A method for evaluating the ultimate capacity of flying shear shearing ultra-high strength steel

Abstract

The present invention provides an evaluation method for the ultimate capacity of flying shears to shear ultra-high-strength steel, which relates to the technical field of strip shearing. The method fully considers the related defects such as poor strip shearing quality and poor shearing accuracy caused by insufficient shearing power supply when the swing-type flying shear shears shear ultra-high-strength steel. By analyzing the shearing structure characteristics of the swing-type flying shear, the influence of the thickness and width changes of the strip on the shearing capacity is studied, and the corresponding shearing force, shearing work and shearing power calculation model is established. By comparing the calculated shearing power with the shearing power allowed under safe conditions when the flying shear shears shear the strip, the ultimate capacity of shearing ultra-high-strength steel under specific equipment conditions is obtained, ensuring the smooth progress of strip production, improving the actual production efficiency and quality, and bringing economic benefits to the unit. The present invention determines the shearing capacity of the swing-type flying shear, and realizes the evaluation of the transverse ultimate shearing capacity of the strip under different incoming material specifications.

Description

Technical Field

[0001] The invention belongs to the technical field of strip steel shearing, and in particular relates to a method for evaluating the ultimate capacity of flying shear shearing ultra-high strength steel. Background Art

[0002] In recent years, with the continuous development of steel rolling equipment towards automation and intelligence, steel rolling technology has been qualitatively improved. As an indispensable link in the production process of strip steel, the working efficiency and shearing quality of the swing shear directly affect the production efficiency of the entire production unit, the quality of the strip section and the product accuracy. The flying shear is generally arranged on the continuous cold rolling unit line. In the production process of strip steel, it is mainly used to shear the head and tail of the strip steel or to shear the strip steel into the required specifications for production, in preparation for the next processing step. It can also be installed separately in the strip steel cross-cutting unit, continuous galvanizing or electro-tinning unit to shear the produced strip steel into a fixed length of blank. The swing shear generates power through a high-power DC servo motor to perform transverse shearing of the strip steel. Its structure mainly includes a transmission box, a synchronous mechanism, a shearing swing mechanism and other auxiliary facilities. When the flying shear is working, the motion trajectory of the shear blade on the equipment is required to be a closed curve to ensure that the shearing will not affect the movement of the strip steel. Different incoming material specifications have different requirements on the shearing capacity of the equipment. With the increase of strip thickness and width, under equal conditions, the shear deformation of the strip increases, the shear resistance that needs to be overcome increases, and the shearing force required to shear the strip increases accordingly. As the strip thickness increases, the shearing force and shearing power required for the flying shear to shear the strip horizontally increase accordingly. When the shearing power exceeds the shearing power allowed by the flying shear equipment under safe conditions, the insufficient shearing power supply will lead to related defects such as poor strip shearing quality and poor shearing accuracy. In this way, how to ensure that the strip can be smoothly sheared during the shearing process has become the focus of on-site research.

[0003] At present, most of the research at home and abroad is to study the influence of different shear gaps on the shearing quality of strip steel, analyze the relationship between the change of shear gap and shear force, and select different shear gap values ​​to minimize the level of poor shearing quality defects during the shearing process of the flying shear under the conditions of product specifications, steel grades and rolling procedures, thereby improving the shearing accuracy of the flying shear during the shearing process and obtaining good product quality. However, there is no evaluation method for the limit of the shearing of the flying shear for different incoming material specifications. Summary of the invention

[0004] In view of this, the present invention provides an evaluation method for the ultimate capacity of flying shears to shear ultra-high-strength steel, which fully takes into account the related defects of the swing-type flying shear such as poor strip shearing quality and poor shearing accuracy due to insufficient shearing power supply when shearing ultra-high-strength steel, by analyzing the shearing structure characteristics of the swing-type flying shear, studying the influence of changes in strip thickness and width on the shearing capacity, and establishing corresponding shear force, shearing work and shearing power calculation models, and by comparing the calculated shearing power with the shearing power allowed under safe conditions when the flying shear shears shear the strip, the ultimate capacity of shearing ultra-high-strength steel under specific equipment conditions is obtained, thereby ensuring the smooth progress of strip production, improving the actual production efficiency and quality, and bringing economic benefits to the unit.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for evaluating the ultimate capacity of flying shear shearing ultra-high strength steel, comprising:

