Stress-induced martensitic transformations are clarified in classes of NiMnGa alloys which undergo the stress-free, thermal-induced inter-martensite transformation austenite (A) pre-martensite (PM) martensite. This study implements a comprehensive experimental approach, including analysis of the strain–temperature and stress–strain response, which discloses stress-induced inter-martensite trans...

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...

in this study, the effects cold rolling and annealing parameters during thermomechanical processing of the aisi 201ln stainless steel were investigated. the cast samples were homogenized, hot-rolled and solution-annealed to acquire a suitable microstructure for the subsequent thermomechanical treatment. unidirectional and transverse multi-pass cold rolling at 25, 0 and -15 °c was carried out to...

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 ...

Strain-induced phase transformation and damage accumulation in austenitic stainless steel subjected to cyclic loading were investigated by nondestructive evaluation. The cyclic loading test was performed at various strain amplitudes at the same strain rate. The volume fraction of the strain-induced phase transformation (α′-martensite) was determined by ferrite scope and magnetic coercivity meas...

Stabilization of martensite and two way shape memory effect (TWSME) was studied in Cu-Ai-Mn alloys containing 9.7-11.8 wt% Al, and 3.0-9.25 wt% Mn, which were quenched to various temperatures. The transforming temperatures were in the range -70 to +220°C. The majority of alloys quenched directly to martensite did not show reverse transformation on heating due to stabilization and further temper...

Martensitic and bainitic steels are two types of widely used steels with excellent mechanical behaviors in automatic industry. It’s universally acknowledged that asquenched martensite possesses poor ductility and impact toughness, which should be tempered before putting into application. During tempering, as-quenched martensite changes from a hard and brittle microstructure to more ductile and ...

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...

Transmission electron microscopy was performed to investigate the microstructure and precipitates in the annealed Co38Ni33Al29 ferromagnetic shape memory alloy. Apart from the dendritic secondary phase in the austenite matrix, micron-sized (up to 100 lm) fcc-based precipitates with partial c0 L12 ordering and containing none, one or three {111}p parallel twin planes were found. The orientation ...