WO2024093184A1 - Method for improving bonding strength of rail flash-butt welded joint - Google Patents

Method for improving bonding strength of rail flash-butt welded joint Download PDF

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Publication number
WO2024093184A1
WO2024093184A1 PCT/CN2023/093540 CN2023093540W WO2024093184A1 WO 2024093184 A1 WO2024093184 A1 WO 2024093184A1 CN 2023093540 W CN2023093540 W CN 2023093540W WO 2024093184 A1 WO2024093184 A1 WO 2024093184A1
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WIPO (PCT)
Prior art keywords
flash
rail
mass fraction
stage
forging
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PCT/CN2023/093540
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French (fr)
Chinese (zh)
Inventor
陆鑫
李大东
王若愚
白威
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攀钢集团攀枝花钢铁研究院有限公司
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Priority to AU2023216810A priority Critical patent/AU2023216810A1/en
Publication of WO2024093184A1 publication Critical patent/WO2024093184A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00—Resistance welding; Severing by resistance heating
    • B23K11/04—Flash butt welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00—Resistance welding; Severing by resistance heating
    • B23K11/36—Auxiliary equipment
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium

Definitions

  • the invention belongs to the technical field of rail welding, and in particular relates to a method for improving the bonding strength of a rail flash butt welding joint.
  • Mobile flash welding due to its small equipment and easy mobility, is often used for welding on the track laying site, while fixed rail flash welding usually fixes the welding equipment in the factory, so it is also usually called factory welding or base welding. In addition to the application scenario, the biggest difference between the two is the way to heat the rails. Mobile flash welding heats the rails through intermittent pulsating flash blasting or continuous flash blasting, so mobile flash welding can be divided into pulsating flash and continuous flash. Fixed flash welding is usually done by directly short-circuiting the rails and heating them using resistance heat. The heating process is not (or only slightly) accompanied by flash, and is often referred to as short-circuit preheating flash welding.
  • the mainstream international standards for rail flash welding mainly include China Railway Industry Standard Series Standard TB/T 1632.2-2014 "Rail Welding Part 2: Flash Welding", American Railway Engineering Association Manual AMERICAN RARILWAY ENGINEERING AND MAINTENANCE-OF-WAY ASSOCIATION (AREMA), European Standard BS EN 14587-3:2012, Rail way applications-Track-Flash butt welding of rails.
  • Part 3 Welding in association with crossing construction and Australian Standard AS1085.20-2012
  • Railway track material Part 20 Welding of steel rail. All current standards and enterprise technical requirements applicable to flash welding of pearlite rails have made specific provisions on the microstructure of rail flash welds.
  • TB/T 1632.2 stipulates that the microstructure of the rail joint weld and heat-affected zone should be pearlite, a small amount of ferrite may appear, and there should be no harmful structures such as martensite or bainite; AMEMA stipulates that the rail joint weld and heat-affected zone are expected to be 100% pearlite.
  • the hardness of the longitudinal section of the rail flash weld joint that is, after the rail is cut in half along the longitudinal rolling direction of the rail, the hardness value within the range of 3 to 5 mm below the running surface of the joint and 20 mm on both sides of the joint fusion line exceeding the width of the heat affected zone, is tested.
  • Some standards use Rockwell hardness, some use Vickers hardness, or both.
  • the hardness of the rail weld joint is an important factor affecting the smoothness of the high-speed railway track. Only when the hardness level of the joint is equivalent to that of the parent material can the joint have consistent wear resistance with the line rail during the service life.
  • the current problem is that the joint has a softening zone in both the welding state and the heat treatment state, and saddle-shaped wear will occur during service, resulting in deterioration of the line smoothness.
  • the correct post-weld treatment process can improve the joint organization, reduce the softening degree, and meet the wear resistance requirements of the joint as much as possible.
  • the static bending test of the rail flash weld joint is the most widely used overall performance evaluation method for rail joints at home and abroad, and is stipulated in all rail joint inspection standards. It mainly includes two indicators, namely load and deflection.
  • the static bending test uses a three-point or four-point support method to apply load to the rail joint at a certain loading rate until the load reaches the standard value and the maximum deflection is greater than the standard value.
  • the static bending performance of the joint is judged to be qualified.
  • Different rail types correspond to different load and deflection values.
  • the European standard BS EN14587-2:2009 requires that the minimum load and deflection of the joint be no less than 1600KN and 20mm respectively (60kg/m rail, rail head under pressure).
  • the European standard BS EN14587-2:2009 requires that the minimum stress at the bottom of the joint rail be 900MPa, and the converted minimum load and deflection are no less than 1670KN and 20mm respectively (60kg/m rail, rail head under pressure).
  • my country's static bending standard requirements are that the breaking load is not less than 1450kN (60kg/m, rail head under pressure), There is no requirement for deflection.
  • the static bending load mainly reflects the joint strength, joint appearance and internal defect indicators, and the deflection mainly reflects the joint toughness indicator. If the joint welding process is poor, it is very likely that the joint will break before reaching the load value specified in the standard due to defects such as gray spots, lack of fusion or overburning, or because the joint heat input and upsetting amount are not matched properly, or the post-weld treatment method is improper, resulting in the joint being too hard or too soft, so that the joint deflection does not meet the standard requirements.
  • the railway engineering field urgently needs a method to improve the bonding strength of rail flash butt welded joints, so as to effectively ensure that the static bending performance of rail flash welded joints is greatly improved.
  • a welding method for internal damage resistant pearlite rails or high strength and toughness pearlite rails is provided, which can effectively reduce the generation of abnormal defects in the microstructure of the welded joints, thereby ensuring the safety of railway operation.
  • the present invention provides a method for improving the bonding strength of a rail flash butt weld joint, wherein the method uses a mobile flash welder to implement a welding process, wherein the welding process includes pre-flash, flash, accelerated burning, upsetting and forging; after the welding process is completed, the joint is naturally cooled in the air to room temperature;
  • the upsetting amount in the upsetting stage is 5.0mm ⁇ 18.0mm; the forging pressure in the forging stage is 60t ⁇ 80t.
  • the steel rail is selected from a pearlite steel rail having a carbon mass fraction of 0.60wt% to 0.90wt% and a hypereutectoid steel rail having a carbon mass fraction of 0.90wt% to 1.20wt%.
  • the pearlite rail comprises the following components: carbon mass fraction is 0.60% to 0.90%, silicon mass fraction is 0.10% to 1.00%, manganese mass fraction is 0.60% to 1.50%, phosphorus and sulfur mass fractions are both less than 0.020%, chromium mass fraction is less than 0.3% and vanadium mass fraction is less than 0.01%.
  • the hypereutectoid rail comprises the following components: the mass fraction of carbon is 0.90% to 1.20%, the mass fraction of silicon is 0.10% to 1.00%, the mass fraction of manganese is 0.60% to 1.50%, The mass fractions of phosphorus and sulfur are both less than 0.020%, the mass fraction of chromium is less than 0.3%, and the mass fraction of vanadium is less than 0.01%.
  • the charged upsetting time in the upsetting stage is 0.1s to 2.0s, and the upsetting timing is 1.0s to 3.0s.
  • the rail consumption in the forging stage is 2.0 mm to 4.0 mm
  • the forging time is 1.5 s to 3.0 s
  • the average speed is 0.60 mm/s to 2.60 mm/s.
  • the voltage of the pre-flash stage is 370V to 440V and the voltage time is 45s to 65s, the current value is 180A to 300A, the pre-flash distance is 2mm to 10mm, and the flash speed is 0.1mm/s to 0.6mm/s.
  • current setting value 1 is 180A ⁇ 250A
  • current setting value 2 is 200A ⁇ 270A
  • current setting value 3 is 220A ⁇ 300A.
  • the voltage in the flashing stage is 320V to 390V and the voltage time is 80s to 140s, the current value is 180A to 300A, and the flashing speed is 0.1mm/s to 0.6mm/s.
  • current setting value 1 is 180A ⁇ 250A
  • current setting value 2 is 200A ⁇ 270A
  • current setting value 3 is 220A ⁇ 300A.
  • the voltage of the accelerated burning stage is 380V to 450V
  • the current is 180A to 300A
  • the acceleration speed is 0.5mm/s to 2.0mm/s.
  • current setting value 1 is 180A ⁇ 250A
  • current setting value 2 is 200A ⁇ 270A
  • current setting value 3 is 220A ⁇ 300A.
  • the present invention also provides a steel rail welded by the above method.
  • the present invention mainly provides a method for improving the bonding strength of rail flash butt welding joints for pearlite rails with a carbon mass fraction of 0.60% to 0.90% and hypereutectoid rails with a carbon mass fraction of 0.90% to 1.20%.
  • the rail welds welded by the method have no gray spots, unwelded or overburned Welding defects such as rough rail fracture can be effectively ensured to greatly improve the static bending performance of the rail flash welded joint.
  • the method for improving the bonding strength of rail flash butt welding joints of the present invention heats the rails in the early and middle heating stages by a flash method different from the pulsating flash in the prior art, and at the same time removes the pressure holding stage in the prior art and replaces it with a forging stage.
  • the forging stage of the method for improving the bonding strength of rail flash butt welding joints of the present invention adopts hydraulic flow control, accompanied by displacement changes, and the joint bonding strength is greatly improved through the newly added forging.
  • the "joint” or “weld joint” is an area with a length of 80-120 mm including the weld and/or heat-affected zone obtained after welding, and the center of the area is the rail weld.
  • the "room temperature” is a temperature in the range of 5-40°C.
  • the embodiments of the present invention mainly provide a method for improving the bonding strength of the flash butt welded joints of the pearlite rails with a carbon mass fraction of 0.60% to 0.90% and the hypereutectoid rails with a carbon mass fraction of 0.90% to 1.20%.
  • the rail welds welded by the method have no welding defects such as gray spots, unwelded and over-burned, and the rail fracture is rough, which can effectively ensure that the static bending performance of the flash butt welded joints of the rails is greatly improved.
