There are many influences in the welding construction of pressure steel pipes, so there are many types of defects. If classified by the position of the weld, it can be divided into two categories: external defects and internal defects. External defects are located on the outer surface of the weld and can be seen with the naked eye or a low-power magnifying glass. For example, the weld size does not meet the requirements, undercuts, welds, arc pits, surface pores and surface cracks, etc. Internal defects are located inside the weld. This type of defect can be detected by destructive testing or non-destructive testing methods, such as incomplete penetration, internal pores and internal cracks, etc. If classified by the nature of the weld, it can be divided into three types: weld size does not meet the requirements: organizational structure defects, such as pores and cracks: performance defects, such as the mechanical properties and corrosion resistance of the welding head cannot meet the technical requirements.
In the manual arc welding method, slag inclusion, pores, and incomplete penetration are more common defects. For various defects, only by understanding its dangers and causes, and then taking corresponding measures to prevent defects and eliminate existing defects, can the welding quality be guaranteed.
Various welding defects will lead to stress concentration in the weld, shorten the service life, cause brittle cracks, and endanger safety. Therefore, in the production and installation of hydraulic pressure steel pipes, it is necessary to strengthen the control of welding work, abide by welding specifications, strictly follow the construction process, ensure the quality of welds, avoid welding defects, and ensure that the steel pipes are in a quality state from the beginning of production to the completion of installation and acceptance.
