ASTM A182 No8020 Flange

UNS N08020

UNS N08020, also known as Alloy 20 is one of the “super” stainless steels developed for maximum resistance to acid attack, because of this, there are various uses for it in both the stainless and nickel industries. Alloy 20 seems to fall in-between both the stainless and nickel categories, as it does contain characteristics of both; however, the unified numbering system (UNS) does ultimately recognize it as a nickel based alloy, hence the UNS N08020 number.

Alloy 20 is an austenitic nickel-iron-chromium based alloy with additions of copper and molybdenum. Its nickel content aids in its chloride ion stress and corrosion resistance. The addition of copper and molybdenum provides resistance to hostile environments, pitting and crevice corrosion. Chromium adds to its resistance of oxidizing environments, such as nitric acid, and columbium (or niobium) reduces the effects of carbide precipitation. Most welding methods can be used when working with Alloy 20, except for oxyacetylene welding. It can also be hot formed using the same forces required to hot work austenitic stainless steels. In terms of machineability, outstanding finishes are possible using the same set-up and process speeds used for austenitic stainless steels, such as Stainless Steels 316 or 317.

 

Design features

 Exceptional stress-corrosion resistance in boiling 20% to 40% sulfuric acid

 Sulfuric acid general corrosion resistance

 Ideal fabricability and mechanical characteristics

 Welding produces minimal carbide precipitation

Applications

 Chemical and allied industries

 Pharmaceutical processing

 Food and dye

 Sulfur dioxide (SO2) scrubbers

 Pickling racks

 Tanks

 Severe environments

 

Product Type	Size Range	Wall/Pressure Class
Seamless Pipe	1/2” through 8”	10S, 40S (Std.), 80S (XH), 160S
Welded Pipe	3” through 12”	10S, 40S
Butt Weld Fittings	1/2” through 12”	10S, 40S (Std.), 80S (XH)
Flanges	1/2” through 12”	150, 300
Pressure Fittings	1/8” through 2”	150 lb Bar, 3000
150 lb Cast Fittings	1/2” through 2”	150
Seamless Tubing	1/8” through 1”	.035, .049, .065, .083, .095, .120
Nipples	1/4” through 2”	40S (Std.), 80S (XH)
Swages	3/8” through 4”	40S (Std.), 80S (XH)
Outlets	1/4” through 2”	10S, 40S (Std.), 80S (XH)
Valves	1/4” through 10”	150#, 300#, 1500-2000#

 

Alloy 20 Chemical Composition %

C	Cb	Cr	Cu	Mn	Mo	Ni	P	S	Si	Ta
MAX	8 Times			MAX			MAX	MAX	MAX	8 Times
0.07	Carbon-1.00	19.0-21.0	3.0-4.0	2.0	32.0-38.0	32.0-38.0	0.045	0.035	1.0	Carbon-1.00