WO2006068487A1 - Agents modificateurs pour fonte - Google Patents

Agents modificateurs pour fonte Download PDF

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Publication number
WO2006068487A1
WO2006068487A1 PCT/NO2005/000022 NO2005000022W WO2006068487A1 WO 2006068487 A1 WO2006068487 A1 WO 2006068487A1 NO 2005000022 W NO2005000022 W NO 2005000022W WO 2006068487 A1 WO2006068487 A1 WO 2006068487A1
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inoculant
iron
melt
pearlite
modifying
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PCT/NO2005/000022
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English (en)
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Torbjørn SKALAND
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Elkem Asa
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Publication of WO2006068487A1 publication Critical patent/WO2006068487A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C37/00—Cast-iron alloys
    • C22C37/10—Cast-iron alloys containing aluminium or silicon
    • 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
    • C21C1/105—Nodularising additive agents
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C37/00—Cast-iron alloys
    • C22C37/06—Cast-iron alloys containing chromium

Definitions

  • This invention relates to modifying agents for cast iron (grey, ductile and compacted) and more particularly inoculants that make it possible to control not only the graphite structure in cast iron, but also the matrix microstructure of the cast iron.
  • Inoculants are traditionally designed to manipulate graphite nucleation in cast iron, and promote desirable structures such as type A graphite in grey irons and high nodule counts in ductile irons.
  • a wide range of inoculant alloys is known that cover different needs for graphite structure control.
  • graphite typically accounts for only about 10% of the cast iron microstructure, and the remaining 90% being constituents such as ferrite, pearlite or carbides.
  • Some inoculants are however recognised as being useful in directing microstructures towards ferritic or pearlitic grades, but no special attempt has been made in order to enhance this situation deliberately.
  • Elements that are recognised as ferrite promoters in cast iron are Si, Ni and Al, but generally concentrations need to be high in order to ensure fully ferritic conditions and there are other downsides to this as well.
  • the most practical way to produce as- cast ferritic microstructures in ductile iron today is simply to ensure that the concentration of pearlite promoters is kept low, and this often implies the use of high pig iron contents in the charge. Therefore it would be useful to introduce an inoculant that could promote ferritic microstructures out of a more common ferritic/pearlite base iron, without having to restrict the content of pearlite promoters in the iron.
  • Some pearlite promoters that are used today in making high strength pearlitic grades include Mn, Cu, Sn, Sb and Cr. However, the introduction of such elements into the charge for producing cast iron would restrict the usefulness of the charge for other grades of iron than pearlitic grades.
  • a method of controlling the microstructure of a cast iron which comprises: forming an iron melt; removing a portion of the melt; adding a modifying agent to the removed portion; and then casting the removed portion; the modifying agent comprising a graphite phase modifying compound and a matrix structure modifying component.
  • the cast iron melt may be formed from one or more of scrap iron, steel scrap, cast iron returns and pig iron, optionally together with one or more of ferrosilicon, ferromanganese, manganese and carbon to adjust the final cast iron composition.
  • the said portion is removed to a mould and the inoculant is added to the removed portion in the mould or as it enters the mould.
  • the amount of inoculant added represents from 0.1 to 1.5 wt % of the removed portion.
  • the matrix structure modifying component in the additive may be a pearlite promoter, such as tin (Sn) or antimony (Sb) or arsenic (As), or a ferrite promoter, such as boron (B).
  • a pearlite promoter such as tin (Sn) or antimony (Sb) or arsenic (As)
  • a ferrite promoter such as boron (B).
  • the inoculant may include 5 to 40 wt % Sn and/or 3 to 15 wt % Sb 3 and/or 0.3 to 7 wt % As, or 0.3 to 6 wt % B, based on total weight of the inoculant.
  • the content would be 6 to 15 wt % Sn and/or 3.3 to 10 wt % Sb, and/or 0.5 to 5 wt % As 3 or 0.3 to 6 wt % B. Combinations of these are also contemplated.
  • the inoculant is ferrosilicon-based and the graphite phase modifying component comprises from 40 to 80 wt % Si and from 0.5 to 10 wt % Ca and/or Sr and/or Ba, the balance being predominantly Fe.
  • the graphite phase modifying component may also include up to 10 wt % Ce and/or La, up to 5 wt % Mg, up to 5 wt % Al, up to 10 wt % Mn and/or Ti and/or Zr (preferably 0.5 to 5 wt %), and may also include from 0.5 to 10 wt % oxygen in the form of one or more metal oxides and from 0.1 to 10 wt % sulphur in the fonn of one or more metal sulphides.
