Stainless International Ltd have added Special Grades to the Stainless Steel product range offered to customers.
Special applications are becoming ever more technically demanding and the new extended product portfolio aims to meet these high technical requirements.
The commercial staff at Stainless International have long experience of these special grades and applications and the extension of the range is a natural next step to support the customer base.
Special Grades can be supplied in CR or HR form on 7-10 day delivery, depending on sizes and quantities.
When considering these products please discuss your needs with us, so we can ensure availability.
High Nickel Grades
1.4539 (904L) (UNS N 08904): This grade is typically 20% Chrome and 24% Nickel. It contains Copper and Molybdenum also, which gives increased resistance to strong reducing acids, such as Sulphuric acid and stands up to Chlorides. It is suitable for applications in demanding environments such as Acid processing plants; Pulp and paper operations; equipment for seawater cooling; Oil refining and Oil rigs; and Environmental equipment. Not suitable for use above 400 deg C.
ALLOY 825 (Nicrofer 4221) (UNS N08825): A high Nickel alloy containing 19.5 – 23.5% Chrome and 38-46% Nickel with addition of Molybdenum and Copper. Excellent resistance to reducing and oxidising acids, to chloride induced stress corrosion cracking, to pitting and crevice corrosion. It has outstanding performance in seawater. Applications in Chemical processing; Pulp & Paper; Pollution control; Waste incineration; Pressure vessels and Boilers etc. Good toughness at elevated temperatures up to 550 deg C.
1.4547 (254 SMO) (UNS S31254). A ‘Super Austenitic’ grade containing 20% Chrome, 18% Nickel and 6% Molybdenum. Exhibits great resistance to chloride pitting and crevice corrosion due to >6% of Mo. High Ni content offers better resistance to stress corrosion cracking than normal 300 series and has higher strength. It has good weldability. Not suitable for use above 400 deg C.
This grade has been developed for use in seawater and other aggressive chloride bearing media: Desalination plant; Seawater handling; Heat Exchangers; Flue gas cleaning; Chemical process equipment; Bleaching equipment in pulp & paper.
Duplex and ‘Super Duplex’ Grades:
1.4462 (2205) (UNS S32205, S31803) . This is the most widely used Duplex grade of Stainless Steel, accounting for 80% of Duplex sales. 22% Chrome, 5.7% Nickel and 3.1% Molybdenum. High strength and excellent corrosion resistance, and excellent resistance to localised corrosion – interganular, pitting and crevice. However the high strength reduces machineability and makes bending and forming more difficult. Suffers from embrittlement above 300 deg C.
Used in Chemical processing, transport and storage. Oil and gas exploration and processing equipment; Flue gas cleaning; Marine and other high chloride environments; Desalination plant heat exchangers; Pulp and paper digesters; Liquor tanks and paper machines. Cargo tanks and pipe systems or chemical tankers; Bridges and components for structural design.
1.4410 (2507) (UNS S32750): 25% Chrome, 7.0% Nickel and 4.0% Molybdenum. A ‘Super Duplex’ due to higher corrosion resistance. Outstanding resistance to acids, acid chlorides, caustic solutions. Can be used in dilute hydrochloric acid. High alloy ‘Super Duplex’ steels are particularly suited to offshore applications piping, pumps, valves, heat exchangers, firewalls and blast walls on offshore platforms. For service up to 300 deg C max.
1.4501 (UNS S32760): 25% Chrome, 6.9% Nickel and 3.8% Molybdenum. Another ‘Super Duplex’ very similar to 1.4410 above. Not suitable for use above 300 deg C.
For certain applications, Duplex grades can offer a 30% weight saving compared to standard austenitic grades, due to their superior strength.
Heat resisting and high service temperature:
1.4835 (253MA) UNS S30815): 21% Chrome, 11% Nickel & microalloyed with rare earth metals. Most suitable temperature range 850 – 1100 deg C. Lower temperatures can lead to structural changes which give reduced impact resistance at room temperature. Developed for heat and creep resistance applications in Engineering; Energy conservation plants; Cement industry; Heat exchanger tubes and pipes in Exhaust systems (catalytic converters); Waste incineration; Pyrometers; Flue gas control; Furnace rolls and parts.
Stainless International Ltd invites enquiries for these Stainless Steel special grades and can discuss supply options with you to meet your needs.