CN108660306A - The post weld heat treatment method of hypereutectoid steel rail and eutectoid steel steel rail weld joint - Google Patents
The post weld heat treatment method of hypereutectoid steel rail and eutectoid steel steel rail weld joint Download PDFInfo
- Publication number
- CN108660306A CN108660306A CN201810581145.3A CN201810581145A CN108660306A CN 108660306 A CN108660306 A CN 108660306A CN 201810581145 A CN201810581145 A CN 201810581145A CN 108660306 A CN108660306 A CN 108660306A
- Authority
- CN
- China
- Prior art keywords
- rail
- steel
- steel rail
- cooling
- weld joint
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
- C21D9/505—Cooling thereof
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/009—Pearlite
Abstract
The invention discloses a kind of post weld heat treatment methods of hypereutectoid steel rail and eutectoid steel steel rail weld joint, belong to rail welding technique field.The present invention is in order to solve rail steel rail weld joint " saddle " abrasion and the technical issues of early fatigue fracture caused by welding region lower hardness or Microstructure of Joint exception during circuit military service, provide a kind of post weld heat treatment method of hypereutectoid steel rail and eutectoid steel steel rail weld joint, steel rail weld joint is subjected to the first cooling stage successively, second cooling stage and third cooling stage, and control the cooling velocity and temperature in each stage, so as to improve rail circuit military service during caused by welding region lower hardness or Microstructure of Joint exception steel rail weld joint " saddle " abrasion and early fatigue fracture.
Description
Technical field
The invention belongs to rail welding technique fields, and in particular to a kind of hypereutectoid steel rail connects with eutectoid steel rail welding
The post weld heat treatment method of head.
Background technology
Currently, heavy haul railway circuit mostly uses eutectoid pearlite steel rail both at home and abroad, the phosphorus content of such rail usually exists
Within the scope of 0.72-0.82 weight %, metallographic structure is pearlite, has obdurability matching good, comprehensive mechanical property index is suitable
The features such as middle.With the fast development of railway, big axis weight heavy-haul line proposes requirements at the higher level to rail military service performance, and due to
The comprehensive mechanical property of conventional pearlitic rail has almost developed to the limit with welding performance.In this case, strength grade is more
Height, the hypereutectoid rail for taking into account the comprehensive performances such as good abrasion resistance properties and contact fatigue come into being, such rail it is carbon containing
For amount usually within the scope of 0.90-1.10 weight %, metallographic structure is pearlite+a small amount of secondary cementite.At this stage, rail moves
Flash welding has become the online welding technique of mainstream rail at domestic and international construction of railways scene.For strength grade and material not phase
With two kinds of rail, the difference between base material performance brings huge challenge to its welding.After rail is acted on by Thermal Cycle, weldering
The quench-hardened case for connecing region disappears and the soft area larger in weld seam both sides formation width, leads to the hardness of weld dimensions
Less than rail base material.Rail easily preferentially forms " saddle " abrasion, no during circuit is on active service in the rail head tread of welding point
Wheel-rail impact is increased only, also seriously affects rail service life, or even jeopardize traffic safety.Thus, how to restore rail because
The mechanical property welded and reduced just is able to the premise applied at rail.
Currently, report and document about hypereutectoid steel rail and eutectoid steel rail welding and post weld heat treatment technical study
Data is also relatively fewer.CN201610909362.1 discloses a kind of hypereutectoid rail and PG4 heat treatment eutectoid pearlite steel rails
The post weld heat treatment method of welding point, this method include that will weld obtained steel rail weld joint to be cooled to carry out first cold
But to 400 DEG C hereinafter, the first steel rail weld joint after cooling is then heated to 860-930 DEG C, then progress second cools down
Wheel tread temperature to steel rail weld joint is 410-450 DEG C.The xenogenesis steel rail weld joint obtained using this method can meet state
Interior existing railroad industry standard TB/T1632.2-2014《Rail welding part 2：Flash Butt Welding》In for fatigue, stretch, punching
It hits and the test request of quiet curved experiment；But rail postwelding normalizing heat treatment has been arrived involved in foregoing invention, has needed to use rail
PWHT equipment carries out local heating, operation and implementation process complexity, high expensive to steel rail weld joint.
