Titanium welded pipe is made by curling and welding titanium and titanium alloy coils or wide plates into a tube shape. Domestic brands include TA1, TA2 and TA10, while American brands include Gr.1, Gr.2 and Gr.12. The production process of titanium welded pipe is as follows: titanium strip uncoiling → shearing butt welding → loop storage → titanium strip cleaning → tube forming → welding → weld eddy current flaw detection → predetermined diameter → online annealing → precision sizing/straightening → Eddy current flaw detection→laser diameter measurement→online inkjet coding→cutting to length→ultrasonic flaw detection→precise length/flat head→air tightness test→finished product inspection→packaging and warehousing. titanium alloy pipe
The comprehensive advantages of titanium welded pipes. In China, the production technology of low-strength, low-alloyed titanium seamless pipes is relatively mature. In some pipes that need to withstand high pressure and structural stress, thick-walled titanium seamless pipes are generally used. However, due to factors such as low yield of titanium seamless pipes and long delivery cycle, vigorous development of titanium welded pipes has become a trend in the titanium pipe industry. Compared with titanium seamless pipes, the comprehensive advantages of titanium welded pipes are becoming more and more obvious. In Japan, the United States, Europe and other countries and regions, titanium welded pipes are gradually replacing titanium rolled pipes.
1. The mechanical properties of titanium welded pipes and titanium seamless pipes are basically the same
Taking titanium and titanium alloy tubes for heat exchangers and condensers as an example, the national standard is GB/T 3625-2007, and the American standard is ASTMB338. Titanium welded tubes and titanium seamless tubes differ in terms of chemical composition, mechanical properties, and process performance. Not much, even the same. With the advancement of titanium welded pipe welding and heat treatment technology, domestic thin-walled titanium welded pipes generally use single-gun or multi-gun TIG/PAW autogenous welding. After welding, an online heat treatment process is used. By optimizing the welding and annealing process, the base material and weld seam are , the microstructure of the heat-affected zone is basically close, while eliminating the welding stress and making the weld structure uniform. Through comparison, it was found that the composition of the titanium welded pipe weld is basically the same as that of the base material, and the mechanical properties and anti-corrosion properties of the weld are the same as those of the base material.
2. The appearance and quality of titanium welded pipes are better than titanium seamless pipes
Titanium welded pipes are welded by cold-rolled coils. They have uniform wall thickness, good concentricity, good smoothness, and are not prone to scaling in the pipes. Especially for thin-walled titanium tubes, the technical requirements cannot be met at all by the seamless rolling process. It is difficult for titanium seamless pipes to have a wall thickness of less than 1 mm after rolling or drawing processes; while titanium welded pipes can have a wall thickness of 0.5 mm or less, saving a lot of materials and costs. At the same time, due to the thinner wall thickness of titanium welded pipes, a higher heat transfer coefficient can be obtained and better heat transfer effects can be achieved.
3. Titanium welded pipes have outstanding cost and environmental advantages
The production process of titanium seamless pipes is complicated. Conventionally, three-roll or multi-roll rolling mills and drawing machines are used to roll or draw tube blanks of a certain specification in multiple passes, and finally the seamless pipes are produced after diameter and wall reduction. The production efficiency and yield of this process are low. Titanium seamless pipes are rolled or drawn from sponge titanium to pipes, resulting in a large waste of material and a yield rate of only about 50%. Large-scale mass production cannot be achieved and the production cycle is relatively long. Titanium welded pipes are produced through automated continuous production lines using titanium strip coils with uniform wall thickness through cold bending, welding, online heat treatment, sizing and straightening, non-destructive testing and air tightness testing. From titanium sponge to welded pipes, the material utilization rate is usually around 80%. If titanium coils are used as raw materials, the material utilization rate is over 95%. With the rapid development of the domestic titanium industry and the increasingly mature welding technology, the production efficiency of titanium welded pipes will also be greatly improved. The quality stability, consistency and production efficiency will be higher. They can be cut into required lengths according to customer requirements. , short delivery time, high material utilization rate, and unit cost will be lower than seamless pipes. Grade 9 Ti3Al2.5V Titanium Pipe
Titanium seamless pipes are usually produced by rolling or drawing processes. A large amount of rolling oil, drawing oil, etc. will be used in the production process, and the production site will be seriously polluted. After the titanium pipe is rolled and drawn, the grease and dirt on the inner and outer surfaces of the pipe need to be degreased and pickled. The pickling process causes greater environmental pollution. In order to ensure the health of operators and protect the environment, protective equipment and protective measures must be added, thus increasing capital investment and product production costs. Titanium welded pipes are continuously produced in large quantities through automated production lines, with stable quality and high production efficiency. Except for a certain amount of water, electricity and other energy consumption during the production process, there is almost no pollution to the environment.
