Liberty Speciality Steels Accelerates Production of Ultra-Clean Speciality Steels with New Vacuum Induction Melting Furnace

Liberty Speciality Steels accelerates production of ultra-clean speciality steels with new vacuum induction melting furnace

Reprint from „MPT International“ (2017), issue-no. 4, page 48 – 53. LIBERTY SPECIALITY STEELS

Liberty Speciality Steels, Stocksbridge, Sheffield, UK Contact: www.libertyspecialitysteels.com E-mail: [email protected]

SMS group, Düsseldorf, Germany Contact: www.sms-group.com E-mail: [email protected]

2 Liberty Speciality Steels accelerates production of ultra-clean speciality steels with new vacuum induction melting furnace

At its Stocksbridge, Sheffield site (South Yorkshire, UK), Liberty Speciality Steels – the speciality steel business of newly formed Liberty Speciality Steels is improving its Liberty Steel – has been successfully producing alloy and specialist alloy manufacturing facilities by increasing stainless steel grades for over sixty years for use in de- production levels at the VIM X-eed® vacuum induction manding sectors such as aero space, oil & gas, industrial melting furnace supplied by SMS Mevac. This new met- engineering and in the manufacture of bearings, bright bar, allurgical facility produces high-purity steels and spe- narrow strip and niche engineering applications for custom- ciality alloys for extremely demanding applications like ers around the world. aerospace, motorsports and oil & gas. These facilities are coupled to a unique integrated mill, machined part Their strength in speciality steels lies in the fully integrated and service centre offering, and are supplied globally production capability, which includes electric arc steelmak- as ingot, bar, cut piece or machined part. ing, vacuum induction melting (VIM), mill processing capa-

The ingots produced will be refined further by processing through a vacuum arc remelting unit before being rolled or forged into products (Picture by courtesy of Liberty Steel).

3 LIBERTY SPECIALITY STEELS

bilities and dedicated service centres. Typical products in- of such materials Liberty Speciality Steels has been oper- clude ingots, blooms, billets, bars, slabs and narrow strip; ating numerous remelting plants, i.e. two electro-slag re- in cast, rolled, drawn, peeled, heat-treated or re-melted melting plants (ESR) and nine vacuum arc remelting (VAR) condition, in exactly the quantities required by customers. plants at the Stocksbridge site, with feedstock mainly provided by the nearby steelmaking operations. However, the The production centres in Sheffield and the West Midlands business previously supplied small quantities of VIM-derived area of the UK are backed by dedicated service centres in steel using ingots sourced from third parties. Bolton, UK, Nagpur, India and Suzhou and Xi’an in China. The service centres enable Liberty Speciality Steels to ser- Because of the enormous potential of the growing market, vice their customers’ supply chains with bespoke combina- in 2013 the company decided to invest in creating its own tions of added-value processing and just-in-time delivery. VIM base. In late 2013 the company announced it would More than 100 component and equipment manufacturers, build together with SMS group a vacuum induction melting end users, third parties and national bodies have validated (VIM) furnace at its Stocksbridge site to enable the steel the quality management systems. producer to tap into new market opportunities and develop on its own innovative new products for the aerospace and oil & gas industries. A challenging project had been launched. VIM plant enables Liberty Speciality Steels The company decided for a brownfield project. The furnace to deliver the highest purity steels location was the site of a former continuous billet casting plant, in order to take advantage of existing buildings, over- Liberty Speciality Steels has gained an excellent reputa- head cranes and plant services. The final layout integrated tion for supplying high-integrity steel to major commercial the main furnace components with the raw materials prepa- and military aerospace programmes around the world, using ration area, the crucible relining and pre-heating area and tailored supply chain solutions. Andrew Douglass, engineer- the mould preparation and ingot stripping area. ing director at Liberty Speciality Steels, underlines: “We are a key supplier to some very significant aerospace players.” He continues: “It is definitely a growth sector in terms of VIM: vacuum induction melting process aerospace production; Boeing forecasts a need for a record 41,000 new aeroplanes over the next twenty years. 38% of The VIM facility produces ultra-clean ingots, i.e. remelt elec- new planes will be for the Asian market, driven by China and trodes, that will be refined further by a remelting process, India.” Some of the most demanding products – delivered usually a vacuum arc remelting (VAR) unit before being rolled as ingot, bar and cut pieces – are used in the production or forged and finally manufactured into products such as en- of engine components, landing gear, controls, aerostruc- gine, transmission and structural components for the aero- ture, helicopter rotor components, etc. For the production space market.

Tapping and all other process sequences are remote controlled and monitored from the control room.