  • the above method for improving the bonding strength of rail flash butt welding joints is implemented by using a rail mobile flash welding machine.
  • the entire welding process includes five main stages: pre-flash, flash, accelerated burning, top forging and forging. After the flash welding is completed, the joint is naturally cooled to room temperature in the air.
  • the pearlite rail has a carbon mass fraction of 0.60% to 0.90%.
  • the main chemical components of the pearlite rail include carbon mass fraction of 0.60% to 0.90%, silicon mass fraction of 0.10% to 1.00%, manganese mass fraction of 0.60% to 1.50%, phosphorus and sulfur mass fractions not exceeding 0.020%, chromium mass fraction not exceeding 0.3% and vanadium mass fraction not exceeding 0.01%.
  • the minimum tensile strength of pearlite rail is 800MPa and the minimum hardness of rail head is 250HB.
  • the above-mentioned hypereutectoid rail has a carbon mass fraction of 0.90% to 1.20%.
  • the main chemical components of the hypereutectoid rail include a carbon mass fraction of 0.90% to 1.20%, a silicon mass fraction of 0.10% to 1.00%, a manganese mass fraction of 0.60% to 1.50%, a phosphorus mass fraction of no more than 0.020%, a chromium mass fraction of no more than 0.3%, and a vanadium mass fraction of no more than 0.01%.
  • the minimum tensile strength of the rail is 1300MPa, and the minimum hardness of the rail head is 400HB.
  • the main function of the above-mentioned pre-flash stage is to make the cross-section of the rail to be welded flat and clean through flash blasting, providing relatively uniform and flat favorable conditions and basic heat for subsequent flash.
  • it is mainly controlled by seven variables, namely high voltage time, high voltage, current setting value 1, current setting value 2, current setting value 3, pre-flash distance, and flash speed.
  • the high voltage in the pre-flash stage is 370V ⁇ 440V and the voltage time is 45s ⁇ 65s; the current value in the pre-flash stage is divided into three stages of setting values, current setting value 1 is 180A ⁇ 250A, current setting value 2 is 200A ⁇ 270A, and current setting value 3 is 220A ⁇ 300A; the pre-flash distance is 2mm ⁇ 10mm, and the flash speed is 0.1mm/s ⁇ 0.6mm/s.
  • the main function of the above-mentioned flash stage is to continue to flash evenly and continuously on the basis of the heat accumulated in the previous pre-flash, and to continuously heat the rails by using the heat generated by the blasting of the lintel, so as to form a certain temperature gradient in the longitudinal direction of the rails, heat the end faces of the rails to a sufficient temperature and lay the foundation for accelerating the burning process.
  • six variables are mainly controlled, namely, low voltage time, low voltage, current setting value 1, current setting value 2, current setting value 3, and flash speed.
  • the low voltage in the flash stage is 320V ⁇ 390V and the voltage time is 80s ⁇ 140s; the current value in the flash stage is divided into three stages of setting values, current setting value 1 is 180A ⁇ 250A, current setting value 2 is 200A ⁇ 270A, and current setting value 3 is 220A ⁇ 300A; the flash speed is 0.1mm/s ⁇ 0.6mm/s.
  • the main function of the above-mentioned accelerated burning stage is to form a protective atmosphere in the entire welding area to prevent end face oxidation, and finally form a suitable temperature field distribution to provide conditions for top forging.
  • it is mainly controlled by five variables, namely, accelerated burning voltage, current setting value 1, current setting value 2, current setting value 3, and acceleration speed.
  • the accelerated burning voltage in the accelerated burning stage is 380V ⁇ 450V, and the current value in the accelerated burning stage is divided into three stages of setting values, current setting value 1 is 180A ⁇ 250A, current setting value 2 is 200A ⁇ 270A, and current setting value 3 is 220A ⁇ 300A; acceleration The speed is 0.5mm/s ⁇ 2.0mm/s.
  • the charged upsetting time of the upsetting stage is 0.1s to 2.0s, the upsetting timing is 1.0s to 3.0s, and the upsetting amount is 5.0mm to 18.0mm.
  • the main function of the forging stage is to continuously apply load to the rail joint during the metal crystallization process of the joint after the rail top forging to enhance the joint bonding strength.
  • the rail consumption in the forging stage is 2.0mm ⁇ 4.0mm
  • the forging time is 1.5s ⁇ 3.0s
  • the average speed is 0.60mm/s ⁇ 2.60mm/s
  • the forging pressure is 60t ⁇ 80t.
  • the method for treating the joint after the flash welding is characterized in that the joint does not need to be treated after welding, and the joint is directly placed in the air to naturally cool to room temperature.
  • the test material of this embodiment is a pearlite rail with a profile of 60E1 as specified in the BS EN 13674-1 standard.
  • the measured carbon mass fraction of the rail entity chemical composition is 0.75%. Welding is performed using the welding method in the patent of the present invention.
  • the high voltage time in the pre-flash stage is 45s, the high voltage is 370V, the current setting value 1 is 180A, the current setting value 2 is 200A, the current setting value 3 is 220A, the pre-flash distance is 2mm, and the flash speed is 0.1mm/s;
  • the low voltage time in the flash stage is 80s, the low voltage is 320V, the current setting value 1 is 180A, the current setting value 2 is 200A, the current setting value 3 is 220A, and the flash speed is 0.1mm/s ;
  • the accelerated burning voltage in the accelerated burning stage is 380V, the current setting value 1 is 180A, the current setting value 2 is 200A, the current setting value 3 is 220A, and the acceleration speed is 0.5mm/s;
  • the charged upsetting time in the upsetting stage is 0.1s, the upsetting time is 1.0s, and the upsetting amount is 5.0mm;
  • the rail consumption in the forging stage is 2.0mm, the forging time is 1.5s, the average speed is 0.
  • the test material of this embodiment is a pearlite rail with a profile of 60kg specified in the AS 1085-1 standard.
  • the measured carbon mass fraction of the rail entity chemical composition is 0.65%.
  • the welding method of the present invention is used for welding.
  • the high voltage time of the pre-flash stage is 56s, the high voltage is 400V, the current setting value 1 is 220A, the current setting value 2 is 240A, the current setting value 3 is 260A, the pre-flash distance is 6mm,
  • the flash speed is 0.3mm/s;
  • the low voltage time in the flash stage is 110s, the low voltage is 350V, the current setting value 1 is 220A, the current setting value 2 is 240A, the current setting value 3 is 260A, and the flash speed is 0.3mm/s;
  • the accelerated burning voltage in the accelerated burning stage is 405V, the current setting value 1 is 220A, the current setting value 2 is 240A, the current setting value 3 is 260A, and the acceleration speed is 1.1mm
  • the test material of this embodiment is a pearlite rail with a profile of 115RE specified in the AREMA standard.
  • the measured carbon mass fraction of the rail entity chemical composition is 0.81%. Welding is performed using the welding method in the patent of the present invention.
  • the high-voltage time in the pre-flash stage is 53s, the high voltage is 390V, the current setting value 1 is 200A, the current setting value 2 is 230A, the current setting value 3 is 250A, the pre-flash distance is 5mm, and the flash speed is 0.2mm/s;
  • the low-voltage time in the flash stage is 100s, the low voltage is 345V, the current setting value 1 is 200A, the current setting value 2 is 230A, the current setting value 3 is 250A, and the flash speed is 0.2mm/s ;
  • the accelerated burning voltage in the accelerated burning stage is 400V, the current setting value 1 is 200A, the current setting value 2 is 230A, the current setting value 3 is 250A, and the acceleration speed
  • the test material of this embodiment is a pearlite rail with a profile of 136RE specified in the AREMA standard.
  • the measured carbon mass fraction of the rail entity chemical composition is 0.78%. Welding is performed using the welding method in the patent of the present invention.
  • the high-voltage time in the pre-flash stage is 61s, the high voltage is 420V, the current setting value 1 is 230A, the current setting value 2 is 250A, the current setting value 3 is 295A, the pre-flash distance is 8mm, and the flash speed is 0.5mm/s;
  • the low-voltage time in the flash stage is 135s, the low voltage is 380V, the current setting value 1 is 230A, the current setting value 2 is 250A, the current setting value 3 is 295A, and the flash speed is
  • the acceleration voltage of the accelerated burning stage is 430V, the current setting value 1 is 230A, the current setting value 2 is 250A, the current setting value 3 is 295A, and the acceleration speed is 1.7
  • the test material of this embodiment is a hypereutectoid rail with a profile of 136RE specified in the AREMA standard.
  • the measured carbon mass fraction of the rail entity chemical composition is 0.95%. Welding is performed using the welding method in the patent of the present invention.
  • the high-voltage time in the pre-flash stage is 58s, the high voltage is 410V, the current setting value 1 is 220A, the current setting value 2 is 260A, the current setting value 3 is 285A, the pre-flash distance is 7mm, and the flash speed is 0.4mm/s;
  • the low-voltage time in the flash stage is 120s, the low voltage is 371V, the current setting value 1 is 220A, the current setting value 2 is 260A, the current setting value 3 is 285A, and the flash speed is 0.4mm/s ;
  • the accelerated burning voltage in the accelerated burning stage is 425V, the current setting value 1 is 220A, the current setting value 2 is 260A, the current setting value 3 is 285A, and the acceleration speed is 1.5mm/s;
  • the charged upsetting time in the upsetting stage is 1.5s, the upsetting time is 2.0s, and the upsetting amount is 13.0mm;
  • the rail consumption in the forging stage is 3.5mm, the forging time
  • the test material of this embodiment is a hypereutectoid rail with a profile of 136RE specified in the AREMA standard.
  • the measured carbon mass fraction of the rail entity chemical composition is 1.01%. Welding is performed using the welding method in the patent of the present invention.
