In the thermodynamic evaluation Y was selected as a typical heavy rare earth metal for reducing the detrmental effects of tramp elements in the petroleum pipe steel. The possibilities of reactions between Y and trampe...In the thermodynamic evaluation Y was selected as a typical heavy rare earth metal for reducing the detrmental effects of tramp elements in the petroleum pipe steel. The possibilities of reactions between Y and trampelements such as Sn, Sb, As, etc. after deoxidation and desulphurization were estimated by calculating the Gibbsfree energies of formation. The equilibrium content of Y for eliminating the detrimental effects of tramp elements inthe steel was recommended from the results of thermodynamic calculation.展开更多
The effect of the rare earth cerium （Ce） on the hypereutectic Al-Si alloy under different casting states have been studied by optical microscope and quantitative image analysis. It is found that the size and the qua...The effect of the rare earth cerium （Ce） on the hypereutectic Al-Si alloy under different casting states have been studied by optical microscope and quantitative image analysis. It is found that the size and the quantity of primary silicon in castings decrease with the increase of added Ce in the melt. Meanwhile primary silicon changes from branched shape to fine facetted shape. Although the modification on eutectic silicon in castings also improves with the increase of added Ce in the melt, the effect of modification on eutectic silicon away from primary silicon is more obvious than that on eutectic silicon close to primary silicon. The modification mechanism was analyzed in detail by means of scanning electron microscope equipped with energy dispersive analysis of X-ray and thermodynamics analysis, which included the analysis on the change in standard Gibbs energy of reaction and reaction equilibrium.展开更多
文摘In the thermodynamic evaluation Y was selected as a typical heavy rare earth metal for reducing the detrmental effects of tramp elements in the petroleum pipe steel. The possibilities of reactions between Y and trampelements such as Sn, Sb, As, etc. after deoxidation and desulphurization were estimated by calculating the Gibbsfree energies of formation. The equilibrium content of Y for eliminating the detrimental effects of tramp elements inthe steel was recommended from the results of thermodynamic calculation.
基金The work is financially supported by Shanghai Leading Academic Discipline Project (No. T0101)the Open Funds of Shanghai Key Laboratory of Metal Function Materials Research and Application.
文摘The effect of the rare earth cerium （Ce） on the hypereutectic Al-Si alloy under different casting states have been studied by optical microscope and quantitative image analysis. It is found that the size and the quantity of primary silicon in castings decrease with the increase of added Ce in the melt. Meanwhile primary silicon changes from branched shape to fine facetted shape. Although the modification on eutectic silicon in castings also improves with the increase of added Ce in the melt, the effect of modification on eutectic silicon away from primary silicon is more obvious than that on eutectic silicon close to primary silicon. The modification mechanism was analyzed in detail by means of scanning electron microscope equipped with energy dispersive analysis of X-ray and thermodynamics analysis, which included the analysis on the change in standard Gibbs energy of reaction and reaction equilibrium.
