Influence of angle steel production process on mechanical properties of steel pipe

　　The production process of general angle steel can be divided into cold drawing and hot rolling. The production process of cold rolled angle steel is generally more complex than that of hot rolling. The tube blank shall be subject to three-roll continuous rolling first, and the sizing test shall be carried out after extrusion. If there is no response crack on the surface, the round tube shall be cut by a cutting machine to cut the blank with a length of about one meter. Then enter the annealing process. Annealing shall be conducted with acid liquid. During pickling, attention shall be paid to whether there is a large number of bubbles on the surface. If there is a large number of bubbles, it indicates that the quality of the steel pipe does not meet the corresponding standards. The appearance of cold-rolled angle steel is shorter than that of hot-rolled angle steel. The wall thickness of cold-rolled angle steel is generally smaller than that of hot-rolled angle steel, but the surface looks brighter than that of thick-walled angle steel. The surface is not too rough, and the caliber is not too much burr.

　　The delivery status of hot-rolled angle steel is generally that the hot-rolled angle steel is delivered after heat treatment. After the quality inspection, the hot-rolled angle steel shall be strictly selected manually by the staff. After the quality inspection, the surface shall be coated with oil, and then followed by multiple cold drawing experiments. After the hot rolling treatment, the perforation experiment shall be carried out. If the perforation diameter is too large, the straightening and correction shall be carried out. After straightening, it will be sent to the flaw detector by the conveyor for flaw detection test, and then it will be placed in the warehouse after labeling and specification arrangement.