Hot forming and quenching integrated method for high-strength titanium component based on pressure-displacement-spray quenching intensity flexible regulation and control

Abstract

The invention provides a high-strength titanium component hot forming and quenching integrated method based on pressure-displacement-spray quenching intensity flexible regulation and control, the method comprises four steps of heating and heat preservation treatment, rapid transfer treatment, shape property coordination control treatment and artificial aging treatment, and the shape property coordination control treatment comprises three procedures of rapid pressing, rapid spray cooling and pressure maintaining shape control. According to the method, the technical scheme of speed regulation cooling, mold and component gap adjustment and pulse pressure regulation and pressure maintaining is mainly adopted in the shape property coordination control treatment step, so that the problems of local forming cracking, three-dimensional instability deformation, non-uniform and unstable performance and the like in the existing high-strength titanium component hot forming quenching process are effectively avoided; the high-strength titanium hot forming and quenching integrated treatment disclosed by the invention can be realized by utilizing the existing equipment such as a high-strength steel hot forming press, a manipulator and a heating furnace.

Description

Technical Field

[0001] The present invention belongs to the field of hot forming and quenching processes of metal sheets, and relates to an integrated hot forming and quenching method for metal materials, and particularly to an integrated hot forming and quenching method for high-strength titanium components with flexible regulation of pressure-displacement-spray quenching intensity. Background Art

[0002] With the development of key equipment in key fields in China towards the direction of "lightweight, high mobility, and large-scale", higher requirements are put forward for the core components of key equipment. For example, the core components such as the doors, side panels, and bottom panels of key equipment have undergone a transformation towards "material lightweight, manufacturing integration, and performance refinement" (the "three refinements"). Therefore, it has become one of the key demands for the core components such as the doors, side panels, and bottom panels of key equipment to use lightweight and high-strength titanium alloys to replace the original high-strength steels and apply the advanced integrated hot forming and quenching process technology to replace the existing process of pre-heat treatment and then welding.

[0003] Regarding the integrated hot forming and quenching method, currently, domestic and foreign scholars mainly focus on the research of the integrated hot forming and quenching method for high-strength thin steel sheets (with a thickness of about 2 mm) in the automotive industry, and industrialized mass production has been achieved. At the same time, some scholars have carried out research on the integrated hot forming and quenching method for high-strength aluminum thin sheets (with a thickness < 5 mm), and have developed three integrated hot forming and quenching methods for high-strength aluminum, namely "double cold", "double heat", and "cold-hot", and are gradually promoting industrialization. Currently, some domestic enterprises copy the integrated hot forming and quenching methods for high-strength steel and high-strength aluminum and apply them to the treatment of high-strength titanium components (with a thickness of up to 10 mm). After multiple rounds of "stir-frying" trials, problems such as local cracking during forming, three-dimensional instability deformation, and uneven and unstable performance occur during the trial process, seriously affecting the manufacturing of the core components of key equipment. Therefore, it is urgent to develop an integrated hot forming and quenching method suitable for high-strength titanium. Summary of the Invention

[0004] In view of this, the present invention provides an integrated hot forming and quenching method for high-strength titanium components with flexible regulation of pressure-displacement-spray quenching intensity, realizing the integrated manufacturing of high-strength titanium components, avoiding problems such as cracking during the integrated manufacturing of high-strength titanium components, and the obtained high-strength titanium components have advantages such as precise shape and uniform performance.

[0005] To achieve the above object, the present invention provides a method for integrated hot forming and quenching of high-strength titanium components with flexible control of pressure-displacement-spray quenching intensity. The method includes the following steps: S1: heating and holding treatment, S2: rapid transfer treatment, S3: shape-property coordinated control treatment, and S4: artificial aging treatment; wherein the S3 shape-property coordinated control treatment step includes the following processes: S3-1: rapid pressing, in which the high-strength titanium plate treated in step S2 is rapidly hot-pressed into a high-strength titanium component under the action of a mold; S3-2: rapid spray cooling, in which the high-strength titanium component treated in process S3-1 is rapidly cooled while the gap between the mold and the high-strength titanium component is adjusted under the operation of a spray system with a predetermined medium flow rate and a predetermined pressure; S3-3: pressure holding and shape control, in which the high-strength titanium component treated in process S3-2 is pressure held for a predetermined time in the mold in a pulsed cycle pressure application manner; wherein the minimum thickness of the high-strength titanium plate and the high-strength titanium component is 8 mm, and the maximum thickness is 16 mm.

