the forming process of LSAW straight seam welded pipe needs to go through many steps to form slowly. After the straight seam welded pipe is produced, it also needs to be tested. The main methods to inspect the quality of longitudinally welded pipes are:
1. Magnetic inspection can only detect defects on the surface or near the surface of longitudinally welded pipes. Only quantitative analysis can be done on defects, and the nature and depth of defects can only be estimated. According to the different methods of measuring magnetic flux leakage, it can be divided into magnetic particle method, magnetic induction method and magnetic recording method, and magnetic particle method is the most commonly used.
2. Ultrasonic inspection method is based on the difference between ultrasonic metal and other homogeneous media.
3. Penetration inspection is the use of physical properties such as the permeability of certain liquids to find and detect defects.
4. Radiographic testing is to use the ray to penetrate the material and the attenuation characteristics in the material to perform detection.
Because it is characterized by strong earthquake resistance and pressure resistance, and new environmental protection, many large-space, large-span buildings such as stadiums, subway stations and large-scale Industrial plants are built with it, so the application in the construction industry is very extensive. Although the production process of straight seam welded pipe is simple, efficient, and low in cost, it can only be used in thinner and small-diameter steel pipe materials, and cannot be used in thicker and large-diameter steel pipe materials to produce thicker and large-diameter steel pipe materials. The steel pipe material can only use the spiral welding process.
