Pouring method of low-density steel and casting blank

Abstract

The invention provides a pouring method and a casting blank of low-density steel, and relates to the technical field of ferrous metallurgy, the pouring method comprises the following steps: controlling molten steel obtained by smelting at a preset temperature to obtain molten steel to be poured; pouring the to-be-poured molten steel from a storage container to a casting mold to complete pouring to obtain a casting blank; in the dumping process, the tipping speed is controlled as follows: in the process that the tipping angle is changed from 0 degree to 60 degrees, the tipping speed is 0.95-1r / min; in the process that the tipping angle is changed from 60 degrees to 75 degrees, the tipping speed is 0.4-0.6 r / min; in the process that the tipping angle is changed from 75 degrees to 95 degrees, the tipping speed is 0.2-0.4 r / min; and in the process that the tipping angle is changed from 95 degrees to 120 degrees, the tipping speed is 0.6-1.0 r / min. The casting blank manufactured through the method is high in uniformity, and then the low-density steel obtained through casting blank machining is high in uniformity.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, and in particular to a casting method and a casting blank of low-density steel. Background Art

[0002] Lightweighting is the future development path of the automotive industry. Lightweighting of automobiles can be achieved in the following two ways: (1) Improving the strength of steel plates, thereby reducing the size of automotive parts. (2) Reducing the density of steel plates. The main means to reduce the density of steel materials is to add low-density elements, such as Al and Mn, to the steel composition. The Al element has a significant effect on the density of steel. For every 1% of Al added to steel, its density decreases by about 1.3%. The Mn element also has a certain weight-reducing effect. For every 1% of Mn added to steel, its density can also be reduced, and the weight is reduced by about 0.1%.

[0003] Al is added to steel as a deoxidizer or alloying element, and its deoxidizing ability is much stronger than that of silicon and manganese. The Al content in conventional steel products is generally below 0.065%, which can refine the grains and fix the nitrogen in the steel, thereby significantly improving the impact toughness of the steel and reducing the cold brittleness tendency and aging tendency. The Al content in low-density steel is relatively high, about 3%. When the Al content in steel is high, due to the large difference in density between Al and Fe and the immiscibility of the two at low temperatures, the molten steel will be easily stratified during standing or cooling, resulting in poor uniformity of the low-density steel. Summary of the invention

[0004] The problem solved by the invention is: how to improve the uniformity of low-density steel.

[0005] In order to solve the above problems, the present invention provides a method for casting low-density steel, comprising:

[0006] Step S1, controlling the molten steel obtained by smelting to a preset temperature to obtain molten steel to be poured;

[0007] Step S2, pouring the molten steel to be poured from the storage container to the casting mold to complete the pouring and obtain a cast billet; wherein, during the pouring process, the molten steel to be poured is injected from a single side of the casting mold, and during the pouring process, the tilting angle of the storage container changes from 0 degrees in the initial state to 120 degrees in the final state, and the tilting speed during the pouring process is controlled as follows:

[0008] During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 0.95-1r / min;

[0009] During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.4-0.6r / min;

[0010] During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.2-0.4r / min;

[0011] When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.6-1.0 r / min.

[0012] Optionally, in step S2, when the tilting angle changes from 0 degrees to 60 degrees, the tilting speed is 1 r / min.

[0013] Optionally, in step S2, when the tilting angle changes from 60 degrees to 75 degrees, the tilting speed is 0.5 r / min.

[0014] Optionally, in step S2, when the tilting angle changes from 75 degrees to 95 degrees, the tilting speed is 0.3 r / min.

[0015] Optionally, in step S2, when the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.8 r / min.

[0016] Optionally, in step S1, the preset temperature is 1460-1480°C.

[0017] Optionally, in step S2, the storage container is a vacuum pouring furnace, a ladle or a tundish.

[0018] Optionally, the components of the low-density steel include, by weight percentage: C: 0.48-0.52%, Si: 0-0.05%, Mn: 4.90-5.10%, P: 0-0.020%, S: 0-0.020%, Al: 2.90-3.10%, and the balance is Fe and unavoidable impurities.