[0007] Step A, obtain the shearing equipment parameters, strip steel specifications and performance parameters during the shearing process of the swing-type flying shear: the fixed length l of the flying shear during shearing, the running speed v of the strip steel during the flying shear operation, the inclination angle α of the shear blade during the flying shear operation, and the rated power N of the flying shear. e , power margin η when the flying shear is working, relative value Y of the gap between the blades when the flying shear is working, relative distance X of the pressure plate when the flying shear is working, strength σ of the sheared strip b , elongation of the sheared strip δ;

[0008] Step B, initializing the strip thickness adjustment coefficient λ, the strip width adjustment coefficient β, the strip thickness calculation times i and the strip width calculation times j; determining the strip thickness optimization step length Δh when shearing ultra-high strength steel, and the strip width optimization step length Δb when shearing ultra-high strength steel;

[0009] Step C: Calculate the pure shear force P of the swing shear when shearing ultra-high strength steel according to the calculation formula of the pure shear force of the oblique blade shear 1 ;

[0010] Step D: According to the shearing theory of the oblique blade shearing machine, a shearing force calculation model of the oblique blade shearing machine is established to calculate the total shearing force P when the flying shear shears shear the ultra-high strength steel:

[0011]

[0012] Among them, P 2 is the bending force of the sheared part of the rolled piece when the flying shear cuts the strip, P 3 It is the bending force of the steel plate in the shearing area when the flying shear shears the strip; is the calculation coefficient, which is related to the strip width b, thickness h, strip elongation at break δ and blade inclination angle α;

[0013] Step E: Calculate the shearing work A consumed by the total shearing force when the ultra-high-strength steel is sheared transversely according to the total shearing force P when the flying shear shears shear the ultra-high-strength steel. The calculation formula is: Among them, b j b is the strip width when the flying shear cuts ultra-high strength steel, j =b min +βΔb,b min is the minimum strip width when the flying shear cuts ultra-high strength steel, β is the strip width adjustment coefficient, and Δb is the optimization step length of ultra-high strength steel strip width;

[0014] Step F: According to the shearing work A consumed by the flying shear when transversely shearing the ultra-high-strength steel, the shearing power N of the swing flying shear when working continuously is calculated by measuring and collecting the running speed v and the fixed length l of the strip when the flying shear is working. The calculation formula is: Among them, t is the time interval between two shearings when the flying shear cuts the strip steel, ξ is the friction with air and other additional energy consumption coefficients in the shearing machine mechanism;

[0015] Step G: According to the rated power N of the shearing machine e and the power margin η when the flying shear is working, the shearing power N allowed under safe conditions when the flying shear is shearing the strip is calculated 1 =N e (1-η), and judge that N≤N 1 Is it true? If so, it means that the shearing limit of the shearing machine has not been reached. Otherwise, it means that the shearing limit has been reached.

[0016] Furthermore, the calculation formula of the pure shear force of the oblique blade shearing machine is:

[0017] Among them, h i =h max -λΔh;h max h is the maximum thickness of the strip when the flying shear cuts ultra-high strength steel; i is the thickness of the strip when the flying shear cuts the ultra-high strength steel, i = 1, 2…n, n is the final cycle number of the strip width, k is the blade passivation coefficient when the flying shear cuts the strip, K 1 , K 2 It is the conversion factor for calculating the shearing work required to shear a unit length of strip.

[0018] Furthermore, when the flying shear has reached the shearing limit, the strip width b(i) = b j-1 , b(i) is the strip thickness h i The maximum width that the shear can cut is saved.