[0006] In some possible embodiments, the material of the high-strength titanium plate is selected from commercially available titanium alloy plates such as TC4, TC11, TC21, TB8, TA15, TA32, etc.

[0007] In some possible embodiments, in step S1, the high-strength titanium plate is placed in a first heating furnace at a temperature of 700-900 °C, heated and held for t1 time; wherein, when the thickness of the high-strength titanium plate < 10 mm, t1 is 20-35 minutes, and when the thickness of the high-strength titanium plate ≥ 10 mm, t1 is 40-80 minutes. Thus, by further differentiating the thickness of the high-strength titanium plate for heating, an ideal hot forming and quenching effect of the high-strength titanium component can be obtained more reliably.

[0008] In some possible embodiments, in step S2, the high-strength titanium plate treated in step S1 is rapidly transferred onto the female mold of the mold. Wherein, when the thickness of the high-strength titanium plate < 12 mm, the transfer time t2 is 8-12 seconds, and when the thickness of the high-strength titanium plate ≥ 12 mm, t2 is 12-16 seconds. Thus, by further differentiating the thickness of the high-strength titanium plate for transfer, an ideal hot forming and quenching effect of the high-strength titanium component can be obtained more reliably.

[0009] In some possible embodiments, in the S3-1 process, the rapid hot pressing forming time t3 ≤ 10 seconds. Among them, when the thickness of the high-strength titanium plate < 10 mm, t3 is 2 - 6 seconds; when the thickness of the high-strength titanium plate ≥ 10 mm, t3 is 6 - 10 seconds; and when the thickness of the high-strength titanium plate < 12 mm, the rapid hot pressing forming pressure is 10 - 12 MPa, when the thickness of the high-strength titanium plate ≥ 12 mm, the rapid hot pressing forming pressure is 12 - 20 MPa. Thus, by further differentiating the thickness of the high-strength titanium plate for hot pressing forming, an ideal hot forming quenching effect of the high-strength titanium component can be obtained more reliably.

[0010] In some possible embodiments, the spray system is arranged on the male mold of the mold. In some possible embodiments, the spray system is arranged on both the male mold and the female mold of the mold.

[0011] In some possible embodiments, in the S3-2 process, it includes two-stage cooling; the medium injection pressure for the first-stage cooling is 1.0 - 1.5 MPa, and the medium injection pressure for the second-stage cooling is 0.5 - 1.0 MPa; and when the thickness of the high-strength titanium plate < 10 mm, the first-stage cooling time t4 is 6 - 10 seconds, when the thickness of the high-strength titanium plate ≥ 10 mm, t4 is 10 - 20 seconds. Thus, by adjusting the spray quenching intensity during the cooling process, controlling the cooling rate of the high-strength titanium component, and reducing the internal stress in the high-strength titanium component during the hot forming process, defects such as quenching deformation and cracking generated in the high-strength titanium component during the cooling process can be effectively avoided; in addition, by further differentiating the thickness of the high-strength titanium plate for spray cooling, an ideal hot forming quenching effect of the high-strength titanium component can be obtained more reliably.

[0012] In some possible embodiments, in the S3-2 process, when cooled to time t5, the male mold of the mold is displaced upward so that it is separated from the high-strength titanium component. After maintaining the separation time t6, the male mold of the mold is displaced downward so that it contacts the high-strength titanium component and applies pressure, where t4 = t5, and t6 is 2 - 6 seconds. Thus, by adjusting the gap between the mold and the high-strength titanium component during the rapid spray cooling process, the male mold of the mold is separated from the high-strength titanium component, eliminating the rigid constraint between the mold and the high-strength titanium component, so that structural defects generated in the high-strength titanium component due to the rigid constraint of the mold during the cooling process can be effectively avoided.