  • the inoculant may be in the form of a solid mixture of a ferrosilicon based alloy, the metal oxide and the metal sulphide.
  • the metal oxide is selected from the group consisting of FeO, Fe 2 O 3 , Fe 3 O 4 , SiO 2 , MnO, MgO, CaO, Al 2 O 3 , TiO 2 and CaSiO 3 , CeO 2 , ZrO 2 and the metal sulphide is selected from the group consisting of FeS, FeS 2 , MnS, MgS, CaS and CuS.
  • the oxygen content is between 1 and 6% by weight and the sulphur content is between 0.1 and 3% by weight.
  • the inoculant is added in an amount in the range 0.2 to 1.5 wt % based on the total weight of the melt to which it is added.
  • a portion of the melt is removed and transferred to a treatment ladle, a nodulariser is added to the removed portion of the melt in the ladle, and the inoculant is then added to at least a part of the removed portion.
  • the nodulariser can be placed in the treatment ladle before the melt is poured in or can be added to the melt in the treatment ladle.
  • the nodularised melt may then be poured into a pouring ladle to be poured into one or a plurality of moulds.
  • the inoculant can then be added to the stream during transfer to the pouring ladle or added to the stream as the melt enters each mould.
  • Suitable nodularisers include a ferrosilicon- based nodulariser comprising: 40 to 60 wt % Si; 3 to 20 wt% Mg; and optionally up to 5 wt % Ca; up to 10 wt % rare earth metals, Ce and/or La; and up to 5 wt % Al; based on the total weight of the nodulariser; the balance being Fe.
  • the nodulariser may contain tin and/or antimony and/or arsenic or boron as matrix structure modifying components.
  • the contents, based on the total weight of the nodulariser, are preferably 1 to 15 wt % Sn, and/or 0.4 to 10 wt % Sb and/or 0.1 to 5 wt % As or 0.2 to 3 wt % B, more preferably 2.5 to 10 wt % Sn, and/or 0.5 to 5 wt % Sb and/or 0.2-3% As or 0.25 to 2.5 wt % B.
  • the invention extends to a cast iron modifying agent, such as an inoculant or a nodulariser, comprising a graphite phase modifying component and a matrix structure modifying component, the matrix structure modifying component comprising Sn and/or Sb, and/or As or B.
  • a cast iron modifying agent such as an inoculant or a nodulariser
  • the graphite phase modifying component comprises: Si, Ca and/or Sr and/or Ba, and Al, and may comprise rare earth metals, Ti, Zr and Mn.
  • the matrix structure modifying component may be a pearlite promoter comprising 5 to 40 wt % Sn and/or 3 to 15 wt % Sb and/or 0.3 to 7 wt % As, based on the total weight of the modifying agent, preferably 6 to 15 wt % Sn and/or 3.3 to 10 % Sb and/or 0.5 to 5 wt % As.
  • the matrix structure modifying component is a ferrite promoter comprising 0.3 to 6 wt % B, based on the total weight of the modifying agent, preferably 0.5 to 3.5 wt % B.
  • the graphite phase modifying component is as described above in relation to the method of the invention.
  • the modifying agent is an inoculant, it may also include the various other components and have the various properties mentioned above in relation to the inoculant.
  • it is a nodulariser, it may include the various components and have the properties mentioned above in relation to the nodulariser.
  • the invention also extends to a method of treating molten cast iron with a modifying agent as described above. More specifically, the invention extends to forming an iron melt, removing a portion of the melt, treating the removed portion with the inoculant and casting the treated portion.
  • the portion is removed to a mould and the inoculant is added to the removed portion in the mould or as it enters the mould.
  • the amount of inoculant added represents from 0.2 to 1.5 wt % of the removed portion.
  • the melt Prior to inoculation, the melt may be treated with a nodulariser, preferably as described above.
  • the invention provides a method of producing cast irons with differing microstructures from the same melt, which comprises: forming an iron melt; removing a first portion of the melt; adding a first inoculant including a first matrix structure modifying component to the first portion; removing a second portion of the melt; adding a second inoculant including a second matrix structure modifying component to the second portion; and casting the two portions; the two matrix structure modifying components being a pearlite promoter and a ferrite promoter.
