US3916979A - Method for obtaining spheroidal graphite castings - Google Patents

Method for obtaining spheroidal graphite castings Download PDF

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Publication number
US3916979A
US3916979A US358229A US35822973A US3916979A US 3916979 A US3916979 A US 3916979A US 358229 A US358229 A US 358229A US 35822973 A US35822973 A US 35822973A US 3916979 A US3916979 A US 3916979A
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Prior art keywords
iron
pouring
agent
nodularizing
mould
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US358229A
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English (en)
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Michel Louis Degois
Daniel Christian Gouvenel
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Pont a Mousson SA
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Pont a Mousson SA
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/10—Making spheroidal graphite cast-iron

Definitions

  • a method for obtaining castings of spheroidal graphite iron, by treatment of the iron with a nodularizing agent comprising filling a pouring ladle with liquid iron pouring the iron from the ladle into a mould in the form of a stream of iron and incorporating the nodularizing agent into the stream of iron in a region between the pouringladle and the mould and as near as possible to the mould.
  • a device for carrying out said method comprises a pouring ladle and a mould, a pouring channel between the ladle and the mould and a device for supplying nodularizing agent combined with the pouring channel.
  • the present invention relates to the manufacture of spheroidal graphite castings by treating the iron with a nodularizing agent, such as pure magnesium or magnesium alloy, cerium etc.
  • the known technique of previously treating the iron before pouring it into the moulds has as drawback the fact that the liquid iron treated with a nodularizing agent is adversely affected by awaiting subsequent use and storage. It tends to lose its nodularizing agent so that the proportion of nodules of graphite upon solidification is lower. The graphite can even be completely lamellar.
  • An object of the invention is to overcome this drawback and to provide a method for obtaining spheroidal graphite castings, by treating the iron with a nodularizing agent, of the type comprising filling a pouring ladle with liquid iron and pouring said iron from said ladle into a mould in the form of a stream, wherein the nodularizing agent is incorporated in the liquid iron in said stream between the pouring ladle and the mould and as near as possible to the mould.
  • a whirling disturbance or turbulence is created in the flowing stream of liquid iron downstream of the region in which the nodularizing agent is introduced.
  • Another object of the invention is to provide a device for carrying out said method in the case of ⁇ a static pouring.
  • This device which is of the type comprising a pouring ladle and a fixed mould, has the feature that it comprises a pouring channel between the ladle and the mould and a device for feeding nodularizing agent combined with said channel.
  • FIG. 1 is a diagrammatic view of a device according to the invention for carrying out the method according to the invention in the case of pouring iron into a static mould;
  • FIGS. 2 and 3 represent micrographs showing the comparison of the structures of the spheroidal graphite castings obtained respectively in accordance with the known technique and in accordance with the method according to the invention in respect of a static mould;
  • FIG. 4 is a diagrammatic view of a device employed in the application of the method according to the invention to the casting of a pipe in a centrifugal casting mould, and
  • FIGS. 5 and 6 are comparative micrographs, similar to those of FIGS. 2 and 3, in respect of pipes cast by means of the method employing the device described with reference to FIG. 4.
  • the basic liquid iron untreated with magnesium contained in a tiltable pouring ladle 1 is poured into a chute 2 extended by a pouring channel 3 which is preferably short (for example 10-50 centimetres long).
  • This pouring channel 3 is inclined and its end is disposed above a pouring cup or funnel 4 of a static mould.
  • a hopper 6 Disposed above the upstream part of the channel 3 is a hopper 6 containing the required powdered nodularizing agent which is selected, for example, from magnesium and the alloys of the iron-silicon-magnesium, iron-silicon-magnesium-rare earths, nickel-magnesium or mischmetal type, the treating powder being very fine (OO.4 mm grain size).
  • This hopper 6 pours the nodularizing agent powder onto the iron by way of an adjustable orifice 7 so that it is possible to adjust the flow of the powder in accordance with the flow of the poured iron.
  • the percentage of nodularizing agent with respect to the weight of the iron is chosen, if this agent contains 5% magnesium, between 0.2 and 2% depending on the nature of the agent, the analysis of the basic iron and the thickness of the part being cast.
  • the pouring channel 3 is capped, downstream of the point at which the powder of nodularizing agent falls onto the iron, by a detachable hood 8 which is adapted to maintain a number of vertical or inclined bars of graphite 9 in the channel in such manner as to be partly immersed in the flowing stream of iron.
  • These bars 9 are aligned on a longitudinal axis of the channel or may be slightly laterally offset on each side of this axis so as to produce regions of whirling disturbances or turbulence in the stream of iron. Owing to these disturbances, the nodularizing agent powder floating on the surface of the iron is incorporated within the liquid metal immediately before its introduction into the mould 5.
