What is 09CrCuSb Cold-Drawn Alloy Steel Tube?
09CrCuSb Cold-Drawn Alloy Steel Tube is a low-alloy steel pipe specifically designed for resistance against sulfuric acid dew point corrosion. It is manufactured in strict accordance with GB 150.2 or GB/T 28947 standards and produced using precision cold-drawing processes, with dimensional tolerances controlled within ±0.05 mm to ±0.10 mm and surface roughness of Ra ≤ 1.6 μm.
In terms of corrosion resistance, under controlled laboratory conditions (70% sulfuric acid solution at 70°C for 24 hours), the corrosion rate is ≤ 14 mg/(cm²·h). Its acid corrosion resistance is more than 3 times that of ordinary carbon steel (20G) and approximately 1.8 times that of Japanese CR1A steel.
09CrCuSb steel pipes are widely used in power plant and industrial boiler systems, including economizers, air preheaters, shell-and-tube heat exchangers, and flue gas desulfurization (FGD) systems.
Manufacturing & Inspection Requirements of 09CrCuSb Cold-Drawn Alloy Steel Tube
09CrCuSb (ND Steel) is manufactured as seamless steel tubes to eliminate the risk of weld seam corrosion. To ensure maximum reliability in harsh acidic environments, the tubes are classified based on heat treatment condition and Non-Destructive Testing (NDT) levels.
Delivery Condition: Cold-drawn + full normalizing treatment to refine grain structure and completely remove internal stresses.
100% Eddy Current Testing (ET): Performed on all tubes to detect and reject surface or near-surface micro-cracks, in compliance with GB/T 7735 / ISO 10893-1.
100% Ultrasonic Testing (UT) (optional for high-pressure applications): Applied for boiler and critical heat exchanger services to ensure zero internal defects, in accordance with GB/T 5777 / ISO 10893-10.
Hydrostatic Pressure Test: Each tube is subjected to mandatory hydraulic testing (typically ≥ 5–10 MPa depending on wall thickness) to verify pressure-bearing integrity.
09CrCuSb Cold-Drawn Alloy Steel Tube Specification
Here is the structured specification table for 09CrCuSb (ND Steel) Corrosion-Resistant Seamless Steel Tubes, provided strictly in English:
| Item | Specification / Value |
| Specifications |
GB 150.2 (Pressure Vessels Part 2: Materials), NB/T 47019 (Technical Conditions for Boiler & Heat Exchanger Tubes) |
| Standard | GB 150.2, GB/T 28947, GB/T 3087, GB/T 5310 |
| Size Range | Outside Diameter (OD): 12.7 mm to 127 mm (Up to 426 mm for customized large-diameter seamless pipes) |
| Wall Thickness | 0.8 mm to 13 mm (Up to 36 mm for hot-finished heavy wall pipes) |
| Schedules | Equivalent to Sch 10S, Sch 20, Sch 40, Sch 80 (Mainly ordered by precise thickness in mm) |
| Grade | 09CrCuSb (Widely recognized globally as ND Steel) |
| Length | Single Random Length, Fixed Length, 3.0 m to 18.0 m maximum |
| End | Plain End (Square Cut), Beveled End (for welding) |
Dimensional Tolerances for Cold-Drawn Seamless Tubes
| Dimension | Nominal Range | High Precision Grade | Standard Grade |
|---|---|---|---|
| Outside Diameter (OD) | ≤ 30 mm | ±0.10 mm | ±0.15 mm |
| 31 – 50 mm | ±0.15 mm | ±0.20 mm | |
| 51 – 100 mm | ±0.20 mm | ±0.30 mm | |
| > 100 mm | ±0.40 mm | ±0.50 mm | |
| Wall Thickness (WT) | ≤ 2 mm | ±0.10 mm | ±0.15 mm |
| 2.1 – 5 mm | ±0.15 mm | ±0.25 mm | |
| > 5 mm | ±4.0% of WT | ±8.0% of WT | |
| Straightness | All sizes | ≤ 1.0 mm/m | ≤ 1.5 mm/m |
What is 09CrCuSb (ND Steel) pipe used for?
09CrCuSb (ND Steel) pipe is primarily used in low-temperature flue gas environments prone to severe sulfuric acid dew-point corrosion. Manufactured via cold-drawing for absolute seamless integrity, it is widely utilized for economizers, air preheaters, heat exchangers, and flue gas desulfurization (FGD) systems in demanding sectors like coal-fired power plants, petrochemical refineries, and industrial boiler manufacturing.
What is the inspection standard for 09CrCuSb (ND Steel) pipe?
The GB 150.2 and GB/T 28947 standards cover seamless low-alloy steel tubes specifically engineered for low-temperature sulfuric acid dew-point corrosion service conditions.
Its inspection criteria-detailed in the standard's quality assurance guidelines-include ultra-precise dimensional checks, comprehensive non-destructive testing (100% eddy current and optional ultrasonic testing), strict acid corrosion rate testing (70% H2SO4 immersion), mechanical property testing (tension/flattening/flaring), and mandatory hydrostatic testing.
If you are willing, please provide the following information:
The system's operating pressure and temperature, the pipe diameter and wall thickness (Schedule) you are considering, and the type of fluid or gas being conveyed. I can assist you in determining whether 9CrCuSb (ND Steel) material meets your project's parameter requirements.