CN115488483B - Method for improving bonding strength of steel rail flash butt welding joint - Google Patents
Method for improving bonding strength of steel rail flash butt welding joint Download PDFInfo
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- CN115488483B CN115488483B CN202211368275.1A CN202211368275A CN115488483B CN 115488483 B CN115488483 B CN 115488483B CN 202211368275 A CN202211368275 A CN 202211368275A CN 115488483 B CN115488483 B CN 115488483B
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- 238000003466 welding Methods 0.000 title claims abstract description 125
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 122
- 239000010959 steel Substances 0.000 title claims abstract description 122
- 238000000034 method Methods 0.000 title claims abstract description 58
- 238000005242 forging Methods 0.000 claims abstract description 40
- 230000008569 process Effects 0.000 claims abstract description 15
- 238000001816 cooling Methods 0.000 claims abstract description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 23
- 229910052799 carbon Inorganic materials 0.000 claims description 23
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 6
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 6
- 229910052804 chromium Inorganic materials 0.000 claims description 6
- 239000011651 chromium Substances 0.000 claims description 6
- 229910052698 phosphorus Inorganic materials 0.000 claims description 6
- 239000011574 phosphorus Substances 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- 229910052717 sulfur Inorganic materials 0.000 claims description 6
- 239000011593 sulfur Substances 0.000 claims description 6
- 229910052720 vanadium Inorganic materials 0.000 claims description 6
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 6
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 239000011572 manganese Substances 0.000 claims description 4
- 238000005452 bending Methods 0.000 abstract description 29
- 230000003068 static effect Effects 0.000 abstract description 29
- 230000007547 defect Effects 0.000 abstract description 9
- 238000012360 testing method Methods 0.000 description 13
- 239000000126 substance Substances 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 7
- 229910000734 martensite Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000005422 blasting Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005493 welding type Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
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- 230000002349 favourable effect Effects 0.000 description 1
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- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
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Classifications
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- 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
Abstract
The invention discloses a method for improving the bonding strength of a steel rail flash butt welding joint, which adopts a movable flash welding machine to realize a welding process, wherein the welding process comprises pre-flashing, accelerating burning, upsetting and forging; after the welding process is finished, naturally cooling the joint to room temperature in the air; wherein, the upsetting amount in the upsetting stage is 5.0 mm-18.0 mm; the forging pressure in the forging stage is 60 t-80 t. The invention also discloses a steel rail welded by the method. The method for improving the bonding strength of the steel rail flash butt welding joint provided by the invention has the advantages that the steel rail welding seam welded by the method has no welding defects such as gray spots, unwelded, overburning and the like, the steel rail fracture is rough, and the static bending performance of the steel rail flash welding joint can be effectively ensured to be greatly improved.
Description
Technical Field
The invention belongs to the technical field of steel rail welding, and particularly relates to a method for improving the bonding strength of a steel rail flash butt welding joint.
Background
With the development of global rail routes to high speed and heavy load, rail welding is also becoming a focus of attention. At present, the main current rail flash butt welding at home and abroad is a welding method which clamps rails at two sides through clamping devices such as conductive electrodes, the end surfaces of the rails are contacted after the rails are electrified, and the conductive current generates resistance heat at the contact point, so that the contact point is quickly melted, flash is formed and is accompanied with strong splashing, a certain upsetting force is applied after a certain flash amount, and the rails are recrystallized and formed at a high temperature. The method is mainly divided into a fixed flash welding type and a movable flash welding type. The movable flash welding is commonly used for track laying site construction welding due to the characteristics of small equipment, convenient movement and the like, and the fixed flash welding of the steel rail is commonly used for fixing welding equipment in a factory building, so the fixed flash welding is also commonly called factory welding or base welding. The greatest difference between the two is the way the rail is heated, except for the application scenario. The movable flash welding heats the steel rail by intermittent pulse flash explosion or continuous flash explosion, so the movable flash welding can be divided into pulse flash and continuous flash. Fixed flash welding is typically performed by directly shorting the rails and heating the rails by resistive heating without (or with a small amount of) flash, also commonly referred to as short-circuit preheat flash welding.