[0019] Furthermore, when the shearing machine has reached the shearing limit, it also includes:

[0020] Determine the thickness h of the strip cut by the flying shear min ≤h i ≤h max Whether the condition is met;

[0021] If it is established, let i=i+1,λ=λ+1, and return to calculate the pure shear force P when the swing shear shears the ultra-high strength steel. 1 steps, where h i is the strip thickness when the flying shear cuts ultra-high strength steel, i = 1, 2…n, n is the strip width and the final number of cycles, h min h is the minimum thickness of the strip when the flying shear cuts ultra-high strength steel. max It is the maximum thickness of the strip when the flying shear cuts ultra-high strength steel.

[0022] Furthermore, when the shearing machine has reached the shearing limit, it also includes:

[0023] Determine the thickness h of the strip cut by the flying shear min ≤h i ≤h max Whether the condition is met;

[0024] If not, the output shear shear strip thickness is h i The width b(i) that can be sheared when using ultra-high strength steel, where h i is the strip thickness when the flying shear cuts ultra-high strength steel, i = 1, 2...n, h min h is the minimum thickness of the strip when the flying shear cuts ultra-high strength steel. max It is the maximum thickness of the strip when the flying shear cuts ultra-high strength steel.

[0025] Furthermore, when the shearing limit of the flying shear has not been reached, let j=j+1, β=β+1, and return to the step of executing the shearing work A consumed by the flying shear when transversely shearing the ultra-high strength steel.

[0026] The advantages and positive effects of the present invention are as follows: the present invention can determine the ultimate shearing capacity of the swing-type flying shear when shearing strip steel of corresponding thickness. When the unit produces strip steel products of various specifications, the shearing performance of the flying shear can be brought into play to the maximum extent, avoiding defects of poor cross-sectional quality due to exceeding the shearing capacity of the shearing equipment, thereby improving the actual production efficiency and quality and bringing economic benefits to the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 It is an overall flow chart of a method for evaluating the ultimate capacity of flying shear shearing ultra-high strength steel in an embodiment of the present invention;

[0029] Figure 2 is the calculation coefficient z and The changing relationship of

[0030] Figure 3 This is a curve diagram showing the change in the ultimate capacity of the flying shear for shearing 980DP ultra-high strength steel in an embodiment of the present invention;

[0031] Figure 4 This is a curve diagram of the ultimate capacity change of the flying shear in shearing 780Y ultra-high strength steel in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] Taking a swing shear as an example, combined with Figure 1 , a method for evaluating the ultimate capacity of ultra-high strength steel sheared by flying shear provided by the present invention is described in detail.

[0034] Example 1: The steel grade is 980DP.

[0035] Step A1, collect the shearing equipment parameters and strip steel specifications and performance related parameters during the shearing process of the swing flying shear: fixed length l = 0.5m during flying shear shearing, running speed v = 60m / min of the strip steel during flying shear working, inclination angle α of the shearing blade during flying shear working = 0.67°, rated power N of the flying shear e =130kW, power margin η when flying shear is working = 10%, relative value of gap between blades Y when flying shear is working = 0.07, relative distance of pressure plate X when flying shear is working = 1, strength of sheared strip σ b =1057MPa, elongation of sheared strip δ=11.7%.

[0036] Step B1: Define the total shear force P when the swing shear shears the strip and the pure shear force P when the shears shears the strip 1 , the bending force P of the sheared part of the rolled piece when the flying shear shears the strip 2 , the bending force P of the steel plate in the shearing area when the flying shear shears the strip 3 1. The blade blunting coefficient k = 1.3 when the flying shear cuts the strip. 2. The shearing work a done by the pure shearing of the unit length of the strip when the flying shear cuts the strip. 3. The time interval t between two shearings when the flying shear cuts the strip. 4. The shearing power N of the flying shear under the total shearing force when the flying shear cuts the strip. 5. The shearing power N allowed under safe conditions when the flying shear cuts the strip. 1 、Strip thickness h when flying shear shears ultra-high strength steel i (i=1, 2…n), strip width b when flying shear shears ultra-high strength steel j (i=1, 2…n), minimum strip thickness h when flying shears shear ultra-high strength steel min =0.5mm, maximum strip thickness h when flying shear shears ultra-high strength steel max =2.3mm, minimum strip width b when flying shears shear ultra-high strength steel min =800mm, the thickness of the strip steel cut by the flying shear is h i The maximum width b(i) (i=1, 2...n) that can be sheared when ultra-high strength steel is used, the optimized step length Δh of ultra-high strength steel strip thickness, the optimized step length Δb of ultra-high strength steel strip width, the strip thickness adjustment coefficient λ, and the strip width adjustment coefficient β.

