Cast strand surface crack prediction method and apparatus, device and medium

Abstract

The present invention relates to the technical filed of steel continuous casting, and provides a cast strand surface crack prediction method and apparatus, a device and a medium. The method comprises: on the basis of an obtained test critical strain value and a strain influence factor, determining an actual critical strain value, wherein the strain influence factor comprises a grain size factor, a solute segregation factor and a notch factor; on the basis of obtained material properties, machine parameters and process conditions, determining a critical strain rate; and on the basis of the actual critical strain value and the critical strain rate, using a damage integral method to generate a crack prediction result. By considering factors influencing crack formation, the present invention provides a more accurate prediction method, which not only does not require a large amount of experimental data, but also does not require technicians to have casting experience, thereby greatly reducing the prediction cost.

Description

A method, device, equipment and medium for predicting surface cracks of a casting blank TECHNICAL FIELD

[0001] The present application relates to the technical field of steel continuous casting, in particular to a method, device, equipment and medium for predicting surface cracks of a casting blank. BACKGROUND

[0002] In the steel continuous casting process, surface cracks of a casting blank are an important problem because their occurrence significantly increases the cost of adjusting and repairing the casting blank before rolling, and can transmit defects to subsequent rolling products, affecting product quality. Severe cracks can also cause the casting blank to be scrapped or cause a breakout phenomenon, which will interrupt the casting operation process and cause the need for equipment maintenance, resulting in waste of time and resources. The formation of cracks is mainly caused by two factors: one is the brittleness characteristics of steel in a specific temperature range, which is a physical property of the material itself; the other is the complex strain and stress state caused by specific solidification conditions in the casting process, which together exacerbate the occurrence and development of cracks.

[0003] In the prior art, a tensile test is generally used to evaluate the sensitivity of different steel grades to cracks, which is carried out under strictly controlled parameters such as deformation temperature and strain rate, to determine the relationship between the reduction of area of the steel grade and the temperature on the casting machine, so as to predict the occurrence of surface cracks of the casting blank according to the relationship between the reduction of area and the temperature and the casting experience of the technician, and then adjust the surface temperature of the round blank when passing through the key machine area to prevent the occurrence of surface cracks of the casting blank. Although this method can predict the occurrence of surface cracks of the casting blank, this method requires the technician to have considerable casting experience and a large amount of experimental data, and the relationship between the reduction of area and the temperature of the steel grade on different casting machines is also different. Each casting machine needs multiple experiments to obtain the relationship between the reduction of area and the temperature, resulting in a high cost of predicting surface cracks of the casting blank. SUMMARY

[0004] The problem solved by the present application is how to reduce the prediction cost of surface cracks of a casting blank.

[0005] To solve the above problems, in a first aspect, the present application provides a method for predicting surface cracks of a casting blank, comprising:

[0006] determining an actual critical strain value according to the obtained test critical strain value and a strain influencing factor, wherein the strain influencing factor includes a grain size factor, a composition segregation factor and a notch factor;

[0007] determining a critical strain rate according to the obtained material properties, machine parameters and process conditions;

[0008] According to the actual critical strain value and the critical strain rate, a crack prediction result is generated by using a damage integral method.

[0009] Optionally, the generating the crack prediction result according to the actual critical strain value and the critical strain rate by using the damage integral method comprises:

[0010] A deformation time of the surface of the casting blank is obtained, and the deformation time is divided into at least two sub-deformation times.

[0011] According to the actual critical strain value and the critical strain rate, a sub-surface damage of each of the sub-deformation times is determined by using the damage integral method, and a total surface damage is generated according to all the sub-surface damages.

[0012] The crack prediction result is generated according to the total surface damage.

[0013] Optionally, the generating the crack prediction result according to the total surface damage comprises:

[0014] The crack prediction result is generated according to the total surface damage by using a cracking criterion formula, and the cracking criterion formula comprises:

[0015] wherein t1 is a start time, t is the sub-deformation time, is the critical strain rate, and εcrit is the actual critical strain value, is the total surface damage.

