CN116352067A

CN116352067A - Molten iron transfer system and transfer method

Info

Publication number: CN116352067A
Application number: CN202310351283.3A
Authority: CN
Inventors: 纪永杰; 孔德州; 郑斌; 陈世光; 刘伟; 徐超
Original assignee: Guoming Ductile Iron Pipes Co Ltd
Current assignee: Guoming Ductile Iron Pipes Co Ltd
Priority date: 2023-04-04
Filing date: 2023-04-04
Publication date: 2023-06-30

Abstract

The molten iron transfer system comprises a pouring ladle transfer trolley (20) which runs between a casting solution distribution station and a pouring station, wherein a movable support (21) and a nodulizer conveying piece (22) are arranged on the pouring ladle transfer trolley (20), and the nodulizer conveying piece (22) is arranged on the movable support (21) and is close to or far from a pouring ladle (30) through the movable support (21). In the process of transferring the pouring ladle (30) by the pouring ladle transferring trolley (20), or in the time from the moment when the pouring ladle transferring trolley (20) transfers the pouring ladle (30) to the pouring station to the moment when the spheroidal graphite cast iron molten iron raw materials begin to be poured, the spheroidal graphite cast iron molten iron raw materials in the pouring ladle (30) are spheroidized by the moving and conveying operations of the moving bracket (21) and the spheroidizing agent conveying part (22), so that the range of spheroidizing time is widened, the operation is simple and convenient, the control is flexible, the spheroidizing effect is good, and the application range is wide.

Description

Molten iron transfer system and transfer method

Technical Field

The utility model relates to the technical field of ductile iron casting production, in particular to a molten iron transfer system and a transfer method, which can be particularly used for centrifugally casting a single-layer pipe or a multi-metal composite pipe of a ductile iron pipe.

Background

When the spheroidal graphite cast iron pipe is centrifugally cast, the spheroidal graphite cast iron molten iron raw material which is well spheroidized is transported to a casting mould for casting, and casting delay is caused by uncontrollable conditions in the molten iron transportation and casting waiting process, so that the time from the receiving of the spheroidal graphite cast iron molten iron raw material by a casting ladle to the actual start of casting is longer, and the spheroidized molten iron raw material has the problems of spheroidization decline, superscalar magnesium slag of the molten iron raw material and the like, thereby influencing the spheroidization effect and the internal quality of the spheroidal graphite cast iron pipe. The last spheroidizing process such as a spheroidizing process by blowing is adopted in the casting mold to make up for the defects, for example, a novel hot die centrifugal ductile iron pipe molten iron spheroidizing device is disclosed in Chinese patent No. 208840460U, namely, the spheroidizing agent is blown into the pipe mold, but special auxiliary operation of blowing equipment is required for the operation, the technical requirement on the casting operation is higher, although other means for implementing spheroidization in the casting mold are also disclosed in the literature, some additional operations are finally carried out on the casting mold, and if the manufactured product is not a single-layer pipe but a multi-metal composite pipe, a plurality of means are not used.

Disclosure of Invention

In order to solve the problems in the background technology, the utility model seeks breakthrough from the link of molten iron transfer, provides a molten iron transfer system and a transfer method, successfully solves the control difficulty of the spheroidizing time through the spheroidizing of the molten iron on the ladle transfer trolley, widens the selection range of the spheroidizing time, has simpler and more convenient operation, more flexible control, better spheroidizing effect and wider application range.

The technical scheme of the utility model is as follows:

a molten iron transfer system comprising a ladle transfer trolley operating between a casting solution distribution station having a ladle of ductile iron and a casting station having a casting mold; the pouring ladle transferring trolley bears a pouring ladle, receives the ductile iron molten iron raw materials at the casting liquid distribution station, conveys the pouring ladle to the pouring station and controls the pouring ladle to pour the ductile iron molten iron raw materials into a pouring mold;

the casting ladle transferring trolley is provided with a movable support and a spheroidizing agent conveying piece, the spheroidizing agent conveying piece is arranged on the movable support and is close to or far away from the casting ladle through the movable support, the casting ladle transferring trolley is used for transferring the casting ladle, or the casting ladle transferring trolley is used for transferring the casting ladle to a casting station and then to a time before casting of the spheroidal graphite cast iron molten iron raw material, and the spheroidal graphite cast iron molten iron raw material in the casting ladle is spheroidized through the movement and conveying operation of the movable support and the spheroidizing agent conveying piece.

