CN109079421B - A kind of method that locomotive buffer bar surface reconditioning remanufactures - Google Patents

Abstract

A method for repairing and remanufacturing the surface of a bumper rod of a motorcycle, the steps of which are as follows: S1, screening out repairable bumper rods to be repaired; S2, inspecting the amount of wear of the bumper rods to be repaired, respectively on the shaft sections of different radii of the bumper rods, Determine the area to be repaired according to the size of the wear amount, and process the groove to be repaired in the area to be repaired; S3, perform sandblasting, cleaning and preheating treatment on the buffer rod to be repaired; S4, fix one end of the buffer rod to be repaired on the variable On the positioner, the repair of the buffer rod to be repaired is completed by continuous circular welding of the groove to be repaired by the CMT automatic welding system; S5, performing post-weld slow cooling on the repaired buffer rod obtained in step S4; S6, repairing the buffer rod to the repaired area It is machined according to the size of the original drawing, and then sandblasted as a whole. The method of the invention has low cost, high efficiency and high repair quality, and the quality standard of a new part can be reached after being repaired and remanufactured by the method of the invention.

Description

A method for repairing and remanufacturing the surface of a locomotive buffer bar

technical field

The invention relates to a method for repairing and remanufacturing the surface of a buffer rod of a locomotive, and belongs to the technical field of surface repair and remanufacturing.

Background technique

With the rapid development of my country's economy in recent years, the transportation industry is in the stage of explosive growth. With the development of the transportation industry, the amount of scrap is also increasing, causing problems such as environmental pollution and waste of resources. Restoration and remanufacturing projects can alleviate the pressure on resources, have a prominent role in environmental protection, increase employment rates, contain high economic added value, and have good development prospects.

The repair and remanufacturing of locomotive parts has become a development trend for effective utilization of resources and reduction of enterprise costs. But on the whole, the repair and remanufacturing of locomotive parts and other fields in my country is still in the state of exploration. At the same time, the domestic repair and remanufacturing process is relatively simple, the basic research is insufficient, there are few fields involved, the product is single, and the market recognition is low.

The buffer rod is one of the important components of the locomotive and vehicle connection buffer system. During long-term use, problems such as reduced buffering effect, larger buffer distance, and increased noise are prone to occur. The main reason is that the working surface of the buffer rod , aging and cracks. It is scrapped every year due to wear, deformation, scratches, corrosion, etc., resulting in a waste of social resources. Therefore, repairing the failure area of the buffer rod to "restore size and improve performance" will not only restore the worn buffer rod to its performance, but also achieve the purpose of saving resources and protecting the environment, which has great economic benefits and social benefits. Therefore, there is an urgent need for a low-cost, high-efficiency, high-quality surface repair method for bumper rods.

Contents of the invention

The object of the present invention is to provide a low-cost, high-efficiency, high-quality method for repairing and remanufacturing the surface of a buffer bar that can reach the quality standard of a new part after repairing and remanufacturing.

The technical solution adopted by the present invention to realize the purpose of the invention is: a method for repairing and remanufacturing the surface of a locomotive bumper bar, the steps of which are as follows:

S1. Detect and screen the damaged buffer rods after disassembly, remove the buffer rods with cracks and unqualified coaxiality through X-ray inspection and coaxiality detection, and screen out the repairable buffer rods to be repaired;

S2. Check the wear amount of the buffer rod to be repaired, and determine the area to be repaired according to the size of the wear amount in the shaft sections of different radii of the buffer rod, and process the groove to be repaired in the area to be repaired, and the grooves at both ends of the groove The groove surface angle of the surface is 45°-70°, and the bottom surface between the two groove surfaces is an equiaxed rod;

S3. Perform sandblasting, cleaning and preheating treatment on the buffer rod to be repaired with the groove to be repaired;

S4. Fix one end of the buffer rod to be repaired on the positioner, and perform continuous annular welding on the groove to be repaired by the CMT automatic welding system composed of a CMT welding machine and an ABB robot to complete the repair of the buffer rod to be repaired, and obtain a repaired buffer rod; During the welding process, the rotation of the buffer rod to be repaired is realized through the positioner, and the welding torch of the CMT welding machine walks in a straight line along the axial direction of the buffer rod to be repaired;

The welding wire used for the continuous circular welding of the groove to be repaired by the CMT automatic welding system is a copper-plated solid core welding wire, the diameter of the welding wire is 1.2-1.4mm, and the welding wire composition is: C≤0.10wt%, Mn: 1.65% ~2.0wt%, Si: 0.55%~0.80wt%, S≤0.020wt%, P≤0.025wt%, Mo≤0.50wt%, Ti≤0.15wt%, Cr≤0.60wt%, W≤0.10wt%, Cu≤0.50wt% and the balance is Fe;

The welding parameters adopted by the CMT automatic welding system for continuous circular welding of the groove to be repaired are: welding current 130-170A, welding voltage 11-18V, arc length correction factor -10, wire feeding speed 3-6m/min, The shielding gas flow rate is 20-25L/min; the welding torch of the CMT welding machine travels in a straight line along the axial direction of the buffer rod to be repaired at a speed of 8-12mm/min, the arc extinguishing delay is 400-700s, and the welding torch angle is 60°-90° (the welding torch angle is Refers to the angle between the welding torch and the axial direction of the buffer rod to be repaired, that is, the angle between the welding torch and the bottom surface of the groove to be repaired); the parameter of the positioner to realize the rotation of the buffer rod to be repaired is: the linear speed is 6- 14mm/s, acceleration and deceleration time is 10ms;

S5. Slowly cool the repaired buffer rod obtained in step S4 after welding. The specific operation is: bury the repaired buffer rod that has just completed continuous circular welding with sand or asbestos wrapping, slowly cool to 200-250 ° C, and then air cool to room temperature;

S6. Machining the repaired area of the repaired buffer rod after the slow cooling treatment in step S5 according to the size of the original drawing, and then performing an overall sandblasting treatment on the repaired buffer rod.

