Standard Upgrade Coupled with Technological Breakthroughs: Galvanized Steel Strand Industry Enters a New Phase of High Corrosion Resistance and Green Development
National Standard Revision Leads Industry Upgrade to Meet Rigorous Requirements of Multiple Scenarios
The one-year-long revision of the national standard GB/T 33363 "Prestressed Hot-Dip Galvanized Steel Strands" has made significant progress, and the new version is scheduled to be officially implemented in 2026, marking the full alignment of the industry's technical specifications with international standards. This revision integrates relevant content of GB/T 31314-2014 and implements multiple core optimizations to meet the new demands in the current engineering field: adding 1×19 structure (including Seale type and Warrington type) and 25.4mm specification products to fill the gap in lightweight applications in the 21.8mm~28.6mm range; in terms of mechanical properties, the 1×7 structure adds a new ultra-high strength grade of 2160MPa, the 1×19 structure extends to 1960MPa, the total elongation at maximum force increases from ≥3.5% to ≥4.5%, and the mining anchor cable requires ≥5.0%; the corrosion resistance is greatly enhanced, the upper limit of zinc coating weight is increased to 400g/m², the stay cable products clearly require ≥300g/m², and the neutral salt spray test determination method is introduced, while the marine engineering-specific products need to pass the 240h no-red-rust test. A relevant person in charge of the National Technical Committee of Standardization for Steel (SAC/TC183) stated that the new standard will effectively support the application of high-end scenarios such as wind power, marine engineering, and UHV, and promote the elimination of low-performance production capacity in the industry.
Accelerated Technological Iteration: High Corrosion Resistance and Intelligence Become Core Competitiveness
The upgrading of coating technology has become a key breakthrough in the industry, and the industrialization of Zn-Al alloy coating and rare earth microalloying technology is accelerating. By 2024, the number of domestic enterprises with mass production capacity of Zn-Al alloy coatings has reached 27, with a total annual capacity of 850,000 tons, accounting for 20.7% of the total capacity of high-strength galvanized steel strands, an increase of nearly 5 times compared with 2020. Among them, the Zn-8%Al-0.1%Ce coating system jointly developed by Fasten Group and Baowu Research Institute achieved 1850 hours of no red rust in the neutral salt spray test, with a tensile strength retention rate of over 1860MPa, and has been successfully applied in the Qinghai-Henan ±800kV UHV DC project. Research by the University of Science and Technology Beijing confirms that the annual corrosion rate of Zn-5%Al-Re coating in the simulated South China Sea atmospheric environment is only 0.85μm/a, which is far superior to the 2.3μm/a of traditional pure zinc coating, making it the preferred material for projects in coastal high-salt-fog areas.
The deep integration of intelligent manufacturing and online detection technology has promoted the dual improvement of product quality and production efficiency. Leading enterprises such as Hengxing Technology and Jiangsu Xingda have introduced closed-loop control systems based on AI algorithms, combined with machine vision and infrared thermal imaging technology, to real-time optimize parameters such as air knife pressure and cooling rate, controlling the coating thickness tolerance within ±5μm, increasing the first-pass yield to 97.6%, reducing zinc consumption by 12.1% compared with 2020, and the average industry zinc consumption dropped to 58.7kg per ton of products in 2023. In 2024, the first fully localized Zn-10%Al-Re coating intelligent production line was put into operation in Jiangsu Xingda. Through the replacement of domestic equipment, the investment payback period of a single production line was shortened to 5.7 years, breaking the monopoly of foreign-funded equipment.
Expanding Market Demand: New Energy and Overseas Markets Become Growth Engines
In the domestic market, the dual drive of new energy and infrastructure construction promotes demand growth. The southwest region has performed particularly prominently. The newly developed galvanized steel strands by Shuigang Jinke Company recently completed their first shipment, with 29.856 tons of products supplied to the Yunnan Chuxiong Guanyinshan photovoltaic bracket project. The total demand of the project reaches 300 tons, covering four specifications from φ15.2mm to 21.6mm, adapting to the needs of different load-bearing parts; during the same period, another 120 tons of φ15.2mm products were shipped to Chongqing for high-standard farmland construction projects. In the fields of UHV and coastal engineering, State Grid mandatorily required the use of Zn-Al alloy coating products in the new lines built in coastal areas of Fujian and Guangdong in 2024, driving the year-on-year growth of related orders by 142%; the demand for high-corrosion-resistance products in scenarios such as wind power and marine engineering further promotes the increase in the proportion of special galvanized steel strands.
Overseas markets have become a new growth pole, and the acceleration of certification mutual recognition and regional layout is advancing. In 2023, the T/CEC 5021—2023 "Technical Specification for High Corrosion Resistance Galvanized Steel Strands" formulated under the leadership of China Electric Power Research Institute obtained IECEE international mutual recognition, compressing the certification cycle for domestic products to enter the markets of "Belt and Road" countries to within 6 months. In 2024, China's export volume of Zn-Al alloy galvanized steel strands reached 123,000 tons, a year-on-year increase of 210%, mainly supplying high-end scenarios such as the Saudi NEOM new city power grid and the Vietnam LNG supporting power transmission project. Hengxing Technology plans to invest in the construction of a high-performance steel strand project in Vietnam to further expand the Southeast Asian market and avoid trade barriers.
Urgent Green Transformation: Low-Carbon Technology Becomes a New Competitive Track
Faced with the pressure of the full implementation of the EU Carbon Border Adjustment Mechanism (CBAM) in 2026 (requiring the carbon emission of galvanizing process per unit product to be less than 0.85tCO₂/t), the industry is accelerating low-carbon transformation. Hebei Iron and Steel Group's Tangshan Iron and Steel Base has built the world's first zero-carbon galvanizing demonstration line. Through photovoltaic direct power supply and hydrogen metallurgy reduction zinc vapor recovery technology, it has achieved a carbon emission of 0.32tCO₂/t, a decrease of 62% compared with the industry average. Many enterprises are promoting the transformation of electric heating zinc pots and waste heat recovery systems, and the utilization rate of green electricity is gradually increasing. Low-carbon production capacity has become a core threshold for participating in international competition.
Industry experts point out that in the next 5-10 years, the galvanized steel strand industry will evolve in depth towards "greenization + functionalization", and new technologies such as self-healing galvanized coatings and intelligent sensing coatings are expected to achieve breakthroughs. Enterprises need to focus on high-end material R&D, domestic equipment upgrading, and low-carbon process innovation to seize opportunities in standard upgrades and global competition, and provide more reliable material support for new energy, new infrastructure and other fields.