From Running To Running, The Development of Duplex Stainless Steel in China Has Made Great Progress
On September 19-20, experts and scholars from domestic and foreign stainless steel upstream and downstream related fields of scientific research institutes, universities, steel enterprises gathered in Beijing, around the hot topics of dual-phase stainless steel technology research and development, performance improvement, quality control, product research and development and application expansion for in-depth discussion. In order to promote the technological progress and high-quality development of duplex stainless steel in China, gather wisdom and seek a common future.
As we all know, duplex stainless steel is an alloy with the characteristics of austenitic and ferritic stainless steel, with high strength, high corrosion resistance, excellent welding performance and stability in various environments, and is widely used in many fields such as petrochemical, Marine engineering, paper and food processing and bridge bearing structure.
In China, for more than 90 years, duplex stainless steel has experienced hot processing performance, harmful phase and phase proportional control research, precise control of nitrogen and high purity smelting, two-phase performance balance design concept, low temperature impact toughness and strength toughness, rapid growth in production, alternative imports and application development. At present, China's duplex stainless steel shows a trend of increasing quantity, variety, structure and quality to high performance and high efficiency.
From the perspective of production development, the output of duplex stainless steel increased from 828 tons in 2005 to 393,400 tons in 2023, and the output reached 203,000 tons in the first half of 2024; The proportion of stainless steel production in China has also steadily increased, from less than 0.1% in 2005 to 1.07% in 2023; In the past five years (2019 to 2023), the annual compound growth rate of duplex stainless steel production was 21.4%, while the overall annual compound growth rate of stainless steel was 5.6% during the same period.
From the perspective of variety diversification, it has formed a complete product series of economic stainless steel, conventional duplex stainless steel, super duplex stainless steel, super duplex stainless steel and so on. Among them, 2205 duplex stainless steel has become the mainstream, while the production of economic duplex stainless steel and super duplex stainless steel is also increasing.
From the perspective of technological progress, through close cooperation with colleges and universities, scientific research institutes, steel peers, and downstream users, we have broken through key technologies such as high-strengthening preparation of economic duplex stainless steel, micro-alloying that takes into account the double improvement of high temperature strength and low temperature toughness, and composition and organization regulation that improve the deep drawing performance of cold plate. It also broadens its application field.
From the perspective of application field expansion, duplex stainless steel with its high alloy, high strength, high corrosion resistance, in consolidating and expanding the existing market demand at the same time, actively developing chemical tankers, oil pipelines, submarine hoses, Bridges and other emerging consumer markets have achieved obvious results, has become an indispensable raw material for high-end equipment in many fields.
In the field of chemical tankers, 2205 duplex stainless steel is often used, mainly for cargo bulkhead, heating coil support, cargo pump support, stairway structure, cargo cover, oil collection pan, etc., which has a number of advantages. First, with its high strength characteristics, it can reduce the thickness of the cargo hold, reduce the weight of the ship, increase the capacity of the ship, and create higher benefits. Second, it has the anti-corrosion characteristics of uniform corrosion, pitting resistance, stress corrosion resistance, corrosion fatigue resistance, which can make 2205 stainless steel chemical ship transport dozens of goods than carbon steel special coating ship, but also greatly improve the maintenance cycle and service life of the ship. The third is its low surface roughness, which can facilitate the cleaning of the ship's cargo hold and avoid the reaction between different chemicals caused by the residue of the goods, thus reducing the loading risk.
In the field of offshore petroleum engineering, duplex stainless steel is mainly used for key components such as underground production pipelines, injection devices for oil and gas Wells, offshore centrifugal separators, and submarine oil and gas transmission pipeline systems. The use of duplex stainless steel not only improves the durability and safety of related equipment, but also reduces maintenance costs, provides solid material support for the smooth progress of offshore oil engineering, and also brings significant economic benefits to offshore oil engineering.
In the field of plate heat exchangers, duplex stainless steel is mainly used for welding plate heat exchangers with relatively simple plate corrugated structure, often using 2205, 2507, 2101, 2304 duplex stainless steel, It has excellent mechanical properties, high surface hardness, excellent welding performance, good corrosion ability (relative to austenitic stainless steel) and relatively low price (relative to titanium plate and nickel-based alloy, super austenitic stainless steel). At the same time, the experts also proposed that the next step will be committed to applying duplex stainless steel to plate heat exchangers with more complex corrugated structures, and providing duplex stainless steel solutions for high-pressure gasket plate heat exchangers and all-welded plate heat exchangers. He also pointed out that he hopes to further optimize the formability of duplex stainless steel.
In general, in the future, China's duplex stainless steel will develop along the direction of high-alloy grade industrial new process preparation, process optimization, cost control and performance improvement, and application expansion in new fields. For the high-quality development of duplex stainless steel, the experts also put forward relevant suggestions.
First, it is necessary to strengthen innovation empowerment, drive industrial innovation with scientific and technological innovation, accelerate the transformation of new achievements, gather momentum, and generate more new productive forces. At the same time, it is necessary to enhance innovation capacity, increase investment in scientific research, strengthen basic research and applied research, break through key core technologies, and improve the position of China's duplex stainless steel industry in the industrial chain and value chain.
Second, we should base on our own advantages, actively adapt to market changes, dare to explore the "no man's land", actively serve the transformation and upgrading of downstream industries, grasp the rhythm of the development of new varieties and the iteration of product structure, continue to consolidate and enhance the competitiveness of the product market, while creating and expanding consumer demand, and promote the promotion and application of duplex stainless steel in key areas.
Third, it is necessary to speed up the construction of green, low-carbon and high-quality development of the duplex stainless steel industry chain. Including the establishment of various forms of exchange and cooperation docking platforms, and constantly expand and improve the user's awareness and recognition of duplex stainless steel, laying a good foundation for the further marketization of duplex stainless steel. At the same time, give play to the forces of all parties in the industrial chain, form a working force, and promote the integrated development of the whole industrial chain of duplex stainless steel, improve quality and efficiency.