[0016] Optionally, the determining the actual critical strain value according to the obtained test critical strain value and a strain influence factor comprises:

[0017] The actual critical strain value is determined according to the test critical strain value and the strain influence factor by using an actual critical strain value formula, and the actual critical strain value formula comprises:

[0018] wherein ε crit is the actual critical strain value, ε crit (tensile test) is the test critical strain value, f grainsize is the grain size factor, fsegregation is the composition segregation factor, and f notch is the notch factor.

[0019] Optionally, the determining the critical strain rate according to the obtained material properties, machine parameters and process conditions comprises:

[0020] According to the material property, the machine parameter and the process condition, the critical strain rate is determined by using a critical strain rate formula, and the critical strain rate formula comprises:

[0021] Wherein, The critical strain rate is R, the casting radius of the machine parameter is R, the radius direction coordinate of the machine parameter is x, and the origin is located at the center of the casting machine, v c The casting speed of the process condition is v, the material property is Z, and the coefficient is C. The casting radius R of the machine parameter is the rate of change of the material property Z.

[0022] Optionally, before the actual critical strain value is determined according to the obtained test critical strain value and the strain influence factor, the method further comprises:

[0023] According to the existing test data, the area reduction is determined.

[0024] According to the area reduction, the test critical strain value is determined.

[0025] Optionally, the test critical strain value is determined according to the area reduction, comprising:

[0026] According to the area reduction, the test critical strain value is determined by using a test critical strain value formula group, and the test critical strain value formula group comprises:

[0027] Wherein, the area reduction is RA, the casting blank diameter before the test is D0, the casting blank fracture diameter before the test is D f The casting blank fracture diameter before the test is D.

[0028] In a second aspect, the present application provides a casting blank surface crack prediction device, comprising:

[0029] The actual critical strain value module is used for determining the actual critical strain value according to the obtained test critical strain value and the strain influence factor, wherein the strain influence factor comprises a grain size factor, a composition segregation factor and a notch factor.

[0030] The critical strain rate module is used for determining the critical strain rate according to the obtained material property, machine parameter and process condition.

[0031] The loss prediction module is used for generating a crack prediction result by using a damage integral method according to the actual critical strain value and the critical strain rate.

[0032] In a third aspect, the present application provides an electronic device comprising a memory and a processor.

[0033] the memory, configured to store a computer program;

[0034] the processor, configured to, when executing the computer program, implement the method for predicting surface cracks of a casting blank according to the first aspect.

[0035] In a fourth aspect, the present application provides a computer readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the method for predicting surface cracks of a casting blank according to the first aspect is implemented.

[0036] The method for predicting surface cracks of a casting blank, the device, the electronic equipment and the storage medium have the following beneficial effects:

[0037] According to the obtained test critical strain value and strain influence factor, the actual critical strain value is determined, various influence factors, i.e., a grain size factor, a composition segregation factor and a notch factor, are considered, the material behavior in the actual production environment can be more accurately reflected, the accuracy of crack prediction is improved, meanwhile, the number of unnecessary experiments is reduced, and the trial and error cost is reduced. According to the obtained material properties, machine parameters and process conditions, the critical strain rate of the straightening and bending strain of the casting blank can be determined, the influence of the straightening and bending strain of the casting blank on the surface cracks of the casting blank can be considered in subsequent analysis. Finally, the damage integral method is adopted, the actual critical strain value and the critical strain rate are applied to the transient condition to evaluate the damage accumulation of the casting blank in the continuous casting process, so as to predict the possibility of cracking, and an accurate crack prediction result is obtained. The present application provides a more accurate prediction method by comprehensively considering various factors influencing crack formation, the requirement for the number of experimental data and the casting experience of technical personnel is reduced, and the prediction cost of the surface cracks of the casting blank is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0038] Fig. 1 is a flowchart of the method for predicting surface cracks of a casting blank provided by the embodiment of the present application;

[0039] Fig. 2 is a structural schematic diagram of the device for predicting surface cracks of a casting blank provided by the embodiment of the present application;

[0040] Fig. 3 is a structural schematic diagram of the electronic equipment provided by the embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be interpreted as being limited to the embodiments set forth herein, but rather these embodiments are provided so as to more thoroughly and completely understand the present application. It should be understood that the drawings and embodiments of the present application are merely for illustrative purposes and are not intended to limit the scope of the present application.

