Method for eliminating shrinkage pits and inner shrinkage cavities on surface of cast zinc alloy ingot

Abstract

The invention provides a method for eliminating shrinkage pits and inner shrinkage cavities on the surface of a cast zinc alloy ingot. The method comprises the following steps: when a cast zinc alloy is refined in a holding furnace, a nitrogen stirring and standing slag separation process is adopted; low-speed slagging-off operation is carried out on the surface of the casting zinc alloy liquid; when the zinc alloy is cast, the temperature of a casting mold is controlled to be 80-120 DEG C; and the casting zinc alloy liquid is naturally solidified in the mold along with the operation of the linear casting machine. According to the method for eliminating the surface shrinkage pits and the internal shrinkage cavities of the cast zinc alloy ingot, operation is easy, and the surface shrinkage pits and the internal shrinkage cavities of the cast zinc alloy ingot can be effectively eliminated.

Description

Technical Field

[0001] The invention relates to the technical field of surface control of cast zinc alloy ingots, and in particular to a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of cast zinc alloy ingots. Background Art

[0002] At present, defects such as pitting on the surface of the alloy ingot and internal shrinkage cavities are easy to appear in the casting process of zinc alloy casting. In order to avoid these defects, control processes such as low-temperature casting and surface spray cooling are usually adopted. However, this control process cannot completely eliminate defects such as pitting on the surface of the zinc alloy ingot and internal shrinkage cavities.

[0003] Therefore, there is an urgent need for a method that is simple to operate and can effectively eliminate shrinkage pits on the surface and internal shrinkage cavities of cast zinc alloy ingots. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method which is simple to operate and can effectively eliminate shrinkage pits on the surface and internal shrinkage cavities of a cast zinc alloy ingot.

[0005] In order to solve the above technical problems, the present invention provides a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot, comprising:

[0006] The casting zinc alloy is refined in a holding furnace using a nitrogen stirring and static slag separation process;

[0007] The surface of the zinc alloy casting liquid is subjected to slow slag removal operation;

[0008] When casting zinc alloy, the casting mold temperature is controlled at 80-120℃;

[0009] The cast zinc alloy liquid solidifies naturally in the mold as the linear pouring machine runs.

[0010] Furthermore, the nitrogen stirring during the refining in the holding furnace is to introduce nitrogen into the casting zinc alloy liquid to promote the tumbling of the casting zinc alloy liquid, so that the slag inclusions in the casting zinc alloy liquid escape to the surface of the casting zinc alloy liquid.

[0011] Furthermore, the static slagging during the refining in the holding furnace is to stir the casting zinc alloy liquid with nitrogen and then let the casting zinc alloy liquid stand to allow the slag inclusions in the casting zinc alloy liquid to escape from the casting zinc alloy liquid.

[0012] Furthermore, the nitrogen stirring time is 8-10 minutes, and the slag standing time is 20-30 minutes.

[0013] Furthermore, when the surface of the cast zinc alloy liquid is slowly deslagging, the deslagging is completed once for each cast zinc alloy ingot, and the deslagging time of each cast zinc alloy ingot is controlled within 3-5 seconds.

[0014] Furthermore, the running speed of the linear casting machine is controlled at 35-38 Hz.

[0015] Furthermore, the casting flow rate during casting of the zinc alloy matches the operating speed of the linear casting machine.

[0016] The present invention provides a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot. The process of nitrogen stirring and standing slag separation is adopted when the cast zinc alloy is refined in a holding furnace. The nitrogen stirring process can promote the tumbling of the cast zinc alloy liquid, so that the slag inclusions in the cast zinc alloy liquid can escape to the surface of the cast zinc alloy liquid; and then the standing slag separation process is further adopted to make the slag inclusions in the cast zinc alloy liquid fully escape from the cast zinc alloy liquid; thus, the cast zinc alloy liquid can be fully purified by the nitrogen stirring and standing slag separation process when the cast zinc alloy is refined in a holding furnace, and shrinkage pits on the surface of the cast zinc alloy ingot caused by the enrichment of slag inclusions on the surface of the cast zinc alloy ingot during casting and condensation of the cast zinc alloy.

[0017] Furthermore, the present invention provides a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot, and a slow slag removal operation is adopted on the surface of the cast zinc alloy liquid. The slow slag removal operation can ensure that the surface of the cast zinc alloy liquid is less disturbed during slag removal, thereby ensuring that the cast zinc alloy ingot will not have surface cold shut mark defects due to severe disturbance of the cast zinc alloy liquid during condensation.