Currently, the main international mainstream steel rail flash welding standard mainly comprises China railway industry standard series standard TB/T1632.2-2014, steel rail welding part 2: flash welding, american society OF railway works 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 tracks.Part3: welding in ASSOCIATION with crossing construction, australian standard AS1085.20-2012,Railway Track material Part20: welding of steel rail. All the existing flash welding standards and technical conditions of enterprises for the pearlitic steel rail are suitable for specific regulations on the microscopic structure of the flash welding head of the steel rail. The microstructure of the steel rail joint weld joint and the heat affected zone in TB/T1632.2 is pearlite, a small amount of ferrite can be generated, and the microstructure of martensite, bainite and other harmful structures are not generated; AMEMA states that the weld and heat affected zone of the rail joint desirably has a 100% pearlitic structure, which affects the results of static bending tests once the joint has a non-tempered martensitic structure; the European standard BS EN14587 standard specifies that, when observed with an optical microscope at a magnification of 100X, needle-like carbides with signs of embrittlement and inter-crystalline continuous network carbides do not appear, allowing a granular martensitic structure to appear; the australian standard AS1085.20 specifies that the rail joint microstructure should be a pearlitic structure substantially free of intergranular cementite and untempered martensite, allowing for the presence of small amounts of martensite if the requirements of other tests are met. The hardness of the longitudinal section of the steel rail flash welding head, namely, after the steel rail is split along the longitudinal rolling direction of the steel rail, the hardness value of the steel rail flash welding head within the range of 3-5 mm below the running surface of the joint and 20mm above the width of the heat affected zone at both sides of the joint welding line is checked, wherein certain standard adopts Rockwell hardness, certain standard adopts Vickers hardness, or both. The hardness of the steel rail welding joint is an important factor affecting the smoothness of the high-speed railway track, and the joint can be ensured to have consistent wear resistance with the circuit steel rail in the service period only if the hardness level of the joint is equal to that of the base metal. The existing problems are that the joint has a softening area in both a welding state and a heat treatment state, saddle-shaped abrasion can occur during service, and the smoothness of a circuit is deteriorated. The correct post-welding treatment process can improve the joint structure, reduce the softening degree and meet the wear-resisting performance requirement of the joint as much as possible. The static bending test of the steel rail flash welding head is the most widely used method for evaluating the overall performance of the steel rail joint at home and abroad at present, and all steel rail joint test standards are specified. Mainly comprises two indexes, namely load and deflection. The static bending test is to apply load to the rail joint at a certain loading rate by adopting a three-point or four-point supporting method until the load reaches a standard specified value and the maximum deflection is larger than the standard specified value, and then judge that the static bending performance of the joint is qualified, and different rail types correspond to different load and deflection values. European Standard BS EN14587-2:2009 requires joint minimum loads and deflections of not less than 1600KN and 20mm (60 kg/m rail, head pressed), respectively. European Standard BS EN14587-2:2009 requires a minimum stress of 900MPa at the joint rail bottom, and the minimum load and deflection after conversion are not less than 1670KN and 20mm (60 kg/m rail, rail head pressed) respectively. The standard requirement of static bending in China is that the breaking load is not less than 1450kN (60 kg/m, rail head is pressed), and the deflection is not required. The static bending load mainly shows the joint strength, the joint appearance and the internal defect index of the joint, and the deflection mainly shows the joint toughness index. If the welding process of the joint is poor, the joint is likely to break before the joint does not reach the standard specified load value due to defects such as gray spots, unfused or overburning, or the joint is hard or soft due to improper matching of the heat input and upsetting amount of the joint and improper post-welding treatment method, so that the deflection of the joint cannot meet the standard requirement.
In view of the foregoing, a method for improving the bonding strength of a flash butt welding joint of a steel rail is needed in the railway engineering field, so as to effectively ensure that the static bending performance of the flash butt welding joint of the steel rail is greatly improved.
Disclosure of Invention
Based on the method, in order to make up the defects of the existing steel rail welding technology, the welding method of the internal damage-resistant pearlitic steel rail or the high-strength pearlitic steel rail is provided, and the method can effectively relieve the occurrence of abnormal defects in the microstructure of the welded joint, so that the running safety of a railway is ensured.
In order to achieve the above purpose, the following technical scheme is adopted:
the invention provides a method for improving the bonding strength of a steel rail flash butt welding joint, which adopts a movable flash welding machine to realize a welding process, wherein the welding process comprises pre-flashing, accelerating burning, upsetting and forging; after the welding process is finished, naturally cooling the joint to room temperature in the air;
wherein, the upsetting amount in the upsetting stage is 5.0 mm-18.0 mm; the forging pressure in the forging stage is 60 t-80 t.
Further, the steel rail is selected from a pearlitic steel rail with a mass fraction of carbon of 0.60-0.90 wt% and an hypereutectoid steel rail with a mass fraction of carbon of 0.90-1.20 wt%.
Further, the pearlitic steel rail comprises the following components: the mass fraction of carbon is 0.60% -0.90%, the mass fraction of silicon is 0.10% -1.00%, the mass fraction of manganese is 0.60% -1.50%, the mass fraction of phosphorus and sulfur are 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%.
Further, the hypereutectoid steel rail comprises the following components: the mass fraction of carbon is 0.90% -1.20%, the mass fraction of silicon is 0.10% -1.00%, the mass fraction of manganese is 0.60% -1.50%, the mass fraction of phosphorus and sulfur are 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%.
Further, the charged upsetting time in the upsetting stage is 0.1s to 2.0s, and the upsetting time is 1.0s to 3.0s.
Further, the consumption of the steel rail in the forging stage is 2.0-4.0 mm, the forging time is 1.5-3.0 s, and the average speed is 0.60-2.60 mm/s.