According to the molten iron transfer system, the movable support is the column beam type support capable of moving along the front-back direction of the pouring ladle transfer trolley, and the nodulizer conveying piece is the nodulizing container capable of moving along the up-down direction of the column beam type support.

In the molten iron transfer system, the pouring die is a centrifugal casting pipe die and is provided with a pouring opening facing the pouring ladle.

A molten iron transfer system as described above, the ladle is a single-chamber ladle having a first pour tube in a lower portion thereof capable of being aligned with the pour spout of the casting mold.

In the molten iron transfer system, the pouring ladle is a multi-cavity pouring ladle, and the lower part of the pouring ladle is provided with a first pouring pipe and a second pouring pipe which can be aligned with the pouring gate of the pouring mould by adjusting the direction.

According to the molten iron transfer system, the adjustment direction is achieved by rotating the ladle at a certain angle on the rotating carrier of the ladle transfer trolley.

A molten iron transferring method using the molten iron transferring system as described above, comprising the steps of:

s1, carrying a pouring ladle by the pouring ladle transfer trolley, receiving spheroidal graphite cast iron molten iron raw materials distributed by a spheroidal graphite cast iron molten iron raw material ladle at the casting liquid distribution station and transferring to the pouring station;

s2, in the process of transferring the pouring ladle by the pouring ladle transfer trolley, or after the pouring ladle is transferred to the pouring station by the pouring ladle transfer trolley and before the casting of the ductile iron molten iron raw material, the spheroidizing agent conveying part is conveyed to the upper part of the pouring ladle by the forward movement of the movable bracket, and the spheroidizing agent is conveyed downwards by the spheroidizing agent conveying part to spheroidize the ductile iron molten iron raw material in the pouring ladle;

and S3, reaching the pouring time, controlling the pouring ladle by the pouring ladle transfer trolley to enable the first pouring pipe of the pouring ladle to pour the spheroidal graphite cast iron molten iron raw material into the pouring mould through the pouring opening of the pouring mould, filling the cavity with the spheroidal graphite cast iron molten iron raw material under the action of centrifugal force, and cooling and solidifying to obtain the spheroidal graphite cast iron casting.

The molten iron transferring method utilizing the molten iron transferring system is applied to manufacturing a composite layer casting with an outer layer made of ductile iron, and comprises the following steps:

s1, the pouring ladle transfer trolley bears a pouring ladle, receives spheroidal graphite cast iron molten iron raw materials distributed by a spheroidal graphite cast iron molten iron raw material ladle from a first containing cavity of the pouring ladle at the casting liquid distribution station, receives composite layer metal raw materials distributed by a composite layer metal raw material ladle from a second containing cavity of the pouring ladle and transfers the materials to the pouring station;

s2, in the process of transferring the pouring ladle by the pouring ladle transferring trolley, or after the pouring ladle is transferred to the pouring station by the pouring ladle transferring trolley and before the casting of the ductile iron molten iron raw material, the spheroidizing agent conveying part is conveyed to the position above the first accommodating cavity of the pouring ladle by the forward movement of the movable bracket, and the spheroidizing agent is conveyed downwards by the spheroidizing agent conveying part to spheroidize the ductile iron molten iron raw material in the first accommodating cavity of the pouring ladle;

s3, reaching the pouring time of the ductile iron molten iron raw material, controlling a pouring ladle by the pouring ladle transfer trolley to enable a first pouring pipe of the first containing cavity to pour the ductile iron molten iron raw material into the pouring mould through a pouring port of the pouring mould, filling a cavity with the ductile iron molten iron raw material under the action of centrifugal force, and starting the cooling and solidifying process;

and S4, the pouring time of the composite layer metal raw material is reached, the pouring ladle transfer trolley controls the pouring ladle with the direction adjusted by the rotary carrying platform to enable the second pouring pipe of the second containing cavity to pour the composite layer metal raw material into the pouring mould through the pouring opening of the pouring mould, the composite layer metal raw material is compounded into the formed inner layer of the nodular cast iron under the action of centrifugal force, and the composite layer casting with the outer layer of nodular cast iron material is obtained through cooling and solidification.