Compared with prior art, the beneficial effect of the present invention is:

1. The CMT welding method is used to realize the repair, which has the characteristics of low welding heat input, small welding deformation, no spatter welding, low energy consumption, less pollution and good working environment. Using positioner and CMT automatic welding system to realize intelligent welding, simple operation, easy control, high welding efficiency, which is conducive to ensuring the stability of welding quality and improving production efficiency.

Two, the base material of the buffer rod is 45 steel, and the hardenability and cold cracking tendency of the carbon content 0.42-0.5 steel material are large. In the method of the present invention, preheating before welding, controlling heat input and post-welding heat treatment and other technological measures can prevent cold cracks. It can also solve the problem of hardening and embrittlement caused by high-carbon martensite in the welding heat-affected zone; the welding process and welding parameters adopted in the present invention can avoid the problem of strength and hardness reduction caused by softening in the high-temperature tempering zone.

3. During the repair process, only one end is supported and fixed, which can realize free deformation and reduce the residual stress generated.

4. Experimental verification, using the welding process of the present invention, uniquely designed welding wire design and welding parameters, the wear resistance of the repaired area is improved under the conditions of ensuring hardness, tensile, impact and other properties, and the metallurgical combination of the buffer rod repair layer and the substrate is realized. Good, characterized by magnetic particle inspection, the repaired buffer rod obtained by repairing and remanufacturing according to the present invention has no defects such as cracks, unfused, pores, inclusions, etc., the repair quality is good, the microstructure is fine, the heat-affected zone is less than 1.5mm, and the comprehensive mechanical properties It is equivalent to the base material, and can reach the quality standard of new parts after repair and remanufacturing.

5. In the repair process, the composition design of the welding wire is the key. The applicant adjusted the distribution ratio of the welding wire through a large number of experiments to obtain the technical effect of the application. The following briefly analyzes the role of several chemical components in the welding wire:

Si deoxidizer, alloying agent of weld metal, can reduce the oxygen content of weld metal, improve the impact toughness of weld metal, can form a mature toughening mechanism with Mn, and can play the role of joint deoxidation at the same time; Mn : Deoxidizer, alloying agent for weld metal; has an important influence on the strength and toughness of weld metal. Manganese can reduce the transformation temperature from austenite to ferrite and promote the formation of AF (acicular ferrite); the increase of manganese content can improve the low-temperature impact toughness of the weld, and can form MnS with S to reduce the impurity content of the weld; Mn It can effectively reduce the sulfur content in the weld metal, improve the low-temperature toughness of the weld metal, and increase the strength at the same time; Cr: corrosion resistance, transition alloy element Cr to the surfacing layer, the transition of elements plays a role in deoxidation and formation Hard phase; W: As a hard phase, it plays the role of wear resistance; Mo: Mo refines the grain size of the weld metal, which can significantly improve the strength of the weld metal, and an appropriate increase in Mo can improve the impact energy of the weld metal Beneficial effect; Ti: Ti can refine the weld metal structure, ensure that the weld metal obtains acicular ferrite structure, and ensure that the cladding metal obtains good mechanical properties.

6. Experimental verification, the repair buffer rod that has just completed continuous circular welding is first slowly cooled to 200-250°C, and then air-cooled to room temperature, which is not only conducive to eliminating residual stress and hardened structure, but also ensures that the hardness of the repaired area and the heat-affected zone are uniform. Within the technical requirements of HB220-250, reduce the hardened structure in the heat-affected zone to ensure that the hardness of the repaired buffer rod is equivalent to that of the new buffer rod; and the above-mentioned slow cooling operation can improve the impact performance and section elongation of the repaired area, ensuring that the repair is iron Ferrite and pearlite, eliminate bainite organization.

7. Before welding repair and after welding repair, the buffer rod is sandblasted. Sandblasting can not only remove oil and rust, but also reduce residual stress by knocking on the buffer. At the same time, the pressure generated by sandblasting The stress will offset the tensile stress of the buffer rod during use, which can prolong the service life.

Further, in step S2 of the present invention, when the wear depth of the worn part is 1-3mm, the groove face angle of the groove to be repaired in the area to be repaired is 45°-60°; the wear depth of the worn part When it is 3-7mm, the groove face angle of the groove to be repaired in the area to be repaired is 60°-70°.

If the wear is large and the angle of the groove surface is too small, it is easy to cause the slag to float out of the surface during the lap joint process, and finally cause the slag inclusion to increase with the wear depth. As the wear depth increases, the angle of the groove surface becomes larger, which is beneficial to the effective lap joint during the repair process, and eliminates defects such as inclusions formed on the groove surface. Experiments have verified that designing the angles of the above-mentioned groove surfaces according to different wear conditions is conducive to improving the repair quality.

Further, in step S3 of the present invention, the specific operation for preheating the buffer rod to be repaired is: to perform local preheating on the groove to be repaired and its surrounding area, the preheating temperature is 160±20°C, and the preheating time is 30 -40min. Ceramic heating blankets can be used for local preheating, and the preheating temperature should rise evenly, for example, the temperature can be raised to 160±20°C at a speed of 50-60°C/h, which can avoid the tendency of uneven temperature heating to produce cold cracks.

Experiments have proved that the above-mentioned preheating temperature and preheating time can improve the plasticity of the welding area and reduce residual stress; moreover, welding at the above-mentioned preheating temperature is conducive to preventing micro-cracks inside the buffer rod, and at the same time can avoid the welding repair area and heat loss. Cracks and hardened structures appear in the affected area.

