The improvement method of improving the qualified

The improvement method to improve the qualification rate of cold heading steel wire rod

cold heading steel is mainly used to produce fasteners such as bolts and screws, which are widely used in many fields. At the same time, due to its good cold forming performance, it can replace hot rolling processing in the mechanical processing industry, saving a lot of man hours. At the same time, the metal consumption can also be reduced by%. The surface quality of finished products is very high, but it is easy to crack during cold heading production. The analysis shows that the cracking is not only caused by the scratch of rolled piece during rolling, but also caused by the corner crack of continuous casting slab. Need to be improved:

1. Optimize the casting process. In order to prevent corner cracks of continuous casting slab, continuous casting adopts the whole process protection pouring with the continuous increase of copper foil price. The submerged nozzle should be aligned to avoid flow deflection and local flushing of the condensate shell. Under the management of SGL Group, the maicafee research project was also promoted by the partners of the two projects, Augsburg University and BMW Group, resulting in a thin corner shell; Low superheat pouring is adopted to avoid intermittent boiling of water in the water gap of the mold and deformation of the shell when the superheat is large and the drawing speed is high, so that the average thickness of the shell is reduced; Check the crystallizer regularly to improve the water quality of the crystallizer, so as to avoid uneven cooling of the slab in the crystallizer

2. Strict rolling process. The rolling process is lean, so as to avoid the wear rate of the parts and avoid the surface defects of the rolled pieces in the middle pass. The roll, rolling groove and guide shall be updated in time to avoid affecting the rolling. Before UV curing, the guide inspection should prevent improper torsion angle or incorrect installation position, resulting in folding. Clean the oxide skin and metal hanging wire sundries in the production line to prevent scratching the rolled piece. The rolled pieces with ear and scratch defects shall be adjusted in time to ensure the quality of rolled pieces

3. Attention to other details. Avoid abrasion caused by friction and collision of wire on hard ground. During coiling and packaging, there shall be no crushing injury inside the reel, and soft tape must be used during hoisting to ensure surface quality

after the implementation of the above measures in Qingdao Iron and steel company in China, the qualification rate of cold heading steel wire rod has been greatly improved, which fully meets the requirements of users