1
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Lamberson et al. (eds.), Dynamic Behavior of Materials, Volume 1, Conference Proceedings of the Society
for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59947-8_1
Chapter 1
Mechanical Characterization of 304L- VAR Stainless Steel
in Tension with a Full Coverage from Low, Intermediate, to High
Strain Rates
Bo Song, Helena Jin, Brett Sanborn, and Wei-Yang Lu
Abstract A 304L-VAR stainless steel was mechanically characterized in tension over a full range of strain rates from low,
intermediate, to high using a variety of apparatus. While low- and high-strain-rate tests were conducted with a conventional
Instron and a Kolsky tension bar, the tensile tests at intermediate strain rates were conducted with a fast MTS and a DropHopkinson bar. The fast MTS used in this study was able to obtain reliable tensile response at the strain rates up to 150 s
−1
,
whereas the lower limit for the Drop-Hopkinson bar was determined to be 100 s
−1
. Combining the fast MTS and the DropHopkinson bar fully closed the gap within the intermediate strain rate regime. Using these four apparatus, the tensile stressstrain curves of the 304L-VAR stainless steel were obtained at various strain rates on each order in magnitude ranging from
0.0001 to 2580 s
−1
. All tensile stress- strain curves exhibited linear elasticity followed by a significant work hardening prior
to necking. After necking occurred, the specimen load decreased and the deformation became highly localized until fracture. The tensile stress-strain response the 304L-VAR stainless steel was also strain rate dependent. The flow stress increased
with increasing strain rate. The strain-rate sensitivity was also observed to be strain-dependent, possibly due to thermosoftening caused by adiabatic heating at high strain rates. The 304L-VAR stainless steel also showed a significant ductility (or
elongation to failure). The true failure strain was determined with the minimum diameter of the posttest specimen. The
results showed that the true failure strains were approximately 210% at low strain rates, but were significantly lower
(~110%) at high strain rates. The transition of true failure strain occurred within the intermediate strain rate range between
10
−2
and 10
2
s
−1
.
Keywords Intermediate strain rate · Tensile property · 304L-VAR · Strain rate effect
1.1 Introduction
Stainless steels have been of great interest to and extensively utilized in the architecture, food, medical, civil, energy, automotive, aerospace, and defense industries due to their notable corrosion resistance, recyclability, and reusability. The largest
group and the most widely used among stainless steels is 300 series, with Type 304 as the best-known grade favored for its
machinability, weldability, and formability in addition to corrosion resistance. Strain-rate-dependent mechanical response of
304 stainless steel is an important parameter in applications where the material is subjected to accidental drop, low-speed
collision, high-speed perforation, or even ultra-high-speed blast or shock loading. The investigation of mechanical properties
of 304 stainless steel with different mechanical loading conditions started in the 1970s [1, 2] and has been extensively conducted since the 1990s. In the past decades, 304 stainless steel has been mostly characterized within the quasi-static strain
rate regime with little work within intermediate- and high-strain-rate regimes, particularly for tensile tests. Recently, Cadoni
et al. [3] employed a universal electromechanical testing machine, a hydro- pneumatic apparatus, and a split Hopkinson tension bar to characterize an AISI 304 stainless steel from low, intermediate to high strain rates. Both yield and ultimate tensile
B. Song (*) · B. Sanborn
Sandia National Laboratories, Albuquerque, NM, USA
e-mail: bsong@sandia.gov; bsanbor@sandia.gov
H. Jin · W.-Y. Lu
Sandia National Laboratories, Livermore, CA, USA
e-mail: hjin@sandia.gov
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Lamberson et al. (eds.), Dynamic Behavior of Materials, Volume 1, Conference Proceedings of the Society
for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59947-8_1
Chapter 1
Mechanical Characterization of 304L- VAR Stainless Steel
in Tension with a Full Coverage from Low, Intermediate, to High
Strain Rates
Bo Song, Helena Jin, Brett Sanborn, and Wei-Yang Lu
Abstract A 304L-VAR stainless steel was mechanically characterized in tension over a full range of strain rates from low,
intermediate, to high using a variety of apparatus. While low- and high-strain-rate tests were conducted with a conventional
Instron and a Kolsky tension bar, the tensile tests at intermediate strain rates were conducted with a fast MTS and a DropHopkinson bar. The fast MTS used in this study was able to obtain reliable tensile response at the strain rates up to 150 s
−1
,
whereas the lower limit for the Drop-Hopkinson bar was determined to be 100 s
−1
. Combining the fast MTS and the DropHopkinson bar fully closed the gap within the intermediate strain rate regime. Using these four apparatus, the tensile stressstrain curves of the 304L-VAR stainless steel were obtained at various strain rates on each order in magnitude ranging from
0.0001 to 2580 s
−1
. All tensile stress- strain curves exhibited linear elasticity followed by a significant work hardening prior
to necking. After necking occurred, the specimen load decreased and the deformation became highly localized until fracture. The tensile stress-strain response the 304L-VAR stainless steel was also strain rate dependent. The flow stress increased
with increasing strain rate. The strain-rate sensitivity was also observed to be strain-dependent, possibly due to thermosoftening caused by adiabatic heating at high strain rates. The 304L-VAR stainless steel also showed a significant ductility (or
elongation to failure). The true failure strain was determined with the minimum diameter of the posttest specimen. The
results showed that the true failure strains were approximately 210% at low strain rates, but were significantly lower
(~110%) at high strain rates. The transition of true failure strain occurred within the intermediate strain rate range between
10
−2
and 10
2
s
−1
.
Keywords Intermediate strain rate · Tensile property · 304L-VAR · Strain rate effect
1.1 Introduction
Stainless steels have been of great interest to and extensively utilized in the architecture, food, medical, civil, energy, automotive, aerospace, and defense industries due to their notable corrosion resistance, recyclability, and reusability. The largest
group and the most widely used among stainless steels is 300 series, with Type 304 as the best-known grade favored for its
machinability, weldability, and formability in addition to corrosion resistance. Strain-rate-dependent mechanical response of
304 stainless steel is an important parameter in applications where the material is subjected to accidental drop, low-speed
collision, high-speed perforation, or even ultra-high-speed blast or shock loading. The investigation of mechanical properties
of 304 stainless steel with different mechanical loading conditions started in the 1970s [1, 2] and has been extensively conducted since the 1990s. In the past decades, 304 stainless steel has been mostly characterized within the quasi-static strain
rate regime with little work within intermediate- and high-strain-rate regimes, particularly for tensile tests. Recently, Cadoni
et al. [3] employed a universal electromechanical testing machine, a hydro- pneumatic apparatus, and a split Hopkinson tension bar to characterize an AISI 304 stainless steel from low, intermediate to high strain rates. Both yield and ultimate tensile
B. Song (*) · B. Sanborn
Sandia National Laboratories, Albuquerque, NM, USA
e-mail: bsong@sandia.gov; bsanbor@sandia.gov
H. Jin · W.-Y. Lu
Sandia National Laboratories, Livermore, CA, USA
e-mail: hjin@sandia.gov