CN105349993B - Cladding method for inner hole of upright post - Google Patents

Abstract

The invention relates to a cladding method for the inner hole of a column, which belongs to the technical field of laser cladding methods. The inner hole of the column to be processed is clad with alloy powder to obtain a cladding layer. The invention effectively improves the wear resistance of the inner hole of the column Performance, prolong the service life of the column, improve the operability of laser cladding on the inner hole of the column, the alloy powder and the inner hole of the column form an effective metallurgical bond, and promote the cladding layer to have good ductility and toughness, and friction The coefficient is low, which can meet the needs of high-tech and automation development of enterprises.

Description

A cladding method for the inner hole of a column

technical field

The invention belongs to the technical field of laser cladding methods, and in particular relates to a cladding method for an inner hole of a column.

Background technique

Under the influence of the working environment, corrosion, wear and other failures are common in heavy mining equipment, such as hydraulic support column cylinders and other inner hole parts, the inner hole corrosion, wear and other damage will cause major safety hazards and property losses.

At present, the surface repair process of inner hole parts mainly includes diameter reduction method, welding repair method, spraying metal material and inner bushing method, but the above-mentioned procedures are complicated and expensive, and there is a gap between the repaired coating and the substrate. Insufficient inter-bonding force, the coating cannot meet the corresponding thickness requirements, and the inner hole parts cannot meet the application requirements in the engineering field after repairing.

The rapid development of domestic laser technology, the use of laser cladding technology to form a cladding layer on the outer surface of the component can not only improve the wear resistance and corrosion resistance of the component, but also repair the worn and corroded components. However, the inner space of the inner hole of the column is limited, and the existing laser and cladding process cannot realize the cladding of the inner hole of the column, which hinders the industrial application of laser technology. How to carry out laser cladding on the inner hole of the column is a technical problem worth studying.

Contents of the invention

Aiming at the deficiencies of the existing technology, in order to solve the above problems, a method is proposed to effectively improve the wear resistance of the inner hole of the column, prolong the service life of the column, improve the operability of laser cladding on the inner hole of the column, and adapt to the The cladding method for the inner hole of the column required by the high-tech and automation development of the enterprise.

To achieve the above object, the present invention provides the following technical solutions:

The invention discloses a cladding method for the inner hole of a column. The inner hole of the column to be processed is clad with alloy powder to obtain a cladding layer.

Further, the cladding method of the cladding layer is straight cladding, which effectively reduces the energy consumption of the shaft processing machine tool, reduces the influence of cladding heat on the column to be processed, and adopts periodic lap joints to finally realize multi-pass lap joints , to ensure the uniformity of cladding forming.

Further, the cross-section of the column to be processed is circular or polygonal.

Further, the cladding method of the cladding layer is:

(1) The column to be processed is fixed on the tooling, the laser head is placed inside the column to be processed, and the laser head is fed in the direction of the main axis of the column to be processed, and the laser head is provided with a smoke removal device and a feeder. Powder device;

(2) Synchronous powder feeding mode is adopted, and the laser head moves from one end of the column to be processed to the other end along the main axis direction of the column to be processed to complete a feed movement;

(3) The laser head resets along the main axis direction of the column to be processed, and performs the next feed movement;

(4) Step (3) is repeated to clad the alloy powder on the inner hole of the column to be processed to obtain a cladding layer.

Further, in the cladding process, the outer surface of the column to be processed is subjected to heat dissipation treatment simultaneously, and the heat dissipation treatment method is as follows:

A cold air source is set on the outer surface of the column to be processed, and the cold air source is fed synchronously with the laser head to cool down the column after the laser head is clad. The pressure of the cold air source is 5-20bar, and the output cold air temperature The temperature is 0-8℃, and the intake air volume is 0.7-1.2m ³ /min.

Further, when the cross-section of the column to be processed is circular, the cladding method is as follows:

(1) The tooling drives the column to be processed to rotate around the main axis of the column to be processed. During a feed movement of the laser head along the main axis of the column to be processed, the laser head melts from one end of the inner hole of the column to be processed. Cladding to the other end to obtain the Nth cladding strip;

(2) The laser head is reset along the main axis direction of the column to be processed, and cladding on the side of the Nth cladding strip from one end of the column to be processed to the other end to form the N+1th cladding strip Cladding strips, and the overlapping rate of N and N+1 cladding strips is 30%-50%;

(3) Step (2) is repeated until the cladding strip completely covers the inner hole of the column to be processed to obtain a cladding layer.

