09CrCrSb(ND) SEAMLESS STEEL TUBE FOR ANTI-ACID LOW TEMPERATURE DEW POINT CORROSION
ND steel is one new-style low alloy structural steel. Compared with other steel, like low carbon steel, Corten, CR1A, ND steel has excellent corrosion resistance and mechanical properties. The results show that in the aqueous solution of vitriol, hydrochloric acid and sodium chloride, the corrosion resistance of ND steel is higher than carbon steel. The most prominent feature is that it has strong ability of anti-acid dew point corrosion. From indoor temperature to 500℃, the mechanical property of ND steel is higher than carbon steel and steady, the welding property is excellent. ND steel is usually used to manufacture economizer, heat exchanger and air heater. From 1990s, ND steel is widely used in the industries of petrifaction and electric power.
09CrCuSb (ND steel) resistant to sulfuric acid low temperature dew point corrosion steel (ND steel, ND steel, 09CrCuSb steel, 09CrCuSb steel, etc.). Usually called 09 club.
09CrCuSb (ie ND steel) Standard:
Q/TDGG0039-2004—–Industry internal standard
GB 150.2-2011 – Pressure Vessels Part 2
09CrCuSb (ie ND steel) Grade:
09CrCuSb (ND steel pipe)
09CrCuSb (ie ND steel) Chemical Composition:
|
Grade
|
Chemical Composition(%)
|
| C |
Si |
Mn |
Cr |
Cu |
Sb |
P |
S |
| 09CrCusb |
≤0.10 |
0.20-0.40 |
0.35-0.65 |
0.70-1.20 |
0.25-0.45 |
≤0.10 |
≤0.10 |
≤0.10 |
09CrCuSb (ie ND steel) Mechanical Properties:
|
Grade
|
Tenslle Strength(MPa) |
Yield Strength(MPa) |
Elongation(%) |
|
09CrCuSb
|
390-550 |
≥245 |
≥25
|
09CrCuSb (ie ND steel) Chemical composition in GB 150.2-2011:
|
09CrCuSb
|
| C |
Si |
Mn |
P |
S |
Cr |
Cu |
Sb
|
|
≤0.12
|
0.20~0.40 |
0.35~0.65 |
≤0.030 |
≤0.020 |
0.70~1.10 |
0.25~0.45 |
0.04~0.10
|
Corrosion resistance
In sulfuric acid of medium temperature and concentration, ND steel is passivated due to dissolution. A passivation layer rich in Cu, Cr, Sb and other metal elements is formed on the surface of ND steel, which has high sulfuric acid corrosion resistance.
Comparison of corrosion rate between ND steel and other steel grades (70 ℃ – 50% H2SO4 solution)
| Steel Grade |
09CrCuSb（ND steel） |
CRIR(Japan) |
1Cr18Ni9 |
Corten |
STEN（Japan） |
A3（Q235B）
|
|
Corrosion rate
|
7.30 |
13.40 |
21.70 |
63.00 |
27.4 |
103.50 |
| multiple |
1 |
1.84 |
2.97 |
8.63 |
3.75 |
14.11
|
ND steel pipe (09CrCuSb) shall be tested for corrosion resistance
ND steel pipe (09CrCuSb) shall be subject to corrosion resistance test. One sample shall be taken from each batch of two steel pipes, and each sample is a 10 mm long pipe section. Soak in 50% H2SO4 solution at 70 ℃ (± 2 ℃) for 24 hours. The average corrosion rate of two samples shall not be greater than 80g / ㎡ * h or 140g / ㎡ * h, and the specific index shall be indicated in the order.
09CrCuSb welding material:
The carbon equivalent of 09CrCuSb is moderate, the content of S and P is not high, so its welding performance is good, preheating is not necessary during welding, and heat treatment is not required after welding ND steel special NDS electrode is used for welding.
09CrCuSb (ie ND steel) Specification:
|
Specification
|
Specification
|
|
19*2-4mm
|
76-114 * 4-10mm |
|
25 * 2-4mm
|
133-140 * 6-14mm
|
|
32 * 2-5mm
|
159-219 * 21-35mm
|
|
38-42 * 3-5mm
|
273-325 * 7-50mm
|
| 51-63 * 3-5mm |
356-630 * 10-20mm
|
09CrCuSb (ND steel) steel is developed for coal-fired boilers, oil-fired boilers; heat exchangers for electric furnaces, pipes, chimneys, boiler air preheaters, economizers, heat exchangers, condensing coolers, evaporators, etc. Hot-rolled steel sheets and steel pipes with excellent resistance to sulfuric acid dew corrosion. Its superior resistance to sulfuric acid dew point corrosion and very high cost performance is the best material that can completely replace stainless steel and surpass stainless steel (in terms of sulfuric acid dew point corrosion resistance). ND steel has great economic significance, in line with today’s high efficiency, longevity and energy saving. “Green” concepts such as environmental protection and national development policy orientation.
Advantage of 09CrCuSb (ND steel):
ND steel, 09CrCuSb steel, is the most ideal steel for “sulfuric acid resistant low temperature dew point corrosion” at home and abroad. ND steel is widely used in the manufacture of economizers, air preheaters, heat exchangers and in high sulfur flue gas. Equipment such as evaporators, used to resist corrosion of sulfur-containing flue gas dew point. ND steel also has the ability to resist chloride ion corrosion. The main reference index of ND steel pipe (soaked in 50% H2SO4 solution at 70 °C for 24 hours) is higher than that of carbon steel and stainless steel.
Application of 09CrCuSb (ND steel):
09CrCuSb seamless steel pipe is widely used in the manufacture of economizer, air heat preheater, heat exchanger, evaporator and other equipment serving in high sulfur gas, which is used to resist condensation corrosion of sulfur-containing flue gas. It is characterized by resistance to low temperature sulfuric acid dew point corrosion of flue gas below 200 ° C. It is a new clean energy-saving product.
The market price of the special sulfuric acid dew point corrosion resistant pipe for 09CrCuSb boiler heat exchanger is about 9000 yuan per ton, only 40% of the price of stainless steel pipe of the same specification. When it is used in sulfur-containing medium, its corrosion resistance is no less than that of stainless steel, and the corrosion rate is 3.481mg/cm2. H (34.81g / m2. H) in sulfuric acid solution of 70 ℃ and 50%. The corrosion resistance of ND steel (09CrCuSb) is more than 3 times that of 321 stainless steel and 7 times that of 20g. It can be seen that ND steel is the first choice material for the experimental chemical plant in the environment of sulfur-containing medium.
