Some precautions for repairing welding titanium pipes and titanium alloy pipes!

Release time：2023-03-28 16:57:56 丨 Number of visits：

In order to obtain titanium pipe castings and titanium alloy seamless pipes with good repair welding quality, the following points should be noted during the repair welding process:

(1) The surface of the repaired casting must be cleaned and dried, and it is not allowed to touch the casting directly by hand before it is loaded into the welding box.

(2) During the repair welding of titanium pipes, it is strictly prohibited to short circuit the tungsten electrode with the repair weldment, resulting in the breakage of the tungsten electrode and the occurrence of tungsten inclusions in the solder joint.

(3) When the area and depth of the repair welding area are relatively large, multiple distant welding should be performed, and the welding of the next layer should not be carried out until the previous layer of welding has completely cooled down. Single welding is not allowed to prevent deformation of the casting.

(4) At the end of repair welding, the current should be gradually reduced to narrow the melting zone. Therefore, it is recommended to use pulse current to prevent sharp arc break, leading to cracks.

(5) After completion of repair welding, the casting should be allowed to cool in the box for a period of time before being unpacked and taken out to prevent cracks or deformation in the welding area of the casting caused by rapid cooling; The length of cooling time depends on the wall thickness of the casting, typically between 15 and 30 mm.

(6) After repair welding of titanium pipe castings, they should be annealed or hot isostatic pressed in a timely manner, and should not be left for too long, usually no more than 5 days.

(7) The frequency of repair welding shall not exceed the provisions of relevant technical documents.

The titanium pipe manufacturer is required to repair welding titanium pipes in an environment where there is no flowing air. Other aspects are the same as repair welding in a welding box. However, special attention should be paid to:

(1) The repair welding area should not be too large, and the nitrogen flow during the repair welding process should be larger, without stopping the gas in the middle;

(2) After repair welding, nitrogen protection should continue to be applied until the area cools down;

(3) For some special castings, such as complex thin-walled castings, in order to prevent oxidation of the back surface of the repair welding area, argon gas can be blown on the back surface until the casting cools down;

(4) Repair welding operators are required to have a high technical level.