1. Performance and technology
Titanium welded pipes and titanium seamless pipes have little difference in chemical composition, mechanical properties, process performance and other indicators, or even the same. With the advancement of titanium welded pipe welding and heat treatment technology, 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, weld seam, The microstructure of the heat-affected zone is basically similar, while the welding stress is eliminated and the weld structure is made 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. Rolling and appearance
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. It is difficult for titanium seamless pipes to have a wall thickness of less than 1mm after rolling or drawing processes; while titanium welded pipes can have a wall thickness of 0.5mm or less, saving a lot of materials and costs.
3. Processing and industry applications
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 finished product rate of this process are low, and the finished product rate is only about 50%. 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. Material utilization is usually around 80%. 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.
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. At present, the titanium welded pipe industry has achieved rapid development and has been widely used in electric power, desalination, water treatment equipment, air conditioning equipment, petrochemical and other industries.
