When the spiral steel pipe is welded, it is easy to form a coarse columnar crystal structure with strong directionality, which is conducive to the segregation of harmful impurities and elements, promotes the formation of intercrystalline liquid film, and improves the sensitivity of hot cracks. If the welding is heated unevenly, it is easy to form a large tensile stress and promote the generation of welding hot cracks.
The emphasis is on structural strength stiffness and inspection of structural nodes, connecting welds, bolts, and anchor bolts (anchor bolts). Check the screws (including rivets) of the billboard steel structure panel, the weathering and corrosion of the material. Advertising pictures of film structures should be repaired and reinforced for their firmness, weathering, and aging. The binding of the steel rope should be firm and reliable. Check lightning protection facilities and electrical safety devices to ensure safe and normal use.
Spiral steel pipe feeds the strip into the welded pipe unit. Through multi-roller rolling, the strip is gradually rolled up to form a round tube blank with an open space. Adjust the pressure of the kneading roller, control the welding space at 1-3mm, and make the two ends of the welding seam flat. If the space is too large, the proximity effect is reduced, the eddy current heat is lacking, and the weld grain indirection is poor, resulting in unfused or cracked.
If the space is too small, the adjacent effect will increase, and the welding heat will be too large, causing the weld to burn; perhaps a deep pit will be formed after the weld is kneaded and rolled, affecting the surface quality of the weld. Small and medium-sized steel, wire rod, steel bar, medium-diameter steel pipe, steel wire, wire rope, etc. , can be stored in a well-ventilated shed, but must be placed on a mat.
Some small steels, thin steel plates, steel strips, silicon steel plates, small diameter or thin-walled steel pipes, various cold-rolled, cold-drawn steels and high-priced, corrosive metal products can be stored in warehouses. The place or warehouse where spiral steel pipe products are stored should be clean and well drained, away from factories and mines that produce harmful gases or dust. Root out weeds and all debris on site and keep steel clean.
Large steel, rails, humiliating steel plates, large diameter steel pipes, forgings, etc. Corrosive materials such as acid, alkali, salt, cement, etc. shall not be accumulated in the warehouse. Different types of steel should be stacked separately to prevent mixing and touch corrosion. The warehouse should be selected according to the public’s situation. Generally, a closed warehouse is selected, that is, a warehouse with a roof wall, tight doors and windows, and a ventilation equipment warehouse.
Post time: Jun-29-2022