[0019] Optionally, the components of the low-density steel include, by weight percentage: C: 0.50%, Si: 0-0.01%, Mn: 5.00%, P: 0-0.010%, S: 0-0.005%, Al: 3.00%, and the balance is Fe and unavoidable impurities.

[0020] The present invention also provides a casting billet, which is made by the casting method of the low-density steel as described above.

[0021] Compared with the prior art, the present invention achieves the purpose of improving the uniformity of low-density steel by controlling the tipping speed during the pouring process. Specifically: when the tipping angle changes from 0 degrees to 60 degrees, the tipping speed is controlled to be 0.95-1r / min, ensuring that the molten steel quickly reaches the outlet position of the storage container, reducing the stagnation time of the molten steel in the storage container, which is beneficial to reducing the possibility of stratification of the molten steel, thereby facilitating improving the uniformity of the ingot, and further improving the uniformity of the low-density steel obtained by the ingot processing; when the tipping angle changes from 60 degrees to 75 degrees, the molten steel begins to flow out of the storage container, and the tipping speed is controlled to be 0.4-0.6 / min. When the tipping angle changes from 75 degrees to 95 degrees, the molten steel begins to flow out of the storage container, and the tipping speed is controlled to be 0.4-0.6 / min. , control the tipping speed to 0.2-0.4 / min, ensure that the molten steel in the pouring process flows out of the storage container at a uniform speed, and is injected from one side of the mold, so as to facilitate the smooth removal of gas during the solidification of the molten steel, thereby reducing or even avoiding the formation of pores, which is beneficial to improving the uniformity of the ingot, and then improving the uniformity of the low-density steel obtained by the ingot processing; in the process of the tipping angle changing from 95 degrees to 120 degrees, it is at the end of the pouring, and the molten steel in the storage container becomes less. The tipping speed is controlled to be 0.6-1.0r / min, and the casting is completed quickly to prevent the molten steel in the storage container from standing and causing component segregation, which is beneficial to improving the uniformity of the ingot, and then improving the uniformity of the low-density steel obtained by the ingot processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the process of pouring low-density steel in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;

[0025] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0026] It should be noted that, in the present invention, the tilting angle refers to the tilting angle of the vacuum pouring furnace, ladle or tundish when pouring molten steel into the mold during the pouring process; the tilting speed refers to the speed of changing the tilting angle of the vacuum pouring furnace, ladle or tundish when pouring molten steel during the pouring process. In the present invention, r / min represents that the rotation angle per minute is 360 degrees. "The molten steel to be poured is injected from a single side of the mold during the pouring process" means that during the casting process, the molten steel to be poured is injected into the mold from a single inlet or one side of the mold.

[0027] like Figure 1 As shown, a method for casting low-density steel provided by an embodiment of the present invention comprises:

[0028] Step S1, controlling the molten steel obtained by smelting to a preset temperature to obtain molten steel to be poured;

[0029] Step S2, pouring the molten steel to be poured from the storage container to the casting mold to complete the pouring and obtain a cast billet; wherein, during the pouring process, the molten steel to be poured is injected from a single side of the casting mold, and during the pouring process, the tilting angle of the storage container changes from 0 degrees in the initial state to 120 degrees in the final state, and the tilting speed during the pouring process is controlled as follows:

[0030] During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 0.95-1r / min;

[0031] During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.4-0.6r / min;

[0032] During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.2-0.4r / min;

[0033] When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.6-1.0 r / min.

