Steel plate, manufacturing method thereof and refrigerator

Abstract

The invention discloses a steel plate, a manufacturing method thereof and a refrigerator, and belongs to the technical field of steel plates for refrigerators. The steel plate is used as a bottom plate of the refrigerator compressor and comprises C, Si, Mn, P, S, Alt, Nb, Ti and Fe. In parts by mass, the use amount of C is selected from any one value of 0.04-0.06%, the use amount of Si is smaller than or equal to 0.04%, the use amount of Mn is selected from any one value of 0.25-0.40%, the use amount of P is smaller than or equal to 0.015%, the use amount of S is smaller than or equal to 0.015%, the use amount of Alt is selected from any one value of 0.02-0.05%, the use amount of Nb is selected from any one value of 0.055-0.065%, and the use amount of Ti is selected from any one value of 0.01-0.03%. The steel plate is applied to the technical field of refrigerator compressor bottom plate plates, the problem that when an existing DX51D + Z hot-dip galvanized steel plate with the thickness of 1.0 mm is used for a refrigerator compressor bottom plate, impact deformation exists is solved, the requirement of the refrigerator compressor bottom plate for metal plate thickness reduction can be met, and meanwhile the steel plate has the advantages of being high in strength, high in extensibility and resistant to deformation.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel plates for refrigerators, and particularly relates to a steel plate, a manufacturing method thereof, and a refrigerator. Background Art

[0002] The refrigerator compressor bottom plate is located at the bottom of the refrigerator and mainly bears the compressor, condenser, and part of the circuit. Since the refrigerator compressor bottom plate bears the relatively heavy refrigeration core component, the compressor, if it is deformed after being impacted by an external force, it is very easy to damage the compressor and the pipeline connecting the compressor. Therefore, the material used for the refrigerator compressor bottom plate not only needs to meet the strength requirements but also needs to meet the anti-deformation requirements.

[0003] Currently, the material selected for the refrigerator compressor bottom plate is mainly DX51D+Z (or DC51D+Z, which will be uniformly replaced by DX51D+Z hereinafter) hot-dip galvanized steel plate. This type of hot-dip galvanized steel plate is widely used in the compressor bottom plate, rear plate, structural parts of the refrigerator, and the color steel plate substrate for the front panel and side panel. Different parts use different thicknesses due to different forces. DX51D+Z belongs to low-carbon aluminum-killed steel and is widely used in the parts of household electrical appliances. This type of material has a certain structural strength, is easy to bend and form, and the surface hot-dip galvanized layer also ensures the corrosion resistance in high-temperature and high-humidity environments.

[0004] However, since there are no clear range requirements for the yield strength of DX51D+Z in the national standard and the enterprise standard of steel enterprises, the yield strength of general DX51D+Z hot-dip galvanized steel plates fluctuates within the range of 180 - 300 MPa. When approaching the lower limit, the yield strength is insufficient, resulting in insufficient resistance to deformation of the compressor bottom plate. Although it can be improved by methods such as welding reinforcing ribs or increasing the thickness, it will cause cost losses to both refrigerator factories and steel enterprises. Summary of the Invention

[0005] Aiming at the deficiencies existing in the prior art, the technical problem to be solved by the present invention is to overcome the problem of impact deformation when the existing DX51D+Z hot-dip galvanized steel plate with a thickness of 1.0 mm is used for the refrigerator compressor bottom plate, and to propose a steel plate, a manufacturing method thereof, and a refrigerator that can meet the requirements of the refrigerator compressor bottom plate for reducing the sheet metal thickness, and at the same time have the characteristics of high strength, high extensibility, and anti-deformation.

[0006] To solve the above technical problem, the technical solution adopted by the present invention is as follows:

[0007] On the one hand, the present invention provides a steel plate used as the bottom plate material of a refrigerator compressor. The constituent elements include: C, Si, Mn, P, S, Alt, Nb, Ti, Fe; by mass fraction, the dosage of C is selected from any value in the range of 0.04 - 0.06%, the dosage of Si ≤ 0.04%, the dosage of Mn is selected from any value in the range of 0.25 - 0.40%, the dosage of P ≤ 0.015%, the dosage of S ≤ 0.015%, the dosage of Alt is selected from any value in the range of 0.02 - 0.05%, the dosage of Nb is selected from any value in the range of 0.055 - 0.065%, and the dosage of Ti is selected from any value in the range of 0.01 - 0.03%.

