Initial blank size simulation optimization method for quenching and subsequent machining of special-shaped metal piece

Abstract

The invention discloses an initial blank size simulation optimization method for quenching and subsequent machining of a special-shaped metal piece. The method comprises the steps that (1) the geometric specification of the special-shaped metal piece is determined; (2) the geometric specification of the intermediate blank is preliminarily designed according to the machining mode and technology and in combination with the simple contour subjected to profiling adjustment; (3) carrying out machining process simulation according to the geometric specification of the designed intermediate blank; (4) evaluation is carried out according to an output result of machining process simulation, and the geometric specification of the quenched intermediate blank is determined; (5) the geometric specification of the initial blank is preliminarily designed in an interference mode according to the scaling coefficient, a quenching scheme is designed according to the actual quenching capacity, and the quenching process is simulated; and (6) evaluation is conducted according to the output result of quenching process simulation, and the geometric specification of the initial blank is determined. The method can effectively reduce interference waste when the size of the initial blank of the special-shaped metal part is selected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of special-shaped metal part processing. Specifically, it is a method for simulating and optimizing the initial blank size of special-shaped metal part quenching and subsequent machining. BACKGROUND

[0002] High-performance and low-density special alloy steel is commonly used in the field of aviation. Related special-shaped metal parts usually need to be machined after blank quenching, but due to the influence of actual quenching process (quenching environment and quenching process) and the distribution of stress field after quenching of special-shaped metal parts, the initial blank is often oversized, causing waste or the risk of deformation and cracking of the special-shaped metal part after machining due to excessive residual stress field. Specifically, most of the special-shaped metal parts used in aviation institutes adopt the largest initial blank size as possible. Considering the high cost of special alloy steel, the actual quenching capacity varies, and it is difficult to define the appropriate initial blank size. In most cases, the initial blank size is oversized, which often causes waste. If the initial blank size of the special-shaped metal part is selected near the critical point, the residual stress after quenching is high, and the defect part is not removed, the service life of the special-shaped metal part after machining is very different in actual use, which is prone to deformation, cracking, stress corrosion and other influences, causing major safety hazards. Therefore, a method for simulating and optimizing the initial blank size of special-shaped metal part quenching and subsequent machining is proposed. SUMMARY

[0003] To this end, the technical problem to be solved by the present application is to provide a method for simulating and optimizing the initial blank size of special-shaped metal part quenching and subsequent machining, which can effectively reduce the interference waste when selecting the initial blank size of the special-shaped metal part, effectively evaluate the rationality of selecting the metal special-shaped part in the blank according to the actual quenching capacity and machining capacity, and prevent the generation of defective parts due to excessive quenching residual stress.

[0004] To solve the above technical problems, the present application provides the following technical solutions:

[0005] A method for simulating and optimizing the initial blank size of special-shaped metal part quenching and subsequent machining, comprising the following steps:

[0006] Step (1), determining the geometric specification of the special-shaped metal part;

[0007] Step (2), designing the geometric specification of the intermediate blank according to the machining method and process and combining the adjusted simple profile;

[0008] Step (3), simulating the machining process according to the designed geometric specification of the intermediate blank;

[0009] Step (4), evaluate the output results of the mechanical processing process simulation, determine the geometric specification of the intermediate blank after quenching;

[0010] Step (5), according to the determined geometric specification of the intermediate blank after quenching, scale the initial blank geometric specification by the preliminary interference design coefficient, and design the quenching scheme according to the actual quenching capacity and then perform the quenching process simulation;

[0011] Step (6), evaluate the output results of the quenching process simulation, evaluate the rationality of the selected position of the intermediate blank in the initial blank after quenching, and determine the geometric specification of the initial blank.

[0012] The manufacturing process of the special-shaped metal part in the aviation field is as shown in Figure 1 The initial blank is quenched to improve or improve the mechanical properties or material properties of the metal blank, and then mechanical processing is performed, including cutting, milling or surface treatment, etc. to obtain a special-shaped metal part meeting the requirements. The present application only simulates and optimizes the initial blank size of the special-shaped metal part suitable for the process.