The molten iron transferring method utilizing the molten iron transferring system is applied to manufacturing a composite layer casting with an inner layer made of ductile iron, and comprises the following steps:

s2, in the process of transferring the pouring ladle (30) by the pouring ladle transferring trolley (20), or after the pouring ladle is transferred to the pouring station by the pouring ladle transferring trolley, before the composite layer metal raw material is poured, or after the pouring ladle is controlled by the pouring ladle transferring trolley to enable the second pouring tube of the second containing cavity to pour the composite layer metal raw material into the pouring mould until the spheroidal graphite cast iron raw material is poured, the spheroidal graphite cast iron raw material in the first containing cavity of the pouring ladle is spheroidized by the spheroidizing agent conveying piece which is conveyed downwards by the spheroidizing agent conveying piece, and the spheroidal graphite cast iron raw material in the first containing cavity of the pouring ladle is sent forward by the moving bracket;

and S3, reaching the pouring time of the ductile iron molten iron raw material, controlling the pouring ladle with the direction adjusted by the rotary carrier by the pouring ladle transfer trolley to enable the first pouring pipe of the first accommodating cavity to pour the ductile iron molten iron raw material into the pouring mould through the pouring opening of the pouring mould, compositing the ductile iron molten iron raw material into the formed composite layer metal inner layer under the action of centrifugal force, and cooling and solidifying to obtain the composite layer casting with the ductile iron inner layer.

In the molten iron transferring method, before the pouring ladle is adjusted in direction on the rotary carrier, the movable support moves back to the original position with the nodulizer conveying member.

The utility model has the beneficial effects that:

the molten iron transfer system and the transfer method provided by the utility model seek breakthrough from the link of molten iron transfer, successfully solve the control problem of the spheroidizing time through the spheroidizing of the molten iron on the ladle transfer trolley, widen the selection range of the spheroidizing time, can avoid unnecessary quality problems caused by improper spheroidizing time, can be applied to centrifugal casting of spheroidal graphite cast iron pipes, and particularly can be applied to centrifugal casting of spheroidal graphite cast iron multi-metal composite pipes.

According to the molten iron transfer system and the transfer method, the final step of spheroidization of molten iron is performed on the ladle transfer trolley, so that the spheroidization operation is simpler and more convenient than that in a casting mould, the operation time and time control are more flexible, the spheroidization is more uniform, and the effect is better.

Drawings

The aspects and advantages of the present application will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the utility model.

In the drawings:

fig. 1 is a schematic diagram illustrating a construction principle of a molten iron transfer system according to embodiment 1 of the present utility model.

Fig. 2 is a schematic structural diagram of a pouring ladle transferring trolley in fig. 1, wherein:

(A) The figure is a front view;

(B) The figure is a side view.

Fig. 3 is a schematic diagram of a molten iron transfer method according to embodiment 1 of the present utility model, in which:

the drawing (A), the drawing (B) and the drawing (C) are three different action states in the molten iron transferring process.

Fig. 4 is a schematic view showing the construction principle of a molten iron transfer system according to embodiments 2 and 3 of the present utility model.

Fig. 5 is a schematic structural diagram of an initial working state of the ladle transferring trolley in fig. 4 (corresponding to example 2).

Fig. 6 is a schematic view showing still another initial operation state structure of the ladle transferring trolley in fig. 4 (corresponding to embodiment 3).