Invention content
The present invention is in order to solve rail during circuit is on active service because welding region lower hardness or Microstructure of Joint are different
Steel rail weld joint " saddle " abrasion and the technical issues of early fatigue fracture caused by often, provide a kind of hypereutectoid steel steel
The post weld heat treatment method of rail and eutectoid steel steel rail weld joint comprising following steps：The steel to be cooled that welding is obtained
Rail welding point carries out first stage cooling under the first cooling velocity, so that the rail head skin temperature of steel rail weld joint is down to
570~640 DEG C, steel rail weld joint is then set to carry out second stage cooling under the second cooling velocity, so that rail welding connects
The rail head skin temperature of head is down to 410~460 DEG C, and steel rail weld joint is finally made to carry out the phase III under third cooling velocity
It is cooling, so that the rail head skin temperature of steel rail weld joint is down to 10~30 DEG C.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
State steel rail weld joint be by with rail type of the same race hypereutectoid rail and eutectoid rail be welded.
Preferably, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint,
The rail type of the hypereutectoid rail is 60 or 68kg/m, and the rail type of the eutectoid rail is 60 or 68kg/m.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
The initial temperature for stating steel rail weld joint is 1000~1350 DEG C.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
The mode of first stage cooling is stated as natural cooling in air.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
It is 3.0~5.0 DEG C/s to state the first cooling velocity.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
It states second stage cooling and type cooling device is imitated using rail head of rail, using compressed air or water mist gaseous mixture as cooling medium to steel
The rail head tread of rail welding point and rail head side are cooled down, and cooling device is 20~50mm apart from rail head of rail tread；It is cold
But the gas pressure of device is ejected compressed air or water mist gaseous mixture is 0.40~0.80MPa.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
It is 1.5~2.5 DEG C/s to state the second cooling velocity.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
It states phase III cooling and type cooling device is imitated using rail head of rail, using compressed air or water mist gaseous mixture as cooling medium to steel
The rail head tread of rail welding point and rail head side are cooled down, and cooling device is 20~50mm apart from rail head of rail tread；It is cold
But the gas pressure of device is ejected compressed air or water mist gaseous mixture is 0.05~0.25MPa.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
It is 0.05~0.50 DEG C/s to state third cooling velocity.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
The welding point for stating hypereutectoid steel rail and eutectoid steel rail is to move the xenogenesis rail that flash welder is welded using rail
Welding point.
The beneficial effects of the invention are as follows：
The method of the present invention can ensure steel rail weld joint under the premise of the abnormal structures such as martensite-free, bainite,
Meet corresponding eutectoid pearlite steel rail and excessively total respectively away from the rail joint longitudinal direction hardness in the regions Weld pipe mill ± 10mm
Analyse ± 30HV the ranges (axis of a weld for not including decarburization) of rail base material average hardness, and the softening of joint welding both sides
Sector width is below 15mm；Using the present invention help to improve rail during circuit is on active service because of welding region lower hardness or
Steel rail weld joint " saddle " abrasion and early fatigue fracture caused by Microstructure of Joint exception.
Description of the drawings
Fig. 1 is that the hypereutectoid rail under the conditions of the post weld heat treatment obtained using the method in embodiment 1 analyses pearly-lustre together
Longitudinal stiffening effect figure of the positions 3-5mm below the rail head tread of body steel rail weld joint.
Fig. 2 is to analyse pearl together using the hypereutectoid rail under the conditions of the obtained post weld heat treatment of method in embodiment 2
Longitudinal stiffening effect figure of the positions 3-5mm below the rail head tread of body of light steel rail weld joint.
Fig. 3 is to analyse pearly-lustre together using hypereutectoid rail of the obtained postwelding of method in comparative example 1 under the conditions of air-cooled
Longitudinal stiffening effect figure of the positions 3-5mm below the rail head tread of body steel rail weld joint.
Fig. 4 is to analyse pearl together using the hypereutectoid rail under the conditions of the obtained post weld heat treatment of method in comparative example 2
Longitudinal stiffening effect figure of the positions 3-5mm below the rail head tread of body of light steel rail weld joint.
Fig. 5 is to analyse pearl together using the hypereutectoid rail under the conditions of the obtained post weld heat treatment of method in comparative example 3
Longitudinal stiffening effect figure of the positions 3-5mm below the rail head tread of body of light steel rail weld joint.
Fig. 6 is to analyse pearl together using the hypereutectoid rail under the conditions of the obtained post weld heat treatment of method in comparative example 4
Longitudinal stiffening effect figure of the positions 3-5mm below the rail head tread of body of light steel rail weld joint.
Fig. 7 is longitudinal hardness determination schematic diagram of the rail head tread of the steel rail weld joint of the present invention or less the positions 3-5mm.
Fig. 8 is the rail head tread metallographic specimen sample position schematic diagram of the rail joint of the present invention.