[0013] The initial blank size simulation optimization method of the special-shaped metal part quenching and subsequent mechanical processing, in step (3), the mechanical processing process simulation output results include stress field and temperature field.

[0014] The initial blank size simulation optimization method of the special-shaped metal part quenching and subsequent mechanical processing, in step (4), the method for evaluating the output results of the mechanical processing process simulation is:

[0015] (4-1) If the designed intermediate blank geometric specification does not meet the requirements, continue to increase the design geometric specification of the intermediate blank, and repeat step (3) to reevaluate;

[0016] (4-2) If the designed intermediate blank geometric specification meets the requirements, continue to evaluate whether the designed intermediate blank geometric specification has optimization space;

[0017] (4-3) If there is optimization space, reduce the design geometric specification of the intermediate blank, and repeat step (3) to reevaluate;

[0018] (4-4) If there is no optimization space, the designed intermediate blank geometric specification is determined as the geometric specification of the intermediate blank after quenching.

[0019] The simulation optimization method for the initial blank size of the special-shaped metal part quenching and subsequent machining, the evaluation standard for the intermediate blank geometry specification meeting the requirements is that after machining, the residual stress value of the special-shaped metal part is less than or equal to 80% of the material yield strength (such as ≤80% σs) or the design threshold; the thermal deformation amount caused by the temperature field in the machining process is within the size tolerance range of the special-shaped metal part; and the size of the intermediate blank can cover all the geometric specifications of the special-shaped metal part, and has sufficient machining allowance (such as ≥5mm) to remove the quenching residual stress layer.

[0020] The simulation optimization method for the initial blank size of the special-shaped metal part quenching and subsequent machining, in step (5), the quenching process simulation output result includes the residual stress field of the initial blank after quenching and the internal and external residual stress difference value.

[0021] The simulation optimization method for the initial blank size of the special-shaped metal part quenching and subsequent machining, in step (6), the method for evaluating the output result of the quenching process simulation is:

[0022] (6-1) If the designed initial blank geometry specification does not meet the requirements, the design method of the initial blank geometry specification is continuously optimized, and step (5) is repeated for re-evaluation;

[0023] (6-2) If the designed initial blank geometry specification meets the requirements, it is continuously evaluated whether there is optimization space for the designed initial blank geometry specification;

[0024] (6-3) If there is optimization space, the design geometry specification of the intermediate blank is reduced, and step (5) is repeated for re-evaluation;

[0025] (6-4) If there is no optimization space, the designed initial blank geometry specification is determined as the geometry specification of the initial blank for the special-shaped metal part quenching and subsequent machining.

[0026] The simulation optimization method for the initial blank size of the special-shaped metal part quenching and subsequent machining, the evaluation standard for the initial blank geometry specification meeting the requirements is that the residual stress field of the initial blank after quenching is uniformly distributed, the residual stress of the edge area (the position where the intermediate blank needs to be cut) is lower than the allowable value (such as ≤150MPa); the internal and external residual stress difference value of the initial blank is lower than the empirical threshold (for reference, the internal and external residual stress field difference value <300MPa in the specific embodiment); the size of the initial blank needs to allow the intermediate blank to be selected in the area with lower residual stress (such as within 5mm inside the outer contour), while avoiding interference waste (such as the scaling factor of the initial blank to the intermediate blank is controlled at 1.1-1.3 times).

[0027] If the simulation evaluation requirements cannot be met, the method attempts to replace the material or improve the quenching capacity.

[0028] In the simulation optimization method of the initial blank size of the special-shaped metal part quenching and subsequent machining, the software used for the machining process simulation and the quenching process simulation is ANSYS software or other commercial software capable of realizing the machining process simulation and the quenching process simulation, the stress change, the residual stress and the thermal deformation in the machining process, the temperature field and the stress field in the machining process, and the machining path and the quenching simulation.

[0029] In step (3) of the simulation optimization method of the initial blank size of the special-shaped metal part quenching and subsequent machining, the output result of the machining process simulation includes the stress field and the temperature field.