The components represented by the reference numerals in the figures are:

a ductile iron ladle 10;

the casting ladle transferring trolley 20, the movable support 21, the nodulizer conveying member 22, the support driving assembly 23, the lifting driving assembly 24, the travelling wheel assembly 25 and the rotary carrier 26;

a pouring ladle 30, a first pouring tube 31, a first cavity 32, a second cavity 33 and a second pouring tube 34;

casting mold 40.

Detailed Description

Example 1

Referring to fig. 1, a molten iron transfer system includes a ladle transfer carriage 20 that operates between a casting solution distribution station having a ductile iron ladle 10 and a casting station having a casting mold 40. The ladle transferring trolley 20 carries a ladle 30, receives the ductile iron molten iron raw material at the casting liquid distribution station, transports the ladle 30 to the casting station and controls the ladle 30 to pour the ductile iron molten iron raw material into the casting mold 40.

The casting die 40 in this embodiment is a centrifugal casting tube die having a casting opening facing the ladle 30.

Referring to fig. 2, the ladle transferring trolley 20 is provided with a movable support 21 and a spheroidizing agent conveyor 22, wherein the spheroidizing agent conveyor 22 is mounted on the movable support 21 and is close to or far from the ladle 30 through the movable support 21, and spheroidizing is performed on the spheroidal graphite cast iron molten iron raw material in the ladle 30 through the movement and conveying operation of the movable support 21 and the spheroidizing agent conveyor 22 in the process of transferring the ladle 30 by the ladle transferring trolley 20 or in the time from the time when the ladle transferring trolley 20 transfers the ladle 30 to the pouring station to the time when the spheroidal graphite cast iron molten iron raw material starts to be poured.

The present embodiment seeks a breakthrough from the step of transferring molten iron through the above means, solves the control problem of spheroidizing time through the molten iron spheroidization on the ladle transfer trolley 20, widens the spheroidizing time to the process of transferring the ladle 30 by the ladle transfer trolley 20, or avoids unnecessary quality problems caused by improper spheroidizing time in the time from the moment when the ladle transfer trolley 20 transfers the ladle 30 to the pouring station to the moment before the casting of ductile cast iron molten iron raw materials begins.

With continued reference to fig. 2, the movable support 21 of the present embodiment is a beam-type support that can move in the front-rear direction of the ladle transfer carriage 20, and the nodulizer conveying member 22 is a nodulizing container that can move in the up-down direction of the beam-type support, by way of example.

More specifically, the above-mentioned beam-column type support may include two columns slidably disposed at both sides of the ladle transfer carriage 20 and a cross beam supported by the two columns under which the nodulizer conveyor 22 is driven to move up and down by a lifting drive assembly 24 such as a push-pull cylinder through an intermediate slider or directly connected to the nodulizer conveyor 22.

Two stand can be installed through the slide rail in pouring ladle transfer trolley 20 both sides, and two stand back-and-forth movement on the slide rail is driven through arbitrary support drive assembly 23, and arbitrary support drive assembly 23 is motor drive's gear-rack transmission pair for example, and the rack can be fixed at pouring ladle transfer trolley 20 side, and motor and drive gear can be fixed on the stand, as shown in fig. 2.

Through the structure, the motor of the bracket driving assembly 23 is started to enable the movable bracket 21 to slide towards the front of the ladle transfer trolley 20, and after the movable bracket slides to the upper part of the ladle 20, the nodulizing agent conveying piece 22 is pushed downwards by the lifting driving assembly 24 to be immersed into the ladle 20, so that the nodulizing of the ductile iron molten iron raw materials can be started.

The spheroidizer conveyor 22 according to the present utility model, although not excluding a device like a wire feeding (spheroidizing cored wire) into a ladle, preferably employs the aforementioned spheroidizing vessel capable of moving up and down along a beam-type stand, particularly a spheroidizing vessel disclosed in the applicant's chinese patent publication No. CN214193326U or CN214161377U, which has a swirl port with a bent passage provided on the peripheral wall and/or bottom wall of the spheroidizing vessel, with its own stirring effect, and can greatly enhance the spheroidizing efficiency of molten iron in the ladle 20.

