Global Fastener News

SPS Announces Marine Alloy

Jason Sandefur

SPS Technologies announced a new alloy for fasteners in critical marine applications.
Working with raw material suppliers, SPS modified existing alloys for the manufactures of high-performance fasteners.
SPS engineers sought to develop a bolt exhibiting 1034 Mpa yield strength, high fracture toughness, resistance to fatigue, corrosion and hydrogen embrittlement.
SPS has developed several proprietary superalloys for high-tech fasteners. SPS engineers identified the MP159 alloy as the likely candidate for the new marine application. Metallurgy changes were necessary for the performance specifications.
The new alloy, designated as MP98T, has the same chemistry as MP159, but with different cold work and age hardening parameters. Fastener tensile strength is reduced from its aerospace level of 1792 Mpa to meet high fracture toughness requirements.
The MP 159�s strengthening mechanism is the �solid-state phase transformation of part of the matrix from a face-centered cubic crystal structure to a hexagonal close-packed structure by cold working,� according to SPS. �The reason for this transformation is the high cobalt content in the alloy, and it has been termed �the multiphase reaction.��
The new alloy may be used in aerospace because of its high fracture toughness.
For information contact Steven Buzolits, manager/product engineering, SPS. Tel: 215 572-3565 Fax 215 572-3133 E-mail: sbuzolits@spstech.com Web: spstech.com/aero \�2002 FastenerNews.com