[0030] In step (4), the method for evaluating the output result of the machining process simulation is as follows:

[0031] (4-1) If the designed intermediate blank geometric specification does not meet the requirements, the designed intermediate blank geometric specification is continuously increased, and step (3) is repeated to reevaluate;

[0032] (4-2) If the designed intermediate blank geometric specification meets the requirements, it is continuously evaluated whether the designed intermediate blank geometric specification has an optimization space.

[0033] (4-3) If there is an optimization space, the designed intermediate blank geometric specification is reduced, and step (3) is repeated to reevaluate.

[0034] (4-4) If there is no optimization space, the designed intermediate blank geometric specification is determined as the geometric specification of the intermediate blank after quenching.

[0035] The evaluation standard for the intermediate blank geometric specification meeting the requirements is that the residual stress value of the special-shaped metal part after machining is less than or equal to 80% of the material yield strength or a design threshold value, the thermal deformation amount caused by the temperature field in the machining process is within the dimensional tolerance range of the special-shaped metal part, and the size of the intermediate blank can cover all the geometric specifications of the special-shaped metal part and leave a machining allowance greater than or equal to 5 mm.

[0036] In step (5), the output result of the quenching process simulation includes the residual stress field of the initial blank after quenching and the internal and external residual stress difference.

[0037] In step (6), the method for evaluating the output result of the quenching process simulation is as follows:

[0038] (6-1) If the designed initial blank geometry specification does not meet the requirements, continue to optimize the design method of the initial blank geometry specification, repeat step (5) and then evaluate again;

[0039] (6-2) If the designed initial blank geometry specification meets the requirements, continue to evaluate whether there is optimization space for the designed initial blank geometry specification;

[0040] (6-3) If there is optimization space, reduce the design geometry specification of the intermediate blank, and re-evaluate by repeating step (5);

[0041] (6-4) If there is no optimization space, the designed initial blank geometry specification is determined as the initial blank geometry specification for quenching and subsequent machining of the special-shaped metal part;

[0042] The evaluation standard for the initial blank geometry specification meeting the requirements is that the residual stress field distribution of the initial blank after quenching is uniform, the residual stress of the edge region of the intermediate blank to be cut is less than or equal to 150 MPa; the difference between the inner and outer residual stresses of the initial blank is less than or equal to 300 MPa; the size of the initial blank can allow the intermediate blank to be selected in the region within 5 mm from the outer contour, and the scaling factor of the initial blank and the intermediate blank is 1.1-1.3;

[0043] If it is really impossible to meet the simulation evaluation requirements, try to change the material or improve the quenching capacity.

[0044] The technical scheme of the present application achieves the following beneficial technical effects:

[0045] The initial blank size simulation optimization method for quenching and subsequent machining of the special-shaped metal part can effectively reduce the interference waste in the selection of the initial blank size of the special-shaped metal part, effectively evaluate the rationality of the selection of the metal special-shaped part in the blank according to the actual quenching capacity and machining capacity, and prevent the generation of defective parts due to excessive quenching residual stress. The initial blank size simulation optimization method for the special-shaped metal part is suitable for special-shaped metal parts using the manufacturing process of "quenching treatment-machining". BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The manufacturing process schematic diagram of the special-shaped metal part in the present application;

[0047] Figure 2 The initial blank size simulation optimization process schematic diagram of the special-shaped metal part in the embodiment of the present application;

[0048] Figure 3 The schematic diagram of the special-shaped metal part-intermediate blank-initial blank in the embodiment of the present application;

[0049] Figure 4An initial blank quenching simulation stress field distribution schematic diagram in the embodiment of the present application;

[0050] Figure 5 An initial blank quenching simulation internal and external residual stress difference distribution schematic diagram in the embodiment of the present application;

[0051] Figure 6 A middle blank milling simulation stress field distribution schematic diagram in the embodiment of the present application. DETAILED DESCRIPTION

[0052] As shown in the figure, the initial blank size simulation optimization method for the quenching and subsequent machining of the special-shaped metal part in the embodiment includes the following steps: Figure 2

[0053] Step (1), determine the geometric specification of the special-shaped metal part;