[0042] It should be understood that each of the steps recited in the method embodiments of the present application can be performed in different orders and / or in parallel. In addition, the method embodiments can include additional steps and / or omit the steps shown. The scope of the present application is not limited in this respect.

[0043] As used herein, the term "includes" and its variants are open-ended, meaning "includes but is not limited to"; the term "based on" means "based, at least in part, on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments." Related terms will be understood analogously. It should be noted that references herein to "first" "second" and the like indicate different apparatuses, modules or units and do not imply that the functions of these apparatuses, modules or units are performed in the order in which they are described.

[0044] It should be noted that the terms "one" and "a" and "multiple" are used in the sense of "one or more" unless otherwise indicated in the context. The skilled person will understand that "one" or "a" or "multiple" should be interpreted as "one or more" unless the context clearly dictates otherwise.

[0045] The names of the messages or information exchanged between the various apparatuses in the embodiments of the present application are merely for illustrative purposes and are not intended to limit the scope of the messages or information.

[0046] In the steel continuous casting process, the appearance of surface cracks in the cast slab is considered an extremely unfavorable condition, as it not only significantly increases the economic cost of adjusting and repairing the cast slab before rolling, but also harbors the risk of transmitting defects to subsequent rolling products, thereby affecting product quality. If the existence of such cracks is ignored, severe cracks can even force the cast slab to be scrapped, and worse still, severe cracks can also cause the phenomenon of breakout, which will directly interrupt the casting process and cause the need for maintenance of production equipment, resulting in a waste of time and resources. The root cause of the formation of cracks can be attributed to two factors: one is the brittle characteristics exhibited by the steel material in a specific temperature range, which is a physical property inherent to the material; the other is the complex strain and stress state produced by specific solidification conditions during the casting process, which together exacerbate the possibility of crack initiation and propagation. In order to accurately assess the sensitivity of different steel grades to cracks, the industry generally uses tensile testing as a standard method, which is carried out under strict control of parameters such as deformation temperature and strain rate, with the reduction of area after specimen fracture as the key indicator to measure the ductility of the cast slab material. When the reduction of area is low, it means that the cast slab material is prone to tearing during the tensile process, exhibiting high brittleness; on the contrary, if the reduction of area value is close to 100%, it indicates that the cast slab material has undergone significant shrinkage (i.e. the final cross-sectional area after fracture is small), with good ductility.

[0047] Based on the above relationship between reduction of area and temperature, the technicians of the continuous casting plant can adjust the surface temperature of the cast slab as it passes through the key machine area to ensure that it has sufficient ductility, thereby effectively preventing the formation of cracks. Studies have shown that for a specific round billet grade, when the round billet surface temperature is maintained within a specific temperature range that makes the reduction of area greater than 75%, it can significantly reduce the occurrence of bending cracks and network cracks on the specific machine. Therefore, in actual operation, by implementing a low-temperature intensive cooling strategy (usually below 700°C), it can ensure that this type of steel material is successfully cast on a specific casting machine without worrying about the problem of cracks. Therefore, the reduction of area and temperature relationship chart is successfully applied in many factories to optimize secondary cooling to avoid certain types of cracks. However, this simple method requires a considerable amount of casting experience and a large amount of crack data to establish the relationship between the crack problem occurring on the casting machine and the experimental reduction of area and temperature curve, and this relationship is different for each machine. Therefore, the prediction method of the prior art is too complex and requires a large amount of data, which is too costly.

[0048] In addition, there are some difficulties in directly applying the relationship between the reduction of area and temperature to the actual continuous casting. In the continuous casting process, the surface temperature and the strain rate of the casting blank, for example, a round blank, change along the round blank. Therefore, the deformation of the round blank occurs under variable thermal mechanical conditions, while the deformation in the tensile test is usually carried out at a constant temperature and a constant strain rate, and thus the existing prediction method has low accuracy.

[0049] In view of the problems in the related art described above, the embodiment provides a method, device, equipment and medium for predicting surface cracks of a casting blank.

[0050] As shown in FIG. 1, the method for predicting surface cracks of a casting blank provided by the embodiment of the application comprises the following steps.

[0051] According to the obtained test critical strain value and the strain influencing factor, the actual critical strain value is determined, wherein the strain influencing factor comprises a grain size factor, a composition segregation factor and a notch factor.