  • the two will be a pearlite promoter and the other a ferrite promoter.
  • the pearlite promoter is preferably Sn and/or Sb and/or As
  • the ferrite promoter is preferably B.
  • Both inoculants are preferably ferrosilicon-based, and both preferably include a graphite phase modifying component, as set out above.
  • each inoculant is added to its respective melt portion in an amount in the range 0.2 to 1.5 wt % based on the total weight of the melt.
  • a nodulariser Prior to inoculation, optionally one or both portions of the melt may be treated with a nodulariser.
  • the nodulariser is preferably added as set out above, and is preferably similar to the nodulariser described above in its composition.
  • FIGS. Ia and 2b are sequential, schematic representations of a process possibility in according with the invention.
  • FIGS. 2a to 2c are sequential representations of another process possibility in accordance with the invention.
  • FIGS 3, 4, 5, 6 and 7 are photomicrographs showing the structure of various test alloys
  • Figures Ia and Ib show a melting furnace 11 (though this could equally well be a holding furnace), a pouring ladle 12 and a series of two-part moulds, two of which 13,14 are shown.
  • the furnace 11 contains an iron melt 15 which has not been treated with any inoculant.
  • a portion 16 of the melt 15 is poured into the pouring ladle 12 from the furnace 11 as shown in Figure Ia.
  • the portion of melt 16 in the pouring ladle 12 is then poured sequentially into the two-part moulds 13,14 as shown in Figure Ib. Any slag on the surface of the melt 16 is held back by a weir 17 in the pouring ladle 12.
  • an inoculant 18 is added to the stream 19 of molten iron as enters the mould 13,14.
  • the iron is then allowed to cool and solidify in the moulds.
  • the inoculant 18 includes not only a graphite phase modifying component, as is conventional, but also a matrix structure modifying component which determines the nature of the matrix.
  • an inoculant 18 which has tin (Sn) and/or antimony (Sb) and/or as arsen (As) the matrix structure modifying component.
  • an inoculant 18 which has boron (B) as the matrix structure modifying component.
  • FIG. 2a to 2c The process shown in Figure 2a to 2c is similar to that in Figures Ia and Ib and includes a furnace 21 holding an iron melt 22. However, in this case, as shown in Figure 2a, a portion 24 of the melt 22 is transferred to a treatment ladle 23.
  • the treatment ladle 23 includes a nodulariser 25 which dissolves in the melt portion 24 in the treatment ladle 23.
  • the nodulariser-treated molten iron is then poured from the treatment ladle 23 into a pouring ladle 26, as shown in Figure 2b. Again, a weir 27 in the treatment ladle 23 prevents slag entering the pouring ladle 26.
  • the nodularised iron melt 28 in the pouring ladle 26 is poured sequentially into two part moulds 31, 32 as shown in Figure 2c. Any slag on the surface of the melt 28 is held back by a weir 29 in the pouring ladle 26. As the melt 28 is poured, an inoculant 33 is added to the stream 34 of molten iron as it enters the mould 13,14.
  • the iron is then allowed to cool and solidify in the moulds.
  • the inoculant 33 and its use are similar to the inoculant 18 and its use in the embodiment of Figures Ia and Ib.
  • the inoculant comprises a graphite phase modifying component and a matrix structure modifying component.
  • the matrix structure modifying component can be a pearlite promoter such as Sn, Sb or As, or a ferrite promoter such as B.
  • compositions of ferrosilicon based inoculants are given in Table 1, while Table 2 shows the resulting nodule count and pearlite content in 5, 20 and 40 mm section size sand moulded ductile iron plates.
  • Table 2 Nodule count and pearlite content in experimental ductile iron castings.
  • Inoculants A and C are conventional reference materials to the experimental inoculant B containing 3.7% Sb in addition to Ca, Al and Ce.
  • the objective with inoculant B was to promote a predominantly pearlitic microstructure in all section sizes of the experimental ductile iron castings.
  • Table 2 shows that the reference inoculants A and C gave pearlite contents ranging from about 60% in the 5 mm section to about 8% in the 40 mm section plates.
  • the experimental antimony bearing inoculant B gave pearlite contents around 80% for all casting plate thicknesses. This means that inoculant B is useful in achieving higher and more uniform pearlite contents in complex castings of different section thicknesses.
  • the antimony bearing inoculant B is found to be useful in promoting significantly more pearlite in the microstructure.