Further, the rotation of the tool is synchronized with the step movement of the laser, and the rotation amplitude of the tool is the same as the step movement of the laser.

Further, when the cross-section of the column to be processed is polygonal, the cladding method is as follows:

(1) During a feed movement of the laser head along the main axis direction of the column to be processed, the laser head is clad from one end of the inner hole of the column to be processed to the other end to obtain the Nth cladding strip;

(2) The laser head is reset along the main axis direction of the column to be processed, and cladding on the side of the Nth cladding strip from one end of the column to be processed to the other end to form the N+1th cladding strip Cladding strips, and the overlapping rate of N and N+1 cladding strips is 30%-50%;

(3) Repeat step (2) until the cladding strip completely covers the inner hole of the same plane;

(4) The tooling drives the column to be processed to rotate, so that the laser head is positioned at the inner hole of another plane;

(5) Steps (1)-(4) are repeated until the cladding strip completely covers the inner hole of the column to be processed to obtain a cladding layer.

Further, the linear velocity of the laser is 500-750mm/min, the power is 7000-7500W, the step distance is 1/3-1/2 of the laser spot diameter, the powder feeding speed is 20-30g/min, and the carrier gas volume is 8 -15L/min, the thickness of one side of the cladding strip is 1-2mm.

Further, the alloy powder includes the following formula components:

C: 0.04-0.08 parts, Mo: 12-16 parts, W: 4.5-5.5 parts, Ni: 24.2-43.9 parts, Fe: 5-7 parts, Mn: 0.7-1.0 parts, Cr: 13-15 parts, Si : 0.3-0.5 parts, V: 0.5-0.7 parts.

The alloy powder contains Ni and Cr, so that the alloy powder has the wear resistance and corrosion resistance that meets the requirements of the inner hole of the column, and a certain amount of Mo is added to the alloy powder, which helps to improve the ductility of the cladding layer And toughness, at the same time, promote the cladding layer to have the characteristics of low friction coefficient.

The beneficial effects of the present invention are:

1. The present invention adopts the direct paving cladding method to form a cladding layer on the inner hole of the column to be processed, which can effectively improve the wear resistance of the inner hole of the column and prolong the service life of the column.

2. The present invention is applicable to columns to be processed with various cross-sectional shapes, has the characteristics of a wide application range, and significantly improves the operability of laser cladding on the inner holes of the columns.

3. The present invention adopts the direct paving cladding method, and simultaneously performs heat dissipation and smoke removal operations, which can effectively avoid a sharp rise in the temperature of some columns, and timely absorb the smoke generated during the cladding process, which helps to improve the quality of the cladding layer and prevents The cladding layer is cracked and deformed, the yield rate is high, and the working efficiency is high.

4. The present invention optimally sets various parameters of the laser and the powder feeder, which can ensure effective metallurgical bonding between the alloy powder and the inner hole of the column, and save production costs.

5. The present invention optimizes the formula and components of the alloy powder, so that the cladding layer has better ductility and toughness, and at the same time, helps to reduce the friction coefficient of the cladding layer.

6. The invention can program the rotation speed of the tooling and the feed frequency of the laser head, so as to meet the needs of high-tech and automation development of enterprises.

Description of drawings

Fig. 1 is a schematic diagram of the straight cladding mode of the present invention;

Fig. 2 is a hardness gradient graph of samples of the present invention.

Wherein, in Fig. 2, the abscissa represents the distance between the detection point and the surface of the cladding layer in mm, and the ordinate represents the microhardness value.

In the attached drawings: the column to be processed 1, the Nth cladding strip 2, and the N+1 cladding strip 3.

Detailed ways

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments in this application, those of ordinary skill in the art will Other similar embodiments obtained without creative work shall all fall within the scope of protection of this application.

Embodiment one:

A cladding method for an inner hole of a column, comprising the following steps:

(1) pretreat the inner hole of the column 1 to be processed, remove the burrs and rust on the surface of the inner hole, and expose the metallic luster;

(2) Fix the column 1 to be processed on the tooling, place the laser head inside the column 1 to be processed, and the laser head moves in the direction of the main axis of the column 1 to be processed, and the laser head is provided with a smoke removal The device and powder feeding device can absorb the smoke generated during the cladding process in time;

(3) Adopt synchronous powder feeding mode, the laser head moves from one end of the column to be processed 1 to the other end along the main axis direction of the column to be processed 1, and completes a feed movement;

(4) The laser head resets along the main axis direction of the column 1 to be processed, and performs the next feed movement;

(5) Step (4) is repeated to clad the alloy powder on the inner hole of the column 1 to be processed to obtain a cladding layer.