Furthermore, the local preheating of the groove to be repaired and its surrounding area in the present invention refers to: the area extending 20-30 mm from both ends of the groove to be repaired on the buffer rod to be repaired.

In this way, on the one hand, the local temperature difference stress of the buffer rod can be reduced, the internal structure can be improved, and the hardened structure can be prevented or reduced; (At the ungrooved part) move 1-2mm as the starting point of welding, so as to ensure a good lap between the weld seam and the groove surface, and move 1-2mm more to the unworn part when the arc is turned off to ensure the completion of the repair. Preheating the area where the groove to be repaired extends 20-30mm from both ends can ensure a good lap between the weld and the groove surface.

Further, in step S4 of the present invention, the shielding gas used for continuous annular welding of the groove to be repaired by the CMT automatic welding system is 20% CO ₂ +80% Ar.

Through the test and verification of different processes, the simple use of _CO2 gas will cause large splashes and poor forming. During the welding process, the welding torch nozzle is prone to sticky slag, and then it is easy to fall into the molten pool to form slag inclusions as the welding process progresses. Wire burst phenomenon occurs. However, when Ar gas is used alone, the process is stable, and the penetration depth is not as good as that of mixed gas, and the cost of high-purity Ar is too high. Therefore, when mixed gas is used, the amount of _CO2 gas in the mixed gas directly affects the penetration depth and droplet transfer form during welding. . Experiments have proved that using 20% CO ₂ +80% Ar mixed gas as shielding gas can not only improve the anti-porosity performance of the welding area, control spatter, reduce post-weld slag removal, increase welding wire deposition rate, make the repair shape well, and reduce welding fumes , taking into account the repair quality and cost.

Further, step S4 of the present invention performs continuous annular welding on the groove to be repaired by the CMT automatic welding system to complete the repair process of the buffer rod to be repaired: if the length of the groove to be repaired is less than or equal to 20cm, one-time continuous annular welding is used to complete the repair , if the length of the groove to be repaired is greater than 20cm, segmental symmetrical continuous circular welding is used to complete the repair.

If the continuous welding time is too long, the heat accumulation of the buffer rod will be too much, and the deformation will occur. After the deformation, the stress will be concentrated, resulting in poor surface formation. After a lot of experiments, the above welding method can not only control the heat input, reduce the deformation, but also control The input affects tissue properties, softening the hardness of the repaired area.

Further, in step S3 and step S6 of the present invention, the specific operation of the sandblasting treatment is: use 40-50 mesh quartz sand to carry out comprehensive sandblasting treatment on the buffer rod to be repaired or the surface of the repaired buffer rod, and the blasting pressure is 0.6-0.8 MPa.

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a schematic diagram of the continuous circular welding of the groove to be repaired of the buffer rod to be repaired according to the embodiment of the present invention.

FIG. 2 is an enlarged schematic diagram of part A in FIG. 1 according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of one-time continuous annular welding to complete the repair according to the embodiment of the present invention.

Fig. 4 is a schematic diagram of repairing completed by segmented symmetrical continuous annular welding according to an embodiment of the present invention.

In the figure, 1.1 is the host part of the positioner, 1.2 is the chuck of the positioner, 1.3 is the guide rail of the positioner, 1.4 is the base of the positioner, 1.5 is the slider matching with the guide rail, and 2.1 is to be repaired The thick end of the buffer rod, that is, the large radius shaft section, 2.2 is the thin end of the buffer rod to be repaired, that is, the small radius shaft section, 3.0 is the welding torch of the CMT welding machine, 3.1 is the welding wire, 4.0 is the groove to be repaired, 4.1 is the groove to be repaired The groove surface of the groove to be repaired, 4.2 is the bottom surface of the groove to be repaired, θ is the angle of the groove surface, d is the processing depth of the groove to be repaired, 5.0 is the supporting roller fixedly installed on the slider 1.5, and the buffer rod to be repaired Swivels on support rollers.

Detailed ways

Example

A method for repairing and remanufacturing the surface of a locomotive bumper bar, the steps are as follows:

S1. Detect and screen the damaged buffer rods after disassembly, remove the buffer rods with cracks and unqualified coaxiality through X-ray inspection and coaxiality detection, and screen out the repairable buffer rods to be repaired;

S2. Check the wear amount of the buffer rod to be repaired, respectively on the shaft sections of different radii of the buffer rod (the buffer rod includes a thick end and a thin end, the thick end is a large-radius shaft segment, and the thin end is a small-radius shaft segment. The thick end and thin end of the buffer respectively determine the area to be repaired and process the groove to be repaired. In Figure 1, the thick end of the buffer rod to be repaired does not need to be repaired, only the thin end wear needs to be repaired, and the groove to be repaired is only made on the thin end ), determine the area to be repaired according to the size of the amount of wear, and process the groove to be repaired in the area to be repaired, the angle of the groove surface at both ends of the groove is 45°-70°, and the angle between the two groove surfaces The bottom surface is an equiaxed rod; optionally, when the wear depth of the worn part is 1-3mm, the groove surface angle of the groove to be repaired in the area to be repaired is 45°-60°; When the wear depth is 3-7mm, the groove surface angle of the groove to be repaired in the area to be repaired is 60°-70°; as shown in Figure 1 and Figure 2, 4.0 is the angle of the small radius shaft section of the buffer The groove to be repaired in the area to be repaired is in the shape of an equiaxed rod.