It can be seen that the final spheroidization of molten iron by the ladle transfer trolley 20 provided above is simpler and more convenient than the spheroidization operation in the casting mold 40, the operation timing and time control are more flexible, the spheroidization is more uniform, and the effect is better.

A molten iron transferring method using the molten iron transferring system of the present utility model will be further described with reference to fig. 3, in which the ladle 30 is a single-cavity ladle having a first pouring tube 31 at a lower position thereof capable of being aligned with a pouring gate of the pouring mold 40 in the examples of fig. 1 to 3.

Specifically, the molten iron transferring method using the molten iron transferring system of the present embodiment includes the steps of:

s1, the pouring ladle transferring trolley 20 carries a pouring ladle 30, receives the spheroidal graphite cast iron molten iron raw materials distributed by the spheroidal graphite cast iron molten iron raw material ladle 10 at the casting liquid distribution station and transfers the spheroidal graphite cast iron molten iron raw materials to the pouring station.

S2, referring to fig. 3, during the process of transferring the ladle 30 by the ladle transferring trolley 20, or after the ladle transferring trolley 20 transfers the ladle 30 to the casting station and before starting to cast the ductile iron molten iron raw material, the spheroidizing agent transporting member 22 is moved forward (direction shown in fig. 3 (a)) by the moving bracket 21 to above the ladle 30, and the spheroidizing agent is transported downward (direction shown in fig. 3 (B)) by the spheroidizing agent transporting member 22 to spheroidize the ductile iron molten iron raw material in the ladle 30.

S3, reaching the pouring time, the pouring ladle transferring trolley 20 controls the pouring ladle 30 to enable the first pouring tube 31 of the pouring ladle 30 to move towards the pouring opening of the pouring mould 40 (the direction shown in the (C) diagram in FIG. 3), the spheroidal graphite cast iron molten iron raw material is poured into the pouring mould 40 through the pouring opening of the pouring mould 40, the spheroidal graphite cast iron molten iron raw material fills the cavity under the action of centrifugal force, and the spheroidal graphite cast iron casting is obtained through cooling and solidification.

The ductile cast iron casting obtained in this example was a ductile cast iron single-layer tube.

Example 2

The molten iron transfer system and the transfer method of example 1 are examples of applications in manufacturing a ductile iron single layer pipe, and as described above, the molten iron transfer system and the transfer method of the present utility model are particularly suitable for controlling the spheroidization timing of ductile iron molten iron raw materials in manufacturing a ductile iron multi-metal composite pipe.

First, as shown in fig. 4, the ladle 30 for manufacturing the ductile iron multi-metal composite pipe according to the present embodiment is a multi-cavity ladle having a first casting pipe 31 and a second casting pipe 34 which can be aligned with the gates of the casting mold 40 by adjusting the directions in the lower portion. As can be seen in fig. 5, the adjustment direction is achieved by rotating the ladle 30 at an angle on the rotating carriage 26 of the ladle carriage 20.

Two production conditions are met when the ductile iron composite layer casting is manufactured, one is to manufacture the composite layer casting with the ductile iron material as the outer layer, and the other is to manufacture the composite layer casting with the ductile iron material as the inner layer.

The "castings" referred to in this embodiment are all pipe elements.

In this embodiment, first, taking a composite layer casting with a ductile iron outer layer as an example, a molten iron transfer method in the production case is described, specifically, the method includes the steps of:

s1, the pouring ladle transferring trolley 20 bears the pouring ladle 30, receives the spheroidal graphite cast iron molten iron raw materials distributed by the spheroidal graphite cast iron molten iron raw material ladle 10 from the first containing cavity 32 of the pouring ladle 30 at the casting liquid distribution station, receives the compound layer metal raw materials distributed by the compound layer metal raw material ladle 50 from the second containing cavity 33 of the pouring ladle 30, and transfers the compound layer metal raw materials to the pouring station.

The initial operating state of the tundish 30 on the tundish transport trolley 20 after receiving the castable in step S1 is mainly the orientation state, and can be seen in fig. 5.