In this embodiment, the alloy powder includes the following formula components:

C: 0.04 parts, Mo: 12 parts, W: 4.5 parts, Ni: 24.2 parts, Fe: 5 parts, Mn: 0.7 parts, Cr: 13 parts, Si: 0.3 parts, V: 0.5 parts.

The cross-section of the column 1 to be processed is circular, and its length is 2m. The method of cladding by straight laying is adopted, and the specific method of cladding alloy powder in its inner hole is as follows:

(1) The tooling drives the column 1 to be processed to rotate around the main axis of the column 1 to be processed, and during a feed movement of the laser head along the direction of the main axis of the column 1 to be processed, the laser head starts from the column 1 to be processed One end of the hole is clad to the other end to obtain the Nth cladding strip 2 with a single side thickness of 1 mm;

(2) The laser head is reset along the main axis direction of the column 1 to be processed, and on the side of the Nth cladding strip 2, it is overlapped and clad from one end of the column 1 to be processed to the other end, forming the N+th 1 cladding strip 3, the thickness of one side is 1mm, and the overlapping ratio of N and N+1 cladding strips is 30%;

(3) Step (2) is repeated until the cladding strip completely covers the inner hole of the column 1 to be processed to obtain a cladding layer;

(4) Carry out turning treatment on the cladding layer, the thickness of one side of turning is 0.5 mm, and the thickness of the single cladding layer remaining in the inner hole of the column 1 to be processed is 0.5 mm.

In this embodiment, a carbon dioxide laser is used to generate a rectangular laser spot, the laser spot size is 15mm*2.5mm, the linear speed is 500mm/min, the power is 7000W, the step distance is 5mm, the powder feeding speed is 20g/min, and the carrier gas The volume is 8L/min, the rotation of the tooling is synchronized with the step distance movement of the laser, and the rotation amplitude of the tooling is the same as the step distance movement amplitude of the laser.

In the cladding process, a cold air source is provided on the outer surface of the column 1 to be processed, and the cold air source is fed synchronously with the laser head to cool down the column after the laser head is clad. The pressure of the cold air source is 5bar, the output cold air temperature is 8°C, and the intake air volume is 0.7m ³ /min.

Embodiment two:

The same part of this embodiment and Embodiment 1 will not be described again, the difference is:

The alloy powder includes the following formula components: C: 0.06 parts, Mo: 14 parts, W: 5.0 parts, Ni: 36.5 parts, Fe: 5 parts, Mn: 0.7 parts, Cr: 13 parts, Si: 0.3 parts, V: 0.5 parts.

The length of the column 1 to be processed is 3m, and the cross section of the column 1 to be processed is a square, and the cladding method is as follows:

(1) During a feed movement of the laser head along the main axis direction of the column 1 to be processed, the laser head is clad from one end of the inner hole of the column 1 to be processed to the other end to obtain the Nth cladding strip 2 , the thickness of one side is 1.6mm;

(2) The laser head is reset along the main axis direction of the column 1 to be processed, and on the side of the Nth cladding strip 2, it is overlapped and clad from one end of the column 1 to be processed to the other end, forming the N+th 1 cladding strip 3, the thickness of one side is 1.6mm, and the overlapping rate of cladding strips N and N+1 is 45%;

(3) Repeat step (2) until the cladding strip completely covers the inner hole of the same plane;

(4) The tooling drives the column 1 to be processed to rotate, so that the laser head is positioned at the inner hole of another adjacent plane;

(5) Steps (1)-(4) are repeated until the cladding strip completely covers the inner hole of the column 1 to be processed to obtain a cladding layer;

(6) Carry out turning treatment on the cladding layer, the thickness of one side of turning is 1.2 mm, and the single layer thickness of the cladding layer remaining in the inner hole of the column 1 to be processed is 0.4 mm.

In this embodiment, a semiconductor laser is selected, the laser spot is rectangular, and its size is 14mm*2mm. The linear velocity of the laser is 580mm/min, the power is 7300W, the step distance is 7mm, the powder feeding speed is 25g/min, and the carrier gas The volume is 11 L/min, the pressure of the cold air source is 9 bar, the output cold air temperature is 6° C., and the intake air volume is 1.0 m ³ /min.