[0013] In some possible embodiments, in the process of S3-3, the peak pressure of holding pressure is 6 MPa, the valley pressure of holding pressure is 2 MPa, the cycle time is 30 minutes, and the total holding time ≥ 240 minutes. By further defining each parameter of the periodic fluctuating pressure application, the peak elimination and equalization of internal stress during the forming process of high-strength titanium components are realized, the instantaneous stress pressure and the final internal stress of the high-strength titanium components are reduced, and the deformation caused by excessive internal stress in the high-strength titanium components treated by S3-2 is prevented, and the ideal hot forming and quenching effect of the high-strength titanium components can be obtained more reliably.

[0014] In some possible embodiments, in the step S4, the high-strength titanium component treated in the step S3 is put into a second heating furnace with a temperature of 400-600 °C, heated and kept warm for a time t7, and t7 is 600-1200 minutes. Thus, by further defining each parameter of the artificial aging treatment, the ideal hot forming and quenching effect of the high-strength titanium component can be obtained more reliably.

[0015] In some possible embodiments, before performing the step S1, the high-strength titanium plate is in a rolled state or a rolled + annealed state.

[0016] The present invention mainly adopts the technical solutions of speed control cooling, adjusting the gap between the mold and the component, and pulse pressure regulation and holding pressure in the shape and property co-control treatment step, effectively avoiding problems such as local cracking during forming, three-dimensional instability deformation, uneven and unstable performance in the existing hot forming and quenching process of high-strength titanium components, and the integrated treatment of high-strength titanium hot forming and quenching of the present invention application can be realized by using existing equipment such as high-strength steel hot forming presses, manipulators, and heating furnaces.

[0017] The technical solution of the present invention will be further described below with reference to the drawings. Description of the Drawings

[0018] Figure 1 It is a tissue photo taken of a high-strength titanium component manufactured by the method according to Embodiment 1 of the present invention using an optical microscope;

[0019] Figure 2 It is a crack photo of a high-strength titanium component manufactured by the method according to Comparative Example 1. Detailed Embodiments

[0020] To make this application easier to understand, the following further elaborates on this application in combination with specific embodiments. Unless otherwise specified, the experimental methods described in this application are all conventional methods; unless otherwise specified, the materials can be obtained from commercial channels. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. In case of inconsistency, the meaning described in this specification or the meaning derived from the content recorded in this specification shall prevail. Additionally, the terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0021] For the purpose of accurately describing the technical content in this application and for accurately understanding this application, the following explanations or definitions are given for the words and terms used in this specification before describing the specific embodiments.

[0022] In the term "pressure - displacement - spray quenching intensity" of this invention application, the "pressure" means the pressure applied to the mold by the hot - forming press, and further applied by the mold to the high - strength titanium component.

[0023] In the term "pressure - displacement - spray quenching intensity" of this invention application, the "displacement" means the displacement formed by adjusting the distance between the male mold of the mold, the high - strength titanium component, and the female mold by the hot - forming press.

[0024] In the term "pressure - displacement - spray quenching intensity" of this invention application, the "spray quenching intensity" means adjusting the cooling capacity of the high - strength titanium component by regulating the water flow rate and pressure of the spray quenching system of the mold.

[0025] To facilitate the implementation of the technical solutions in this invention application, the following describes exemplary embodiments.

[0026] Example 1:

[0027] Manufacture a high - strength titanium component using the pressure - displacement - spray quenching intensity flexible regulation high - strength titanium component hot - forming and quenching integration method of this embodiment. The specific steps are as follows:

[0028] S1: Heating and heat - preservation treatment. Place a high - strength titanium plate with a thickness of 12 mm into a first heating furnace heated to 850 °C, heat and keep it warm for 60 minutes.

