Composite deoxidizer as well as preparation method and application thereof

Abstract

The invention provides a composite deoxidizer as well as a preparation method and application thereof, and belongs to the technical field of smelting. The composite deoxidizer provided by the invention comprises the following components in percentage by mass: 30-45% of Fe, 5-20% of Fe, 10-25% of CaF, 5-8% of CaO and 6-17% of an auxiliary agent, and the auxiliary agent comprises Ce2O3 and Mg. According to the invention, rare earth oxide dicerium trioxide and Mg are added and can play a synergistic role, so that the deoxidization effect is further improved; by adjusting the component proportion of the composite deoxidizer, the deoxidizing effect of the composite deoxidizer can be improved.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, specifically relating to a composite deoxidizer, its preparation method, and its application. Background Technology

[0002] 0Cr17Ni4Cu4Nb is a precipitation-hardening stainless steel with high strength, hardness, and corrosion resistance. Currently, deoxidizers such as ferrosilicon, ferromanganese, or aluminum are typically added during smelting to purify the molten steel. However, the deoxidation effect is poor, and the molten steel cannot be further purified, failing to meet the inclusion standards for military, nuclear power, and major projects, especially for Class D inclusions, which are generally grade 1.5. Therefore, how to improve deoxidizers to enhance the deoxidation effect of 0Cr17Ni4Cu4Nb stainless steel has become a pressing technical challenge in this field. Summary of the Invention

[0003] The purpose of this invention is to provide a composite deoxidizer, its preparation method, and its application. The composite deoxidizer provided by this invention can improve the deoxidation effect of 0Cr17Ni4Cu4Nb stainless steel.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] The present invention provides a composite deoxidizer comprising the following components in mass percentage: Al 30-45%, Fe 5-20%, CaF 10-25%, CaO 5-8%, and additives 6-17%;

[0006] The additives include Ce2O3 and Mg.

[0007] Preferably, it comprises the following components by mass percentage: Al 35-40%, Fe 6-15%, CaF 15-20%, CaO 6-7%, and additives 8-15%.

[0008] Preferably, the mass ratio of Ce2O3 to Mg is 1:(6-10).

[0009] Preferably, the mass ratio of Ce2O3 to Mg is 1:(7-9).

[0010] This invention also provides a method for preparing the composite deoxidizer described in the above technical solution, comprising:

[0011] A composite deoxidizer is obtained by mixing Al, Fe, CaF, CaO and additives.

[0012] The present invention also provides the application of the composite deoxidizer described in the above technical solution or the composite deoxidizer prepared by the preparation method described in the above technical solution in the purification of molten steel in the smelting of 0Cr17Ni4Cu4Nb.

[0013] Preferably, the composite deoxidizer is added 6 to 15 minutes before tapping the molten steel during the reduction period, when the temperature of the molten steel is 1500 to 1600°C.

[0014] Preferably, the amount of the composite deoxidizer added is 1-5 kg / t.

[0015] Preferably, the composite deoxidizer is added 7-10 minutes before tapping the molten steel during the reduction period.

[0016] Preferably, the temperature of the molten steel is 1520–1580°C when the composite deoxidizer is added.

[0017] This invention provides a composite deoxidizer comprising the following components by mass percentage: 30-45%, Fe 5-20%, CaF 10-25%, CaO 5-8%, and additives 6-17%; the additives include Ce₂O₃ and Mg. This invention, by adding rare earth oxides cerium trioxide and Mg, achieves a synergistic effect, thereby further improving the deoxidation effect; by adjusting the component ratio of the composite deoxidizer, its deoxidation effect can be improved. Experimental results show that the non-metallic inclusion grades of 0Cr17Ni₄Cu₄Nb steel ingots prepared using the composite deoxidizer provided by this invention are: Class A ≤ 1.5, Class B ≤ 1.0, Class C ≤ 1.0, and Class D ≤ 1.0. Detailed Implementation

[0018] The present invention provides a composite deoxidizer comprising the following components in mass percentage: Al 30-45%, Fe 5-20%, CaF 10-25%, CaO 5-8%, and additives 6-17%;

[0019] The additives include Ce2O3 and Mg.

[0020] Unless otherwise specified, the present invention does not have any special limitations on the source of the raw materials used, and commercially available products or well-known preparation methods familiar to those skilled in the art can be used.

[0021] The composite deoxidizer provided by this invention comprises 30-45% Al by mass percentage. As one embodiment, the mass percentage of Al can be 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, or 44%. In this invention, the Al can work in conjunction with other components to further improve the deoxidation effect.

[0022] The composite deoxidizer provided by this invention comprises 5-20% Fe by mass percentage. As one embodiment, the mass percentage of Fe can be 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, or 19%. In this invention, the Fe can work in conjunction with other components to further improve the deoxidation effect.

