What are the common quality issues of stainless steel welded pipes in the construction industry

The common quality issues of stainless steel welded pipes in the construction industry mainly include aspects such as material, appearance, dimensional accuracy, and welding. Here is a detailed introduction:

Material issues

Chemical composition not up to standard: The main alloy elements of stainless steel welded pipes, such as chromium (Cr), nickel (Ni), and molybdenum (Mo), do not meet the required levels, which will result in a decline in the corrosion resistance and strength of the pipes. For example, insufficient chromium content will cause the pipes to rust easily, affecting the durability of the building structure.

Uneven material distribution: During the production process of the pipes, there may be uneven distribution of the material. This will lead to differences in performance among different parts of the pipes, and they are prone to problems in weak areas when subjected to pressure or external forces. Appearance issues

Surface Scratches: During the production, transportation, handling, and installation of steel pipes, surface scratches may occur due to friction or collision with other objects. These scratches not only affect the appearance of the pipes but also may serve as the starting point of corrosion, reducing the corrosion resistance of the pipes.

Oxide Scale and Rust: If stainless steel welded pipes are not properly surface treated after production, or if they are exposed to humid and corrosive environments during storage and use, oxide scale or rust is likely to form on the surface. This not only affects the appearance of the pipes but also weakens their corrosion resistance and service life.

Weld Defects: Common weld defects include pores, slag inclusions, incomplete penetration, incomplete fusion, and cracks. Pores and slag inclusions reduce the density and strength of the weld, incomplete penetration and incomplete fusion make the weld connection unstable, and cracks are the most serious weld defect, which may cause the pipe to rupture during use.

Dimensional Accuracy Issues

Outer Diameter Deviation: If the outer diameter size of the steel pipe exceeds the allowable deviation range specified by the standard, it will affect the connection of the pipe with other pipe fittings, causing loose connections and problems such as water leakage and air leakage.

Wall Thickness Deviation: Uneven wall thickness or excessive wall thickness deviation will cause uneven stress distribution in different parts of the pipe when it is subjected to pressure, making it prone to rupture or deformation in the thinner parts.

Length Deviation: The length of the steel pipe does not meet the design requirements, which may cause difficulties in construction and installation, leading to unsatisfactory pipe connection and affecting the installation quality of the entire building piping system.

Performance Issues

Mechanical Performance Not Meeting Standards: The tensile strength, yield strength, elongation, etc. of the stainless steel welded pipe do not meet the requirements of the standard, which will cause the pipe to deform or break when subjected to external forces such as pressure in the building structure, affecting the safety of the building.

Insufficient Corrosion Resistance: In addition to the influence of chemical composition, improper production processes may also lead to insufficient corrosion resistance of the stainless steel welded pipe. For example, excessive heating during the welding process, uneven cooling, etc., may cause changes in the microstructure of the pipe and problems such as intergranular corrosion. Other questions

Uneven hardness: There are significant differences in the hardness of different parts of the steel pipe, which will cause some parts to deform easily during processing and installation, while others will be difficult to process, thereby affecting the quality and efficiency of the construction.

Unclear or incorrect markings: The markings on the surface of the steel pipe are unclear, incomplete, or have incorrect content, which will cause troubles for the construction personnel in material identification, selection, and installation, and may lead to incorrect use of materials, affecting the quality of the construction project.