Calculations verify that carbon diffusion may occur during the lath martensite fomtion. Accordingly,the diffusion of int2rstitial ator ions must be taka into account nhfn martmitic transformtion is defined as a diffusionless transformation. In derivation of the kinetics equation of the ath& martensitic transfomtion,rzgardng the c a r h diffusion, i .e.the enrichment of the austenite during the ...

A dual-phase steel chemistry has been processed with varying intercritical annealing temperatures and the properties investigated. It was found that increasing temperature in region led to an increase volume fraction (52%–65%) grain size (1.8–3.3 µm) of martensite whilst ferrite decreased. The highest tensile strengths were at low temperatures, achieving 935 MPa elongation values 21% achieved t...

introduction: the effects of different doses of oestrogen on the endometrium of women with premature ovarian failure have been examined in this study. materials and methods: four groups of women of reproductive age were studied; 1 normal fertile controls 2. patients given a standard, variable hormone replacement therapy (hrt) 3. a group given a fixed daily dose of 1 mg of oestrogen and 4. a gro...

The focus of this study was the combined effects sliding velocity (SV) and martensite volume fraction (MVF) on tribological behavior dual-phase (DP) steel. Dry frictional tests were realized a ball-on-disk tribometer by unidirectional at 0.1 m/s, 0.6 1 m/s. Considering increase in SV, both friction coefficient (COF) wear rate decrease due to oxidative wear. At major mechanism is abrasive wear, ...

Abstract In this study, dual-phase (DP, ferrite + martensite) microstructures were obtained by performing intercritical heat treatments (IHT) at 750 and 800 °C followed quenching. Decreasing the IHT temperature from to leads to: (i) a decrease in volume fraction of austenite (martensite after quenching) 0.68 0.36; (ii) ~ 100 martensite start (Ms), mainly due higher carbon content its smaller gr...

The TA1 welded joints with different heat inputs were obtained by a fiber laser and their microstructure, mechanical properties corrosion resistance in simulated saliva solution studied. results show that the microstructure fusion zone (FZ) is needle-like ?? martensite lath-shape martensite, of heat-affected (HAZ) zigzag ? phase. With increase input, volume fraction decrease coarsened FZ, but t...

A finite element model coupled with a thermokinetic model is developed to predict the phase transformation of the laser deposition of AISI 4140 on a substrate with the same material. Four different deposition patterns, long-bead, short-bead, spiral-in, and spiral-out, are used to cover a similar area. Using a finite element model, the temperature history of the laser powder deposition (LPD) pro...