The effect of water ratio in secondary cooling zone on billet cooling speed, solidification structure and center carbon segregation index of 0.64% - 0.82%C steel 150 mm×150 mm billet casting with 250A/5Hz electromagnetic stirring has been tested.
The data obtained by a test are as follows: Under the conditions that the reeling temperature and cooling velocity were 600℃, 9℃/s or 630℃, 19℃/s respectively, the steel exhibited a good mechanical performance, that is ab = 60kg/mm2, τs =50kg/mm2, aK-40=7.5kg. m/cm2, and completely reached the level of class X70.
It is found that increase of shear stress and cooling velocity may benefit the enhancement of mechanical properties . The notched impact strength,tensile strength and elongation at break of PP/UHMWPE composites with composition ration of 90/10,can be 88.6kJ/m 2,45 1kpa,and 570%,respectively and correspondingly being 3.5,1.5 and 2.5 time of the value for PP 1330 However.
For the Co-free MlNi4.0Al0.3Si0.1Fe0.6 alloys, prepared by conventional casting (as-cast) and melt-spinning with different cooling rates(5,10,15,20m/s), the phase structure and electrochemical properties of these alloys were comparatively studied.
The differential scanning calorimeter (DSC ) analysis indicats that the melting point temperature and separating out temperature of eutectic are 345 ℃ and 328.7 ℃ respectively at heating and cooling rates of 15 K/min and 10 K/min.
Comparing with eutectoid steel,the microstructure of F+P+B was observed when the cooling rates down to 2.5 ℃/s,while the microstructure of F+B was obtained when the cooling rates ranging from 2.5 ℃/s to 25 ℃/s.
The increase in the cooling rate can restrain the precipitation of the Ga-rich phase in the ribbon.
With a given law p=f(T), such parameters are the temperature Ts at the dew point and the mean cooling rate
The convective heat flux is mainly determined by the Rayleigh number and depends only slightly on the layer heating (cooling) rate.
Dependence of the Fluctuation Free Volume of Amorphous Substances on the Cooling Rate
The dependence of the fraction fg of fluctuation free volume (frozen at the glass transition temperature) on the cooling rate is determined using the Bartenev equation for the dependence of the glass transition temperature on the cooling rate.