A composite reinforced conveying roller for a steel pipe production line and a manufacturing method thereof

Abstract

The application discloses a composite reinforced conveying roller for a steel pipe production line, wherein the roller surface is a V-shaped groove, and the V-shaped groove is composed of a cast steel base body, a middle laser cladding layer and a surface spraying layer. Meanwhile, the application discloses a manufacturing method of the composite reinforced conveying roller for the steel pipe production line, which comprises the following steps: ① rough turning of the conveying roller base body; ② laser cladding of the middle layer; ③ turning of the cladding layer; the laser cladding is carried out in the groove by using a semiconductor laser, and the cladding thickness is 1.6-1.8 mm; ④ spraying; a ceramic coating with a thickness of 0.1-0.2 mm is prepared on the cladding layer by using supersonic flame spraying; ⑤ polishing; ⑥ size inspection and coloring flaw detection; and ⑦ final inspection. The composite reinforced conveying roller for the steel pipe production line has excellent high-temperature resistance, cold-heat fatigue resistance and wear resistance by the combination of the middle laser cladding layer and the surface spraying layer, and the service life of the steel pipe conveying roller is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of steel metallurgy, in particular to a kind of steel pipe production line composite reinforced conveying roller and its manufacturing method. BACKGROUND

[0002] Steel pipe conveying roller is an important component on the seamless steel pipe production line of steel plant, which mainly plays the role of conveying steel pipe. The conveying roller is usually subjected to water cooling and impact and friction of steel pipe during work. Its failure mainly includes high-temperature wear, cold and hot fatigue, impact wear, etc. The surface failure of steel pipe conveying roller can seriously affect the surface quality of steel pipe, causing scratches on the surface of steel pipe.

[0003] At present, the common surface strengthening methods of steel pipe conveying roller mainly include surfacing and spray welding. The steel pipe conveying roller strengthened by surfacing usually has coarse surfacing layer organization, insufficient wear resistance, and early wear grooves during use, thereby causing scratches on the surface of steel pipe. The steel pipe conveying roller strengthened by spray welding usually has chipping phenomenon due to long-term cold and hot fatigue and impact. The steel pipe conveying roller manufactured by using these methods cannot meet the increasing requirements of long service life and high quality of steel plant, and the current general service life is about one year. Therefore, it is necessary to develop new technical processes to prolong the service life of steel pipe conveying roller.

[0004] Chinese patent CN201310264296.3 discloses a process for laser cladding wear-resistant and heat-resistant alloy coating on hot-rolled seamless steel pipe conveying roller. Although this process improves the wear resistance and high-temperature resistance to some extent, it mainly has the following problems: (1) high difficulty in process control during cladding: high-hardness alloy powder is mixed with tungsten carbide, and cracks are easily generated in the cladding layer. Once cracks exist in the cladding layer, the base is corroded by cooling water during use, resulting in peeling of the coating; (2) the roller surface of steel pipe conveying roller is generally V-shaped, and the high-hardness ceramic coating can only be processed by grinding, which has high processing difficulty and cost. Therefore, the process for manufacturing steel pipe conveying roller by using laser cladding method has the disadvantages of uncontrollable quality and high cost. SUMMARY

[0005] The present application provides a kind of steel pipe production line composite reinforced conveying roller and its manufacturing method, which combines the intermediate laser cladding layer and the surface spray coating, so that the steel pipe production line composite reinforced conveying roller has excellent high-temperature resistance, cold and hot fatigue resistance and wear resistance, prolonging the service life of the steel pipe conveying roller. At the same time, the processing difficulty of the method is small, the quality is controllable, and the processing cost is low.

[0006] The present application provides a kind of steel pipe production line composite reinforced conveying roller, which has a V-shaped groove on the roller surface, and the V-shaped groove is composed of a cast steel base, an intermediate laser cladding layer and a surface spray coating.

[0007] Wherein, the cast steel base is annealed after casting, and the hardness is 220-260HB.