[0029] S2: Rapid transfer treatment. Use a manipulator to place the high - strength titanium plate that has completed the heating and heat - preservation treatment in S1 on the female mold of the mold with a spray system. The transfer time is 12 seconds.

[0030] S3: Shape - property coordinated control treatment. Perform the following three process treatments on the high - strength titanium component in sequence:

[0031] S3-1: Quick Compression Molding: The male mold with a spraying system moves under the action of a hot forming press and fits with the above-mentioned female mold to form the shape of a high-strength titanium component, where the forming time is 7 seconds and the forming pressure is 12 MPa;

[0032] S3-2: Ultra-fast Spray Cooling: Quickly start the spraying systems of the male and female molds of the mold, and spray water to cool the high-strength titanium component that has completed the S3-1 rapid forming. The spraying pressure is 1.2 MPa between 0 and 10 seconds, and 0.6 MPa between 10 and 240 seconds; during this process, when the spraying cooling lasts for 10 seconds, the male mold of the mold moves upward 3 mm under the action of the hot forming press. At this time, the male mold of the mold is significantly separated from the high-strength titanium component for 2 seconds. Subsequently, the male mold of the mold is lowered, brought into contact with the high-strength titanium component and pressure is applied.

[0033] S3-3: Pressure Holding and Shape Control: Subsequently, adjust the pressure holding pressure to 4 MPa and hold the pressure for 30 minutes. Then adjust the pressure holding pressure to 2.5 MPa and hold the pressure for 30 minutes. Then adjust the pressure holding pressure to 4 MPa and hold the pressure for 30 minutes. Repeat this process until the pressure holding and shape control time reaches 300 minutes.

[0034] S4: Artificial Aging Treatment. Put the high-strength titanium component that has completed the S3 treatment into a second heating furnace that has been heated to 450 °C, heat and keep it warm for 720 minutes.

[0035] The production results show that there are no cracks on the surface of the high-strength titanium component processed by the technical solution of the present invention. The microstructure was observed using an optical microscope, as Figure 1 shown. The microstructure is very uniform and fine. According to the national standard (GB / T 228.1-2020 Metallic materials - Tensile testing - Part 1: Method of test at room temperature), the conventional mechanical properties of the high-strength titanium component were measured. The tensile strength is (1120 ± 8) MPa and the elongation is (12.0 ± 0.5)%.

[0036] Comparative Example 1:

[0037] In this comparative example, the "hot forming and quenching integration method for high-strength steel and high-strength aluminum" described in the background technology was used to manufacture high-strength titanium components. The specific steps are as follows:

[0038] S101: Heating and Insulation Treatment. Put a high-strength titanium plate with a thickness of 12 mm into a first heating furnace that has been heated to 850 °C, heat and keep it warm for 60 minutes.

[0039] S201: Quick Transfer Treatment. Use a manipulator to place the high-strength titanium plate that has completed the S1 heating and insulation treatment on the female mold of the mold with a spraying system. The transfer time is 12 seconds.

[0040] S301: Forming and quenching treatment. The male die of the mold quickly contacts and holds pressure with the female die of the mold under the action of a hot forming press, where the forming pressure is 10 MPa and the pressure holding time is 300 minutes.

[0041] S401: Artificial aging treatment. The high-strength titanium component after completing S3 treatment is placed in a second heating furnace heated to 450 °C, heated and held for 720 minutes.

[0042] The production results are as Figure 2 shown. After the high-strength titanium component undergoes S3 forming and quenching treatment, obvious cracks appear on its surface.

[0043] By comparing the production results of Example 1 and Comparative Example 1, it can be seen that the method for integrally forming and quenching high-strength titanium components with flexible regulation of pressure-displacement-spray quenching intensity according to the present invention can effectively avoid problems such as local cracking during forming, three-dimensional instability deformation, and uneven and unstable properties existing in the existing integral forming process of high-strength titanium components. The obtained high-strength titanium component has a very uniform and fine structure and good mechanical properties.

