1 Understanding Prestressed Steel Wire
Abbreviation related to steel wire used for reinforcing prestressed concrete structures
2 Categories of pc wire
(1) Based on Surface Shape:
Smooth round (smooth surface) and regularly deformed (notched, female thread, male thread, ribbed).
(2) By Processing Method:
Cold drawn, straightened and tempered, stabilized, cold rolled, quenched and tempered (oil, water, quenched).
(3) Based on Tensile Strength:
Low-strength low-carbon cold drawn wire has a tensile strength of less than 800MPa;
Medium-strength prestressed steel wire has a tensile strength ranging from 800 to 1470MPa;
High-strength prestressed steel wire has a tensile strength between 1470 and 1860MPa;
Ultra-high-strength prestressed steel wire possesses a tensile strength exceeding 1860MPa.
(4) By Cross-sectional Shape:
round, elliptical, semicircular, twisted ear, spline shaft type, etc.
(5) By Relaxation Level:
ordinary relaxation level (level I relaxation); low relaxation level (level II relaxation).
(6) By Surface Coating:
smooth surface without coating, galvanized, galvanized aluminum rare earth coating, epoxy coating, other coatings.
(7) By Chemical Composition:
carbon steel wire and low (micro) alloy steel wire.
3 Features of Prestressed Steel Wire
The carbon content of Prestressed Concrete Steel Wire typically ranges from 0.6% to 0.90%. It must comply with relevant national standards. The wire rod diameter ranges from φ6.5 to 14.0mm, and its metallographic structure is predominantly troostite structure, without martensite, network cementite, or any harmful structures.
Material Properties
To manufacture high-efficiency structural prestressed concrete steel wire, exceptional clean steel is required.
Prestressed concrete necessitates prestressed steel wire to exhibit comprehensive mechanical properties such as adequate tensile strength, outstanding toughness, high fatigue strength, and minimal stress relaxation. When using prestressed steel wires like PC steel wire, PC steel strand, and PC steel rod, it can significantly enhance concrete performance during usage while conserving steel, delaying the onset of cracks, minimizing crack width under high loads, reducing or eliminating deflection under load, and improving the shear strength and fatigue resistance of concrete products.
Raw Material Quality Control
Dimensional Control - Maintain consistency in rolling temperature across the same batch to minimize size fluctuations due to temperature-induced changes in deformation resistance. Implement micro-tension rolling to reduce dimensional accuracy issues. Optimize roller pass design to enhance error elimination during rolling and incorporate advanced technology for monitoring wire diameter deviations and ovality.
Surface Quality - Ensure proper billet grinding, remove surface defects from the billet, and prevent issues like scarring, cracks, and inclusions, which can be introduced during the wire drawing process.
Chemical Composition - Enhance the purity of molten steel through advanced steel-making processes and refine the chemical composition accurately to minimize impurities.
Cleanliness - Enforce strict control during ladle refining and continuous casting processes to remove non-metallic inclusions and achieve high cleanliness standards.
Segregation - Use modern techniques during continuous casting to minimize center segregation and avoid formation of banded structures.
Uniformity - Implement various technologies to ensure high uniformity throughout the steel manufacturing process.
Metallographic Structure - Use controlled rolling and cooling techniques to achieve a favorable metallographic structure for drawing and cold heading.
Inspection and Delivery
Inspection items include chemical composition, mechanical properties, surface quality, dimensional deviations, segregation, decarburization, grain size, and cleanliness.
4 Application of Prestressed Steel Wire
Prestressed steel wire is primarily used in industrial buildings, high-rise structures, prestressed buildings, various types of foundations, reconstruction and reinforcement of building columns, prestressed steel frameworks, and bridges on roads and railways. Additional applications include urban overpasses, containment structures for nuclear power plants, communication towers, water towers, concrete silos, sewage treatment facilities, geotechnical anchoring projects, and water conservancy and hydropower initiatives. The scope of applications continues to expand.
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