Titanium in Shipbuilding and Other Technical Applications

Aerospace industry is currently the major consumer of titanium in Russia. Shipbuilding is its second largest consumer. Oil and gas, chemical, pulp-and-paper and other industries use less titanium. In the Russian industrial sector titanium is geting more applicable. Since the 13th World Ti-2015 Conference the titanium application trends have persisted [1]. Among the major development trends of titanium alloys one should note the development of titanium alloys for deep-water marine facilities, case designs of small-size nuclear power plants, the development of additive technologies, the technologies of isostatic pressing, the development of titanium products by new production facilities, etc. Titanium is still considered an advanced structural material used for scientific and technical progress in different industrial sectors.


Titanium in shipbuilding
Over the last years the construc on of large-size case designs of marine facili es made of tanium alloys has almost come to an end. Within this period Russia designed a few bodies of unmanned small-size research vehicles. There is no informa on on similar case designs manufactured by other countries.
Nowadays tanium is used in shipbuilding in designs of marine equipment and ship power engineering, such as: -tanium ship systems that consist of pipes and shutoff valves, pumps and filters; -desalina on plants and drinking water tanks; -propulsion systems (screw propellers, guiding devices and sha�ing) ; -deck machinery (cargo booms, winches, etc.); -exhaust systems cooled by sea water; -heat-exchange units of the ship power; -springs and fixing parts (bolts, screws, pins, etc.) (Fig.1).
Pipelines are the most widespread systems of marine engineering and power engineering. The wide range produc on of high-quality pipes made of tanium alloys and developed by Kurchatov Ins tute Research Center -"Prometey" Central Research Ins tute for shipbuilding was mastered in Ukraine in the Southern pipe plant located in the town of Nikopol.
The demand for tanium in shipbuilding has led to produc on of high-quality tanium pipes of the specified purpose by the Russian enterprises. https://doi.org/10.1051/matecconf/202032102001 The 14 th World Conference on Titanium  The study of the Russian pipe producing enterprises enabled us to select those being in full poten al of manufacturing high-quality pipes made of tanium alloys for the ship power engineering and the shipbuilding.
By now the different purpose pipe produc on technologies have been developed and mastered ( Fig.2) in Russia. For instance, such produc on facility located in Chepetsk Mechanical Plant ("ChMZ", located in Glazov), has developed the produc on of high-quality cold and hot formed tubes (Ø3 -325 mm) through a complete metallurgical cycle: ingots mel ng, tubular billets obtaining, and tube produc on [1]. "VSMPO-AVISMA Corpora on" located in the town of Verkhnyaya Salda manufactures both seamless pipes (up to 600 mm in diameter), up to 120 mm in thickness and welded 0.5÷1.2 mm thin-walled pipes.
It is well-known that the number of tanium applica ons is considerably limited by high cost of semi-finished products. Russia and other countries keep on reducing the cost of tanium products [3]. A major way to reduce it is to use secondary materials in the burden and economical alloying in combina on with improvement of manufacturing technologies of semi-finished and finished products. Secondary material is a qualified waste and scrap used in the burden for ingots mel ng. To tackle the issue of economical alloying, Russia has developed a concept of economically doped alloys based on strictly rated addi ves of oxygen and nitrogen to obtain alloys of high strength and duc lity [4]. USA and Japan have created economically doped alloys without expensive alloying elements to be used for civil industries [3]. Commercially efficient semi-finished produc on technologies based on electron beam remel ng and powder metallurgy are being developed. Addi ve and isosta c pressing technologies for irregular shape manufacturing are also promising. USA, China, France and Germany are the leading developers of addi ve technologies [6].

Titanium in nuclear power engineering
Titanium alloys as structural materials used in heat-exchange equipment of transport nuclear power plants (mul purpose steam generators, condensers and heat exchangers) began to be widely applied a�er a posi ve service experience of steam generators when short-life steel materials had been replaced with corrosion-resistant tanium alloys.
The present day applica on experience of tanium alloys and the full scope of research of their service characteris cs proved a wider use of tanium alloys for various systems of NPPs, including sta onary ones.
Titanium alloys began to be used in turbine plants (blades of the final low-pressure cylinder stage, generator tread rings, oil cooling heat exchangers, condensers of refrigerators, pipelines of chlorination systems and other equipment.
The nuclear power engineering enables titanium pipes to be used with thinner walls than those made of corrosion resistant steels and copper-nickel alloys due to the lack of corrosive wear allowances. The applications of titanium pipes have also economic benefits, since they prevent power losses and ensure circuit purity of the source water. Equipment range expansion of tanium alloys used in nuclear power engineering is related with heat-transfer elements performance growth and their failure-free service life.
A way to increase the heat transfer indicators of heat-exchanging equipment made of tanium alloys, including steam generators is to use semi-finished products with extended surface like ribbed pipes.
Produc on of the ribbed pipes for highly effec ve steam-generators is being developed now.
In addi on, some work is under way to replace steel with tanium in small and medium size reactor pressure vessels (RPV). Unlike steel, tanium has several technical, technological and economic advantages such as structure weight reduc on, no an corrosive cladding, minimum environmental impact, short repair me upon service life expira on, etc. Russia has a long experience of crea on and opera on of low power nuclear reactors used for shipbuilding. Integral type reactors are being designed today in which the en re primary loop equipment is encased inside a robust pressure vessel (Fig.3). Besides, such NPPs with a maximum amount of tanium can become basis of the power engineering in the Far North and the Far East regions. They can also support the oil and gas produc on, the Northern Sea Route and other hard-to-reach and extended areas and routes of Siberia.
Russia was the first to design a project of floa ng low power NPP, which is a new class of the nuclear power energy sources based on the Russian technologies of nuclear shipbuilding.
The first floa ng NPP named "Akademik Lomonosov" is equipped with two icebreaking-type reactor units that generate up to 70 MW and 50 gkal/h of rated heat energy to meet the needs of a town with a popula on of 100,000 people. The floa ng NPP "Akademik Lomonosov" is a towed 144 m long and 30 m wide vessel that is now being tested in the port of Murmansk (Fig.4). By the end of 2019 it will be delivered along the Northern Sea Route to its opera on site in the town of Pevek, Chukotka by the East Siberian Sea. https://doi.org/10.1051/matecconf/202032102001 The 14 th World Conference on Titanium