[0037] Step C1, initialize the strip thickness adjustment coefficient λ=0, the strip width adjustment coefficient β=0, the strip thickness calculation times i=0, and the strip width calculation times j=0.

[0038] Step D1, determining the strip thickness optimization step length Δh=0.2 when shearing ultra-high strength steel, and the strip width optimization step length Δb=1 when shearing ultra-high strength steel.

[0039] Step E1: Calculate the pure shear force P of the swing shear when shearing ultra-high strength steel according to the calculation formula of the pure shear force of the oblique blade shear. 1 :

[0040]

[0041] Among them, K 1 =0.6, K 2 =1 is the conversion factor for calculating the shearing work per unit length of strip steel, and the shear thickness of ultra-high strength steel h is calculated. 0 =2.3mm, pure shear force P when flying shear shears ultra-high strength steel 1 =43.629kN.

[0042] Step F1: Based on the shearing theory of the swing shear, a shearing force calculation model of the inclined blade shear is constructed to calculate the total shearing force P when the shear shears shear ultra-high strength steel:

[0043]

[0044] Among them, Z = 0.95 is the calculation coefficient, which is related to the strip fracture elongation δ and the blade inclination angle α. The change relationship is as follows Figure 2 shown.

[0045] The total shear force P is calculated to be 188.22 kN when the flying shear shears ultra-high strength steel.

[0046] Step G1, based on the total shear force P obtained by the above calculation when the flying shear shears shear the ultra-high strength steel, calculate the shear work A consumed by the total shear force when shearing the ultra-high strength steel in the transverse direction:

[0047]

[0048] After calculation, the shear width b of ultra-high strength steel is obtained j =800mm, the shear work consumed by the total shear force when transversely shearing ultra-high strength steel is A=880.55N·m.

[0049] Step H1, based on the shearing work A consumed by the flying shear when shearing the ultra-high strength steel in the transverse direction obtained by the above calculation, the shearing power N of the swing flying shear when working continuously is calculated by measuring and collecting the running speed v and the fixed length l of the strip when the flying shear is working:

[0050]

[0051] Among them, ξ=20 takes into account the friction with air and other additional energy consumption coefficients in the shearing machine mechanism. The time interval between two shearings when the flying shear shears shear the strip is calculated to be t=0.5s, and the shearing power N=35.22kW when the flying shear shears shear the strip under the total shearing force.

[0052] Step I1: According to the rated power N of the shearing machine e =130kW and the power margin η of the flying shear is 10%, the shearing power N allowed under safe conditions when the flying shear is shearing the strip is calculated. 1 =N e (1-η)=117kW, and it can be concluded that N≤N 1 If it is established, it means that the shearing limit of the flying shear has not been reached. Let j = j + 1, β = β + 1, return to step G1, and calculate through loop calculation to obtain the shearing width b of the ultra-high strength steel. 1858=2658mm, the shearing power of the flying shear when shearing the strip under the total shearing force is N=117.03kW, and it can be judged that N≤N 1 Not true, let b(0) = b 1857 =2657mm.

[0053] Step J1: Determine the thickness h of the strip cut by the flying shear min ≤h i ≤h max Whether the condition is established, after calculation, if the constraint condition is satisfied, save the strip steel specification data, set i=i+1, λ=λ+1, return to step E1, and perform the next strip steel specification shear limit capacity evaluation calculation.

[0054] Step K1: Output flying shear cuts the strip with a thickness of h i The maximum width b(i) that can be sheared when using ultra-high strength steel.