[0052] Specifically, the test critical strain value is obtained through existing test data. The test critical strain value is a key parameter obtained from the stress-strain curve of the tensile test. It represents a specific strain point, at which, although the material rapidly shrinks, the microstructure difference between the constrained part and the unconstrained part of the sample remains small due to the uniform temperature and the same way of microstructure development (especially the nitride precipitation along the austenite grain boundary in the length direction of the sample). In simple terms, the test critical strain value measures the degree of uniform longitudinal strain experienced by the tensile sample before it breaks. The formation of surface cracks of the casting blank is the result of the joint action of multiple factors. In addition to known factors, local changes in austenite grain size, composition segregation in the oscillation mark area, and the notch effect caused by the oscillation mark itself are also important crack promoting factors. In particular, transverse cracks are more common in the oscillation mark, where the gap thickens, the cooling speed in the mold slows down, and the inhomogeneity of thermal strain distribution is caused. Therefore, the grain size factor, the composition segregation factor and the notch factor are combined with the test critical strain value to determine the actual critical strain value which is more complex but closer to the actual situation, thereby providing more accurate theoretical support for the prediction of surface cracks of the casting blank.

[0053] According to the obtained material properties, machine parameters and process conditions, the critical strain rate is determined.

[0054] In particular, the formation of transverse surface cracks in the slab is mainly attributed to the complex interaction of thermal strains with the straightening and bending strains of the slab. When the surface material cools significantly faster than the underlying material, a significant thermal tensile strain is generated, which causes the surface of the slab to tend to contract. However, since the underlying material cools more slowly, it constrains the surface material from freely contracting. In other words, the formation of transverse corner cracks is directly caused by this difference in thermal strains, since the corner regions tend to cool faster than the adjacent slab surface due to the geometry and heat dissipation conditions. These corner regions tend to contract in the longitudinal direction, but are constrained by the surface material and cannot do so, resulting in a total strain that tends to zero (or very close to zero). In order to maintain this strain balance, viscoplastic (creep) strains intervene to offset the effects of thermal strains, so that the influence of thermal strains on the critical strain rate can be disregarded. As for the straightening and bending strains of the slab, their generation and magnitude are highly dependent on the specific type and design of the continuous casting machine. In round arc type continuous casting machines that use a curved mold, the straightening process usually occurs at the end of the machine. However, in some designs, the straightening process can already begin below the mold in order to reduce subsequent straightening stresses. Therefore, given the material properties, machine parameters and process conditions, the strain rates generated during the straightening and bending of the slab can be determined.

[0055] According to the actual critical strain value and the critical strain rate, a crack prediction result is generated using a damage integral method.

[0056] In particular, the core of the damage integral method is to flexibly and ingeniously apply the critical strain data determined under isothermal conditions, i.e. the actual critical strain value and the critical strain rate, to the more complex transient continuous casting conditions, thereby constructing a prediction criterion for the surface cracking of the continuous casting slab, and further generating a crack prediction result.

[0057] In this embodiment, the actual critical strain value is determined according to the obtained test critical strain value and strain influencing factors, various influencing factors, i.e., grain size factor, composition segregation factor and notch factor, are considered, the material behavior in the actual production environment can be more accurately reflected, the accuracy of crack prediction is improved, meanwhile, the number of unnecessary experiments is reduced, and the trial and error cost is reduced. According to the obtained material properties, machine parameters and process conditions, the critical strain rate of the straightening and bending strain of the casting blank can be determined, which is convenient for considering the influence of the straightening and bending strain of the casting blank on the surface cracks of the casting blank in subsequent analysis. Finally, the damage integral method is used to apply the actual critical strain value and the critical strain rate to the transient condition to evaluate the damage accumulation of the casting blank in the continuous casting process, so as to predict the possibility of cracking and obtain accurate crack prediction results. The present application provides a more accurate prediction method by comprehensively considering various factors influencing crack formation, which not only does not require a large amount of experimental data, but also does not require the technical personnel to have casting experience, thereby greatly reducing the prediction cost.

