Details

Autor(en) / Beteiligte

• Jo, Min Cheol
• Kim, Selim
• Kim, Dae Woong
• Park, Hyung Keun
• Hong, Sung Suk
• Kim, Hong Kyu
• Kim, Hyoung Seop
• Sohn, Seok Su
• Lee, Sunghak

Titel

Understanding of adiabatic shear band evolution during high-strain-rate deformation in high-strength armor steel

Ist Teil von

• Journal of alloys and compounds, 2020-12, Vol.845, p.155540, Article 155540

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The microstructural evolution and formation mechanism of adiabatic shear band (ASB) in a high-strength armor steel were investigated using a laboratory-scale split Hopkinson pressure bar, and the results were correlated with the actual ballistic impact behavior. The interrupted dynamic compressive test results reveal that a deformed ASB (dASB) starts to form right after the stress collapse and it develops into a transformed ASB (tASB). In the ballistic impact, wide tASBs form mostly at the perforated surface, and narrower tASBs are branched from the tASB. Very fine equiaxed grains of ∼190 nm in the tASB developed during the dynamic compression indicates that the dynamic recrystallization occurs even in 86.5 μs, and then the grains grow up to 260 nm in 9.5 μs. Rotational dynamic recrystallization mechanism and grain-growth rate model were proposed based on the calculation of temperature rise from a thermo-elasto-plastic finite element method, which provide a reasonable explanation for the formation and growth of fine equiaxed grains during both the dynamic compression and ballistic impact. A linkage of equiaxed subgrains and elongated parent subgrains demonstrates that the equiaxed subgrains did not evolve from nucleation and growth processes but from the sub-boundary rotation. Based on the underlying formation mechanisms and kinetics of ASBs, this study would suggest a reliable method to interpret the ASB formation and associated fracture mechanism during the ballistic impact. [Display omitted] •The microstructural evolution of ASB in an armor steel was investigated.•The dynamic compression result was correlated with the ballistic impact behavior.•The equiaxed grains in ASB are formed by sub-boundary rotation of ∼30°.•The growth of equiaxed grains within ASB was observed.•The RDR mechanism and grain-growth-rate model were proposed.