Manufacturing process and application range of prestressed steel wire

Cold drawn prestressed steel wire is made of high carbon steel wire rod after surface treatment and cold drawing. The carbon content of the steel is selected in the range of 0.6-0.9. It must undergo pickling, phosphating or other forms of surface treatment before cold drawing. After cold drawing, the cross-sectional area will generally be reduced by 50 to 80 percent, and the strength is improved through the principle of cold working hardening.

If the cold drawn prestressed steel wire is stabilized, it will become a low relaxation prestressed steel wire, which has low relaxation characteristics and significantly improves yield strength, elongation and straightness. If it is galvanized, it will become a galvanized prestressed steel wire. The steel wire that is stabilized after galvanizing is called a low relaxation galvanized prestressed steel wire.

Steel wire is usually delivered in coils. When used in sleepers, it can be cut into bundles according to the needs. The diameter of prestressed steel wire is generally in the range of 4 to 12 mm. At present, 5 mm and 7 mm are commonly used in China. The high strength of this material is mainly in the axial direction, and the radial direction is significantly lower. When heated to 400 degrees or higher, the relaxation performance and strength performance will be significantly damaged.

When cold-drawn prestressed steel wire is used in pipelines, its stress corrosion resistance should be checked. When galvanized steel wire is used, its corrosion resistance should not be fully trusted, and the entire cable system should have other protective measures. Cold-drawn prestressed steel wire is generally used in pipelines, especially pipelines made by PCCP process.

Low relaxation prestressed steel wire is widely used in railway sleepers and prestressed concrete poles, a small amount is used in building components, and prefabricated beams are basically no longer used. Low relaxation galvanized prestressed steel wire is often used for cables of cable-stayed bridges, hangers of steel tube arch bridges, and prestressed cables for large-span buildings. Galvanized prestressed steel wire that has not been stabilized is generally used for cables of suspension bridges.