A method of additive manufacturing of a seamless tube piercing roll

Abstract

The application discloses a kind of seamless steel tube piercing roller's additive manufacturing method, it is applied to seamless steel tube piercing roller, seamless steel tube piercing roller includes the entrance cone and exit cone being connected along its axial direction;The additive manufacturing method includes the following steps: the whole turning of the roll surface of seamless steel tube piercing roller;Several long slots are opened in the multilayer cladding area on the roll surface and distributed along the circumferential direction, there is interval between each long slot, the length direction of long slot is consistent with the length direction of seamless steel tube piercing roller;Wherein multilayer cladding area is the roll surface of entrance cone and the roll surface of the first section of exit cone connected with entrance cone;The remaining part of exit cone is single-layer cladding area;The roll surface of seamless steel tube piercing roller is preheated;At least one laser cladding is carried out in multilayer cladding area, after each laser cladding, the long slot is repaired;The roll surface is overall covered with a layer of laser cladding, and after the laser cladding, the long slot is repaired;Slowly cool.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a roller, and more particularly to a method for manufacturing a perforated roller. Background Technology

[0002] Seamless steel pipe is a widely used and economical steel material. In the production process of seamless steel pipe, especially in the production process of high alloy steel, the wear of the piercing roller surface is very serious. This not only affects the surface quality of the pipe, but also reduces its service life, increases the roller replacement time, and seriously affects the production capacity of high alloy steel.

[0003] Laser cladding can be used to modify the surface of perforated rollers by cladding materials containing different active elements onto the surface of the perforated roller substrate, thus preparing a coating with excellent wear resistance, corrosion resistance, fatigue resistance, and oxidation resistance that is metallurgically bonded to the substrate.

[0004] However, due to the complex rolling process and deformation stress during piercing, the middle position of the inlet cone experiences the greatest stress and the deepest wear, while the wear on the outlet cone is very small, and the degree of wear varies at different positions. Furthermore, to increase friction and ensure proper engagement, the inlet cone is grooved. Laser cladding repair piercing rolls still encounter numerous problems during use, such as insufficient single-layer cladding thickness on the inlet cone leading to excessively rapid wear; pits appearing within 50mm of the highest point on the roll surface posing a quality risk; and excessively rapid wear at the grooved area after cladding causing cracks on the tube surface.

[0005] Chinese patent document CN110396689A, published on November 1, 2019, entitled "A Method for Preparing a Laser Cladding Strengthened Centrifugal Roller," discloses the following steps: S1, Pre-treatment of the centrifugal roll: The processed centrifugal roll is machined along the working roll surface and the machined surface is cleaned to remove oxide scale, impurities, and oil stains; S2, Preparation of alloy powder resistant to high temperature wear and magma erosion; S3, The centrifugal roll is mounted on a processing machine tool with a high-power semiconductor laser, and the alloy powder is synchronously delivered through laser scanning, and the alloy powder is used to perform surface laser cladding on the working roll surface of the centrifugal roll; S4, Colorimetric testing of the laser cladding layer is performed, followed by grinding; S5, The laser cladding strengthened centrifugal roll is packaged for use. The service life of the strengthened centrifugal roll prepared by this method is more than three times that of the traditional welded stainless steel centrifugal roll. However, this method still cannot adapt to the special working conditions of seamless steel pipe piercing and cannot be applied to the surface cladding of pierced rolls. Summary of the Invention

[0006] The purpose of this invention is to provide an additive manufacturing method for a seamless steel pipe piercing roller, which can improve the wear resistance of the piercing roller, reduce the wear rate of the piercing roller, reduce the total roller change time, and increase the single-cycle production capacity.

[0007] To achieve the above objectives, the present invention proposes an additive manufacturing method for a seamless steel pipe piercing roll, which is applied to the seamless steel pipe piercing roll, the seamless steel pipe piercing roll including an inlet cone and an outlet cone connected along its axial direction; the additive manufacturing method includes the following steps:

[0008] The surface of the seamless steel pipe piercing roll is machined as a whole;

[0009] Several elongated grooves distributed along the circumference are opened in the multi-layer cladding area on the roller surface, with intervals between each elongated groove. The length direction of the elongated grooves is consistent with the length direction of the seamless steel pipe piercing roller. The multi-layer cladding area is the roller surface of the inlet cone and the roller surface of the first section of the outlet cone connected to the inlet cone. The remaining part of the outlet cone is a single-layer cladding area.