[0018] At the same time, the method provided by the present invention for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot is to control the temperature of the casting mold at 80-120°C during casting of the cast zinc alloy, so as to ensure that the cast zinc alloy liquid maintains a certain temperature in the mold during casting, and will not cause the cast zinc alloy liquid to shrink on the surface of the cast zinc alloy ingot due to too low temperature and too fast condensation or too high temperature and slow condensation, thereby forming surface shrinkage pits and internal shrinkage cavities. Moreover, the running speed of the linear casting machine is controlled at 35-38 Hz, and the casting flow rate is matched with the running speed of the linear casting machine, so that the temperature of the cast zinc alloy liquid can be maintained within a certain range, so as to ensure that the cast zinc alloy liquid will not shrink on the surface of the cast zinc alloy ingot due to too low temperature and too fast condensation or too high temperature and slow condensation, thereby forming surface shrinkage pits and internal shrinkage cavities.

[0019] In addition, the present invention provides a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot. The cast zinc alloy liquid solidifies naturally in the mold as the linear pouring machine runs, which can ensure that the cast zinc alloy ingot condenses and eliminates the internal shrinkage cavities. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A control scheme diagram of a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot provided by an embodiment of the present invention;

[0021] Figure 2 This is a surface image of a cast zinc alloy ZX01 ingot produced by the conventional casting control method of this comparative example;

[0022] Figure 3 This is a cross-sectional physical picture of a cast zinc alloy ZX01 ingot produced by casting using the conventional casting control method of this comparative example;

[0023] Figure 4 A surface physical picture of a cast zinc alloy ZX01 ingot produced by casting a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot provided in Example 1 of the present invention;

[0024] Figure 5 A cross-sectional physical picture of a cast zinc alloy ZX01 ingot produced by casting a method for eliminating shrinkage pits on the surface and shrinkage cavities of a cast zinc alloy ingot provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] See also Figure 1 The embodiment of the present invention provides a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot, comprising:

[0026] 1) The process of nitrogen stirring and static slag precipitation is adopted when the cast zinc alloy is refined in the holding furnace.

[0027] Among them, the nitrogen stirring during the refining in the holding furnace is to pass nitrogen into the casting zinc alloy liquid to promote the tumbling of the casting zinc alloy liquid, so that the slag inclusions in the casting zinc alloy liquid escape to the surface of the casting zinc alloy liquid.

[0028] The static slag separation during the refining in the holding furnace is to stir the casting zinc alloy liquid with nitrogen and then let the casting zinc alloy liquid stand to allow the slag inclusions in the casting zinc alloy liquid to escape from the casting zinc alloy liquid.

[0029] When refining the cast zinc alloy in a holding furnace, the nitrogen stirring process can promote the tumbling of the cast zinc alloy liquid, so that the slag in the cast zinc alloy liquid escapes to the surface of the cast zinc alloy liquid. Then, the static slag separation process can be further adopted to make the slag in the cast zinc alloy liquid fully escape from the cast zinc alloy liquid. Through the nitrogen stirring and static slag separation process when refining the cast zinc alloy in a holding furnace, the cast zinc alloy liquid can be fully purified, reducing or eliminating the shrinkage pitting on the surface of the cast zinc alloy ingot caused by the enrichment of slag on the surface of the cast zinc alloy ingot during casting and condensation.

[0030] As a specific implementation of the present invention, the nitrogen stirring time is 8-10 minutes, and the slag separation time is 20-30 minutes.

[0031] 2) Slow slag removal operation is adopted on the surface of the casting zinc alloy liquid.

[0032] Through the slow slag removal operation, it can be ensured that the surface of the casting zinc alloy liquid is less disturbed during slag removal, ensuring that the casting zinc alloy ingot will not have surface cold shut line defects due to the violent disturbance of the casting zinc alloy liquid during condensation.

[0033] As a specific implementation of the present invention, when the surface of the cast zinc alloy liquid is slowly deslagging, each cast zinc alloy ingot is deslagging once, and the deslagging time of each cast zinc alloy ingot is controlled within 3-5 seconds.

[0034] 3) When casting zinc alloy, the casting mold temperature is controlled at 80-120℃.