[0008] Preferably, the thickness of the steel plate is 0.8 mm, the dosage of C is 0.05%, the dosage of Mn is 0.30%, the dosage of Alt is 0.04%, the dosage of Nb is 0.060%, and the dosage of Ti is 0.02%.

[0009] Preferably, the yield strength of the steel plate is any value in the range of 280 - 340 MPa, the tensile strength is any value in the range of 340 - 440 MPa, and the elongation after fracture ≥ 30%.

[0010] On the other hand, the present invention provides a manufacturing method of the steel plate according to any of the above technical solutions, including a hot rolling step, a cold rolling step, and a continuous annealing and hot-dip galvanizing production line step for cold-rolled strip steel.

[0011] Preferably, in the hot rolling step, the heating temperature of the heating furnace is any value in the range of 1230 - 1250 °C.

[0012] Preferably, in the hot rolling step, the rough rolling exit temperature is any value in the range of 1030 - 1100 °C, and the finish rolling temperature is any value in the range of 870 - 900 °C.

[0013] Preferably, in the hot rolling step, the coiling temperature is any value in the range of 560 - 600 °C.

[0014] Preferably, in the cold rolling step, the hot-rolled strip steel is cold-rolled with a reduction rate of 70 - 80%.

[0015] Preferably, in the continuous annealing and hot-dip galvanizing production line step for cold-rolled strip steel, annealing is carried out at 780 - 820 °C, held for 55 - 65 s, and continuous hot-dip galvanizing is carried out during the cooling process from this temperature.

[0016] The present invention also provides a refrigerator, the bottom plate material of the refrigerator compressor of which uses the steel plate according to any of the above technical solutions.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention provides a steel plate with a yield strength ≥ 300 MPa, a tensile strength ≥ 350 MPa, an elongation after fracture ≥ 30%, and a thickness of 0.8 mm. It has the characteristics of high strength and high ductility. When this steel plate is used for the bottom plate of a refrigerator compressor, it can meet the requirement of reducing the sheet metal thickness of the bottom plate of the refrigerator compressor, which is beneficial to cost reduction. Description of the Drawings

[0019] Figure 1 It is a photo of the microscopic metallographic structure of the steel coil provided in Embodiment 1 of the present invention. Detailed Embodiments

[0020] Hereinafter, the technical solutions in the specific embodiments of the present invention will be described in detail and completely. Obviously, the described embodiments are only partial specific embodiments of the overall technical solution of the present invention, rather than all embodiments. Based on the overall concept of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of the present invention.

[0021] On the one hand, the present invention provides a steel plate used as the sheet material for the bottom plate of a refrigerator compressor. The constituent elements include: C, Si, Mn, P, S, Alt, Nb, Ti, Fe. By mass fraction, the amount of C used is selected from any value in the range of 0.04 - 0.06%, the amount of Si used ≤ 0.04%, the amount of Mn used is selected from any value in the range of 0.25 - 0.40%, the amount of P used ≤ 0.015%, the amount of S used ≤ 0.015%, the amount of Alt used is selected from any value in the range of 0.02 - 0.05%, the amount of Nb used is selected from any value in the range of 0.055 - 0.065%, and the amount of Ti used is selected from any value in the range of 0.01 - 0.03%. This steel plate is a high strength low alloy steel. The above technical solution limits the amounts of C, Si, Mn, P, S, Alt, Nb, and Ti, and the balance is Fe and impurities. It can be understood that the amount of C can also be 0.045%, 0.050%, 0.055% and any point value within its range, the amount of Mn can also be 0.30%, 0.35% and any point value within its range, the amount of Alt can also be 0.025%, 0.030%, 0.035%, 0.040%, 0.045% and any point value within its range, the amount of Nb can also be 0.060% and any point value within its range, and the amount of Ti can also be 0.015%, 0.020%, 0.025% and any point value within its range.

