Strain Rate Effect on Tensile Behavior for a High Specific Strength Steel: From Quasi-Static to Intermediate Strain Rates

Abstract

Abstract:The strain rate effect on the tensile behaviors of a high specific strength steel (HSSS) with dual-phase microstructure has been investigated. The yield strength, the ultimate strength and the tensile toughness were all observed to increase with increasing strain rates at the range of 0.0006 to 56/s, rendering this HSSS as an excellent candidate for an energy absorber in the automobile industry, since vehicle crushing often happens at intermediate strain rates. Back stress hardening has been found to play an important role for this HSSS due to load transfer and strain partitioning between two phases, and a higher strain rate could cause even higher strain partitioning in the softer austenite grains, delaying the deformation instability. Deformation twins are observed in the austenite grains at all strain rates to facilitate the uniform tensile deformation. The B2 phase (FeAl intermetallic compound) is less deformable at higher strain rates, resulting in easier brittle fracture in B2 particles, smaller dimple size and a higher density of phase interfaces in final fracture surfaces. Thus, more energy need be consumed during the final fracture for the experiments conducted at higher strain rates, resulting in better tensile toughness.

Precipitation behavior of dispersoids and elevated-temperature properties in Al–Si–Mg foundry alloy with Mo addition

“…9 c-d), exhibiting the ductile tensile behavior. The formation of dimples is the result of the void nucleation and subsequent coalescence during tensile deformation [38,39]. Compared Fig.…”

Deformation Behavior of the Alloys under Simple and Combined Loading Conditions at Various Deformation Rate

“…In total, eight articles [1][2][3][4][5][6][7][8] have been presented in the present Special Issue. Their target metals are broad, ranging from an advanced steel [1] to alloys composed of light metals such as magnesium [2], titanium [3], and aluminum [3][4][5][6], as well as alloys of a smart Ni-Ti system with a shape memory effect [7] and depleted uranium [8]. Almost all target metals are commonly used in industry.…”

“…The following four experimental works [1,2,4,8] discuss from metallurgical points of view. The microstructural studies are done as well by using TEM, Electron Back Scatter Diffraction (EBSD), or Energy Dispersive Spectroscopy (EDS).…”

“…The microstructural studies are done as well by using TEM, Electron Back Scatter Diffraction (EBSD), or Energy Dispersive Spectroscopy (EDS). Wang et al [1] studies the strain rate effect on the tensile behaviors of a high-specific-strength steel (HSSS) with dual-phase microstructure. Major tensile properties show the positive sensitivity with respect to the strain rate ranging from 10 −4 to 10 s −1 .…”

Impact Load Effects on Post-Installed Anchors: An Experimental Investigation

“…This phenomenon has been adequately studied and confirmed by researchers including Malvar and Crawford [23], [24], who conducted extensive literature review on the subject to characterize the compressive and tensile strength of concrete and the strength of steel reinforcement (yield and ultimate) at high rates of loading. For High Specific Strength Steel (HSSS), Wei et al [68] observed that both the yield stress and ultimate stress increase with increasing strain rate as testing was carried out at rates ranging from 0.0006 /s to 56 /s. In investigating the effects of strain rate on yield stress of three structural steel types ( ASTM A36, ASTM A441 and Quenched and Tempered (Q-T)) Nagaraja et al [69] observed that though the ratio of the dynamic yield to static yield stress increased with increasing loading rates, the degree of increase was lower as the yield strength of the steel increased.…”