Introduction

Alloy 20, also known as Carpenter 20,  is a nickel-iron-chromium austenitic alloy that was developed for maximum  resistance to acid attack, specifically sulfuric acid. This superalloy has  excellent resistance to general corrosion, pitting, and crevice corrosion in  chemicals containing chlorides and sulfuric, phosphoric, and nitric acids. It  also contains niobium for stabilization against sensitization and resultant  intergranular corrosion. Carpenter 20 combines excellent corrosion resistance  with elevated mechanical properties and relatively easy fabrication. Although  originally designed for use in sulfuric acid related industries, Alloy 20 is  now a popular choice for a wide variety of industries including the chemical,  food, pharmaceutical, and plastics industries. In addition, this superalloy  is used in heat exchangers, mixing tanks, metal cleaning and pickling  equipment, and piping.

There has long been a debate on  whether Carpenter 20 is a stainless steel or a nickel alloy because the  nickel content is right on the border of defining it as one way or the other.  So, depending on who you talk to this alloy may be referred to as alloy 20  Stainless Steel or as a nickel alloy. Either way it is still great for  corrosion resistance.

Character

l    Excellent general corrosion resistance to sulfuric acid

l    Excellent resistance to chloride stress corrosion  cracking

l    Excellent mechanical properties and fabricability

l    Minimal carbide precipitation during welding

l    Excels in resisting corrosion to hot sulfuric acids

Application

l    Excellent general corrosion resistance to sulfuric acid

l    Excellent resistance to chloride stress corrosion  cracking

l    Excellent mechanical properties and fabricability

l    Minimal carbide precipitation during welding

l    Excels in resisting corrosion to hot sulfuric acids

Equal grades

Alloy20，UNS N08020，Carpenter  20Cb-3，NS143，0Cr20Ni35Mo3Cu3Nb

Chemical composition

Ni=32.00~38.00，Cr=19.0~21.0，Cu=3.0~4.0，Mo=2.0~3.0，Nb=8xC≤1.0，C≤0.07，Mn≤2.0，P≤0.045，S≤0.035， Si≤1.0，Fe=remainder

Standards

ASTM B729

ASTM B464

ASTM B468

ASTM B463

ASTM B473

ASTM B462

ASTM B366

Forms available  at A-one Alloy

Plate, pipe, strip, tube, bar,  forging.

Delivery

EU & US origin plate in stock. For  delivery of other products please contact A-one Alloy for confirmation.