4 The VIM production route involves vacuum melting high-pu- After casting: the filled mould exits the casting chamber rity steel and alloys in a crucible furnace, and then vacuum on rail car to the stripping area. casting the purified liquid steel into ingot moulds – all with- After hours: the solidified ingots are stripped out and in a low pressure vacuum chamber (vacuum level approx. placed under insulated hoods to cool slowly. This pre- 0.05 mbar or even less). The VIM technique comprises con- vents cracking of sensitive steel grades. secutive process steps as follows: As the entire melting and casting operation is conducted in The upper furnace and lower crucible are sealed togeth- an oxygen-free atmosphere, the resulting steel is very clean er, evacuated and charged with raw material. and has very low gas content. The technology enables the The raw material is melted by electrical induction heating. achievement of very tight analytical tolerances. Alloying ad- Induced current stirs the liquid metal; exposing it to the ditions, also carried out under vacuum, allow for precise vacuum during hours of refining to remove gasses. control of the steel’s chemical composition. Alloying elements can be added under vacuum. Moulds are prepared and set. The moulds travel on rail Melting in an oxygen-free atmosphere prevents the forma- car into the casting chamber. tion of oxides and also the loss of elements with an affinity Launder/tundish are prepared and set. Launder/tundish for oxygen. Unwanted accompanying elements which have travel on rail to the casting chamber. a high vapour pressure can be removed. The ingots pro- Casting chamber is sealed and evacuated and connect- duced will be refined further by processing through a vac- ed to the melting chamber. uum arc remelting (VAR) unit before being rolled, or forged After setting the exact composition of the alloys and the into products such as engine, transmission and structural casting temperature, the liquid metal is tapped under vac- components for the aerospace market. uum. The furnace tilts forward to pour liquid metal via the launder/tundish into the mould during casting.

Production of speciality alloys at the Stocksbridge works, using the new VIM X-eed® unit supplied by SMS group.

5 LIBERTY SPECIALITY STEELS

Launder/tundish prepared and set for tapping under vacuum.

Technological concept and machine design All core components supplied by SMS Mevac have been designed to allow Liberty Speciality Steels to increase the melt The concept of the VIM unit is based on a three-chamber size to 18 t at a later date. system, in which casting, melting and exchange chambers are arranged adjacent to each other. The independent de- The mechanical vacuum pump system consists of three sign of the three chambers allows for individual evacua- skids that can be connected in parallel or alternately at tion of those. three exhaust points (melting chamber, casting chamber and exchange chamber/charger). To protect the vacuum The heart of the VIM X-eed® unit comprises an 8 t vacu- pumps against dust and metal particles, SMS group has um induction melting crucible and the associated vacuum developed special dry-type filters for this application. Sep- pumping, material charging and process control equipment. arate filter systems have been installed for each chamber.

6 Also ancillary equipment for crucible preheating and lining and electro-slag remelting (ESR). These facilities are cou- maintenance was included in the supply scope. The plant in- pled to an integrated rolling mill and service centres, which corporates vacuum pouring equipment for both top poured allow the company to deliver its products around the world and bottom poured ingots, in single or multiple ingot con- as ingot, bar, cut piece or machined part. Their highly qual- figurations. All process sequences are remote controlled ified technical teams provide advice and help with day-to- and monitored from the control room. The main process day problem solving, and are available to assist with lon- parameters and status indications as well as all important ger-term developments. system functions are displayed on the HMI monitor and are additionally recorded to permanent files for full quality as- Andrew Douglass, engineering director of Liberty Speciality surance traceability within the Level 2 process control sys- Steels: “We are delighted to have the VIM in operation and tem. The condition of the heat and casting operations are producing aerospace grades for sale and customer accep- visualized on separate video monitors using dedicated pro- tance trials.” Jochen Schlüter, managing director of SMS cess monitoring cameras. Mevac: “We are very proud of having installed and successfully commissioned the new VIM X-eed® facility in Stocks- bridge in close collaboration with Liberty Speciality Steels. Conclusion As partners of Liberty Speciality Steels, we will continue to render our extensive metallurgical expertise to support Liberty Speciality Steels takes pride in satisfying custom- our customer in developing and producing innovative higher and OEM requirements from state-of-the-art specialist end materials with the newly installed VIM X-eed® unit and alloy manufacturing facilities which include vacuum induc- responding successfully to the increasing requirements of tion melting (VIM) alongside vacuum arc remelting (VAR) this extremely exacting market.”