[0055] In this embodiment, a swing-type flying shear and steel grade 980DP are used as research objects to obtain the limit shear width corresponding to different incoming material thicknesses, as shown in Table 1. By comparing the shear parameter changes before and after the application of the evaluation method for the ultimate capacity of flying shear shearing ultra-high strength steel provided by the present invention, the ultimate capacity change curve of flying shear shearing ultra-high strength steel is obtained, as shown in Table 1. Figure 3 As the thickness of the incoming strip decreases, the maximum width that the flying shear can shear gradually increases. The maximum specifications of the strip that the flying shear can shear are determined to maximize the shearing capacity of the flying shear and ensure the shearing quality of the strip.

[0056] Table 1

[0057]

[0058] Embodiment 2: The steel grade is 780Y.

[0059] Step A2, collect the shearing equipment parameters and strip steel specifications and performance related parameters during the shearing process of the swing flying shear: fixed length l = 0.5m during flying shear shearing, running speed v = 60m / min of the strip steel during flying shear working, inclination angle α of the shearing blade during flying shear working = 0.67°, rated power N of the flying shear e =130kW, power margin η when flying shear is working = 10%, relative value of gap between blades Y when flying shear is working = 0.07, relative distance of pressure plate X when flying shear is working = 1, strength of sheared strip σ b =849MPa, elongation of sheared strip δ=18.9%.

[0060] Step B2: Define the total shear force P when the swing shear shears the strip and the pure shear force P when the shears shears the strip 1 , the bending force P of the sheared part of the rolled piece when the flying shear shears the strip 2, the bending force P of the steel plate in the shearing area when the flying shear shears the strip 3 1. The blade blunting coefficient k = 1.3 when the flying shear cuts the strip. 2. The shearing work a done by the pure shearing of the unit length of the strip when the flying shear cuts the strip. 3. The time interval t between two shearings when the flying shear cuts the strip. 4. The shearing power N of the flying shear under the total shearing force when the flying shear cuts the strip. 5. The shearing power N allowed under safe conditions when the flying shear cuts the strip. 1 、Strip thickness h when flying shear shears ultra-high strength steel i (i=1, 2…n), strip width b when flying shear shears ultra-high strength steel j (i=1, 2…n), minimum strip thickness h when flying shears shear ultra-high strength steel min =0.5mm, maximum strip thickness h when flying shear shears ultra-high strength steel max =2.3mm, minimum strip width b when flying shears shear ultra-high strength steel min =800mm, the thickness of the strip steel cut by the flying shear is h i The maximum width b(i) (i=1, 2...n) that can be sheared when ultra-high strength steel is used, the optimized step length Δh of ultra-high strength steel strip thickness, the optimized step length Δb of ultra-high strength steel strip width, the strip thickness adjustment coefficient λ, and the strip width adjustment coefficient β.

[0061] Step C2, initialize the strip thickness adjustment coefficient λ=0, the strip width adjustment coefficient β=0, the strip thickness calculation times i=0, and the strip width calculation times j=0.

[0062] Step D2, determining the strip thickness optimization step length Δh=0.2 when shearing ultra-high strength steel, and the strip width optimization step length Δb=1 when shearing ultra-high strength steel.

[0063] Step E2: Calculate the pure shear force P when the swing shear shears shears ultra-high strength steel according to the calculation formula of the pure shear force of the oblique blade shear. 1 :

[0064]

[0065] Among them, K 1 =0.6, K 2 =1 is the conversion factor for calculating the shearing work per unit length of strip steel, and the shear thickness of ultra-high strength steel h is calculated. 0 =2.3mm, pure shear force P when flying shear shears ultra-high strength steel 1 =56.61kN.

[0066] Step F2: Based on the shearing theory of the swing shear, a shearing force calculation model of the inclined blade shear is constructed to calculate the total shearing force P when the shear shears shear the ultra-high strength steel:

[0067]

[0068] Among them, Z = 0.95 is the calculation coefficient, which is related to the fracture elongation δ of the strip steel and the blade inclination angle α. The total shear force P = 237.27 kN is calculated when the flying shear shears ultra-high strength steel.