[0034] The embodiment of the present invention achieves the purpose of improving the uniformity of low-density steel by controlling the tilting speed during the pouring process. Specifically: when the tilting angle changes from 0 degrees to 60 degrees, the tilting speed is controlled to be 0.95-1r / min, ensuring that the molten steel quickly reaches the outlet position of the storage container, reducing the calming time of the molten steel in the storage container, which is beneficial to reducing the possibility of stratification of the molten steel, thereby facilitating improving the uniformity of the ingot, and further improving the uniformity of the low-density steel obtained by the ingot processing; when the tilting angle changes from 60 degrees to 75 degrees, the molten steel begins to flow out of the storage container, and the tilting speed is controlled to be 0.4-0.6 / min. When the tilting angle changes from 75 degrees to 95 degrees, the tilting speed is controlled to be 0.95-1r / min. The tilting speed is controlled to be 0.2-0.4 / min, which ensures that the molten steel in the pouring process flows out of the storage container at a uniform speed and is injected from one side of the mold, so that the gas can be smoothly discharged during the solidification of the molten steel, thereby reducing or even avoiding the formation of pores, which is beneficial to improving the uniformity of the ingot, and further improving the uniformity of the low-density steel obtained by the ingot processing; when the tilting angle changes from 95 degrees to 120 degrees, it is at the end of the pouring, and the molten steel in the storage container becomes less. The tilting speed is controlled to be 0.6-1.0r / min, and the casting is completed quickly to prevent the molten steel in the storage container from standing and causing composition segregation, which is beneficial to improving the uniformity of the ingot, and further improving the uniformity of the low-density steel obtained by the ingot processing.

[0035] In some embodiments of the present invention, in step S1, the preset temperature is 1460-1480° C. In this embodiment, the molten steel obtained by smelting is controlled to 1460-1480° C., and the superheat is controlled to 5-25° C. to prevent excessive internal stress from causing cracks during high superheat pouring and solidification, and prevent defects such as poor fluidity and insufficient shrinkage compensation from causing pores due to poor fluidity due to too low superheat, resulting in uneven overall structure, thereby further improving the uniformity of low-density steel.

[0036] In some embodiments of the present invention, in step S2, when the tilting angle changes from 0 degrees to 60 degrees, the tilting speed is 1 r / min.

[0037] In some embodiments of the present invention, in step S2, when the tilting angle changes from 60 degrees to 75 degrees, the tilting speed is 0.5 r / min.

[0038] In some embodiments of the present invention, in step S2, when the tilting angle changes from 75 degrees to 95 degrees, the tilting speed is 0.3 r / min.

[0039] In some embodiments of the present invention, in step S2, when the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.8 r / min.

[0040] In some embodiments of the present invention, in step S2, the storage container is a vacuum pouring furnace, a ladle or a tundish.

[0041] In some embodiments of the present invention, the components of the low-density steel include, by weight percentage: C: 0.48-0.52%, Si: 0-0.05%, Mn: 4.90-5.10%, P: 0-0.020%, S: 0-0.020%, Al: 2.90-3.10%, and the balance is Fe and unavoidable impurities.

[0042] In some embodiments of the present invention, the components of the low-density steel include, by weight percentage: C: 0.50%, Si: 0-0.01%, Mn: 5.00%, P: 0-0.010%, S: 0-0.005%, Al: 3.00%, and the balance is Fe and unavoidable impurities.

[0043] The present invention also provides a casting billet, which is made by the casting method of the low-density steel as described above.

[0044] The present invention is further described below in conjunction with specific embodiments.

[0045] Example 1

[0046] A1. The molten steel obtained by smelting in a vacuum pouring furnace is controlled to a preset temperature to obtain molten steel to be poured; wherein, in terms of weight percentage, the components of the molten steel to be poured include: C: 0.50%, Si: 0.005%, Mn: 5.00%, P: 0.005%, S: 0.005%, Al: 3.00%, and the balance is Fe and unavoidable impurities; the preset temperature is 1460°C.

[0047] A2. Pour the molten steel to be poured from the storage container to the casting mold to complete the pouring and obtain a cast billet; wherein, during the pouring process, the molten steel to be poured is injected from a single side of the casting mold, and during the pouring process, the tilting angle of the storage container changes from 0 degrees in the initial state to 120 degrees in the final state, and the tilting speed during the pouring process is controlled as follows:

[0048] During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 1 r / min;

[0049] During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.6 r / min;

[0050] During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.2 r / min;

[0051] When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 1.0 r / min.

[0052] Example 2

[0053] The difference from Example 1 is that in step A1, the preset temperature is 1480°C;

[0054] In step A2, the tipping speed during the tipping process is controlled as follows:

[0055] During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 1 r / min;

[0056] During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.5 r / min;

[0057] During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.3 r / min;

[0058] When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.9 r / min.

