Traditional Culture Encyclopedia - Weather inquiry - After welding another pipe fitting in the middle of 20 steel pipes, the end of 20 steel pipes cracked. What is the reason?

After welding another pipe fitting in the middle of 20 steel pipes, the end of 20 steel pipes cracked. What is the reason?

Wrong selection of welding process, including welding material, ambient temperature, groove treatment, welding current and voltage, preheating, heat treatment, welding speed, etc. , the welding process is specified by PQR; Welding defects must first be checked from the welding process.

2. The parent metal steel pipe is defective, that is, the steel pipe has cracks before welding, or the parent metal has problems, such as excessive hardness, which is the most likely.

3. The welding material is unqualified, such as the product does not pass the customs and is affected with damp;

4. The common causes of cracks are defects of base metal, hydrogen embrittlement of weld and low ambient temperature.