Specific implementation mode
The post weld heat treatment method of hypereutectoid steel rail and eutectoid steel steel rail weld joint, includes the following steps：It will welding
Obtained steel rail weld joint to be cooled carries out first stage cooling under the first cooling velocity, so that steel rail weld joint
Rail head skin temperature is down to 570~640 DEG C, so that steel rail weld joint is carried out second stage under the second cooling velocity cold
But, so that the rail head skin temperature of steel rail weld joint is down to 410~460 DEG C, steel rail weld joint is finally made to be cooled down in third
Phase III cooling is carried out under speed, so that the rail head skin temperature of steel rail weld joint is down to 10~30 DEG C.
About 0.7~1.5 DEG C/s of critical cooling rate of martensite transfor mation during eutectoid rail steel continuous cooling transformation,
And about 1.8~3.0 DEG C/s of critical cooling rate of the martensite transfor mation during hypereutectoid steel rail steel continuous cooling transformation；Eutectoid
About 250 DEG C of pearlite steel rail Ms temperature (start temperature that martensitic structure is formed), and about 190 DEG C of hypereutectoid rail Ms temperature.
To avoid steel rail weld joint from the abnormal structures such as martensite occur, when to the welding point of hypereutectoid steel rail and eutectoid steel rail
When carrying out post weld heat treatment, the final cooling temperature during need to being quickly cooled down post weld heat treatment is controlled in eutectoid pearlite steel rail Ms
It is more than temperature；Meanwhile the cooling velocity in PWHT procedures must be with the relatively low eutectoid pearlite steel rail of Critical cooling speed
Steel is limited, and otherwise connector will cause premature fatigue to be broken due to the martensitic structure hardened.In addition, hypereutectoid rail base material
In there is also a small amount of secondary cementite, be in netted Intergranular precipitation during rail welding to avoid secondary cementite, therefore palpus
Butt joint implementation is quickly cooled down before austenite starts to perlitic transformation.Based on above-mentioned discovery, inventor completes the present invention.
In the present invention, it is cold to implement postwelding acceleration for the rail joint for welding obtained residual temperature higher (1000~1350 DEG C)
But, to reduce phase transition temperature of the connector rail head from austenite to perlitic transformation, to improve the hardness in austenite recrystallization area.
Based on Principles of Metallography, rail joint, there are certain dynamic degree of supercooling, causes non-flat under postwelding high temperature condition of fast cooling
Austenite is moved down to the phase transition temperature of perlitic transformation under weighing apparatus state, and with the increase of degree of supercooling, and phase transition temperature continuously decreases.
Thus, even if opening the relatively low second stage cooling of cold temperature, connector rail head remains to occur from austenite to pearlite
Structural transformation.
In the present invention, the first cold stage is but the natural cooling (can carry out at room temperature) carried out in air, cold
But speed is 3.0~5.0 DEG C/s, can be realized to the first stage (as used central air-conditioner temperature control) by adjusting test ambient temperature
The control of cooling velocity, and can be by adjusting the end that welding machine is arranged or manual operation cools down the steel rail weld joint first stage
Cold temperature control is at 570~640 DEG C；The cold temperature of opening of the second stage cooling is 570~640 DEG C, it is notable that this
In invention, the final cooling temperature of the second stage cooling turns higher than the martensite of hypereutectoid steel rail steel and eutectoid pearlite steel rail steel
Become start temperature (Ms temperature), the present invention in the second cooling stage final cooling temperature be 410~460 DEG C, cooling velocity be 1.5~
2.5℃/s；When carrying out phase III cooling to rail joint, for the martensitic structure for avoiding connector from occurring hardening, the present invention
Selection is with real less than 0.05~0.50 DEG C/s of the cooling velocity butt joints of eutectoid pearlite steel rail steel martensite transfor mation Critical cooling speed
It applies and cools down at a slow speed, and be cooled to room temperature (10~30 DEG C)；The type of cooling that the present invention is cooled down by using three steps, limitation are different cold
But the cooling velocity and cooling temperature in stage can reach and promote steel rail weld joint hardness, ensure in steel rail weld joint metallographic
The purpose of the abnormal structures such as martensite-free, bainite.
In the method for the present invention, the second stage cooling and phase III cooling imitate type cooling device using rail head of rail,
The rail head tread of steel rail weld joint and rail head side are cooled down as cooling medium using compressed air or water mist gaseous mixture,
Cooling device is 20~50mm apart from rail head of rail tread；The compressed air or water that the second stage cooling device is ejected
The gas pressure of mist gaseous mixture is 0.40~0.80MPa, the compressed air or water that the phase III cooling device is ejected
The gas pressure of mist gaseous mixture is 0.05~0.25MPa.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
It states third cooling velocity and is far below second cooling velocity.
