Quality control and inspection technology of welded steel pipe

The quality control and inspection technology of welded steel pipe is the key link to ensure the welding quality and product reliability. The following are some common quality control and inspection techniques:

1. Quality control before welding:
- Material inspection: inspection of steel pipe materials to ensure compliance with the required standards and specifications.
- Preparation: Confirm that the welding equipment is in good condition and the welding process parameters are set correctly.
- Preheating treatment: The steel pipe that needs to be preheated is properly preheated to reduce the risk of hot cracking.

2. Welding process quality control:
- Welding parameters monitoring: real-time monitoring of welding current, voltage, speed and other parameters to ensure that within the appropriate range.
- Weld morphology inspection: Observe the weld morphology to determine whether there are defects such as inclusions and pores.
- Welding process evaluation: Evaluate the welding process to confirm the rationality and feasibility of the process.

3. Quality control and testing after welding:
- Non-destructive testing: including ultrasonic testing, X-ray testing, eddy current testing, etc., used to find internal defects in welds.
- Hardness test: Measure the hardness of the welding area, judge the organizational state and welding quality.
- Metallographic analysis: The microstructure of the weld is observed through the metallographic microscope to evaluate the welding quality and performance.

4. Welding appearance inspection:
- Weld appearance inspection: Check the appearance of the weld and observe whether there are cracks, slag inclusion and other defects.
- Welding surface cleaning: to ensure that the welding surface is clean, no oil, oxide and other factors affecting the quality of welding.

5. Comprehensive quality assessment:
- Documentation: Complete quality management documents to record the quality control of each process.
- Quality feedback and improvement: according to the test results and actual production situation, timely adjust the process, improve equipment maintenance, and continuously improve the quality level.

The above quality control and testing technology should be combined with the specific welding process, steel pipe type and application requirements to ensure that the quality of the welded steel pipe meets the standards and meets the needs of use.