  • the high voltage time in the pre-flash stage is 65s, the high voltage is 440V, the current setting value 1 is 250A, the current setting value 2 is 270A, the current setting value 3 is 300A, the pre-flash distance is 10mm, and the flash speed is 0.6mm/s;
  • the low voltage time in the flash stage is 140s, the low voltage is 390V, the current setting value 1 is 250A, the current setting value 2 is 270A, the current setting value 3 is 300A, and the flash speed is 0.6mm/s;
  • the accelerated burning voltage in the accelerated burning stage is 450V, the current setting value 1 is 250A, the current setting value 2 is 270A, the current setting value 3 is 300A, and the acceleration speed is 2.0mm/s;
  • the top forging The live upsetting time of the stage is 2.0s, the upsetting time is 3.0s, the upsetting amount is 18.0mm; the rail consumption in the forging stage is 4.0mm, the forging time is 3.0s, the average speed is 2.60mm
  • test material of this comparative example is a hypereutectoid rail of 136RE profile specified in the AREMA standard.
  • the actual carbon mass fraction of the rail entity chemical composition is 1.01%.
  • the welding method in the patent of the present invention is not used for welding.
  • the high voltage time of the pre-flash stage is 65s, the high voltage is 445V, the current setting value 1 is 240A, the current setting value 2 is 260A, the current setting value 3 is 275A, the pre-flash distance is 9.5mm, and the flash speed is 0.55mm/s;
  • the low voltage time of the flash stage is 138s, the low voltage is 385V, the current setting value 1 is 240A, the current setting value 2 is 260A, the current setting value 3 is 275A, and the flash speed is 0.6mm/s;
  • the accelerated burning voltage of the accelerated burning stage is 447V, the current setting value 1 is 240A, the current setting value 2 is 260A, the current setting value 3 is 275A, and the acceleration speed is 2.0mm/s;
  • the charged upsetting time of the upsetting stage is 2.0s, the upsetting timing is 2.7s, and the upsetting amount is 16.8mm; there is no forging stage.
  • the static bending test uses a three-point or four-point support method to apply load to the rail joint at a certain loading rate until the load reaches the standard value and the maximum deflection is greater than the standard value.
  • the static bending performance of the joint is judged to be qualified.
  • Different rail types correspond to different load and deflection values.
  • the static bending load mainly reflects the bonding strength, appearance and internal defect indicators of the joint, and the deflection mainly reflects the strength and toughness indicators of the joint.
  • the joint will break before the load value specified in the standard is reached due to defects such as gray spots, lack of fusion or overburning, or the joint may be too hard or too soft due to improper matching of the heat input and upsetting amount of the joint, or improper post-weld treatment methods, so that the joint deflection does not meet the standard requirements.
  • the maximum deflection of the rail flash welded joint of Example 1 at the three-point static bending load of 2000 kN was 23.5 mm, and no fracture occurred;
  • the maximum deflection of the rail flash welded joint of Example 2 at the three-point static bending load of 2200 kN was 27.4 mm, and no fracture occurred;
  • the maximum deflection of the rail flash welded joint of Example 3 at the three-point static bending load of 2500 kN was 26.2 mm, and no fracture occurred;
  • the maximum deflection of the three-point static bending of the rail flash welded joint of Example 4 was 20.1 mm when the load was 2200 kN, and no fracture occurred;
  • the maximum deflection of the three-point static bending of the rail flash welded joint of Example 5 was 23.4 mm when the load was 2640 kN, and no fracture occurred;
  • the maximum deflection of the three-point static bending of the rail flash welded joint of Example 6 was 21.2 mm when the load was 2610
  • the comparative example did not use the welding method of the present invention for welding. It can be seen that the maximum deflection of the rail flash weld joint at the three-point static bending load was only 1557 kN, and the rail broke. The performance gap between the rails welded by the method of Examples 1-6 is large.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
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  • Machines For Laying And Maintaining Railways (AREA)

Abstract

Disclosed in the present invention is a method for improving the bonding strength of a rail flash-butt welded joint. In the method, a welding process is implemented using a mobile flash-butt welding machine; the welding process comprises pre-flash, flash, accelerated sintering, upset forging, and forging; and after completion of the welding process, a joint is naturally cooled to room temperature in the air, wherein the amount of upset forging during the upset forging stage is 5.0 mm to 18.0 mm, and the forging pressure during the forging stage is 60 t to 80 t. Further disclosed in the present invention is a rail obtained by welding using the method. By means of the method for improving the bonding strength of a rail flash-butt welded joint provided by the present invention, the rail welded by this method has no flat spots, unwelded areas, overburn or other weld defects at rail welds, and has a rough rail fracture, thereby effectively ensuring that the static bending performance of the rail flash-butt welded joint is greatly improved.

Description

一种提升钢轨闪光对焊接头的结合强度的方法A method for improving the bonding strength of rail flash butt welding joints 技术领域Technical Field
本发明属于钢轨焊接技术领域，尤其涉及一种提升钢轨闪光对焊接头的结合强度的方法。The invention belongs to the technical field of rail welding, and in particular relates to a method for improving the bonding strength of a rail flash butt welding joint.
背景技术Background technique
随着全球钢轨线路向高速及重载方向的发展，钢轨焊接也越来越成为关注的焦点。目前国内外主流的钢轨闪光对焊是通过导电电极等夹紧装置将两侧钢轨夹紧，通电后使钢轨端面接触，导通电流在接触点处产生电阻热，使得接触点迅速熔化，形成闪光并伴随强烈的飞溅，经过一定的闪光留量后施加一定的顶锻力，从而使钢轨在高温下重新结晶成形的一种焊接方法。主要分为固定式闪光焊和移动式闪光焊两种。移动式闪光焊接，因其设备小、移动方便等特点，常用于铺轨现场施工焊接，而钢轨固定式闪光焊通常将焊接设备固定与厂房内，故通常也被称为厂焊或基地焊接。除应用场景外，两者最大的不同在于加热钢轨的方式。移动式闪光焊是通过间歇脉动闪光***或者连续不断的闪光***加热钢轨，故移动式闪光焊可以分为脉动式闪光和连续式闪光两种。固定式闪光焊通常是通过直接将钢轨进行短路，利用电阻热的方式将钢轨进行加热，加热过程并不(或少量)伴随闪光，通常又被称为短路预热闪光焊。As the global rail lines develop towards high speed and heavy load, rail welding has become more and more the focus of attention. At present, the mainstream rail flash welding at home and abroad is to clamp the rails on both sides through clamping devices such as conductive electrodes, make the end faces of the rails contact after power is turned on, and the current is turned on to generate resistance heat at the contact point, so that the contact point melts rapidly, forming flash and accompanied by strong spatter. After a certain amount of flash is left, a certain upsetting force is applied to make the rail recrystallize and form at high temperature. It is mainly divided into two types: fixed flash welding and mobile flash welding. Mobile flash welding, due to its small equipment and easy mobility, is often used for welding on the track laying site, while fixed rail flash welding usually fixes the welding equipment in the factory, so it is also usually called factory welding or base welding. In addition to the application scenario, the biggest difference between the two is the way to heat the rails. Mobile flash welding heats the rails through intermittent pulsating flash blasting or continuous flash blasting, so mobile flash welding can be divided into pulsating flash and continuous flash. Fixed flash welding is usually done by directly short-circuiting the rails and heating them using resistance heat. The heating process is not (or only slightly) accompanied by flash, and is often referred to as short-circuit preheating flash welding.
