Since the production of sponge Titanium by magnesium reduction method in the United States in 1948, we have stepped into the golden age of titanium industry. Titanium has been widely used due to its light specific gravity, high strength, low thermal conductivity, corrosion and high-temperature resistance, weldability, no magnetism, and excellent properties. Due to its high production cost, the titanium hadn’t earned the wide application in the industrial field. In recent years, with the development of science and technology and the progress of production technology, titanium can be processed into various forms and applied in many fields. Titanium has become an indispensable material in aerospace, Marine, petrochemical, medical and other industries.
Titanium pipe can be divided into seamless Ti pipe and welded Ti pipe. Now the seamless titanium tubes in Chinese market generally adopt the vacuum annealing process of cold rolling, that means, the titanium ingot is made into the tube billet through forging bar billet, and then through multi-pass rolling and annealing process, finally the seamless titanium tubes are made. In recent years, China’s titanium welding pipe factories have been put into operation successively, and the production of titanium welding pipe increases year by year. However, the main domestic pipe manufacturers are mainly still produced seamless pipe, which is the mainstream in the market of applications.
Although the processing technology of titanium seamless tubes is mature, limited by the equipment behind developed countries, titanium pipes mainly use low-strength, low-alloy pure titanium or alloy Ti-Mo-Ni and other medium and low-strength alloy titanium as the base material and the cold rolling processing technology. Medium and high strength titanium alloy pipes, such as the Ti6Al4V pipe, need hot rolling which needs to install induction heating device on the rolling machine. For the pipes with special requirements, seamless pipe production became more difficult. For those thin-walled titanium and titanium alloy pipes or for super-long titanium pipes over 14m in length. In addition, the production of seamless titanium pipe requires many tools and abrasive tools and complicated equipment, resulting in limited production capacity and long production cycle of manufacturers, which cannot meet the market demand for thin-walled pipe, ultra-long pipe and low-cost pipe.
Based on the disadvantages of the titanium seamless tube mentioned above, the titanium welded tube emerges. As a relatively unique titanium tube product, the ti-welded tube is produced by the ti-rolled coil supporting tube, which is welded by the tungsten electrode inert gas protection. The biggest international titanium welding pipe companies include Japanese steel company and KOBE steel company, France’s Valtimet company, Russia’s VSMPO company and so on. In the mid-1980s, Xi ‘an BaoMei Farino welding pipe co., Ltd. established two automatic estimated advanced welding pipe production lines, and the company became the first welding titanium pipe manufacturer in China.
Compared with titanium seamless tube, titanium welded tube can be used to make pipe fittings with a thinner wall thickness, which can reach 0.3mm-0.5mm, while the minimum wall thickness of titanium seamless tube is about 0.9mm. At the same time, the raw material utilization rate of welded pipe, production efficiency and economic efficiency is better. As titanium material has excellent corrosion resistance to seawater, titanium welding pipe has gradually replaced stainless steel and copper alloy pipe to become the preferred material for condenser and heat exchanger. Therefore, it is widely used in coastal power plant, seawater desalination, Marine oil and other condensers and heat exchangers that need seawater as a cooling medium.
In European and American countries, the welded pipe used for condenser and the exchanger in coastal power generation and nuclear power plants has gradually replaced titanium thin-walled seamless tube. There are more research had been proved that titanium welded pipe has the more excellent performances than the seamless tube in the term of joint performance, compression performance, and anti-fatigue, which shows that the welding quality of welded pipe can satisfy the use of the harsh environment. Seamless titanium pipe is insufficient in the low yield and long production cycle and high cost compared with welded pipe, especially the production of commercial pure titanium welded pipe, it will be a new trend in the long run with its short, low production cost and high production efficiency.