09CrCuSb welded steel pipe is a low-alloy steel welded pipe with excellent resistance to sulfuric acid dew point corrosion. It is widely used in flue gas desulfurization systems in industries such as power, metallurgy, and chemicals. Through a rational alloy design, Cr, Cu, and Sb elements are added to ordinary carbon steel, giving it excellent corrosion resistance in sulfur-containing flue gas environments, making it a key material in environmental protection equipment.
First, Material Characteristics and Chemical Composition Analysis of 09CrCuSb Welded Steel Pipe.
The chemical composition of 09CrCuSb welded steel pipe is specially formulated, with Cr content controlled between 0.50% and 1.20%, Cu content between 0.25% and 0.45%, and Sb content between 0.05% and 0.12%. This alloy combination forms a dense protective film on the steel surface, effectively blocking the erosion of corrosive media. Compared to ordinary Q235 steel, the corrosion rate in a 60℃, 50% H2SO4 solution can be reduced by more than 80%, extending the service life by 3-5 times. This material also possesses excellent weldability and machinability, with a yield strength of≥295MPa, tensile strength ≥390MPa, and elongation ≥22%, fully meeting the mechanical performance requirements of structural components.
Second, key technologies in the production process of 09CrCuSb welded steel pipes.
The production of high-quality 09CrCuSb welded steel pipes involves several key technologies: First, the steel strip pretreatment process uses pickling and phosphating to ensure the cleanliness of the substrate surface; second, high-frequency welding process control requires precise temperature control between 1350-1450℃, employing dual-gas protection (80%Ar + 20%CO2) to ensure weld quality; finally, the heat treatment process requires post-weld normalizing at 880℃ to eliminate welding stress. Currently, mainstream domestic manufacturers use the JCOE forming process, capable of producing various specifications of products with diameters ranging from 219-3000mm and wall thicknesses from 6-40mm, achieving an ultrasonic flaw detection pass rate of over 99.5% for welds.
Third, the current industry application status of 09CrCuSb welded steel pipes.
In the power industry, 09CrCuSb welded steel pipes are mainly used in key components such as the spray layer of desulfurization towers and flue gas reheaters in coal-fired power plants. A power plant renovation case shows that after using this material, the equipment maintenance cycle was extended from one year to four years. In the metallurgical industry, it is used in high-temperature, high-humidity, and sulfur-containing environments such as electrostatic precipitators in sintering machine heads and coke oven gas purification systems. Notably, in the chemical industry, this material has also been successfully applied in the manufacture of dilute sulfuric acid storage tanks, replacing traditional 316L stainless steel and reducing equipment costs by more than 40%. In 2024, the market demand for 09CrCuSb welded steel pipes in my country exceeded 500,000 tons, with an annual growth rate maintained at around 15%.
Fourth, the quality inspection standard system for 09CrCuSb welded steel pipes.
This product complies with GB/T2975-2018 “Steel Plates and Strips Resistant to Sulfuric Acid Dew Point Corrosion” standard and also meets the requirements of NB/T47003.1-2019 “Technical Specification for Boiler Steel Structure Manufacturing”. Key testing items include: intergranular corrosion test (according to GB/T4334), copper sulfate drop test (corrosion rate ≤3.5g/m2·h), and weld X-ray flaw detection (Level II qualified), etc. The annual corrosion of high-quality 09CrCuSb welded steel pipes in simulated flue gas condensate (pH=1.5) does not exceed 0.25mm, far superior to the 2.0mm annual corrosion of ordinary carbon steel.
Fifth, Market Selection Guide for 09CrCuSb Welded Steel Pipes.
Consumers should pay attention to the following points when purchasing: First, verify whether the manufacturer has a special equipment manufacturing license (TS certification); second, request the most recent third-party testing report; third, pay attention to the actual alloy content test value of the product, especially the Sb element content control. Currently, the mainstream market price range is 6800-8500 yuan/ton, significantly lower than similar imported products (approximately 12000 yuan/ton). It is recommended to prioritize manufacturers with complete heat treatment equipment and avoid purchasing welded pipe products that have not undergone normalizing treatment.
Sixth, Installation and Usage Precautions for 09CrCuSb Welded Steel Pipes.
Engineering practice shows that the correct installation method directly affects the performance of 09CrCuSb welded steel pipes: E309L series welding rods should be used during welding, and the interpass temperature should be controlled below 150℃; the pipe support spacing should be shortened by 20% compared to ordinary carbon steel pipes to prevent vibration corrosion; when the system is shut down, accumulated liquid should be drained promptly to avoid excessively high local concentrations. A desulfurization project case study shows that using cathodic protection (protection potential -0.85V) in conjunction with 09CrCuSb material can extend equipment lifespan to over 8 years.
Seventh, Future Development Trends of 09CrCuSb Welded Steel Pipes.
With increasingly stringent environmental standards, 09CrCuSb welded steel pipe technology continues to innovate: the new generation of products improves corrosion resistance by 30% by adding trace amounts of rare earth elements; the application of intelligent manufacturing technology enables online real-time monitoring of weld quality; and modular design has promoted the formation of a standardized product system. Industry experts predict that with the advancement of carbon peaking policies, the application of this product in emerging fields such as waste incineration, power generation, and biomass power plants will experience explosive growth from 2025 to 2030.
In conclusion, 09CrCuSb welded steel pipe, as an environmentally friendly material independently developed in my country, has formed a complete production and application system through more than 20 years of technological accumulation. When selecting materials, users need to consider specific working conditions and conduct a comprehensive evaluation from multiple dimensions, such as material performance, manufacturing process, and testing standards, to fully leverage their corrosion resistance advantages and provide long-term, reliable material support for environmental protection facilities.
Post time: Nov-28-2025