Further, the voltage in the pre-flashing stage is 370V-440V, the voltage time is 45 s-65 s, the current value is 180A-300A, the pre-flashing distance is 2 mm-10 mm, and the flashing speed is 0.1 mm/s-0.6 mm/s.
Further, the current value in the pre-flash stage is divided into three stages of set values, namely, 180A-250A for the current set value 1, 200A-270A for the current set value 2 and 220A-300A for the current set value 3.
Further, the voltage in the flash stage is 320V-390V, the voltage time is 80 s-140 s, the current value is 180A-300A, and the flash speed is 0.1 mm/s-0.6 mm/s.
Further, the current value in the flash stage is divided into three stages of set values, namely, 180A-250A for current set value 1, 200A-270A for current set value 2 and 220A-300A for current set value 3.
Further, the voltage at the stage of accelerating the burning is 380V-450V, the current is 180A-300A, and the accelerating speed is 0.5 mm/s-2.0 mm/s.
Further, the current value in the accelerated burning stage is divided into three stages of setting values, namely, 180A-250A for the current setting value 1, 200A-270A for the current setting value 2 and 220A-300A for the current setting value 3.
The invention also provides a steel rail welded by the method.
The invention has the following beneficial technical effects:
the invention mainly aims at a pearlitic steel rail with the mass fraction of carbon being 0.60-0.90% and an hypereutectoid steel rail with the mass fraction of carbon being 0.90-1.20% and provides a method for improving the bonding strength of a steel rail flash butt welding joint. The steel rail welding seam welded by the method has no welding defects such as gray spots, unwelded parts, overburning and the like, and the steel rail fracture is rough, so that the static bending performance of the steel rail flash welding head can be effectively ensured to be greatly improved.
The method for improving the bonding strength of the steel rail flash butt welding joint disclosed by the invention is characterized in that the steel rail is heated in a middle-early heating stage by a flash method different from a pulse flash in the prior art, and meanwhile, a pressure maintaining stage in the prior art is removed, so that the steel rail flash butt welding joint is changed into a forging stage. The forging stage of the method for improving the joint bonding strength of the steel rail flash butt welding adopts hydraulic flow control and is accompanied with displacement change, and the joint bonding strength is greatly improved through newly added forging.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following embodiments of the present invention will be described in further detail with reference to specific embodiments.
In the invention, the joint and the welding head are areas with the length of 80-120mm, including welding seams and/or heat affected zones, obtained after welding, and the center of the areas is a steel rail welding seam. In the present invention, the "room temperature" is a temperature in the range of 5 to 40 ℃.
The embodiment of the invention mainly aims at a pearlitic steel rail with the mass fraction of carbon being 0.60-0.90% and an hypereutectoid steel rail with the mass fraction of carbon being 0.90-1.20% and provides a method for improving the bonding strength of the steel rail flash butt welding joint. The steel rail welding seam welded by the method has no welding defects such as gray spots, unwelded parts, overburning and the like, and the steel rail fracture is rough, so that the static bending performance of the steel rail flash butt welding joint can be effectively ensured to be greatly improved.
In order to achieve the above purpose, the method for improving the bonding strength of the steel rail flash butt welding joint is achieved by a steel rail movable flash welding machine, and the whole welding process comprises 5 main stages of pre-flashing, accelerating burning, upsetting, forging and the like. After the flash welding is finished, the joint is naturally cooled to room temperature in the air.
The mass fraction of the carbon is 0.60% -0.90% of the pearlitic steel rail. The main chemical components of the pearlitic steel rail comprise 0.60-0.90% of carbon, 0.10-1.00% of silicon, 0.60-1.50% of manganese, no more than 0.020% of phosphorus and sulfur, no more than 0.3% of chromium and no more than 0.01% of vanadium. The minimum tensile strength of the pearlitic steel rail is 800MPa, and the minimum hardness of the rail head is 250HB.
The mass fraction of the carbon is 0.90-1.20% of hypereutectoid steel rail. The hypereutectoid steel rail comprises the main chemical components of 0.90-1.20% of carbon, 0.10-1.00% of silicon, 0.60-1.50% of manganese, no more than 0.020% of phosphorus and sulfur, no more than 0.3% of chromium and no more than 0.01% of vanadium. The minimum tensile strength of the steel rail is 1300MPa, and the minimum hardness of the rail head is 400HB.
The main function of the pre-flashing stage is to enable the section to be welded of the steel rail to be flat and clean through flashing blasting, and provide relatively uniform and flat favorable conditions and basic heat for subsequent flashing. To achieve the above object, the control is mainly performed by 7 variables such as high voltage time, high voltage, current set value 1, current set value 2, current set value 3, pre-flash distance, flash speed, etc. The high voltage in the pre-flash stage is 370V-440V and the voltage time is 45 s-65 s; the current value in the pre-flashing stage is divided into three stages of set values, wherein the current set value 1 is 180A-250A, the current set value 2 is 200A-270A, and the current set value 3 is 220A-300A; the pre-flashing distance is 2 mm-10 mm, and the flashing speed is 0.1 mm/s-0.6 mm/s.