Liberty Speciality Steels SIMEC

Liberty Speciality Steels is a division of Liberty Industries SIMEC is a resources group spanning five continents and Group, part of the metals and industrials group Liberty encompassing major operations across shipping, infra- House. It employs 1,700 people at its major steel melt- structure, mining, energy and commodities. The busi- ing and processing sites in Rotherham, Stocksbridge and ness is part of the GFG Alliance and was established over Brinsworth, South Yorkshire, service centres in Bolton, 50 years ago by Mr Parduman K. Gupta, who remains Lancashire and Wednesbury, West Midlands and two dis- chairman. Latest SIMEC turnover exceeded US$ 2.7 bn, tribution centres in China. The business produces a range with net assets valued at US$ 796 m. of high-value steels made from recycled materials that are used in manufacturing components and finished goods for aerospace, automotive, oil & gas and industrial ma- GFG Alliance chinery sectors. The GFG Alliance is an association between PK Gupta and Sanjeev Gupta’s business interests to forge a new Liberty House agile, sustainable, non-cyclical, integrated, global business model. Its key focus is the creation of a resilient The Liberty House Group is an international industrials supply chain – from liquid metal produced from recycled and metals business specializing in commodities, metals scrap and renewable energy to highly-engineered prod- recycling and the manufacture of steel, aluminium and en- ucts, funded through a pioneering financial approach. gineering products. It operates from four hubs in London, The group encompasses: Liberty House Group – an in- Dubai, Singapore and Hong Kong and has presence in tegrated international industrial and metals business; more than 30 countries. Its current turnover is over US$ SIMEC Group – an international resources and infrastruc- 6.8 billion per annum. Liberty, along with its sister energy ture group; Wyelands – a banking and financial services company SIMEC, is part of the worldwide GFG Alliance. arm; GFG Estates – a division that manages the alliance’s property holdings; and GFG Foundation which is focused on the retention and creation of engineering skills.

7 LIBERTY SPECIALITY STEELS

Background information about VIM investment project

MPT International talked about the background of the VIM investment with Andrew Douglass, Engineering director, and Stephen Carey, manager Technology & Development, both Liberty Speciality Steels, Stocks- bridge, Sheffield, South Yorkshire (UK). The answers provide an insight into the company’s strategy in the respective market.

›› What is the total sum invested in the speciality steelmaking facilities at the Stocksbridgworks?

Andrew Douglass: There was recently significant investment in the business here in Stocksbridge. We probably invested £ 20…30 million during a period of approximate- ly five years in various finishing and heat treatment activi- ties – not all new facilities, but also refurbishing of existing plants. We upgraded the peelers, invested in the rolling mill. Here we built a central control pulpit to take all the oper- Andrew Douglass, Engineering director, says: “Aerospace ators away from the mill train. The new central pulpit has is definitely a growth sector. That was one of the key points when we designed the new VIM capacity.” been interfaced with the old mill controls. Additionally, we bought two new VAR plants and the VIM plant.

›› What was the basis for the decision in favour of the ratory melts to heats of 4 to 8 tonnes made on the new VIM VIM and why are you focusing on this technology? furnace. These are then processed and evaluated through our downstream processes. Andrew Douglass: Certainly, the target is always around the high added value. We had growth plans around supplies to the aerospace industry which would involve additional ›› How do you evaluate your footprint in the market vacuum capacity. That was one of the key points when we for aerospace products? designed the new VIM capacity and went for the option of a bigger crucible. The move from the 8 t to an 18 t crucible Andrew Douglass: The aerospace sector is very much an is very much in line with the aerospace growth plans. Aero- international market. The supply chain will go through some space is definitely a growth sector. We can see the growth, of the key aerospace players – OEMs, who supply compo- so it is important for us to act, because we are a key sup- nents to the aircraft companies. Our steel will be in the plier to some very significant aerospace players. components, like engines or landing gears, that the OEMs supply to the aircraft companies. We are already part of the Stephen Carey: In addition to routine commercial produc- global supply chain where business is based on long-term tion, the VIM furnace gives us the opportunity to develop supply contracts. We have established supply channels in new products and alloys. We can rapidly scale up from labo- various regions and countries to support that.

8 ›› What is your growth plan in terms of sales?

Andrew Douglass: We definitely have set ambitious tar- gets for strategic 5-year and 10-year growth plans for our aerospace segment. A lot depends on customer approvals. We want to broaden our range of steels to sell more. That’s one of the reasons for our investments in new technolo- gies, but also for future capacity increases.

There is a big pipeline of what we want to be able to offer in the future. Currently on the VIM we manufacture mainly 12 grades of alloy and stainless steels. We are increasing the value of what we are supplying, basically by adding higher alloys and more stainless grades to increase our portfolio.