  • FIGS. 2 and 3 illustrate, with a magnification of 100, the structures of the castings on one hand cast in moulds similar to the mould 5 shown in FIG. 1 with an iron previously treated in the pouring ladle according to the known technique (FIG. 2) and, on the other hand, cast by the aforementioned method and device according to the invention (FIG. 3).
  • FIGS. 2 and 3 illustrate, with a magnification of 100, the structures of the castings on one hand cast in moulds similar to the mould 5 shown in FIG. 1 with an iron previously treated in the pouring ladle according to the known technique (FIG. 2) and, on the other hand, cast by the aforementioned method and device according to the invention (FIG. 3).
  • FIGS. 2 and 3 illustrate, with a magnification of 100, the structures of the castings on one hand cast in moulds similar to the mould 5 shown in FIG. 1 with an iron previously treated in the pouring ladle according to the known technique (FIG. 2) and, on the other hand, cast by the a
  • Prior Art A basic iron having as mean analysis C 3.8%, Si 1.9%..S 0.007%, the remainder being iron, was treated ina ladle by the known method with 1.4%, with respect to the weight of the iron, of a nodularizing alloy Fe-Si-Mg containing 9% Mg. The yield of Mg was The iron thus treated gave, after inoculation with 0.3% by weight of a graphitizing alloy Fe-Si having 75% Si. a spheroidal graphite iron having 700 nodules/sq.mm and 60% pearlite (FIG. 2).
  • the method according to the invention is particularly advantageous when large pouring ladles are employed containing several tons of iron, for example 10 metric tons of iron, for filling a large number of moulds or for i casting large foundry parts, since there is no prior combustion and vaporization of the nodularizing agent (for example magnesium) in the large pouring ladle because the latter only contains ordinary as yet untreated iron in the method according to the invention.
  • the nodularizing agent for example magnesium
  • the invention is applied to the casting of a pipe by means of a device of the type described in French Pat. No. 1,456,844.
  • This device comprises a centrifugal casting mould 11 and a tiltable ladle 12 from which the iron is poured into a chute 13 extended by a pouring channel 14 which extends into the mould 11.
  • the channel and the mould undergo a relative movement of translation parallel to the channel and to the axis of the mould, the mould being itself rotated about its axis.
  • This pouring channel therefore differs from the pouring channel 3 of the preceding embodiment by its great length.
  • a hopper 15 containing the amount of nodularizing agent powder required for treating the iron.
  • This hopper pours the powder onto the iron by way of an adjustable orifice l6 which permits adjusting the flow of the powder in accordance with the flow of iron, for example by means of a needle valve member 17 actuated by a screw 18 having a control handle 19.
  • the channel 14 is covered downstream of the region in which the powder falls onto the iron by a detachable hood 20 which is adapted to maintain a number of bars 21 of graphite which extend inwardly of the channel to an extent which is sufficient to immerse the bars in the stream of molten iron.
  • FIGS. 5 and 6 permit a comparison of the results obtained by the prior art and those obtained by the method according to the invention. They represent structures of the iron halfway through the thickness of the wall of pipes having a nominal diameter of 800 mm and a wall thickness of 12 mm.
  • the following comparative examples show the surprising improvement in the results obtained by the method according to the invention in which the nodularizing agent is added to the stream of iron just before the introduction of the iron in the centrifugal casting mould, the agent being mixed with the iron by the creation of whirling disturbances or turbulence by the graphite bars 21.
  • the proportion of nodularizing agent employed depends, on one hand, on the rate of solidification of the casting, which is a function of the thickness of the casting (the thicker the casting the higher the content of Mg necessary to render the iron spheroidal graphite iron) and, on the other hand, on the content of sulphur and oligo elements in the basic iron.
  • a method for obtaining castings of spheroidal graphite iron, by treatment of the iron with a powdered nodularizing agent comprising filling a pouring ladle with liquid iron and pouring the iron from the ladle into an upstream end of a pouring trough which has a downstream end for pouring the liquid iron into a mould so that the iron flows in the trough in the form of a stream of iron, and incorporating the powdered nodularizing agent into the stream of iron in a region between the upstream end and downstream end of the trough and as near as possible to the downstream end of the trough, the flow of powdered nodularizing agent supplied to the liquid iron being adjusted in accordance with the flow of iron, and creating a turbulence in the stream of iron downstream of the region in which the nodularizing agent is incorporated.
  • a method as claimed in claim 1, comprising, in the case where the nodularizing agent is a Fe-Si-Mg alloy containing 12% magnesium, adding said agent to the iron in a proportion of about 1% by weight with respect to the iron poured.
  • a method as claimed in claim 1, comprising, in the case where the nodularizing agent is a Fe-Si-Mg-rare earths alloy containing 5% magnesium and 1% rare earths, adding said agent to the iron in a proportion of substantially 0.2-2% by weight with respect to the iron poured.
  • the nodularizing agent is a Fe-Si-Mg-rare earths alloy containing 5% magnesium and 1% rare earths

