ASTM B464 B468 B729 Nickel Alloy Pipe Alloy 20 Seamless Welded Oil Rusted Surface

ASTM B464 B468 B729 Alloy 20 seamless welded nickel alloy pipe

1. Alloy 20 nickel alloy pipe material 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. Thissuperalloy 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.

What are the characteristics of Alloy 20?
• Excellent general corrosion resistance to sulfuric acid
• Excellent resistance to chloride stress corrosion cracking
• Excellent mechanical properties and fabricability
• Minimal carbide precipitation during welding
• Excels in resisting corrosion to hot sulfuric acids

Chemical Composition, %

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

ASTM Specifications

Mechanical Properties
Annealed Material

2. In what forms is Alloy 20 Available?
• Sheet
• Plate
• Bar
• Pipe & Tube (welded & seamless)
• Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)
• Wire

3. The surface for Alloy 20 nickel alloy pipe

Polish

Pickling

#3 Finish
Grain finish. Also called Grinding, Roughing or Rough Grinding Very coarse finish. The material is polished to a uniform finish between 60 and 180 grit.

#4 Architectural Finish
Also called Brushed, Directional or Satin Finish. A #4 Architectural Finish is characterized by fine polishing grit lines that are uniform and directional in appearance. It is produced by polishing the metal with a 120 - 180 grit belt or wheel finish and then softened with an 80 - 120 grit greaseless compound or a medium non woven abrasive belt or pad.

#4 Dairy or Sanitary Finish
This finish is commonly used for the medical and food industry - almost exclusively used on stainless steel. Great care should be taken in removing the surface defects in the metal - like pits - that could allow bacteria to grow. This finish is produced by polishing with a 180 - 240 grit belt or wheel finish softened with 120 - 240 grit greaseless compound or a fine non woven abrasive belt or pad.

#6 Finish
Buffed finish. Some light grain. Some haze. This finish is produced by polishing with a 220 - 280 grit belt then buffed with a sisal to create a uniform buffed finish.

#7 Finish
Smooth buffed finish with a very bright appearance. Very light haze. The part is belt polished with a 280 - 320 belt then buffed with a cut and color compound. This is a common finish in preparation for chrome plating. A #7 finish can be made bright by color buffing with coloring compound and a cotton buff. This is a good way to keep polishing costs down when a part needs to be shiny but not flawless.

#8 Mirror Finish
"Mirror" bright finish with clear reflection - No haze. All surface defects are removed. The part is buffed and then color buffed to achieve a mirror finish. The quality of this finish is dependent on the quality of the metal being polished. Castings that have pits will be difficult - if not impossible polish to a #8.

4. Alloy 20 pipe MTC we exported to India for your reference