The process of seamless steel pipe manufacturers can be divided into two types: cold-drawn and hot-rolled. The production process of cold-rolled seamless steel pipe is generally more complicated than that of hot-rolled. The tube blank must first stop three-roll continuous rolling, and then stop the sizing test after extrusion. If the surface does not respond to the crack, the round tube will pass through the cutting machine to stop cutting, and cut the blank about one meter in length. annealing. Annealing is a very important link in the production process of cold drawn steel pipes. The quality of annealing not only affects the performance of the steel pipe, but also affects the removal of oxide scale. Therefore, it is necessary to equip a non-oxidizing bright annealing furnace for cold drawn fine steel pipes.
Fine seamless steel pipes are made of 10, 20, 30, 35, 45 and other high-quality carbon steels such as 16Mn, 5MnV and other low-alloy structural steels or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other composite steels by hot rolling or cold rolling. Pickling. In the pickling process of fine seamless steel pipes, black slag mainly composed of FE2O3 and FE3O4 is easily formed. In subsequent consumption, the appearance will form black spots. FE2O3 and FE3O4 are easily soluble in hydrochloric acid. In order to avoid the formation of dark spots, 5~10g/L NaCl should be added to the acid pool.
Thick-walled seamless steel pipes are commonly used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames, and steel scaffolding used in construction. Steel pipes are used to manufacture annular parts, which can improve the data application rate and simplify the manufacturing process. , To save materials and processing man-hours, steel pipes have been commonly used for manufacturing. Cold industry control for the production of cold drawn fine seamless steel pipes, including mold design, annealing, pickling, smoothing, etc. At the same time, we should do a good job in the quality inspection and decoration of the capillary tube.
The cold drawn fine seamless steel pipe has the characteristics of no oxide layer on the inner and outer walls, high pressure, no leakage, high precision, high brightness, cold bending, flattening, flattening without deformation, no cracks on the surface, and anti-rust treatment. Mainly used in the mechanical structure, hydraulic equipment, pneumatic or hydraulic components of automobiles and motorcycles. Detailed process flow: hot-rolled capillary inspection and grinding-capillary pickling-capillary pickling-post pickling-cold drawing-pre-straightening-pickling, smoothing-fine drawing-waste storage and pre-disposal.