Against the backdrop of global warming and accelerated development of polar resources, polar waterways are gradually becoming the "Ice Silk Road" connecting Eurasia. However, polar ship steel has long faced core challenges such as insufficient low-temperature toughness, poor welding performance, and weak impact resistance. Through continuous technological innovation and standard setting, China has successfully broken through the technical bottleneck of polar ship steel and provided a "Chinese solution" for global polar ship construction.
1. Technological breakthrough: from material design to process innovation
China's technological breakthrough in the field of polar ship steel stems from the precise control of the material microstructure and the comprehensive upgrade of the manufacturing process. Relying on the national strong foundation project, Anshan Iron and Steel Group has successfully developed F-class polar ship steel with a yield strength of 690MPa through the "ultra-low carbon microalloying + full-thickness cross-section temperature field coupling control" technology. The material can still maintain excellent impact toughness at -60°C, and the CTOD (crack tip opening displacement) value exceeds 2.8mm, far exceeding the requirements of international classification society specifications.
In terms of welding performance, research by the 725th Institute of China Shipbuilding Industry Corporation shows that the welded joints of 460MPa grade polar ship steel produced by the controlled rolling and controlled cooling (TMCP) process can still maintain a high fracture resistance at an extremely low temperature of -70°C. This achievement solves the problem of brittleness of traditional high-strength steel welded joints and provides possibilities for the lightweight design and construction of polar ships.
2. Standards Lead: China's Solution Becomes an International Benchmark
Behind the technological breakthrough is China's systematic construction of polar ship steel standards. The group standard "Guidelines for the Evaluation of Low-Temperature Steel for Polar Ships" (T/CIN 039-2024) issued by the China Navigation Society has for the first time clarified the chemical composition, mechanical properties, corrosion resistance and friction and wear resistance of polar ship steel. The standard not only fills the international gap, but also becomes the technical benchmark for global polar ship construction.
For example, in the mechanical property evaluation, the standard requires that the yield strength of polar ship steel at -70℃ should not be less than 500MPa, the tensile strength should not be less than 620MPa, and the fracture toughness characteristic value (δm) should reach more than 1.0mm. This indicator system far exceeds the existing international specifications and provides a solid guarantee for the safe navigation of polar ships.
3. Application practice: from scientific research results to engineering demonstration
The technological breakthrough of China's polar ship steel has been transformed into practical engineering applications. The FH420~FH550 grade thick ultra-high strength low-temperature resistant marine steel produced by Anshan Iron and Steel Group has been successfully applied to the world's first seventh-generation ultra-deepwater drilling platforms such as "Blue Whale 1" and "Blue Whale 2". The long-term service of these platforms in the Arctic waters has proved that China's polar ship steel can still maintain excellent performance stability in low temperature, high pressure and high corrosion environments.
In addition, the international standards "Design and Test Requirements for Ship Electric Heating Steel Doors" and "Design and Test Requirements for Ship Electric Heating Steel Small Hatch Covers" formulated by China Shipbuilding Group Guangchuan International further improved the safety of polar ship outfitting equipment. The application of these standards has enabled China's polar ships to reach the international leading level in operational reliability in extreme environments.
4. Global Competitiveness: The Internationalization of Chinese Steel
The technological breakthrough of China's polar ship steel has not only improved the competitiveness of the domestic shipbuilding industry, but also promoted the reshaping of the global polar ship construction pattern. At present, China has formed a product system of polar ship steel with three series and 58 grades, and has passed the certification of major global classification societies. These products have been exported to Russia, Norway, Brazil and other countries, and are widely used in the construction of polar tankers, LNG carriers and icebreakers.
Taking Anshan Iron and Steel Group as an example, its extremely cold environment marine equipment steel has produced a total of 750,000 tons since 2011, with sales revenue of 4.563 billion yuan and new profits of more than 500 million yuan. This achievement not only reflects the economic benefits of China's polar ship steel, but also highlights China's leading position in the global high-end marine equipment market.
5. Future Outlook: From Polar Navigation to Deep-Sea Exploration
As the commercial operation of the Arctic route accelerates, the demand for polar ship steel will continue to grow. China has launched the construction of the "Heavy Icebreaker Key Steel Collaborative Innovation Center" and jointly with Baosteel, China Classification Society and other units to carry out research on the wear resistance, fatigue resistance and crack arrest performance of polar ship steel. In the future, China will further promote the intelligent manufacturing and green application of polar ship steel, and provide more efficient solutions for global polar resource development and marine environmental protection.
The technological breakthrough of China's polar ship steel is not only a landmark achievement of China's shipbuilding industry from "following" to "leading", but also a key support for global polar navigation safety and sustainable development. In the journey of the "Ice Silk Road", Chinese steel is writing a marine legend of the new era with its excellent performance and reliable quality.