Growth path № 2 November 2018

 

Progress in the steel industry will lead to improved steel alloys being widely used in advanced applications, so a successful future for the industry seems to be guaranteed.

Printing from steel

Today’s steel market is characterised by fierce competition, hence, companies have an incentive to constantly develop new products to meet continuously evolving customer requirements and demands. That being so, a priority for producers is to reduce the technological costs of manufacturing. One of the latest methods is industrial 3D printing.


 

Speaking about the versatility of modern steels, we should not forget their aesthetic qualities, which many designers and architects find indispensable. Decorative stainless steel, for example, is commonly used as a finishing material in public spaces.

The practical advantages of the material to designers include its ability to be used without further surface protection and also its ease of cleaning, which is very important for maintenance.

As for the artistic possibilities of stainless steel, specialists emphasise its suitability for polishing and texturing, which give it considerable potential in the creation of original designs. Interestingly, modern technology makes it possible to vary even the colour of steel, so it is capable of imitating gold, bronze or taking on sombre dark blue or black hues.

Decorative steel is particularly frequently used in hotels, restaurants, shopping centres, airports, and railway and metro stations.


 

A large-scale industrial production of metal 3D printers began in the late 1990s - early 2000s (the first models were made by the German company EOS). The aerospace industry immediately leapt at the possibilities offered by 3D printing. They were closely followed by automotive engine manufacturers, medical implant makers and others.

Alexey Merkushev, Head of additive technologies at the Regional Engineering Centre of the Ural Federal University, noted: “The advantages of 3D printing can only be exploited, if the charge material is of sufficiently high quality- the special stainless steel in powdered form. The 3D printing manufacturers have very specific requirements: the powder particles must be of the right size (25-30 microns diameter), spherical and smooth.”

The requirements are so strict to ensure the stability of the 3D printing process. Mr Merkushev added: “Not only the material itself is important, but also the temperature, the atmosphere inside the printer chamber and a number of other factors. Being able to control these parameters ensures high-quality finished products that are consistent from one batch to another.”

Currently, a number of Russian companies - PJSC Severstal, RUSAL, Polema and others - produce metal powders of the required specification. The printers themselves are designed by specialists of the Regional Engineering Centre of the Ural Federal University.


 

The first opportunity in response to increasing demand was to accelerate existing production processes. For example, whereas previously it might have taken ten years to make an aero engine by conventional means, now thanks to additive technologies the major manufacturers have managed to cut that time to two years. Moreover, 3D printing does not require any additional equipment, unlike traditional manufacturing methods like casting, forging or pressing, which saves money.

The 3D printers designed at our centre comprise by over 70% of Russian-made components. That includes complex parts such as lasers, which are made by IPG Photonics (NTO IRE Polus) near Moscow. It should be noted that just 15 years ago the efficiency rate of lasers used in 3D printing was at best 5%. Now the efficiency rate is above 35%, which makes it relatively economical to manufacture metal parts by additive layering.

Alexey Merkushev

Head of additive technologies, Regional Engineering Centre of theUral Federal University

Yet, there are still challenges slowing the adoption of 3D printing. They include the underdeveloped state of regulations governing the use of 3D printers in the industry and quality controls of finished products, there is also a lack of qualified personnel. However, these are all solvable issues. In particular, a few years ago the Ural Federal University launched a degree programme in Composite Materials and Additive Technologies, which will produce its first graduates this year. The university also runs training courses for employees of manufacturing companies who work with additive technologies.

Clearing the way

Whereas metal 3D printing is being developed successfully all over the world, other technologies, such as cold-resistant steels, are an authentically Russian speciality. The main driver behind this is the country’s commitment to explore the Arctic, which necessitates a considerable expansion of the icebreaker fleet.


 

Russia currently has three super-icebreakers under construction “Project 22220” (named Arctic, Sibir and Ural). The hulls are to be made of the latest cold-resistant steel designed by the Prometey Central Research Institute of Structural Materials, which was first presented in late 2017 at the international exhibition “Materials and Technologies for the Arctic”.

Steel quality is crucial in shipbuilding as the material is continuously exposed to the impact of sea water and large fluctuations in temperature; structures are subject to continuous dynamic loads. Metalloinvest produces steel products that meet all the requirements of shipbuilders: they have passed all the relevant tests and have a consistent chemical composition meeting both international standards and the requirements of the Russian Marine and River Registers.