[0054] Step (2), preliminarily design the geometric specification of the middle blank according to the machining method and process and combining the adjusted simple profile contour;

[0055] Step (3), perform machining process simulation according to the geometric specification of the designed middle blank; the machining process simulation output result includes stress field and temperature field;

[0056] Step (4), evaluate according to the output result of the machining process simulation to determine the geometric specification of the quenched middle blank; the method for evaluating the output result of the machining process simulation is:

[0057] If the designed geometric specification of the middle blank does not meet the requirements, continue to increase the design geometric specification of the middle blank and repeat step (3) to reevaluate;

[0058] If the designed geometric specification of the middle blank meets the requirements, continue to evaluate whether there is optimization space for the designed geometric specification of the middle blank;

[0059] If there is optimization space, reduce the design geometric specification of the middle blank and repeat step (3) to reevaluate;

[0060] If there is no optimization space, determine the designed geometric specification of the middle blank as the geometric specification of the quenched middle blank;

[0061] The evaluation standard for the geometric specification of the middle blank meeting the requirements is that: after machining, the residual stress value of the special-shaped metal part is less than or equal to 80% of the material yield strength or the design threshold value; the thermal deformation amount caused by the temperature field in the machining process is within the dimensional tolerance range of the special-shaped metal part; and the size of the middle blank can cover all the geometric specifications of the special-shaped metal part and leave a machining allowance greater than or equal to 5mm.

[0062] ​Step (5), according to the determined geometric specification of the intermediate blank after quenching, scaling coefficient is used to preliminarily design the initial blank geometric specification, and the quenching scheme is designed according to the actual quenching capacity, and then the quenching process simulation is carried out; the output results of the quenching process simulation include the residual stress field of the initial blank after quenching and the internal and external residual stress difference value;

[0063] Step (6), according to the output results of the quenching process simulation, the rationality of the selected position of the intermediate blank in the initial blank after quenching is evaluated, and the geometric specification of the initial blank is determined; the method for evaluating the output results of the quenching process simulation is as follows:

[0064] If the designed geometric specification of the initial blank does not meet the requirements, the design method of the geometric specification of the initial blank is continuously optimized, and step (5) is repeated for re-evaluation; if it is really impossible to meet the simulation evaluation requirements, the material is replaced or the quenching capacity is improved;

[0065] If the designed geometric specification of the initial blank meets the requirements, it is continuously evaluated whether there is optimization space for the designed geometric specification of the initial blank;

[0066] If there is optimization space, the designed geometric specification of the intermediate blank is reduced, and step (5) is repeated for re-evaluation;

[0067] If there is no optimization space, the designed geometric specification of the initial blank is determined as the geometric specification of the initial blank for quenching and subsequent machining of the special-shaped metal part;

[0068] The evaluation standard for the initial blank geometric specification meeting the requirements is that the residual stress field distribution of the initial blank after quenching is uniform, the residual stress of the edge region of the intermediate blank to be cut is less than or equal to 150 MPa; the internal and external residual stress difference value of the initial blank is less than or equal to 300 MPa; the size of the initial blank can allow the intermediate blank to be selected in the region within 5 mm inside the outer contour, and the scaling coefficient of the initial blank and the intermediate blank is 1.1-1.3.

[0069] If the selected material really cannot meet the simulation evaluation requirements, the material is replaced or the quenching capacity is improved.

[0070] In the embodiment, the software used for the machining process simulation and the quenching process simulation is ANSYS software, and in other embodiments, other software capable of realizing the machining process simulation and the quenching process simulation can also be used.

[0071] From the simulation results of the quenching process, it can be seen that: Figure 4 It can be seen that: the residual stress field distribution of the initial blank after quenching is uneven, the residual stress of the edge region (such as the outer contour) is high (the maximum value is about 202 MPa), and the residual stress of the internal region is low (the minimum value is about 51 MPa); the edge high stress region needs to be removed through subsequent machining (such as wire cutting).

