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

Trademarks	GB	JIS	KS	ASTM	UNS	DIN	W.Nr	GOST	BS	NF
Nicrofer3127LC Incoloy alloy 28 Sanicro 28	00Cr27Ni31Mo3Cu 00Cr27Ni31Mo4Cu	–	–	Alloy 28	N08028	X1NiCrMoCu 31-27-4	1.4563		X1NiCrMoCu 31-27-4	Z1NCDU31-27-03

Product Forms

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

Chemical Composition,%

C	P	S	Mn	Si	Cr	Ni	Cu	Mo	Fe
≤0.03	≤0.030	≤0.030	≤2.50	≤1.00	26.0~28.0	30.0~34.0	0.6~1.4	3.0~4.0	Bal

Typical Physical & Mechanical Properties (RT, Solution Annealed)

Density, g/cm3	Melting Point, ℃	Tensile Strength, MPa	Yield Strength, MPa	Elongation,%
8.00	1405-1425	500	214	40

Specification

Rod, Bar, Wire, Forgings	ASTM B425, ASTM B564, ASME SB425, ASME SB564, ISO 9723/9724/9725, DIN 17752-17754
Plate, Sheet, Strip	ASTM B424 ASTM B906, ASME SB424, ASME SB906, ISO 6208, DIN 17750
Pipe, Tube	ASTM 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
Others	DIN 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