[0044] The above is only the preferred embodiment of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments. Without departing from the concept of the present application, more other equivalent embodiments can also be included, all of which belong to the protection scope of the present application.

Claims

1. A method for hot forming and quenching of high-strength titanium components based on flexible control of pressure-displacement-quenching intensity, characterized in that: The following steps are involved: S1: heating and heat preservation treatment, S2: rapid transfer treatment, S3: shape coordination treatment and S4: artificial aging treatment; The S3 shape coordination processing step includes the following steps: S3-1: rapid pressing, wherein the high-strength titanium plate processed in step S2 is rapidly hot-pressed into a high-strength titanium component under the action of a mold; S3-2: Rapid spray cooling, wherein the high-strength titanium component processed by step S3-1 is rapidly cooled in a spray system operating at a predetermined medium flow rate and a predetermined pressure, while adjusting the gap between the mold and the high-strength titanium component; S3-3: pressure-maintaining and shape-controlling, wherein the high-strength titanium component processed by step S3-2 is maintained under pressure in the mold for a predetermined time in a pulse cycle; The minimum thickness of the high-strength titanium plate and the high-strength titanium component is 8 mm, and the maximum thickness is 16 mm.

2. The method according to claim 1, characterized in that In the step S1, the high-strength titanium plate is placed in a first heating furnace at a temperature of 700-900° C., and heated and kept warm for a time of t1; Wherein, when the thickness of the high-strength titanium plate is less than 10 mm, t1 is 20 to 35 minutes. When the thickness of the high-strength titanium plate is ≥10 mm, t1 is 40 to 80 minutes.

3. The method according to claim 1, characterized in that: In the step S2, the high-strength titanium plate processed in the step S1 is quickly transferred to the female mold of the mold, wherein: When the thickness of the high-strength titanium plate is less than 12 mm, the transfer time t2 is 8 to 12 seconds. When the thickness of the high-strength titanium plate is ≥12 mm, t2 is 12 to 16 seconds.

4. The method according to claim 1, characterized in that In the S3-1 process, the rapid hot pressing forming time t3 is ≤ 10 seconds. Wherein, when the thickness of the high-strength titanium plate is less than 10 mm, t3 is 2 to 6 seconds. When the thickness of the high-strength titanium plate is ≥10 mm, t3 is 6 to 10 seconds; and When the thickness of the high-strength titanium plate is less than 12 mm, the rapid hot pressing forming pressure is 10-12 MPa. When the thickness of the high-strength titanium plate is ≥12 mm, the rapid hot pressing pressure is 12-20 MPa.

5. The method according to claim 1, characterized in that In the S3-2 process, two stages of cooling are included; the medium injection pressure of the first stage of cooling is 1.0-1.5 MPa, and the medium injection pressure of the second stage of cooling is 0.5-1.0 MPa; and when the thickness of the high-strength titanium plate is less than 10 mm, the first stage cooling time t4 is 6-10 seconds, and when the thickness of the high-strength titanium plate is ≥10 mm, t4 is 10-20 seconds.

6. The method according to claim 1 or 5, characterized in that: In the S3-2 process, when cooling to time t5, the male mold of the mold is displaced upward so that it is separated from the high-strength titanium component. After maintaining the separation time t6, the male mold of the mold is displaced downward so that it contacts the high-strength titanium component and applies pressure, wherein t4=t5, and t6 is 2 to 6 seconds.

7. The method according to claim 1, characterized in that In the S3-3 process, the peak holding pressure is 6 MPa, the valley holding pressure is 2 MPa, the cycle time is 30 minutes, and the total holding time is ≥240 minutes.

8. The method according to claim 1, characterized in that In the step S4, the high-strength titanium component processed in the step S3 is placed in a second heating furnace at a temperature of 400-600°C and heated for a time of t7, where t7 is 600-1200 minutes.

9. The method according to claim 1, characterized in that: Before performing the step S1, the high-strength titanium plate is in a rolled state or a rolled + annealed state.

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