ALLOY 20 FASTENERS Specifications
Also known as Carpenter 20 and 20CB-3, Alloy 20 offers users a combination of nickel, chromium, molybdenum, and copper which provides good general corrosion resistance. Alloy 20 fasteners are best suited for mid-range corrosion use – better than steel alloys but not at the level of high performance nickel based alloys like Hastelloy C276. Alloy 20 is a nickel alloy that was specifically designed to withstand the harsh environment of hot sulfuric acid but also performs well in a variety of other acids.
Alloy 20 fasteners are an ideal choice when you don’t need the corrosion resistance power and price-tag of high performance nickel alloys like Hastelloy C276; but you need something that will give you more protection than 316 stainless steel or even a Super Duplex 2507 stainless steel.
Alloy 20 fasteners provide good performance in hot sulfuric acid, specifically they offer good resistance to stress-corrosion cracking in boiling sulfuric acid at specific range of 20% to 40% concentration, as well as general sulfuric acid resistance. Alloy 20 fasteners offer solid acid protection and will perform better than Duplex or even Monel, but for high temperature and high concentration acids, you may need to look to Inconel or Hastelloy fasteners. In addition Alloy 20 fasteners also show useful resistance to phosphoric acid and nitric acid.
- Good sulfuric acid protection at 20% – 40%
- Decent stress corrosion cracking, pitting and crevice corrosion resistance in chloride
- Resonable general corrosion protection
- Good intergranular corrosion resistance in the as-welded condition
ALLOY 20 FASTENERS
ALLOY 20 FASTENERS CHEMICAL COMPOSITION
|Ni||32 – 38|
|Mn||1 – 2|
|Cu||3 – 4|
|Cr||19 – 21|
|Mo||2 – 3|
|Nb||0.1 – 0.3|
IN WHAT APPLICATIONS IS ALLOY 20 USED?
- Synthetic rubber manufacturing equipment
- Processing of pharmaceuticals, plastics and organic and heavy chemicals
- Tanks, piping, heat exchangers, pumps, valves, and other process equipment
- Acid cleaning and pickling equipment
- Chemical process piping, reactor vessels
- Bubble caps
- Petrochemical process equipment
- Food and dye production
ALLOY 20 FASTENERS PHYSICAL & MECHANICAL PROPERTIES
|Melting Point||1443 °C (2430 °F)|
|Tensile Strength||Psi -80,000, MPa -551|
|Yield Strength (0.2%Offset)||Psi – 35,000, MPa – 241|