The main function of the flashing stage is to continuously and evenly flash on the basis of the accumulated heat of the pre-flashing in the earlier stage, and the steel rail is continuously heated by utilizing the generated by the lintel blasting, so that a certain temperature gradient is formed in the longitudinal direction of the steel rail, the end face of the steel rail is heated to a sufficient temperature, and the condition is laid for accelerating the burning process. To achieve the above object, the control is mainly performed by 6 variables such as low voltage time, low voltage, current set point 1, current set point 2, current set point 3, flash speed, etc. The low voltage in the flash stage is 320-390V and the voltage time is 80-140 s; the current value in the flash stage is divided into three stages of set values, wherein the current set value 1 is 180A-250A, the current set value 2 is 200A-270A, and the current set value 3 is 220A-300A; the flash speed is 0.1mm/s to 0.6mm/s.
The accelerating burning stage mainly aims at forming a protective atmosphere for preventing the end face from oxidizing in the whole welding area, and finally forming proper temperature field distribution to provide conditions for upsetting. To achieve the above object, the control is mainly performed by 5 variables such as accelerating burning voltage, current setting value 1, current setting value 2, current setting value 3, accelerating speed, etc. The accelerating burning voltage of the accelerating burning stage is 380V-450V, the current value of the accelerating burning stage is divided into three stages of setting values, the current setting value 1 is 180A-250A, the current setting value 2 is 200A-270A, and the current setting value 3 is 220A-300A; the acceleration speed is 0.5 mm/s-2.0 mm/s.
The electrified upsetting time in the upsetting stage is 0.1 s-2.0 s, the upsetting time is 1.0 s-3.0 s, and the upsetting amount is 5.0 mm-18.0 mm.
The forging stage mainly aims to continuously apply load to the steel rail joint in the process of crystallizing the joint metal after the steel rail is upset, so that the joint bonding strength is enhanced. In order to achieve the purpose, the consumption of the steel rail in the forging stage is 2.0-4.0 mm, the forging time is 1.5-3.0 s, the average speed is 0.60-2.60 mm/s, and the forging pressure is 60-80 t.
The method for processing the butt joint after the flash welding is finished. The method is characterized in that the welded joint is not required to be treated, and the joint is directly placed in the air to be naturally cooled to the room temperature.
Example 1
The test material of this example is a 60E1 profile pearlitic rail as specified in the BS EN 13674-1 standard. The mass fraction of carbon measured by the chemical composition of the steel rail entity is 0.75%. The welding method disclosed by the invention is adopted for welding. The high voltage time of the pre-flash stage is 45s, the high voltage is 370V, the current set value 1 is 180A, the current set value 2 is 200A, the current set value 3 is 220A, the pre-flash distance is 2mm, and the flash speed is 0.1mm/s; the low voltage time of the flash stage is 80s, the low voltage is 320V, the current set value 1 is 180A, the current set value 2 is 200A, the current set value 3 is 220A, and the flash speed is 0.1mm/s; the accelerating burning voltage in the accelerating burning stage is 380V, the current set value 1 is 180A, the current set value 2 is 200A, the current set value 3 is 220A, and the accelerating speed is 0.5mm/s; the electrified upsetting time in the upsetting stage is 0.1s, the upsetting time is 1.0s, and the upsetting amount is 5.0mm; the consumption of the steel rail 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. In the embodiment, the maximum deflection of the three-point static bending load of the steel rail flash welding head is 23.5mm when the load is 2000kN, the steel rail flash welding head is not broken, and the steel rail flash welding head far exceeds the standard requirement.
Example 2
The test material of this example was a 60kg profile pearlitic rail AS specified in the AS 1085-1 standard. The mass fraction of carbon measured by the chemical composition of the steel rail entity is 0.65%. The welding method disclosed by the invention is adopted for welding. The high voltage time of the pre-flash stage is 56s, the high voltage is 400V, the current set value 1 is 220A, the current set value 2 is 240A, the current set value 3 is 260A, the pre-flash distance is 6mm, and the flash speed is 0.3mm/s; the low voltage time of the flash stage is 110s, the low voltage is 350V, the current set value 1 is 220A, the current set value 2 is 240A, the current set value 3 is 260A, and the flash speed is 0.3mm/s; the accelerating burning voltage in the accelerating burning stage is 405V, the current set value 1 is 220A, the current set value 2 is 240A, the current set value 3 is 260A, and the accelerating speed is 1.1mm/s; the electrified upsetting time in the upsetting stage is 0.5s, the upsetting time is 2.0s, and the upsetting amount is 12.0mm; the consumption of the steel rail 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. In the embodiment, the maximum deflection of the steel rail flash welding head at the three-point static bending load of 2200kN is 27.4mm, and the steel rail flash welding head is not broken and far exceeds the standard requirement.
