A gating system for improving the metallurgical quality of magnesium alloy castings

Abstract

The application discloses a pouring system for improving the metallurgical quality of magnesium alloy castings, comprising: a sprue, which is composed of a serpentine sprue with a curved serpentine shape at the upper part and a sheet sprue with a straight line at the lower part. The serpentine sprue is in a curved serpentine shape, which can buffer the magnesium alloy molten metal liquid, make the liquid flow stable without impact force, avoid the rolling damage to the dense oxidation protective film on the surface of the metal liquid, avoid the formation of secondary oxidation slag, provide a basis for the subsequent magnesium alloy molten metal liquid into the casting part solidification forming to improve the metallurgical quality of the magnesium alloy castings, and solve the problem that the prior art can only skim the oxidation slag and magnesium alloy metal liquid but cannot avoid the generation of the oxidation slag.

Description

TECHNICAL FIELD

[0001] The application relates to a pouring system for improving the metallurgical quality of magnesium alloy castings. BACKGROUND

[0002] When the conventional pouring system is used for pouring magnesium alloy molten metal, the flow rate in the sprue is very fast due to the gravitational potential energy of the magnesium alloy melt, and the metal liquid is prone to rolling in the sprue, the rolling metal liquid can damage the dense oxidation protective film on the surface of the metal liquid, the impurities in the alloy liquid are rolled into the alloy melt, and secondary oxidation slag is formed, and the magnesium alloy casting with internal oxidation slag will appear after solidification, resulting in low metallurgical quality and even scrap.

[0003] In a magnesium alloy sand casting step gap type pouring system disclosed in Chinese Patent No. CN107774911A, the magnesium alloy liquid flows into the first horizontal runner from the high pouring gate along the pouring gate straight runner, and the flow rate of the magnesium alloy liquid is slowed down due to the large cross-sectional area of the first horizontal runner, and slag is easily skimmed off. Although the first horizontal runner with a larger cross-sectional area than the pouring gate straight runner is used to skim off the oxidation slag and magnesium alloy metal liquid, the generation of oxidation slag cannot be avoided to improve the metallurgical quality of the magnesium alloy casting. When a medium or large magnesium alloy casting is cast, due to the large amount of magnesium alloy metal liquid, it is difficult to ensure that a small amount of oxidation slag will not solidify into the magnesium alloy casting. SUMMARY

[0004] To solve the above technical problems, the application provides a pouring system for improving the metallurgical quality of magnesium alloy castings.

[0005] The application is achieved by the following technical solutions.

[0006] The application provides a pouring system for improving the metallurgical quality of magnesium alloy castings, which comprises: a straight runner composed of a serpentine straight runner in the upper part and a sheet straight runner in the lower part.

[0007] The serpentine straight runner is three, and a shunt buffer cavity is arranged in the middle part between the serpentine straight runner and the sheet straight runner.

[0008] The serpentine straight runner and the sheet straight runner are distributed in a staggered manner in the shunt buffer cavity.

[0009] It also includes a pouring buffer nest located at the lower part of the sheet straight runner, and a horizontal runner connected with the pouring buffer nest.

[0010] It also includes an inner gate, which is annular and connected tangentially on the horizontal runner, and the inner gate is arranged at the thick part of the casting.

[0011] The casting is connected with the inner gate, and the side riser and the top riser are connected with the casting.

[0012] The inner gate is provided with a column at the top and is connected with the side riser.

[0013] The side riser and the top riser are provided with a communication channel at more than one third of the positions as a point riser gate.

[0014] The beneficial effects of the present application are that the curved serpentine shape of the serpentine straight gate buffers the magnesium alloy molten metal liquid, makes the liquid flow stable without impact force, avoids the rolling damage to the dense oxidation protective film on the surface of the metal liquid, avoids the formation of secondary oxidation slag, provides a basis for the subsequent magnesium alloy molten metal liquid to enter the casting part solidification forming to improve the metallurgical quality of the magnesium alloy casting, and solves the problem that the prior art can only skim the oxidation slag and magnesium alloy metal liquid but cannot avoid the generation of the oxidation slag. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of the present application;

[0016] In the figure: 1-serpentine straight gate; 2-flow distribution buffer cavity; 3-flaky straight gate; 4-pouring buffer nest; 5-inner gate; 6-column; 7-transverse gate; 8-side riser; 9-top riser; 10-casting. DETAILED DESCRIPTION

[0017] The technical solutions of the present application are further described below, but the scope of protection is not limited to the description.

