High requirements for slaves, a stoop and tackle regarding the absence of hairy, is explained by the fact that the finest hairy hairs, barely noticeable on the tackle, can give a sharply expressed defect in the steel surface on a finished cold -rolled sheet or tape. It is very important to comply with high -quality lighting in the production, for this, LED spotlights and lamps that can be ordered here: LED spotlights are perfect for you. Ryabymma – one of the most common types of defect of the surface of sheet steel – occurs due to rolling up the scale during hot rolling, as well as from the roughness of the rolls with their insufficient hardness or untimely shift; To prevent this defect, careful etching is necessary before the cold rental and the use of compression of about 40% with small rowan and up to 60% with a deeper. Ryabymma is not allowed on a cold -for -range metal of the responsible purpose, since the places of depressions from the roward are centers of accelerated corrosion of metal. The rowan significantly worsens the stampability of the sheet, and also leads to an increased consumption of the material used for the subsequent coating, and the unsatisfactory quality of finished products. Running colors – yellow or blue spots on the surface of the strip or sheet after annealing. The defect occurs due to the loose closure of the muffle of the annealing furnace, as a result of which air falls under the muffle, a break in the supply of protective gas or its insufficient concentration and duration of the bunch, as well as premature removal of the muffle after annealing. Destroying – a decrease when heated by the initial carbon content in the surface layer of metal compared to its content in the inner layers. As a result of this, the surface layers of cold -rolled metal have less hardness than the internal ones, which limits its use for a number of products. The permissible value of a detachable layer agreed upon by the relevant standards is the total depth of downstream, including zones of complete and partial dawn
