50 grades of stainless steel

The BSSA has selected 50 Grades of Stainless Steel as its theme for 2014. Each week throughout the year, we will showcase one grade and illustrate the variety of corrosion resistant, mechanical and physical properties which determine its suitability for a wide range of applications.



6% Mo 1.4529/1.4547 N08926/S31254

Internal pumps and valves for submarines

Internal pumps and valves for submarines   

Courtesy of Stainless Steel Fasteners

Desalination plant pipework

Desalination plant pipework

Courtesy of Outokumpu Stainless

“6% Mo” is a generic term for several highly alloyed austenitic grades. They have been developed for highly aggressive seawater and chemical processing environments.

Approximate Composition – 20% Cr, 18-24% Ni, 6% Mo, 0.2% N plus Cu (Exact composition ranges vary between EN and ASTM standards).

This grade combines the following characteristics:

•    Excellent pitting and crevice corrosion resistance (PREN > 40, comparable to superduplex
•    Excellent resistance to strong acids
•    Excellent stress corrosion cracking resistance
•    Approved for use for structural components in swimming pools
•    Higher yield strength than standard austenitic stainless steels
•    Good impact toughness at sub-zero temperatures (better than superduplex)
•    Improved formability compared to superduplex
•    Careful control of welding parameters required
•    Viable alternative to expensive nickel base alloys

Applications which illustrate these features include:

Pulp and paper, desalination, chemical processing, chemical tanker ships, heat exchangers, metal refining, flue gas desulphurisation (FGD), swimming pool structural components, offshore oil and gas, submarines, aggressive food processing e.g. soy sauce, condenser tubing.

6% Mo grades are at the top end of the stainless steel “spectrum” giving excellent service in very aggressive environments.

Find out more about the 50 Grades of Stainless Steel campaign

BSSA Home  |  BSSA Membership  |  Contact Us

find us on facebookfollow us on twitter

Park Suite, Forsyth Enterprise Centre, Bramall Lane, Sheffield, S2 4SU
Tel: +44 (0)114 292 2636     Fax: +44 (0)114 292 2633     Email: admin@bssa.org.uk

If you are interested in learning more about our campaign please sign up here.
If you no longer wish to receive emails from us please unsubscribe here.

British Stainless Steel Association (BSSA): registered in England and Wales as a private company limited by guarantee; registration no. 07547349