目前，国际上主流的钢轨闪光焊接标准主要有中国铁道行业标准系列标准TB/T 1632.2-2014《钢轨焊接第2部分：闪光焊接》、美国铁路工程协会手册AMERICAN RARILWAY ENGINEERING AND MAINTENANCE-OF-WAY ASSOCIATION(AREMA)、欧标BS EN 14587-3:2012,Rail way applications-Track-Flash butt welding of rails.Part 3:Welding in association with crossing construction以及澳标AS1085.20-2012, Railway track material Part20：Welding of steel rail。所有现行适用于珠光体钢轨闪光焊接标准和企业技术条件中，对钢轨闪光焊接头显微组织均做出了具体的规定。TB/T 1632.2中规定钢轨接头焊缝和热影响区的显微组织应为珠光体，可出现少量的铁素体，不应有马氏体或贝氏体等有害组织；AMEMA中规定，钢轨接头焊缝和热影响区希望为100％的珠光体组织，一旦接头产生了未回火的马氏体组织，会影响静弯试验的结果；欧标BS EN 14587标准中规定，采用光学显微镜在100×的放大倍数下进行观察，不能出现具有脆化迹象的针状碳化物及晶间连续网状的碳化物，允许出现颗粒状的马氏体组织；澳标AS1085.20标准中规定，钢轨接头显微组织应为基本上没有晶间渗碳体和未回火马氏体的珠光体组织，如果能满足其他试验的要求，允许存在少量马氏体。钢轨闪光焊接头纵断面硬度，即沿钢轨纵向轧制方向将钢轨对剖后，检验接头行车面以下3～5mm、接头熔合线两侧超过热影响区宽度20mm范围内的硬度值，有的标准采用洛氏硬度，有的采用维氏硬度，或者两者均可。钢轨焊接接头的硬度是影响高速铁路轨道平顺性的重要因素，只有接头与母材硬度水平相当，才能保证接头在服役期内与线路钢轨具有一致的耐磨性。目前存在的问题是接头无论是焊接状态还是热处理状态都有软化区，在服役期间会出现马鞍形磨耗，导致线路平顺性变坏。正确的焊后处理工艺能改善接头组织，降低软化程度，尽可能地满足接头耐磨性能要求。钢轨闪光焊接头静弯试验是目前国内外运用最广泛的钢轨接头整体性能评价方法，所有钢轨接头检验标准中都有规定。主要包括两项指标，即载荷和挠度。静弯试验是采用三点或四点支撑的方法，以一定的加载速率，向钢轨接头施加载荷，直到载荷达到标准规定值不断，并且最大挠度大于标准规定值，则判定接头静弯性能合格，不同的轨型对应不同的载荷与挠度值。欧洲标准BS EN14587-2:2009要求接头最低荷载和挠度分别不小于1600KN和20mm(60kg/m钢轨，轨头受压)。欧洲标准BS EN14587-2:2009要求接头轨底最小应力为900MPa，经折算后的最低荷载和挠度分别不小于1670KN和20mm(60kg/m钢轨，轨头受压)。我国对于静弯标准要求是破断载荷不小于1450kN(60kg/m，轨头受压)， 对挠度不作要求。静弯载荷主要体现了接头的结合强度、接头外观以及内部缺陷指标，挠度主要体现了接头强韧性指标。若接头焊接工艺不良，极有可能因为灰斑、未熔合或者过烧等缺陷导致接头在未达到标准规定的载荷值前断裂，或者因为接头热输入和顶锻量匹配不当、焊后处理方法不当导致接头偏硬或偏软，使接头挠度达不到标准要求。At present, the mainstream international standards for rail flash welding mainly include China Railway Industry Standard Series Standard TB/T 1632.2-2014 "Rail Welding Part 2: Flash Welding", American Railway Engineering Association Manual AMERICAN RARILWAY ENGINEERING AND MAINTENANCE-OF-WAY ASSOCIATION (AREMA), European Standard BS EN 14587-3:2012, Rail way applications-Track-Flash butt welding of rails. Part 3: Welding in association with crossing construction and Australian Standard AS1085.20-2012, Railway track material Part 20: Welding of steel rail. All current standards and enterprise technical requirements applicable to flash welding of pearlite rails have made specific provisions on the microstructure of rail flash welds. TB/T 1632.2 stipulates that the microstructure of the rail joint weld and heat-affected zone should be pearlite, a small amount of ferrite may appear, and there should be no harmful structures such as martensite or bainite; AMEMA stipulates that the rail joint weld and heat-affected zone are expected to be 100% pearlite. Once the joint produces untempered martensite, it will affect the results of the static bending test; European standard BS EN 14587 stipulates that when observing with an optical microscope at a magnification of 100×, no needle-shaped carbides with signs of embrittlement and continuous intergranular carbides should appear, and granular martensite is allowed; Australian standard AS1085.20 stipulates that the microstructure of the rail joint should be pearlite with basically no intergranular cementite and untempered martensite. If it meets the requirements of other tests, a small amount of martensite is allowed. The hardness of the longitudinal section of the rail flash weld joint, that is, after the rail is cut in half along the longitudinal rolling direction of the rail, the hardness value within the range of 3 to 5 mm below the running surface of the joint and 20 mm on both sides of the joint fusion line exceeding the width of the heat affected zone, is tested. Some standards use Rockwell hardness, some use Vickers hardness, or both. The hardness of the rail weld joint is an important factor affecting the smoothness of the high-speed railway track. Only when the hardness level of the joint is equivalent to that of the parent material can the joint have consistent wear resistance with the line rail during the service life. The current problem is that the joint has a softening zone in both the welding state and the heat treatment state, and saddle-shaped wear will occur during service, resulting in deterioration of the line smoothness. The correct post-weld treatment process can improve the joint organization, reduce the softening degree, and meet the wear resistance requirements of the joint as much as possible. The static bending test of the rail flash weld joint is the most widely used overall performance evaluation method for rail joints at home and abroad, and is stipulated in all rail joint inspection standards. It mainly includes two indicators, namely load and deflection. The static bending test uses a three-point or four-point support method to apply load to the rail joint at a certain loading rate until the load reaches the standard value and the maximum deflection is greater than the standard value. The static bending performance of the joint is judged to be qualified. Different rail types correspond to different load and deflection values. The European standard BS EN14587-2:2009 requires that the minimum load and deflection of the joint be no less than 1600KN and 20mm respectively (60kg/m rail, rail head under pressure). The European standard BS EN14587-2:2009 requires that the minimum stress at the bottom of the joint rail be 900MPa, and the converted minimum load and deflection are no less than 1670KN and 20mm respectively (60kg/m rail, rail head under pressure). my country's static bending standard requirements are that the breaking load is not less than 1450kN (60kg/m, rail head under pressure), There is no requirement for deflection. The static bending load mainly reflects the joint strength, joint appearance and internal defect indicators, and the deflection mainly reflects the joint toughness indicator. If the joint welding process is poor, it is very likely that the joint will break before reaching the load value specified in the standard due to defects such as gray spots, lack of fusion or overburning, or because the joint heat input and upsetting amount are not matched properly, or the post-weld treatment method is improper, resulting in the joint being too hard or too soft, so that the joint deflection does not meet the standard requirements.
综上所述，铁路工程领域亟需一种提升钢轨闪光对焊接头结合强度的方法，以能够有效的确保钢轨闪光焊接头静弯性能得到大幅提升。In summary, the railway engineering field urgently needs a method to improve the bonding strength of rail flash butt welded joints, so as to effectively ensure that the static bending performance of rail flash welded joints is greatly improved.
发明内容Summary of the invention
基于此，为了弥补现有钢轨焊接技术的不足，提供一种耐内部损伤性珠光体钢轨或高强韧性珠光体钢轨的焊接方法，该方法能够有效缓减焊接接头微观组织中异常缺陷的产生，从而保证铁路运行安全。Based on this, in order to make up for the shortcomings of existing rail welding technology, a welding method for internal damage resistant pearlite rails or high strength and toughness pearlite rails is provided, which can effectively reduce the generation of abnormal defects in the microstructure of the welded joints, thereby ensuring the safety of railway operation.
为了实现上述目的，采用以下技术方案：In order to achieve the above purpose, the following technical solutions are adopted:
本发明提供一种提升钢轨闪光对焊接头的结合强度的方法，所述方法采用移动式闪光焊机实现焊接过程，所述焊接过程包括预闪光、闪光、加速烧化、顶锻及锻造；在所述焊接过程结束后，将接头至于空气中自然冷却至室温；The present invention provides a method for improving the bonding strength of a rail flash butt weld joint, wherein the method uses a mobile flash welder to implement a welding process, wherein the welding process includes pre-flash, flash, accelerated burning, upsetting and forging; after the welding process is completed, the joint is naturally cooled in the air to room temperature;
其中，顶锻阶段的顶锻量为5.0mm～18.0mm；锻造阶段的锻造压力为60t～80t。Among them, the upsetting amount in the upsetting stage is 5.0mm~18.0mm; the forging pressure in the forging stage is 60t~80t.
进一步地，所述钢轨选自碳的质量分数处于0.60wt％～0.90wt％的珠光体钢轨以及碳的质量分数处于0.90wt％～1.20wt％的过共析钢轨。Furthermore, the steel rail is selected from a pearlite steel rail having a carbon mass fraction of 0.60wt% to 0.90wt% and a hypereutectoid steel rail having a carbon mass fraction of 0.90wt% to 1.20wt%.
进一步地，所述珠光体钢轨包括以下组分：碳的质量分数处于0.60％～0.90％、硅的质量分数处于0.10％～1.00％、锰的质量分数处于0.60％～1.50％、磷和硫的质量分数均小于0.020％，铬的质量分数小于0.3％以及钒的质量分数小于0.01％。Furthermore, the pearlite rail comprises the following components: carbon mass fraction is 0.60% to 0.90%, silicon mass fraction is 0.10% to 1.00%, manganese mass fraction is 0.60% to 1.50%, phosphorus and sulfur mass fractions are both less than 0.020%, chromium mass fraction is less than 0.3% and vanadium mass fraction is less than 0.01%.
进一步地，所述过共析钢轨包括以下组分：碳的质量分数处于0.90％～1.20％、硅的质量分数处于0.10％～1.00％、锰的质量分数处于0.60％～1.50％、 磷和硫的质量分数均小于0.020％，铬的质量分数小于0.3％以及钒的质量分数小于0.01％。Furthermore, the hypereutectoid rail comprises the following components: the mass fraction of carbon is 0.90% to 1.20%, the mass fraction of silicon is 0.10% to 1.00%, the mass fraction of manganese is 0.60% to 1.50%, The mass fractions of phosphorus and sulfur are both less than 0.020%, the mass fraction of chromium is less than 0.3%, and the mass fraction of vanadium is less than 0.01%.
进一步地，顶锻阶段的带电顶锻时间为0.1s～2.0s，顶锻计时为1.0s～3.0s。Furthermore, the charged upsetting time in the upsetting stage is 0.1s to 2.0s, and the upsetting timing is 1.0s to 3.0s.
进一步地，锻造阶段的钢轨消耗量为2.0mm～4.0mm，锻造时间为1.5s～3.0s，平均速度为0.60mm/s～2.60mm/s。Furthermore, the rail consumption in the forging stage is 2.0 mm to 4.0 mm, the forging time is 1.5 s to 3.0 s, and the average speed is 0.60 mm/s to 2.60 mm/s.
进一步地，预闪光阶段的电压为370V～440V且电压时间为45s～65s，电流值为180A～300A，预闪光距离为2mm～10mm，闪光速度为0.1mm/s～0.6mm/s。Furthermore, the voltage of the pre-flash stage is 370V to 440V and the voltage time is 45s to 65s, the current value is 180A to 300A, the pre-flash distance is 2mm to 10mm, and the flash speed is 0.1mm/s to 0.6mm/s.
更进一步地，预闪光阶段的电流值分为三个阶段的设定值，电流设定值1为180A～250A、电流设定值2为200A～270A、电流设定值3为220A～300A。Furthermore, the current value in the pre-flash stage is divided into three stages of setting values, current setting value 1 is 180A~250A, current setting value 2 is 200A~270A, and current setting value 3 is 220A~300A.