S2, in the process of transferring the pouring ladle 30 by the pouring ladle transferring trolley 20, or after the pouring ladle 30 is transferred to the pouring station by the pouring ladle transferring trolley 20 and before the casting of the spheroidal graphite cast iron molten iron raw material is started, the spheroidizing agent conveying part 22 is conveyed to the position above the first containing cavity 32 of the pouring ladle 30 by the forward movement of the movable support 21, and the spheroidizing agent is conveyed downwards by the spheroidizing agent conveying part 22, so that the spheroidal graphite cast iron molten iron raw material in the first containing cavity 32 of the pouring ladle 30 is spheroidized.

And S3, reaching the pouring time of the ductile iron molten iron raw material, controlling the pouring ladle transfer trolley 20 to control the pouring ladle 30 to enable the first pouring pipe 31 of the first containing cavity 32 to pour the ductile iron molten iron raw material into the pouring die 40 through the pouring opening of the pouring die 40, filling the cavity with the ductile iron molten iron raw material under the action of centrifugal force, and starting the cooling and solidifying process.

And S4, the pouring time of the composite layer metal raw material is reached, the pouring ladle transfer trolley 20 controls the pouring ladle 30 with the direction adjusted by the rotary carrying table 26 to enable the second pouring tube 34 of the second accommodating cavity 33 to pour the composite layer metal raw material into the pouring mould 40 through the pouring opening of the pouring mould 40, the composite layer metal raw material is compounded into the formed inner layer of the spheroidal graphite cast iron under the action of centrifugal force, and the composite layer casting with the outer layer of the spheroidal graphite cast iron material is obtained through cooling and solidification.

In the above molten iron transfer method, the movable bracket 21 may be moved backward to the original position with the nodulizer conveying member 22 before the ladle 30 is oriented on the rotary stage 26 for convenience of operation. Of course, the distance between the two columns of the movable support 21 in the present utility model can be completely wider than the longest part of the ladle 30 (the straight line part formed by the two pouring pipes), so that the freedom of the movement of both the movable support 21 and the rotary stage 26 is increased.

Example 3

The present embodiment is an illustration of a molten iron transfer method in the production case, based on embodiment 2, taking as an example the production of a composite layer casting with an inner layer made of ductile iron, and specifically includes the steps of:

The initial operating state of the tundish 30 on the tundish transport trolley 20 after receiving the castable in step S1 is mainly the orientation state, and can be seen in fig. 6.

S2, in the process of transferring the pouring ladle (30) by the pouring ladle transferring trolley (20), or after the pouring ladle transferring trolley 20 transfers the pouring ladle 30 to the pouring station, before starting pouring the composite layer metal raw material, or after the pouring ladle transferring trolley 20 starts controlling the pouring ladle 30 to enable the second pouring tube 34 of the second containing cavity 33 to pour the composite layer metal raw material into the pouring mold 40 until the casting of the ductile cast iron molten iron raw material is started, the moving bracket 21 moves forward to send the nodulizer conveying piece 22 to the position above the first containing cavity 32 of the pouring ladle 30, and the nodulizer conveying piece 22 conveys the nodulizer downwards to spheroidize the ductile cast iron molten iron raw material in the first containing cavity 32 of the pouring ladle 30.

And S3, reaching the pouring time of the ductile iron molten iron raw material, controlling the pouring ladle transfer trolley 20 to enable the first pouring tube 31 of the first containing cavity 32 of the pouring ladle 30 with the direction adjusted through the rotary carrying table 26 to pour the ductile iron molten iron raw material into the pouring mould 40 through the pouring opening of the pouring mould 40 by the pouring ladle transfer trolley, compounding the ductile iron molten iron raw material into the formed composite layer metal inner layer under the centrifugal force, and cooling and solidifying to obtain the composite layer casting with the inner layer made of ductile iron.

The timing and freedom of the movement of the movable support 21 and the rotary stage 26 are described in embodiment 2, and will not be described in detail.