[0010] Preheat the roller surface of the seamless steel pipe piercing roller;

[0011] At least one laser cladding is performed in the multi-layer cladding area, and the elongated groove is repaired after each laser cladding.

[0012] A layer of laser cladding is applied to the entire roller surface, and the elongated groove is repaired after the laser cladding is applied.

[0013] Cool slowly.

[0014] Furthermore, in the additive manufacturing method for seamless steel pipe piercing rolls described in this invention, the overall turning of the roll surface of the seamless steel pipe piercing roll specifically includes: determining the turning depth based on the set number of cladding layers, the maximum wear depth of the piercing roll surface, and the thickness of a single cladding layer, so as to perform overall turning of the roll surface of the piercing roll.

[0015] Furthermore, in the additive manufacturing method for seamless steel pipe perforated rolls described in this invention, the turning depth S 改车 for:

[0016] S 改车 = (K-1)×S 单层 +S 最深 +2~6;

[0017] Where K represents the set number of cladding layers, S 单层 Indicates the thickness of a single cladding layer; S 最深 This indicates the maximum wear depth of the perforated roll surface as measured, where the unit parameters for single-layer cladding thickness, maximum wear depth of the perforated roll surface, and turning depth are all in mm.

[0018] Furthermore, in the additive manufacturing method for the seamless steel pipe piercing roller described in this invention, the multi-layer cladding region includes multiple sub-regions with different numbers of cladding layers arranged along the axial direction of the seamless steel pipe piercing roller, wherein the number of cladding layers in each sub-region decreases along the direction from the inlet cone end face to the outlet cone end face.

[0019] That is, in some embodiments of the present invention, the multi-layer cladding area can be further divided into multiple sub-regions, and these sub-regions have different numbers of cladding layers.

[0020] In some implementations, the number of cladding layers in each sub-region decreases along the direction from the inlet cone end face to the outlet cone end face. For example, the multi-layer cladding region is divided into three sub-regions, and the number of cladding layers in the three sub-regions can be 5, 4, 3, or 4, 3, 2, respectively.

[0021] In other embodiments, the same number of cladding layers, such as 3 or 2 layers, are applied to all multi-layer cladding areas.

[0022] Furthermore, in the additive manufacturing method for the seamless steel pipe perforated roller described in this invention, the first section of the outlet cone is a region extending 50mm from the high point toward the end face of the outlet cone, and the high point is the position where the outlet cone and the inlet cone connect.

[0023] Furthermore, in the additive manufacturing method for the seamless steel pipe piercing roll described in this invention, after the overall turning step of the seamless steel pipe piercing roll surface and before the step of opening several elongated grooves distributed along the circumferential direction in the multi-layer cladding area on the roll surface, the method further includes the following step:

[0024] A 30-60° chamfer is machined at the junction of the multi-layer cladding area and the single-layer cladding area.

[0025] This procedure can prevent stress concentration.

[0026] Furthermore, in the additive manufacturing method for the seamless steel pipe perforated roller described in this invention, the starting position of the elongated groove in the length direction is 100-300mm away from the end face of the inlet cone.

[0027] Furthermore, in the additive manufacturing method for the seamless steel pipe perforated roller described in this invention, the length of the elongated groove is 200-400mm, the width is 15-30mm, and the depth is 0.3-2mm.

[0028] Creating elongated grooves on the roller surface can increase the friction between the perforated roller and the metal being processed.

[0029] Furthermore, in the additive manufacturing method for the seamless steel pipe perforated roller described in this invention, a chamfer of 30-60° is machined on the edge of the elongated groove.

[0030] This procedure helps avoid insufficient powder thickness and stress concentration during laser cladding.

[0031] Furthermore, in the additive manufacturing method of the seamless steel pipe piercing roll described in this invention, in the step of preheating the roll surface of the seamless steel pipe piercing roll, the overall temperature of the roll surface is controlled to be ≥150℃, and the temperature of the cladding zone is 300~350℃.

[0032] Furthermore, in the additive manufacturing method for the seamless steel pipe perforated roller described in this invention, the alloy powder used for laser cladding is nickel-based alloy powder or cobalt-based alloy powder.

[0033] Furthermore, in the additive manufacturing method for seamless steel pipe perforated rollers described in this invention, the laser cladding power can be 2700-3200W, the spot diameter φ3-4mm, the scanning speed can be 1800-2500mm / min, the overlap can be 0.6-1mm, the powder output can be 18-28g / min, and the thickness of each cladding layer can be 0.8-1.5mm.

[0034] The additive manufacturing method for seamless steel pipe piercing rolls described in this invention has the following advantages and

[0035] Beneficial effects:

[0036] The present invention sets different cladding layer thicknesses according to the different wear degrees of the inlet cone and outlet cone of the perforated roller. The inlet cone and part of the outlet cone after the high point of the perforated roller are clad with multiple layers, while the remaining part of the outlet cone is clad with one layer, which is conducive to achieving the technical effect in a high-efficiency and low-cost manner.

[0037] The present invention adopts a process of first opening a long groove and then cladding it, and then determining the position of the long groove after cladding before processing. This ensures that the groove position and other positions on the roller surface have the same thickness, and avoids the large difference in wear depth caused by uneven cladding thickness, which would result in defects on the surface of the steel pipe.

[0038] In a preferred embodiment of the present invention, a formula for the thickness of old roll turning is proposed based on the thickness of the laser cladding layer and the deepest wear depth. This formula can be used to conveniently determine the thickness of the roll surface modification.

[0039] In a preferred embodiment of the present invention, in order to avoid cladding quality defects and stress concentration at the junction of multi-layer and single-layer cladding and at the edge of the groove, chamfering is performed to facilitate powder falling and cladding. Attached Figure Description

[0040] Figure 1 The flowchart illustrates the steps of one embodiment of the additive manufacturing method for seamless steel pipe perforated rollers according to the present invention.

[0041] Figure 2The diagram schematically illustrates multi-layer and single-layer cladding areas on a seamless steel pipe piercing roll in one embodiment. Detailed Implementation

[0042] The additive manufacturing method for seamless steel pipe perforated rollers of the present invention will be further explained and described below with reference to specific embodiments and accompanying drawings. However, this explanation and description do not constitute an improper limitation on the technical solution of the present invention.

[0043] Figure 1 The flowchart illustrates the steps of one embodiment of the additive manufacturing method for seamless steel pipe perforated rollers according to the present invention.

[0044] like Figure 1 As shown, in one embodiment, the additive manufacturing method for a seamless steel pipe piercing roll includes the steps of:

[0045] S1: Determine the geometric structure of the laser cladding layer, that is, determine the multi-layer cladding area and single-layer cladding area on the perforated roller, as well as the number of cladding layers in each cladding area.

[0046] Figure 2 The diagram schematically illustrates multi-layer and single-layer cladding areas on a seamless steel pipe piercing roll in one embodiment.

[0047] from Figure 2 As can be seen, the seamless steel pipe piercing roll has an inlet cone and an outlet cone connected along its axial direction, and the slopes of these two parts are different. The connection point between the inlet cone and the outlet cone is the high point 3. In this invention, the roll surface of the seamless steel pipe piercing roll is divided into a multi-layer cladding region 1 and a multi-layer cladding region 2, wherein the multi-layer cladding region includes the roll surface of the inlet cone and the roll surface of the first section of the outlet cone connected to the inlet cone, and the remaining part of the outlet cone is a single-layer cladding region.

[0048] exist Figure 2 In the embodiments shown, the inlet cone and the distance m after the high point 3 are all multi-layer cladding areas. In some embodiments, m can be 50 mm.

[0049] In a specific example, the number of cladding layers in a multi-layer cladding area can be two.

[0050] Of course, in other embodiments, the multi-layer cladding region can also be divided into multiple sub-regions with different numbers of cladding layers arranged along the axial direction of the seamless steel pipe piercing roller, wherein the number of cladding layers in each sub-region decreases along the direction from the inlet cone end face to the outlet cone end face. For example, the multi-layer cladding region is divided into three sub-regions, and the number of cladding layers in the three sub-regions can be 5, 4, 3, or 4, 3, 2, respectively.

[0051] S2: Inspect and machine the surface of the seamless steel pipe piercing roll. In some embodiments, step S2 may specifically include:

[0052] S21: Determine the turning depth based on the set number of cladding layers, the maximum wear depth of the perforated roll surface, and the thickness of a single cladding layer, so as to perform overall turning on the surface of the perforated roll.