S3. Perform sandblasting, cleaning and preheating treatment on the buffer rod to be repaired with the groove to be repaired;

Optionally, the specific operation of the sandblasting treatment is: use 40-50 mesh quartz sand to perform comprehensive sandblasting treatment on the surface of the buffer rod to be repaired, and the sandblasting pressure is 0.6-0.8Mpa;

Optionally, the specific operation of cleaning is to use alcohol or acetone to clean first, and then use an iron brush to clean surface burrs, cotton and other sundries;

Optionally, the specific operation of the preheating treatment is: local preheating of the groove to be repaired and its surrounding area, the preheating temperature is 160±20°C, and the preheating time is 30-40min; The surrounding area for local preheating refers to the area where the groove of the buffer rod to be repaired extends 20-30mm from both ends of the groove to be repaired;

S4. Fix one end of the buffer rod to be repaired on the positioner, and use the CMT automatic welding system composed of CMT welding machine and ABB robot to perform continuous circular welding on the groove to be repaired to complete the repair of the buffer rod to be repaired; Figure 1 is the repair of the buffer rod to be repaired Schematic diagram of continuous circular welding of the groove to be repaired of the buffer rod;

Optionally, if the length of the area to be repaired is less than or equal to 20cm, one-time continuous annular welding is used to complete the repair, as shown in Figure 3, m and n are the two ends of the welding groove to be repaired, and the one-time continuous annular welding is It means that during the welding process, the welding torch walks from point n along the axial direction of the buffer rod to be repaired to point m to complete the welding repair; if the length of the area to be repaired is greater than 20 cm, segmental symmetrical continuous circular welding is used to complete the repair, as shown in Figure 4 Indicates that m and n are the two ends of the welding groove to be repaired, and the completion of the repair by segmental symmetrical continuous annular welding means that during the welding process, the welding torch first walks along the axial direction of the buffer rod to be repaired in a straight line from point n to the point m and n Stop welding at the dotted line in the center, move the welding torch to point m, and then walk straight along the axial direction of the buffer rod to be repaired from point m to the dotted line in the center of m and n to complete the welding repair;

During the welding process, the rotation of the buffer rod to be repaired is realized through the positioner, that is, the rotation of the buffer rod to be repaired is realized through the rotation of the chuck of the positioner; the welding torch of the CMT welding machine walks in a straight line along the axial direction of the buffer rod to be repaired;

The welding wire used for the continuous circular welding of the groove to be repaired by the CMT automatic welding system is a copper-plated solid core welding wire, the diameter of the welding wire is 1.2-1.4mm, and the welding wire composition is: C≤0.10wt%, Mn: 1.65% ~2.0wt%, Si: 0.55%~0.80wt%, S≤0.020wt%, P≤0.025wt%, Mo≤0.50wt%, Ti≤0.15wt%, Cr≤0.60wt%, W≤0.10wt%, Cu≤0.50wt% and the balance is Fe;

The welding parameters adopted by the CMT automatic welding system for continuous circular welding of the groove to be repaired are: welding current 130-170A, welding voltage 11-18V, arc length correction factor -10, wire feeding speed 3-6m/min, The shielding gas flow rate is 20-25L/min; the welding torch of the CMT welding machine travels in a straight line along the axial direction of the buffer rod to be repaired at a speed of 8-12mm/min, the arc extinguishing delay is 400-700s, and the welding torch angle is 60°-90°; The parameters of the positioner for the rotation of the buffer rod are: the linear speed is 6-14mm/s, and the acceleration and deceleration time is 10ms;

Optionally, the shielding gas used for the continuous annular welding is 20% CO ₂ +80% Ar;

S5. Slowly cool the repaired buffer rod obtained in step S4 after welding. The specific operation is: bury the repaired buffer rod that has just completed continuous circular welding with sand or asbestos wrapping, slowly cool to 200-250 ° C, and then air cool to room temperature;

S6. Machining the repaired area of the repaired buffer rod obtained through the slow cooling treatment in step S5 according to the size of the original drawing, and then performing overall sandblasting on the repaired buffer rod;

Optionally, the specific operation of the sandblasting treatment is: use 40-50 mesh quartz sand to perform comprehensive sandblasting treatment on the surface of the repaired buffer rod, and the sandblasting pressure is 0.6-0.8Mpa.

The present invention will be described in further detail below through specific examples.

Embodiment one

S1. Detect and screen the damaged buffer rods after disassembly, remove the buffer rods with cracks and unqualified coaxiality through X-ray inspection and coaxiality detection, and screen out the repairable buffer rods to be repaired;

S2. Check the wear amount of the buffer rod to be repaired, and determine the area to be repaired according to the size of the wear amount in the shaft sections of different radii of the buffer rod, and process the groove to be repaired in the area to be repaired; in this example, the thickness of the buffer rod to be repaired is The end diameter is Φ75mm, the maximum wear depth is 3mm, and the wear length is about 20cm; the thin end diameter is Φ48mm, the maximum wear depth is 3mm, and the wear length is about 12cm;

On the butt end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the butt end, and the groove to be repaired is processed in the area to be repaired. The processing depth d of the groove to be repaired is the maximum wear depth of the butt end, d=3mm, the length of the groove to be repaired is slightly longer than the wear length of the butt end (it is enough to ensure that the groove to be repaired covers all the worn parts), and the angle of the groove surface at both ends of the groove to be repaired is 60°, The bottom surface between the two groove surfaces is an equiaxed rod;

On the thin end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the thin end, and the groove to be repaired is processed in the area to be repaired, and the processing depth d of the groove to be repaired is the maximum wear depth of the thin end, d=3mm, the length of the groove to be repaired is slightly longer than the wear length of the thin end, the angle of the groove surface at both ends of the groove to be repaired is 60°, and the bottom surface between the two groove surfaces is an equiaxed rod;