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
US358229A 1972-05-10 1973-05-08 Method for obtaining spheroidal graphite castings Expired - Lifetime US3916979A (en)

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FR7216809A FR2183577B1 (pt) 1972-05-10 1972-05-10

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US (1) US3916979A (pt)
BR (1) BR7303360D0 (pt)
CH (1) CH573474A5 (pt)
DE (1) DE2323419A1 (pt)
ES (1) ES414996A1 (pt)
FR (1) FR2183577B1 (pt)
IT (1) IT985849B (pt)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4036279A (en) * 1976-09-08 1977-07-19 Caterpillar Tractor Co. Method of treating molten metal in centrifugal castings
US4058153A (en) * 1974-07-18 1977-11-15 Pont-A-Mousson S.A. Process for centrifugally casting spheroidal graphite cast iron pipes
DE2653341B1 (de) * 1976-11-24 1978-02-16 Maschf Augsburg Nuernberg Ag Verfahren zum legieren und/oder impfen und/oder desoxidieren von im kupolofen erzeugten gusseisenschmelzen, sowie vorrichtung zur durchfuehrung des verfahrens
US4521455A (en) * 1982-02-23 1985-06-04 Csepel Muvek Femmuve Process and equipment for the production of alloyed copper wire rod by continuous casting
US5803153A (en) * 1994-05-19 1998-09-08 Rohatgi; Pradeep K. Nonferrous cast metal matrix composites

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2450400A1 (fr) * 1979-03-02 1980-09-26 Pont A Mousson Tuyau en fonte a graphite spheroidal
US4851095A (en) * 1988-02-08 1989-07-25 Optical Coating Laboratory, Inc. Magnetron sputtering apparatus and process

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2595292A (en) * 1949-10-05 1952-05-06 Herbert A Reece Method of adding alloys to metals
US3658115A (en) * 1970-11-30 1972-04-25 Gen Motors Corp Method of inoculating nodular cast iron
US3703922A (en) * 1968-07-17 1972-11-28 Materials & Methods Ltd Process for the manufacture of nodular cast iron
US3746078A (en) * 1971-02-04 1973-07-17 Meehanite Metal Corp Gating system for introducing additives to molten metal
US3819365A (en) * 1969-03-13 1974-06-25 Materials & Methods Ltd Process for the treatment of molten metals

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR975035A (fr) * 1948-09-21 1951-02-28 Procédé et appareil pour la désoxydation, l'affinage, l'inoculation et autres traitements analogues des métaux et alliages à l'état liquide
DE1248239B (de) * 1965-01-22 1967-08-24 Metallgesellschaft Ag Verfahren zum Impfen von Gusseisen
FR1456844A (fr) * 1965-09-14 1966-07-08 Ct De Rech S De Pont A Mousson Procédé et dispositif perfectionnés de coulée de la fonte par centrifugation

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2595292A (en) * 1949-10-05 1952-05-06 Herbert A Reece Method of adding alloys to metals
US3703922A (en) * 1968-07-17 1972-11-28 Materials & Methods Ltd Process for the manufacture of nodular cast iron
US3819365A (en) * 1969-03-13 1974-06-25 Materials & Methods Ltd Process for the treatment of molten metals
US3658115A (en) * 1970-11-30 1972-04-25 Gen Motors Corp Method of inoculating nodular cast iron
US3746078A (en) * 1971-02-04 1973-07-17 Meehanite Metal Corp Gating system for introducing additives to molten metal

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4058153A (en) * 1974-07-18 1977-11-15 Pont-A-Mousson S.A. Process for centrifugally casting spheroidal graphite cast iron pipes
US4036279A (en) * 1976-09-08 1977-07-19 Caterpillar Tractor Co. Method of treating molten metal in centrifugal castings
DE2653341B1 (de) * 1976-11-24 1978-02-16 Maschf Augsburg Nuernberg Ag Verfahren zum legieren und/oder impfen und/oder desoxidieren von im kupolofen erzeugten gusseisenschmelzen, sowie vorrichtung zur durchfuehrung des verfahrens
US4521455A (en) * 1982-02-23 1985-06-04 Csepel Muvek Femmuve Process and equipment for the production of alloyed copper wire rod by continuous casting
US5803153A (en) * 1994-05-19 1998-09-08 Rohatgi; Pradeep K. Nonferrous cast metal matrix composites

Also Published As

Publication number Publication date
BR7303360D0 (pt) 1974-06-27
CH573474A5 (pt) 1976-03-15
IT985849B (it) 1974-12-20
FR2183577A1 (pt) 1973-12-21
DE2323419A1 (de) 1973-11-29
FR2183577B1 (pt) 1974-09-27
ES414996A1 (es) 1976-05-16

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