How to detect weld defects in stainless steel pipes

1. Welding omission refers to the situation where there are welding points that are not properly welded during the welding process. Welding omission is very likely to cause quality accidents. The true cause of welding omission is difficult to identify, and the entry point for solving the problem is unclear. The preventive measures can only be to strengthen self-inspection, increase on-the-move quality inspection and increase the frequency of final inspection to prevent the occurrence of welding omission and opening welds. Non-conforming products should not be transferred to the next process. 

2. To detect whether the welding material is leak-proof or not, a coloring inspection agent can be used. Coloring inspection is a type of non-destructive testing method, which is a surface detection method mainly used to detect surface damages such as cracks that cannot be identified by the naked eye, such as detecting surface defects (cracks) near the surface of stainless steel materials, pores, porosity, delamination, incomplete penetration and incomplete fusion (also known as PT inspection). It is applicable for inspecting the defects of dense metal materials (weld seams), non-metal materials (glass, ceramics, fluoroplastics) and the surface openings of their products (cracks, pores, etc.). 

3. The basic principle of colored penetrant inspection agent: Apply the coloring agent to the surface of the material, and the coloring agent penetrates into the damaged area. After a certain period of time, rinse off the coloring agent from the surface. Then apply the developer agent on the already cleaned surface. Due to the coloring agent having penetrated into the damaged area, the damage can be clearly seen. 

4. We use infrared weld leakage detection equipment to check for weld leaks. Infrared weld leakage detection is a non-destructive testing technology that measures the infrared radiation of components to obtain their surface temperature or temperature distribution, in order to determine whether there are internal defects in their operating status. If weld leakage is detected, the equipment will issue an alarm notification, and the production machine will automatically remove the stainless steel tubes corresponding to the alarm section to prevent the leaked stainless steel tubes from entering the next process. 

5. In addition, we also implement a hierarchical quality inspection process, where the next process supervises the previous one to prevent the occurrence of unqualified processes. The multiple levels of inspection ensure that the stainless steel pipes entering the market are of high quality, allowing users to use them with confidence.