# US 2013/0239751 A1 · Method for producing nodular cast iron

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- Number: US 2013/0239751 A1
- Document ID: US20130239751A1
- Status: Published application
- Kind: A1
- Application number: 13/869,023
- Filed: 2013-04-23
- Published: 2013-09-19
- Earliest claimed: 2010-10-25
- Assignees: Tianjin Wanlu Limited Company of Science and Technology
- Inventors: Nianlu LIU; Changchen LIU
- Web page: https://patentgrep.com/patent/US20130239751A1

## CPC

- C21C 1/105: {Nodularising additive agents}
- B22D 1/00: Treatment of fused masses in the ladle or the supply runners before casting {(for continuous casting B22D11/10; metallurgical processing, e.g. refining of iron or other metal C21, C22, C25C)}
- C21C 1/10: Making spheroidal graphite cast-iron
- C21C: PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22)

## Abstract

A method for producing nodular cast iron by using a nodulizer and a spheroidizing device, the method including spheroidizing, the spheroidizing including the following steps: a) placing an integrated rare earth magnesium ferrosilicon nodulizer coated with a rectangular steel tube at a preset position inside a spheroidizing ladle, disposing a strut head on the spheroidizing ladle, and fixing the strut head; b) inputting a ferrosilicon inoculant into the spheroidizing ladle; c) inputting melted iron into the spheroidizing ladle for spheroidizing; and d) removing the strut head from the spheroidizing ladle after spheroidizing.

## Claims

### Claim 1

A method for producing nodular cast iron by using a nodulizer and a spheroidizing device;
the nodulizer being prepared by providing a rectangular steel tube (13) comprising a pressure regulating through hole (17) arranged on a middle part of a side surface thereof; for the rectangular steel tube, the pressure regulating through hole (17) being arranged on a middle part of an end surface of a relatively small area; injecting an alloy melt of a rare earth magnesium ferrosilicon nodulizer comprising magnesium ≦20%, silicon ≦65%, and Re ≦3% from the pressure regulating through hole (17) into the rectangular steel tube (13) to condense and cool; a diameter of the pressure regulating through hole (17) being 8-14 mm; using a steel plate having a same thickness as a wall of the rectangular steel tube to close a part of an opening of each of two ends of the rectangular steel tube by means of welding for controlling a reaction time and reaction state of the nodulizer;
the spheroidizing device comprising: a strut head (1), a steering shaft (2), a mobile location (3), a pressure lever (4), a balance steel (5), a column and a positioning ruler (6), a first bolt (8), and a third bolt and a nut thereof (12); the strut head (1) being movable and fixable at a required position by using the third bolt and the nut thereof (12) disposed on the column and the positioning ruler (6) as an rotational axis of the pressure lever (4), arranging the steering shaft (2) on the pressure lever (4), and connecting the first bolt (8) of the steering shaft (2) to the strut head (1); a bottom surface of the strut head (1) being flat; a fire-proof material coated on the strut head (1) being a frame welded by a threaded steel and an iron wire; the column and the positioning ruler (6) being welded as a whole body; the mobile location (3) being arranged on an end part of the positioning ruler; the balance steel (5) being hanged on the other end of the pressure lever (4);
the method comprising spheroidizing, and the spheroidizing comprising the following steps:
a) placing an integrated rare earth magnesium ferrosilicon nodulizer (18) coated with the rectangular steel tube at a preset position inside a spheroidizing ladle (7), disposing the strut head (1) on the spheroidizing ladle (7), and fixing the strut head (1);
b) inputting a ferrosilicon inoculant into the spheroidizing ladle (7);
c) inputting melted iron into the spheroidizing ladle (7) for spheroidizing; and
d) removing the strut head (1) from the spheroidizing ladle (7) after the spheroidizing.

### Claim 2 (depends on 1)

The method of claim 1, wherein the rectangular steel tube (3) is a square steel tube.

### Claim 3 (depends on 1)

The method of claim 1, wherein
the alloy melt of the rare earth magnesium ferrosilicon nodulizer is poured into the rectangular steel tube (13); and
the alloy melt is produced by a one-step method for smelting ferrosilicon alloy in a submerged arc furnace or by a remelting method in an electric furnace.

### Claim 4 (depends on 2)

The method of claim 2, wherein
the alloy melt of the rare earth magnesium ferrosilicon nodulizer is poured into the square steel tube (13); and
the alloy melt is produced by a one-step method for smelting ferrosilicon alloy in a submerged arc furnace or by a remelting method in an electric furnace.

### Claim 5 (depends on 1)

The method of claim 1, wherein cooling iron is arranged between a combination of the rectangular or square steel tubes being filled with the alloy melt of the nodulizer.

### Claim 6 (depends on 2)

The method of claim 2, wherein cooling iron is arranged between a combination of the rectangular or square steel tubes being filled with the alloy melt of the nodulizer.

### Claim 7 (depends on 1)

The method of claim 1, wherein the spheroidizing is processed by using an electric motor to drive a lifting device, hanging the strut head (1) provided with a counterweight iron (15) on a hook of the lifting device to substitute the means of using the third bolt and the nut thereof (12) disposed on the column and the positioning ruler (6) as the rotational axis of the pressure lever (4), arranging the steering shaft (2) on the pressure lever (4), and connecting the first bolt (8) of the steering shaft (2) to the strut head (1).