[0022] The impurities in the above-mentioned steel plate are trace impurities that are inevitable in the process of steel production. Through the optimization of the steel plate composition, the present invention retains the technical requirements of ductility while enhancing the yield strength. In the above-mentioned steel plate of the present invention, the C element is the most basic and main solid-solution strengthening element in steel and is the main element for distinguishing steel grade series. It can endow the material with high strength. However, an increase in the C content will reduce the drawability of the material and directly affect the stamping and bending properties. Therefore, the C content cannot be too high. Considering the design goal of the mechanical properties of the material, the C content is controlled at 0.04-0.06%; Si is a solid-solution strengthening element, but an increase in the Si content will form an oxide layer on the surface of the steel plate, affecting the galvanizing effect. Therefore, the Si content ≤ 0.04%; Mn is the main solid-solution strengthening element, which has an obvious effect on strength improvement. However, too high an Mn element will also affect the galvanizing effect. Therefore, the Mn content is controlled at 0.25-0.40%; P is a strong solid-solution strengthening element, but when the P content > 0.02%, it is easy to cause grain boundary segregation of the slab and result in intergranular fracture. Therefore, the P content ≤ 0.015%; S precipitates in the form of manganese sulfide inclusions in steel, having an adverse effect on the plasticity of steel. Therefore, the S content ≤ 0.015%; the main function of Al is to deoxidize during the refining process and play a calming effect. Therefore, it should not be too low, and the Alt content is controlled at 0.02-0.05%; Nb is a microalloying element, which can form fine and dispersed second-phase particles, prevent the growth of austenite grains, and finally make the ferrite grain size smaller, achieving the effect of refining the grain structure and effectively hindering dislocation movement to cause strengthening; the Ti element can form TiC to produce a precipitation strengthening effect. However, the precipitation of TiC is very sensitive to temperature and cooling rate. During the hot rolling process, the temperature of the slab fluctuates greatly in all directions, easily causing fluctuations in mechanical properties at different positions. Therefore, the Ti content should not be too high and should be < 0.04%.

[0023] In a preferred embodiment, the thickness of the steel plate is 0.8 mm, the dosage of C is 0.05%, the dosage of Mn is 0.30%, the dosage of Alt is 0.04%, the dosage of Nb is 0.060%, and the dosage of Ti is 0.02%. This technical solution further defines the composition of the steel plate. The yield strength of this steel plate ≥ 300 MPa, the tensile strength ≥ 350 MPa, the elongation after fracture ≥ 30%, and the thickness is only 0.8 mm. It has the characteristics of high strength and high ductility. Using this steel plate for the bottom plate of a refrigerator compressor can also meet the requirement of the bottom plate of the refrigerator compressor for reducing the sheet metal thickness, which is beneficial to cost reduction.

[0024] In a preferred embodiment, the yield strength of the steel plate is any value in the range of 280 - 340 MPa, the tensile strength is any value in the range of 340 - 440 MPa, and the elongation after fracture is ≥ 30%. It can be understood that the yield strength of the steel plate can also be 300 MPa, 320 MPa, and any point value within this range, and the tensile strength can also be 360 MPa, 380 MPa, 400 MPa, 420 MPa, and any point value within this range.

[0025] On the other hand, the present invention provides a manufacturing method of the steel plate according to any of the above technical solutions, including a hot rolling step, a cold rolling step, and a continuous annealing and hot-dip galvanizing production line step for cold-rolled strip steel.

[0026] In a preferred embodiment, in the hot rolling step, the heating temperature of the heating furnace is any value in the range of 1230 - 1250 °C. This technical solution specifically defines the heating temperature of the heating furnace in the hot rolling step, which is beneficial to the full solution of Nb and Ti compounds in the slab. It can be understood that the heating temperature of the heating furnace can also be 1240 °C.

[0027] In a preferred embodiment, in the hot rolling step, the rough rolling exit temperature is any value in the range of 1030 - 1100 °C, and the finish rolling temperature is any value in the range of 870 - 900 °C. It should be noted that to avoid fluctuations in the rolling force caused by the finish rolling entering the two-phase region for rolling, the finish rolling temperature should be above the A3 temperature and greater than 870 °C. This technical solution defines the finish rolling temperature as 870 - 900 °C. It can be understood that the rough rolling exit temperature can also be 1040 °C, 1050 °C, 1060 °C, 1070 °C, 1080 °C, 1090 °C, and any point value within this range, and the finish rolling temperature can also be 880 °C, 890 °C, and any point value within this range.

[0028] In a preferred embodiment, in the hot rolling step, the coiling temperature is any value in the range of 560 - 600 °C. A too high coiling temperature will make the grains of the hot rolled coil coarse and cause a decrease in strength after cold rolling annealing. A too low coiling temperature will lead to insufficient precipitation of the second-phase particles. Therefore, this technical solution defines the coiling temperature as 560 - 600 °C. It can be understood that the coiling temperature in the hot rolling step can also be 570 °C, 580 °C, 590 °C, and any point value within this range.

[0029] Furthermore, in the hot rolling step, the heating furnace temperature is 1240 °C, the rough rolling exit temperature is 1060 °C, the finish rolling temperature is 880 °C, and the coiling temperature is 580 °C.