In recent years, the development of the domestic titanium welded pipe industry has been restricted by raw materials and processing technology. The production technology of titanium welded pipes has been in the hands of professional manufacturers in Japan, the United States, France, Russia and other countries for many years. The development of titanium welded pipes in China started later than other titanium processed products, and the early development was relatively slow. Although titanium seamless pipes started early in China, their application is limited due to the many processing steps, long production cycle, low efficiency, and high cost of titanium seamless pipes. However, titanium welded pipes have high production efficiency and yield, and titanium welded pipes have high production efficiency and yield. The performance of pipe expansion and bending is similar to that of seamless pipes. Therefore, the usage of titanium welded pipes at home and abroad is increasing year by year, and its application in power station condensers is increasing.
In the early days of the development of titanium welded pipes, although China introduced a complete automatic production line for small-diameter titanium welded pipes from abroad, ending the history of China being unable to produce titanium welded pipes, the raw material for domestic production of titanium welded pipes, titanium coils, was completely dependent on imports and could not be provided. Strip blanks for thin-walled titanium welded pipes. At the same time, the sales price of foreign titanium strips is relatively high, which inhibits the production of domestic titanium welded pipes. In addition, due to the multiple impacts of technology introduction and digestion and raw material procurement difficulties, domestic titanium welded pipes have never been truly available in batches. Production capacity, the domestic titanium welded pipe market had not really taken shape at that time. In the past ten years, China's titanium welded pipe industry has developed rapidly, mainly due to major breakthroughs in the domestic production technology of titanium welded pipe raw materials - titanium coils. The technical performance indicators and quality stability of domestic cold and hot-rolled titanium coils, etc. Able to meet the requirements of titanium welded pipes.
The application fields of titanium welded pipes are constantly expanding. Titanium welded pipes have become the preferred pipe material in many industries to replace stainless steel pipes, copper-nickel alloy pipes and titanium seamless pipes. After several years of development, domestic titanium welded pipes have broken through a series of key process and technical bottlenecks and have been widely used in electric power, air conditioning, seawater desalination, water treatment equipment and other fields. In addition, domestic titanium welded pipes have also been exported in batches. It can be seen that the production technology and quality level of domestic titanium welded pipes have been greatly improved. As the understanding of titanium welded pipes deepens, the use of titanium welded pipes in the petrochemical industry will be recognized by the market, the scope of use will become wider and wider, and the market share will become larger and larger. Although the investment cost of titanium welded pipes is higher than that of commonly used fluid transportation pipelines, its cost is lower than that of titanium seamless pipes. From the analysis of the service life and maintenance cycle of titanium welded pipes, the investment cost of titanium welded pipes can be compensated in use. , the use of titanium welded pipes in pipeline systems can reduce production costs by reducing the number of regular maintenance, reducing production downtime, improving product quality, and extending pipeline life. Especially in recent years, the global titanium industry has not been very prosperous and competition has been very fierce. The price of titanium welded pipes has always been at a low level. Enterprises in the petrochemical industry have lower initial equipment investment costs when choosing titanium welded pipes.
