the completed assemblies.
“For such a safety-critical application we needed a partner who could manage product development alongside a production commitment,” according to David Bunney, sales manager at SFIL. “Rubiera worked extremely hard to demonstrate their capabilities for making 15-5PH stainless steel of the highest quality and to meet exacting client expectations.”
Bunney, who also chairs the U.K. Pressure Vessel Manufacturing Forum, added: “Pressure vessel manufacture has a long history at Forgemasters, with many large-scale units produced over many years. We see considerable potential in the global market in the coming years for pressure vessel equipment.
“One of Forgemasters’ strongest, unique selling points is the time-served reliability of our products,” he continued, “which gives clients the confidence to work with us where safe operation is the prime consideration.
“This is a significant order as it demonstrates this company’s expertise in capitalizing on a diverse range of markets through the provision of proven technical manufacture,” he concluded.