[0018] As shown in the figure. Figure 1

[0019] The present application is a pouring system for improving the metallurgical quality of magnesium alloy castings, comprising:

[0020] The straight gate for the magnesium alloy molten metal liquid to flow in through the pouring cup during casting pouring, and the straight gate is composed of the serpentine straight gate 1 in the upper part in a curved serpentine shape and the flaky straight gate 3 in the lower part in a straight line.

[0021] When the magnesium alloy molten metal liquid enters the serpentine straight gate 1 section of the straight gate, since the serpentine straight gate 1 is in a curved serpentine shape, it buffers the magnesium alloy molten metal liquid, makes the liquid flow stable without impact force, avoids the rolling damage to the dense oxidation protective film on the surface of the metal liquid, avoids the formation of secondary oxidation slag, provides a basis for the subsequent magnesium alloy molten metal liquid to enter the casting 10 part solidification forming to improve the metallurgical quality of the magnesium alloy casting, and solves the problem that the prior art can only skim the oxidation slag and magnesium alloy metal liquid but cannot avoid the generation of the oxidation slag. ​

[0022] The three serpentine sprues 1 are provided with a middle buffer split-flow cavity 2 for buffering, and the metal liquid from the three serpentine sprues 1 is collected in the split-flow cavity 2. The serpentine sprues 1 and the sheet sprue 3 are distributed in a staggered manner in the split-flow cavity 2.

[0023] The pouring buffer recess 4 is further arranged at the lower part of the sheet sprue 3; the cross runner 7 is further connected with the pouring buffer recess 4, and the cross runner 7 is higher than the pouring buffer recess 4. The magnesium alloy metal liquid completes the buffer flow from the serpentine sprue 1, and then flows to the split-flow cavity 2, the sheet sprue 3, the pouring buffer recess 4, and then flows to the cross runner 7.

[0024] The inner gate 5 is further arranged, and the inner gate 5 is annular and tangentially connected with the cross runner 7. The inner gate 5 is arranged at the thick part of the casting, and the specific gravity of the oxide and flux slag generated during smelting and pouring of the magnesium alloy is greater than that of the alloy liquid. The annular inner gate 5 tangentially connected with the cross runner 7 can block the impurities with specific gravity greater than that of the magnesium alloy metal liquid, and further improve the metallurgical quality of the magnesium alloy casting.

[0025] The casting 10 is further connected with the inner gate 5; the side riser 8 and the top riser 9 are further connected with the casting 10. The inner gate 5 is provided with a column 6 at the top and connected with the side riser 8, which is beneficial to the upward floating of the slag gas in the upper part of the cross runner 7 to the riser, and the deposition of the slag and oxide slag with relatively large specific gravity in the lower cross runner 7.

[0026] The side riser 8 and the top riser 9 are provided with a communication channel at more than one third of the positions as a point gate runner, which can reduce the time of metal flowing through the mold, and the point gate pouring makes the temperature of the metal liquid at the upper end of the riser higher than that at the lower part, thereby solving the problem that the pouring and filling direction of the bottom pouring magnesium alloy is inconsistent with the solidification direction of the casting.

Claims

1. A gating system for improving the metallurgical quality of magnesium alloy castings, characterized in that, include: A sprue is composed of a serpentine sprue (1) that is curved and serpentine at the top and a sheet-like sprue (3) that is straight at the bottom; There are three serpentine sprues (1), and a flow-diverting buffer cavity (2) is provided in the middle between the serpentine sprues (1) and the sheet sprues (3) to act as a buffer. The serpentine sprue (1) and the sheet sprue (3) are staggered in the diversion buffer cavity (2); It also includes a pouring buffer cavity (4) located below the sheet-like straight pouring channel (3); and a horizontal pouring channel (7) connected to the pouring buffer cavity (4); It also includes an ingate (5), which is annular and tangentially connected to the runner (7). The ingate (5) is located at the thick part of the casting. It also includes a casting (10) connected to an inner gate (5); it also includes a side riser (8) and a top riser (9) connected to the casting (10); The top of the ingate (5) is equipped with a column (6) which is connected to the side riser (8); The side riser (8) and top riser (9) have a connecting channel at a position of more than one-third as a point riser gating channel.

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