进一步地，闪光阶段的电压为320V～390V且电压时间为80s～140s，电流值为180A～300A，闪光速度为0.1mm/s～0.6mm/s。Furthermore, the voltage in the flashing stage is 320V to 390V and the voltage time is 80s to 140s, the current value is 180A to 300A, and the flashing speed is 0.1mm/s to 0.6mm/s.
更进一步地，闪光阶段的电流值分为三个阶段的设定值，电流设定值1为180A～250A、电流设定值2为200A～270A、电流设定值3为220A～300A。Furthermore, the current value in the flash stage is divided into three stages of setting values, current setting value 1 is 180A~250A, current setting value 2 is 200A~270A, and current setting value 3 is 220A~300A.
进一步地，加速烧化阶段的电压为380V～450V，电流为180A～300A，加速速度为0.5mm/s～2.0mm/s。Furthermore, the voltage of the accelerated burning stage is 380V to 450V, the current is 180A to 300A, and the acceleration speed is 0.5mm/s to 2.0mm/s.
更进一步地，加速烧化阶段的电流值分为三个阶段的设定值，电流设定值1为180A～250A、电流设定值2为200A～270A、电流设定值3为220A～300A。Furthermore, the current value in the accelerated burning stage is divided into three stages of setting values, current setting value 1 is 180A~250A, current setting value 2 is 200A~270A, and current setting value 3 is 220A~300A.
本发明还提供一种由上所述的方法焊接得到的钢轨。The present invention also provides a steel rail welded by the above method.
本发明具有以下有益技术效果：The present invention has the following beneficial technical effects:
本发明主要针对碳的质量分数处于0.60％～0.90％的珠光体钢轨以及碳的质量分数处于0.90％～1.20％的过共析钢轨，提供一种提升钢轨闪光对焊接头结合强度的方法。采用该方法焊接的钢轨焊缝无灰斑、未焊合及过烧 等焊接缺陷，钢轨断口粗糙，能够有效的确保钢轨闪光焊接头静弯性能得到大幅提升。The present invention mainly provides a method for improving the bonding strength of rail flash butt welding joints for pearlite rails with a carbon mass fraction of 0.60% to 0.90% and hypereutectoid rails with a carbon mass fraction of 0.90% to 1.20%. The rail welds welded by the method have no gray spots, unwelded or overburned Welding defects such as rough rail fracture can be effectively ensured to greatly improve the static bending performance of the rail flash welded joint.
本发明的提升钢轨闪光对焊接头结合强度的方法，将中前期的加热阶段，通过与现有技术中的脉动闪光不同的闪光方法进行钢轨加热，同时去掉现有技术中的保压阶段，改为锻造阶段。本发明的提升钢轨闪光对焊接头结合强度的方法的锻造阶段采用液压流量控制，并伴随有位移的变化，通过新增的锻造，接头结合强度大幅提升。The method for improving the bonding strength of rail flash butt welding joints of the present invention heats the rails in the early and middle heating stages by a flash method different from the pulsating flash in the prior art, and at the same time removes the pressure holding stage in the prior art and replaces it with a forging stage. The forging stage of the method for improving the bonding strength of rail flash butt welding joints of the present invention adopts hydraulic flow control, accompanied by displacement changes, and the joint bonding strength is greatly improved through the newly added forging.
具体实施方式Detailed ways
为使本发明的目的、技术方案和优点更加清楚明白，以下结合具体实施例，并参照附图，对本发明实施例进一步详细说明。In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.
本发明中，所述“接头”、“焊接头”为经焊接后得到的包含焊缝和/或热影响区在内的长度为80-120mm范围的区域，该区域的中心为钢轨焊缝。本发明中，所述“室温”为5-40℃范围的温度。In the present invention, the "joint" or "weld joint" is an area with a length of 80-120 mm including the weld and/or heat-affected zone obtained after welding, and the center of the area is the rail weld. In the present invention, the "room temperature" is a temperature in the range of 5-40°C.
本发明的实施例主要针对碳的质量分数处于0.60％～0.90％的珠光体钢轨以及碳的质量分数处于0.90％～1.20％的过共析钢轨，提供一种提升上述类型的钢轨闪光对焊接头的结合强度的方法。采用该方法焊接的钢轨焊缝无灰斑、未焊合及过烧等焊接缺陷，钢轨断口粗糙，能够有效的确保钢轨闪光对焊接头静弯性能得到大幅提升。The embodiments of the present invention mainly provide a method for improving the bonding strength of the flash butt welded joints of the pearlite rails with a carbon mass fraction of 0.60% to 0.90% and the hypereutectoid rails with a carbon mass fraction of 0.90% to 1.20%. The rail welds welded by the method have no welding defects such as gray spots, unwelded and over-burned, and the rail fracture is rough, which can effectively ensure that the static bending performance of the flash butt welded joints of the rails is greatly improved.
为了实现上述目的，上述提升钢轨闪光对焊接头的结合强度的方法采用钢轨移动式闪光焊机实现，整个焊接过程包括预闪光、闪光、加速烧化、顶锻及锻造等5个主要阶段。在闪光焊接结束后，将接头至于空气中自然冷却至室温。In order to achieve the above purpose, the above method for improving the bonding strength of rail flash butt welding joints is implemented by using a rail mobile flash welding machine. The entire welding process includes five main stages: pre-flash, flash, accelerated burning, top forging and forging. After the flash welding is completed, the joint is naturally cooled to room temperature in the air.
上述的碳的质量分数处于0.60％～0.90％的珠光体钢轨。珠光体钢轨的主要化学成分中碳的质量分数处于0.60％～0.90％、硅的质量分数处于0.10％～1.00％、锰的质量分数处于0.60％～1.50％、磷和硫的质量分数均不超过0.020％，铬的质量分数不超过0.3％以及钒的质量分数不超过0.01％。 珠光体钢轨的最小抗拉强度为800MPa，轨头最小硬度为250HB。The pearlite rail has a carbon mass fraction of 0.60% to 0.90%. The main chemical components of the pearlite rail include carbon mass fraction of 0.60% to 0.90%, silicon mass fraction of 0.10% to 1.00%, manganese mass fraction of 0.60% to 1.50%, phosphorus and sulfur mass fractions not exceeding 0.020%, chromium mass fraction not exceeding 0.3% and vanadium mass fraction not exceeding 0.01%. The minimum tensile strength of pearlite rail is 800MPa and the minimum hardness of rail head is 250HB.
上述的碳的质量分数处于0.90％～1.20％的过共析钢轨。过共析钢轨的主要化学成分中碳的质量分数处于0.90％～1.20％、硅的质量分数处于0.10％～1.00％、锰的质量分数处于0.60％～1.50％、磷和硫的质量分数均不超过0.020％，铬的质量分数不超过0.3％以及钒的质量分数不超过0.01％。钢轨的最小抗拉强度为1300MPa，轨头最小硬度为400HB。The above-mentioned hypereutectoid rail has a carbon mass fraction of 0.90% to 1.20%. The main chemical components of the hypereutectoid rail include a carbon mass fraction of 0.90% to 1.20%, a silicon mass fraction of 0.10% to 1.00%, a manganese mass fraction of 0.60% to 1.50%, a phosphorus mass fraction of no more than 0.020%, a chromium mass fraction of no more than 0.3%, and a vanadium mass fraction of no more than 0.01%. The minimum tensile strength of the rail is 1300MPa, and the minimum hardness of the rail head is 400HB.
上述的预闪光阶段的主要作用是通过闪光***使得钢轨待焊截面平整清洁，为后续的闪光提供相对均匀平整的有利条件和基础热量。为实现上述目的，主要通过高压时间、高电压、电流设定值1、电流设定值2、电流设定值3、预闪光距离、闪光速度等7个变量控制。预闪光阶段的高电压为370V～440V且电压时间为45s～65s；预闪光阶段的电流值分为三个阶段的设定值，电流设定值1为180A～250A、电流设定值2为200A～270A、电流设定值3为220A～300A；预闪光距离为2mm～10mm、闪光速度为0.1mm/s～0.6mm/s。The main function of the above-mentioned pre-flash stage is to make the cross-section of the rail to be welded flat and clean through flash blasting, providing relatively uniform and flat favorable conditions and basic heat for subsequent flash. To achieve the above purpose, it is mainly controlled by seven variables, namely high voltage time, high voltage, current setting value 1, current setting value 2, current setting value 3, pre-flash distance, and flash speed. The high voltage in the pre-flash stage is 370V~440V and the voltage time is 45s~65s; the current value in the pre-flash stage is divided into three stages of setting values, current setting value 1 is 180A~250A, current setting value 2 is 200A~270A, and current setting value 3 is 220A~300A; the pre-flash distance is 2mm~10mm, and the flash speed is 0.1mm/s~0.6mm/s.
上述的闪光阶段主要作用是在前期预闪积累热量的基础上，继续连续不断地均匀闪光，利用过梁***产生的将钢轨持续加热，在钢轨纵向形成一定的温度梯度，将钢轨的端面加热到足够的温度并为加速烧化过程奠定条件。为实现上述目的，主要通过低压时间、低电压、电流设定值1、电流设定值2、电流设定值3、闪光速度等6个变量控制。，闪光阶段的低电压为320V～390V且电压时间为80s～140s；闪光阶段的电流值分为三个阶段的设定值，电流设定值1为180A～250A、电流设定值2为200A～270A、电流设定值3为220A～300A；闪光速度为0.1mm/s～0.6mm/s。The main function of the above-mentioned flash stage is to continue to flash evenly and continuously on the basis of the heat accumulated in the previous pre-flash, and to continuously heat the rails by using the heat generated by the blasting of the lintel, so as to form a certain temperature gradient in the longitudinal direction of the rails, heat the end faces of the rails to a sufficient temperature and lay the foundation for accelerating the burning process. To achieve the above purpose, six variables are mainly controlled, namely, low voltage time, low voltage, current setting value 1, current setting value 2, current setting value 3, and flash speed. The low voltage in the flash stage is 320V~390V and the voltage time is 80s~140s; the current value in the flash stage is divided into three stages of setting values, current setting value 1 is 180A~250A, current setting value 2 is 200A~270A, and current setting value 3 is 220A~300A; the flash speed is 0.1mm/s~0.6mm/s.