[0030] In a preferred embodiment, in the cold rolling step, the hot rolled strip is cold rolled at a reduction rate of 70%-80%. The cold rolling thickness is the thickness of the final product, and the cold rolling deformation provides a driving force for the subsequent recrystallization annealing. According to the usage requirements of the refrigerator compressor bottom plate, the cold rolling reduction rate of the present invention is controlled to be 70%-80%, and the thickness is 0.8 mm. It can be understood that the cold rolling reduction rate can also be 72%, 75%, 77% and any point value within this range. Preferably, the hot rolled strip is cold rolled at a reduction rate of 75%.

[0031] In a preferred embodiment, in the cold rolled strip continuous annealing and hot dip galvanizing production line step, annealing is carried out at 780-820°C, held for 55-65 s, and continuous hot dip galvanizing is carried out during the cooling process from the said temperature. In the cold rolled strip continuous annealing and hot dip galvanizing production line step, the recrystallization annealing temperature is the most core process factor for controlling the performance. To avoid the situation of high yield strength and low elongation after fracture caused by insufficient recrystallization annealing, the annealing temperature is controlled to be 780-820°C, and the holding time is 55-65 s. It can be understood that the annealing temperature can also be 790°C, 800°C, 810°C and any point value within this range, and the holding time can also be 57 s, 59 s, 61 s, 63 s and any point value within this range. Skin pass rolling can improve the plate shape, remove the yield plateau, and has a certain promoting effect on the yield strength. The skin pass elongation is controlled to be 1.2%-1.5%. It can be understood that the skin pass elongation can also be 1.3%, 1.4% and any point value within this range.

[0032] The present invention also provides a refrigerator, and the refrigerator compressor bottom plate is made of the steel plate described in any of the above technical solutions. By optimizing the composition design, adjusting the contents of C, Mn, Alt, and Ti, and combining with the optimization of hot rolling, cold rolling, and continuous annealing and hot dip galvanizing processes, the produced steel plate has the characteristics of high strength and high elongation. Using this steel plate for the refrigerator compressor bottom plate can meet the further requirements of such products for strength and sheet metal thinning, which is beneficial to cost reduction. Among them, the yield strength of the steel plate is ≥300 MPa, the tensile strength is ≥350 MPa, the elongation after fracture is ≥30%, and the thickness is 0.8 mm. The steel plate used for this refrigerator meets the requirements of both high strength and sheet metal thinning of the compressor bottom plate.

[0033] In order to introduce the steel plate, its manufacturing method and refrigerator provided by the embodiments of the present invention more clearly and in detail, the following will be described in combination with specific embodiments.

[0034] Example 1

[0035] This example provides a steel plate for a refrigerator compressor bottom plate.

[0036] (1) Formula

[0037] The steel plate includes C, Si, Mn, P, S, Alt, Nb, Ti. Except for the above elements, the balance is Fe and impurities.

[0038] By mass fraction, the mass fraction of C is 0.04%, the mass fraction of Si ≤ 0.04%, the mass fraction of Mn is 0.25%, the mass fraction of P ≤ 0.015%, the mass fraction of S ≤ 0.015%, the mass fraction of Alt is 0.02%, the mass fraction of Nb is 0.055%, and the mass fraction of Ti is 0.01%.

[0039] (2) Manufacturing method

[0040] The above raw materials are processed by hot rolling, cold rolling, and the process of a continuous annealing hot-dip galvanizing production line for cold-rolled strip steel. Specifically:

[0041] The heating temperature of the heating furnace is 1230 °C, the outlet temperature of rough rolling is 1050 °C, the final rolling temperature of finish rolling is 870 °C, the coiling temperature is 560 °C, and the cold rolling reduction rate is 70%.

[0042] Example 2

[0043] This example provides a steel plate for the bottom plate of a refrigerator compressor.

[0044] (1) Formula

[0045] The steel plate includes C, Si, Mn, P, S, Alt, Nb, Ti. Except for the above elements, the balance is Fe and impurities.

[0046] By mass fraction, the mass fraction of C is 0.05%, the mass fraction of Si ≤ 0.04%, the mass fraction of Mn is 0.30%, the mass fraction of P ≤ 0.015%, the mass fraction of S ≤ 0.015%, the mass fraction of Alt is 0.04%, the mass fraction of Nb is 0.059%, and the mass fraction of Ti is 0.02%.

