The Hastelloy C-276 plates/ sheets are generally manufactured in accordance with ASTM B575 or ASME SB-575 Grade UNS N10276. When used in flue gas desulfurization systems, the alloy C-276 plates are usually lined or cladded to the internal surface of the absorption tower. In the thermal power plant FGD system, boiler exhaust gas finally enters the chimney to discharge smoke after cleaning, defogging and heat exchanging. Due to large temperature differences, mechanical vibration and fast gas velocity, the joint of flue and absorber become the most severe corrosion area. Hastelloy C276 plates/sheets have good corrosion resistance and high-temperature resistance, so it is widely used as an anti-corrosion lining material in the FGD absorption tower entrance chimney.

Chemical Composition Requirements

Chemical composition for Hastelloy C-276 plates/sheets for FGD system, %
Mo	15.0-17.0
Cr	14.5–16.5
Fe	4.0–7.0
W	3.0–4.5
Co	2.5
C	0.010
Si	0.08
Mn	1.0
V	0.35
S	0.04
P	0.03
Ni	Remainder

Mechanical Properties

Tensile Strength,min.	Yield Strength,min.	Elongation,min.	Hardness Brinell, max
Mpa	Mpa	%	HB
690	283	400	100

Welding

The P-No for welding of UNS N10276 is 43. The welding of Hastelloy C-276 materials is always required during the construction of the scrubber column of an FGD system. It may include the welding between two alloy C-276 plates or carbon steel + alloy C-276 clad metals. The former can be achieved by gas tungsten arc welding(GTAW) process, and the latter can be done by the shielded metal arc welding(SMAW) process.