dual phase steels with different martensite volume fraction and morphology were tensile tested at a temperature range of 25 to 5500c. stress-strain curves of all steels showed serration flow at temperatures of 250 and 3500c, and smooth flow at the other temperatures. both yield and ultimate tensile strengths increased with increasing testing temperature up to about 4500c and then decreased at h...

Dual phase steels with different martensite volume fraction and morphology were tensile tested at a temperature range of 25 to 5500C. Stress-strain curves of all steels showed serration flow at temperatures of 250 and 3500C, and smooth flow at the other temperatures. Both yield and ultimate tensile strengths increased with increasing testing temperature up to about 450<sup...

The effect of microstructural refinement and intercritical annealing on the mechanical properties and work-hardening response of a low carbon St12 steel was studied. It was revealed that intercritical annealing of the ferritic-pearlitic sheet results in the formation of a coarse-grained DP microstructure with discrete martensite islands normally formed in place of pearlitic colonies, which resu...

The austenite-to-martensite transformation in a partially hardened stainless steel containing 17wt %Cr, 7wt %Ni and 1wt % Al was investigated with Vibrating Sample Magnetometry and Electron Back-Scatter Diffraction. Magnetometry demonstrated that measurable martensite formation can be suppressed on fast cooling to 77K as well as on subsequent fast heating to 373 K. Surprisingly, martensite form...

The austenite-to-martensite transformation in a partially hardened stainless steel containing 17wt %Cr, 7wt %Ni and 1wt % Al was investigated with Vibrating Sample Magnetometry and Electron Back-Scatter Diffraction. Magnetometry demonstrated that measurable martensite formation can be suppressed on fast cooling to 77K as well as on subsequent fast heating to 373 K. Surprisingly, martensite form...

The fct martensite morphology and the martensite transformation temperatures are examined for Pd-rich Fe–Pd–Pt alloys, which have the composition of Fe–(xPdyPt)xþy1⁄430 at:%. The replacement of Pd with Pt content causes solution hardening. The shape memory effects are investigated below the Af temperatures. Above the Af temperatures, the stress induced martensite in several grains completely di...

Purpose: The aim of the paper is to design heat treatment conditions of dual-phase steel and to determine their influence on the structure and mechanical properties of steel. Design/methodology/approach: The heat treatment of the C-Mn steel in order to obtain a dual-phase ferritic – martensitic structure of desirable phase fractions was realized. To investigate the influence of heat treatment p...

Magnetic Shape-Memory (MSM) materials are a new category of actuator materials with the potential to produce both large actuator strain and rapid response. To explore the possibility of developing MSM materials based on Fe-Ni-Co-Ti alloys, the effects of chemical composition (Co/Ni ratio) and ausaging on microstructure and magnetic shapememory response were studied. A suitable choice of chemica...

Article history: Received 29.05.2012. Received in revised form 27.07.2012 Accepted 03.09.2012. The influence of sub-temperature quenching temperature on the tensile strength, hardness and toughness of 60Si2Mn steel has been studied, and the ferrite content, austenite grain size and martensite morphology of the microstructure of this steel after sub-temperature quenching analyzed. The results sh...

Nanoindentation measurements were obtained on eight commercially-produced DP980 dual-phase steels to quantify the hardness of the individual constituents, ferrite and martensite, in each steel. Each microstructure was also evaluated to determine grain size, martensite volume fraction (MVF), and retained austenite content. Nanoindentation hardnesses and quantitative microstructural measurements ...