Project Description

Alloy 28 (UNS N08028)

Alloy 28 (UNS N08028) is a highly corrosion-resistant austenitic alloy offering resistance to a variety of media. The alloy resists attack in reducing media, due to its contents of nickel, copper and molybdenum; and resistant to oxidizing species due to its high level of chromium. Alloy 28 offers resistance to general, localized and stress-induced corrosion by chlorides and hydrogen sulfides. Thus, it is widely used in oilfield applications. Tubes are cold worked to high levels of strength for downhole service in deep sour gas wells. With its excellent combination of strength and corrosion resistance, Alloy 28 also finds applications in the process industries. It is especially useful for handling phosphoric acid. Due to its resistance to chlorides, Alloy 28 tubes may be used in the marine industry for seawater-cooled heat exchangers.

Equivalent Grades

TrademarksGBJISKSASTMUNSDINW.NrGOSTBSNF
Nicrofer3127LC
Incoloy alloy 28
Sanicro 28
00Cr27Ni31Mo3Cu
00Cr27Ni31Mo4Cu
Alloy 28N08028X1NiCrMoCu 31-27-41.4563X1NiCrMoCu 31-27-4Z1NCDU31-27-03

Product Forms

Wire, Bar, Strip, Sheet, Plate, Tube, Pipe, Pipe Fittings, Forgings

Chemical Composition,%

CPSMnSiCrNiCuMoFe
≤0.03≤0.030≤0.030≤2.50≤1.0026.0~28.030.0~34.00.6~1.43.0~4.0Bal

Typical Physical & Mechanical Properties (RT, Solution Annealed)

Density, g/cm3Melting Point, ℃Tensile Strength, MPaYield Strength, MPaElongation,%
8.001405-142550021440

Specification

Rod, Bar, Wire, ForgingsASTM B425, ASTM B564, ASME SB425, ASME SB564, ISO 9723/9724/9725, DIN 17752-17754
Plate, Sheet, StripASTM B424 ASTM B906, ASME SB424, ASME SB906, ISO 6208, DIN 17750
Pipe, TubeASTM B163, ASTM B423, ASTM B704, ASTM B705, ASTM B751, ASTM B775, ASTM B829, ASME SB163, ASME SB423, ASME SB704, ASME SB705, ASME SB751, ASME SB775, ASME SB829, ISO 6207, DIN 77751
OthersDIN 17744, ASTM B366, ASME SB366

Features

  • Very high corrosion resistance in strong acids
  • Very good resistance to stress corrosion cracking (SCC) and intergranular corrosion in various environments
  • High resistance to pitting and crevice corrosion
  • Good weldability

Application

  • Chemical processing
  • Pollution control equipment
  • Oil and gas well piping
  • Nuclear fuel reprocessing
  • Acid production
  • Pickling equipment