  • Such inoculants may therefore be used as means to make higher strength pearlitic microstructures in ductile iron of a relatively low alloying content that would otherwise solidify as predominantly ferritic microstructures.
  • Heats of liquid iron were made up from steel scrap, pig iron, ferrosilicon, ferramanganese, copper, and graphite, and melted in an induction furnace. Nodularising treatment was conducted in a conventional tundish ladle process by adding 1.6 wt% of a 6%Mg-bearing ferrosilicon alloy followed by addition of 0.3 wt% inoculant at transfer to the pouring ladle. Final iron composition was 3.7%C, 2.6%Si, 0.6%Mn, 0.62%Cu, 0.03%Mg, and 0.01%S.
  • compositions of experimental ferrosilicon-based inoculants are given in Table 3, while Table 4 shows the resulting nodule count and pearlite content in 20 mm section size sand moulded ductile iron plates.
  • Table 3 Composition of experimental ferrosilicon-based inoculants.
  • Table 2 Nodule count and pearlite content in 20 mm ductile iron plates.
  • Inoculants A and B are conventional reference materials to the experimental inoculants C and D containing 1.1% B in addition to Ca, Al, Ce, S, and O.
  • the objective with inoculants C and D was to promote more ferrite in the microstructure of the experimental ductile iron castings.
  • Table 4 shows that the reference inoculants A and B gave pearlite contents of about 70% in the 20 mm section plates, while the experimental boron bearing inoculants C and D gave pearlite contents of only around 20 to 30% for the same conditions. This means that inoculants C and D are useful in achieving higher ferrite contents in castings where the base alloying conditions (Mn and Cu) are promoting mostly pearlitic microstructures.
  • the boron pick-up to the final iron was found to be about 10 to 15 ppm for the experimental irons No. 3 and 4.
  • Reference irons No. 1 and 2 have no detectable boron content in the final treated metals.
  • Boron bearing inoculants are found to be useful in promoting significantly more ferrite and less pearlite in the microstructure of 0.6% Mn and 0.6%Cu alloyed ductile iron. Such inoculants may therefore be used as means to make higher ductility grades of ductile iron out of pearlitic base iron conditions that would otherwise solidify having predominantly pearlitic microstructures.
  • Heats of liquid grey iron were made up from steel scrap, pig iron, ferrosilicon, ferromanganese, sulphur, and graphite, and melted in an induction furnace. Inoculation was conducted by the addition of 0.25 wt% inoculant at transfer to the pouring ladle. Final iron composition was 3.3%C, 2.0%Si, 0.45%Mn, 0.23%Cr, and 0.06%S.
  • compositions of experimental ferrosilicon-based inoculants are given in Table 5, while Table 6 shows the resulting chill wedge level, graphite structure (type A graphite), and pearlite content in 20 mm section size sand moulded grey iron plates. 1
  • Table 5 Composition of experimental ferrosilicon-based inoculants.
  • Inoculant A is a conventional Sr-bearing reference material for the experimental inoculants B and C containing 3.9% Sb and 10% Sn, respectively in addition to Sr.
  • Inoculant D is another experimental material containing 3.7% Sb in addition to Ca, Al, and Ce.
  • the objective with the experimental inoculants B, C and D was to promote more pearlite in the microstructure of grey iron castings.
  • Table 6 shows that the reference inoculant A gave pearlite contents of about 88% in the 20 mm section plates, while the experimental Sb and Sn bearing inoculants B, C and D gave pearlite contents of 97 to 100% for the same conditions.
  • inoculants B, C and D were useful in achieving fully pearlitic conditions in castings that would otherwise solidify with a certain ferrite content.
  • Table 6 shows that the experimental inoculants gave a moderately increased chilling tendency in standard cast chill wedges from 7 mm chill for the reference inoculant to about 10 mm chill for the experimental inoculants. This is expected since Sb and Sn alloying tend to give pearlite and chill promotion effects simultaneously. Chill wedge levels were however fully acceptable, and could be largely offset by slightly increasing the inoculant alloy addition rate.
  • antimony and tin bearing inoculants are found to be useful in ensuring fully pearlitic microstructures in somewhat undercooled and low alloyed grey iron conditions.
  • Such inoculants may be used as means to promote higher strength pearlitic grades of grey iron of a relatively low alloying content that would otherwise risk to contain undercooled type D graphite and associated ferrite formation with the accompanied risk of inferior tensile strength properties.