Wherein, in the post weld heat treatment method of hypereutectoid steel rail described above and eutectoid steel steel rail weld joint, institute
The welding point for stating hypereutectoid steel rail and eutectoid steel rail is to move the xenogenesis rail that flash welder is welded using rail
Welding point.
In the present invention, hypereutectoid rail and eutectoid rail for welding are specification of the same race, specially 60 or 68kg/m
Specification, the steel rail weld joint is to be connect by the welding that is welded of rail movement flash welder using same welding procedure
Head.
In the present invention, in the absence of explanation to the contrary, " steel rail weld joint " be it is welded obtain include
Length including weld seam and/or heat affected area is the region of 70~100mm ranges, and the center in the region is the weld seam of rail.
In the present invention, the temperature signal of rail head of rail tread is acquired using infrared radiation thermometer, the rail head of rail tread is
The contact portion of wheel and rail；The hardness number corresponding to softened zone width measurement line in the hardness curve of rail joint longitudinal direction is
Rail base material average hardness subtracts the hardness after 25HV；Softening sector width in hardness curve is hardness curve and softening sector width
Measure the intercept of line.
Below by embodiment, invention is further described in detail, but does not therefore limit the scope of the present invention
Among the embodiment described range.
The welding point of the embodiment of the present invention and comparative example is 68kg/m hypereutectoid rail and 68kg/m eutectoid rail weldings
Connector.
When the embodiment of the present invention and comparative example carry out steel rail weld joint Hardness Surveillance, welding point vertical section hardness specimens
Sample position sees that Fig. 7, weld seam are located at specimen length center, tests the hardness number of steel rail weld joint vertical section, measuring point is with weld seam
Centered on to the left and right both sides be symmetrically arranged, measuring point spacing 2mm；Welding point vertical section detects Vickers hardness, and test method presses GB/
T4340.1-2009 regulations carry out, experiment force value 294.2N；Recrystallization zone is apart from the region of Weld pipe mill ± 10mm；Hardness is examined
Survey should cover welding point whole region, including base material, heat affected area, weld seam, extend to welding point per side rail base material
The region of 20mm.
Embodiment 1
After rail completes the upset during mobile Flash Butt Welding and pushes away tumor, the connector that welding obtains is carried out at postwelding heat
Reason.First, residual temperature welding obtained carries out the first stage in 1100 DEG C of rail joint with the first cooling velocity of 4.0 DEG C/s
Cooling then makes rail joint with the second cooling velocity of 2.0 DEG C/s so that the rail head skin temperature of rail joint is down to 630 DEG C
Second stage cooling is carried out so that the rail head skin temperature of rail joint is down to 450 DEG C, finally makes rail joint with 0.4 DEG C/s's
Third cooling velocity carries out phase III cooling the rail head skin temperature of rail joint to be down to 25 DEG C of room temperature, to obtain
The steel rail weld joint through post weld heat treatment of the present invention；
In PWHT procedures, first is cooled to the natural cooling carried out in air；Second cooling and third cooling
Rail head of rail is used to imitate rail head tread and rail of the type cooling device using compressed air as cooling medium to rail joint in the process
Rostral face is cooled down, and cooling device is apart from rail head of rail tread 40mm；In second cooling procedure, the compression of cooling device injection
The gas pressure of air is 0.60MPa；In third cooling procedure, the gas pressure of the compressed air of cooling device injection is
0.20MPa.Rail head of rail wheel tread temperature is monitored using infrared radiation thermometer.
The rail joint through post weld heat treatment that the present embodiment obtains is machined to longitudinal hardness specimens.It is hard using cloth dimension
Degree meter positions 4mm below rail head of rail tread (Laizhou, Shandong city testing machine head factory, model HBV-30A), using 2mm between measuring point
Away from longitudinal Vickers hardness detection is carried out to hardness specimens, both sides are symmetrically arranged measuring point to the left and right centered on weld seam.Vickers hardness
The method of inspection is with reference to GB/T 4340.1-2009《Vickers Hardness Test part 1：Test method》It carries out, is marked using HV
Ruler.Hardness Surveillance data are shown in Table 1, and the distributed effect of connector longitudinal direction hardness is as shown in Figure 1.