### Claim 8 (depends on 2)

The method of claim 2, wherein after the spheroidizing, an additional nodulizer is supplied by means of using the third bolt and the nut thereof (12) disposed on the column and the positioning ruler (6) as the rotational axis of the pressure lever (4), arranging the steering shaft (2) on the pressure lever (4), and connecting the first bolt (8) of the steering shaft (2) to the strut head (1), the additional integrated rare earth magnesium ferrosilicon nodulizer (18) coated with the rectangular steel tube is bound to the bottom surface of the strut head (1) by an iron wire and an iron sheet, and is pressed down into the iron melt for supplying a required amount of magnesium.

### Claim 9 (depends on 7)

The method of claim 7, wherein after the spheroidizing, an additional nodulizer is supplied by means of using the electric motor to drive the lifting device, hanging the strut head (1) provided with the counterweight iron (15) on the hook of the lifting device, the additional integrated rare earth magnesium ferrosilicon nodulizer (18) coated with the rectangular steel tube is bound to the bottom surface of the strut head (1) by an iron wire and an iron sheet, and is pressed down into the iron melt for supplying a required amount of effective magnesium element.

### Claim 10 (depends on 1)

The method of claim 1, wherein
a positioning shaft sleeve (25) is welded on an upper end of an outer side of the spheroidizing ladle (7) and connected to the strut head (1); an end of a positioning handle (23) is provided with a thread, the thread matches with a nut welded on the positioning shaft sleeve (25); the thread of the end of the positioning handle (23) passes through the positioning shaft sleeve (25) and fastens the strut head (1); and a position of the strut head (1) in the spheroidizing ladle (7) is adjusted by the positioning handle (23);
the strut head (1) is movable and fixable at the required position; the integrated rare earth magnesium ferrosilicon nodulizer (18) coated with the rectangular steel tube or by the square steel tube is fixed beneath the strut head (1); and
the bottom surface of the strut head (1) is flat; the fire-proof material coated on the strut head (1) is a frame welded by a round steel, a steel bar, and the iron wire.

### Claim 11 (depends on 1)

The method of claim 1, wherein
an integrated rare earth magnesium ferrosilicon alloy (21) having a content of rare earth ≦33% and coated with a rectangular or square steel tube is arranged inside an integrated magnesium ferrosilicon nodulizer (20);
a direction of an opening of the integrated magnesium ferrosilicon nodulizer (20) coated with the rectangular or square steel tube is the same as a direction of an opening of the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube;
the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube is bound to a compositely coated rectangular or square steel tube (22) by welding;
an alloy melt of the integrated magnesium ferrosilicon nodulizer (20) is injected into the compositely coated rectangular or square steel tube (22) to condense and cool;
the cooling iron is arranged between the rectangular steel tubes or square steel tubes being filled with the alloy melt of the nodulizer;
the iron melt is input into the spheroidizing ladle (7) for spheroidizing; and
during a later half of the reaction time, the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube participates in the spheroidizing for supplying a required amount of rare earth.

### Claim 12 (depends on 7)

The method of claim 7, wherein
an integrated rare earth magnesium ferrosilicon alloy (21) having a content of rare earth ≦33% and coated with a rectangular or square steel tube is arranged inside an integrated magnesium ferrosilicon nodulizer (20);
a direction of an opening of the integrated magnesium ferrosilicon nodulizer (20) coated with the rectangular or square steel tube is the same as a direction of an opening of the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube;
the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube is bound to a compositely coated rectangular or square steel tube (22) by welding;
an alloy melt of the integrated magnesium ferrosilicon nodulizer (20) is injected into the compositely coated rectangular or square steel tube (22) to condense and cool;
the cooling iron is arranged between the rectangular steel tubes or square steel tubes being filled with the alloy melt of the nodulizer;
the iron melt is input into the spheroidizing ladle (7) for spheroidizing; and
during a later half of the reaction time, the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube participates in the spheroidizing for supplying a required amount of rare earth.

### Claim 13 (depends on 10)

The method of claim 10, wherein
an integrated rare earth magnesium ferrosilicon alloy (21) having a content of rare earth ≦33% and coated with a rectangular or square steel tube is arranged inside an integrated magnesium ferrosilicon nodulizer (20);
a direction of an opening of the integrated magnesium ferrosilicon nodulizer (20) coated with the rectangular or square steel tube is the same as a direction of an opening of the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube;
the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube is bound to a compositely coated rectangular or square steel tube (22) by welding;
an alloy melt of the integrated magnesium ferrosilicon nodulizer (20) is injected into the compositely coated rectangular or square steel tube (22) to condense and cool;
the cooling iron is arranged between the rectangular steel tubes or square steel tubes being filled with the alloy melt of the nodulizer;
the iron melt is input into the spheroidizing ladle (7) for spheroidizing; and
during a later half of the reaction time, the integrated rare earth magnesium ferrosilicon alloy (21) having the content of rare earth ≦33% and coated with the rectangular or square steel tube participates in the spheroidizing for supplying a required amount of rare earth.