[0053] In some implementations, the depth of cut S can be determined based on the following formula. 改车 :

[0054] S 改车 = (K-1)×S 单层 +S 最深 +2~6;

[0055] Where K represents the set number of cladding layers, S 单层 Indicates the thickness of a single cladding layer; S 最深 This indicates the maximum wear depth of the perforated roll surface as measured, where the unit parameters for single-layer cladding thickness, maximum wear depth of the perforated roll surface, and turning depth are all in mm.

[0056] For example, in a specific instance, the measured maximum wear depth of the perforated roller surface was 9mm, and the set single-layer cladding thickness for laser cladding was 1.1mm, according to the formula S 改车 = (K-1)×S 单层 +S 最深 +2~6, when the number of cladding layers in the multi-layer cladding region is set to 2, the turning depth S of the multi-layer cladding region can be obtained by substituting the parameters. 1改车 The depth of machining in the single-layer cladding zone is: (2-1)*1.1+9+5=15.1mm; 2改车 The result is: (1-1)*1.1+9+5=14mm.

[0057] S22: A 45° chamfer is applied at the junction of multi-layer and single-layer laser cladding to avoid stress concentration.

[0058] S23: Several elongated grooves distributed along the circumference are opened in the multi-layer cladding area on the roller surface. There is a gap between each elongated groove. The length direction of the elongated groove is consistent with the length direction of the seamless steel pipe piercing roller.

[0059] In a specific example, an elongated groove is cut at a position 200mm from the inlet cone of the roller surface towards the outlet cone. The groove is 210mm long, 20mm wide, and 0.5mm deep. Preferably, the edges of the groove are chamfered at 45° to avoid insufficient powder thickness and stress concentration during laser cladding.

[0060] S24: Use a measuring tool caliper to check the roll shape after the roll surface is machined.

[0061] S25: Use magnetic particle inspection to ensure that the roller surface is free of defects such as cracks, pits and rust residue.

[0062] S3: Perforated roller clamping and cleaning, cleaning away magnetic powder and grease stains from the roller surface.

[0063] S4: Roller surface preheating ensures an overall roller surface temperature ≥150℃ and a cladding zone temperature of 320℃. Nickel-based alloy powder is used and dried. In some embodiments, the preheating energy source can be liquefied petroleum gas or a high-frequency electromagnetic induction coil.

[0064] S5: Laser cladding for the base layer; perform at least one laser cladding in the designated multi-layer cladding area; after each cladding is completed, use a ruler to measure the position of the elongated groove.

[0065] In some implementations, the specific method for measuring the position of the elongated groove using a ruler can be as follows: Place the ruler flat on the elongated groove after cladding, with the junction of the light-transmitting and opaque areas indicating the groove edge, and mark the edge position. Connect the marks with a line, with the area inside the coil indicating the position of the elongated groove, and then grind the elongated groove as required.

[0066] S6: Laser cladding of the cover surface, which clads the entire roller surface with a layer, and then repairs the long groove again.

[0067] It should be noted that, in some embodiments, the parameters of each laser cladding can be controlled as follows: laser cladding power can be 2700-3200W, spot diameter φ3-4mm, scanning speed can be 1800-2500mm / min, overlap can be 0.6-1mm, powder output can be 18-28g / min, and the thickness of each cladding layer can be 0.8-1.5mm.

[0068] In a more specific example, the laser cladding power can be set to 2900W, spot diameter φ3.5mm, scanning speed 2000mm / min, overlap 0.8mm, powder output 22g / min, and cladding thickness of 1.1mm per layer.

[0069] S7: Slow cooling.

[0070] In some implementations, the perforated roller can be completely wrapped in asbestos cloth for slow cooling, and the wrapping thickness can be 4 to 10 millimeters.

[0071] S8: Roll surface inspection. Check the roll surface for macroscopic defects such as pores and cracks, and repair any defects. After grinding off the black skin on the cladding layer surface, use a chuck to inspect the roll surface profile, measure the hardness and elemental composition, and finally perform flaw detection.

