The effect of ferrite grain size on the fatigue and tensile properties of dual phase steels with a 0.25 volume fraction of martensite (Vm) under different heat treatments was investigated. The heat treatments were homogenized at 1200 oC along with several subsequent normalizations at 910 oC, resulting in different microstructures and mechanical properties. After heat treatment, the obtained ste...

Magnetic field processing is a new promising tool for the structural and functional control of materials. A significant potential exists for tailoring microstructures and impacting kinetics of phase transformation in steels. A high magnetic field modifies the Gibbs free energy. As a result, the phase diagram is shifted upwards so that the Ac1 and Ac3 temperatures increase as the magnetic field ...

The mechanical properties of the high-strength low-alloy pipeline steels were mainly controlled by the subsequent phase transformations after rolling. The influence of hot uniaxial compression on the phase transformation of acicular ferrite was explored by viewing of the deformation degree, the deformation temperature, and the strain rate. The results show that the increase of deformation amoun...

Hot–press forming steels are formed in a fully austenitic state followed by die– quenching in order to generate martensite and achieve a strong steel. The ductility however, tends to be limited. We explore in this work a novel steel design in which the forming operation is in the two–phase austenite and ferrite field, so that the quenching results in a dual–phase ferrite and martensite microstr...

Cobalt ferrite is a ferrimagnetic magnetostrictive ceramic that has potential application in magnetoelastic and magnetoelectric transducers. In this work, CoFe(2)O(4) was obtained using a conventional ceramic method and Bi(2)O(3) was used as additive in order to obtain liquid-phase sintered samples. Bi(2)O(3) was added to the ferrite in amounts ranging from 0.25 mol% to 0.45 mol% and samples we...

The main goal of this study was to develop a new processing technology for a high-strength low-alloy (HSLA) steel in order to maximize the mechanical properties attainable at its low alloy levels. Samples of the steel were processed using thermal deformation schedules carried out in single-phase (γ) and dual-phase (γ + α) regions. The samples were rolled at unconventional finishing temperatures...

in many cases, a torsional shaft may be a thick-walled radially inhomogeneous cylindrical object. the hollow shafts made of functionally graded materials (fgms) are such kind of compositions which were studied in this paper. cylindrical fg shafts are composed of ceramic and metallic parts with power function distribution across the radial direction. the ceramic phase is isotropic elastic and th...

Cobalt-ferrite (CoFe2O4) based materials are suitable candidates for magnetomechanical sensor applications owing to a strong sensitivity of their magnetostriction to an applied magnetic field. Zn-doped cobalt-ferrites, with nominal compositions CoFe2−xZnxO4 (x = 0–0.3), were synthesized by auto-combustion technique using Co, Fe, and Znnitrate as precursors. X-ray spectra analysis and Transmissi...

To support quantitative design of ultra-high-strength (UHS) secondary-hardening steels, the precipitation of cementite prior to the precipitation of the M2C phase is investigated using a model alloy. The microstructure of cementite is investigated by transmission electron microscopy (TEM) techniques. Consistent with earlier studies on tempering of Fe-C martensite, lattice imaging of cementite s...