[0072] By Figure 5 It can be seen that the difference between the initial residual stress inside and outside the blank is larger in the edge area (for example, the maximum value is about 202 MPa), but the overall value meets the empirical threshold (<300 MPa); the intermediate blank is selected in the low-difference area within 5 mm inside the outer contour, so that deformation or cracking caused by excessive stress difference can be avoided.

[0073] By Figure 6 It can be seen that the residual stress of the intermediate blank after milling is mainly concentrated in the surface area (the maximum value is about 237 MPa), and the stress in the internal area is low (tends to 0); the high stress area on the surface needs to be removed through subsequent finishing (such as grinding) to ensure that the stress of the final special-shaped metal part meets the design requirements.

[0074] The distribution of the residual stress field after quenching meets the empirical formula that the difference between the residual stress inside and outside the blank is <300 MPa, and the intermediate blank is made by line cutting at a position within 5 mm inside the outer contour.

[0075] Obviously, the above embodiments are only examples for the purpose of clarity, and are not limiting to the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. It is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the claims of the present patent application.

Claims

1. A method for simulation and optimization of initial blank dimensions for quenching and subsequent machining of a profiled metal piece, characterized in that, The method comprises the following steps: Step (1), determining the geometric specification of the special-shaped metal part; Step (2), preliminarily designing the geometric specification of the intermediate blank according to the machining mode and process and combining the simple profile after profile adjustment; Step (3), performing machining process simulation according to the geometric specification of the designed intermediate blank; Step (4), evaluating according to the output result of the machining process simulation to determine the geometric specification of the intermediate blank after quenching; Step (5), preliminarily designing the geometric specification of the initial blank according to the scaling coefficient of the determined geometric specification of the intermediate blank after quenching, designing a quenching scheme according to the actual quenching capacity and performing quenching process simulation; Step (6), evaluating according to the output result of the quenching process simulation to evaluate the rationality of the position of the intermediate blank after quenching selected in the initial blank and determine the geometric specification of the initial blank.

2. The method for simulation optimization of initial blank dimensions for quenching and subsequent machining of profiled metal parts according to claim 1, characterized in that, In step (3), the output result of the machining process simulation includes a stress field and a temperature field.

3. The method for simulation optimization of initial blank dimensions for quenching and subsequent machining of profiled metal parts according to claim 2, characterized in that, In step (4), the method for evaluating the output result of the machining process simulation is as follows: (4-1) if the designed geometric specification of the intermediate blank does not meet the requirements, the designed geometric specification of the intermediate blank is continuously increased, and step (3) is repeated for re-evaluation; (4-2) if the designed geometric specification of the intermediate blank meets the requirements, it is continuously evaluated whether the designed geometric specification of the intermediate blank has an optimization space; (4-3) if there is an optimization space, the designed geometric specification of the intermediate blank is reduced, and step (3) is repeated for re-evaluation; (4-4) if there is no optimization space, the designed geometric specification of the intermediate blank is determined as the geometric specification of the intermediate blank after quenching.

4. The method for simulation optimization of initial blank dimensions for quenching and subsequent machining of profiled metal parts according to claim 3, characterized in that, The evaluation standard for the geometric specification of the intermediate blank meeting the requirements is that after machining, the residual stress value of the special-shaped metal part is less than or equal to 80% of the yield strength of the material or a design threshold value; the thermal deformation amount caused by the temperature field in the machining process is within the dimensional tolerance range of the special-shaped metal part; and the size of the intermediate blank can cover all the geometric specifications of the special-shaped metal part and has a machining allowance greater than or equal to 5 mm.

5. The method for simulation optimization of initial blank dimensions for quenching and subsequent machining of profiled metal parts according to claim 1, characterized in that, In step (5), the output result of the quenching process simulation includes the residual stress field of the initial blank after quenching and the internal and external residual stress difference value.