Embodiment three:

The same part of this embodiment and Embodiment 1 will not be described again, the difference is:

The alloy powder includes the following formula components: C: 0.08 parts, Mo: 16 parts, W: 5.5 parts, Ni: 43.9 parts, Fe: 7 parts, Mn: 1.0 parts, Cr: 15 parts, Si: 0.5 parts, V: 0.7 parts.

The length of the column 1 to be processed is 2.5m, and the cross section of the column 1 to be processed is a regular hexagon, and the cladding method is as follows:

(1) During a feed movement of the laser head along the main axis direction of the column 1 to be processed, the laser head is clad from one end of the inner hole of the column 1 to be processed to the other end to obtain the Nth cladding strip 2 , the thickness of one side is 2mm;

(2) The laser head is reset along the main axis direction of the column 1 to be processed, and on the side of the Nth cladding strip 2, it is overlapped and clad from one end of the column 1 to be processed to the other end, forming the N+th 1 cladding strip 3, the thickness of one side is 2mm, and the overlapping ratio of N and N+1 cladding strips is 50%;

(3) Repeat step (2) until the cladding strip completely covers the inner hole of the same plane;

(4) The tooling drives the column 1 to be processed to rotate, so that the laser head is positioned at the inner hole of another plane symmetrical thereto;

(5) Repeat steps (1)-(3) until the cladding strip completely covers the inner hole of the same plane;

(6) The tooling drives the column 1 to be processed to rotate, so that the laser head is positioned at the inner hole of another plane adjacent to it, and steps (1)-(3) are repeated until the cladding strip covers the inner hole of the same plane. The hole is fully covered;

(7) Repeat steps (4)-(6) until the cladding strip completely covers the inner hole of the column 1 to be processed to obtain a cladding layer;

(8) Carry out turning treatment on the cladding layer, the thickness of one side of turning is 1.3 mm, and the single layer thickness of the cladding layer remaining in the inner hole of the column 1 to be processed is 0.7 mm.

In this embodiment, a fiber laser is selected, the laser spot is rectangular, its size is 17mm*3mm, the linear velocity of the laser is 750mm/min, the power is 7500W, the step distance is 8.5mm, the powder feeding speed is 30g/min, and the current carrying The gas volume is 15 L/min, the pressure of the cold air source is 20 bar, the output cold air temperature is 0° C., and the intake air volume is 1.2 m ³ /min.

In addition, in the straight cladding method, the Nth cladding strip 2 and the N+1th cladding strip 3 can be clad at intervals until the cladding strips completely cover the inner wall of the column 1 to be processed, And the overlapping rate of adjacent cladding strips is 30-50%, so as to obtain the cladding layer.

Comparative experiment one:

Get a square column with a cross-section that has a wear phenomenon, its side length is 600mm, its length is 2m, and its material is a 27SiMn seamless steel pipe. It is repaired by the cladding method described in Embodiment 2 of the present invention. A sample of 60mm×60mm is taken from the finished product, and the thickness of the cladding layer of the sample is 0.4mm.

The sample was sanded and polished, and the HVS-1000A digital microhardness tester was used for hardness testing, and the testing points were taken at an interval of 0.5mm. The hardness gradient curve of the sample is shown in Figure 2.

It can be seen from Figure 2 that within the thickness range of the cladding layer, the hardness of the cladding layer is 300-320HV, and outside the thickness range of the cladding layer, the hardness of the substrate is 230-300HV, and the cladding layer and The hardness of the matrix is relatively stable, and the performance is stable, and the hardness of the cladding layer is slightly higher than the hardness of the matrix, which can effectively improve the wear resistance of the inner hole of the column, and at the same time, facilitate machining such as turning of the cladding layer operate.

Comparative experiment two:

Take the sample obtained in comparative experiment 1 and mark it as sample 1, take 60mm×60mm sample 2 on the column base in comparative experiment 1, and weigh the sample 1 and sample 2 respectively after cleaning and drying. Take the weight as the weight before the experiment, carry out the grinding operation with the 45 steel respectively, the grinding time is controlled to 1.5h, weigh the weight after cleaning and drying again, and use it as the weight after the experiment, calculate the weight loss due to wear, and repeat Three times, the experimental data obtained are shown in Table 1:

Table 1:

sample Weight loss at one time wear/g Secondary wear loss weight/g Lost weight after three wears/g Sample one 0.0025 0.002 0.002 Sample two 0.0075 0.008 0.007

The above experiments were carried out in the laboratory of Shandong Energy Heavy Equipment Group Han's Remanufacturing Co., Ltd.