[0058] Optionally, the damage integral method is used to generate a crack prediction result according to the actual critical strain value and the critical strain rate, comprising:

[0059] The deformation time of the casting blank surface is obtained, and the deformation time is divided into at least two sub-deformation times;

[0060] According to the actual critical strain value and the critical strain rate, the damage integral method is used to determine the sub-surface damage of each sub-deformation time, and the total surface damage is generated according to all the sub-surface damages;

[0061] The crack prediction result is generated according to the total surface damage.

[0062] Specifically, the deformation time refers to the time required for the surface element of the casting blank to pass through the continuous casting machine, the deformation time is divided into a series of small sub-deformation times, in each sub-deformation time, the amount of "damage" suffered by the surface element is calculated, i.e., the sub-surface damage, and all the sub-surface damages are accumulated to obtain the total surface damage, which is used as the basis for evaluating the prediction of cracks to obtain the crack prediction result.

[0063] Optionally, the crack prediction result is generated according to the total surface damage, comprising:

[0064] According to the total surface damage, a cracking criterion formula is used to generate the crack prediction result, the cracking criterion formula comprises:

[0065] Wherein, t1 is the start time, t is the sub-deformation time, is the critical strain rate, and crit is the actual critical strain value, for the total surface damage.

[0066] In particular, the start time can be defined as the time at which the cross-sectional reduction reaches a certain value, for example, the time at which it reaches 75%. The accumulated damage of the surface of the casting blank is:

[0067] where L is also the total surface damage, and the accumulated strain is:

[0068] Therefore, the accumulated strain can also be expressed as Lε crit Thus, it can be determined that cracking will occur if the accumulated strain is equal to ε crit at which time L = 1, thus obtaining the cracking criterion formula, which determines the parameter crack when the total surface damage is greater than or equal to 1.

[0069] Illustratively, in the above formula, the increment of the deformation strain, i.e., the increment of the surface damage, is given different weights, which are determined based on the ratio of the actual conditions present within a certain time step to the corresponding critical strain, such as temperature, strain rate, etc. This weighting method aims to more accurately reflect the contribution of strain to material damage under different conditions. In addition, according to the in-depth understanding of a particular cracking mechanism, the strain rate can be selectively applied to further refine the damage assessment. Specifically, both the absolute value of the strain rate can be used to assume the consistency of microscopic slip and aluminum particle precipitation behavior in tensile and compressive deformation, or only the tensile strain rate can be considered, or both the tensile and compressive strain rates can be considered but given different weighting factors. This flexibility enables the damage integral method to be more closely related to actual working conditions, improving the accuracy and reliability of cracking prediction.

[0070] Optionally, determining the actual critical strain value according to the obtained test critical strain value and strain influence factor comprises:

[0071] According to the test critical strain value and the strain influence factor, determining the actual critical strain value by using an actual critical strain value formula, the actual critical strain value formula comprising:

[0072] where ε crit is the actual critical strain value, ε crit (tensile test) is the test critical strain value, f grainsize is the grain size factor, fsegregation is the composition segregation factor, and f notch is the notch factor.

[0073] Specifically, by considering the actual critical strain value formula of the local variation of austenite grain size, the composition segregation of oscillation trace area and the notch effect of the oscillation trace itself on the material, a more actual critical strain value can be determined to facilitate more accurate crack prediction.

[0074] Optionally, the determining the critical strain rate according to the obtained material property, machine parameter and process condition comprises:

[0075] According to the material property, the machine parameter and the process condition, a critical strain rate formula is used to determine the critical strain rate, and the critical strain rate formula comprises:

[0076] wherein, is the critical strain rate, R is the caster radius of the machine parameter, x is the radius direction coordinate of the machine parameter, and the origin is located at the center of the caster, v c is the casting speed of the process condition, Z is the material property, C is a coefficient, is the change rate of the caster radius R with the material property Z.

[0077] Specifically, according to the critical strain rate formula considering the material property, machine parameter and process condition, an accurate critical strain rate can be obtained. Wherein, R-x is the distance.

[0078] Optionally, before the determining the actual critical strain value according to the obtained test critical strain value and strain influencing factor, further comprising:

[0079] According to the existing test data, the area reduction is determined;

[0080] According to the area reduction, the test critical strain value is determined.

[0081] Specifically, according to the existing test data, such as existing tensile test, the stress-strain curve is obtained to determine the area reduction, and then the test critical strain value is derived.

