摘要:
A sampling device for sampling a liquid or viscous comprises a receptacle, having a wall which is formed of a material having a higher melting point than that of the material, and a probe channel extending from outside the receptacle and to the receptacle's center of gravity. The receptacle is substantially spherical.
摘要:
A treatment ladle comprising a ladle shell containing a generally tubular refractory ladle liner, said ladle being pivotable between a horizontal position and a vertical position, said ladle liner having a first end and a second end with a continuous sidewall therebetween, an interior space being defined between said first and second ends and the continuous sidewall, said ladle liner additionally comprising a pocket for holding a treatment agent, said pocket being located adjacent the first end and in fluid communication with the interior space and located closer to the top than the bottom of the interior space when the ladle is in its horizontal position and closer to the bottom than the top of the interior space when the ladle is in its vertical position, and a spout for receiving and pouring molten metal located closer to the top than the bottom of the interior space when the ladle is in its horizontal and vertical positions, wherein in the horizontal position, a lower volume of the interior space defined below a plane midway between the top and bottom of the interior space and between the first end and a vertical plane intermediate the first and second ends is greater than an upper volume of the interior space defined above the midway plane and between the first end and said vertical plane. The treatment ladle is designed for the treatment of molten metal with vaporisable additives, in particular in the preparation of ductile iron. The invention also relates to a method of treating molten metal employing the ladle.
摘要:
A method of die casting spheroidal graphite cast iron able to prevent formation of chill crystals to allow the crystallization of fine spheroidal graphite and simultaneously prevent the formation of internal defects, including the steps of preparing a die formed with a heat insulation layer at inside walls of a cavity, filling molten metal having a composition of the spheroidal graphite cast iron through a runner into the cavity, closing the runner so as to seal the cavity right before the molten metal in the cavity starts to solidify, and allowing the molten metal to solidify by the action of the inside pressure caused by crystallization of the spheroidal graphite in the sealed cavity.
摘要:
It is possible to generate a desirable form (soft, pliable) of sulfide inclusions in magnesium-treated cast irons. Thermodynamically, MnS and MoS2 are not stable in the presence of magnesium. However, by adding magnesium to a cast iron melt containing manganese sulfide/molybdenium sulfide as late as possible, and preferably when the molten cast iron has been dispensed into the mould, such sulfide inclusions may be preserved in magnesium-treated cast irons. Alternatively, said cast iron can also be formed by adding said sulfides directly to the iron after the magnesium reaction has taken place and an in situ equilibrium has been established between magnesium, oxygen and sulfur. Another option is to begin with a sulfur content in excess of the stoichiometric amount required to combine with the added magnesium, thus ensureing an amount of left-over sulfur to promote the formation of the desired sulfide inclusions.
摘要:
The invention relates to a method of producing objects of cast iron containing compacted (vermicular) graphite crystals, by preparing a cast iron melt having substantially a carbon content at the desired final level and a silicon content below the desired final value, so that the equilibrium temperature (TE) for the reaction between carbon and SiO2 falls near 1400 °C, and adjusting the temperature of the melt (TM) to a value between the equilibrium temperature (TE) and the 'boiling temperature' (TB), to allow absorption of oxygen by the melt to a level exceeding the desired level at the time the melt is poured into a mould, adding the required amount of silicon, and thereafter reducing the oxygen content by addition of magnesium or a magnesium containing material, preferably a FeSiMg-alloy to an oxygen level of 10 to 20 ppm oxygen in liquid solution, and forming particles of magnesium silicates as well as cast objects obtained by the method.
摘要:
This invention covers the method and equipment for the continuous or discontinuous addition of reaction/inoculation materials necessary for desulphurization or the production of ductile iron obtainable during the passage of the base iron through a basin containing the chamber for melting, vaporizing and distributing the reaction-inoculation materials into the melt (e.g. magnesium vapour-Ferrum Silicon). The treatment can be conducted continuously for unlimited or freely definable quantities of iron.
摘要:
The invention relates to a method for manufacturing a single-piece cast product having an inhomogeneous distribution of the graphite crystals in vermicular and nodular form in different parts of the finished cast product. This is achieved by adjusting the composition and physical properties of the melt or the local nucleating potential, so that the melt, in dependence on solidification time and/or the local nucleating potential, will solidify with a larger proportion of vermicular graphite crystals in those parts of the casting in which a vermicular structure is desired. In those parts in which a higher proportion of nodular graphite crystals is desired at a correspondingly smaller proportion of vermicular graphite crystals in those parts where a nodular graphite structure is desired by adjusting the local nucleation potential, it is ensured that heat is transported more rapidly away from the casting during solidification, either by providing the casting with thin sections or by placing heat-absorbing elements in the mould. The method is particularly suited for the manufacture of engine parts and power transmission parts of automotive vehicles.
摘要:
A method relating to the production of cast iron castings with compacted graphite crystals. The method comprises controlling and correcting the composition of the cast iron melt and securing the necessary amount of structure modifying agent. A sample of the melt is taken with a sample vessel provided with two thermocouples, one positioned so as to be in the centre of the sample and the other positioned so as to be in the vicinity of the vessel wall. The vessel wall contains or is coated with a layer of a substance which will lower the concentration of dissolved elementary magnesium in the melt in the vicinity of the vessel wall by at least 0.003 %. The temperature/time values obtained through two temperature responsive means are recorded. The occurrence of a plateau temperature will provide information as to the precipitation of flaky graphite in the vicinity of the vessel wall, therewith enabling corrections to be made to the concentration of the modifying agent and to ensure the formation of compacted graphite crystals during the whole of the pouring time required in the foundry processconcerned.