S3. Perform sandblasting, cleaning and preheating treatment on the buffer rod to be repaired with the groove to be repaired;

The specific operation of sandblasting in this example is: use 40-mesh quartz sand to perform comprehensive sandblasting on the surface of the buffer rod to be repaired, and the sandblasting pressure is 0.6Mpa;

The specific operation of cleaning in this example is to use alcohol or acetone to clean first, and then use an iron brush to clean the surface burrs, cotton and other sundries;

The specific operation of the preheating treatment in this example is: local preheating of the groove to be repaired and its surrounding area, the preheating temperature is 140 ° C, and the preheating time is 30 minutes; the local preheating of the groove to be repaired and its surrounding area is carried out The hot surrounding area refers to the area extending 20mm from both ends of the groove to be repaired on the buffer rod to be repaired;

S4. Fix the thin end of the buffer rod to be repaired on the positioner, and use the CMT automatic welding system composed of CMT welding machine and ABB robot to perform continuous circular welding on the groove to be repaired to complete the repair of the buffer rod to be repaired; obtain the repaired buffer rod ;In this example, the area to be repaired at the thick end and the area to be repaired at the thin end are all repaired by one-time continuous annular welding; the welding wire used in this example is a solid core welding wire with a copper-plated surface, the diameter of the welding wire is 1.3mm, and the welding wire composition is: C: 0.086wt%, Mn: 1.65wt%, Si: 0.55wt%, S: 0.0059wt%, P: 0.0068wt%, Mo: 0.25wt%, Ti: 0.11wt%, Cr: 0.30wt%, W: 0.10wt%, the balance is Fe; the shielding gas used in continuous annular welding in this example is 20% CO ₂ +80% Ar; the welding parameters adopted are: welding current 130A, welding voltage 11V, arc length correction factor -10 , the wire feeding speed is 3m/min, the shielding gas flow rate is 20L/min; the welding torch of the CMT welding machine travels in a straight line along the axial direction of the buffer rod to be repaired at a speed of 12mm/min, the arc extinguishing delay is 400s, and the welding torch angle is 70°; the buffer to be repaired is realized The parameters of the positioner for the rotation of the rod are: the linear speed is 14mm/s, and the acceleration and deceleration time is 10ms;

S5. Perform slow cooling after welding on the repaired buffer rod obtained in step S4. In this example, the specific operation is: bury the repaired buffer rod that has just completed continuous circular welding with sand or asbestos wrapping, slowly cool to 200 ° C, and then air cool to room temperature;

S6. The repaired area of the repaired buffer rod obtained by the slow cooling treatment in step S5 is machined according to the size of the original drawing, and then the repaired buffer rod is subjected to overall sandblasting treatment; the specific operation of the sandblasting treatment in this example is: use 40 mesh quartz sand to The surface of the repaired buffer rod is fully sandblasted, and the sandblasting pressure is 0.7Mpa.

Embodiment two

S1. Detect and screen the damaged buffer rods after disassembly, remove the buffer rods with cracks and unqualified coaxiality through X-ray inspection and coaxiality detection, and screen out the repairable buffer rods to be repaired;

S2. Check the wear amount of the buffer rod to be repaired, and determine the area to be repaired according to the size of the wear amount in the shaft sections of different radii of the buffer rod, and process the groove to be repaired in the area to be repaired; in this example, the thickness of the buffer rod to be repaired is The end diameter is Φ75mm, the maximum wear depth is 4mm, and the wear length is about 18cm; the thin end diameter is Φ48mm, the maximum wear depth is 4mm, and the wear length is about 14cm;

On the butt end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the butt end, and the groove to be repaired is processed in the area to be repaired. The processing depth d of the groove to be repaired is the maximum wear depth of the butt end, d=4mm, the length of the groove to be repaired is slightly longer than the wear length of the butt end, the angle of the groove surface at both ends of the groove to be repaired is 65°, and the bottom surface between the two groove surfaces is an equiaxed rod;

On the thin end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the thin end, and the groove to be repaired is processed in the area to be repaired, and the processing depth d of the groove to be repaired is the maximum wear depth of the thin end, d=4mm, the length of the groove to be repaired is slightly longer than the wear length of the thin end, the angle of the groove surface at both ends of the groove to be repaired is 65°, and the bottom surface between the two groove surfaces is an equiaxed rod;

S3. Perform sandblasting, cleaning and preheating treatment on the buffer rod to be repaired with the groove to be repaired;

The specific operation of sandblasting in this example is: use 40-mesh quartz sand to carry out comprehensive sandblasting on the surface of the buffer rod to be repaired, and the sandblasting pressure is 0.7Mpa;

The specific operation of cleaning in this example is to use alcohol or acetone to clean first, and then use an iron brush to clean the surface burrs, cotton and other sundries;

The specific operation of the preheating treatment in this example is: local preheating of the groove to be repaired and its surrounding area, the preheating temperature is 160°C, and the preheating time is 35 minutes; the local preheating of the groove to be repaired and its surrounding area is carried out The hot surrounding area refers to the area extending 20mm from both ends of the groove to be repaired on the buffer rod to be repaired;