上述的加速烧化阶段主要作用是在整个焊接区域形成防止端面氧化的保护气氛，最终形成合适的温度场分布，为顶锻提供条件。为实现上述目的，主要通过加速烧化电压、电流设定值1、电流设定值2、电流设定值3、加速速度等5个变量控制。加速烧化阶段的加速烧化电压为380V～450V，加速烧化阶段的电流值分为三个阶段的设定值，电流设定值1为180A～250A、电流设定值2为200A～270A、电流设定值3为220A～300A；加速 速度为0.5mm/s～2.0mm/s。The main function of the above-mentioned accelerated burning stage is to form a protective atmosphere in the entire welding area to prevent end face oxidation, and finally form a suitable temperature field distribution to provide conditions for top forging. To achieve the above purpose, it is mainly controlled by five variables, namely, accelerated burning voltage, current setting value 1, current setting value 2, current setting value 3, and acceleration speed. The accelerated burning voltage in the accelerated burning stage is 380V~450V, and the current value in the accelerated burning stage is divided into three stages of setting values, current setting value 1 is 180A~250A, current setting value 2 is 200A~270A, and current setting value 3 is 220A~300A; acceleration The speed is 0.5mm/s～2.0mm/s.
上述的顶锻阶段的带电顶锻时间为0.1s～2.0s，顶锻计时为1.0s～3.0s，顶锻量为5.0mm～18.0mm。The charged upsetting time of the upsetting stage is 0.1s to 2.0s, the upsetting timing is 1.0s to 3.0s, and the upsetting amount is 5.0mm to 18.0mm.
上述的锻造阶段主要作用是在钢轨顶锻后的接头金属结晶过程中对钢轨接头持续施加载荷，增强接头结合强度。为实现上述目的，锻造阶段钢轨消耗量为2.0mm～4.0mm，锻造时间为1.5s～3.0s，平均速度为0.60mm/s～2.60mm/s，锻造压力为60t～80t。The main function of the forging stage is to continuously apply load to the rail joint during the metal crystallization process of the joint after the rail top forging to enhance the joint bonding strength. To achieve the above purpose, the rail consumption in the forging stage is 2.0mm~4.0mm, the forging time is 1.5s~3.0s, the average speed is 0.60mm/s~2.60mm/s, and the forging pressure is 60t~80t.
上述的闪光焊接结束后对接头的处理方法。其特征在于无需焊后的接头进行处理，直接将接头至于空气中自然冷却至室温。The method for treating the joint after the flash welding is characterized in that the joint does not need to be treated after welding, and the joint is directly placed in the air to naturally cool to room temperature.
实施例1Example 1
本实施例的试验材料为BS EN 13674-1标准中规定的60E1廓形的珠光体钢轨。钢轨实体化学成分实测碳质量分数为0.75％。采用本发明专利中焊接方法进行焊接。预闪光阶段的高压时间为45s、高电压为370V、电流设定值1为180A、电流设定值2为200A、电流设定值3为220A、预闪光距离为2mm、闪光速度为0.1mm/s；闪光阶段的低压时间为80s、低电压为320V、电流设定值1为180A、电流设定值2为200A、电流设定值3为220A、闪光速度为0.1mm/s；加速烧化阶段的加速烧化电压为380V、电流设定值1为180A、电流设定值2为200A、电流设定值3为220A、加速速度为0.5mm/s；顶锻阶段的带电顶锻时间为0.1s，顶锻计时为1.0s，顶锻量为5.0mm；锻造阶段钢轨消耗量为2.0mm，锻造时间为1.5s，平均速度为0.60mm/s，锻造压力为60t。本实施例中所述钢轨闪光焊接头三点静弯的载荷为2000kN时的最大挠度为23.5mm，未发生断裂，远超标准要求。The test material of this embodiment is a pearlite rail with a profile of 60E1 as specified in the BS EN 13674-1 standard. The measured carbon mass fraction of the rail entity chemical composition is 0.75%. Welding is performed using the welding method in the patent of the present invention. The high voltage time in the pre-flash stage is 45s, the high voltage is 370V, the current setting value 1 is 180A, the current setting value 2 is 200A, the current setting value 3 is 220A, the pre-flash distance is 2mm, and the flash speed is 0.1mm/s; the low voltage time in the flash stage is 80s, the low voltage is 320V, the current setting value 1 is 180A, the current setting value 2 is 200A, the current setting value 3 is 220A, and the flash speed is 0.1mm/s ; The accelerated burning voltage in the accelerated burning stage is 380V, the current setting value 1 is 180A, the current setting value 2 is 200A, the current setting value 3 is 220A, and the acceleration speed is 0.5mm/s; the charged upsetting time in the upsetting stage is 0.1s, the upsetting time is 1.0s, and the upsetting amount is 5.0mm; the rail consumption in the forging stage is 2.0mm, the forging time is 1.5s, the average speed is 0.60mm/s, and the forging pressure is 60t. The maximum deflection of the three-point static bending of the rail flash welded joint described in this embodiment is 23.5mm when the load is 2000kN, and no fracture occurs, which far exceeds the standard requirements.
实施例2Example 2
本实施例的试验材料为AS 1085-1标准中规定的60kg廓形的珠光体钢轨。钢轨实体化学成分实测碳质量分数为0.65％。采用本发明专利中焊接方法进行焊接。预闪光阶段的高压时间为56s、高电压为400V、电流设定值1为220A、电流设定值2为240A、电流设定值3为260A、预闪光距离为6mm、 闪光速度为0.3mm/s；闪光阶段的低压时间为110s、低电压为350V、电流设定值1为220A、电流设定值2为240A、电流设定值3为260A、闪光速度为0.3mm/s；加速烧化阶段的加速烧化电压为405V、电流设定值1为220A、电流设定值2为240A、电流设定值3为260A、加速速度为1.1mm/s；顶锻阶段的带电顶锻时间为0.5s，顶锻计时为2.0s，顶锻量为12.0mm；锻造阶段钢轨消耗量为3.8mm，锻造时间为2.0s，平均速度为1.90mm/s，锻造压力为70t。本实施例中所述钢轨闪光焊接头三点静弯的载荷为2200kN时的最大挠度为27.4mm，未发生断裂，远超标准要求。The test material of this embodiment is a pearlite rail with a profile of 60kg specified in the AS 1085-1 standard. The measured carbon mass fraction of the rail entity chemical composition is 0.65%. The welding method of the present invention is used for welding. The high voltage time of the pre-flash stage is 56s, the high voltage is 400V, the current setting value 1 is 220A, the current setting value 2 is 240A, the current setting value 3 is 260A, the pre-flash distance is 6mm, The flash speed is 0.3mm/s; the low voltage time in the flash stage is 110s, the low voltage is 350V, the current setting value 1 is 220A, the current setting value 2 is 240A, the current setting value 3 is 260A, and the flash speed is 0.3mm/s; the accelerated burning voltage in the accelerated burning stage is 405V, the current setting value 1 is 220A, the current setting value 2 is 240A, the current setting value 3 is 260A, and the acceleration speed is 1.1mm/s; the charged upsetting time in the upsetting stage is 0.5s, the upsetting timing is 2.0s, and the upsetting amount is 12.0mm; the rail consumption in the forging stage is 3.8mm, the forging time is 2.0s, the average speed is 1.90mm/s, and the forging pressure is 70t. The maximum deflection of the rail flash welding head described in this embodiment when the load of the three-point static bending is 2200kN is 27.4mm, and no fracture occurs, which far exceeds the standard requirements.
实施例3Example 3
本实施例的试验材料为AREMA标准中规定的115RE廓形的珠光体钢轨。钢轨实体化学成分实测碳质量分数为0.81％。采用本发明专利中焊接方法进行焊接。预闪光阶段的高压时间为53s、高电压为390V、电流设定值1为200A、电流设定值2为230A、电流设定值3为250A、预闪光距离为5mm、闪光速度为0.2mm/s；闪光阶段的低压时间为100s、低电压为345V、电流设定值1为200A、电流设定值2为230A、电流设定值3为250A、闪光速度为0.2mm/s；加速烧化阶段的加速烧化电压为400V、电流设定值1为200A、电流设定值2为230A、电流设定值3为250A、加速速度为0.9mm/s；顶锻阶段的带电顶锻时间为0.7s，顶锻计时为1.3s，顶锻量为10.0mm；锻造阶段钢轨消耗量为3.4mm，锻造时间为1.7s，平均速度为2.00mm/s，锻造压力为70t。本实施例中所述钢轨闪光焊接头三点静弯的载荷为2500kN时的最大挠度为26.2mm，未发生断裂，远超标准要求。The test material of this embodiment is a pearlite rail with a profile of 115RE specified in the AREMA standard. The measured carbon mass fraction of the rail entity chemical composition is 0.81%. Welding is performed using the welding method in the patent of the present invention. The high-voltage time in the pre-flash stage is 53s, the high voltage is 390V, the current setting value 1 is 200A, the current setting value 2 is 230A, the current setting value 3 is 250A, the pre-flash distance is 5mm, and the flash speed is 0.2mm/s; the low-voltage time in the flash stage is 100s, the low voltage is 345V, the current setting value 1 is 200A, the current setting value 2 is 230A, the current setting value 3 is 250A, and the flash speed is 0.2mm/s ; The accelerated burning voltage in the accelerated burning stage is 400V, the current setting value 1 is 200A, the current setting value 2 is 230A, the current setting value 3 is 250A, and the acceleration speed is 0.9mm/s; the charged upsetting time in the upsetting stage is 0.7s, the upsetting timing is 1.3s, and the upsetting amount is 10.0mm; the rail consumption in the forging stage is 3.4mm, the forging time is 1.7s, the average speed is 2.00mm/s, and the forging pressure is 70t. The maximum deflection of the three-point static bending of the rail flash welded joint described in this embodiment is 26.2mm when the load is 2500kN, and no fracture occurs, which far exceeds the standard requirements.
