Compared with similar foreign products, there are still many gaps in China's stainless steel wire. Iron and steel enterprises must keep up with the market rhythm, develop new varieties, replace imports, and meet the development needs of the fastener industry.
However, domestic steel cannot meet the needs of the development of the fastener market in terms of quality, performance, variety and specifications. For example, rivets have developed rapidly in recent years, and are widely used in industries such as airplanes, ships, automobiles, machinery, household appliances, construction and decoration, and containers. The market demand is getting larger and larger. In the past, carbon-structured steel wire for cold forging was used for cold. It is made of alloy structural steel wire for upset forging, stainless steel wire for cold forging or non-ferrous metal wire. It has been developed to use all-steel blind rivets, all stainless steel blind rivets, Monel alloy rivets, etc. The products have high special requirements for tensile strength, shear strength and corrosion resistance, oxidation resistance and non-magnetic properties of steel, and some domestic steels are still difficult to meet. For example, stainless steel wire used in the manufacture of all-stainless steel blind rivets, there are still many problems in the domestic specifications, suitable for cold heading. The stainless steel wire imported from Korea and Japan is suitable for cold heading, and is solid solution treatment, pickled state delivery, no further environmental problems during deep processing, good processing performance and stable product quality.
With the rapid development of municipal construction, the application fields of fasteners continue to expand, market demand increases, and steel consumption is also increasing. For example, in recent years, the pace of localization of urban traffic rail transit equipment and rail transit vehicles has accelerated, requiring a large number of fasteners. For example, the magnetic suspension project of Shanghai, a national key project, has a total length of 30km and requires 1.5 million sets of high-strength bolts for fastening the connection between the magnetic suspension stator core and the girders. The steel used must be rust-free for 40 years, and its strength is also special. standard. To this end, Shanghai Wugang provides more than 800 tons of high-quality high-strength bolt steel. The fastener market is growing. In addition to plain carbon steel, stainless steel, high-temperature alloy steel, aluminum-magnesium alloy, Monel alloy, and the like are used for the fasteners. It seems that small screws and nuts are also developing rapidly. As above, Haishenguang High-strength Bolt Co., Ltd. is a specialized enterprise that produces high-strength bolting joints and cylindrical studs, welding studs, welding pins and anchors for arc stud welding, with an annual output of high strength for steel structures. There are 5 million sets of bolted joints and 20 million sets of welding studs for arc stud welding. The high-quality alloy structural steels used are 20MnTiB and 35VB. The nuts are made of 35# high-quality carbon steel, and the washers are made of 45# high-quality carbon steel. In addition, welding studs, welding pins and anchors used in shipbuilding, boiler, chemical, machinery and other industries are made of stainless steel or alloy steel.
Cold steel wire properties and uses:Cold heading steel wire is mainly used for manufacturing fasteners such as bolts, nuts, rivets and bolts. Its chemical composition and metallographic structure are relatively high. At present, the annual demand for cold rolled steel wire is about 1 million tons, of which the automotive industry needs 100,000 tons, but due to technical reasons, the domestic cold-rolled steel wire is only 300,000 tons, and it is imported nearly 700,000 tons per year. According to statistics, the demand for φ6.5mm or less is 150,000t, the φ8mm needs 160,000t, and the φ9mm and φ14mm each need 80,000t. At present, the domestic market is in short supply, which affects the production of fasteners. Therefore, China still needs to rely on imported fasteners to make up for the shortcomings every year. In 2000, China's fastener imports amounted to 93,400 tons, and the import value was 395 million US dollars, up 17.5% and 27.4% from 1999's 79,400 tons and 310 million US dollars respectively.
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