Example 3
The test material of this example was a 115RE profile pearlitic rail as specified in the AREMA standard. The mass fraction of carbon measured by the chemical composition of the steel rail entity is 0.81%. The welding method disclosed by the invention is adopted for welding. The high voltage time of the pre-flash stage is 53s, the high voltage is 390V, the current set value 1 is 200A, the current set value 2 is 230A, the current set value 3 is 250A, the pre-flash distance is 5mm, and the flash speed is 0.2mm/s; the low voltage time of the flash stage is 100s, the low voltage is 345V, the current set value 1 is 200A, the current set value 2 is 230A, the current set value 3 is 250A, and the flash speed is 0.2mm/s; the accelerating burning voltage in the accelerating burning stage is 400V, the current set value 1 is 200A, the current set value 2 is 230A, the current set value 3 is 250A, and the accelerating speed is 0.9mm/s; the electrified upsetting time in the upsetting stage is 0.7s, the upsetting time is 1.3s, and the upsetting amount is 10.0mm; the consumption of the steel rail 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. In the embodiment, when the load of the three-point static bending of the steel rail flash welding head is 2500kN, the maximum deflection is 26.2mm, the steel rail flash welding head is not broken, and the steel rail flash welding head far exceeds the standard requirement.
Example 4
The test material of this example was a 136RE profile pearlitic rail as specified in the AREMA standard. The mass fraction of carbon measured by the chemical composition of the steel rail entity is 0.78%. The welding method disclosed by the invention is adopted for welding. The high voltage time of the pre-flash stage is 61s, the high voltage is 420V, the current set value 1 is 230A, the current set value 2 is 250A, the current set value 3 is 295A, the pre-flash distance is 8mm, and the flash speed is 0.5mm/s; the low voltage time of the flash stage is 135s, the low voltage is 380V, the current set value 1 is 230A, the current set value 2 is 250A, the current set value 3 is 295A, and the flash speed is 0.5mm/s; the accelerating burning voltage in the accelerating burning stage is 430V, the current set value 1 is 230A, the current set value 2 is 250A, the current set value 3 is 295A, and the accelerating speed is 1.7mm/s; the electrified upsetting time in the upsetting stage is 1.2s, the upsetting time is 2.4s, and the upsetting amount is 16.0mm; the consumption of the steel rail 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. In the embodiment, the maximum deflection of the steel rail flash welding head at the three-point static bending load of 2200kN is 20.1mm, and the steel rail flash welding head is not broken and far exceeds the standard requirement.
Example 5
The test material of this example was an hypereutectoid steel rail of 136RE profile as specified in the AREMA standard. The mass fraction of carbon measured by the chemical composition of the steel rail entity is 0.95%. The welding method disclosed by the invention is adopted for welding. The high voltage time of the pre-flash stage is 58s, the high voltage is 410V, the current set value 1 is 220A, the current set value 2 is 260A, the current set value 3 is 285A, the pre-flash distance is 7mm, and the flash speed is 0.4mm/s; the low voltage time of the flash stage is 120s, the low voltage is 371V, the current set value 1 is 220A, the current set value 2 is 260A, the current set value 3 is 285A, and the flash speed is 0.4mm/s; the accelerating burning voltage in the accelerating burning stage is 425V, the current set value 1 is 220A, the current set value 2 is 260A, the current set value 3 is 285A, and the accelerating speed is 1.5mm/s; the electrified upsetting time in the upsetting stage is 1.5s, the upsetting time is 2.0s, and the upsetting amount is 13.0mm; the consumption of the steel rail 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. In the embodiment, the maximum deflection of the steel rail flash welding head at the three-point static bending load of 2640kN is 23.4mm, and the steel rail flash welding head is not broken and far exceeds the standard requirement.
Example 6
The test material of this example was an hypereutectoid steel rail of 136RE profile as specified in the AREMA standard. The mass fraction of carbon measured by the chemical composition of the steel rail entity is 1.01%. The welding method disclosed by the invention is adopted for welding. The high voltage time of the pre-flash stage is 65s, the high voltage is 440V, the current set value 1 is 250A, the current set value 2 is 270A, the current set value 3 is 300A, the pre-flash distance is 10mm, and the flash speed is 0.6mm/s; the low voltage time of the flash stage is 140s, the low voltage is 390V, the current set value 1 is 250A, the current set value 2 is 270A, the current set value 3 is 300A, and the flash speed is 0.6mm/s; the accelerating burning voltage in the accelerating burning stage is 450V, the current set value 1 is 250A, the current set value 2 is 270A, the current set value 3 is 300A, and the accelerating speed is 2.0mm/s; the electrified upsetting time in the upsetting stage is 2.0s, the upsetting time is 3.0s, and the upsetting amount is 18.0mm; the consumption of the steel rail 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. In the embodiment, the maximum deflection of the three-point static bending load of the steel rail flash welding head is 21.2mm when the load is 2610kN, the steel rail flash welding head is not broken, and the steel rail flash welding head far exceeds the standard requirement.