[0069] Step G2: Calculate the shearing work A consumed by the total shearing force when the ultra-high-strength steel is sheared transversely based on the total shearing force P obtained by the above calculation:

[0070]

[0071] After calculation, the shear width b of ultra-high strength steel is obtained j =800mm, the shear work consumed by the total shear force when transversely shearing ultra-high strength steel is A=1110.02N·m.

[0072] Step H2, based on the shearing work A consumed by the flying shear when shearing the ultra-high strength steel in the transverse direction obtained by the above calculation, the shearing power N of the swing flying shear when working continuously is calculated by measuring and collecting the running speed v and the fixed length l of the strip when the flying shear is working:

[0073]

[0074] Among them, ξ=20 takes into account the friction with air and other additional energy consumption coefficients in the shearing machine mechanism. The time interval between two shearings when the flying shear shears shear the strip is calculated to be t=0.5s, and the shearing power N=44.4kW when the flying shear shears shear the strip under the total shearing force.

[0075] Step I2: According to the rated power N of the shearing machine e =130kW and the power margin η of the flying shear is 10%, the shearing power N allowed under safe conditions when the flying shear is shearing the strip is calculated. 1 =N e (1-η)=117kW, and it can be concluded that N≤N 1 If it is established, it means that the shearing limit of the flying shear has not been reached. Let j = j + 1, β = β + 1, return to step G2, and calculate through loop calculation to obtain the shearing width b of the ultra-high strength steel. 1309 =2109mm, the shearing power of the flying shear when shearing the strip under the total shearing force is N=117.05kW, and it can be judged that N≤N 1 Not true, let b(0) = b 1308 =2108mm.

[0076] Step J2: Determine the thickness h of the strip cut by the flying shear min ≤h i ≤h maxWhether the conditions are met, after calculation, the constraints are met, and the strip steel specification data is saved. Let i=i+1, λ=λ+1, substitute it into step (E) and perform the next strip steel specification shear limit capacity evaluation calculation.

[0077] Step K2: Output flying shear shears the strip to a thickness of h i The maximum width b(i) that can be sheared when using ultra-high strength steel.

[0078] In this embodiment, the swing-type flying shear and steel grade 780Y are used as research objects to obtain the limit shear width corresponding to different incoming material thicknesses, as shown in Table 2. By comparing the shear parameter changes before and after the application of the evaluation method for the ultimate capacity of flying shear shearing ultra-high strength steel provided by the present invention, the ultimate capacity change curve of flying shear shearing ultra-high strength steel is obtained, as shown in Table 2. Figure 4 As shown, as the thickness of the incoming strip decreases, the maximum width that the flying shear can shear gradually increases. The maximum specification of the strip that the flying shear can shear is determined to maximize the shearing capacity of the flying shear and ensure the shearing quality of the strip.

[0079] Table 2

[0080]