[0008] Wherein, the chemical composition and mass percentage of the laser cladding layer are: 28-32% Cr, 1-3% Ni, 2-3% Mo, 1-2% Si, 1-2% B, 0.8-1.2% C, 5-8% W, and the rest is Co.

[0009] Wherein, the chemical composition and mass percentage of the sprayed layer are: 88-90% WC, 10-12% Co.

[0010] Wherein, the effective thickness of the laser cladding layer is 1.0-1.2mm, and the effective thickness of the sprayed layer is 0.1-0.2mm.

[0011] Wherein, the hardness of the laser cladding layer is 45-50HRC, and the hardness of the sprayed layer is 1200±100Hv.

[0012] The manufacturing method of the composite reinforced conveying roller of the steel pipe production line comprises the following steps:

[0013] ① Rough turning of the conveying roller base: turning the conveying roller blank, and processing grooves according to the actual use area, the groove depth is 1.2-1.4mm;

[0014] ② Laser cladding of the intermediate layer: laser cladding is carried out in the groove by using a semiconductor laser, and the cladding thickness is 1.6-1.8mm; the chemical composition and mass percentage of the laser cladding layer are: 28-32% Cr, 1-3% Ni, 2-3% Mo, 1-2% Si, 1-2% B, 0.8-1.2% C, 5-8% W, and the rest is Co;

[0015] ③ Turning of the cladding layer: the conveying roller is cooled to room temperature, the cladding layer is processed by using a lathe, the cladding layer is bright in the round, and the remaining thickness of the cladding layer is ensured to be 1.0-1.2mm.

[0016] ④ Spraying: a 0.1-0.2mm thick ceramic coating is prepared on the cladding layer by using supersonic flame spraying; the chemical composition and mass percentage of the sprayed layer are: 88-90% WC, 10-12% Co;

[0017] ⑤ Polishing: the sprayed layer is polished by using a diamond abrasive belt, and the roughness after polishing is Ra 1.6-3.2;

[0018] ⑥ Dimension inspection and dye penetrant testing: the size after processing is inspected according to the processing process requirements, and the wear-resistant layer is subjected to dye penetrant testing to ensure that there is no crack and other defects;

[0019] ⑦ Final inspection: the finished conveying roller is inspected according to the drawing and technical agreement requirements.

[0020] In step 2, the laser cladding process parameters are as follows: a circular spot is used, the spot diameter is 5mm, the laser power is 2800-3200W, the scanning speed is 600-800mm / min, the powder feeding rate is 40-45g / min, and the overlap rate is 45%-50%.

[0021] In step 4, the spraying process parameters are as follows: supersonic spraying is used, the gun tube size is 6 inches, the oxygen is 1950-2000scfh, the kerosene is 6.6-7.0 gal / hr, and the powder feeding rate is 53-58g / min.

[0022] The principle and advantages of the steel pipe production line composite reinforced conveying roller and the manufacturing method thereof are as follows: 1. the middle laser cladding layer is made of cobalt-based alloy, has excellent high-temperature resistance and cold and hot fatigue resistance, and the cladding layer will not crack and is firmly combined with the base; 2. the surface spraying layer is made of metal ceramic and has a hardness of 1200±100Hv and excellent wear resistance; 3. the surface spraying layer is prepared by a supersonic spraying process, and the roughness is generally Ra4-6, the surface roughness is good, and the subsequent only needs to be polished to meet the roughness requirement of the finished product, and the process is easy to implement; 4. if the spraying layer is directly prepared on the cast steel base, the eggshell effect will usually occur: the spraying layer is usually 0.1-0.2mm, although it has excellent wear resistance, but due to the soft base, under the impact, the coating is easily broken like an eggshell, and the present application solves this problem by setting the middle laser cladding layer with a hardness of 45-50HRC. In summary, the combination of the middle laser cladding layer and the surface spraying layer makes the steel pipe production line composite reinforced conveying roller have excellent high-temperature resistance, cold and hot fatigue resistance and wear resistance, and prolongs the service life of the steel pipe production line composite reinforced conveying roller, which can reach 1.5-2 years. At the same time, the processing difficulty of the method is small, the quality is controllable, and the processing cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Fig. 1 is a schematic diagram of the steel pipe production line composite reinforced conveying roller of the present application;