实施例4Example 4
本实施例的试验材料为AREMA标准中规定的136RE廓形的珠光体钢轨。钢轨实体化学成分实测碳质量分数为0.78％。采用本发明专利中焊接方法进行焊接。预闪光阶段的高压时间为61s、高电压为420V、电流设定值1为230A、电流设定值2为250A、电流设定值3为295A、预闪光距离为8mm、闪光速度为0.5mm/s；闪光阶段的低压时间为135s、低电压为380V、电流设定值1为230A、电流设定值2为250A、电流设定值3为295A、闪光速 度为0.5mm/s；加速烧化阶段的加速烧化电压为430V、电流设定值1为230A、电流设定值2为250A、电流设定值3为295A、加速速度为1.7mm/s；顶锻阶段的带电顶锻时间为1.2s，顶锻计时为2.4s，顶锻量为16.0mm；锻造阶段钢轨消耗量为2.3mm，锻造时间为1.5s，平均速度为1.53mm/s，锻造压力为60t。本实施例中所述钢轨闪光焊接头三点静弯的载荷为2200kN时的最大挠度为20.1mm，未发生断裂，远超标准要求。The test material of this embodiment is a pearlite rail with a profile of 136RE specified in the AREMA standard. The measured carbon mass fraction of the rail entity chemical composition is 0.78%. Welding is performed using the welding method in the patent of the present invention. The high-voltage time in the pre-flash stage is 61s, the high voltage is 420V, the current setting value 1 is 230A, the current setting value 2 is 250A, the current setting value 3 is 295A, the pre-flash distance is 8mm, and the flash speed is 0.5mm/s; the low-voltage time in the flash stage is 135s, the low voltage is 380V, the current setting value 1 is 230A, the current setting value 2 is 250A, the current setting value 3 is 295A, and the flash speed is The acceleration voltage of the accelerated burning stage is 430V, the current setting value 1 is 230A, the current setting value 2 is 250A, the current setting value 3 is 295A, and the acceleration speed is 1.7mm/s; the charged upsetting time of the upsetting stage is 1.2s, the upsetting time is 2.4s, and the upsetting amount is 16.0mm; the rail consumption in the forging stage is 2.3mm, the forging time is 1.5s, the average speed is 1.53mm/s, and the forging pressure is 60t. The maximum deflection of the three-point static bending of the rail flash welded joint described in this embodiment is 20.1mm when the load is 2200kN, and no fracture occurs, which far exceeds the standard requirements.
实施例5Example 5
本实施例的试验材料为AREMA标准中规定的136RE廓形的过共析钢轨。钢轨实体化学成分实测碳质量分数为0.95％。采用本发明专利中焊接方法进行焊接。预闪光阶段的高压时间为58s、高电压为410V、电流设定值1为220A、电流设定值2为260A、电流设定值3为285A、预闪光距离为7mm、闪光速度为0.4mm/s；闪光阶段的低压时间为120s、低电压为371V、电流设定值1为220A、电流设定值2为260A、电流设定值3为285A、闪光速度为0.4mm/s；加速烧化阶段的加速烧化电压为425V、电流设定值1为220A、电流设定值2为260A、电流设定值3为285A、加速速度为1.5mm/s；顶锻阶段的带电顶锻时间为1.5s，顶锻计时为2.0s，顶锻量为13.0mm；锻造阶段钢轨消耗量为3.5mm，锻造时间为2.0s，平均速度为1.75mm/s，锻造压力为75t。本实施例中所述钢轨闪光焊接头三点静弯的载荷为2640kN时的最大挠度为23.4mm，未发生断裂，远超标准要求。The test material of this embodiment is a hypereutectoid rail with a profile of 136RE specified in the AREMA standard. The measured carbon mass fraction of the rail entity chemical composition is 0.95%. Welding is performed using the welding method in the patent of the present invention. The high-voltage time in the pre-flash stage is 58s, the high voltage is 410V, the current setting value 1 is 220A, the current setting value 2 is 260A, the current setting value 3 is 285A, the pre-flash distance is 7mm, and the flash speed is 0.4mm/s; the low-voltage time in the flash stage is 120s, the low voltage is 371V, the current setting value 1 is 220A, the current setting value 2 is 260A, the current setting value 3 is 285A, and the flash speed is 0.4mm/s ; The accelerated burning voltage in the accelerated burning stage is 425V, the current setting value 1 is 220A, the current setting value 2 is 260A, the current setting value 3 is 285A, and the acceleration speed is 1.5mm/s; the charged upsetting time in the upsetting stage is 1.5s, the upsetting time is 2.0s, and the upsetting amount is 13.0mm; the rail consumption in the forging stage is 3.5mm, the forging time is 2.0s, the average speed is 1.75mm/s, and the forging pressure is 75t. The maximum deflection of the three-point static bending of the rail flash welded joint described in this embodiment is 23.4mm when the load is 2640kN, and no fracture occurs, which far exceeds the standard requirements.
实施例6Example 6
本实施例的试验材料为AREMA标准中规定的136RE廓形的过共析钢轨。钢轨实体化学成分实测碳质量分数为1.01％。采用本发明专利中焊接方法进行焊接。预闪光阶段的高压时间为65s、高电压为440V、电流设定值1为250A、电流设定值2为270A、电流设定值3为300A、预闪光距离为10mm、闪光速度为0.6mm/s；闪光阶段的低压时间为140s、低电压为390V、电流设定值1为250A、电流设定值2为270A、电流设定值3为300A、闪光速度为0.6mm/s；加速烧化阶段的加速烧化电压为450V、电流设定值1为250A、电流设定值2为270A、电流设定值3为300A、加速速度为2.0mm/s；顶锻 阶段的带电顶锻时间为2.0s，顶锻计时为3.0s，顶锻量为18.0mm；锻造阶段钢轨消耗量为4.0mm，锻造时间为3.0s，平均速度为2.60mm/s，锻造压力为80t。本实施例中所述钢轨闪光焊接头三点静弯的载荷为2610kN时的最大挠度为21.2mm，未发生断裂，远超标准要求。The test material of this embodiment is a hypereutectoid rail with a profile of 136RE specified in the AREMA standard. The measured carbon mass fraction of the rail entity chemical composition is 1.01%. Welding is performed using the welding method in the patent of the present invention. The high voltage time in the pre-flash stage is 65s, the high voltage is 440V, the current setting value 1 is 250A, the current setting value 2 is 270A, the current setting value 3 is 300A, the pre-flash distance is 10mm, and the flash speed is 0.6mm/s; the low voltage time in the flash stage is 140s, the low voltage is 390V, the current setting value 1 is 250A, the current setting value 2 is 270A, the current setting value 3 is 300A, and the flash speed is 0.6mm/s; the accelerated burning voltage in the accelerated burning stage is 450V, the current setting value 1 is 250A, the current setting value 2 is 270A, the current setting value 3 is 300A, and the acceleration speed is 2.0mm/s; the top forging The live upsetting time of the stage is 2.0s, the upsetting time is 3.0s, the upsetting amount is 18.0mm; the rail consumption in the forging stage is 4.0mm, the forging time is 3.0s, the average speed is 2.60mm/s, and the forging pressure is 80t. The maximum deflection of the three-point static bending of the rail flash welded joint described in this embodiment is 21.2mm when the load is 2610kN, and no fracture occurs, which far exceeds the standard requirements.
对比例Comparative Example
本对比例的试验材料为AREMA标准中规定的136RE廓形的过共析钢轨。钢轨实体化学成分实测碳质量分数为1.01％。未采用本发明专利中焊接方法进行焊接。预闪光阶段的高压时间为65s、高电压为445V、电流设定值1为240A、电流设定值2为260A、电流设定值3为275A、预闪光距离为9.5mm、闪光速度为0.55mm/s；闪光阶段的低压时间为138s、低电压为385V、电流设定值1为240A、电流设定值2为260A、电流设定值3为275A、闪光速度为0.6mm/s；加速烧化阶段的加速烧化电压为447V、电流设定值1为240A、电流设定值2为260A、电流设定值3为275A、加速速度为2.0mm/s；顶锻阶段的带电顶锻时间为2.0s，顶锻计时为2.7s，顶锻量为16.8mm；无锻造阶段。本对比例中所述钢轨闪光焊接头三点静弯的载荷仅为1557kN时的最大挠度为6.6mm，发生断裂，远不能满足标准要求。The test material of this comparative example is a hypereutectoid rail of 136RE profile specified in the AREMA standard. The actual carbon mass fraction of the rail entity chemical composition is 1.01%. The welding method in the patent of the present invention is not used for welding. The high voltage time of the pre-flash stage is 65s, the high voltage is 445V, the current setting value 1 is 240A, the current setting value 2 is 260A, the current setting value 3 is 275A, the pre-flash distance is 9.5mm, and the flash speed is 0.55mm/s; the low voltage time of the flash stage is 138s, the low voltage is 385V, the current setting value 1 is 240A, the current setting value 2 is 260A, the current setting value 3 is 275A, and the flash speed is 0.6mm/s; the accelerated burning voltage of the accelerated burning stage is 447V, the current setting value 1 is 240A, the current setting value 2 is 260A, the current setting value 3 is 275A, and the acceleration speed is 2.0mm/s; the charged upsetting time of the upsetting stage is 2.0s, the upsetting timing is 2.7s, and the upsetting amount is 16.8mm; there is no forging stage. The maximum deflection of the rail flash welded joint under three-point static bending in this comparative example is only 6.6 mm when the load is 1557 kN, resulting in fracture, which is far from meeting the standard requirements.
