Research Of The Impact About Chemical Composition And Melting Process On Structure And Properties Of Short Process Gray Cast Iron

This topic by using ferrosilicon, silicon barium silicon calcium and rare earth breeding method to change the chemical composition of short process began to study the influence of mechanical properties of the gray cast iron, as well as the change of cooling rate on the short process of grey cast iron metallographic organization, by the comparison of multiple sets of experimental data, it is concluded that the optimal addition amount of inoculant and best cooling speed.Mechanics performance, ferrosilicon inoculant addition amount at 0.25%, the overall mechanical performance is best. After inoculation doses of more than 0.25%, the blast furnace hot metal hereditary and began to emerge.Silicon barium inoculant addition amount in 0.5%, the highest tensile strength and the coefficient of the highest quality, the best overall mechanical properties.Silicon calcium inoculant addition amount at 0.5% when it reached the highest tensile strength, the same tensile strength, to join the calcium silicon inoculant, a join other inoculant low 20-30 hardness.Rare earth inoculant addition amount in 0.13%, the tensile strength has reached more than 200 mpa, inoculant addition amount at 0.48%, as a gray cast iron, the overall mechanical performance is the best.Metallographic and matrix organization, along with the increase in inoculation dose, type A graphite, graphite length shortening, distribution more uniform.All of pearlite and ferrite matrix, and the nucleating agent can promote graphitization, reduce chilling tendency and lower iron liquid supercooling tendency, improve the graphite morphology and distribution, increase the number of heterogeneous nucleation, improve the uniformity of the microstructure and mechanical properties, refining matrix organization.But after more than a certain amount, bulky graphite began to appear, may be associated with high carbon equivalent blast furnace hot metal itself.White experiments, triangle block less thin-walled graphite, cementite is more, hardness higher;With the increase of wall thickness, graphite increased, cementite decreases, hardness is reduced, and graphite is more and more evenly.In addition, the addition of nucleating agent can make the triangle block fracture surface obviously refined grains.Comprehensive experiment ferrosilicon inoculant addition amount of 0.25%, silicon barium inoculant addition amount of 0.5%, silicon calcium inoculant addition amount of 0.5%, rare earth inoculant addition amount of 0.48%, for the wall thickness is more than 10 mm grey cast iron inoculation effect is best.