Deformation and failure mechanism in AISI 4340 steel under ballistic impact

Deformation and failure mechanism in quench-hardened AISI 4340 steel under ballistic impact is investigated. The influence of microstructure on damage evolution is also evaluated. Strain localization and shear failure along adiabatic shear bands are the dominant deformation and failure mechanisms. The time and critical strain for the commencement of strain localization is influenced by strain rate and microstructure. The microstructure of the steel sample also influenced the type of adiabatic shear bands formed during impact. Failure mechanism involves nucleation of micro-voids, which clusters to form bigger pores. Extremely fine micro-cracks are initiated adjacent to the pores and in shear flow direction along the shear bands. These micro-cracks become interconnected and grow to macro-cracks, which cause fracture of some of the investigated cylindrical steel samples under impact. The susceptibility of the adiabatic shear bands to cracking increases with decreasing tempering temperature of the steel.

[1]  S. E. Schoenfeld,et al.  A failure criterion based on material instability , 2003 .

[2]  M. Meyers,et al.  High-strain-rate deformation of granular silicon carbide , 1998 .

[3]  M. Meyers.  Dynamic failure : mechanical and microstructural aspects , 1994 .

[4]  M. Bassim,et al.  Characterization of the compression properties of rail steels at high temperatures and strain rates , 1991 .

[5]  M. Bassim.  Study of the formation of adiabatic shear bands in steels , 2001 .

[6]  M. N. Raftenberg,et al.  Metallographic observations of armor steel specimens from plates perforated by shaped charge jets , 1999 .

[7]  Z. H. Chen,et al.  An investigation on the formation and propagation of shear band in fine-blanking process , 2003 .

[8]  W. C. Leslie,et al.  The nature of “white streaks” in impacted steel armor plate , 1971 .

[9]  A. Molinari,et al.  Analysis of the dynamic propagation of adiabatic shear bands , 2002 .

[10]  M. Meyers,et al.  High-strain-rate deformation and comminution of silicon carbide , 1998 .

[11]  J. W. Walter,et al.  On stress collapse in adiabatic shear bands , 1987 .

[12]  M. Meyers,et al.  SHEAR LOCALIZATION IN HIGH-STRAIN-RATE DEFORMATION OF GRANULAR ALUMINA , 1996 .

[13]  H. Rogers.  Adiabatic Plastic Deformation , 1979 .

[14]  J. Derep.  Microstructure transformation induced by adiabatic shearing in armour steel , 1987 .

[15]  M. Meyers,et al.  Self-organization of shear bands in titanium and Ti–6Al–4V alloy , 2002 .

[16]  Marc A. Meyers,et al.  Shear localization in dynamic deformation of materials: microstructural evolution and self-organization , 2001 .

[17]  Gerry Byrne,et al.  TEM study on the surface white layer in two turned hardened steels , 2002 .

[18]  M. Bassim,et al.  High strain rate effects on the strain of alloy steels , 1999 .

[19]  W. Proud,et al.  High-speed photographic study of the drop-weight impact response of RDX/DOS mixtures , 2003 .

[20]  S. Ahzi,et al.  Influence of the material constitutive models on the adiabatic shear band spacing: MTS, power law and Johnson¿Cook models , 2004 .

[21]  A. Zurek.  The study of adiabatic shear band instability in a pearlitic 4340 steel using a dynamic punch test , 1994 .

[22]  J. Duffy,et al.  An experimental study of the formation process of adiabatic shear bands in a structural steel , 1988 .

[23]  Marc A. Meyers,et al.  Observation of an adiabatic shear band in AISI 4340 steel by high-voltage transmission electron microscopy , 1990 .