静弯试验是采用三点或四点支撑的方法，以一定的加载速率，向钢轨接头施加载荷，直到载荷达到标准规定值不断，并且最大挠度大于标准规定值，则判定接头静弯性能合格，不同的轨型对应不同的载荷与挠度值。静弯载荷主要体现了接头的结合强度、接头外观以及内部缺陷指标，挠度主要体现了接头强韧性指标。若接头焊接工艺不良，极有可能因为灰斑、未熔合或者过烧等缺陷导致接头在未达到标准规定的载荷值前断裂，或者因为接头热输入和顶锻量匹配不当、焊后处理方法不当导致接头偏硬或偏软，使接头挠度达不到标准要求The static bending test uses a three-point or four-point support method to apply load to the rail joint at a certain loading rate until the load reaches the standard value and the maximum deflection is greater than the standard value. The static bending performance of the joint is judged to be qualified. Different rail types correspond to different load and deflection values. The static bending load mainly reflects the bonding strength, appearance and internal defect indicators of the joint, and the deflection mainly reflects the strength and toughness indicators of the joint. If the welding process of the joint is poor, it is very likely that the joint will break before the load value specified in the standard is reached due to defects such as gray spots, lack of fusion or overburning, or the joint may be too hard or too soft due to improper matching of the heat input and upsetting amount of the joint, or improper post-weld treatment methods, so that the joint deflection does not meet the standard requirements.
实施例1的钢轨闪光焊接头三点静弯的载荷为2000kN时的最大挠度为23.5mm，未发生断裂；实施例2的钢轨闪光焊接头三点静弯的载荷为2200kN时的最大挠度为27.4mm，未发生断裂；实施例3的钢轨闪光焊接头三点静弯的载荷为2500kN时的最大挠度为26.2mm，未发生断裂；实施 例4的钢轨闪光焊接头三点静弯的载荷为2200kN时的最大挠度为20.1mm，未发生断裂；实施例5的钢轨闪光焊接头三点静弯的载荷为2640kN时的最大挠度为23.4mm，未发生断裂；实施例6的钢轨闪光焊接头三点静弯的载荷为2610kN时的最大挠度为21.2mm，未发生断裂。The maximum deflection of the rail flash welded joint of Example 1 at the three-point static bending load of 2000 kN was 23.5 mm, and no fracture occurred; the maximum deflection of the rail flash welded joint of Example 2 at the three-point static bending load of 2200 kN was 27.4 mm, and no fracture occurred; the maximum deflection of the rail flash welded joint of Example 3 at the three-point static bending load of 2500 kN was 26.2 mm, and no fracture occurred; The maximum deflection of the three-point static bending of the rail flash welded joint of Example 4 was 20.1 mm when the load was 2200 kN, and no fracture occurred; the maximum deflection of the three-point static bending of the rail flash welded joint of Example 5 was 23.4 mm when the load was 2640 kN, and no fracture occurred; the maximum deflection of the three-point static bending of the rail flash welded joint of Example 6 was 21.2 mm when the load was 2610 kN, and no fracture occurred.
我国对于静弯标准要求是破断载荷不小于1450kN(60kg/m，轨头受压)，对挠度不作要求；实施例1-6的钢轨闪光焊接头三点静弯的载荷均远大于国标(1450kN)。my country's static bending standard requires a breaking load of no less than 1450 kN (60 kg/m, rail head under pressure), and no requirement is made for deflection; the loads of three-point static bending of the rail flash welded joints of Examples 1-6 are all much greater than the national standard (1450 kN).
对比例未采用本发明专利中焊接方法进行焊接，可以看出钢轨闪光焊接头三点静弯的载荷仅为1557kN时的最大挠度为6.6mm，发生断裂。与实施例1-6的方法焊接的钢轨的性能差距较大。The comparative example did not use the welding method of the present invention for welding. It can be seen that the maximum deflection of the rail flash weld joint at the three-point static bending load was only 1557 kN, and the rail broke. The performance gap between the rails welded by the method of Examples 1-6 is large.
以上是本发明公开的示例性实施例，但是应当注意，在不背离权利要求限定的本发明实施例公开的范围的前提下，可以进行多种改变和修改。尽管本发明实施例公开的元素可以以个体形式描述或要求，但除非明确限制为单数，也可以理解为多个。The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope of the embodiments disclosed in the claims. Although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.
所属领域的普通技术人员应当理解：以上任何实施例的讨论仅为示例性的，并非旨在暗示本发明实施例公开的范围(包括权利要求)被限于这些例子；在本发明实施例的思路下，以上实施例或者不同实施例中的技术特征之间也可以进行组合，并存在如上本发明实施例的不同方面的许多其它变化，为了简明它们没有在细节中提供。因此，凡在本发明实施例的精神和原则之内，所做的任何省略、修改、等同替换、改进等，均应包含在本发明实施例的保护范围之内。 A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the idea of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims (10)

  1. 一种提升钢轨闪光对焊接头的结合强度的方法，其特征在于，所述方法采用移动式闪光焊机实现焊接过程，所述焊接过程包括预闪光、闪光、加速烧化、顶锻及锻造；在所述焊接过程结束后，将接头至于空气中自然冷却至室温；A method for improving the bonding strength of a rail flash butt weld joint, characterized in that the method uses a mobile flash welder to implement a welding process, the welding process includes pre-flash, flash, accelerated burning, upsetting and forging; after the welding process is completed, the joint is naturally cooled to room temperature in the air;
    其中，顶锻阶段的顶锻量为5.0mm～18.0mm；锻造阶段的锻造压力为60t～80t。Among them, the upsetting amount in the upsetting stage is 5.0mm~18.0mm; the forging pressure in the forging stage is 60t~80t.
  2. 根据权利要求1所述的方法，其特征在于，所述钢轨选自碳的质量分数处于0.60wt％～0.90wt％的珠光体钢轨以及碳的质量分数处于0.90wt％～1.20wt％的过共析钢轨。The method according to claim 1, characterized in that the rail is selected from a pearlite rail having a carbon mass fraction of 0.60wt% to 0.90wt% and a hypereutectoid rail having a carbon mass fraction of 0.90wt% to 1.20wt%.
  3. 根据权利要求2所述的方法，其特征在于，所述珠光体钢轨包括以下组分：碳的质量分数处于0.60％～0.90％、硅的质量分数处于0.10％～1.00％、锰的质量分数处于0.60％～1.50％、磷和硫的质量分数均小于0.020％，铬的质量分数小于0.3％以及钒的质量分数小于0.01％。The method according to claim 2 is characterized in that the pearlite rail comprises the following components: a mass fraction of carbon is between 0.60% and 0.90%, a mass fraction of silicon is between 0.10% and 1.00%, a mass fraction of manganese is between 0.60% and 1.50%, a mass fraction of phosphorus and sulfur is less than 0.020%, a mass fraction of chromium is less than 0.3%, and a mass fraction of vanadium is less than 0.01%.
  4. 根据权利要求2所述的方法，其特征在于，所述过共析钢轨包括以下组分：碳的质量分数处于0.90％～1.20％、硅的质量分数处于0.10％～1.00％、锰的质量分数处于0.60％～1.50％、磷和硫的质量分数均小于0.020％，铬的质量分数小于0.3％以及钒的质量分数小于0.01％。The method according to claim 2 is characterized in that the hypereutectoid rail comprises the following components: a mass fraction of carbon is between 0.90% and 1.20%, a mass fraction of silicon is between 0.10% and 1.00%, a mass fraction of manganese is between 0.60% and 1.50%, a mass fraction of phosphorus and sulfur is less than 0.020%, a mass fraction of chromium is less than 0.3%, and a mass fraction of vanadium is less than 0.01%.
  5. 根据权利要求1所述的方法，其特征在于，顶锻阶段的带电顶锻时间为0.1s～2.0s，顶锻计时为1.0s～3.0s。The method according to claim 1 is characterized in that the charged upsetting time in the upsetting stage is 0.1s to 2.0s, and the upsetting timing is 1.0s to 3.0s.
  6. 根据权利要求1所述的方法，其特征在于，锻造阶段的钢轨消耗量为2.0mm～4.0mm，锻造时间为1.5s～3.0s，平均速度为0.60mm/s～2.60mm/s。The method according to claim 1 is characterized in that the rail consumption in the forging stage is 2.0 mm to 4.0 mm, the forging time is 1.5 s to 3.0 s, and the average speed is 0.60 mm/s to 2.60 mm/s.
  7. 根据权利要求1所述的方法，其特征在于，预闪光阶段的电压为370V～440V且电压时间为45s～65s，电流值为180A～300A，预闪光距离为2mm～10mm，闪光速度为0.1mm/s～0.6mm/s。The method according to claim 1 is characterized in that the voltage in the pre-flash stage is 370V to 440V and the voltage time is 45s to 65s, the current value is 180A to 300A, the pre-flash distance is 2mm to 10mm, and the flash speed is 0.1mm/s to 0.6mm/s.
  8. 根据权利要求1所述的方法，其特征在于，闪光阶段的电压为320V～390V且电压时间为80s～140s，电流值为180A～300A，闪光速度为0.1mm/s～ 0.6mm/s。The method according to claim 1 is characterized in that the voltage in the flash stage is 320V to 390V and the voltage time is 80s to 140s, the current value is 180A to 300A, and the flash speed is 0.1mm/s to 0.6mm/s.
  9. 根据权利要求1所述的方法，其特征在于，加速烧化阶段的电压为380V～450V，电流为180A～300A，加速速度为0.5mm/s～2.0mm/s。The method according to claim 1 is characterized in that the voltage in the accelerated burning stage is 380V to 450V, the current is 180A to 300A, and the acceleration speed is 0.5mm/s to 2.0mm/s.
  10. 一种由权利要求1-9中任意一项所述的方法焊接得到的钢轨。 A steel rail welded by the method according to any one of claims 1 to 9.
PCT/CN2023/093540 2022-11-03 2023-05-11 Method for improving bonding strength of rail flash-butt welded joint WO2024093184A1 (en)

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