  • Heats of liquid iron were made up from steel scrap, pig iron, ferrosilicon, ferromanganese, and graphite, and melted in an induction furnace. Nodularising treatment was conducted in a conventional tundish ladle process by adding 1.6 wt% of a 6%Mg-bearing ferrosilicon alloy followed by the addition of 0.4 wt% inoculant at transfer to the pouring ladle. Final iron composition was 3.7%C, 2.6%Si, 0.50%Mn, 0.033%Mg, and 0.006%S.
  • Table 7 Composition of experimental ferrosilicon-based inoculants.
  • Inoculant A is a conventional reference material to the experimental inoculants B through E containing from 2 to 8 % Sb in addition to Ca, Al, Zr, Mn and Ba.
  • the objective with inoculants B through E was to investigate the pearlite promoting effect as a function of increasing Sb-content in the inoculant.
  • Table 8 shows that the reference inoculant A gave a pearlite content of 37% in the present iron for the 20 mm section plate.
  • the experimental antimony bearing inoculants B through E gave pearlite contents ranging from 62% for the 2% Sb-containing inoculant B to 99% for the 8% Sb-containing inoculant E. This means that increasing Sb-contents in conventional ferrosilicon based inoculants is useful to increase the pearlite content from initially less than 50% and towards 100% pearlite.
  • Figures 3a, 3b and 3c show the microstructure in experimental 20 mm plate castings No. 1, 3, and 5 respectively in Table 8.
  • the residual Sb-content in these castings is increasing from ⁇ 0.003% in the reference iron to 0.03% Sb in iron No. 5 treated with the 8%Sb-containing inoculant E.
  • Sb-containing ferrosilicon inoculants may therefore be useful as a means to make higher strength pearlitic grades of ductile iron having a relatively low initial alloying content that would otherwise solidify with predominantly ferritic microstructures.
  • the content of Sb in the inoculant may be adjusted between say 3 and 15% in order to achieve the required level of pearlite and consequently the required strength level of the ductile iron casting.
  • Heats of liquid iron were made up from steel scrap, pig iron, ferrosilicon, ferromanganese, graphite, and copper, and melted in an induction furnace. Nodularising treatment was conducted in a conventional tundish ladle process by adding 1.6 wt% of a 6%Mg-bearmg ferrosilicon alloy followed by addition of 0.4 wt% inoculant at transfer to the pouring ladle. Final iron composition was 3.75%C, 2.60%Si, 0.73%Mn, 0.040%Mg, 0.006%S, and 0.72%Cu.
  • compositions of experimental ferrosilicon-based inoculants are given in Table 9, while Table 10 shows the resulting nodule count, nodularity, pearlite content and boron content in 20 mm section size sand moulded ductile iron plates.
  • Table 9 Composition of experimental ferrosilicon-based inoculants.
  • Table 10 Nodule count, nodularity, pearlite and boron-contents in ductile irons.
  • Inoculant A is a conventional reference material to the experimental inoculants B through E containing from 0.7 to 2.8 % B in addition to Ca and Al.
  • the objective with inoculants B through E was to investigate the ferrite promoting effect as a function of increasing B-content in the inoculant.
  • Table 10 shows that the reference inoculant A resulted in a pearlite content of 96% in the present 0.7%Mn and 0.7%Cu containing iron for the 20 mm section plate.
  • the experimental boron bearing inoculants B through E gave pearlite contents ranging from 70% for the 0.7% B-containing inoculant B to 51% for the 2.8% B-containing inoculant E.
  • FIGS. 4a, 4b and 4c show examples of the microstructure in experimental 20 mm castings No. 1, 3, and 5 respectively from Table 9. The residual B-content in these castings is increasing from ⁇ 5 ppm in the reference iron to 70 ppm B in iron No. 5 treated with the 2.8% B-containing inoculant E.
  • B-containing ferrosilicon inoculants may therefore be useful as a means to soften higher strength pearlitic grades of ductile iron that would otherwise solidify with predominantly pearlitic microstructures.
  • the content of B in the inoculant may be adjusted between say 0.3 and 6% in order to achieve the required level of ferrite and pearlite and consequently the required strength and ductility level of the ductile iron casting.
  • Heats of liquid iron were made up from steel scrap, pig iron, ferrosilicon, ferromanganese, graphite, and copper, and melted in an induction furnace.
