30results about How to "Good shape of graphite" patented technology

A method for casting a box-type complex water-cooling exhaust pipe by using an iron mold coated sand is disclosed. By using the water-free coated sand mold, the method helps to realize rapid cooling and mold filling, eliminate the defects of nail-passing-hole structure loosening and casting deformation often happening in the water-cooling exhaust pipe; and the prepared water-cooling exhaust pipe has higher tensile strength, higher hardness, better graphite morphology and better graphite grade, and the amount of stable pearlites is 98% or more. The yield of castings is improved from 54% to 96% or more. The finished product is good in texture compactness, good in texture refining capability, good in surface quality, and stable and reliable in quality. Also, during the production, the method has the advantages of being small in use level of the sand and paints, small in equipment investment, small in equipment occupied area, high in production efficiency, low in manufacture cost, good in environmental protection property, wide in prospect, and applicable to production of various engine exhaust pipes with high quality demands and complex thin-wall double-layer walls.

The invention discloses a method for improving the structure and performance of ductile cast iron; it relates to the technical field of cast iron, and introduces graphene composite particles into ductile cast iron to obtain finished ductile iron castings; the introduction is added to molten ductile cast iron after ball milling treatment Graphene composite particles; the ball milling process is mixed ball milling of iron powder and graphene composite particles; the added amount of graphene composite particles in the finished ductile iron casting is 0.25-0.33wt.%; the graphite prepared by the inventive method Graphene composite particles can significantly improve the spheroidization rate of nodular cast iron. By improving the spheroidization rate, the graphite spheres are more rounded. During the solidification process, graphite distortion mainly occurs during the growth of spheroidal graphite in molten iron. Among them, the reduction of growth rate can reduce the probability of distortion. Therefore, by introducing the graphene composite particles prepared by the present invention, the nodularization rate of ductile iron can be greatly increased, and its mechanical properties can be further improved.

The invention discloses a reinforced chilled roll. The reinforced chilled roll comprises an outer alloy layer and a core portion, and a medium layer is arranged between the outer alloy layer and the core portion. By the aid of the medium layer arranged between the outer alloy layer and the core portion, combination instability of an original outer alloy layer and the core portion is improved. In addition, graphite form and number of the alloy outer layer can be obtained and improved in the ideal form by means of adding a preliminary inoculation processing procedure and a microalloying processing procedure to a casting process and controlling nodulizer explosion time. Besides, the performance of the reinforced chilled roll is improved by means of refined crystalline strengthening and strain strengthening of microalloy beneficial elements, quality problems of slag dropping and small spalling are avoided, and steel passing quantity is increased obviously.

The invention provides a melting ingredient for a piston, and the melting ingredient is mainly used for solving the problems that the pistons cast and formed from the existing melting ingredient are easy to deform and wear and have lower hardness and larger brittleness. The melting ingredient for the piston comprises the following components in percentage by weight: 2.3-3.5 of carbon, 1.7-2.2 of silicon, 0.6-0.9 of manganese, 0-0.12 of sulfur, 0-0.1 of phosphorus, 0-0.06 of chrome, 0.01-0.02 of antimony, 0.2-0.5 of copper and the balance of iron. The melting ingredient for the piston is molten, casted and formed to obtain a piston finished product; and the obtained piston finished product is not easy to deform and wear and has the advantages of high tensile strength, less brittleness, good graphite morphology and lower cost.

The invention relates to a high-strength and high-wear-resistance vanadium-titanium cast iron brake drum manufacturing technology for automobiles, specifically a method for preparing a vanadium-titanium gray cast iron brake drum. The preparation method includes the following steps: melting the original molten iron: Vanadium-titanium pig iron, scrap steel, furnace charge, recarburizer, ferrosilicon, ferromanganese, and ferrochrome are used as the charge, and the recarburizer is added to the bottom of the furnace, and the charge is smelted in an intermediate frequency induction furnace to obtain the original molten iron. After the molten iron is melted Raise the temperature and overheat to purify the molten iron, then keep it warm at 1520-1530°C; then carry out slag removal, add a slag accumulator on the surface to keep it warm, and then add a small amount of recycled material to adjust the composition of the molten iron. The invention adopts the process of adding a small amount of returned material to increase the heterogeneous core in the later stage of smelting to reduce the tendency of molten iron to be white, improve the graphitization ability of molten iron, and improve the inoculation effect; adopt the secondary inoculation treatment process of the tapping trough and the sprue cup to improve the inoculation effect , Improve graphite morphology, eliminate carbide and ferrite, increase pearlite content.

The invention relates to a point inoculation device and a point inoculation method. The point inoculation device is characterized by comprising a package, and inoculation materials consisting of inoculators and nodulizers are filled in the package. The point inoculation method includes proportionally mixing the inoculators with the nodulizers to form the inoculation materials; filling the inoculation materials in an inner cavity of the package; fixing the package filled with the inoculation materials to a specific position of a casting required to be subjected to inoculation before the casting is subjected to pouring; and pouring molten metal into a sand mold and enabling the inoculation materials to perform point inoculation for the specific position of the casting. According to the technical scheme, the point inoculation device and the point inoculation method have the advantages that the package is melted after pouring is completed, and the inoculators and the nodulizers are exposed in the molten metal and are reacted with the molten metal, so that inoculation can be implemented for the specific position of the casting, the specific position of the casting is high in nodularity, the metallographic structure and the graphite morphology of the specific position of the casting are improved, and the machining performance of the specific position of the casting is enhanced.

The invention discloses a manufacturing technology and device for an improved forged steel roller neck high nickel chrome molybdenum alloy cast composite roller. The roller comprises, by mass percent, 3.0%-3.6% of C, 0.60%-1.20% of Si, 0.30%-1.20% of Mn, 3.0%-5.0% of Ni, 1.0%-2.0% of Cr, 0.40%-1.2% of Mo, 0.1%-2% of W, 0.5%-1.0% of Cu, not larger than 0.05% of P, not larger than 0.03% of S, 0.04%-0.06% of Mg, 0.1%-0.3% of Nb, 0.1%-0.30% of Ti, 0.2%-0.6% of V, 0.05%-0.2% of B, 1.5%-2.5% of Ba, 1%-2% of Ca, 1%-3% of Sb, 0.02%-0.18% of N, 1.0%-2.0% of Y / RE and the balance Fe and inevitable micro elements. Yttrium base rare-earth nodulizing and Ba, Ca, and silicon iron composite inoculation are adopted, Nb, Ti, V, B and Sb are added for modification, and the mechanical performance of the roller is improved; by the adoption of the forged steel roller neck, the strength of the roller is improved, an induction heater is adopted to carry out in-mold whole heating casting on a core stick, a water cooled crystallizer is molded, a composite layer interface can be dynamically controlled, the technology is simple, the efficiency is high, power consumption is small, the cost is low, no composition segregation exists, and the service life of the roller is long.

The invention discloses gray cast iron and a preparation method thereof, and belongs to the field of metal casting. The gray cast iron and the preparation method solve the technical problems that existing gray cast iron is high in production cost and insufficient in performance. According to the gray cast iron and the preparation method, precious metal such as copper, molybdenum, nickel and vanadium is not added, strength and hardness of castings are improved through chromium and antimony, the manufacturing cost is reduced, and performance of the gray cast iron can be improved by conducting microalloying on antimony and chromium together.