CN-121972616-A - Method for improving riser feeding of ingot casting

Abstract

The invention relates to the field of casting, in particular to a method for improving riser feeding of a die-casting steel ingot, which sequentially comprises the steps of 1) determining the size of a riser by adopting digital simulation software, 2) arranging a plurality of inner runners near a hot junction area to enable molten metal to be rapidly injected into the hot junction area, 3) arranging a high-temperature heat dissipation area at the upper part of the riser and a heat preservation area at the lower part of the riser, arranging a heat insulation layer outside the heat preservation area, scattering steel powder of the same steel grade into the liquid level in the riser after casting to enable the surface liquid level to form a solidified shell, and 4) covering a steel plate with the same cross section on the solidified shell, applying a downward pressure F according to the steel grade, and maintaining the pressure until the molten steel in a die cavity is completely solidified. The invention effectively reduces the defects of shrinkage cavity, shrinkage porosity and the like in the casting, and obviously improves the compactness and mechanical property of the casting.

Inventors

• LI DEJUN
• ZHAO LIANG
• JIA JIXIANG
• HUANG YUPING
• YANG JI
• LI BOYANG
• WANG HAIWEI
• SUN SHEN

Assignees

• 鞍钢股份有限公司

Dates

Publication Date

20260505

Application Date

20260209

Claims (6)

1. 1. A method for improving riser feeding of a ingot, comprising, in order: 1) Determining the size of a riser by adopting digital simulation software; 2) A plurality of ingate channels are arranged near the hot junction area, so that molten metal is rapidly injected into the hot junction area; 3) The upper part of the riser is a high-temperature heat dissipation area, the lower part of the riser is a heat preservation area, and a heat insulation layer is arranged outside the heat preservation area; 4) Covering a steel plate with the same cross section on the solidification shell, applying a downward pressure F according to the steel grade, and maintaining the pressure until the molten steel in the die cavity is completely solidified.
2. 2. A method of improving riser feeding of a ingot according to claim 1, wherein step 1) riser sizing rules: the relation between the inner diameter D of the section of the cylindrical riser and the thickness T of the steel ingot is D= (0.5-0.8) T, and the height H= (1.1-1.5) D; the relation between the equivalent inner diameter D of the rectangular riser section and the thickness T of the steel ingot is D= (0.7-1.0) T, the height H= (1.3-1.8) D, and the aspect ratio of the rectangle is (2-5) (5-9).
3. 3. The method for improving riser feeding of a die-casting ingot according to claim 1, wherein in the step 2), a high heat conduction area at the upper part of the riser is made of silicon carbide material, a high aluminum material is used for a heat conduction area at the lower part of the riser, and a ceramic fiber material is used for a heat insulation sleeve.
4. 4. The method for improving riser feeding of a ingot according to claim 1, wherein the pitch of the ingate in the step 2) is 30-50 cm.
5. 5. The method for improving riser feeding of a die-casting steel ingot according to claim 1, wherein the granularity of the steel powder in the step 4) is less than or equal to 0.5mm, and the scattering thickness is 20-50 mm.
6. 6. A method for improving riser feeding of a ingot according to claim 1, wherein step 5) applies the following pressure F: High alloy steel press The unit 1000kgf, e is a natural constant, wherein the value range of t1 is more than or equal to 10 and less than or equal to 180 minutes, and the force F changes along with the time t 1; low alloy steel press The unit is 1000kgf, wherein the value range of t2 is more than or equal to 5 and less than or equal to 150 minutes, and the force F changes along with the time t 2.

Description

Method for improving riser feeding of ingot casting Technical Field The invention belongs to the field of casting, and particularly relates to a method for improving riser feeding of a die-casting steel ingot. Background In the casting process, the riser has the main function of providing extra molten metal when the casting is solidified and contracted so as to compensate the volume reduction of the casting caused by liquid state contraction and solidification and contraction, thereby preventing the defects of shrinkage cavity, shrinkage porosity and the like in the casting and ensuring the quality and performance of the casting. However, the existing die casting riser feeding method has a plurality of defects. For example, conventional riser designs often rely on empirical formulas that do not adequately account for the complex geometry and solidification characteristics of the casting, resulting in excessive or insufficient riser dimensions. The excessively large size not only wastes a large amount of metal materials to reduce the yield of the steel ingot and increase the cost, but also can cause the casting to generate an overheat area near the riser to influence the tissue performance of the casting, and the excessively small size can not provide enough feeding metal liquid to cause the defects of shrinkage cavity, shrinkage porosity and the like in the casting to seriously influence the quality of the casting. In addition, in the conventional feeding process, the flowing path of the molten metal between the riser and the casting is unreasonable, so that the problems of high flowing resistance, untimely feeding and the like are easy to occur, and the feeding effect is further reduced. Therefore, the development of a method capable of accurately and efficiently improving the feeding effect of the die casting riser has important practical significance. The patent with the application number of CN201510186969.7 discloses a casting riser induction heating device and a casting riser induction heating method, the feeding effect of a riser is improved by heating molten steel in the riser through an electromagnetic induction heating coil arranged on the periphery of the riser, the method can ensure that the molten steel in the riser is at a higher temperature and provides favorable conditions for feeding the inside of a steel ingot, but the phenomenon that partial channels of the steel ingot are completely bridged or half bridged in the solidification process is not considered, at the moment, although the riser is provided with certain molten steel and has certain temperature, the feeding channel is not smooth, the molten steel is difficult to feed to a contracted pore, and therefore, the feeding effect is improved to a limited extent by heating the temperature of the molten steel in the riser. The patent with the application number of CN201110292665.0 discloses a medium-frequency electric heating steel billet casting shrinkage cavity compensating device and a process, a casting riser is assembled on the upper part of a steel mould, the riser is pressed by quartz sand mixed sodium silicate, an induction heating coil is sleeved outside the riser, and the riser is connected with a medium-frequency induction heating power distribution cabinet. And after the molten steel is poured and filled, the induction coil is electrified and heated in time, and then the current is gradually reduced, so that the temperature of the molten steel in the riser is reduced at a speed of 100-120 ℃ per minute until solidification is completed. The method can effectively reduce the cooling speed of the riser, so that the feeding effect is improved to a certain extent. However, the phenomenon that part of channels are in complete 'bridging' or 'half bridging' in the solidification process of the steel ingot still exists, and at the moment, although a certain amount of molten steel exists in the riser and has a certain temperature, the feeding channel is not smooth, and the molten steel is difficult to feed to the contracted pore, so that the problem of limited feeding effect is improved by heating the temperature of the molten steel in the riser. Disclosure of Invention The invention aims to solve the technical problem of providing a method for improving the feeding of a casting head of a die casting steel ingot, which is used for obviously improving the feeding effect of the casting head, reducing the residual steel quantity in the casting head, improving the metal yield of the steel ingot, reducing the defects of shrinkage cavity, shrinkage porosity and the like in the casting, improving the quality of the cast ingot and reducing the production cost. In order to achieve the above purpose, the invention adopts the following technical scheme: A method of improving riser feeding of a ingot, comprising, in order: 1) Determining the size of a riser by adopting digital simulation software; 2) A plurality of ingate channels are arranged near