Acid Resistant Steel Plate

09CrCuSb (ND Steel) Acid Resistant Steel Plate

09CrCuSb ND steel plate with excellent sulfuric acid dew point corrosion resistance for boiler economizers, air preheaters and heat exchangers.

09CrCuSb - known across the trade as ND steel - exists for one specific enemy: sulfuric acid dew point corrosion on the cold end of boilers. Chromium, copper and antimony in the chemistry give it several times the life of carbon steel where flue gas condenses into dilute acid. If your economizer or air preheater keeps thinning out every overhaul, this is the fix.

Grades and Standards

  • 09CrCuSb ND steel, produced per the Chinese sulfuric-acid-dewpoint-corrosion-resistant steel specification
  • Key chemistry: Cr, Cu, Sb additions; low sulfur and phosphorus

Sizes and Supply

  • Thickness 3-40 mm, widths 1000-2000 mm
  • Cut-to-size for preheater baskets, baffle plates and duct sections

Quality Documents

EN 10204 3.1 MTC with full chemistry. Comparative corrosion testing against plain carbon steel can be arranged for tender documentation - it makes the specification meeting go much faster.

Where This Plate Goes

  • Boiler economizers and air preheaters
  • Flue ducts and stacks in the condensing zone
  • Flue gas desulphurization internals
  • Waste heat recovery equipment

Questions Buyers Ask

Q: Why not just use weathering steel here? A: Different enemy. Weathering steel fights atmospheric corrosion; ND steel fights sulfuric condensate. They are not substitutes.
Q: How much longer does it last than Q235? A: Field experience in economizer service runs several times longer; the exact multiple depends on acid concentration and metal temperature, which is why we ask for your flue gas data.
Send flue gas temperature and fuel sulfur content with the RFQ - we will confirm ND steel is the right answer before quoting.