Use of microstructure control to toughen ferritic steels for cryogenic use. I. Fe--Ni steels

Conference · Tue Nov 30 23:00:00 EST 1976

OSTI ID:7095126

Syn, C K; Jin, S; Morris, Jr, J W

Alternation of austenitization and austenite + ferrite two-phase decomposition treatment in a cyclic thermal treatment allows the achievement of ultra-fine grain size in steels containing 8-12% Ni. The grain refinement leads to a substantial improvement in cryogenic mechanical properties. The ductile-brittle transition temperature of a ferritic Fe-12Ni-0.25Ti alloy was suppressed to below liquid helium temperature by this grain refinement procedure; the transition temperature of commercial ''9Ni'' cryogenic steel was similarly reduced by combining the grain refinement with a final temper which introduces a small admixture of retained austenite.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7095126
• Report Number(s): LBL-5767; CONF-761085-2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CRYSTAL STRUCTURE
DUCTILE-BRITTLE TRANSITIONS
GRAIN SIZE
IRON ALLOYS
IRON BASE ALLOYS
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL STEELS
PHASE TRANSFORMATIONS
SIZE
STEELS
TITANIUM ADDITIONS
TITANIUM ALLOYS
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE