A method for processing high-hardness arc plates

Abstract

A method for processing high-hardness circular arc plates comprises the following steps: first, annealing a rough flat steel plate and rolling it into a steel cylinder; welding tool flanges at both ends to obtain a process cylinder; then rough machining and annealing the cylinder to eliminate welding stress; then turning and cutting the cylinder into semi-circular cylinders to release internal stress and obtain a supporting semi-circular cylinder; finally, welding supports at both ends of the supporting semi-circular cylinder; quenching, trimming, and cutting the semi-circular cylinder to obtain a high-hardness circular arc plate; in application, this design improves the surface hardness of the steel coil while fully releasing the internal stress of the steel coil and reasonably controlling deformation. Therefore, the present invention is not only easier to process but also less prone to deformation.

Description

Technical Field

[0001] The invention relates to a processing method, belongs to the field of parts processing, and in particular to a processing method for a high-hardness arc plate. Background Art

[0002] A certain type of ship requires the use of high-hardness arc plates to form runway-like track plates as support. According to product design requirements, the arc plates need to meet the characteristics of thin walls, high precision, and high hardness. At the same time, there are also evenly distributed bolt installation holes around the arc plates, and there are also high requirements for the location of the bolt holes. It is a thin-walled part that is difficult to process.

[0003] An invention application with application number 201310711370.1 and application date December 20, 2013 discloses a method for forming a curled wing. The method mainly includes arc plate forming, curled wing welding forming, tempering treatment and shaping steps. In the welding forming step, the structural forming is completed by using methods such as marked segmented gate pressure, pre-weld reservation and orderly limited welding; in the tempering treatment step, local constraints and vacuum heat treatment methods are used to reduce the quenching deformation of the curled wing and ensure strength requirements.

[0004] Since the part has high hardness requirements, a heat treatment quenching process is required to increase its hardness. The traditional processing method has the following defects: after increasing the surface hardness of the workpiece, the processing process is more difficult, and the workpiece is prone to severe deformation, which does not meet the use requirements.

[0005] The information disclosed in this background technology section is only intended to increase understanding of the overall background of the application and should not be considered as an admission or any form of suggestion that the information constitutes the prior art already known to ordinary technicians in this field. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects and problems of the prior art that high-hardness workpieces are difficult to process and are easily deformed, and to provide a method for processing high-hardness arc plates that is easier to process and less likely to deform.

[0007] To achieve the above objectives, the technical solution of the present invention is: a method for processing a high-hardness arc plate, the method comprising the following steps:

[0008] Step 1: After annealing the rough flat steel plate, roll it into a steel cylinder, and then weld tooling flanges at both ends of the steel cylinder to obtain a process cylinder;

[0009] Step 2: Rough machining the inner and outer arc surfaces of the process cylinder;

[0010] Step 3: Annealing the process cylinder to release internal stress;

[0011] Step 4: Processing threaded holes on the outer arc surface of the process cylinder, and turning the inner arc surface and the outer arc surface of the process cylinder to the prefabricated size;

[0012] Step 5: Cut the process cylinder into half-cylinders along its axis and release the internal stress;

[0013] Step 6: Weld supports between the ends of the semi-tooling flange on the top surface of the semi-annular cylinder and between the ends of the semi-tooling flange on the bottom surface of the semi-annular cylinder to obtain a supported semi-annular cylinder;

[0014] Step 7: quenching the supporting semi-ring cylinder;

[0015] Step 8: Remove the semi-tooling flanges supporting both ends of the semi-ring cylinder to obtain the semi-ring arc plate, and then modify the semi-ring arc plate;

[0016] Step 9: Cut the semi-circular arc plate into the required arc plate size as needed, complete the processing, and obtain a high-hardness arc plate.

[0017] In step 1, the annealing treatment steps are as follows: first, the blank flat steel plate is placed in a heating device with a temperature of 20°C-300°C, then the temperature of the heating device is increased to 790°C-810°C, and kept warm for 3-5 hours, then the temperature of the heating device is reduced to 700°C-720°C, and kept warm for 5-7 hours, and finally the temperature of the heating device is reduced to ≤350°C, and then the blank flat steel plate is taken out to complete the annealing treatment.

[0018] In the step 1, after the steel cylinder is rolled into a steel cylinder, the steel cylinder needs to be corrected and ground to a cylindrical shape without obvious deformation, and then tooling flanges are welded to both ends of the steel cylinder to obtain a process cylinder.

[0019] In the step 2, the rough machining refers to turning the inner and outer arc surfaces of the process cylinder until there are no obvious visible gaps or rust on the surfaces of the inner and outer arc surfaces, and metallic luster is visible.

[0020] In step three, the annealing treatment is as follows: first, the process cylinder is placed in a heating device with a temperature of 20°C-300°C, then the temperature of the heating device is raised to 570°C-590°C, and kept warm for 5-7 hours, and then the temperature of the heating device is lowered to ≤300°C, and the process cylinder is taken out to complete the annealing treatment.

[0021] In the step 4, the prefabricated size means: on the basis of the required arc plate size, retaining the processing allowance of the inner arc surface, outer arc surface and threaded perforation of the process cylinder.

[0022] In the step 5, releasing the internal stress means placing the semi-ring cylinder naturally for 3-5 days.

[0023] In step seven, the quenching treatment step is as follows: first, the supporting semi-ring cylinder is placed in a heating chamber, the heating chamber is vacuumed to ≤0.067 Pa, and then the heating chamber is heated to 850°C-870°C and kept warm for ≥2 hours. After the insulation is completed, the supporting semi-ring cylinder is moved to a quenching chamber for quenching, the quenching oil temperature is 20°C-80°C, and the quenching time is ≥20 minutes. Then, the semi-ring cylinder is taken out to complete the quenching treatment;

[0024] The operation before moving the supporting semi-ring cylinder into the quenching chamber for quenching is: evacuating the quenching chamber to ≤0.067Pa, and filling the quenching chamber with nitrogen until the vacuum degree of the quenching chamber rises to 1×104Pa-5×104Pa and then stopping the nitrogen filling.

[0025] In the step eight, the correction of the semi-circular arc plate refers to: turning and correcting the outer arc surface and the inner arc surface of the semi-circular arc plate to the curvature and thickness required for the formed part.

[0026] In step five and step nine, the cutting method is: wire cutting.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. In a method for processing high-hardness circular arc plates, the present invention first anneals a rough flat steel plate and rolls it into a steel cylinder. Tool flanges are welded to both ends to obtain a process cylinder. This cylinder is then rough-machined and annealed to eliminate welding stress. It is then turned and cut into semi-circular cylinders to release internal stress and obtain a supporting semi-circular cylinder. Finally, supports are welded to both ends of the supporting semi-circular cylinder, which is then quenched, corrected, and cut to obtain a high-hardness circular arc plate. In application, this design improves the surface hardness of the steel coil while fully releasing the internal stress of the steel coil and reasonably controlling deformation. Therefore, the present invention is not only easier to process but also less prone to deformation.

[0029] 2. In a high-hardness circular arc plate processing method of the present invention, the blank flat steel plate is first annealed and then rolled into a steel cylinder to obtain a process cylinder. The purpose of annealing the blank steel plate is to reduce the hardness of the blank steel plate, eliminate the residual stress generated by the blank steel plate during rolling and cooling, and prevent the blank steel plate from cracking during the rolling process, which is beneficial to subsequent processing; then the process cylinder is annealed again after rough processing to eliminate the stress generated during welding. After the front and back annealing treatments are connected, the metal stress before and after the steel plate is greatly eliminated, preventing excessive deformation in subsequent processing. Therefore, the present invention not only has strong front and back annealing connection, but also is easier to process.

[0030] 3. In a method for machining high-hardness circular arc plates, the supporting semi-cylinder is placed in a heating chamber for vacuuming, heating, and insulation, and then quenched. In practice, vacuum quenching isolates the workpiece from air, preventing oxidation that could affect its performance and aesthetics. Therefore, the present invention not only facilitates machining but also meets the desired workpiece requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the process cylinder in the present invention.

[0032] Figure 2 It is a structural schematic diagram of the semi-ring cylinder in the present invention.

[0033] Figure 3 It is a top view of the supporting semi-ring cylinder in the present invention.

[0034] Figure 4 It is a structural schematic diagram of the semi-annular arc plate in the present invention.

[0035] In the figure: process cylinder 1, semi-ring cylinder 2, supporting semi-ring cylinder 3, semi-ring arc plate 4, tooling flange 5, threaded through-hole 6, support 7, semi-tooling flange 8. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] See also Figure 1 — Figure 4 A method for processing a high-hardness arc plate comprises the following steps:

[0038] Step 1: After annealing the rough flat steel plate, roll it into a steel cylinder, and then weld tooling flanges 5 at both ends of the steel cylinder to obtain a process cylinder 1;

[0039] Step 2: Rough machining the inner and outer arc surfaces of the process cylinder 1;

[0040] Step 3: annealing the process cylinder 1 to release internal stress;

[0041] Step 4: Processing threaded holes 6 on the outer arc surface of the process cylinder 1, and turning the inner arc surface and the outer arc surface of the process cylinder 1 to the prefabricated size;

[0042] Step 5: Cut the process cylinder 1 into half-ring cylinders 2 along its axis and release the internal stress;

[0043] Step 6: Weld the supports 7 between the ends of the semi-tooling flange 8 on the top surface of the semi-annular cylinder 2 and between the ends of the semi-tooling flange 8 on the bottom surface of the semi-annular cylinder 2 to obtain a supported semi-annular cylinder 3;

[0044] Step 7: quenching the supporting semi-ring cylinder 3;

[0045] Step 8: Remove the semi-tooling flanges 8 supporting both ends of the semi-annular cylinder 3 to obtain the semi-annular arc plate 4, and then modify the semi-annular arc plate 4;

[0046] Step 9: Cut the semi-annular arc plate 4 into the required arc plate size as needed, complete the processing, and obtain a high-hardness arc plate.

[0047] In step 1, the annealing treatment steps are as follows: first, the blank flat steel plate is placed in a heating device with a temperature of 20°C-300°C, then the temperature of the heating device is increased to 790°C-810°C, and kept warm for 3-5 hours, then the temperature of the heating device is reduced to 700°C-720°C, and kept warm for 5-7 hours, and finally the temperature of the heating device is reduced to ≤350°C, and then the blank flat steel plate is taken out to complete the annealing treatment.

[0048] In the step 1, after the steel cylinder is rolled, it is necessary to correct and grind the steel cylinder to a cylindrical shape without obvious deformation, and then weld tooling flanges 5 at both ends of the steel cylinder to obtain a process cylinder 1.

[0049] In the step 2, the rough machining refers to turning the inner and outer arc surfaces of the process cylinder 1 until the inner and outer arc surfaces have no obvious visible gaps, no obvious rust, and visible metallic luster.

[0050] In step three, the annealing treatment is as follows: first, the process cylinder 1 is placed in a heating device with a temperature of 20°C-300°C, then the temperature of the heating device is raised to 570°C-590°C, and kept warm for 5-7 hours, and then the temperature of the heating device is lowered to ≤300°C, and then the process cylinder 1 is taken out to complete the annealing treatment.

[0051] In the step 4, the prefabricated size means: on the basis of the required arc plate size, retaining the processing allowance of the inner arc surface, outer arc surface and threaded perforation of the process cylinder 1.

[0052] In the step 5, releasing the internal stress means placing the semi-ring cylinder 2 naturally for 3-5 days.

[0053] In the step seven, the quenching treatment step is as follows: first, the supporting semi-ring cylinder 3 is placed in a heating chamber, the heating chamber is evacuated to ≤0.067 Pa, and then the heating chamber is heated to 850°C-870°C and kept warm for ≥2 hours. After the insulation is completed, the supporting semi-ring cylinder 3 is moved to a quenching chamber for quenching, the quenching oil temperature is 20°C-80°C, and the quenching time is ≥20 minutes. Then, the semi-ring cylinder is taken out to complete the quenching treatment;

[0054] The operation before moving the supporting semi-ring cylinder 3 into the quenching chamber for quenching is: evacuating the quenching chamber to ≤0.067Pa, and filling the quenching chamber with nitrogen until the vacuum degree of the quenching chamber rises to 1×104Pa-5×104Pa and then stopping the nitrogen filling.

[0055] In the step eight, the correction of the semi-annular arc plate 4 refers to: turning and correcting the outer arc surface and the inner arc surface of the semi-annular arc plate 4 to the curvature and thickness required for the formed part.

[0056] In step five and step nine, the cutting method is: wire cutting.

[0057] The principle of the present invention is described as follows:

[0058] The high-hardness arc plate is divided into two types: 90° arc segment and 180° arc segment. Both the inner and outer circles of the arc segment need to be processed. The material is high-carbon chromium bearing steel. The wall thickness of the part is 10mm, the maximum outer diameter radius is 439mm, and the hardness requirement is greater than 60HRC for acceptance. Due to the high hardness requirement of the part, a heat treatment quenching process is required to increase the hardness. However, the part after quenching has high stress, which will cause the part to deform and fail to meet the use requirements. At the same time, there are certain difficulties in the processing of high-hardness parts, and suitable methods and means of controlling deformation are required. The processing method provided by the present invention can produce workpieces that meet this requirement.

[0059] Example 1:

[0060] See also Figure 1 — Figure 4 A method for processing a high-hardness arc plate comprises the following steps:

[0061] Step 1: anneal the rough flat steel plate (preferably high carbon chromium alloy steel) and roll it into a steel cylinder. Then, weld tooling flanges 5 at both ends of the steel cylinder to obtain a process cylinder 1.

[0062] Preferably, the annealing treatment comprises the following steps: firstly placing the blank flat steel plate in a heating device at a temperature of 20°C-300°C, then raising the temperature of the heating device to 790°C-810°C and keeping the temperature for 3-5 hours, then lowering the temperature of the heating device to 700°C-720°C and keeping the temperature for 5-7 hours, and finally lowering the temperature of the heating device to ≤350°C, taking out the blank flat steel plate, and completing the annealing treatment;

[0063] Preferably, after the steel cylinder is rolled, it is necessary to correct and grind the steel cylinder to a cylindrical shape without obvious deformation, and then weld tooling flanges 5 at both ends of the steel cylinder to obtain a process cylinder 1;

[0064] Step 2: Rough-process the inner and outer arc surfaces of the process cylinder 1, removing 1mm of allowance;

[0065] Step 3: annealing the process cylinder 1 to release internal stress;

[0066] Preferably, the annealing treatment comprises the following steps: firstly placing the process cylinder 1 in a heating device with a temperature of 20°C to ≤300°C, then raising the temperature of the heating device to 570°C to 590°C and keeping the temperature for 5-7 hours, then lowering the temperature of the heating device to ≤300°C, taking out the process cylinder 1, and completing the annealing treatment;

[0067] Step 4: Process the threaded holes 6 on the outer arc surface of the process cylinder 1 and chamfer it, and turn the inner and outer arc surfaces of the process cylinder 1 to the prefabricated size, leaving a 3mm machining allowance on each side;

[0068] Step 5: Cut the process cylinder 1 into half-ring cylinders 2 along its axis and place it naturally for 3-5 days to release the internal stress (preferably wire cutting).

[0069] Step 6: Weld the supports 7 between the ends of the semi-tooling flange 8 on the top surface of the semi-annular cylinder 2 and between the ends of the semi-tooling flange 8 on the bottom surface of the semi-annular cylinder 2 to obtain the supported semi-annular cylinder 3 (preferably, the material of the supports 7 is consistent with that of the semi-annular cylinder 2);

[0070] Step 7: quenching the supporting semi-ring cylinder 3;

[0071] Step 8: Remove the semi-tooling flanges 8 supporting both ends of the semi-annular cylinder 3 to obtain the semi-annular arc plate 4, and then modify the semi-annular arc plate 4;

[0072] Step nine: Cut the semi-annular arc plate 4 into the required arc plate size as needed, complete the processing, and obtain a high-hardness arc plate (preferably wire cutting).

[0073] Example 2:

[0074] The basic content is the same as Example 1, except that:

[0075] Step 7: quenching the supporting semi-ring cylinder 3;

[0076] Preferably, the quenching treatment step is: first, placing the supporting semi-ring cylinder 3 in a heating chamber, evacuating the heating chamber to ≤0.067 Pa, then heating the heating chamber to 850°C-870°C, and keeping the temperature for ≥2 hours. After the insulation is completed, the supporting semi-ring cylinder 3 is moved to a quenching chamber for quenching, the quenching oil temperature is 20°C-80°C, and the quenching time is ≥20 minutes. Then, the semi-ring cylinder is taken out to complete the quenching treatment;

[0077] The operation before moving the supporting semi-ring cylinder 3 into the quenching chamber for quenching is: evacuating the quenching chamber to ≤0.067Pa, and filling the quenching chamber with nitrogen until the vacuum degree of the quenching chamber rises to 1×104Pa-5×104Pa and then stopping the nitrogen filling.

[0078] Example 3:

[0079] The basic content is the same as Example 1, except that:

[0080] In step seven, after quenching the supporting semi-ring cylinder 3, the inner and outer arc surfaces of the supporting semi-ring cylinder 3 need to be subjected to color flaw detection; if qualified, proceed to step eight; if unqualified, the unqualified parts are repaired by welding; the qualified standard of the color flaw detection is: NB / T 47013.5-2015 Level I.

[0081] Example 4:

[0082] The basic content is the same as Example 1, except that:

[0083] Step 8: Remove the semi-tooling flanges 8 supporting both ends of the semi-annular cylinder 3 to obtain the semi-annular arc plate 4, and then modify the semi-annular arc plate 4 (preferably, use a dedicated CBN turning insert for processing);

[0084] Step 9: Cut the semi-circular arc plate 4 into 90° arc plates and 180° arc plates as required, completing the processing to obtain a high-hardness arc plate.

[0085] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed in the present invention should be included in the protection scope recorded in the claims.