It can be seen from this embodiment that if the casting is performed first by using the outer composite layer metal, the final spheroidization of the ductile iron molten iron raw material can be delayed until the composite layer metal raw material is cast into the casting mold 40 by using the molten iron transfer system and transfer method of the present utility model, so that the spheroidization timing is widened to a greater extent, and more sufficient time conditions are provided for the casting process control.

It is to be understood that the "composite layer metal" referred to in the embodiments of the present utility model refers to a metal that is composited with ductile iron, and is not particularly limited except for ductile iron, and is generally applicable to metals that can be composited with ductile iron, preferably but not limited to various corrosion resistant alloys such as stainless steel, nickel-based alloys, and the like.

Claims

1. A molten iron transfer system comprising a ladle transfer trolley (20) operating between a casting solution distribution station having a ductile iron ladle (10) and a casting station having a casting mold (40); the casting ladle transfer trolley (20) is used for bearing a casting ladle (30), receiving ductile iron molten iron raw materials at the casting liquid distribution station, transporting the casting ladle (30) to the casting station and controlling the casting ladle (30) to cast the ductile iron molten iron raw materials into a casting mould (40);

the ladle transfer trolley (20) is provided with a movable support (21) and a spheroidizing agent conveying piece (22), the spheroidizing agent conveying piece (22) is installed on the movable support (21) and is close to or far away from the ladle (30) through the movable support (21), the ladle transfer trolley (20) is used for transferring the ladle (30) in the process, or the ladle transfer trolley (20) is used for transferring the ladle (30) to a pouring station, and then the spheroidal graphite cast iron molten iron raw materials are subjected to spheroidizing operation through the movable support (21) and the spheroidizing agent conveying piece (22) in the time before pouring the spheroidal graphite cast iron molten iron raw materials.

2. A molten iron transfer system according to claim 1, wherein the movable carriage (21) is a beam-type carriage movable in a front-rear direction of the ladle transfer carriage (20), and the nodulizer conveying member (22) is a nodulizing vessel movable in a vertical direction of the beam-type carriage.

3. A molten iron transfer system according to claim 1 or 2, characterized in that the casting mould (40) is a centrifugal casting tube mould having a pouring spout towards the ladle (30).

4. A molten iron transfer system according to claim 3, characterized in that the ladle (30) is a single-chamber ladle having a first pouring tube (31) in a lower position thereof which is alignable with the pouring spout of the pouring mould (40).

5. A molten iron transfer system according to claim 3, characterized in that the ladle (30) is a multichamber ladle having a first casting tube (31) and a second casting tube (34) in a lower position which can be aligned with the pouring gate of the casting mould (40) by adjusting the direction.

6. The molten iron transfer system of claim 5, wherein the direction of adjustment is achieved by rotating the ladle (30) at an angle on a rotating carriage (26) of the ladle transfer carriage (20).

7. A molten iron transfer method using the molten iron transfer system of claim 4, comprising the steps of:

s1, a pouring ladle transferring trolley (20) bears a pouring ladle (30), receives spheroidal graphite cast iron molten iron raw materials distributed by a spheroidal graphite cast iron molten iron raw material ladle (10) at the casting liquid distribution station and transfers the spheroidal graphite cast iron molten iron raw materials to the pouring station;

s2, in the process of transferring the pouring ladle (30) by the pouring ladle transferring trolley (20), or after the pouring ladle (30) is transferred to the pouring station by the pouring ladle transferring trolley (20) and before the casting of the spheroidal graphite cast iron molten iron raw material is started, the spheroidal graphite cast iron molten iron raw material in the pouring ladle (30) is spheroidized by conveying the spheroidizing agent conveying part (22) downwards through the spheroidizing agent conveying part (22) by moving the movable bracket (21) forwards;

s3, reaching the pouring time, controlling the pouring ladle transfer trolley (20) to control the pouring ladle (30) to enable the first pouring pipe (31) of the pouring ladle to pour the spheroidal graphite cast iron molten iron raw material into the pouring die (40) through a pouring opening of the pouring die (40), filling the cavity with the spheroidal graphite cast iron molten iron raw material under the action of centrifugal force, and cooling and solidifying to obtain the spheroidal graphite cast iron casting.