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the ultimate capacity of ultra-high strength steel sheared by a flying shear, characterized in that: include: Step A, obtain the shearing equipment parameters, strip steel specifications and performance parameters during the shearing process of the swing-type flying shear: the fixed length l of the flying shear during shearing, the running speed v of the strip steel during the flying shear operation, the inclination angle α of the shear blade during the flying shear operation, and the rated power N of the flying shear. e , power margin η when the flying shear is working, relative value Y of the gap between the blades when the flying shear is working, relative distance X of the pressure plate when the flying shear is working, strength σ of the sheared strip b , elongation of the sheared strip δ; Step B, initializing the strip thickness adjustment coefficient λ, the strip width adjustment coefficient β, the strip thickness calculation times i and the strip width calculation times j; determining the strip thickness optimization step length Δh when shearing ultra-high strength steel, and the strip width optimization step length Δb when shearing ultra-high strength steel; Step C, calculating the pure shear force P1 when the swing shear shears shear the ultra-high strength steel according to the calculation formula of the pure shear force of the oblique blade shear; Step D: According to the shearing theory of the oblique blade shearing machine, a shearing force calculation model of the oblique blade shearing machine is established to calculate the total shearing force P when the flying shear shears shear the ultra-high strength steel: Among them, P2 is the bending force of the sheared part of the rolled piece when the flying shear shears the strip, and P3 is the bending force of the steel plate in the shearing area when the flying shear shears shear the strip; is the calculation coefficient, which is related to the strip width b, thickness h, strip elongation at break δ and blade inclination angle α; Step E: Calculate the shearing work A consumed by the total shearing force when the ultra-high-strength steel is sheared transversely according to the total shearing force P when the flying shear shears shear the ultra-high-strength steel. The calculation formula is: Among them, b j b is the strip width when the flying shear cuts ultra-high strength steel, j =b min +βΔb,b min is the minimum strip width when the flying shear cuts ultra-high strength steel, β is the strip width adjustment coefficient, and Δb is the optimization step length of ultra-high strength steel strip width; Step F: According to the shearing work A consumed by the flying shear when transversely shearing the ultra-high-strength steel, the shearing power N of the swing flying shear when working continuously is calculated by measuring and collecting the running speed v and the fixed length l of the strip when the flying shear is working. The calculation formula is: Among them, t is the time interval between two shearings when the flying shear cuts the strip steel, ξ is the friction with air and other additional energy consumption coefficients in the shearing machine mechanism; Step G: According to the rated power N of the shearing machine e and the power margin η when the flying shear is working, the shearing power N1=N allowed under safe conditions when the flying shear is shearing the strip is calculated e (1-η), and determine whether N≤N1 is established. If so, it means that the shearing limit of the flying shear has not been reached. Otherwise, it means that the flying shear has reached the shearing limit.

2. The method for evaluating the ultimate capacity of ultra-high strength steel sheared by a flying shear according to claim 1, characterized in that: The calculation formula of pure shear force of oblique blade shearing machine is: Among them, h i =h max -λΔh;h max h is the maximum thickness of the strip when the flying shear cuts ultra-high strength steel; i is the strip thickness when the flying shear shears shear ultra-high strength steel, i=1, 2…n, n is the final number of cycles of the strip width, k is the blade passivation coefficient when the flying shears shears shear the strip, K1 and K2 are conversion coefficients for calculating the shearing work of shearing unit length of strip.

3. The method for evaluating the ultimate capacity of ultra-high strength steel sheared by a flying shear according to claim 1, characterized in that: When the flying shear has reached the shearing limit, the strip width b(i) when the flying shear cuts the ultra-high strength steel is = b j-1 , b(i) is the strip thickness h i The maximum width that the shear can cut is saved.

4. The method for evaluating the ultimate capacity of ultra-high strength steel sheared by a flying shear according to claim 3, characterized in that: When the shearing machine has reached the shearing limit, it also includes: Determine the thickness h of the strip cut by the flying shear min ≤h i ≤h max Whether the condition is met; If it is established, let i = i + 1, λ = λ + 1, and return to the step of calculating the pure shear force P1 when the swing shear shears the ultra-high strength steel, where h i is the strip thickness when the flying shear cuts ultra-high strength steel, i = 1, 2…n, n is the strip width and the final number of cycles, h min h is the minimum thickness of the strip when the flying shear cuts ultra-high strength steel. max It is the maximum thickness of the strip when the flying shear cuts ultra-high strength steel.

5. The method for evaluating the ultimate capacity of ultra-high strength steel sheared by a flying shear according to claim 3, characterized in that: When the shearing machine has reached the shearing limit, it also includes: Determine the thickness h of the strip cut by the flying shear min ≤h i ≤h max Whether the condition is met; If not, the output shear shear strip thickness is h i The width b(i) that can be sheared when using ultra-high strength steel, where h i is the strip thickness when the flying shear cuts ultra-high strength steel, i = 1, 2...n, h min h is the minimum thickness of the strip when the flying shear cuts ultra-high strength steel. max It is the maximum thickness of the strip when the flying shear cuts ultra-high strength steel.

6. The method for evaluating the ultimate capacity of ultra-high strength steel sheared by a flying shear according to claim 1, characterized in that: When the shearing limit of the flying shear has not been reached, let j=j+1, β=β+1, and return to the step of executing the shearing work A consumed by the flying shear when transversely shearing the ultra-high strength steel.

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