Classifications

• • 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
  • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
  • C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
• • 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

Definitions

• a cored wire which consists of a sheath made of iron material and a filling of fine-grained magnesium master alloy, the latter having a composition of 8 to 15% by weight of magnesium, 42 to 48% by weight of silicon, the remainder essentially iron, the magnesium content, based on the total weight of the cored wire, being at least 5% by weight.
• the amount of cored wire supplied to the cast iron melt, based on the treatment unit, is thus in the order of 0.5 to 1% by weight.
• Fine-grained iron-silicon-magnesium master alloys of the aforementioned type are known for the treatment of cast iron melts, but are only used when working after the pouring process, in which the master alloy is accommodated in the bottom of the ladle and covered with a covering agent in order to avoid the undesirable whirling up to prevent the master alloy from being poured into the ladle and to delay the start of the reaction with the molten cast iron.
• the magnesium yield in this process is of the low order of magnitude customary in practice. The start of the reaction is delayed by the covering agent, but the reaction itself is comparatively violent.
• the magnesium master alloy contained in the cored wire according to the invention can also contain 0.2 to 3.5% by weight of calcium or / and 0.1 to 1.5% by weight of aluminum or / and up to 3% by weight of rare earths that act as metallurgical additives.
• a preferred composition of the filling of the filler wire consists of a magnesium-containing master alloy which consists of 10 to 12% by weight of magnesium, 43 to 46% by weight of silicon, 1 to 2% by weight of rare earths, the rest being iron.
• the sheath of the cored wire can consist of any type of iron, preferably steel.
• the cored wire constructed according to the invention more than tripling the magnesium output is achieved, which has a favorable effect on the mechanical-technological properties of the castings produced. Since the magnesium-containing master alloy can remain free of reaction-inhibiting components, there is inevitably no reaction slag. Another advantage is that the thickness of the sheath of the cored wire can be reduced from 0.4 mm to 0.25 mm, whereby either a smaller diameter of the cored wire can be achieved or a larger amount of magnesium-containing master alloy per unit length can be accommodated in the cored wire . In addition, the relatively large magnesium output leads to a significantly smaller amount of magnesium oxide smoke, which can be extracted without any great technical effort.

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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)

Applications Claiming Priority (2)

Publications (1)

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Citations (5)

• 1990
  • 1990-11-09 DE DE19904035631 patent/DE4035631A1/de not_active Withdrawn
• 1991
  • 1991-10-23 EP EP91118071A patent/EP0484743A1/fr not_active Withdrawn

Patent Citations (5)

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