[0024] Figure 2 Fig. 4 is a flow chart of the manufacturing method of the steel pipe production line composite reinforced conveying roller of the present application. DETAILED DESCRIPTION

[0025] In order to better understand the present application, the present application will be further described in detail below in combination with examples.

[0026] Example 1

[0027] The specification of a certain seamless pipe production line conveying roller is The size of the conveying roller is selected as ZG35Mn casting as the conveying roller base, the casting is annealed heat treatment; the conveying roller manufacturing method comprises the following steps:

[0028] ① Rough turning of the conveying roller base: turning the conveying roller blank, and processing grooves according to the actual use area, the groove depth is 1.2mm;

[0029] ② Laser cladding intermediate layer: laser cladding is carried out in the groove by using a semiconductor laser, and the cladding thickness is 1.6mm; the chemical composition and mass percentage of the intermediate cladding layer are as follows: 30%Cr, 3%Ni, 2%Mo, 1%Si, 1%B, 1.2%C, 6%W, and the rest is Co; the laser cladding process parameters are as follows: a circular spot is used, the spot diameter is 5mm, the laser power is 3200W, the scanning speed is 800mm / min, the powder feeding speed is 45g / min, and the overlap rate is 50%;

[0030] ③ Turning the cladding layer: the conveying roller is cooled to room temperature, the cladding layer is processed by using a lathe, the cladding layer is bright in the round, and the remaining thickness of the cladding layer is ensured to be 1.1mm;

[0031] ④ Spraying: a 0.1mm-thick ceramic coating is prepared on the cladding layer by using high-speed flame spraying, and the chemical composition and mass percentage of the sprayed layer are as follows: 88%WC and 12%Co. The spraying process parameters are as follows: high-speed spraying is adopted, the gun barrel size is 6 inches, the oxygen is 1950scfh, the kerosene is 6.6gal / hr, and the powder feeding speed is 53g / min;

[0032] ⑤ Polishing: diamond abrasive belt is used for polishing treatment of the sprayed layer, and the roughness after polishing is 1.6-3.2;

[0033] ⑥ Dimension inspection and dye penetrant testing: the size after processing is inspected according to the processing process requirements, and the dye penetrant testing is carried out on the wear-resistant layer to ensure that there is no crack and other defects;

[0034] ⑦ Final inspection: the finished conveying roller is inspected according to the drawing and technical agreement requirements.

[0035] Example 2

[0036] The conveying roller of a seamless pipe production line has the specification of ZG35Mn casting with the size of is selected as the conveying roller base, and the casting is annealed heat treatment; the conveying roller manufacturing method comprises the following steps:

[0037] ① Rough turning of the conveying roller base: turning the conveying roller blank, and processing grooves according to the actual use area, the groove depth is 1.4mm;

[0038] The intermediate laser cladding layer is prepared by using a semiconductor laser in the groove, and the cladding thickness is 1.8 mm; the chemical composition and mass percentage of the intermediate cladding layer are as follows: 28% of Cr, 1% of Ni, 2% of Mo, 1% of Si, 1% of B, 1.0% of C, 5% of W, and the rest of Co; the laser cladding process parameters are as follows: a circular spot is used, the spot diameter is 5 mm, the laser power is 3000 W, the scanning speed is 600 mm / min, the powder feeding speed is 40 g / min, and the overlap rate is 45%;

[0039] The turning cladding layer is prepared by using a lathe to process the cladding layer after the conveying roller is cooled to room temperature, the cladding layer is bright in the round, and the remaining thickness of the cladding layer is ensured to be 1.2 mm;