  • Nodularising treatment was conducted in a conventional tundish ladle process by adding 1.6 wt% of experimental 6%Mg-bearing ferrosilicon alloys followed by addition of 0.4 wt% inoculant at transfer to the pouring ladle.
  • Final iron composition was 3.6%C, 2.9%Si, 0.18%Mn, 0.038%Mg, and 0.01%S for tests 1 through 5 and. 3.75%C, 2.55%Si, 0.6%Mn, 0.035%Mg, 0.006%S, and 0.23%Cu for tests 6 through
  • compositions of experimental ferrosilicon-based nodularisers and inoculants are given in Tables 11 and 12, while Table 13 shows the resulting nodule count, nodularity, pearlite content and antimony content in 20 mm section size sand moulded ductile iron plates.
  • Table 11 Composition of experimental ferrosilicon-based nodularisers.
  • J ⁇ fe i3 Nodule count, nodularity, pearlite and antimony-contents in ductile irons.
  • MgFeSi nodulariser A is a conventional reference material containing about 6%Mg and l%Ca and RE, while the experimental nodulariser B also contains 0.8% Sb.
  • Inoculants A, B, and D are conventional reference materials to the experimental inoculants C and E containing 3 and 4% Sb, respectively in addition to Ca, Al, Zr, and Mn.
  • the objective of nodulariser B and inoculants C and E was to investigate the pearlite promoting effects for Sb-bearing nodulariser and inoculant alloys.
  • ferritic reference irons No. 1 and 2 contain only 4% pearlite for the low Mn-content of 0.18% and in the 20 mm section plate.
  • the experimental 0.8% antimony bearing nodulariser B resulted in an increase in pearlite content to 29 and 34% for tests No. 3 and 4, respectively.
  • the Sb-containing nodulariser B and the Sb-containing inoculant C in test No. 5 the resulting pearlite content was increased to 59%.
  • the ferritic/pearlitic reference iron No. 6 contained 29% pearlite for the 0.6%Mn and 0.2%Cu additions in the 20 mm section plate.
  • the experimental 0.8% antimony bearing nodulariser B resulted in an increase in pearlite content to 93% for test No. 7.
  • the Sb-containing inoculant E resulted in an increase in pearlite content to 97% for test No. 8.
  • Sb-containing ferrosilicon based nodulariser and inoculant alloys are useful to increase the pearlite content in ferritic irons of initially only 4% pearlite, towards 30 to 60% pearlite when the alloys are used alone or in combinations.
  • Sb-containing nodularisers and inoculants may be useful to increase the pearlite content in ferritic/pearlitic irons having initially about 30% pearlite towards a fully pearlitic condition of 90 to 100% pearlite.
  • Figures 5 a, 5b and 5c show examples of the microstructure in experimental 20 mm plate castings No. 1, 3, and 5 respectively in Table 11.
  • the residual Sb-content in these castings is increasing from ⁇ 0.003% in the reference iron to 0.014% Sb in iron No. 3 and 0.025% Sb in iron No. 5 (ref. Table 13).
  • Sb-containing ferrosilicon-based nodularisers and inoculants may therefore be useful as means to make higher strength pearlitic grades of ductile iron having a relatively low initial alloying content that would otherwise solidify with predominantly ferritic or ferritic/pearlitic microstructures.
  • the content of Sb in the nodulariser and inoculant alloys may be adjusted in order to achieve the required level of pearlite and consequently the required strength level of the ductile iron casting.
  • Sb-bearing nodularisers and inoculants may also be used either alone or in combination to obtain the desired effects.
  • Table 14 Composition of experimental ferrosilicon-based nodularisers.
  • Table 15 Composition of experimental ferrosilicon-based inoculants.
  • MgFeSi nodulariser A is a conventional reference material containing about 6%Mg and l%Ca and RE, while the experimental nodulariser B also contains 0.3% B.
  • Inoculant A is a conventional reference material containing Ca and Al, while the experimental inoculant B is also containing 1% B.
  • the objective of nodulariser B and inoculant B is to find investigate ferrite promoting effects of boron-bearing nodulariser and inoculant alloys.
  • Table 16 shows that the pearlitic reference iron No. 1 contains 96% pearlite for the 0.7%Mn and 0.7%Cu additions in the 20 mm section plate.