Comparative example
The test material of this comparative example was an hypereutectoid steel rail of 136RE profile as specified in the AREMA standard. The mass fraction of carbon measured by the chemical composition of the steel rail entity is 1.01%. The welding method 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 set value 1 is 240A, the current set value 2 is 260A, the current set 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 set value 1 is 240A, the current set value 2 is 260A, the current set value 3 is 275A, and the flash speed is 0.6mm/s; the accelerating burning voltage in the accelerating burning stage is 447V, the current set value 1 is 240A, the current set value 2 is 260A, the current set value 3 is 275A, and the accelerating speed is 2.0mm/s; the electrified upsetting time in the upsetting stage is 2.0s, the upsetting time is 2.7s, and the upsetting amount is 16.8mm; there is no forging stage. In the comparative example, the maximum deflection of the steel rail flash welding head at three points is 6.6mm when the static bending load is 1557kN only, and the steel rail flash welding head is broken and can not meet the standard requirement.
The static bending test is to apply load to the rail joint at a certain loading rate by adopting a three-point or four-point supporting method until the load reaches a standard specified value and the maximum deflection is larger than the standard specified value, and then judge that the static bending performance of the joint is qualified, and different rail types correspond to different load and deflection values. The static bending load mainly shows the joint strength, the joint appearance and the internal defect index of the joint, and the deflection mainly shows the joint toughness index. If the welding process of the joint is poor, the joint is likely to break before the joint does not reach the standard specified load value due to the defects of gray spots, unfused or overburning, or the joint is hard or soft due to the improper matching of the heat input and the upsetting amount of the joint and the improper post-welding treatment method, so that the deflection of the joint does not reach the standard requirement
The maximum deflection of the steel rail flash welding head of the embodiment 1 is 23.5mm when the load of the three-point static bending is 2000kN, and the steel rail flash welding head is not broken; the maximum deflection of the steel rail flash welding head of the example 2 is 27.4mm when the load of the three-point static bending is 2200kN, and the steel rail flash welding head is not broken; the maximum deflection of the steel rail flash welding head of the embodiment 3 is 26.2mm when the load of three-point static bending is 2500kN, and no fracture occurs; the maximum deflection of the steel rail flash welding head of the example 4 is 20.1mm when the load of the three-point static bending is 2200kN, and the steel rail flash welding head is not broken; the maximum deflection of the steel rail flash welding head of the example 5 is 23.4mm when the load of three-point static bending is 2640kN, and no fracture occurs; the maximum deflection of the example 6 rail flash joint at a three-point static bending load of 2610kN was 21.2mm, and no fracture occurred.
The standard requirement of China for static bending is that the breaking load is not less than 1450kN (60 kg/m, rail head is pressed), and the deflection is not required; the loads of three-point static bending of the steel rail flash welding heads of the examples 1-6 are far greater than national standard (1450 kN).
The comparative example does not adopt the welding method in the patent of the invention for welding, and the maximum deflection of the steel rail flash welding head when the static bending load of three points is 1557kN is 6.6mm, so that the steel rail flash welding head is broken. The performance differences from the rails welded by the methods of examples 1-6 are large.
The foregoing is an exemplary embodiment of the present disclosure, but it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. Although elements of the embodiments of the invention may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.
Those of ordinary skill in the art will appreciate that: the above discussion of any embodiment is merely exemplary and is not intended to imply that the scope of the disclosure of embodiments of the invention, including the claims, is limited to such examples; combinations of features of the above embodiments or in different embodiments are also possible within the idea of an embodiment of the invention and there are many other variations of the different aspects of the embodiments of the invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. of the embodiments should be included in the protection scope of the embodiments of the present invention.
Claims (4)
1. A method for improving the bonding strength of a steel rail flash butt welding joint is characterized in that a movable flash welding machine is adopted to realize a welding process, and the welding process comprises pre-flashing, accelerating burning, upsetting and forging; after the welding process is finished, naturally cooling the joint to room temperature in the air;
wherein, the upsetting amount in the upsetting stage is 5.0-18.0 mm, the electrified upsetting time in the upsetting stage is 0.1-2.0 s, and the upsetting time is 1.0-3.0 s; the forging pressure in the forging stage is 60 t-80 t; the consumption of the steel rail in the forging stage is 2.0-4.0 mm, the forging time is 1.5-3.0 s, and the average speed is 0.60-2.60 mm/s; the voltage in the pre-flashing stage is 370V-440V, the voltage time is 45 s-65 s, the current value is 180A-300A, the pre-flashing distance is 2 mm-10 mm, and the flashing speed is 0.1 mm/s-0.6 mm/s; the voltage in the flashing stage is 320V-390V, the voltage time is 80 s-140 s, the current value is 180A-300A, and the flashing speed is 0.1 mm/s-0.6 mm/s; the voltage of the accelerating burning stage is 380V-450V, the current is 180A-300A, and the accelerating speed is 0.5 mm/s-2.0 mm/s;
the steel rail is selected from a pearlitic steel rail with the mass fraction of carbon being 0.60-0.90-wt% and an hypereutectoid steel rail with the mass fraction of carbon being 0.90-wt-1.20-wt%.