[0040] The spraying is performed on the cladding layer by using a high-velocity oxygen fuel (HVOF) to prepare a ceramic coating with a thickness of 0.2 mm, the chemical composition and mass percentage of the sprayed layer are as follows: 90% of WC and 10% of Co, and the spraying process parameters are as follows: the HVOF is used, the gun tube size is 6 inches, the oxygen flow rate is 2000 scfh, the kerosene flow rate is 7 gal / hr, and the powder feeding speed is 58 g / min;

[0041] The polishing is performed on the sprayed layer by using a diamond abrasive belt, and the roughness after polishing is 1.6-3.2;

[0042] The size inspection and dye penetrant testing are performed on the wear-resistant layer according to the machining process requirements, so that no cracks and other defects are ensured;

[0043] The final inspection is performed on the finished conveying roller according to the drawing and technical agreement requirements.

[0044] The steel pipe production line composite reinforced conveying roller has excellent high-temperature resistance, cold and hot fatigue resistance, and wear resistance by the combination of the intermediate laser cladding layer and the surface sprayed layer, and the service life of the steel pipe conveying roller is prolonged, and the service life can reach 1.5-2 years. Meanwhile, the manufacturing method has small machining difficulty, controllable quality, and low machining cost.

Claims

1. A composite reinforced conveying roller for a steel pipe production line, the roller surface being a V-shaped groove, the V-shaped groove being composed of a cast steel base, a middle laser cladding layer and a surface spraying layer; the cast steel base is annealed after casting and has a hardness of 220-260 HB; the chemical composition of the laser cladding layer is as follows in terms of percentage by mass: 28-32% Cr, 1-3% Ni, 2-3% Mo, 1-2% Si, 1-2% B, 0.8-1.2% C, 5-8% W, and the balance Co; the chemical composition of the spraying layer is as follows in terms of percentage by mass: 88-90% WC, 10-12% Co; the hardness of the laser cladding layer is 45-50 HRC, and the hardness of the spraying layer is 1200±100 HV; and a manufacturing method thereof comprises the following steps: ① Rough turning of the base of the conveying roller: turning the conveying roller blank to form grooves according to the actual use area, groove depth 1.2-1.4mm; ② Laser cladding of the intermediate layer: laser cladding in the grooves using a semiconductor laser, cladding thickness 1.6-1.8mm; ③ Turning of the cladding layer: cooling the conveying roller to room temperature, turning the cladding layer using a lathe, the cladding layer being smooth and bright, ensuring that the remaining thickness of the cladding layer is 1.0-1.2mm; ④ Spraying: spraying a 0.1-0.2mm thick ceramic coating on the cladding layer using high velocity oxy-fuel spraying; ⑤ Polishing: polishing the sprayed layer using a diamond abrasive belt, the roughness after polishing being Ra 1.6-3.2; ⑥ Dimensional inspection and dye penetrant inspection: inspecting the dimensions after processing according to the processing requirements, and performing dye penetrant inspection on the wear-resistant layer to ensure that there are no cracks; ⑦ Final inspection: inspecting the finished conveying roller according to the drawing and technical agreement requirements.

2. The composite reinforced conveyor roller for a steel pipe production line according to claim 1, characterized in that: The effective thickness of the laser cladding layer is 1.0-1.2mm, and the effective thickness of the sprayed layer is 0.1-0.2mm.

3. The composite reinforced conveyor roller for a steel pipe production line according to claim 1, characterized in that: The laser cladding process parameters in step ② are: using a circular spot, spot diameter 5mm, laser power 2800-3200W, scanning speed 600-800mm / min, powder feeding rate 40-45g / min, and overlap rate 45%-50%.

4. The steel pipe line composite reinforced conveyor roller as set forth in claim 1, characterized by: The spraying process parameters in step ④ are: using high velocity spraying, gun size 6 inches, oxygen 1950-2000scfh, kerosene 6.6-7.0gal / hr, and powder feeding rate 53-58g / min.

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