8. A molten iron transferring method using the molten iron transferring system of claim 6, applied to manufacturing a composite layer casting with an outer layer made of ductile iron, comprising the steps of:

s1, a pouring ladle transfer trolley (20) bears a pouring ladle (30), a first containing cavity (32) of the pouring ladle (30) receives spheroidal graphite cast iron molten iron raw materials distributed by a spheroidal graphite cast iron molten iron raw material ladle (10) at the casting liquid distribution station, and a second containing cavity (33) of the pouring ladle (30) receives composite layer metal raw materials distributed by a composite layer metal raw material ladle (50) and transfers the materials to the pouring station;

s2, in the process of transferring the pouring ladle (30) by the pouring ladle transferring trolley (20), or after the pouring ladle (30) is transferred to the pouring station by the pouring ladle transferring trolley (20) and before the casting of the spheroidal graphite cast iron molten iron raw material is started, the spheroidal graphite cast iron molten iron raw material in the first accommodating cavity (32) of the pouring ladle (30) is spheroidized by the spheroidizing agent conveying part (22) which is conveyed to the upper part of the first accommodating cavity (32) of the pouring ladle (30) by the moving bracket (21) which moves forwards;

s3, reaching the pouring time of the ductile iron molten iron raw material, controlling a pouring ladle (30) by the pouring ladle transfer trolley (20) to enable a first pouring pipe (31) of a first containing cavity (32) to pour the ductile iron molten iron raw material into a pouring die (40) through a pouring opening of the pouring die (40), filling a cavity by the ductile iron molten iron raw material under the action of centrifugal force, and starting the cooling and solidifying process;

s4, the pouring time of the composite layer metal raw material is reached, the pouring ladle transfer trolley (20) controls the pouring ladle (30) with the direction adjusted by the rotary carrying table (26) to enable the second pouring tube (34) of the second containing cavity (33) to pour the composite layer metal raw material into the pouring die (40) through the pouring opening of the pouring die (40), the composite layer metal raw material is compounded to the formed spheroidal graphite cast iron inner layer under the centrifugal force effect, and the composite layer casting with the outer layer of spheroidal graphite cast iron material is obtained through cooling and solidification.

9. A molten iron transferring method using the molten iron transferring system of claim 6, applied to manufacturing a composite layer casting with an inner layer made of ductile iron, comprising the steps of:

s2, in the process of transferring the pouring ladle (30) by the pouring ladle transferring trolley (20), or after the pouring ladle (30) is transferred to the pouring station by the pouring ladle transferring trolley (20) and before the composite layer metal raw material is poured, or after the pouring ladle transferring trolley (20) starts to control the pouring ladle (30) to enable the second pouring tube (34) of the second containing cavity (33) to pour the composite layer metal raw material into the pouring mould (40) and before the spheroidal graphite cast iron molten iron raw material is poured, conveying the spheroidizing agent conveying part (22) to the position above the first containing cavity (32) of the pouring ladle (30) by the moving bracket (21), and conveying the spheroidizing agent downwards by the spheroidizing agent conveying part (22), so as to spheroidize the spheroidal graphite cast iron molten iron raw material in the first containing cavity (32) of the pouring ladle (30);

s3, the pouring time of the ductile iron molten iron raw material is reached, the pouring ladle transfer trolley (20) controls the pouring ladle (30) with the direction adjusted by the rotary carrying table (26) to enable the first pouring tube (31) of the first containing cavity (32) to pour the ductile iron molten iron raw material into the pouring die (40) through the pouring opening of the pouring die (40), the ductile iron molten iron raw material is compounded into the formed composite layer metal inner layer under the centrifugal force, and the composite layer casting with the ductile iron inner layer is obtained through cooling and solidification.

10. The molten iron transfer method according to claim 8 or 9, characterized in that the moving carriage (21) moves back to the home position with the nodulizer conveyor (22) before the ladle (30) is oriented on the rotating stage (26).