S4. Fix the thin end of the buffer rod to be repaired on the positioner, and use the CMT automatic welding system composed of CMT welding machine and ABB robot to perform continuous annular welding on the groove to be repaired to complete the repair of the buffer rod to be repaired; get the repair buffer Rod; in this example, the area to be repaired at the thick end and the area to be repaired at the thin end are repaired by one-time continuous annular welding; the welding wire used in this example is a solid wire with a copper-plated surface, the diameter of the welding wire is 1.2mm, and the composition of the welding wire is : C: 0.076wt%, Mn: 1.73wt%, Si: 0.60wt%, S: 0.01wt%, P: 0.012wt%, Mo: 0.32wt%, Ti: 0.15wt%, Cr: 0.04wt%, W : 0wt%, Cu: 0.075wt% and the balance is Fe; the shielding gas used for continuous annular welding in this example is 20% CO ₂ +80% Ar; the welding parameters adopted are: welding current 140A, welding voltage 13V, arc Long correction factor -10, wire feeding speed 4m/min, shielding gas flow rate 25L/min; CMT welder’s welding torch travels in a straight line along the axial direction of the buffer rod to be repaired at a speed of 11mm/min, arc extinguishing delay is 500s, and the welding torch angle is 90° ; The parameters of the positioner to realize the rotation of the buffer rod to be repaired are: the linear speed is 12mm/s, and the acceleration and deceleration time is 10ms;

S5. Slowly cool the repaired buffer rod obtained in step S4 after welding. In this example, the specific operation is: bury the repaired buffer rod that has just completed continuous circular welding with sand or asbestos wrapping, slowly cool to 250 ° C, and then air cool to room temperature;

S6. The repaired area of the repaired buffer rod obtained by the slow cooling treatment in step S5 is machined according to the size of the original drawing, and then the repaired buffer rod is subjected to overall sandblasting treatment; the specific operation of the sandblasting treatment in this example is: use 40 mesh quartz sand to The surface of the repaired buffer rod is fully sandblasted, and the sandblasting pressure is 0.6Mpa.

Hardness test, abrasive wear test, impact energy test and tensile test are carried out on the repaired area of the repaired buffer rod.

The hardness test shows that: the average hardness HB of the repaired area is 246, which is equivalent to the base material of the buffer rod;

The results of the abrasive wear test show that under the same conditions, the wear resistance of the repaired area of the repaired bumper rod is equivalent to that of the base material of the bumper rod.

The impact energy test shows that: compared with the average impact energy of the new buffer rod of the same base material of 37J, the average impact energy of the thin end of the repaired buffer rod is 60J, which is 62% higher than that of the base material; the impact energy of the thick end of the repaired buffer rod It reached 59J, and the impact energy increased by 59.4%.

The tensile test shows that the average tensile strength of the repaired buffer rod is 783Mpa, the reduction of area is 44%, and the elongation after fracture is 12.1%. 54%, elongation after fracture 8.4%) have similar mechanical properties, fully meet the technical standards, and meet the requirements of use.

Embodiment three

S1. Detect and screen the damaged buffer rods after disassembly, remove the buffer rods with cracks and unqualified coaxiality through X-ray inspection and coaxiality detection, and screen out the repairable buffer rods to be repaired;

S2. Check the wear amount of the buffer rod to be repaired, and determine the area to be repaired according to the size of the wear amount in the shaft sections of different radii of the buffer rod, and process the groove to be repaired in the area to be repaired; in this example, the thickness of the buffer rod to be repaired is The end diameter is Φ75mm, the maximum wear depth is 5mm, and the wear length is about 25cm; the thin end diameter is Φ48mm, the maximum wear depth is 5mm, and the wear length is about 16cm;

On the butt end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the butt end, and the groove to be repaired is processed in the area to be repaired. The processing depth d of the groove to be repaired is the maximum wear depth of the butt end, d=5mm, the length of the groove to be repaired is slightly longer than the wear length of the butt end, the angle of the groove surface at both ends of the groove to be repaired is 65°, and the bottom surface between the two groove surfaces is an equiaxed rod;

On the thin end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the thin end, and the groove to be repaired is processed in the area to be repaired, and the processing depth d of the groove to be repaired is the maximum wear depth of the thin end, d=5mm, the length of the groove to be repaired is slightly greater than the wear length of the thin end, the angle of the groove surface at both ends of the groove to be repaired is 65°, and the bottom surface between the two groove surfaces is an equiaxed rod;

S3. Perform sandblasting, cleaning and preheating treatment on the buffer rod to be repaired with the groove to be repaired;

The specific operation of sandblasting in this example is: use 50-mesh quartz sand to carry out comprehensive sandblasting on the surface of the buffer rod to be repaired, and the sandblasting pressure is 0.8Mpa;

The specific operation of cleaning in this example is to use alcohol or acetone to clean first, and then use an iron brush to clean the surface burrs, cotton and other sundries;

The specific operation of the preheating treatment in this example is: local preheating of the groove to be repaired and its surrounding area, the preheating temperature is 160°C, and the preheating time is 40 minutes; the local preheating of the groove to be repaired and its surrounding area is carried out The hot surrounding area refers to the area extending 20mm from both ends of the groove to be repaired on the buffer rod to be repaired;

S4. Fix the thin end of the buffer rod to be repaired on the positioner, and use the CMT automatic welding system composed of CMT welding machine and ABB robot to perform continuous circular welding on the groove to be repaired to complete the repair of the buffer rod to be repaired; obtain the repaired buffer rod ; In this example, the area to be repaired at the thick end is repaired by segmented symmetrical continuous annular welding; the area to be repaired at the thin end is repaired by one-time continuous annular welding; The welding wire composition is: C: 0.088wt%, Mn: 1.68wt%, Si: 0.57wt%, S: 0.009wt%, P: 0.017wt%, Mo: 0wt%, Ti: 0.13wt%, Cr : 0.35wt%, W: 0wt%, Cu: 0.094wt%, the balance is Fe; the shielding gas used for continuous annular welding in this example is 20% CO ₂ +80% Ar; the welding parameters adopted are: welding current 160A, welding voltage 15V, arc length correction factor -10, wire feeding speed 5m/min, shielding gas flow rate 25L/min; the welding torch of the CMT welding machine travels at a linear speed of 9mm/min along the axial direction of the buffer rod to be repaired. The time is 500s, the welding torch angle is 90°; the parameters of the positioner to realize the rotation of the buffer rod to be repaired are: when repairing the thick end of the buffer rod, the linear speed is 11mm/s; when repairing the thin end of the buffer rod, the linear speed is 6mm/s, the acceleration and deceleration time is 10ms;