  • the experimental 1% boron containing inoculant B resulted in a reduction in pearlite content to 70% for test No. 2, while the experimental 0.3% boron bearing nodulariser B resulted in a reduction in pearlite content to 66% for test No. 3.
  • FIG. 6a, 6b, and 6c shows examples of the microstructure in experimental castings No. 1, 2, and 3 respectively in Table 16.
  • the residual B-content in these castings is ⁇ 5 ppm for the reference iron No. 1, 15 ppm for iron No. 2, and 20 ppm for iron No. 3 (ref. Table 16).
  • Boron-containing ferrosilicon-based nodularisers and inoculants may therefore be useful as means to soften higher strength pearlitic grades of ductile iron that would otherwise solidify with predominantly pearlitic microstructures.
  • the content of boron in the nodulariser and inoculant alloys may be adjusted in order to achieve the required level of ferrite and pearlite and consequently the required strength and ductility levels in the final ductile iron castings.
  • FIG. 7a to 7C show an example of a standardised base iron that is being transformed into different microstructure conditions through late inoculant additions.
  • the ferrosilicon based Reseed ® inoculant (73%Si, l%Ca, 1%A1 and 1.75%Ce) is used as the reference material.
  • the microstructure is found to contain as much as 73% pearlite (and only 27% ferrite), as shown in Figure
  • Nodularisers and inoculants are traditionally used to control the nucleation and growth of the graphite phase in a cast iron microstructure.
  • the modifying agents according to the invention will also enable control of the general matrix microstructure of cast iron materials in order to adjust material properties such as strength, ductility, hardness, machinability and other important properties at a latest possible stage in the foundry processing.

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  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Abstract

L’invention concerne un procédé permettant de contrôler la microstructure d'une fonte, ledit procédé comprenant : la formation d'une fonte ; le prélèvement d'une partie de la fonte ; l’addition d’un inoculant dans la partie prélevée ; et ensuite le coulage de la partie prélevée. L'inoculant comprend un composé modifiant la phase graphite et un composant modifiant la structure de la matrice. Le composant modifiant la structure de la matrice peut être un promoteur de perlite, tel que Sn, Sb ou As, ou un promoteur de ferrite, tel que B.
PCT/NO2005/000022 2004-12-23 2005-01-19 Agents modificateurs pour fonte WO2006068487A1 (fr)

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NO20045611A NO20045611D0 (no) 2004-12-23 2004-12-23 Modifying agents for cast iron

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WO2008076497A1 (fr) * 2006-12-15 2008-06-26 The Dexter Company Fer ductile carbidique brut de coulée
ES2342758A1 (es) * 2008-12-18 2010-07-13 Fagor, S.Coop. Proceso de fabricacion de una fundicion esferoidal.
CN102296226A (zh) * 2011-07-28 2011-12-28 徐州胜海机械制造科技有限公司 大型球墨铸铁件用二次孕育剂及制造方法
WO2014076404A1 (fr) 2012-11-14 2014-05-22 Ferropem Alliage inoculant pour pièces épaisses en fonte
CN104195413A (zh) * 2014-08-18 2014-12-10 成都宏源铸造材料有限公司 一种薄壁急冷件孕育剂及其制备方法和在铸造领域的应用
ES2608934A1 (es) * 2017-02-01 2017-04-17 Fundinorte, S.L. Procedimiento de obtención de fundición nodular
WO2018004357A1 (fr) * 2016-06-30 2018-01-04 Elkem As Inoculant de fonte et procédé de production d'inoculant de fonte
WO2018047134A1 (fr) 2016-09-12 2018-03-15 Snam Alloys Pvt Ltd Procédé sans magnésium pour produire du fer graphitique compacté (cgi)
CN109477154A (zh) * 2016-06-30 2019-03-15 埃尔凯姆公司 铸铁孕育剂和生产铸铁孕育剂的方法
CN109777907A (zh) * 2017-11-14 2019-05-21 济南圣泉集团股份有限公司 包含石墨烯的铸铁孕育剂、其制备方法及使用方法
