The main quality defects of cold rolled steel pipes include uneven wall thickness, oversized outer diameter, surface cracks, wrinkles, and rolling folds.
① Improving the wall thickness accuracy of the billet is an important condition to ensure uniform wall thickness of cold-rolled steel pipes.
② Ensuring the wall thickness accuracy and pickling quality of the pipe blank, lubrication quality, and surface smoothness of the rolling tool are important guarantees for improving the wall thickness accuracy of cold-rolled pipes. It is necessary to prevent excessive or insufficient pickling of the pipe blank, avoid the formation of rough surfaces or residual iron oxide scales on the surface of the pipe blank, strengthen the cooling of the rolling tool and the inspection of the tool surface quality, and replace unqualified core rods and rolling groove blocks in a timely manner.
③ All measures to reduce rolling force are beneficial for improving the outer diameter accuracy of steel pipes, including annealing treatment of pipe billets, reducing rolling deformation, improving lubrication quality of pipe billets, and surface smoothness of rolling tools. High-strength and hard materials are used to manufacture rolling tools, and cooling and inspection of rolling tools are strengthened. Once severe wear of rolling tools is found, they should be replaced promptly to prevent the outer diameter of steel pipes from exceeding the tolerance.
④ The surface cracks of cold rolled steel pipe generated during the cold rolling process are caused by uneven deformation of the metal. To prevent surface cracks in steel pipes during cold rolling, it is necessary to perform billet annealing to eliminate work hardening of the metal and improve its plasticity.
⑤ The magnitude of rolling deformation is crucial for the formation of surface cracks in cold-rolled steel pipes, and reducing deformation appropriately is a very effective method to reduce surface cracks in steel pipes.
⑥ Improving the surface smoothness of pipe rolling tools and the lubrication quality of pipe billets is a positive measure to prevent cracks in steel pipes.
⑦ Reducing the deformation resistance of the metal, reducing the amount of deformation, improving the quality of rolling tools and lubrication, etc. through annealing heat treatment of the pipe blank, is beneficial for reducing the occurrence of steel pipe bending and scratch defects.
Cold rolled steel pipe Manufacturers
Vigor can provide different materials such as alloy steel pipe, carbon steel pipe, non-ferrous metals such as L80, L80 9Cr-1 Mo, AISI4140, AISI4130, etc.
Vigor will provide you with a reliable solution, Please contact us at info@vigorpetroleum.com.