S5. Slowly cool the repaired buffer rod obtained in step S4 after welding. In this example, the specific operation is: bury the repaired buffer rod that has just completed continuous circular welding with sand or asbestos wrapping, slowly cool to 250 ° C, and then air cool to room temperature;

S6. The repair area of the repaired buffer rod obtained by the slow cooling treatment in step S5 is machined according to the size of the original drawing, and then the repaired buffer rod is subjected to overall sandblasting; the specific operation of sandblasting in this example is: use 50 mesh quartz sand to The surface of the repaired buffer rod is fully sandblasted, and the sandblasting pressure is 0.8Mpa.

Hardness test, abrasive wear test, impact energy test and tensile test are carried out on the repaired area of the repaired buffer rod.

The hardness test shows that: the average hardness HB of the repaired area is 242, which is equivalent to the base material of the buffer rod;

The results of the abrasive wear test show that under the same conditions, the wear resistance of the repaired area of the repaired bumper rod is equivalent to that of the base material of the bumper rod.

The impact energy test shows that: compared with the average impact energy of the new buffer rod with the same base material of 37J, the average impact energy of the thin end of the repaired buffer rod is 48J, which is 29.7% higher than that of the base material; the impact energy of the thick end of the repaired buffer rod It reached 43J, and the impact energy increased by 16.2%.

The tensile test shows that the average tensile strength of the repaired buffer rod is 720Mpa, the reduction of area is 49%, and the elongation after fracture is 11.2%. 54%, elongation after fracture 8.4%) have similar mechanical properties, fully meet the technical standards, and meet the requirements of use.

Embodiment four

S1. Detect and screen the damaged buffer rods after disassembly, remove the buffer rods with cracks and unqualified coaxiality through X-ray inspection and coaxiality detection, and screen out the repairable buffer rods to be repaired;

S2. Check the wear amount of the buffer rod to be repaired, and determine the area to be repaired according to the size of the wear amount in the shaft sections of different radii of the buffer rod, and process the groove to be repaired in the area to be repaired; in this example, the thickness of the buffer rod to be repaired is The end diameter is Φ75mm, the maximum wear depth is 6mm, and the wear length is about 23cm; the thin end diameter is Φ48mm, the maximum wear depth is 4mm, and the wear length is about 14cm;

On the butt end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the butt end, and the groove to be repaired is processed in the area to be repaired. The processing depth d of the groove to be repaired is the maximum wear depth of the butt end, d=6mm, the length of the groove to be repaired is slightly longer than the wear length of the butt end, the angle of the groove surface at both ends of the groove to be repaired is 67°, and the bottom surface between the two groove surfaces is an equiaxed rod;

On the thin end of the buffer rod to be repaired, the area to be repaired is determined according to the maximum wear depth and wear length of the thin end, and the groove to be repaired is processed in the area to be repaired, and the processing depth d of the groove to be repaired is the maximum wear depth of the thin end, d=4mm, the length of the groove to be repaired is slightly longer than the wear length of the thin end, the angle of the groove surface at both ends of the groove to be repaired is 67°, and the bottom surface between the two groove surfaces is an equiaxed rod;

S3. Perform sandblasting, cleaning and preheating treatment on the buffer rod to be repaired with the groove to be repaired;

The specific operation of sandblasting in this example is: use 50-mesh quartz sand to carry out comprehensive sandblasting on the surface of the buffer rod to be repaired, and the sandblasting pressure is 0.8Mpa;

The specific operation of cleaning in this example is to use alcohol or acetone to clean first, and then use an iron brush to clean the surface burrs, cotton and other sundries;

The specific operation of the preheating treatment in this example is: local preheating of the groove to be repaired and its surrounding area, the preheating temperature is 180 ° C, and the preheating time is 40 minutes; the local preheating of the groove to be repaired and its surrounding area is carried out The hot surrounding area refers to the area extending 20mm from both ends of the groove to be repaired on the buffer rod to be repaired;

S4. Fix the thin end of the buffer rod to be repaired on the positioner, and use the CMT automatic welding system composed of CMT welding machine and ABB robot to perform continuous circular welding on the groove to be repaired to complete the repair of the buffer rod to be repaired; obtain the repaired buffer rod ; In this example, the area to be repaired at the thick end is repaired by segmented symmetrical continuous annular welding; the area to be repaired at the thin end is repaired by one-time continuous annular welding; The welding wire composition is: C: 0.10wt%, Mn: 2.0wt%, Si: 0.80wt%, S: 0.02wt%, P: 0.025wt%, Mo: 0.50wt%, Ti: 0.15wt%, Cr: 0.60wt%, W: 0.05wt%, Cu: 0.5wt%, and the balance is Fe; the shielding gas used for continuous annular welding in this example is 20% CO ₂ +80% Ar; the welding parameters adopted are: The welding current is 170A, the welding voltage is 18V, the arc length correction factor is -10, the wire feeding speed is 6m/min, the shielding gas flow rate is 22L/min; The arc delay is 700s, and the welding torch angle is 60°; the parameters of the positioner to realize the rotation of the buffer rod to be repaired are: when repairing the thick end of the buffer rod, the line speed is 11mm/s; when repairing the thin end of the buffer rod, the line speed is The speed is 6mm/s, and the acceleration and deceleration time is 10ms;

S5. Slowly cool the repaired buffer rod obtained in step S4 after welding. In this example, the specific operation is: bury the repaired buffer rod that has just completed continuous circular welding with sand or asbestos wrapping, slowly cool to 230 ° C, and then air cool to room temperature;

S6. The repair area of the repaired buffer rod obtained by the slow cooling treatment in step S5 is machined according to the size of the original drawing, and then the repaired buffer rod is subjected to overall sandblasting; the specific operation of sandblasting in this example is: use 50 mesh quartz sand to The surface of the repaired buffer rod is fully sandblasted, and the sandblasting pressure is 0.8Mpa.