Russia currently has three super-icebreakers under construction “Project 22220” (named Arctic, Sibir and Ural). The hulls are to be made of the latest cold-resistant steel

The production of innovative Arctic steel is characterised by technologies ensuring maximum homogeneity throughout the thickness of a finished rolled product comprising several layers without chemical reactions between layers.

These innovations enabled the steelmakers to apply thermo-mechanical treatments to sheets up to 150 mm in thickness. The result was an unprecedented combination of strength and plasticity, both of which can be specified to fit the intended purpose.

It is also important to say that the new technology serves to minimise the quantity of alloying additives (for example, molybdenum or nickel) necessary in steel of previous generations. Thus, the Arctic steel has only 1% of alloys, and as such substantially cheaper to produce than the alternatives.

Hull elements made from the new material will possess high strength and resistance to extreme temperatures, enabling the ships to traverse extensive ice fields.


 

Another excellent invention by the Prometey Central Research Institute of Structural Materials is an additional (outside) coating of stainless steel applied to the lower portion of icebreaker hulls to provide optimum abrasion resistance and active cathode protection against stray current. It was first used ten years ago on the nuclear icebreaker “Fifty Years of Victory”. Specialists say that, after all the time the ship has been at sea, its outer layer has lost barely a few microns in thickness, whereas on average a loss of 3-4 mm in a single season could be expected.

In cold-resistant steels we really are ahead of others. If you had to use, say, Korean steel in the hulls of gas tankers plying icy waters, they would become so massive they would be uneconomic to operate. That is no use to anyone. Whereas we offer cold-resistant materials to shipbuilders , that are far lighter and are still strong and resistant to below zero temperatures and corrosion.

Alexey Oryshchenko

Dr Tech. Sci., Head of the Prometey Central Research Institute of Structural Materials

Prometey’s innovative steels are useful for more than shipbuilding alone. They have also been used in, among other places, the ice-resistant Prirazlomnaya drilling platform, the first of its kind. It contains pipes made by the Izorsk Pipe Plant to Prometey’s specifications. As for the use of innovative products onshore, similar steels have been used in the construction of the Bovanenkovo-Ukhta gas pipeline which withstands severe conditions.

Mr Oryshchenko added: “Our specialists have studied many of foreign-made pipe steels commonly used in gas pipelines. However, these begin to rust within five or six years and pipes sometimes fail. Our pipes are 10-15% more expensive than the ones made from imported slab, but we guarantee 25 years of incident-free service.”

Test smelting

Cooperation between the industry and research organisations is particularly important for the successful development and testing of new steels. A good example of such cooperation is the steel smelting laboratory opened at OEMK as a joint project between Metalloinvest and the National University of Science and Technology MISiS.

The laboratory is currently carrying out experiments on a number of special steels and complex alloys. By creating a vacuum inside the furnace, or inert environment, specialists are able to eliminate admixtures from the working material so as to obtain very clean alloys which may become special steel products.

The possibilities of vacuum-induction furnaces are practically unlimited.

We can smelt entirely novel alloys and make inventions in both ferrous and non-ferrous metallurgy, but our principal role is to work together with Metalloinvest and OEMK in particular.

Nikolay Repnikov

deputy director for science and innovation at the Stary Oskol branch of the National University of Science and Technology MISiS

The smelted prototype materials are sent to the repair and mechanical section and the technical department of OEMK where they are thoroughly tested.

It is important to note that Metalloinvest and the National University of Science and Technology MISiS cooperate not only in the industrial research, but also on educational projects. For example, one group of students at MISiS is currently receiving a training in “Economics and Management at industrial companies” under a programme jointly written by lecturers from the institute and specialists from OEMK. The students gain not only the theoretical knowledge, but also a practical experience by undertaking internships at Metalloinvest.

A joint project by Metalloinvest and NUST MISiS has resulted in the opening of a steelmaking laboratory at OEMK

“The students of the Stary Oskol branch of the National University of Science and Technology MISiS are potential future employees of OEMK and Metalloinvest,” said Andrey Ugarov, Chief Operating Officer of Management Company Metalloinvest. “We are interested in attracting highly qualified specialists, so we strive to. create the right conditions for students to learn. Essentially, by investing in MISiS we are investing in the future of the industry.”

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