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Publication numberUS3001869 A
Publication typeGrant
Publication dateSep 26, 1961
Filing dateAug 7, 1959
Priority dateAug 7, 1959
Publication numberUS 3001869 A, US 3001869A, US-A-3001869, US3001869 A, US3001869A
InventorsWilliam G Longstreth, Royal A Van Patten
Original AssigneeFord Motor Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Nodular iron manufacture
US 3001869 A
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Description  (OCR text may contain errors)

United States Patent 3,001,869 NODULAR RON MANUFACTURE William G. Longstreth, Pontiac, and Royal A. Van Patten, Dearborn, Mich., assignors to Ford Motor Company, Dearborn, Mich., a corporation of Delaware No Drawing. Filed Aug. 7, 1959, Ser. No. 832,142 3 Claims. (Cl. 75130) This invention relates to the siderurgical arts and more particularly to that portion of the ferrous technology relating to the production of nodular cast iron. This invention is especially concerned with a process for the conservation and more eflicient and reliable utilization of the nodularizing adjuvants.

In current practice, a cast iron base metal of the proper chemistry is rendered nodular by the addition of a small amount of magnesium. The actual addition of magnesium to molten cast iron is complicated by the fact that magnesium exhibits at molten iron pouring temperatures a vapor pressure far in excess of atmospheric pressure. Magnesium is highly flammable and this fact coupled with its volatility render it an extremely fugacious additive from the view point of the iron founder.

In an effort to circumvent this evanescent characteristic of magnesium, the art has had recourse to the addition of magnesium to the molten iron in the form of an alloy containing about eight percent magnesium alloyed with about forty percent silicon and the remainder iron. Even with this comparatively dilute magnesium alloy, the recoveries are undependable and average only about fifteen percent of theory.

We have discovered that this very low yield of magnesium can be at least doubled by the use of a very simple and effective expedient without altering the foundry operation objectionably. This result is obtained by adding the magnesium metal to a ladle prior to the filling of the ladle with molten cast iron, and protecting this magnesium metal by at least partially covering it with a layer of ferrous metal. The composition, mass and temperature of this protecting mass of ferrous metal is not critical as long as objectionable alloys are not introduced, and the mass of the ferrous metal and its temperature are so regulated that the thermal inertia of the ferrous metal is adequate to provide a temporary protection to the magnesium metal. It is to be understood that a cold layer of ferrous metal will provide the maximum protection with the least mass, and that the mass must be increased if the ferrous metal is added hot or permitted to long remain in the hot ladle prior to the addition of the molten cast iron.

The layer of magnesium metal may be added to the empty ladle, or a portion of the ferrous protecting metal may be first added followed by the magnesium metal and finally the remainder of the ferrous protecting metal.

A typical example of the execution of this invention may be outlined as follows. A ladle capable of containing six hundred pounds of metal is preheated and an addition of one hundred and sixteen grams of magnesium clippings is made directly into the empty ladle. The magnesium clippings are covered by an addition of seven percent of steel punchings about one-eighth inch thick. On the basis of a six hundred pound heat, the steel punchings would weigh forty-two pounds. The analysis of the base metal is a conventional one for nodular iron and contains about 3.9 percent carbon and 2.0 percent silicon. This charge is heated to 28-00 F. in an electric furnace and then poured promptly into the prepared ladle containing the magnesium clippings and the protecting mass of steel punchings.

The solution of the magnesium in the molten iron was prompt and substantially devoid of pyrotechnics and violent reactions. The product was poured into chill blocks and appeared to be satisfactorily nodular.

The term metallic magnesium as used herein is intended to include alloys of magnesium sufdciently rich in this metal to be hazardous for direct addition to molten iron, as well as pure metallic magnesium.

We claim:

1. The process of imparting a nodularizing addition of magnesium to a cast iron base metal comprising placing within a ladle a layer of metallic magnesium, superimposing upon this layer of metallic magnesium a layer of ferrous metal at a temperature substantially below the temperature of molten cast iron, and pouring molten cast iron base metal into the ladle.

2. The process of imparting a nodularizing addition of magnesium to a cast iron base metal comprising placing within a ladle a layer of ferrous metal at a temperature substantially below the temperature of molten cast iron, superimposing upon this layer of ferrous metal a layer of metallic magnesium, superimposing upon this layer of metallic magnesium a further layer of ferrous metal at a temperature below the temperature of molten cast iron, and pouring molten cast iron base metal into the ladle.

3. The process of imparting a nodularizing addition of magnesium to a cast iron base metal comprising placing within a ladle a layer of metallic magnesium, superimposing upon this layer of metallic magnesium a layer of ferrous metal having suflicient mass and sufliciently low temperature to protect the metallic magnesium from excessive loss from the ladle, and pouring molten cast iron base metal into the ladle.

References Cited in the file of this patent UNITED STATES PATENTS 1,922,037 Hard Aug. 15, 1933

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1922037 *Jun 28, 1930Aug 15, 1933Hardy Metallurg CompanyTreatment of metals
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3642466 *Nov 26, 1968Feb 15, 1972Mccaulay James LMethod for the production of cast iron
US3765876 *Nov 1, 1972Oct 16, 1973W MooreMethod of making nodular iron castings
US3833361 *Feb 9, 1971Sep 3, 1974Kusaka Rare Metal Prod Co LtdMethod for adding special elements to molten pig iron
US7156225Feb 22, 2005Jan 2, 2007American Air Liquide, Inc.Reduced moisture compositions comprising an acid gas and a matrix gas, articles of manufacture comprising said compositions, and processes for manufacturing same
US7229667Feb 22, 2005Jun 12, 2007American Air Liquide, Inc.Reduced moisture compositions comprising an acid gas and a matrix gas, articles of manufacture comprising said compositions, and processes for manufacturing same
US7794841Jun 28, 2005Sep 14, 2010American Air Liquide, Inc.Articles of manufacture containing increased stability low concentration gases and methods of making and using the same
US7799150Jan 11, 2007Sep 21, 2010American Air Liquide, Inc.Container for increasing the shelf life of reactive nitrous oxide or nitric oxide gas with an internal metal surface that has been passivated by an oxidized silicon compound that has been exposed to a high concentration of the reactive gas before being filled with a much lower concentration of the gas
US7832550Apr 25, 2005Nov 16, 2010American Air Liquide, Inc.Reactive gases with concentrations of increased stability and processes for manufacturing same
US7837806Jan 13, 2009Nov 23, 2010American Air Liquide, Inc.Making a storage stable acid gas standard for use in detectors and calibration of measurements of this regulated pollutant; reacting a silane compound with an oxygen compound on a metal container to form passivation coating
US7850790Apr 1, 2009Dec 14, 2010American Air Liquide, Inc.Passivating internal metal surfaces of pipes, piping manifold, tubes to increase shelf-life of gas compositions, especially low concentration gas products; passivation coatings made from reacting a silane compound with oxygen to improve storage stability
US8288161Oct 26, 2010Oct 16, 2012American Air Liquide, Inc.Articles of manufacture containing increased stability low concentration gases and methods of making and using the same
WO1990005114A1 *Sep 15, 1989May 17, 1990Gaf Chemicals CorpProcess for removal of soluble platinum group metal catalysts from liquid product mixtures
Classifications
U.S. Classification420/20, 75/568, 428/682, 428/576
International ClassificationC21C1/10, C21C1/08
Cooperative ClassificationC21C1/08, C21C1/10
European ClassificationC21C1/08, C21C1/10