[0023] The composite deoxidizer provided by this invention comprises 10-25% CaF by mass percentage. As one embodiment, the mass percentage of CaF can be 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, or 24%. In this invention, the CaF can be combined with other components to further improve the deoxidation effect.

[0024] The composite deoxidizer provided by this invention comprises 5-8% CaO by mass percentage. As one embodiment, the mass percentage of CaO can be 5.5%, 6%, 6.5%, 7%, or 7.5%. In this invention, the CaO can be combined with other components to further improve the deoxidation effect.

[0025] The composite deoxidizer provided by this invention comprises 6-17% additives by mass percentage; the additives include Ce₂O₃ and Mg. As one embodiment, the mass percentage of the additives can be 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or 16%. This invention, by adding rare earth oxides cerium trioxide and Mg, achieves a synergistic effect, thereby further improving the deoxidation effect; by adjusting the component ratio of the composite deoxidizer, the deoxidation effect of the composite deoxidizer can be improved.

[0026] The present invention does not have a special limitation on the particle size of Ce2O3, and Ce2O3 known to those skilled in the art can be used.

[0027] In this invention, the preferred mass ratio of Ce₂O₃ to Mg is 1:(6-10). As one embodiment, the mass ratio of Ce₂O₃ to Mg can be 1:7, 1:8, or 1:9. This invention can further improve the deoxidation effect by controlling the mass ratio of Ce₂O₃ to Mg.

[0028] The present invention does not have a special limitation on the particle size of the composite deoxidizer, as long as it contains the above-mentioned components.

[0029] This invention improves the deoxidation effect by adding rare earth oxides cerium trioxide and Mg, which have a synergistic effect; by adjusting the component ratio of the composite deoxidizer, the deoxidation effect of the composite deoxidizer can be improved.

[0030] This invention also provides a method for preparing the composite deoxidizer described in the above technical solution, comprising:

[0031] A composite deoxidizer is obtained by mixing Al, Fe, CaF, CaO and additives.

[0032] The present invention does not have any special limitations on the operation of mixing Al, Fe, CaF, CaO and additives; any technical solution for preparing the mixture well known to those skilled in the art can be used.

[0033] The preparation method provided by this invention is simple.

[0034] The present invention also provides the application of the composite deoxidizer described in the above technical solution or the composite deoxidizer prepared by the preparation method described in the above technical solution in the purification of molten steel in the smelting of 0Cr17Ni4Cu4Nb.

[0035] In this invention, the composite deoxidizer is preferably added 6-15 minutes before tapping during the steel reduction period, when the steel temperature is 1500-1600°C. As one embodiment, the composite deoxidizer can be added 7, 8, 9, 10, 11, 12, 13, or 14 minutes before tapping during the steel reduction period; the steel temperature at the time of addition can be 1510°C, 1520°C, 1530°C, 1540°C, 1550°C, 1560°C, 1570°C, 1580°C, or 1590°C. Adding the composite deoxidizer 6-15 minutes before tapping during the steel reduction period, when the steel temperature is 1500-1600°C, further enhances its deoxidation effect.

[0036] In this invention, the preferred amount of the composite deoxidizer is 1-5 kg / t. As one embodiment, the amount of the composite deoxidizer can be 2 kg / t, 3 kg / t, or 4 kg / t. This invention can further improve the deoxidation effect of the composite deoxidizer by controlling the amount added.

[0037] After the addition of the composite deoxidizer, the present invention preferably uses bottom-blowing argon. The operation of the bottom-blowing argon is not particularly limited in the present invention; any operation well-known in the art can be used. In the present invention, after the addition of the composite deoxidizer, the bottom-blowing argon can increase the volume of inclusions, causing them to float rapidly, removing inclusions, and further purifying the molten steel.

[0038] In one embodiment, the flow rate of the argon gas can be 150 to 200 NL / min.

[0039] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0040] Example 1

[0041] The composite deoxidizer is composed of the following components by mass percentage: Al 45%, Fe 20%, CaF 20%, CaO 8%, and additives 7%.

[0042] The additives are Ce2O3 and Mg;

[0043] The mass ratio of Ce2O3 to Mg is 1:6;

[0044] The preparation method of the composite deoxidizer is as follows:

[0045] A composite deoxidizer is obtained by mixing Al, Fe, CaF, CaO and additives.

[0046] Comparative Example 1

[0047] Based on Example 1, the auxiliary agent was changed to Ce2O3, while other conditions remained unchanged.

[0048] Comparative Example 2

[0049] Based on Example 1, the auxiliary agent was changed to Mg, while other conditions remained unchanged.

[0050] Example 2

[0051] Based on Example 1, the mass ratio of Ce2O3 to Mg was modified to 1:7, while other conditions remained unchanged.

