Titanium tube and titanium clad steel tube sheet expansion joint process and welding process using manual tungsten argon arc welding. It is also proved by the manufacturing theory of liquid ammonia refrigerator that titanium tube and titanium clad steel tube sheet can obtain high-quality welds under the premise of selecting a reasonable manufacturing process. At the same time, it is the manufacture of titanium and titanium steel composite plate heat exchange equipment. Accumulated a certain experience.
Process test and welding process evaluation Titanium is an active element that can form a dense oxide film with oxygen at room temperature and maintain high stability and corrosion resistance. The oxide film formed above 540"C is not dense. Titanium reacts quickly with oxygen, nitrogen, and hydrogen at high temperatures, and it is easy to generate brittle substances, which makes the weldability extremely poor.
Therefore, in order to ensure the welding quality of the titanium tube and the titanium clad steel tube sheet, we started from the aspects of data and equipment structure, and obtained some data through process experiments and welding process qualification. The titanium-steel composite tube sheet and the titanium tube bundle adopt the manufacturing process of first expansion and then welding. In order to ensure the quality of product manufacturing, we have done the following process experiments.
Process experiment of tube sheet and tube bundle expansion joint The external cooler requires expansion first and then welding. The strength is guaranteed by the expansion joint, and the welding is mainly used for sealing. In order to ensure the strength of the expansion joint, we stopped the process experiment of the expansion joint between the tube sheet and the tube bundle. After the tube expansion experiment, we tested the expansion joint quality by measuring the pressure-release force, and confirmed the expansion joint number and expansion joint force and other process parameters to ensure that the expansion rate was within the range and met the design requirements.