[0035] Controlling the casting mold temperature at 80-120℃ can ensure that the casting zinc alloy liquid maintains a certain temperature in the mold during casting, and will not cause the casting zinc alloy liquid temperature to be too low and condense too quickly or the temperature to be too high and condense slowly, which will cause the surface of the casting zinc alloy ingot to shrink and form surface shrinkage pits and internal shrinkage holes.

[0036] In addition, by controlling the running speed of the linear pouring machine at 35-38 Hz and matching the casting flow rate with the running speed of the linear pouring machine, the temperature of the cast zinc alloy liquid can also be maintained within a certain range, ensuring that the surface of the cast zinc alloy ingot will not shrink due to the casting zinc alloy liquid temperature being too low and condensing too quickly or the casting zinc alloy liquid temperature being too high and condensing too slowly, thereby preventing the formation of surface shrinkage pits and internal shrinkage cavities.

[0037] 4) The casting zinc alloy liquid solidifies naturally in the mold as the linear pouring machine runs, which can ensure the condensation of the casting zinc alloy ingot and eliminate the internal shrinkage cavity.

[0038] The following is a specific description of a method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot provided by the present invention through comparative examples and embodiments.

[0039] Comparative Example

[0040] In the casting process of the cast zinc alloy, in order to avoid defects such as surface pitting and internal shrinkage cavities of the cast alloy ingot, traditional casting control processes such as low-temperature casting and surface spray cooling are adopted to cast the cast zinc alloy ingot.

[0041] The surface quality and internal shrinkage of ZX01, ZX03, Z18, Z20, Z36 and Z40 type cast zinc alloy ingots produced by the traditional method are shown in Table 1.

[0042] The surface of the cast zinc alloy ZX01 ingot obtained by casting in this comparative example is shown in the figure Figure 2 As shown, the cross-section of the cast zinc alloy ZX01 ingot obtained by casting in this comparative example is shown in Figure 3 shown.

[0043] Example 1

[0044] Step 1: The zinc alloy casting holding furnace adopts a nitrogen stirring + standing slag separation process, wherein the nitrogen stirring: 9 minutes, standing slag separation 25 minutes;

[0045] Step 2: When casting the zinc alloy, the temperature of the casting mold is controlled between 100°C, the speed of the linear casting machine is controlled at 37 Hz, and the casting flow rate matches the running speed of the linear casting machine;

[0046] Step 3: Slow slag removal is performed on the surface of the zinc alloy liquid cast in the casting mold. Each ingot is slag-removed once and the slag-removing speed is controlled within 3-5 seconds.

[0047] Step 4: The cast zinc alloy solidifies naturally in the mold as the linear pouring machine runs, and a qualified cast zinc alloy ingot without surface shrinkage pits and internal shrinkage cavities is obtained.

[0048] The surface quality and internal shrinkage of ZX01, ZX03, Z18, Z20, Z36 and Z40 type cast zinc alloy ingots produced by the method for eliminating shrinkage pits and internal shrinkage cavities on the surface of cast zinc alloy ingots provided in Example 1 of the present invention are shown in Table 1.

[0049] Table 1

[0050]

[0051] A method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot provided in Example 1 of the present invention is shown in the surface of a cast zinc alloy ZX01 ingot obtained by casting. Figure 4 As shown, the cross-section of the cast zinc alloy ZX01 ingot obtained by casting is shown in the method for eliminating shrinkage pits and internal shrinkage cavities on the surface of the cast zinc alloy ingot provided by Example 1 of the present invention. Figure 5 shown.

[0052] from Figure 2 , Figure 3 and Figure 4 , Figure 5 It can be seen from the comparison that the Figure 2 The surface of the ZX01 zinc alloy ingot is obviously pitted by surface shrinkage. Figure 3 The cross section of the cast zinc alloy ZX01 ingot clearly shows internal shrinkage cavities. Figure 4 The surface of the cast zinc alloy ZX01 ingot has no surface shrinkage pitting. Figure 5 There is no shrinkage cavity in the cross section of the cast zinc alloy ZX01 ingot.

[0053] It can be seen from this that the method for eliminating surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot provided by an embodiment of the present invention is not only relatively simple to operate, but also can effectively eliminate surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot.

[0054] Furthermore, it can be seen from the comparison in Table 1 that the method for eliminating surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot provided in an embodiment of the present invention can effectively eliminate surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot.

