2 Floor,A Building,Tengdaxiang Technology Park,Xiner Zhuang Cun,Road No.2, ShaJing Street,Bao’an,District,Shenzhen,China
In order to reduce body weight and reduce fuel consumption, the use of high strength steels for bolts and screws has become a major development trend, and delayed fracture is the main technical obstacle to its development. Therefore, it is desired to develop steel products with delayed fracture properties, Secondary processing can improve the non-phosphorus coating. At present, the efforts of the development of the steel plant, non-phosphorus coating has been applied to the actual, but no phosphorus film heat-resistant strength, lubrication and anti-rust than zinc phosphate film difference in the future need to be further improved.
In recent years, iron and steel enterprises in steelmaking, continuous casting, slab dressing and hot forging and other processes to reduce surface scratches have achieved remarkable results. On the other hand, on the contrary, the coil in the transport process of overlap and transport, the process of surface scratches occurred in the process is relatively more obvious. As one of the measures, some do not use forklift handling, and some use of automatic three-dimensional warehouse, and achieved the effect of improving the surface quality. Rolling wires from steel mills are most worried about surface scratches during transportation. Therefore, various methods of preventing scratches are considered, and the simple packaging method for recycling the packaging material is indeed effective. In addition, there is the use of special-volume frame shipping. As a result of the global economic recession, the transportation distance becomes longer, the surface scratches the question to become more serious. These surface scratches may occur at all stages of the delivery roll and require a sustained effort by all concerned personnel to take a variety of subtle measures, such as the use of cushioning materials, to prevent surface scratches.
If the wire strength deviation, in addition to a direct impact on the bolt, screw strength deviation, but also on the bolt, screw shape and size of the subtle deviation. In order to reduce the cost, it is an important problem to reduce and improve the deviation of the strength of the steel wire in the case that the conventional cutting and grinding process is omitted, and the slight deviation of the shape and size of the bolt and the screw product may become a problem. Although the strict management of chemical composition has been achieved, but the steel wire manufacturers need to study a variety of measures to improve the heat treatment process throughout the wire uniformity.
Found in the cold forging process cracks, and sometimes require the use of naked eye to determine the law will crack all the bad products selected. In recent years, the surface scratches have become the main reason for cold forging cracks, which is characterized by short scratches length, the number is very small, sometimes a roll only 1-2 cracks. At present, it is a considerable burden for the steel mill to pick out all defective products with cracks by visual judgment. From the standpoint of a consistent cost competitiveness of materials to screw products, the development of a reliable, low-cost, automated pick and place inspection device that allows the use of innocuous minor defects is a future issue.