[0072] Therefore, the present invention adopts a scheme of dividing the cladding area into sections, and the roller surface is cut with elongated grooves before laser cladding. After cladding, only the size of the elongated grooves needs to be restored, which avoids the disadvantages of local thinness of the cladding layer caused by grooving after cladding and poor accuracy of repeated clamping with large differences in grooving depth.

[0073] This invention repairs old perforated rollers using laser cladding, significantly reducing the wear rate of the roller surface and greatly improving the competitiveness of the production line.

[0074] Furthermore, the combination of the technical features in this case is not limited to the combination methods described in the claims of this case or the combination methods described in the specific embodiments. All technical features described in this case can be freely combined or combined in any way, unless they contradict each other.

[0075] It should also be noted that the embodiments listed above are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made thereto are those that can be directly derived or easily conceived by those skilled in the art from the content disclosed in the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A method of additive manufacturing of a seamless tube piercing roll applied to a seamless tube piercing roll comprising an entry cone and an exit cone abutting in their axial direction; characterized in that, The additive manufacturing method includes the following steps: The whole turning of the roll surface of the seamless steel tube piercing roll is performed: the turning depth is determined based on the set number of cladding layers, the maximum wear depth of the piercing roll roll surface and the single layer cladding thickness, so as to perform the whole turning of the roll surface of the piercing roll; the turning depth S 改车 is: S 改车 = (K-1) x S 单层 + S 最深 + 2-6; wherein K represents the set number of cladding layers, S 单层 represents the single layer cladding thickness; S 最深 represents the measured maximum wear depth of the perforated roller surface, wherein the unit parameters of the single layer cladding thickness, the maximum wear depth of the perforated roller surface and the turning depth are mm; Several elongated grooves distributed along the circumference are opened in the multi-layer cladding area on the roller surface, with intervals between each elongated groove. The length direction of the elongated grooves is consistent with the length direction of the seamless steel pipe piercing roller. The multi-layer cladding area is the roller surface of the inlet cone and the roller surface of the first section of the outlet cone connected to the inlet cone. The remaining part of the outlet cone is a single-layer cladding area. Preheat the roller surface of the seamless steel pipe piercing roller; At least one laser cladding is performed in the multi-layer cladding area, and the elongated groove is repaired after each laser cladding. A layer of laser cladding is applied to the entire roller surface, and the elongated groove is repaired after the laser cladding is applied. Cool slowly.

2. The method of additive manufacturing of a seamless steel tube piercing roll according to claim 1, characterized in that, The multi-layer cladding region includes multiple sub-regions with different numbers of cladding layers arranged along the axial direction of the seamless steel pipe piercing roller, wherein the number of cladding layers in each sub-region decreases along the direction from the inlet cone end face to the outlet cone end face.

3. The method of additive manufacturing of a seamless steel tube piercing roll according to claim 1, characterized in that, The first section of the outlet cone is a region extending 50mm from the highest point toward the end face of the outlet cone, where the highest point is the position where the outlet cone and the inlet cone meet.

4. The method of additive manufacturing of a seamless steel tube piercing roll according to claim 1, characterized in that, After the integral turning step of the seamless steel pipe piercing roll, and before the step of opening several elongated grooves distributed circumferentially in the multi-layer cladding area on the roll surface, the following steps are also included: A 30-60° chamfer is machined at the junction of the multi-layer cladding area and the single-layer cladding area.

5. The method of additive manufacturing of a seamless steel tube piercing roll according to claim 1, characterized in that, The starting position of the elongated groove in the length direction is 100-300mm away from the end face of the inlet cone.

6. The additive manufacturing method for seamless steel pipe piercing rolls as described in claim 1, characterized in that, The elongated groove has a length of 200-400mm, a width of 15-30mm, and a depth of 0.3-2mm.

7. The additive manufacturing method for seamless steel pipe piercing rolls as described in claim 1, characterized in that, A 30-60° chamfer is machined at the edge of the elongated groove.

8. The additive manufacturing method for seamless steel pipe piercing rolls as described in claim 1, characterized in that, In the step of preheating the roller surface of the seamless steel pipe piercing roller, the overall temperature of the roller surface is controlled to be ≥150℃, and the temperature of the cladding zone is 300~350℃.

9. The additive manufacturing method for seamless steel pipe piercing rolls as described in claim 1, characterized in that, The alloy powder used in laser cladding is either nickel-based alloy powder or cobalt-based alloy powder.

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