Advanced Corrosion Resistant Nickel-Alloys for Marine Applications, Including Cryogenic Service

摘要

HASTELLOY? alloys C-86 and C-22HS are currently being used or evaluated by the Navy bolting applications where both high strength, toughness, ductility, resistance to corrosion and hydrogen embrittlement are required. Alloys C-86 and C-22HS have been used in severe applications that require both corrosion resistance and high strength and C-22HS has properties applicable to cryogenic service. Alloy C-22HS is included in NACE MR0175/ISO 15156 exhibiting resistance to extremely severe corrosive environments. Properties of these alloys relevant to marine corrosion and Navy fastener applications are presented. The alloy C-22HS yield strength ranges from 191 to 205 ksi (1317 to 1413 MPa). Alloy C-22HS also exhibits excellent ductility and fracture toughness of ≥150 ft-lbs (≥203 J) from -300oF to +550oF (-149 to 288°C). Superior corrosion resistance, high yield strength, low magnetic permeability and outstanding cryogenic properties define C-22HS alloy usefulness. NITRONIC? 50HS (UNS S20910) Stainless Steel provides a combination of corrosion resistance and strength not found in any other commercial material available in its price range. As a result, the use of this alloy for boat shafting is significantly increasing for commercial and naval shipping. NITRONIC 50HS is currently used by the USCG for shafting on the Fast Response Cutter.