OBJECTIVES Our earlier studies have highlighted that an altered one carbon metabolism (vitamin B12, folic acid, and docosahexaenoic acid) is associated with preeclampsia. Preeclampsia is also known to be associated with oxidative stress and inflammation. The current study examines whether maternal folic acid, vitamin B12 and omega-3 fatty acid supplementation given either individually or in com...

A generalized phase transformation kinetics model is used to understand the martensite to austenite transformation in a cold-rolled and annealed metastable AISI 301LN ultrafine-grained austenitic stainless steel. The model shows that the presence of interstitial nitrogen and heavy cold-rolling is important to promote fast transformation kinetics, through rapid nitrogen-diffusion and austenite n...

We have investigated the possibility of producing a magnetic encoder by an innovative process. Instead of turning grooves in the encoder bar for precise positioning, we incorporated the information in 304L stainless steel by transforming the austenite to martensite after bar extrusion in liquid nitrogen and marking it with a laser, which caused a local transformation of martensite back into aus...

in this research, graphitization transformation of a commercial hypereutectoid steel called ck100 was studied by the dilatometric experiments at the range of 600 – 700 °c from prior martensitic structure. also the effect of quenching media on the initial graphitization time and completion of transformation has been discussed. also, graphitization transition from the different prior microstructu...

The influence of the free surface on martensitic transformation was examined by comparing the highest temperature at which martensite forms (MS), as measured using dilatometry, with surface–observations using confocal laser scanning microscopy. It is found that the proximity of the surface during confocal microscopy permits martensitic transformation to occur at a higher temperature, with a red...

The Ginzburg-Landau theory for multivariant martensitic phase transformations is advanced in three directions: the potential is developed that introduces the surface tension at interfaces; a mixed term in gradient energy is introduced to control the martensite-martensite interface energy independent of that for austenite-martensite; and a noncontradictory expression for variable surface energy ...

A series of medium-carbon low alloy steels was quenched to martensite and tempered at 150 C. This low-temperature-tempered (LTT) martensite was subjected to uniaxial tensile and impact testing. Yield and ultimate tensile strength and uniform elongation increased, and post uniform and total elongation and fracture toughness decreased, with increasing carbon concentration. The carbon dependence o...

Besides permitting an accurate determination of the ferromagnetic-to-paramagnetic phase transition temperature and the characteristic temperatures for the beginning and end of the growth of martensite (austenite) phase at the expense of austenite (martensite) phase while cooling (heating), the results of an extensive ac susceptibility, sound velocity and internal friction investigation of the t...

The shape memory effect (SMA) relies on martensitic transformations which are macroscopically due to a pseudo-shearing deformation, resulting from a deformation mode similar to slip or twinning in ordinary metals and alloys under stress. However, since martensitic thermoelastic transformations are reversible, the deformation behaviour of alloys that undergo this type of transformations is remar...

This study investigated the microstructures of pearlite and martensite transformed from ultrafine-grained austenite in 0.45C steel and Vadded 0.45C steel. The mean prior austenite grain sizes were refined to be 4.5 μm in the 0.45C specimen and 2.4 μm in the V-added 0.45C specimen through cyclic heat treatment of austenitizing and water quenching, i.e., repetition of martensite § austenite trans...