[0047] (2) Manufacturing method

[0048] The above raw materials are processed by hot rolling, cold rolling, and the process of a continuous annealing hot-dip galvanizing production line for cold-rolled strip steel. Specifically:

[0049] The heating temperature of the heating furnace is 1240 °C, the outlet temperature of rough rolling is 1060 °C, the final rolling temperature of finish rolling is 880 °C, the coiling temperature is 580 °C, and the cold rolling reduction rate is 75%.

[0050] Example 3

[0051] This example provides a steel plate for the bottom plate of a refrigerator compressor.

[0052] (1) Formula

[0053] The steel plate includes C, Si, Mn, P, S, Alt, Nb, Ti. Except for the above elements, the balance is Fe and impurities.

[0054] By mass fraction, the mass fraction of C is 0.06%, the mass fraction of Si ≤ 0.04%, the mass fraction of Mn is 0.35%, the mass fraction of P ≤ 0.015%, the mass fraction of S ≤ 0.015%, the mass fraction of Alt is 0.04%, the mass fraction of Nb is 0.066%, and the mass fraction of Ti is 0.03%.

[0055] (2) Manufacturing method

[0056] The above raw materials are processed by hot rolling, cold rolling, and the process of a continuous annealing hot-dip galvanizing production line for cold-rolled strip steel. Specifically:

[0057] The heating temperature of the heating furnace is 1250 °C, the outlet temperature of rough rolling is 1060 °C, the final rolling temperature of finish rolling is 900 °C, the coiling temperature is 600 °C, and the cold rolling reduction rate is 80%.

[0058] Comparative Example 1

[0059] This example provides a steel plate for the bottom plate of a refrigerator compressor.

[0060] (1) Formulation

[0061] The steel plate includes C, Si, Mn, P, S, Alt, Ti. Except for the above elements, the balance is Fe and impurities.

[0062] By mass fraction, the mass fraction of C is 0.04%, the mass fraction of Si ≤ 0.04%, the mass fraction of Mn is 0.24%, the mass fraction of P ≤ 0.015%, the mass fraction of S ≤ 0.015%, the mass fraction of Alt is 0.032%, and the mass fraction of Ti is 0.0003%.

[0063] (2) Manufacturing method

[0064] The above raw materials are processed by hot rolling, cold rolling, and the process of a continuous annealing hot-dip galvanizing production line for cold-rolled strip steel. Specifically:

[0065] The heating temperature of the heating furnace is 1210 °C, the outlet temperature of rough rolling is 1060 °C, the final rolling temperature of finish rolling is 880 °C, and the coiling temperature is 700 °C.

[0066] Cold rolling process parameters: The cold rolling reduction rate of hot-rolled strip steel is 77%.

[0067] Comparative Example 2

[0068] This example provides a hot-dip aluminum-zinc steel plate for the bottom plate of a refrigerator compressor.

[0069] (1) Formula

[0070] The steel plate comprises C, Si, Mn, P, S, Alt, Ti. Except for the above elements, the balance is Fe and impurities.

[0071] By mass fraction, the mass fraction of C is 0.0021%, the mass fraction of Si is 0.0172%, the mass fraction of Mn is 0.41%, the mass fraction of P is 0.0583%, the mass fraction of S is 0.011%, the mass fraction of Alt is 0.021%, and the mass fraction of Ti is 0.0054%.

[0072] (2) Manufacturing method

[0073] The above raw materials are processed by hot rolling, cold rolling, and the process of a continuous annealing hot-dip galvanizing production line for cold-rolled strip steel. Specifically:

[0074] The heating temperature of the heating furnace is 1219 °C, the outlet temperature of rough rolling is 1070 °C, the final rolling temperature of finish rolling is 922 °C, and the coiling temperature is 683 °C.

[0075] Cold rolling process parameters: The cold rolling reduction rate of hot-rolled strip steel is 90%.

[0076] Hot-dip galvanizing process parameters: The annealing temperature is 780 °C, and the skin pass elongation is 0.61%.

[0077] Performance results: Yield strength 228 MPa, tensile strength 388 MPa, elongation after fracture 28%.

[0078] Comparative Example 3

[0079] This example provides a hot-dip galvanized steel plate.

[0080] (1) Formula

[0081] The steel plate comprises C, Si, Mn, P, S, Alt, Nb, Ti. Except for the above elements, the balance is Fe and impurities.

[0082] By mass fraction, the mass fraction of C is 0.04%, the mass fraction of Si is 0.0226%, the mass fraction of Mn is 0.2388%, the mass fraction of P is 0.0095%, the mass fraction of S is 0.0053%, the mass fraction of Alt is 0.0361%, the mass fraction of Nb is 0.055%, and the mass fraction of Ti is 0.003%.

