Alloy 28: Complete Properties & Application Guide

← Back to Knowledge Center

Overview

Alloy 28 (UNS N08028 / W.Nr. 1.4563) is a high-alloy austenitic stainless steel with excellent resistance to sulfuric and phosphoric acids. The combination of nickel, chromium, molybdenum, and copper provides a cost-effective solution for chemical processing equipment handling aggressive media.

Chemical Composition

The chemical composition of Alloy 28 is carefully controlled to achieve its unique combination of properties and performance characteristics.

Element	Min %	Max %
Iron (Fe)	Balance	Balance
Nickel (Ni)	29.5	32.5
Chromium (Cr)	26.0	28.0
Molybdenum (Mo)	3.0	4.0
Copper (Cu)	0.60	1.40
Carbon (C)	—	0.02
Manganese (Mn)	—	2.0
Silicon (Si)	—	1.0

Mechanical Properties at Room Temperature

The mechanical properties of Alloy 28 vary depending on product form and heat treatment condition. The data below represents typical values for solution-annealed material.

Property	Value
Tensile Strength	580 MPa
Yield Strength (0.2% offset)	250 MPa
Elongation in 2 inches	50%
Density	8.00 g/cm3
Melting Point	1350 °C
Max Service Temperature	700 °C

Corrosion Resistance

Excellent resistance to sulfuric and phosphoric acids at various concentrations and temperatures. Good resistance to chloride pitting and crevice corrosion. Resistant to stress corrosion cracking. The copper addition enhances resistance to reducing acids.

Applications

The unique combination of properties makes Alloy 28 suitable for a wide range of demanding applications:

• Chemical Processing: Heat exchangers, piping, and vessels in sulfuric acid plants.
• Fertilizer Production: Equipment for phosphoric acid processing.
• Oil & Gas: Tubing and piping in sour gas environments.
• Pulp and Paper: Digester and bleaching equipment.
• Pollution Control: Flue gas desulfurization components.

Available Product Forms

Hangbo Alloy Group manufactures and supplies Alloy 28 in the following product forms, conforming to ASTM, AMS, and ASME specifications:

• Round Bars: Diameters from 6 mm to 300 mm, hot-finished or cold-drawn, solution annealed.
• Seamless Tubes & Pipes: Sizes from 6 mm OD to 219 mm OD, various wall thicknesses.
• Plates & Sheets: Thicknesses from 0.5 mm to 50 mm, hot-rolled or cold-rolled.
• Forgings: Custom flanges, rings, discs, and complex shapes per customer drawing.
• Welding Wire: Diameters 0.8 mm to 5.0 mm, precision-wound coils and spools.

Related Standards

Standard	Description
ASTM B704	Welded Tube
ASTM B705	Welded Pipe
ASTM B690	Seamless Pipe and Tube
ASTM B619	Welded Pipe
ASTM B366	Fittings
EN 10028-7	European Plate Standard

Contact Us for Alloy 28

Hangbo Alloy Group maintains extensive inventory of Alloy 28 in all standard product forms. We can provide mill test certificates, third-party inspection reports (SGS, TUV), and custom processing services.

For quotations, material certifications, or technical consultation, contact our sales team or call +86-136-1165-6360. We typically respond within 10 minutes.