2. The method of claim 1, wherein the pearlitic rail comprises the following components: the mass fraction of carbon is 0.60% -0.90%, the mass fraction of silicon is 0.10% -1.00%, the mass fraction of manganese is 0.60% -1.50%, the mass fraction of phosphorus and sulfur are 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%.
3. The method of claim 1, wherein the hypereutectoid steel rail comprises the following components: the mass fraction of carbon is 0.90% -1.20%, the mass fraction of silicon is 0.10% -1.00%, the mass fraction of manganese is 0.60% -1.50%, the mass fraction of phosphorus and sulfur are 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%.
4. A rail welded by the method of any one of claims 1 to 3.
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| CN202211368275.1A CN115488483B (en) | 2022-11-03 | 2022-11-03 | Method for improving bonding strength of steel rail flash butt welding joint |
| PCT/CN2023/093540 WO2024093184A1 (en) | 2022-11-03 | 2023-05-11 | Method for improving bonding strength of rail flash-butt welded joint |
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| CN202211368275.1A CN115488483B (en) | 2022-11-03 | 2022-11-03 | Method for improving bonding strength of steel rail flash butt welding joint |
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Citations (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA418002A (en) * | 1944-01-25 | G. Schreiner Norman | Welding means | |
| US4300031A (en) * | 1977-08-05 | 1981-11-10 | Tocco-Stel | Method for induction butt-welding metal parts, in particular parts of irregular cross-section |
| JPH05117826A (en) * | 1991-08-30 | 1993-05-14 | Sumitomo Light Metal Ind Ltd | Manufacture of high strength aluminum alloy-made rim |
| WO2004111340A1 (en) * | 2003-06-13 | 2004-12-23 | Franz Plasser Bahnbaumaschinen- Industriegesellschaft Mbh | Welding unit for welding rail ends of a track |
| JP2008274744A (en) * | 2007-03-30 | 2008-11-13 | Nippon Steel Corp | Long welded rail and manufacturing method for the same |
| CN102971107A (en) * | 2010-05-28 | 2013-03-13 | 铁路发展服务公司 | System and method for flash-welding |
| KR20130050416A (en) * | 2011-11-08 | 2013-05-16 | 주식회사 포스코 | Flash butt welding method of steel sheet |
| CN106334863A (en) * | 2016-10-19 | 2017-01-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for movable flash welding of 75 kg/m hypereutectoid steel rail and pearlite steel rail, and steel rails |
| CN106544933A (en) * | 2016-10-19 | 2017-03-29 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of method that post weld heat treatment is carried out to steel rail weld joint |
| CN107520529A (en) * | 2017-08-31 | 2017-12-29 | 攀钢集团研究院有限公司 | The method that 136RE+SS heat-treated rails move Flash Butt Welding |
| CN107552936A (en) * | 2017-09-07 | 2018-01-09 | 攀钢集团研究院有限公司 | 60kg/mU75V+U75VG rail moves Flash Butt Welding and Technology for Heating Processing |
| CN108149533A (en) * | 2017-12-18 | 2018-06-12 | 中国铁道科学研究院金属及化学研究所 | A kind of method for improving WELDING JOINT intensity |
| CN108890106A (en) * | 2018-07-26 | 2018-11-27 | 攀钢集团攀枝花钢铁研究院有限公司 | The method of the mobile Flash Butt Welding of 60kg/m R260 hot rolled rail |
| CN109079302A (en) * | 2018-08-29 | 2018-12-25 | 攀钢集团攀枝花钢铁研究院有限公司 | The method of the mobile Flash Butt Welding of 60kg/m R260 hot rolled rail |
| CN109986189A (en) * | 2019-05-08 | 2019-07-09 | 西南交通大学 | A kind of technique refining flash welding in rail weld grain |
| CN110102864A (en) * | 2019-04-28 | 2019-08-09 | 铁科（北京）轨道装备技术有限公司 | A kind of welding procedure of steel alloy and groove-shape rail |
| CN110512148A (en) * | 2019-07-31 | 2019-11-29 | 攀钢集团攀枝花钢铁研究院有限公司 | A method of control R260 WELDING JOINT martensitic structure |
| AU2020207808A1 (en) * | 2019-07-31 | 2021-02-18 | Pangang Group Panzhihua Iron & Steel Research Institute Co., Ltd. | A method for controlling the martensitic structure of flash welding joint of r260 steel rail |
| CN113414480A (en) * | 2021-07-23 | 2021-09-21 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for eliminating overburning defect of mobile flash welding head of hypereutectoid steel rail of 75kg/m |
