09CrCuSb welded pipe is a low-alloy steel welded steel pipe with excellent resistance to sulfuric acid dew point corrosion. It is widely used in flue gas desulfurization systems in power, metallurgy, chemical, and other industries. Through reasonable alloy design, this material adds elements such as Cr, Cu, and Sb on the basis of ordinary carbon steel, so that it exhibits excellent corrosion resistance in sulfur-containing flue gas environments and becomes a key material in environmental protection equipment.
1. Material properties and chemical composition analysis of 09CrCuSb welded steel pipe
The chemical composition of 09CrCuSb welded steel pipe is specially proportioned, in which the Cr (chromium) content is controlled between 0.50%-1.20%, the Cu (copper) content is 0.25%-0.45%, and the Sb (antimony) content is 0.05%-0.12%. This alloy combination forms a dense protective film on the surface of the steel, effectively blocking the erosion of corrosive media. Compared with ordinary Q235 steel, the corrosion rate in 60℃, 50% H2SO4 solution can be reduced by more than 80%, and the service life can be extended by 3-5 times. The material also has good welding and processing performance, with yield strength ≥295MPa, tensile strength ≥390MPa, and elongation ≥22%, which fully meets the mechanical performance requirements of structural parts.
2. Key technologies in the production process of 09CrCuSb welded steel pipe
The production of high-quality 09CrCuSb welded pipe involves a number of key technologies: first, the steel strip pretreatment process, using pickling and phosphating process to ensure the surface cleanliness of the substrate; second, high-frequency welding process control, the welding temperature needs to be accurately controlled between 1350-1450℃, and double gas protection (80%Ar+20%CO2) is used to ensure the quality of the weld; finally, the heat treatment process, 880℃ normalizing treatment is required after welding to eliminate welding stress. The current mainstream domestic manufacturers use the JCOE forming process to produce various specifications of products with diameters of 219-3000mm and wall thicknesses of 6-40mm, and the pass rate of ultrasonic flaw detection of welds reaches more than 99.5%.
3. Industry application status of 09CrCuSb welded steel pipes
In the power industry, 09CrCuSb welded steel pipes are mainly used in key parts such as the spray layer and flue gas reheater of the desulfurization tower of coal-fired power plants. A power plant transformation case shows that the equipment maintenance cycle is extended from the original 1 year to 4 years after the use of this material. The metallurgical industry is used in high temperature and high humidity sulfur-containing environments such as sintering machine head electrostatic precipitators and coke oven gas purification systems. It is worth noting that in the chemical industry, this material has also been successfully used in the manufacture of dilute sulfuric acid storage tanks, replacing traditional 316L stainless steel, and reducing equipment costs by more than 40%. According to the Baidu Baijiahao industry report, the market demand for 09CrCuSb welded pipes in my country will exceed 500,000 tons in 2024, and the annual growth rate will remain at around 15%.
4. Quality inspection standard system of 09CrCuSb welded steel pipe
This product implements GB/T2975-2018 “Steel Plate and Strip Resistant to Sulfuric Acid Dew Point Corrosion” standard, and meets the requirements of NB/T47003.1-2019 “Technical Specifications for Boiler Steel Structure Manufacturing”. Key inspection items include: intergranular corrosion test (according to GB/T4334), copper sulfate drip test (corrosion rate ≤3.5g/m2·h), weld X-ray flaw detection (Level II qualified), etc. Third-party inspection data shows that the annual corrosion amount of high-quality 09CrCuSb welded pipe in simulated flue gas condensate (pH=1.5) does not exceed 0.25mm, which is much better than the 2.0mm annual corrosion amount of ordinary carbon steel.
5. Market Selection Guide for 09CrCuSb Welded Steel Pipes
Consumers should pay attention to the following points when purchasing: first, check whether the manufacturer has a special equipment manufacturing license (TS certification); second, require the provision of the most recent third-party test report; and third pay attention to the actual alloy content test value of the product, especially the content control of the Sb element. According to the transaction data of the 51sole platform, the current mainstream market price range is 6800-8500 yuan/ton, which is significantly lower than similar imported products (about 12,000 yuan/ton). It is recommended to give priority to manufacturers with complete heat treatment equipment to avoid purchasing welded pipe products that have not been normalized.
6. Precautions for the installation and use of 09CrCuSb welded steel pipes
Engineering practice shows that the correct installation method directly affects the use effect of 09CrCuSb welded pipes: E309L series welding rods should be used during welding, and the interlayer temperature should be controlled below 150℃; the pipe support spacing needs to be shortened by 20% compared with ordinary carbon steel pipes to prevent vibration corrosion; when the system is shut down, the accumulated liquid should be drained in time to avoid excessive local concentration. A desulfurization project case shows that the use of cathodic protection (protection potential -0.85V) in combination with 09CrCuSb materials can further extend the equipment life to more than 8 years.
7. Future development trend of 09CrCuSb welded steel pipe
With increasingly stringent environmental protection standards, 09CrCuSb welded pipe technology continues to innovate: the new generation of products improves corrosion resistance by 30% by adding trace rare earth elements; the application of intelligent manufacturing technology realizes online real-time monitoring of weld quality; modular design promotes the formation of a standardized product system. Industry experts predict that with the advancement of the carbon peak policy, the application of this product in emerging fields such as waste incineration power generation and biomass power plants will show explosive growth from 2025 to 2030.
In summary, as an environmentally friendly material independently developed by my country, 09CrCuSb welded steel pipe has formed a complete production and application system through more than 20 years of technical accumulation. When selecting, users need to combine specific working conditions and conduct a comprehensive assessment from multiple dimensions such as material performance, manufacturing process, and testing standards to fully utilize its corrosion resistance advantages and provide long-term and reliable material guarantees for environmental protection facilities.
Post time: Jun-27-2025