Anti-Corrosion Upgrade Drives Demand Boom: Aluminum-Zinc Coated Steel Strand Industry Steps into a New Phase of High Corrosion Resistance Development

Since 2025, driven by the in-depth implementation of the GB/T 20492-2019 standard, the acceleration of UHV projects, and the large-scale development of offshore wind power, China's aluminum-zinc coated steel strand (zinc-5% aluminum-mixed rare earth alloy coated steel strand) industry has achieved dual breakthroughs in performance upgrading and market expansion. From bridge cables to new energy infrastructure, from intelligent production to overseas export, the industry is accelerating transformation centered on "high corrosion resistance, high strength, long service life, and greenization". The domestic market scale is expected to exceed 8.5 billion yuan in 2025 and climb to 13.5 billion yuan by 2030, with a compound annual growth rate (CAGR) of 9.7%, becoming a core growth driver in the high-end anti-corrosion wire and cable sector.​

Improved Standard System Leads Performance Iteration, Filling Technical Gaps in Multiple Scenarios​

The current GB/T 20492-2019 standard has established technical benchmarks for the industry by optimizing coating classification and strength indicators. Compared with the 2006 old version, the new standard has achieved three key upgrades: first, simplifying coating grades to two levels (A/B for steel wires) and three levels (A/B/C for steel strands), clarifying that Grade C coating (46-610g/m²) is suitable for high-corrosion coastal environments, filling the gap in marine engineering material standards; second, adding strength grades 4 and 5, raising the upper limit of steel strand tensile strength to 1960MPa to meet the requirements of high-strength scenarios such as main cables of long-span bridges; third, optimizing testing methods, introducing EDTA complexometric titration to accurately determine aluminum content (ensuring ≥4.2%), and adding a conversion formula for the breaking force of stranded wires, improving the testing accuracy of 1×7 structure products by 15%.​

The standard upgrade has directly promoted the leap in product performance. The current mainstream zinc-5% aluminum-mixed rare earth alloy coated products have 35 times higher corrosion resistance than traditional hot-dip galvanized steel strands, with a service life extended to more than 30 years, and can achieve 1850 hours of no red rust in neutral salt spray tests. Experts from the National Technical Committee of Standardization for Steel stated that the full alignment of domestic standards with international norms has accelerated the clearance of 30% low-performance production capacity, guiding the industry to concentrate on high-end anti-corrosion fields.​

Technological Breakthroughs Expand Application Boundaries, Multi-Scenario Demand Forms Growth Synergy​

With the dual advantages of "strength and corrosion resistance", aluminum-zinc coated steel strands have achieved in-depth penetration in multiple fields, forming a three-pillar demand pattern of "power + transportation + new energy".​

In the power sector, UHV and power grid upgrading have become core drivers. In the Hami-Chongqing ±800kV UHV project, 4,500 tons of aluminum-zinc coated steel strands are used for ground wire transmission. Their 1770MPa strength and Grade B coating (above 460g/m²) can resist strong wind vibration and day-night temperature difference erosion in the Gobi region. In 2025, the application proportion in the power industry has exceeded 60%, among which the demand proportion of UHV projects reaches 28%, and 1×19 structure products have become the mainstream configuration due to their adaptation to lightweight requirements.​

Breakthroughs in long-span projects in the transportation infrastructure field are particularly remarkable. A long-span suspension bridge in Guangxi adopts Grade 5 strength (1960MPa) aluminum-zinc coated steel wires to form main cable strands. Combined with a dehumidification anti-corrosion system, the theoretical service life of the structure exceeds 100 years, solving the traditional main cable anti-corrosion problem. Such projects have driven the demand proportion in the transportation field to rise to 25%, and the penetration rate of Grade C coating products in coastal bridge projects has increased from 32% in 2024 to 41%.​

Offshore wind power in the new energy sector has become a new growth pole. Targeting the high-salt-fog environment in the southeast coastal areas, enterprises have launched customized aluminum-zinc coated steel strands with an annual corrosion rate of only 0.85μm/a, far superior to the 2.3μm/a of traditional products, which have been mass-applied in the pile foundation fixing projects of offshore wind farms in Guangdong and Fujian. In 2025, the demand growth rate in the new energy sector reaches 18%, becoming the fastest-growing segment in the industry.​

Accelerated Intelligent and Green Transformation, Competitive Pattern Concentrates on Leading Enterprises​

The industry's technological upgrading presents a dual-drive characteristic of "intelligent manufacturing + green production". Leading enterprise Jiangsu Fasten Group has introduced AI closed-loop control systems and machine vision inspection technologies, controlling the coating thickness tolerance within ±5μm, increasing the product qualification rate to 99.7%, and reducing unit energy consumption by 18.7% compared with traditional processes. In terms of green production, Hebei Iron and Steel Group has reduced carbon emissions per ton of products by 22% through recycled zinc utilization technology and waste heat recovery systems, meeting the requirements of the EU Carbon Border Adjustment Mechanism (CBAM).​

The competitive pattern shows an obvious concentration effect on leading enterprises. In 2025, the industry's CR5 (market share of the top 5 enterprises) has reached 45%, with leading enterprises such as Jiangsu Fasten Group, Guizhou Wire Rope Co., Ltd., and Tianjin Huayuan dominating the market with patent technology and scale advantages. Small and medium-sized enterprises are facing dual pressures: on the one hand, raw material costs account for more than 60%, and a 10% increase in zinc ingot prices will lead to a 6.8% increase in production costs; on the other hand, the threshold for environmental protection technological transformation investment is high, forcing low-capacity enterprises to withdraw acceleratedly. It is expected that CR5 will rise to 58% by 2028.​

Multiple Breakthroughs in Overseas Markets, Initial Results of Global Layout​

Infrastructure demand along the "Belt and Road" has become the core driver of export growth. In 2025, the industry's export volume reached 32,000 tons, a year-on-year increase of 12%, among which the Southeast Asian market accounted for 41%, mainly supplying power grid upgrading projects in Vietnam and Malaysia. By participating in international standard mutual recognition, enterprises have shortened the product certification cycle to less than 6 months, successfully entered the Middle East market, and provided 1,200 tons of Grade C coated steel strands for Saudi Arabia's NEOM new city.​

To avoid trade barriers, leading enterprises are accelerating their overseas production capacity layout. Guizhou Wire Rope plans to build a 50,000-ton/year production line in Thailand, targeting the demand for offshore wind power and railway projects in ASEAN. It is expected that after commissioning in 2027, the tariff cost can be reduced by 12%-15%. Data from the China Nonferrous Metals Industry Association shows that in 2025, China's global market share of aluminum-zinc coated steel strands has reached 38%, and is expected to exceed 48% by 2030, making China the world's core supply base.