Comparison of residual microstructures for 304 stainless steel shock loaded in plane and cylindrical geometries: implications for dynamic compaction and forming

Journal Article · Mon Apr 01 00:00:00 EST 1985 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(85)90031-8· OSTI ID:5163290

Johnson, K A; Murr, L E; Staudhammer, K P

Utilizing a cylindrically symmetric explosive geometry capable of producing definable pressure regimes ranging from about 20-120 GPa (1.2 Mbar) in 304 stainless steel rounds, residual ..cap alpha..'martensite volume fractions exceeding 70% were measured and compared with volume fractions not exceeding 8% over the same pressure range for plane-wave shock compression. Observations by transmission electron microscopy showed the ..cap alpha..'-martensite to be strain-induced. The implications of these results are that the cylindrical explosive loading involves a triaxial strain state which is conducive to the production of strain induced ..cap alpha..'-martensite; and that interpolations or extrapolations for optimizing powder compaction or other forming processes based upon planar shock geometries or gun fired projectile compaction experiments must be carefully considered, especially if ..cap alpha..'-martensite can be formed. The fact that high volume fractions of ..cap alpha..'-martensite can be produced in shock deformed type 304 stainless steel fo complex strain states could explain high-rate forming performance differences such as cracking and extrusion difficulties. These results are indicative of the extremely rapid production of high volume fractions of ..cap alpha..'-martensite even after very small strain in dynamic (shock) extrusion.

• Research Organization: Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM
• OSTI ID: 5163290
• Journal Information: Acta Metall.; (United States), Vol. 33:4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
STAINLESS STEEL-304
COMPACTING
EXTRUSION
MICROSTRUCTURE
PRESSURE EFFECTS
COMPRESSION
CRACK PROPAGATION
CRYSTAL-PHASE TRANSFORMATIONS
GEOMETRY
IMPACT SHOCK
MARTENSITE
PERFORMANCE
POWDERS
SHOCK WAVES
STRAINS
TRANSMISSION ELECTRON MICROSCOPY
ALLOYS
CARBON ADDITIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION RESISTANT ALLOYS
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
FABRICATION
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
MATERIALS WORKING
MATHEMATICS
MICROSCOPY
NICKEL ALLOYS
PHASE TRANSFORMATIONS
STAINLESS STEELS
STEELS
360101* - Metals & Alloys- Preparation & Fabrication
360102 - Metals & Alloys- Structure & Phase Studies