Classifications

• • 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

Definitions

• ABSTRACT This invention involves a process of preparing a casting.
• the process includes preparing by known techniques a casting in accordance with the composition given below, but not containing the silicon component.
• the casting is brought to a temperature of the order of 1,600C.
• the process continues with incorporation in the melt maintained at this temperature of an additive constituted on the one hand of at least one magnesium halide and on the other hand of powdered calcium.
• the slag is evaporated and the composition of the casting is completed by the addition of silicon.
• This invention also includes a casting having the following composition.
• the present invention relates to an alloyed, malleable casting, particularly an iron casting having a high aluminum content.
• white cast iron is known, which is without graphite and which is naturally hard and difficult to work; it is also difficult to mould.
• Grey cast iron which is richer in carbon, contains free graphite disseminated in the ferrite; it is fluid and may be worked more easily; it is more resistant to attack from chemical agents but offers only fairly low mechanical characteristics.
• alloyed castings are most currently resorted to, particularly nickel castings with spheroidal graphite; however, these castings are more delicate to prepare and are of high cost price.
• Aluminium castings are known which are particularly advantageous due to their high resistance to corrosion, but they do not enable the desired mechanical properties to be obtained. 7
• the invention relates to a new aluminium casting composition which has the advantages of high resistance to corrosion and a much improved mechanical resistance.
• the invention further relates to a process of preparing such a casting.
• the invention has for an object, in the first place, a casting characterised by its chemical composition of the following formula:
• the invention makes it possible to make a casting which has noteworthy physical qualities, a high resistance to corrosion, an agreable polished appearance and which benefits from a cost price much lower than that of nickel castings for equivalent or superior technical qualities and characteristics.
• the invention further has for an object a process of preparing a casting in accordance with the above characteristics, enabling the physical and chemical qualities of the final product obtained to be further improved.
• the process is characterised in that a casting is prepared by known techniques having the above composition, but not containing the silicon'component, this casting is taken to a temperature of the order of l,600C, and there is incorporated in the melt an additive constituted of two parts of at least one magnesium halide and one part of powdered calcium, the melt being completed by addition of silicon after the slag has been evacuated.
• a pig iron is melted in a reverbatory furnace, an electric furnace or a cruible, said pig iron containing in percent (weight):
• the slag is removed from the molten metal by known process.
• the additive added to the melt and maintained at 1,600C is preferably formed of:
• the calcium acts as a nodularizing agent, and the Mg chloride is dissociated, and the Cl so-produced acts to purify the metal, whereas the Mg component is dissolved in the molten metal and helps the carbon to nodularize.
• the Mg fluoride is dissociated and since this reaction is an exothermic one, it raises the metal temperature; the Mg has the same action as above.
• the Mg coming from the additive is mostly destroyed in the process and eliminated with the slag, but its nodularizing action has been completed.
• the addition of silicon in the proportion defined above is preferably effected in the form of an addition of ferrosilicon in the melt after a period of rest of the order of five minutes following the elimination of the slag.
• the casting thus treated has improved characteristics, particularly an excellent resistance to corrosion; it may be easily moulded, machined or polished and conserves its polish in bad weather and in the presence of corrosive chemical agents.
• the casting may be prepared and treated as indicated hereinabove in an electric furnace, reverberatory furnace or crucible.
• the casting according to the invention may be employed for moulding multiple pieces used in industry, building, household equipment, means of transport, and thus has an extremely wide field of application.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
• Treatment Of Steel In Its Molten State (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=9071869

Family Applications (1)

Country Status (13)

Cited By (7)

Citations (11)

• 1971
  • 1971-02-04 FR FR7104920A patent/FR2094917A5/fr not_active Expired
• 1972
  • 1972-02-01 NL NL7201275A patent/NL7201275A/xx unknown
  • 1972-02-02 BE BE778848A patent/BE778848A/xx unknown
  • 1972-02-02 CH CH154372A patent/CH538314A/fr not_active IP Right Cessation
  • 1972-02-02 DE DE19722204898 patent/DE2204898A1/de active Pending
  • 1972-02-03 NO NO268/72*[A patent/NO132804C/no unknown
  • 1972-02-03 BR BR600/72*[A patent/BR7200600D0/pt unknown
  • 1972-02-03 GB GB508472A patent/GB1341144A/en not_active Expired
  • 1972-02-03 CA CA133,924*7A patent/CA959677A/en not_active Expired
  • 1972-02-04 US US223784A patent/US3871868A/en not_active Expired - Lifetime
  • 1972-02-04 IT IT20249/72A patent/IT947322B/it active
  • 1972-02-04 ES ES399493A patent/ES399493A1/es not_active Expired
  • 1972-02-04 DD DD160705A patent/DD97440A5/xx unknown

Patent Citations (11)

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