[0055] Example 2

[0056] Step 1: The zinc alloy casting holding furnace adopts a nitrogen stirring + static slag separation process, wherein the nitrogen is stirred for 10 minutes and the static slag separation is carried out for 30 minutes;

[0057] Step 2: When casting the zinc alloy, the temperature of the casting mold is controlled between 120°C, the speed of the linear casting machine is controlled at 38 Hz, and the casting flow rate matches the running speed of the linear casting machine;

[0058] Step 3: Slow slag removal is performed on the surface of the zinc alloy liquid cast in the casting mold. Each ingot is slag-removed once and the slag-removing speed is controlled within 3-5 seconds.

[0059] Step 4: The cast zinc alloy solidifies naturally in the mold as the linear pouring machine runs, and a qualified cast zinc alloy ingot without surface shrinkage pits and internal shrinkage cavities is obtained.

[0060] The surface quality and internal shrinkage of ZX01, ZX03, Z18, Z20, Z36 and Z40 type cast zinc alloy ingots produced by the method for eliminating shrinkage pits and internal shrinkage cavities on the surface of cast zinc alloy ingots provided in Example 2 of the present invention are shown in Table 1.

[0061] From the comparison in Table 1, it can be seen that the method for eliminating surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot provided in an embodiment of the present invention can effectively eliminate surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot.

[0062] Example 3

[0063] Step 1: The zinc alloy casting holding furnace adopts a nitrogen stirring + static slag separation process, wherein the nitrogen stirring is for 8 minutes and the static slag separation is for 20 minutes;

[0064] Step 2: When casting the zinc alloy, the temperature of the casting mold is controlled between 80°C, the speed of the linear casting machine is controlled at 358 Hz, and the casting flow rate matches the running speed of the linear casting machine;

[0065] Step 3: Slow slag removal is performed on the surface of the zinc alloy liquid cast in the casting mold. Each ingot is slag-removed once and the slag-removing speed is controlled within 3-5 seconds.

[0066] Step 4: The cast zinc alloy solidifies naturally in the mold as the linear pouring machine runs, and a qualified cast zinc alloy ingot without surface shrinkage pits and internal shrinkage cavities is obtained.

[0067] The surface quality and internal shrinkage of ZX01, ZX03, Z18, Z20, Z36 and Z40 type cast zinc alloy ingots produced by the method for eliminating shrinkage pits and internal shrinkage cavities on the surface of cast zinc alloy ingots provided in Example 3 of the present invention are shown in Table 1.

[0068] From the comparison in Table 1, it can be seen that the method for eliminating surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot provided in an embodiment of the present invention can effectively eliminate surface shrinkage pits and internal shrinkage cavities of a cast zinc alloy ingot.

[0069] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot, characterized in that: include: The casting zinc alloy is refined in a holding furnace using a nitrogen stirring and static slag separation process; The surface of the zinc alloy casting liquid is subjected to slow slag removal operation; When casting zinc alloy, the casting mold temperature is controlled at 80-120℃; The cast zinc alloy liquid solidifies naturally in the mold as the linear pouring machine runs.

2. The method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot according to claim 1, characterized in that: The nitrogen stirring during the refining in the holding furnace is to introduce nitrogen into the casting zinc alloy liquid to promote the tumbling of the casting zinc alloy liquid, so that the slag inclusions in the casting zinc alloy liquid escape to the surface of the casting zinc alloy liquid.

3. The method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot according to claim 2, characterized in that: The static slag separation during the refining in the holding furnace is to stir the casting zinc alloy liquid with nitrogen and then let the casting zinc alloy liquid stand so that the slag inclusions in the casting zinc alloy liquid can escape from the casting zinc alloy liquid.

4. The method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot according to claim 3, characterized in that: The nitrogen stirring time is 8-10 minutes, and the slag separation time is 20-30 minutes.

5. The method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot according to claim 1, characterized in that: When the surface of the cast zinc alloy liquid is slowly deslagging, each cast zinc alloy ingot is deslagging once, and the deslagging time of each cast zinc alloy ingot is controlled within 3-5 seconds.

6. The method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot according to claim 1, characterized in that: The linear pouring machine running speed is controlled at 35-38 Hz.

7. The method for eliminating shrinkage pits and internal shrinkage cavities on the surface of a cast zinc alloy ingot according to claim 6, characterized in that: The casting flow rate during casting of the zinc alloy matches the running speed of the linear casting machine.

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