Characteristics and precautions of TC4 titanium alloy tube

Generally, the environment for titanium heat exchanger tube manufacturers to repair and weld titanium tubes cannot have flowing air, and other aspects are the same as repair welding in a welding box. But special attention should be paid to:

1. The repair welding area should not be too large, the flow of nitrogen gas should be larger during the repair welding process, and the gas cannot be stopped in the middle;

2. After repair welding, nitrogen protection should be continued until the area cools down;

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

4. It is required that repair welding operators have a high technical level.

In order to obtain titanium tube castings with good repair welding quality, the following points should be paid attention to during the repair welding process:

1. The surface of the repaired castings must be cleaned and dried, and the castings are not allowed to be touched directly with hands before they are put into the welding box.

2. In the process of repairing titanium tubes, strictly prevent the short circuit between the tungsten electrode and the repaired parts, which will cause the tungsten electrode to break and cause tungsten inclusions in the solder joints.

3. When the area and depth of the repair welding area are relatively large, the remote layer welding should be divided into multiple times, and the next layer of welding can only be performed after the previous layer of welding layer is completely cooled. It is absolutely not allowed to weld in one time. Prevent casting deformation.

4. When the repair welding is about to end, the current should be gradually reduced to reduce the melting zone. Therefore, it is recommended to use pulse current to prevent sudden arc breaking and cracks.

5. After repair welding, the casting should be cooled in the box for a period of time before taking out the casting to prevent cracks or deformation in the welding area of the casting caused by rapid cooling; the cooling time depends on the wall thickness of the casting, usually 15-30mm.

6. After the repair welding of Grade 1 Titanium Tube castings, it should be annealed or hot isostatic pressed in time, and it should not be left for too long, usually no more than 5 days.

7. The number of welding repairs cannot exceed the provisions of the relevant technical documents.