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US 4,900,509 AGranted
Process for manufacturing cast iron containing vermicular graphite
AssigneeGeorg Fischer Aktiengesellschaft
InventorsWerner Menk, Urs Brandenberger
Life of this patent
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Abstract
A process for the manufacture of cast iron containing vermicular graphite is described, in which nodular cast iron (GGG) is used as a starting melt. The GGG melt can be produced in a converter in a precise and reproducible way, whereby the sulphur and oxygen contents of the GGG melt are limited within narrow ranges. Additional sulphur is added to the GGG melt in an amount determined by an empirical formula depending on the magnesium and sulphur contents of the GGG melt to produce cast iron containing vermicular graphite (GGV). The GGV is produced by the present process with precision and in a reproducible manner.
Claims10
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- wherein A is about 1.08.
7 more elements
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- wherein B is in the range of about 0.016 to 0.028.
7 more elements
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- wherein the sulphur-containing substance is elemental sulphur.
7 more elements
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- wherein the sulphur-containing substance comprises more than one sulphur material, said sulphur material being selected from the group consisting of elemental sulphur and chemically combined sulphur.
7 more elements
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- further comprising adding to the GGG melt an inoculation agent.
7 more elements
The process of claim 8 wherein the inoculation agent is FeSi75.
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- further comprising preventing the reaction products produced by the addition of the sulphur-containing substance from being introduced into the cast piece by means of a filter.
7 more elements
The process of claim 11 wherein said filter is a ceramic filter.
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- wherein the GGG melt is converted-treated cast iron containing nodular graphite.
7 more elements
A process for the manufacture of cast iron containing vermicular graphite comprising:
- (a) providing a GGG melt;
- and
- (b) adding to said GGG melt a sulphur-containing substance in accordance with the equation:
- S=A.times.Mg-B wherein
- S represents the amount of sulphur in weight percent present in the sulphur containing substance,
- Mg represents the amount of magnesium in weight percent present in the GGG melt,
- A is a factor which depends on the magnesium content of the GGG melt and which is in the range of 0.9 to 1.2, and
- B is a constant which depends on the sulphur content of the GGG melt and which is in the range of about -0.02 to 0.05,
- whereby the ratio of magnesium to sulphur in the resulting melt is in the range of from about 2:1 to 1:1, and
- further comprising adding to said GGG melt a metallic substance selected from the group consisting of cerium, cerium alloy, titanium, calcium, aluminum, zirconium and bismuth.
7 more elements
Dependencies are inferred from the claim text.