[0082] Optionally, the determining the test critical strain value according to the area reduction comprises:

[0083] According to the area reduction, a test critical strain value formula group is used to determine the test critical strain value, and the test critical strain value formula group comprises:

[0084] wherein, RA is the area reduction, D0 is the diameter of the casting blank before the test, D f is the diameter of the casting blank fracture before the test.

[0085] Specifically, by using the test critical strain value formula set, an accurate test critical strain value can be derived. For example, the RA can also be determined according to the theoretical formula:

[0086] wherein a, b, c and d are coefficients, T is a deformation temperature, T f is a temperature corresponding to a reduction of area of 100%.

[0087] For example, the present application provides a specific example to explain the prediction process of the prediction method of the surface crack of the casting blank. The casting blank is taken as a round blank with a diameter of 300 mm, and the material composition includes 0.25% carbon, 0.12% silicon, 2.1% manganese, 0.035% phosphorus and 0.0036% sulfur. The drawing speed is 1.5 m / min, and the casting machine radius is 12 m. First, the reduction of area and the test critical strain value are determined according to the test critical strain value formula set or the test critical strain value formula in the test critical strain value formula set and the theoretical formula, and then the actual critical strain value is obtained by using the actual critical strain value formula according to the reduction of area and the test critical strain value. Then, the critical strain rate is determined according to each parameter, and the maximum critical strain rate is about 3*10 -3 s -1 Finally, the total surface damage is calculated according to the actual critical strain value and the critical strain rate. Therefore, the prediction result is that there is a risk of cracking.

[0088] As shown in FIG. 2, the prediction device 200 for the surface crack of the casting blank provided by the embodiment of the present application comprises:

[0089] The actual critical strain value module 210 is configured to determine the actual critical strain value according to the obtained test critical strain value and the strain influence factor, wherein the strain influence factor includes a grain size factor, a composition segregation factor and a notch factor.

[0090] The critical strain rate module 220 is configured to determine the critical strain rate according to the obtained material properties, machine parameters and process conditions.

[0091] The loss prediction module 230 is configured to generate a crack prediction result by using the damage integral method according to the actual critical strain value and the critical strain rate.

[0092] As shown in FIG. 3, the electronic device 300 provided by the embodiment of the present application comprises a memory 310 and a processor 320. The memory 310 is configured to store a computer program. The processor 320 is configured to implement the prediction method of the surface crack of the casting blank as described above when the computer program is executed.

[0093] Or, an electronic device 300, comprising a memory 310 and a processor 320 coupled to the memory 310; the memory 310 is configured to store a computer program; the processor 320 is configured to execute the following operations when executing the computer program:

[0094] According to the obtained test critical strain value and strain influence factor, determine the actual critical strain value, wherein the strain influence factor includes grain size factor, composition segregation factor and notch factor;

[0095] According to the obtained material properties, machine parameters and process conditions, determine the critical strain rate;

[0096] According to the actual critical strain value and the critical strain rate, using damage integral method, generate crack prediction results. The computer readable storage medium provided by the embodiment of the application, the storage medium stores a computer program, when the computer program is executed by the processor, the prediction method of the surface crack of the casting blank is realized.

[0097] Or, a non-volatile computer readable storage medium, the storage medium stores a computer program, when the computer program is executed by the processor, the processor executes the following operations:

[0098] According to the obtained test critical strain value and strain influence factor, determine the actual critical strain value, wherein the strain influence factor includes grain size factor, composition segregation factor and notch factor;

[0099] According to the obtained material properties, machine parameters and process conditions, determine the critical strain rate;

[0100] According to the actual critical strain value and the critical strain rate, using damage integral method, generate crack prediction results.

[0101] Now will be described as the electronic device 300 of the server or client of the present application, it is the example of the hardware device that can be applied to each aspect of the present application. Electronic device 300 is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic device 300 can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are merely examples and are not intended to limit implementations of the present application described and / or claimed herein.

[0102] The electronic device 300 includes a computing unit that can perform various appropriate actions and processes in accordance with a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). Various programs and data required for device operation can also be stored in the RAM. The computing unit, the ROM, and the RAM are connected to each other through a bus. An input / output (I / O) interface is also connected to the bus.