| CN113427109A (en) * | 2021-08-09 | 2021-09-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Welding method of copper-containing corrosion-resistant steel rail |
| CN114054915A (en) * | 2021-11-29 | 2022-02-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Short-circuit preheating flash welding method |
| CN114054916A (en) * | 2021-11-29 | 2022-02-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Gas conveying device and steel rail flash welding method |
-
2022
- 2022-11-03 CN CN202211368275.1A patent/CN115488483B/en active Active
-
2023
- 2023-05-11 WO PCT/CN2023/093540 patent/WO2024093184A1/en unknown
Patent Citations (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA418002A (en) * | 1944-01-25 | G. Schreiner Norman | Welding means | |
| US4300031A (en) * | 1977-08-05 | 1981-11-10 | Tocco-Stel | Method for induction butt-welding metal parts, in particular parts of irregular cross-section |
| JPH05117826A (en) * | 1991-08-30 | 1993-05-14 | Sumitomo Light Metal Ind Ltd | Manufacture of high strength aluminum alloy-made rim |
| WO2004111340A1 (en) * | 2003-06-13 | 2004-12-23 | Franz Plasser Bahnbaumaschinen- Industriegesellschaft Mbh | Welding unit for welding rail ends of a track |
| JP2008274744A (en) * | 2007-03-30 | 2008-11-13 | Nippon Steel Corp | Long welded rail and manufacturing method for the same |
| CN102971107A (en) * | 2010-05-28 | 2013-03-13 | 铁路发展服务公司 | System and method for flash-welding |
| KR20130050416A (en) * | 2011-11-08 | 2013-05-16 | 주식회사 포스코 | Flash butt welding method of steel sheet |
| CN106334863A (en) * | 2016-10-19 | 2017-01-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for movable flash welding of 75 kg/m hypereutectoid steel rail and pearlite steel rail, and steel rails |
| CN106544933A (en) * | 2016-10-19 | 2017-03-29 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of method that post weld heat treatment is carried out to steel rail weld joint |
| CN107520529A (en) * | 2017-08-31 | 2017-12-29 | 攀钢集团研究院有限公司 | The method that 136RE+SS heat-treated rails move Flash Butt Welding |
| CN107552936A (en) * | 2017-09-07 | 2018-01-09 | 攀钢集团研究院有限公司 | 60kg/mU75V+U75VG rail moves Flash Butt Welding and Technology for Heating Processing |
| CN108149533A (en) * | 2017-12-18 | 2018-06-12 | 中国铁道科学研究院金属及化学研究所 | A kind of method for improving WELDING JOINT intensity |
| CN108890106A (en) * | 2018-07-26 | 2018-11-27 | 攀钢集团攀枝花钢铁研究院有限公司 | The method of the mobile Flash Butt Welding of 60kg/m R260 hot rolled rail |
| CN109079302A (en) * | 2018-08-29 | 2018-12-25 | 攀钢集团攀枝花钢铁研究院有限公司 | The method of the mobile Flash Butt Welding of 60kg/m R260 hot rolled rail |
| CN110102864A (en) * | 2019-04-28 | 2019-08-09 | 铁科（北京）轨道装备技术有限公司 | A kind of welding procedure of steel alloy and groove-shape rail |
| CN109986189A (en) * | 2019-05-08 | 2019-07-09 | 西南交通大学 | A kind of technique refining flash welding in rail weld grain |
| CN110512148A (en) * | 2019-07-31 | 2019-11-29 | 攀钢集团攀枝花钢铁研究院有限公司 | A method of control R260 WELDING JOINT martensitic structure |
| AU2020207808A1 (en) * | 2019-07-31 | 2021-02-18 | Pangang Group Panzhihua Iron & Steel Research Institute Co., Ltd. | A method for controlling the martensitic structure of flash welding joint of r260 steel rail |
| CN113414480A (en) * | 2021-07-23 | 2021-09-21 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for eliminating overburning defect of mobile flash welding head of hypereutectoid steel rail of 75kg/m |
| CN113427109A (en) * | 2021-08-09 | 2021-09-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Welding method of copper-containing corrosion-resistant steel rail |
| CN114054915A (en) * | 2021-11-29 | 2022-02-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Short-circuit preheating flash welding method |
| CN114054916A (en) * | 2021-11-29 | 2022-02-18 | 攀钢集团攀枝花钢铁研究院有限公司 | Gas conveying device and steel rail flash welding method |
Non-Patent Citations (1)
| Title |
|---|
| 高速铁路钢轨焊接技术的发展与应用;朱志明;范开果;潘际銮;;焊接;20130525(第05期);第5-10页 * |
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| WO2024093184A1 (en) | 2024-05-10 |
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