It is important to note that we are already in the market with various of these grades. Now we are reaching out for additional customer approvals for grades that we are already producing. Also, with our new VIM plant we can add new Stephen Carey, manager Technology and Development: grades that we never made before, which include certain “The VIM furnace gives us the opportunity to develop new products and alloys.” alloyed steels and also super alloys.

The rational for our investment in the VIM was that previously we had been buying VIM ingots from 3rd party sup- ›› Do you produce materials with customized pliers to be remelted in our VAR shop. That gave us a foot characteristics? in the market. Some of our key customers have expected us to seriously enter into VIM products supply by setting Stephen Carey: Most of our products have to meet stan- up our own VIM production facility. That was part of our dard specifications like AMS or European standards, or growth plan. Now, as we have our own VIM manufacturing multiple classifications. These include products for very de- base, these customers consider us to be a more credible manding applications. The steels have to meet challenging supplier of VIM products. Since application of VIM products combinations of metallurgical properties, for use in helicop- is increasing, our market share for such product is increas- ter transmissions, formula-1 gears, etc. Most of these prod- ing, too. Had we not invested, we would have less opportu- ucts require production via the VIM-VAR route, to achieve nities with these key customers. Now, as we invested, we the required levels of cleanliness, analysis control and me- are on a more level playing field with some of our compet- chanical properties. We already have a number of existing itors. It will ensure our competitiveness over a long term approvals that we want to transfer to our new in-house and with a wider product range. production route.

As we now have the capability to produce larger quantities by the VIMVAR route, we can offer many more products for new applications in aerospace and other sectors.

9 LIBERTY SPECIALITY STEELS

›› Why did you decide for VIM technology from ›› Do you intend to continue investing in VIM-VAR plants? SMS Mevac? Andrew Douglass: Yes, absolutely. As explained before, the Stephen Carey: SMS group is highly regarded in terms general backlog of orders for new aircrafts and the pros- of their engineering. We have had close relationships with pects of emerging nations like China and particularly India the SMS group as our plant supplier in other parts of the is the base for our growth plan. It is an area where we see company. As this was to be the first VIM plant built by SMS positive market indicators. Mevac, there was a very good opportunity for us to work closely together with the engineers from SMS Mevac. This Our VIM facility is now being operated with a 8 t crucible, was a development project, where we could bring the op- but we intend to increase production using the originally de- erator’s perspective to the design. For us it was a brown- signed 18 t capacity. This new facility will enhance our port- field project. We had to design the facilities to fit into our folio and increase our production of the respective prod- existing site footprint. However, we had the opportunity to ucts. As all VIM production will go through the VAR – and start from a blank sheet and SMS Mevac were able to ac- our VAR capacity is full – we’ll have to think about addi- commodate our requirements in their layout design. Final- tional VAR plants if we increase our VIM production. Invest- ly, since this is a reference plant, it was designed to a very ment in additional plants is the logical answer. This way we high specification, in terms of vacuum performance, pro- can increase the size of the aerospace order book, which ductivity and metallurgical capability. is going to put some strain on other areas of our organi- sation. In parallel we have started to implement our plans Andrew Douglass: We are a highly credible supplier of VIM to automate a part of our testing regime for the aerospace steels to the aerospace industry. We are open for business. products, which because of their very nature are highly test We develop steels. All our customers know that there are intensive. Commissioning of some of the automated test two main (plant) suppliers to the VIM industry, and we can preparation equipment is already underway. Very soon, we underline that we opted for SMS Mevac because of the will go ahead with an investment in automated testing fa- credibility and because we have got a really good plant. We cilities, which will also further enhance our on-time deliv- both have a common interest, namely to make this proj- ery performance. ect a success. Yes, absolutely, we will continue investing in the VIM-VAR process route. It serves a growing market with good re- turns. It is one that we believe will acknowledge our expertise as product and service supplier and strongly underpin our commercial growth.

Thank you very much for the interview.

10 11 legal effect.Anobligation shallonly characteristics in if exist the of agreed thecontract.”to deliverexpressly havingterms products particular and,inparticular,characteristics asdescribed developments these may change ofthe Theprovision products. isnot ofthis information offurther intended asaresult to have andwillnot have may Theactualproducts not characteristics ofthe concerned. products always have provided inthisageneral information these brochurecontains description ofthe performance “The www.sms-mevac.com [email protected] Telefax: Phone: 45141 Essen,Germany 3a Bamlerstrasse SMS Mevac GmbH +49 2016323-200 +49 2016323-0