6. The method for simulation optimization of initial blank dimensions for quenching and subsequent machining of profiled metal parts according to claim 5, characterized in that, In step (6), the method for evaluating the output result of the quenching process simulation is as follows: (6-1) if the designed geometric specification of the initial blank does not meet the requirements, the design method of the geometric specification of the initial blank is continuously optimized, step (5) is repeated, and then re-evaluation is performed; (6-2) if the designed geometric specification of the initial blank meets the requirements, it is continuously evaluated whether the designed geometric specification of the initial blank has an optimization space; (6-3) if there is an optimization space, the designed geometric specification of the initial blank is reduced, and step (5) is repeated for re-evaluation; (6-4) if there is no optimization space, the designed geometric specification of the initial blank is determined as the geometric specification of the initial blank for quenching and subsequent machining of the special-shaped metal part.

7. The method for simulation optimization of initial blank dimensions for quenching and subsequent machining of profiled metal parts according to claim 6, characterized in that, The evaluation criteria for the initial blank geometry meeting the requirements are: the residual stress field distribution of the initial blank after quenching is uniform, the residual stress of the edge region of the intermediate blank that needs to be cut is less than or equal to 150 MPa; the difference between the inner and outer residual stresses of the initial blank is less than or equal to 300 MPa; the size of the initial blank can allow the intermediate blank to be selected from the region within 5 mm inside the outer contour, and the scaling coefficient of the initial blank to the intermediate blank is between 1.1 and 1.

3.

8. A method of simulation optimization of initial blank dimensions for quenching and subsequent machining of a profiled metal piece according to claim 6, characterized in that, If it is really impossible to meet the simulation evaluation requirements, the material is replaced or the quenching capacity is improved.

9. A method of simulation optimization of initial blank dimensions for quenching and subsequent machining of a profiled metal piece according to claim 1, characterized in that, The software used for the simulation of the machining process and the simulation of the quenching process is ANSYS software.

10. A method of simulation optimization of initial blank dimensions for quenching and subsequent machining of a profiled metal piece according to claim 1, characterized in that, In step (3), the output results of the machining process simulation include stress field and temperature field; In step (4), the method for evaluating the output results of the machining process simulation is: (4-1) If the designed geometry of the intermediate blank does not meet the requirements, continue to increase the design geometry of the intermediate blank and repeat step (3) to re-evaluate; (4-2) If the designed geometry of the intermediate blank meets the requirements, continue to evaluate whether there is optimization space for the designed geometry of the intermediate blank; (4-3) If there is optimization space, reduce the design geometry of the intermediate blank and repeat step (3) to re-evaluate; (4-4) If there is no optimization space, determine the designed geometry of the intermediate blank as the geometry of the intermediate blank after quenching; The evaluation criteria for the intermediate blank geometry meeting the requirements are: after machining, the residual stress value of the special-shaped metal part is less than or equal to 80% of the yield strength of the material or the design threshold; the thermal deformation caused by the temperature field during the machining process is within the dimensional tolerance range of the special-shaped metal part; and the size of the intermediate blank can cover the entire geometry of the special-shaped metal part and leave a machining allowance of more than or equal to 5 mm; In step (5), the output results of the quenching process simulation include the residual stress field of the initial blank after quenching and the difference between the inner and outer residual stresses; In step (6), the method for evaluating the output results of the quenching process simulation is: (6-1) If the designed geometry of the initial blank does not meet the requirements, continue to optimize the design method of the initial blank geometry, repeat step (5) and then evaluate again; (6-2) If the designed geometry of the initial blank meets the requirements, continue to evaluate whether there is optimization space for the designed geometry of the initial blank; (6-3) If there is optimization space, reduce the design geometry of the intermediate blank and repeat step (5) to re-evaluate; (6-4) If there is no optimization space, determine the designed geometry of the initial blank as the geometry of the initial blank for quenching and subsequent machining of the special-shaped metal part; The evaluation criteria for the initial blank geometry meeting the requirements are: the residual stress field distribution of the initial blank after quenching is uniform, the residual stress of the edge region of the intermediate blank that needs to be cut is less than or equal to 150 MPa; the difference between the inner and outer residual stresses of the initial blank is less than or equal to 300 MPa; the size of the initial blank can allow the intermediate blank to be selected from the region within 5 mm inside the outer contour, and the scaling coefficient of the initial blank to the intermediate blank is between 1.1 and 1.3; If this is not possible, then try to change the material or increase the quenching capacity.

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