Effect of Delamination and Grain Refinement on Fracture Energy of Ultrafine-Grained Steel Determined Using an Instrumented Charpy Impact Test.

Improving the balance of strength and toughness in structural materials is an ongoing challenge. Delamination and grain refinement are some of the methods used to do this. In this paper, two different steels, 0.

Dynamic balance ability in single-leg drop jump landing in junior female athletes after shin splints-assessment from a preventive perspective.

[Purpose] To develop assessment/rehabilitation indices for prevention of chronic and recurrent shin splint injuries among sport athletes, we analyzed the plantar center of pressure trajectories after drop-jump landing on one leg, and compared the foot function on the injured and healthy sides. [Participants and Methods] The participants were 10 female athletes who received consultation at our facility due to shin splints of the lower leg. The exercise task was the "single-leg drop jump landing test", in which the participants maintained a static posture on one leg for 8 s after landing.

Plastic Instability in Medium-Carbon Tempered Martensite Steel.

Inhomogeneous plastic deformation damages the surface quality of a product in the metal forming process. Therefore, it is necessary to investigate the plastic instability of a metal. Tempered martensite is a common microstructure of medium-carbon steel.

Grain-to-Grain Interaction Effect in Polycrystalline Plain Low-Carbon Steel within Elastic Deformation Region.

A grain is surrounded by grains with different crystal orientations in polycrystalline plain low-carbon steel. The grain is constrained by its adjacent grains in the tension process. The interaction of the grain with the adjacent grains was investigated within the elastic deformation region.

Ductile-to-Brittle Transition and Brittle Fracture Stress of Ultrafine-Grained Low-Carbon Steel.

Ductile-to-brittle transition (DBT) temperature and brittle fracture stress, , are important toughness criteria for structural materials. In this paper, low-carbon steels with an ultrafine elongated grain (UFEG) structure (transverse grain size 1.2 μm) and with two ferrite ()-pearlite structure with grain sizes 10 µm and 18 µm were prepared.

[Radiofrequency ablation therapy combined with hepatectomy for liver metastasis of colorectal cancer].

Radiofrequency ablation (RFA) therapy combined with hepatectomy was performed in 5 patients with synchronous liver metastases of colorectal cancer. RFA of liver metastases was performed using a Cool-tip electrode (Radionics; Burlington, MA, USA). The ablation time used in each session varied according to the tumor size and intraoperative impedance.

Shape effect of ultrafine-grained structure on static fracture toughness in low-alloy steel.

A 0.4C-2Si-1Cr-1Mo steel with an ultrafine elongated grain (UFEG) structure and an ultrafine equiaxed grain (UFG) structure was fabricated by multipass caliber rolling at 773 K and subsequent annealing at 973 K. A static three-point bending test was conducted at ambient temperature and at 77 K.

Hydrogen embrittlement property of a 1700-MPa-class ultrahigh-strength tempered martensitic steel.

The hydrogen embrittlement property of a prototype 1700-MPa-class ultrahigh-strength steel (NIMS17) containing hydrogen traps was evaluated using a slow strain rate test (SSRT) after cathodic hydrogen precharging, cyclic corrosion test (CCT) and atmospheric exposure. The hydrogen content in a fractured specimen was measured after SSRT by thermal desorption spectroscopy (TDS). The relationship between fracture stress and hydrogen content for the hydrogen-precharged specimens showed that the fracture stress of NIMS17 steel was higher, at a given hydrogen content, than that of conventional AISI 4135 steels with tensile strengths of 1300 and 1500 MPa.

Inverse temperature dependence of toughness in an ultrafine grain-structure steel.

Materials are typically ductile at higher temperatures and become brittle at lower temperatures. In contrast to the typical ductile-to-brittle transition behavior of body-centered cubic (bcc) steels, we observed an inverse temperature dependence of toughness in an ultrahigh-strength bcc steel with an ultrafine elongated ferrite grain structure that was processed by a thermomechanical treatment without the addition of a large amount of an alloying element. The enhanced toughness is attributed to a delamination that was a result of crack branching on the aligned {100} cleavage planes in the bundles of the ultrafine elongated ferrite grains strengthened by nanometer-sized carbides.