CN109913741A (zh) * 2017-12-13 2019-06-21 科华控股股份有限公司 一种可消除灰铁铸件过冷石墨的随流孕育剂
NO20172065A1 (en) * 2017-12-29 2019-07-01 Elkem Materials Cast iron inoculant and method for production of cast iron inoculant
NO20172064A1 (en) * 2017-12-29 2019-07-01 Elkem Materials Cast iron inoculant and method for production of cast iron inoculant
NO20172063A1 (en) * 2017-12-29 2019-07-01 Elkem Materials Cast iron inoculant and method for production of cast iron inoculant
NO20172062A1 (en) * 2017-12-29 2019-07-01 Elkem Materials Cast iron inoculant and method for production of cast iron inoculant
WO2020111948A1 (fr) * 2018-11-29 2020-06-04 Elkem Asa Poudre pour moule et revêtement de moule
CN112553395A (zh) * 2020-12-09 2021-03-26 大连瑞谷科技有限公司 保持架生产用球墨铸铁球化处理工艺
ES2804651R1 (es) * 2019-08-08 2021-04-16 Saint Gobain Pam S A Procedimiento de fabricación de un elemento tubular
EP3170578B1 (fr) * 2015-11-17 2021-06-30 GF Casting Solutions Kunshan Co. Ltd. Procédé de fabrication d'une pièce moulée en fonte à graphite sphéroïdal
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2955933A (en) * 1958-11-17 1960-10-11 Union Carbide Corp Inoculants for cast iron
GB2187985A (en) * 1986-03-20 1987-09-23 Fischer Ag Georg Process for the production of pearlitic cast iron
US6102983A (en) * 1997-12-08 2000-08-15 Elkem Asa Cast iron inoculant and method for production of cast iron inoculant
US20040042925A1 (en) * 2002-09-03 2004-03-04 Torbjorn Skaland Method for production of ductile iron

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2955933A (en) * 1958-11-17 1960-10-11 Union Carbide Corp Inoculants for cast iron
GB2187985A (en) * 1986-03-20 1987-09-23 Fischer Ag Georg Process for the production of pearlitic cast iron
US6102983A (en) * 1997-12-08 2000-08-15 Elkem Asa Cast iron inoculant and method for production of cast iron inoculant
US20040042925A1 (en) * 2002-09-03 2004-03-04 Torbjorn Skaland Method for production of ductile iron

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WO2008076497A1 (fr) * 2006-12-15 2008-06-26 The Dexter Company Fer ductile carbidique brut de coulée
US7824605B2 (en) 2006-12-15 2010-11-02 Dexter Foundry, Inc. As-cast carbidic ductile iron
ES2342758A1 (es) * 2008-12-18 2010-07-13 Fagor, S.Coop. Proceso de fabricacion de una fundicion esferoidal.
CN102296226A (zh) * 2011-07-28 2011-12-28 徐州胜海机械制造科技有限公司 大型球墨铸铁件用二次孕育剂及制造方法
WO2014076404A1 (fr) 2012-11-14 2014-05-22 Ferropem Alliage inoculant pour pièces épaisses en fonte
JP2016503460A (ja) * 2012-11-14 2016-02-04 フェロペム 厚肉鋳鉄部品のための接種剤合金
CN104195413A (zh) * 2014-08-18 2014-12-10 成都宏源铸造材料有限公司 一种薄壁急冷件孕育剂及其制备方法和在铸造领域的应用
EP3170578B1 (fr) * 2015-11-17 2021-06-30 GF Casting Solutions Kunshan Co. Ltd. Procédé de fabrication d'une pièce moulée en fonte à graphite sphéroïdal
CN109477153A (zh) * 2016-06-30 2019-03-15 埃尔凯姆公司 铸铁孕育剂和制备铸铁孕育剂的方法
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CN109477154A (zh) * 2016-06-30 2019-03-15 埃尔凯姆公司 铸铁孕育剂和生产铸铁孕育剂的方法
US11098383B2 (en) 2016-06-30 2021-08-24 Elkem Asa Cast iron inoculant and method for production of cast iron inoculant
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US11859270B2 (en) * 2016-09-12 2024-01-02 Snam Alloys Pvt Ltd Non-magnesium process to produce compacted graphite iron (CGI)
WO2018047134A1 (fr) 2016-09-12 2018-03-15 Snam Alloys Pvt Ltd Procédé sans magnésium pour produire du fer graphitique compacté (cgi)
US20210087658A1 (en) * 2016-09-12 2021-03-25 Snam Alloys Pvt Ltd A Non-Magnesium process to produce Compacted Graphite Iron (CGI)
EP3510394A4 (fr) * 2016-09-12 2020-03-18 Snam Alloys Pvt Ltd Procédé sans magnésium pour produire du fer graphitique compacté (cgi)
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