Claims (7)

1. a kind of method that locomotive buffer bar surface reconditioning remanufactures, its step are as follows:

S1, detection screening is carried out to the buffer bar haveing damage under disassembly, has by x-ray inspection and concentricity detection removal and splits The underproof buffer bar of line, concentricity filters out recoverable buffer bar to be repaired；

S2, the abrasion loss for examining buffer bar to be repaired, respectively in the shaft part of buffer bar different radii, take measurements by abrasion determine to Restoring area, and groove to be repaired is processed in area to be repaired, the bevel angle of the groove both ends to be repaired groove face is 45 ° -70 °, the bottom surface between two groove faces is equal shafts；

S3, blasting treatment, cleaning and the pre-heat treatment are once carried out to the buffer bar to be repaired for processing groove to be repaired；

S4, one end of buffer bar to be repaired is fixed on deflection machine, the CMT being made up of CMT welding machine and ABB robot is automatic Welding system carries out the reparation that buffer bar to be repaired is completed in continuous circular shape welding to groove to be repaired, obtains repairing buffer bar；Weldering In termination process, the rotation of buffer bar to be repaired is realized by deflection machine, the welding gun of CMT welding machine is along buffer bar axial direction straight line to be repaired Walking；

It is described that groove to be repaired is carried out continuous circular shape to weld used welding wire being copper coating by CMT robot welding system Solid core welding wire, gage of wire 1.2-1.4mm, component of weld wire are as follows: C≤0.10wt%, Mn:1.65%~2.0wt%, Si: 0.55%~0.80wt%, S≤0.020wt%, P≤0.025wt%, Mo≤0.50wt%, Ti≤0.15wt%, Cr≤ 0.60wt%, W≤0.10wt%, Cu≤0.50wt% surplus are Fe；

It is described to be to welding parameter used by groove to be repaired progress continuous circular shape welding by CMT robot welding system: weldering Connect electric current 130-170A, weldingvoltage 11-18V, arc length correction factor -10, wire feed rate 3-6m/min, protective gas flow velocity 20-25L/min；The welding gun of CMT welding machine is 8-12mm/min, blow-out delay along the buffer bar axial direction straight line speed of travel to be repaired 400-700s, 60 ° -90 ° of angle of welding gun；Realizing the deflection machine parameter of buffer bar rotation to be repaired is: linear velocity 6-14mm/s, Acceleration and deceleration time is 10ms；

S5, postheating processing is carried out to the reparation buffer bar that step S4 is obtained, concrete operations are: will just complete continuous circular shape The reparation buffer bar of welding buries sand or then asbestos package, slow cooling are air-cooled to room temperature to 200-250 DEG C；

S6, handle to obtain the restoring area for repairing buffer bar according to the machining of original part drawing size, so to by step S5 slow cooling Whole blasting treatment is carried out to reparation buffer bar afterwards.

2. the method that a kind of locomotive buffer bar surface reconditioning according to claim 1 remanufactures, it is characterised in that: the step In rapid S2, when the wearing depth of abrading section is 1-3mm, in area to be repaired, the bevel angle of the groove to be repaired of processing is 45°-60°；When the wearing depth of abrading section is 3-7mm, the bevel angle of the groove to be repaired of processing in area to be repaired It is 60 ° -70 °.

3. the method that a kind of locomotive buffer bar surface reconditioning according to claim 1 remanufactures, it is characterised in that: the step In rapid S3, the concrete operations for carrying out the pre-heat treatment to buffer bar to be repaired are: to groove to be repaired and its peripheral region carry out office Portion's preheating, preheating temperature are 160 ± 20 DEG C, preheating time 30-40min.

4. the method that a kind of locomotive buffer bar surface reconditioning according to claim 3 remanufactures, it is characterised in that: described right The peripheral region that groove and its peripheral region to be repaired carry out local preheating refers to: the slope of groove to be repaired on buffer bar to be repaired Mouth extends the region of 20-30mm towards both ends.

5. the method that a kind of locomotive buffer bar surface reconditioning according to claim 1 remanufactures, it is characterised in that: the step In rapid S4, carrying out continuous circular shape welding protective gas used to groove to be repaired by CMT robot welding system is 20%CO₂ + 80%Ar.

6. the method that a kind of locomotive buffer bar surface reconditioning according to claim 1 remanufactures, it is characterised in that: the step Rapid S4 carries out the repair process that buffer bar to be repaired is completed in continuous circular shape welding to groove to be repaired by CMT robot welding system In: if area to be repaired length is less than or equal to 20cm, is welded using disposable continuous circular shape and complete to repair, if to be repaired When zone length is greater than 20cm, complete to repair using segmentation Symmetrical Continuous annular solder.

7. the method that a kind of locomotive buffer bar surface reconditioning according to claim 1 remanufactures, it is characterised in that: the step In rapid S3 and step S6, the concrete operations of blasting treatment are: to buffer bar to be repaired or being repaired slow using the quartz sand of 40-50 mesh Punch surface carries out comprehensive blasting treatment, and sandblasting pressure is 0.6-0.8Mpa.