Claims

1. A method for processing a high-hardness arc plate, characterized in that: The method comprises the following steps: Step 1: annealing the rough flat steel plate and rolling it into a steel cylinder, and then welding tooling flanges (5) at both ends of the steel cylinder to obtain a process cylinder (1); the material of the rough flat steel plate is high carbon chromium alloy steel; Step 2: rough machining the inner and outer arc surfaces of the process cylinder (1); Step 3: annealing the process cylinder (1) to release internal stress; Step 4: Processing threaded holes (6) on the outer arc surface of the process cylinder (1), and turning the inner arc surface and the outer arc surface of the process cylinder (1) to the prefabricated size; Step 5: cutting the process cylinder (1) into a semi-circular cylinder (2) along its axis and releasing the internal stress; Step 6: Welding the support (7) between the two ends of the semi-tooling flange (8) on the top surface of the semi-annular cylinder (2) and between the two ends of the semi-tooling flange (8) on the bottom surface of the semi-annular cylinder (2) to obtain a supported semi-annular cylinder (3); Step 7: quenching the supporting semi-ring cylinder (3); Step eight, removing the semi-tooling flanges (8) supporting both ends of the semi-annular cylinder (3) to obtain the semi-annular arc plate (4), and then modifying the semi-annular arc plate (4); Step nine, cutting the semi-annular arc plate (4) into the required arc plate size as required, completing the processing, and obtaining a high-hardness arc plate; the hardness requirement of the high-hardness arc plate is greater than 60HRC; In the step 1, the annealing treatment comprises the following steps: first, placing the blank flat steel plate in a heating device at a temperature of 20° C. to 300° C., then raising the temperature of the heating device to 790° C. to 810° C. and keeping the temperature for 3 to 5 hours, then lowering the temperature of the heating device to 720° C. and keeping the temperature for 5 or 7 hours, and finally lowering the temperature of the heating device to ≤ 350° C., taking out the blank flat steel plate, and completing the annealing treatment; In the step 3, the annealing treatment step is as follows: first, the process cylinder (1) is placed in a heating device with a temperature of 20°C-300°C, then the temperature of the heating device is raised to 570°C-590°C, and kept warm for 5 hours or 7 hours, and then the temperature of the heating device is lowered to ≤300°C, and the process cylinder (1) is taken out to complete the annealing treatment; In the step seven, the quenching treatment step is as follows: first, the supporting semi-ring cylinder (3) is placed in a heating chamber, the heating chamber is evacuated to ≤0.067Pa, and then the heating chamber is heated to 850°C-870°C and kept warm for ≥2 hours. After the heat preservation is completed, the supporting semi-ring cylinder (3) is moved to a quenching chamber for quenching, the quenching oil temperature is 20°C-80°C, and the quenching time is ≥20 minutes before being taken out to complete the quenching treatment.

2. A method for processing a high-hardness arc plate according to claim 1, characterized in that: In the step 1, after the rough flat steel plate is rolled into a steel cylinder, the steel cylinder needs to be corrected and ground to a cylindrical shape without obvious deformation, and then tooling flanges (5) are welded to both ends of the steel cylinder to obtain a process cylinder (1).

3. The method for processing a high-hardness arc plate according to claim 1, characterized in that: In the step 2, the rough machining refers to turning the inner arc surface and the outer arc surface of the process cylinder (1) until the inner arc surface and the outer arc surface have no obvious visible gaps, no obvious rust, and visible metallic luster.

4. The method for processing a high-hardness arc plate according to claim 1, characterized in that: In the step 4, the prefabricated size refers to: on the basis of the required arc plate size, retaining the processing allowance of the inner arc surface, the outer arc surface and the threaded perforation of the process cylinder (1).

5. The method for processing a high-hardness arc plate according to claim 1, characterized in that: In the step 5, releasing the internal stress means placing the semi-ring cylinder (2) naturally for 3-5 days.

6. The method for processing a high-hardness arc plate according to claim 1, characterized in that: The operation before moving the supporting semi-ring cylinder (3) into the quenching chamber for quenching is as follows: evacuating the quenching chamber to a vacuum level of ≤0.067 Pa, and filling the quenching chamber with nitrogen until the vacuum level of the quenching chamber rises to 1×104Pa-5×104Pa, and then stopping the nitrogen filling.

7. The method for processing a high-hardness arc plate according to claim 1, characterized in that: In the step eight, the correction of the semi-annular arc plate (4) refers to turning and correcting the outer arc surface and the inner arc surface of the semi-annular arc plate (4) to the arc and thickness required for the formed part.

8. The method for processing a high-hardness arc plate according to claim 1, characterized in that: In step five and step nine, the cutting method is: wire cutting.

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