[0103] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, the processes of the above-mentioned embodiments can be included. The storage medium can be a magnetic disc, an optical disc, a read-only memory (ROM), a random access memory (RAM), or the like. In this application, the units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place or distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application. In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0104] Although the present application is disclosed as above, the protection scope of the present application is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and these changes and modifications will fall within the protection scope of the present application.

Claims

1. A method of predicting surface cracks of a cast slab, characterized by, The method comprises the following steps: According to the obtained test critical strain value and strain influence factor, the actual critical strain value is determined, wherein the strain influence factor includes grain size factor, composition segregation factor and notch factor; According to the obtained material properties, machine parameters and process conditions, the critical strain rate is determined; According to the actual critical strain value and the critical strain rate, the damage integral method is used to generate the crack prediction result.

2. The method of predicting surface cracks of a cast slab according to claim 1, characterized by, The method according to the actual critical strain value and the critical strain rate, using the damage integral method to generate the crack prediction result, comprises the following steps: Obtain the deformation time of the slab surface, and divide the deformation time into at least two sub-deformation times; According to the actual critical strain value and the critical strain rate, the damage integral method is used to determine the sub-surface damage of each sub-deformation time, and the total surface damage is generated according to all sub-surface damages; According to the total surface damage, the crack prediction result is generated.

3. The method of predicting surface cracks of a cast slab according to claim 2, characterized by, The method according to the total surface damage, generating the crack prediction result, comprises the following steps: According to the total surface damage, a crack prediction result is generated by using a cracking criterion formula, and the cracking criterion formula includes: wherein t1 is a start time, t is the sub-deformation time, εcrit is the actual critical strain value, The total surface damage is generated.

4. The method of predicting surface cracks of a cast slab according to claim 1, characterized by, The method according to the obtained test critical strain value and strain influence factor, determining the actual critical strain value, comprises the following steps: According to the test critical strain value and the strain influence factor, an actual critical strain value formula is used to determine the actual critical strain value, and the actual critical strain value formula includes: wherein ε crit is the actual critical strain value, ε crit (tensile test) is the test critical strain value, f grainsize is the grain size factor, fsegregationis the composition segregation factor, f notch is the notch factor.

5. The method of predicting surface cracks of a cast slab according to claim 1, characterized by, The method according to the obtained material properties, machine parameters and process conditions, determining the critical strain rate, comprises the following steps: Based on the material properties, the machine parameters, and the process conditions, a critical strain rate is determined using a critical strain rate formula, the critical strain rate formula comprising: wherein, for the critical strain rate, R is the caster radius of the machine parameter, x is the radial coordinate of the machine parameter, and the origin is at the center of the caster, v c for the casting speed of the process condition, Z is the material property, C is a coefficient, The rate of change of the caster radius R with the material property Z.

6. The method of predicting surface cracks of a cast slab according to claim 1, characterized by, Before the method according to the obtained test critical strain value and strain influence factor, determining the actual critical strain value, further comprises the following steps: According to the existing test data, the area reduction is determined; According to the area reduction, the test critical strain value is determined.

7. The method of predicting surface cracks of a cast slab according to claim 6, characterized by, The method according to the area reduction, determining the test critical strain value, comprises the following steps: According to the area reduction, a test critical strain value formula group is used to determine the test critical strain value, and the test critical strain value formula group includes: wherein RA is the reduction of area, D0 is the diameter of the casting before the test, and D is the diameter of the fracture of the casting before the test. f is the diameter of the fracture of the casting before the test.

8. A device for predicting surface cracks in cast billets, characterized in that, The method comprises the following steps: An actual critical strain value module is configured to determine an actual critical strain value according to an obtained test critical strain value and a strain influence factor, wherein the strain influence factor includes a grain size factor, a composition segregation factor and a notch factor; A critical strain rate module is configured to determine a critical strain rate according to obtained material properties, machine parameters and process conditions; A loss prediction module is configured to generate a crack prediction result using a damage integral method according to the actual critical strain value and the critical strain rate.

9. An electronic device, comprising: The memory is configured to store a computer program; The processor is configured to implement the prediction method of the slab surface crack when the computer program is executed. The storage medium has a computer program stored thereon, and the computer program is configured to implement the prediction method of the slab surface crack when executed by a processor.

10. A computer-readable storage medium, characterized in that, ​

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