[0083] (2) Manufacturing method

[0084] The above raw materials are processed by hot rolling, cold rolling, and the process of a continuous annealing hot-dip galvanizing production line for cold-rolled strip steel. Specifically:

[0085] The heating temperature of the heating furnace is 1236 °C, the rough rolling exit temperature is 1070 °C, the finish rolling temperature is 883 °C, and the coiling temperature is 705 °C.

[0086] Cold rolling process parameters: The cold rolling reduction rate of the hot rolled strip is 80%, and the cold rolling exit thickness is 0.8 mm.

[0087] Hot dip galvanizing process parameters: The annealing temperature is 780 °C, and the skin pass elongation is 1.30%.

[0088] Performance results: The yield strength is 228 MPa, the tensile strength is 359 MPa, and the elongation after fracture is 37%.

[0089] Performance test

[0090] The cold rolled strip obtained from the above Examples 1-3 and Comparative Examples 1-3 was subjected to a continuous annealing hot dip galvanizing line. The annealing temperature was 780-820 °C, the holding time was 55-65 s, and continuous hot dip galvanizing was carried out during the cooling from this temperature. Among them, the microscopic metallographic structure photograph of the steel coil obtained in Example 1 is as Figure 1 shown. The properties of the hot dip galvanized steel sheets obtained in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.

[0091] Table 1 Properties of the hot dip galvanized steel sheets obtained in Examples 1-3 and Comparative Examples 1-2

[0092]

[0093] It can be found from the results in Table 1 that the mechanical properties of the hot dip galvanized products manufactured according to the method (including chemical composition and process) described in the present invention. It can be seen that by using the alloy addition method mainly based on C, Mn, Al, and Nb, combined with an appropriate production process system, hot dip galvanized steel sheets with thickness and mechanical properties meeting the requirements can be produced, with a yield strength ≥ 300 MPa, a tensile strength ≥ 350 MPa, and an elongation after fracture ≥ 30%.

Claims

1. A steel plate, characterized in that: Used as refrigerator compressor bottom plate, the constituent elements include: C, Si, Mn, P, S, Alt, Nb, Ti, Fe; In terms of mass fraction, the amount of C is selected from any value in the range of 0.04-0.06%, the amount of Si is ≤0.04%, the amount of Mn is selected from any value in the range of 0.25-0.40%, the amount of P is ≤0.015%, the amount of S is ≤0.015%, the amount of Alt is selected from any value in the range of 0.02-0.05%, the amount of Nb is selected from any value in the range of 0.055-0.065%, and the amount of Ti is selected from any value in the range of 0.01-0.03%.

2. The steel plate according to claim 1, characterized in that: The thickness of the steel plate is 0.8 mm, the amount of C is 0.05%, the amount of Mn is 0.30%, the amount of Alt is 0.04%, the amount of Nb is 0.060%, and the amount of Ti is 0.02%.

3. The steel plate according to claim 1, characterized in that: The yield strength of the steel plate is any value between 280 and 340 MPa, the tensile strength is any value between 340 and 440 MPa, and the elongation after fracture is ≥30%.

4. The method for manufacturing a steel plate according to any one of claims 1 to 3, characterized in that: It includes hot rolling step, cold rolling step, and cold rolled strip continuous annealing hot dip galvanizing production line step.

5. The method for manufacturing a steel plate according to claim 4, characterized in that: In the hot rolling step, the heating temperature of the heating furnace is any value between 1230-1250°C.

6. The method for manufacturing a steel plate according to claim 4, characterized in that: In the hot rolling step, the rough rolling outlet temperature is any value in the range of 1030-1100°C, and the finishing rolling temperature is any value in the range of 870-900°C.

7. The method for manufacturing a steel plate according to claim 4, characterized in that: In the hot rolling step, the coiling temperature is any value in the range of 560-600°C.

8. The method for manufacturing a steel plate according to claim 4, characterized in that: In the cold rolling step, the hot rolled strip is cold rolled at a reduction rate of 70-80%.

9. The method for manufacturing a steel plate according to claim 4, characterized in that: In the step of the cold-rolled strip continuous annealing and hot-dip galvanizing production line, annealing is performed at 780-820° C., the temperature is kept for 55-65 seconds, and continuous hot-dip galvanizing is performed during cooling from the temperature.

10. A refrigerator, characterized in that: The refrigerator compressor bottom plate material is made of the steel plate described in any one of claims 1-3.

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