CN110252971B

CN110252971B - Novel die casting for blowing argon at bottom of single air brick in casting process

Info

Publication number: CN110252971B
Application number: CN201910624507.7A
Authority: CN
Inventors: 蒋鹏; 钟良才; 郝培锋; 刘国强; 季伟烨; 常胜
Original assignee: Northeastern University China
Current assignee: Northeastern University China
Priority date: 2019-07-11
Filing date: 2019-07-11
Publication date: 2020-09-15
Anticipated expiration: 2039-07-11
Also published as: CN110252971A

Abstract

The invention discloses a new die casting method for blowing argon to the bottom of a single air brick in a casting process. The die casting is carried out by mounting a gas permeable brick on a base plate supporting an ingot mold. The ascending bricks and the air bricks are respectively eccentrically arranged on the chassis at the two sides of the center of the bottom of the ingot mold, the eccentricity of the ascending bricks is A, the eccentricity of the air bricks is B, and A or B is less than 200 mm. The other mode is that the rising brick is still arranged at the center of the bottom of the ingot mould on the base plate, and an annular air brick is adopted and sleeved outside the rising brick. According to the die casting, when the single air brick is adopted for bottom blowing argon in the die casting process, a symmetrical molten steel flow field and a symmetrical temperature field can be formed in the steel ingot die, a solidified shell with uniform thickness is guaranteed to be formed in the solidification process, and the defect of cracks on the surface of the steel ingot is avoided.

Description

Novel die casting for blowing argon at bottom of single air brick in casting process

Technical Field

The invention belongs to the technical field of high-temperature molten steel die casting, and relates to a new die casting for blowing argon at the bottom of a single air brick in the casting process.

Technical Field

With the continuous development of the steel casting process, continuous casting becomes a main production method for casting high-temperature molten steel into a casting blank by modern steel enterprises. But the die casting has significance and value for the survival of the die casting as a traditional cast steel process. At present, the maximum die-cast steel ingot reaches 300-600 t, and the die-cast steel ingot has a compression ratio larger than that of a continuous casting billet, so that the die-cast steel ingot has unique advantages in the production of extra-thick plates and large forgings. The main die-cast product is steel for electric energy such as hydropower, thermal power, wind power, nuclear power station equipment and the like; steel for mines, docks and offshore oil platforms; steel for special-purpose parts such as high-pressure vessels, heavy chemical reaction towers, large machinery, metallurgical equipment and the like; steel for large-sized molds; military steels such as aircraft carriers, tanks and submarines. The die casting steel has high requirements on steel quality due to special purposes, and needs to have good internal quality besides good surface quality, and also needs to have good low-temperature impact property, lamellar tearing resistance, excellent welding property and the like. Therefore, for large steel ingot die casting, measures need to be taken in the pouring process of die casting to improve the cleanliness of molten steel, homogenize the temperature and components of the molten steel, improve the solidification structure of the steel ingot and reduce the segregation and central porosity of the steel ingot. The above object is achieved by a bottom blowing argon technique in a die casting process.

As shown in fig. 1, a conventional rising brick 1 (an inlet of molten steel into an ingot mold) for die casting of a lower pouring method is installed at the center of the ingot mold on a base plate 4; if a single air brick is adopted for bottom argon blowing, the air brick can only be eccentrically arranged and installed; the molten steel in the ingot mould 2 forms an asymmetric flow field due to the eccentric bottom argon blowing of the single air brick, and finally the molten steel generates an asymmetric temperature field. The asymmetric temperature field can cause the molten steel to form an uneven solidified shell on the wall of the steel ingot mold, and crack defects are generated under the action of stress.

Disclosure of Invention

The invention provides a novel die casting and a single air brick bottom argon blowing method in the casting process thereof, aiming at solving the technical problem that when the casting is carried out by the conventional die casting bottom-injection method, the crack defect is easily generated on the uneven solidified shell caused by the asymmetrical flow field and the temperature field formed by the single air brick bottom argon blowing.

The technical scheme of the invention is as follows:

the new die casting method for blowing argon to the bottom of a single air brick in the casting process has two structural modes:

the first structure mode is as follows: the ascending brick 1 and the air brick 4 are eccentrically arranged on a chassis 3 supporting the ingot mould 2 and are respectively arranged on two sides; the eccentricity of the air brick 4 from the bottom center of the steel ingot mold 2 on the chassis 3 is A, and the eccentricity of the lifting brick 1 from the bottom center of the steel ingot mold 2 on the chassis 3 is B; wherein, A or B is less than 200 mm.

The second structure mode is as follows:

the rising brick 1 is arranged at the center of the bottom of the ingot mould 2 on the base plate 3, and the annular air brick 5 is sleeved outside the rising brick 1.

The invention has the advantages that when the single air brick is adopted for die casting and bottom blowing argon, symmetrical molten steel flow fields and temperature fields can be formed, a solidified shell with uniform thickness is ensured to be formed in the solidification process, and the defect of cracks on the surface of a steel ingot is avoided.

Drawings

Fig. 1 is a schematic view of a conventional die cast down-cast riser brick in a tray arrangement.

FIG. 2 is a schematic view of the eccentric arrangement of the rising brick and the air brick when the single air brick is adopted for bottom blowing.

FIG. 3 is a schematic view of the installation of the ascending brick and the air brick when the single-ring air brick is adopted for bottom blowing.

In the figure: 1, lifting the brick; 2, an ingot mould; 3, a chassis; 4, air bricks; 5, annular air brick.

Detailed Description

Example 1 as shown in fig. 2, the present invention employs a truncated cone-shaped air brick 4 having a small upper part and a large lower part, wherein the diameter of the upper part of the air brick 4 is 100mm, the diameter of the lower part is 120mm, and the height is 300 mm. The air brick 4 is installed on the chassis 4 apart from one side of the center of the bottom of the ingot mold 3, the eccentricity A is 90mm, the rising brick 1 is installed on the chassis 4 apart from the other side of the center of the bottom of the ingot mold 3, the eccentricity B is 70mm, and argon is blown during casting.

Example 2 as shown in fig. 2, the present invention employs a rectangular air brick 4 having a small upper part and a large lower part, wherein the upper part of the air brick 4 has a size of 100mm × 200mm, and the lower part has a diameter of 120mm × 200mm and a height of 300 mm. The air brick 4 is installed on the chassis 4 apart from the bottom center one side of ingot mould 3, and eccentricity a equals 90mm, rises brick 1 and installs on the chassis 4 apart from the bottom center opposite side of ingot mould 3, and eccentricity B equals 80mm, blows argon when casting.

Embodiment 3 as shown in fig. 3, the present invention employs an annular air brick 5, wherein the annular inner diameter of the upper portion of the air brick 5 is 160mm, the annular outer diameter is 240mm, the annular inner diameter of the lower portion is 160mm, the annular outer diameter is 260mm, and the height is 300 mm. The air brick 5 is sleeved outside the ascending brick 1 and argon is blown during casting.

Claims

1. The new die casting for blowing argon at the bottom of a single air brick in the casting process is characterized in that a rising brick (1) and an air brick (4) are eccentrically arranged on a base plate (3) for supporting an ingot mold (2) and are respectively arranged at two sides; the eccentricity of the air brick (4) from the bottom center of the ingot mold (2) on the chassis (3) is A, and the eccentricity of the lifting brick (1) from the bottom center of the ingot mold (2) on the chassis (3) is B; wherein, A or B is less than 200 mm.