Through the analysis of the above experimental data, the three abrasion losses of each sample are relatively close, indicating that the sample 1 and sample 2 have relatively high stability.

In the three grinding processes, the wear loss weight of the sample one was significantly lower than the wear loss weight of the sample two, indicating that the inner hole of the column repaired by the straight cladding described in the present invention has a high resistance to wear. The abrasive performance is better than that of the column matrix.

The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention, and should not limit the scope of the present invention. within the scope of the invention.

Claims (3)

1. A cladding method for the inner hole of a column, characterized in that: cladding alloy powder in the inner hole of the column to be processed to obtain a cladding layer, the cladding mode of the cladding layer is straight cladding, the The alloy powder includes the following formula components: C: 0.04-0.08 parts, Mo: 12-16 parts, W: 4.5-5.5 parts, Ni: 24.2-43.9 parts, Fe: 5-7 parts, Mn: 0.7-1.0 parts, Cr: 13-15 parts, Si: 0.3-0.5 parts, V: 0.5-0.7 parts; The cladding method of the cladding layer is: (1) Fix the column to be processed on the tooling, place the laser head inside the column to be processed, and the laser head moves in the direction of the main axis of the column to be processed, and the laser head is equipped with a smoke removal device and a conveyor Powder device; (2) Using the synchronous powder feeding method, the laser head moves from one end of the column to be processed to the other end along the main axis of the column to be processed, and completes a feeding movement; (3) The laser head resets along the main axis direction of the column to be processed, and performs the next feed movement; (4) Repeat step (3) to clad the alloy powder in the inner hole of the column to be processed to obtain a cladding layer. The linear speed of the laser is 500-750mm/min, the power is 7000-7500W, and the step distance is the diameter of the laser spot 1/3-1/2, the powder feeding speed is 20-30g/min, the carrier gas volume is 8-15L/min, and the thickness of one side of the cladding strip is 1-2mm; When the cross-section of the column to be processed is circular, the cladding method is as follows: (1) The tooling drives the column to be processed to rotate around the main axis of the column to be processed. During a feed movement of the laser head along the main axis of the column to be processed, the laser head melts from one end of the inner hole of the column to be processed. Cladding to the other end to obtain the Nth cladding strip; (2) The laser head is reset along the main axis direction of the column to be processed, and cladding on the side of the Nth cladding strip from one end of the column to be processed to the other end to form the N+1th cladding strip Cladding strips, and the overlap rate of N and N+1 cladding strips is 30%-50%; (3) Repeat step (2) until the cladding strip completely covers the inner hole of the column to be processed to obtain a cladding layer; When the cross section of the column to be processed is polygonal, the cladding method is as follows: (1) During a feed movement of the laser head along the main axis direction of the column to be processed, the laser head is clad from one end of the inner hole of the column to be processed to the other end to obtain the Nth cladding strip; (2) The laser head is reset along the main axis direction of the column to be processed, and cladding on the side of the Nth cladding strip from one end of the column to be processed to the other end to form the N+1th cladding strip Cladding strips, and the overlap rate of N and N+1 cladding strips is 30%-50%; (3) Repeat step (2) until the cladding strip completely covers the inner hole of the same plane; (4) The tooling drives the column to be processed to rotate, so that the laser head is positioned at the inner hole of another plane; (5) Steps (1)-(4) are repeated until the cladding strip completely covers the inner hole of the column to be processed to obtain a cladding layer. 2. The cladding method for the inner hole of a column according to claim 1, characterized in that: in the cladding process, the outer surface of the column to be processed is simultaneously subjected to heat dissipation treatment, and the heat dissipation treatment The method is: A cold air source is set on the outer surface of the column to be processed, and the cold air source is fed synchronously with the laser head to cool down the column after the laser head is clad. The pressure of the cold air source is 5-20bar, and the output cold air temperature The temperature is 0-8℃, and the intake air volume is 0.7-1.2m ³ /min. 3 . The cladding method for the inner hole of a column according to claim 2 , wherein the rotation of the tool is synchronized with the step movement of the laser, and the rotation range of the tool is the same as the step movement of the laser. 4 .