Circular Hollow Sections (CHS) are typically made through a process known as tube manufacturing. The specific method can vary depending on the type of material being used (commonly steel, stainless steel, or aluminum) and the intended application. Here is an overview of the general process of how steel CHS is manufactured:
Raw Material: The process begins with raw steel coils or sheets. These materials are typically made of low-carbon or mild steel, although high-strength and specialty steel may be used for specific applications.
Slitting: The steel coils or sheets are slit into strips of the desired width. The width of these strips will determine the size of the CHS produced.
Cold Forming: The strips are cold-formed into a circular shape through a process known as cold rolling or cold forming. This involves passing the strips through a series of rollers that gradually bend and shape the strip into a circular shape.
Welding: In many cases, the circular shape is achieved by welding a longitudinal seam. The edges of the strip are beveled to form a V-shape, and the two edges are then joined together through high-frequency induction welding, submerged arc welding, or another welding method. This seam welding creates a continuous, hollow tube.
Sizing and Shaping: After welding, the tube may go through further sizing and shaping processes to ensure it meets the required dimensions and tolerances. These processes involve passing the tube through sizing rollers or dies.
Cooling and Cutting: The formed and welded tube is then cooled to room temperature and cut to the desired length. The cut ends are often deburred to remove any sharp edges or burrs.
Finishing: The CHS may undergo additional finishing processes, such as straightening, heat treatment, and surface treatments (e.g., galvanizing, painting, or coating), depending on the specific application and requirements.
Quality Control: Throughout the manufacturing process, quality control measures are implemented to ensure that the CHS meets industry and customer specifications. These measures may include testing the weld integrity, inspecting the dimensions, and checking for defects.
