In foreign trade scenarios, the material selection and surface treatment process of Strain Triangle Yoke Plate need to meet international standards and user personalized needs, and details and applications are very important.
Carbon steel: It is a very common material with moderate cost and mature technology. The carbon content is 0.12%-0.22%. The toughness and strength are balanced. It can be formed by forging/CNC cutting. It has good welding performance and is suitable for mass production. After forming, it needs to undergo stress relief annealing (temperature 600-650℃, heat preservation for 2-3 hours) to eliminate cutting/welding residual stress and avoid deformation after installation;
Ductile iron: The core grades are QT450-10 and QT500-7, among which QT450-10 has a tensile strength of ≥450MPa and an elongation of ≥10%; QT500-7 has a tensile strength of ≥500MPa and an elongation of ≥7%. The fatigue strength is 20%-30% higher than carbon steel and can withstand 200 More than 10,000 times of cyclic load, graphite spherical distribution reduces stress concentration, outstanding impact and torsion resistance, suitable for large eccentric load conditions at the exit of corner towers and wind power towers, using sand casting + isothermal quenching, surface roughness Ra≤12.5μm, key hole positions require CNC secondary processing to ensure aperture tolerance ±0.5mm;
Aluminum alloy: The density of aluminum alloy is only 1/3 of steel. It is suitable for urban power grids, lightweight pole towers and other scenarios where load reduction is required. Taking into account both anti-corrosion and weight reduction requirements, 6061-T6 aluminum alloy is the first choice. The tensile strength is ≥310MPa, the yield strength is ≥276MPa, and the hardness can reach HB95-105 after aging treatment, which reduces weight. 30%-40%. It also has good corrosion resistance, non-magnetic and good conductivity. It is suitable for urban distribution networks and landscape lines. It can reduce the cost of pole and tower infrastructure construction. It is formed by extrusion/CNC milling. The surface does not require additional galvanizing and only requires anodizing treatment, simplifying the process;
Stainless steel: Stainless steel is suitable for highly corrosive environments such as coastal chemical zones and cross-sea lines. It is more expensive and is mostly used in special customized projects. The chromium content is ≥18%. A dense chromium oxide film is formed on the surface. It is resistant to acid, alkali and salt spray. It is suitable for offshore wind power and coastal transmission lines. It is laser cut and formed to avoid high-temperature welding from damaging corrosion resistance. The surface can be wire-drawn to improve wear resistance.
The core goal of surface treatment of Strain Triangle Yoke Plate is to improve corrosion resistance and extend service life. Different processes are suitable for different environments. In foreign trade, the anti-corrosion level needs to be clearly marked to meet customer bidding requirements. The following is a detailed parameter and effect comparison of 6 mainstream processes.
Hot-dip galvanizing: The most common production process of Strain Triangle Yoke Plate is hot-dip galvanizing. The zinc layer thickness is ≥85μm (about 600g/㎡), the adhesion is ≥7MPa, the salt spray resistance test is ≥500 hours, and there is no red rust in the neutral salt spray test for 1000 hours. The cost is moderate, the anti-corrosion life can reach 15-20 years, and it is suitable for regular environments such as inland and suburban areas. It is the basic anti-corrosion solution for global power grid projects;
Galvanizing + passivation treatment: The passivation film closes the pores of the galvanized layer to prevent the zinc layer from reacting with moisture and oxygen in the air to form white rust. It is suitable for foreign trade shipping projects and long-distance transportation orders in Southeast Asia, Africa, etc.;
Powder electrostatic spraying: dry film thickness ≥100μm, adhesion level 0 (cross-hatch method), weather resistance ≥1000 hours, color can be customized (RAL color card), rich colors, can match the color of poles and towers, improve the aesthetics of lines, suitable for urban core areas, scenic spots and other projects.
During the production process of Strain Triangle Yoke Plate, regardless of the material and surface treatment, it complies with international standards such as IEC/ANSI/GB, and provides a complete test report to meet customer bidding requirements. Materials (such as special grades of stainless steel) and anti-corrosion processes (such as Dacromet + powder coating) can be customized according to customer requirements to adapt to extreme scenes.