[0052] Example 3

[0053] Based on Example 1, the mass ratio of Ce2O3 to Mg was modified to 1:8, while other conditions remained unchanged.

[0054] Example 4

[0055] Based on Example 1, the mass ratio of Ce2O3 to Mg was modified to 1:9, while other conditions remained unchanged.

[0056] Example 5

[0057] Based on Example 1, the mass ratio of Ce2O3 to Mg was modified to 1:10, while other conditions remained unchanged.

[0058] Comparative Example 3

[0059] Based on Example 1, the mass ratio of Ce2O3 to Mg was modified to 1:3, while other conditions remained unchanged.

[0060] Comparative Example 4

[0061] Based on Example 1, the mass ratio of Ce2O3 to Mg was modified to 1:15, while other conditions remained unchanged.

[0062] Example 6

[0063] The composite deoxidizer is composed of the following components by mass percentage: Al 35%, Fe 15%, CaF 25%, CaO 8%, and additives 17%;

[0064] The additives are Ce2O3 and Mg;

[0065] The mass ratio of Ce2O3 to Mg is 1:8;

[0066] The preparation method of the composite deoxidizer is as follows:

[0067] A composite deoxidizer is obtained by mixing Al, Fe, CaF, CaO and additives.

[0068] Example 7

[0069] The composite deoxidizer is composed of the following components by mass percentage: Al 40%, Fe 20%, CaF 25%, CaO 5%, and additives 10%.

[0070] The additives are Ce2O3 and Mg;

[0071] The mass ratio of Ce2O3 to Mg is 1:9;

[0072] The preparation method of the composite deoxidizer is as follows:

[0073] A composite deoxidizer is obtained by mixing Al, Fe, CaF, CaO and additives.

[0074] The composite deoxidizers prepared in Examples 1-7 and Comparative Examples 1-4 were added 10 minutes before tapping the 0Cr17Ni4Cu4Nb molten steel during the reduction period, at a steel temperature of 1500℃. The amount of composite deoxidizer added was 3 kg / t. After the composite deoxidizer was added, bottom-blowing argon gas was applied at a flow rate of 150 NL / min, followed by casting and cooling to obtain 0Cr17Ni4Cu4Nb steel ingots. The 0Cr17Ni4Cu4Nb steel ingots were inspected for non-metallic inclusions according to GB / T10561.1, and the results are shown in Table 1.

[0075] Table 1 shows the non-metallic inclusion data of 0Cr17Ni4Cu4Nb steel ingots obtained using the composite deoxidizers of Examples 1-7 and Comparative Examples 1-4.

[0076]

[0077]

[0078] As can be seen from Table 1, cerium trioxide and Mg in the composite deoxidizer provided by the present invention can synergistically improve the deoxidation effect; the deoxidation effect can be further improved by controlling the mass ratio of cerium trioxide and Mg.

[0079] As can be seen from the above embodiments and comparative examples, the composite deoxidizer provided by the present invention can improve the deoxidation effect of 0Cr17Ni4Cu4Nb stainless steel.

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A composite deoxidizer, comprising the following components in weight percentage: Al 30-45%, Fe 5-20%, CaF 10-25%, CaO 5-8%, and additives 6-17%; The additives include Ce2O3 and Mg.

2. The composite deoxidizer according to claim 1, characterized in that, It includes the following components by mass percentage: Al 35-40%, Fe 6-15%, CaF 15-20%, CaO 6-7%, and additives 8-15%.

3. The composite deoxidizer according to claim 1, characterized in that, The mass ratio of Ce2O3 to Mg is 1:(6-10).

4. The composite deoxidizer according to claim 1 or 3, characterized in that, The mass ratio of Ce2O3 to Mg is 1:(7-9).

5. A method for preparing the composite deoxidizer according to any one of claims 1 to 4, comprising: A composite deoxidizer is obtained by mixing Al, Fe, CaF, CaO and additives.

6. The application of the composite deoxidizer according to any one of claims 1 to 4 or the composite deoxidizer prepared by the preparation method according to claim 5 in the purification of molten steel in the smelting of 0Cr17Ni4Cu4Nb.

7. The application according to claim 6, characterized in that, The composite deoxidizer is added 6 to 15 minutes before tapping the molten steel during the reduction period, when the temperature of the molten steel is 1500 to 1600°C.

8. The application according to claim 6 or 7, characterized in that, The amount of the composite deoxidizer added is 1-5 kg / t.

9. The application according to claim 7, characterized in that, The composite deoxidizer is added 7-10 minutes before tapping the molten steel during the reduction period.

10. The application according to claim 7, characterized in that, The temperature of the molten steel is 1520–1580°C when the composite deoxidizer is added.

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