Titanium in other technical sectors
The use of tanium in shipbuilding and the available engineering development can be efficiently applied for other industries, like oil and gas, chemical, pulp-and-paper, etc.
Russia possesses prolific oil and gas fields on the shelves of the Sakhalin Island, the Barents, the Karsky, and the Okhotsk Seas. The Russian Arc c sea stock is one of the biggest reserves in the world that exceeds all the available hydrocarbon resources in the Middle East. The modern drilling and extrac ng floa ng pla�orms are the complex self-contained structures (Fig.5). Elements, life support equipment and technological process have the same func onality as those in ships.
The use of tanium elements for pla�orms is significantly restricted by the Arc c clima c condi ons, such as low temperatures (below -60°C), dynamic, corrosive and erosive influence of movable ice fields and https://doi.org/10.1051/matecconf/202032102001 The 14 th World Conference on Titanium wind loads. Besides, the structural materials have to be highly sustainable for ecological safety and high specific strength, considering that they are highly metal consuming.
Titanium alloys meet the specified requirements most of all in comparison with tradi onal materials that possess less reliability, specific strength and corrosion resistance. Titanium alloys can be used for the following oil and gas extrac on equipment: -pumps and intake systems of (sea), potable, drill and passing water; Apart from the above-men oned equipment, the use of tanium alloys is jus fied for riser systems and pressure piping to supply extracted products from underwater wells to pla�orms, vessel hoppers or transport ships. Low density in combina on with high yield strength and fa gue resistance makes it possible to considerably decrease thickness of pipe walls and tension force of riser systems that need no floa ng elements in deep water. The use of tanium alloys in pipe systems makes it possible to enhance the designed flow speed, to reduce cross-sec on of pipes and material consump on of systems. Titanium becomes more advantageous as oil and gas produc on gets deeper, because deep drilling requires lighter drilling rigs.
Some proper es of tanium can be a�rac ve for produc on of directed drilling pipes, well tools, etc. thanks to the combina on of its high specific strength and non-magne sm. Low modulus of elas city is favorable for risers and flexible pipe systems. The growth of serviceability of equipment made of tanium and its alloys considerably adds to the opera ng expenses and service life of equipment up to the life me of pla�orm or deposit field.
"Prometey" has developed a series of composite alloyed pseudo α -tanium alloys for marine applica ons of Ti-Al-V, Ti-Al-Zr, Ti-Al-V-Mo and other different categories of strength. These alloys possess high values of duc lity and toughness of bulk semi-finished products, high workability in semi-integrated shipbuilding, high corrosion and crack propaga on resistance in sea water, appropriate weldability without a subsequent heat treatment for stress relief. Service life of such equipment run in sea water is not less than 50 years. Many years of posi ve applica on experience of these alloys in shipbuilding have every reason to use them for various oil and gas produc on equipment. The use of tanium alloys in the elements of hydrocarbons producing off-shore structures helps extend their service life, which is some mes close to the one of the deposit field itself, increase serviceability, cut opera ng expenses of service and repair, reduce the weight of pla�orm equipment, and increase ecological safety. Pipe systems made of tanium of up to 400 tons in volume were used for the offshore pla�orm named "Prirazlomnoye" in the Barents Sea. Some pipelines were subjected to the surface thermal oxida on to protect the steel structures against contact corrosion. Titanium alloys were widely used in equipment of oil and gas produc on pla�orms on the shelves of Norway, Alaska, the Gulf of Mexico, etc. https://doi.org/10.1051/matecconf/202032102001 The 14 th World Conference on Titanium The use of tanium in the structures and equipment of chemical, pulp and paper, and food industries is growing in produc on of: -chlorine-containing compounds; -organic acids; -sulfuric acid; -ammonia; -oil processing products (petrol frac ons), etc.  The use of tanium for food industry is caused by its excellent bacteriological and ecological proper es. Storage tanks for juice, dairy produce, oil, wine, essence, and other food ingredients can be made of tanium.
Cellulose cooking (in acid or alkaline) and its whitening (in chlorine) are the basic manufacturing processes of the pulp and paper industry. Titanium is the best material to be used for the tanks (reactors, boilers and towers) in which these processes occur. "Prometey" has designed the technology and supported technically the manufacturing of bleaching towers by Bal c Shipyard (St. Petersburg) for a Finnish company. The towers had the form of cylinders up to 6.5 m diameter and up to 42 m high (Fig.6). Technical tanium in the grade of VT1-0 up to 20 mm thick was used as a base metal. Welding of the bleaching towers was performed by manual argon arc welding with VT1-00sv welding wire. Any service malfunc ons of the bleaching towers have not been recorded.

Summary
When being developed, materials and produc on technologies go through different stages, such as crea on, growth, advance and aging. Titanium alloys and their produc on technologies are on the advance stage nowadays [5]. It is featured by commercializa on and cost saving of tanium produc on and products. In addi on, tanium is s ll an advanced structural material that promotes scien fic and technical progress of industries.