09CrCuSb: Special Nd Steel For Low Temperature Dew Point Corrosion Resistance Of Sulfuric Acid- TJC STEEL.

​09CrCuSb -- Nd steel is a new type of low temperature dew point corrosion resistant steel with sulfuric acid which was jointly developed by Shanghai [TJC STEEL]Institute of Materials and Xingcheng Special Steel (formerly Jiangyin Steel Plant) during 1987-1990.
ND steel is a low alloy structural steel. Compared with other steels such as low carbon steel, Corten, Cr1A, etc., ND steel has excellent corrosion [TJC STEEL]resistance and mechanical properties.

Material standard
①GB 150.2-2011 "Pressure vessels -- Part 2: Materials"
②NB/T 47019-2011 "boiler, heat exchanger pipe ordering technical conditions"
③SH/T 3096-2012 "High Sour Crude Oil [TJC STEEL]Processing Equipment and Pipeline Design Material Selection Principles"

Component Specification（GB 150.2-2011）
C ≤0.12 Cr 0.70~1.10
Si 0.20~0.40 Cu 0.25~0.45
Mn 0.35~0.65 Sb 0.04~0.10
P ≤0.030 S ≤0.020

Mechanical Property
nominal thickness
(mm) strength of extension
Rm(MPa) Lower yield strength
ReL(MPa) elongation
A(%)
≤8 390~550[TJC STEEL] ≥245 ≥25

Corrosion Resistance
In the medium temperature and concentration test of sulfuric acid, Nd steel passivation due to dissolution, the surface of the steel formed a layer rich in Cu, Cr, Sb (antimony, sound: tī) and other alloy elements of the passivation [TJC STEEL]layer, and has a high sulfuric acid corrosion resistance.

▽Corrosion Rate Comparison between ND Steel and Other Steels (70℃-50%H2SO4 Solution)
type of steel corrosion rate
mg/(cm2h) multiple
ND 7.3 1
A3 103.5 14.18
Cast 63 8.63
CR1A 13.4 1.84
321 21.7 2.97
S-TEN 27.4[TJC STEEL] 3.75

For corrosion resistance, GB 150.2-2011 stipulates that corrosion resistance test shall be carried out on steel pipes. One sample shall be taken from each of two steel pipes in each batch, and each sample shall be a 10mm long pipe segment.It was soaked in H2SO4 solution with mass fraction of 50% at 70℃ (±2℃) for [TJC STEEL]24h.The average corrosion rate of the two samples is not more than 80g/m2×h or 140g/m2×h, the specific indexes are specified in the order contract.
Applications：
ND steel is the most ideal "low temperature dew point corrosion resistance of sulfuric acid" steel at home and abroad, its seamless steel pipe[TJC STEEL] is widely used in the manufacture of high sulfur flue gas service in the economizer, air preheater, heat exchanger and evaporator and other devices to resist the dew point corrosion of sulfur flue gas.