[0059] Example 3

[0060] The difference from Example 1 is that in step A2, the tipping speed during the tipping process is controlled as follows:

[0061] During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 0.95 r / min;

[0062] During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.4r / min;

[0063] During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.4 r / min;

[0064] When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.6 r / min.

[0065] Comparative Example 1

[0066] The difference from Example 1 is that in step A2, the tipping speed during the tipping process is controlled as follows:

[0067] During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 1 r / min;

[0068] During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.3 r / min;

[0069] During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.3 r / min;

[0070] When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.4 r / min.

[0071] Comparative Example 2

[0072] The difference from Example 1 is that in step A2, the tipping speed during the tipping process is controlled as follows:

[0073] During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 1 r / min;

[0074] During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.2 r / min;

[0075] During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.1 r / min;

[0076] When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.4 r / min.

[0077] Experimental example

[0078] The components of different parts of the ingots prepared in Examples 1-3 and Comparative Examples 1-2 were analyzed, and the results are shown in Table 1. It can be seen from Table 1 that, compared with Comparative Examples 1-2, the components of various parts of the ingots prepared in Example 1 are more uniform, among which the fluctuation deviations of the Mn content and the Al content are smaller, both within 0.02%.

[0079] Table 1

[0080]

[0081]

[0082] It should be noted that “upper left” in Table 1 represents the upper left part of the ingot, “lower left” in Table 1 represents the lower left part of the ingot, “upper right” in Table 1 represents the upper right part of the ingot, and “lower right” in Table 1 represents the lower right part of the ingot.

[0083] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for casting low-density steel, characterized in that: include: Step S1, controlling the molten steel obtained by smelting to a preset temperature to obtain molten steel to be poured; Step S2, pouring the molten steel to be poured from the storage container to the casting mold to complete the pouring, and obtaining a cast billet; wherein, during the pouring process, the molten steel to be poured is injected from a single side of the casting mold, and the tilting angle of the storage container changes from 0 degrees in the initial state to 120 degrees in the final state, and the tilting speed during the pouring process is controlled as follows: During the process of the tilting angle changing from 0 degrees to 60 degrees, the tilting speed is 0.95-1r / min; During the process of the tilting angle changing from 60 degrees to 75 degrees, the tilting speed is 0.4-0.6r / min; During the process of the tilting angle changing from 75 degrees to 95 degrees, the tilting speed is 0.2-0.4r / min; When the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.6-1.0 r / min.

2. The method for casting low-density steel according to claim 1, characterized in that: In the step S2, when the tilting angle changes from 0 degrees to 60 degrees, the tilting speed is 1 r / min.

3. The method for casting low-density steel according to claim 1, characterized in that: In step S2, when the tilting angle changes from 60 degrees to 75 degrees, the tilting speed is 0.5 r / min.

4. The method for casting low-density steel according to claim 1, characterized in that: In step S2, when the tilting angle changes from 75 degrees to 95 degrees, the tilting speed is 0.3 r / min.

5. The method for casting low-density steel according to claim 1, characterized in that: In step S2, when the tilting angle changes from 95 degrees to 120 degrees, the tilting speed is 0.8 r / min.

6. The method for casting low-density steel according to claim 1, characterized in that: In the step S1, the preset temperature is 1460-1480°C.

7. The method for casting low-density steel according to claim 1, characterized in that: In step S2, the storage container is a vacuum pouring furnace, a ladle or a tundish.

8. The method for casting low-density steel according to claim 1, characterized in that: Measured by weight percentage, the components of the low-density steel include: C: 0.48-0.52%, Si: 0-0.05%, Mn: 4.90-5.10%, P: 0-0.020%, S: 0-0.020%, Al: 2.90-3.10%, and the balance is Fe and inevitable impurities.

9. The method for casting low-density steel according to claim 8, characterized in that: Measured by weight percentage, the components of the low-density steel include: C: 0.50%, Si: 0-0.01%, Mn: 5.00%, P: 0-0.010%, S: 0-0.005%, Al: 3.00%, and the balance is Fe and inevitable impurities.

10. A casting billet, characterized in that: The low-density steel is made by the casting method of any one of claims 1 to 9.

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