1 embodiment of table, 1 steel rail weld joint Hardness Surveillance data
By table 1 and Fig. 1 it is found that for steel rail weld joint processed by the invention, away from the regions Weld pipe mill ± 10mm
Interior rail joint longitudinal direction hardness meets corresponding eutectoid pearlite steel rail and hypereutectoid rail base material average hardness respectively
± 30HV ranges (do not include the axis of a weld of decarburization：It is influenced by rail welding high temperature, Weld pipe mill decarburization simultaneously generates first biscuiting
Damage, leads to lower hardness).The softening sector width of joint welding eutectoid pearlite steel rail side is 10mm, hypereutectoid rail side
Softening sector width be 8mm, the softening sector width of joint welding both sides is below 15mm.
GB/T13298-2015 is pressed with reference to sampling method shown in Fig. 8《The metal microstructure method of inspection》To rail joint
Metallographic specimen carries out microstructure examination, carries out etch to rail joint metallographic specimen using 3% nital, using moral
State comes card MeF3 light microscopes and observes rail joint metallographic structure.The result shows that connector metallographic martensite-free, bayesian
Ti Deng abnormal structures.
Embodiment 2
After rail completes the upset during mobile Flash Butt Welding and pushes away tumor, the connector that welding obtains is carried out at postwelding heat
Reason.First, residual temperature welding obtained carries out the first stage in 1000 DEG C of rail joint with the first cooling velocity of 5.0 DEG C/s
Cooling then makes rail joint with the second cooling velocity of 2.2 DEG C/s so that the rail head skin temperature of rail joint is down to 610 DEG C
Second stage cooling is carried out so that the rail head skin temperature of rail joint is down to 440 DEG C, finally makes rail joint with 0.10 DEG C/s
Third cooling velocity carry out the phase III cool down the rail head skin temperature of rail joint to be down to 25 DEG C of room temperature, to
To the heterogeneous material steel rail weld joint through post weld heat treatment of the present invention；
In PWHT procedures, first is cooled to the natural cooling carried out in air；Second cooling and third cooling
In the process, use rail head of rail imitate type cooling device using water mist gaseous mixture as cooling medium to the rail head tread of rail joint and
Rail head side is cooled down, and cooling device is apart from rail head of rail tread 40mm；In second cooling procedure, the water of cooling device injection
The gas pressure of mist gaseous mixture is 0.65MPa；In third cooling procedure, the gas pressure of the water mist gaseous mixture of cooling device injection
For 0.09MPa.Rail head of rail wheel tread temperature is monitored using infrared radiation thermometer.
The rail joint through post weld heat treatment that the present embodiment obtains is machined to longitudinal hardness specimens.It is hard using cloth dimension
Degree meter positions 4mm below rail head of rail tread (Laizhou, Shandong city testing machine head factory, model HBV-30A), using 2mm between measuring point
Away from longitudinal Vickers hardness detection is carried out to hardness specimens, both sides are symmetrically arranged measuring point to the left and right centered on weld seam.Vickers hardness
The method of inspection is with reference to GB/T 4340.1-2009《Vickers Hardness Test part 1：Test method》It carries out, is marked using HV
Ruler.Hardness Surveillance data are shown in Table 2, and the distributed effect of connector longitudinal direction hardness is as shown in Figure 2.
2 embodiment of table, 2 steel rail weld joint Hardness Surveillance data
By table 2 and Fig. 2 it is found that for steel rail weld joint processed by the invention, away from the regions Weld pipe mill ± 10mm
Interior rail joint longitudinal direction hardness meets corresponding eutectoid pearlite steel rail and hypereutectoid rail base material average hardness respectively
± 30HV ranges (do not include the axis of a weld of decarburization：It is influenced by rail welding high temperature, Weld pipe mill decarburization simultaneously generates first biscuiting
Damage, leads to lower hardness).The softening sector width of joint welding eutectoid pearlite steel rail side is 8mm, hypereutectoid rail side
Softening sector width is 8mm, and the softening sector width of joint welding both sides is below 15mm.
GB/T13298-2015 is pressed with reference to sampling method shown in Fig. 8《The metal microstructure method of inspection》To rail joint
Metallographic specimen carries out microstructure examination, carries out etch to rail joint metallographic specimen using 3% nital, using moral
State comes card MeF3 light microscopes and observes rail joint metallographic structure.The result shows that connector metallographic martensite-free, bayesian
Ti Deng abnormal structures.
Comparative example 1
It is after rail completes the upset during mobile Flash Butt Welding and pushes away tumor, residual temperature is direct in 1000 DEG C of rail joint
It is air-cooled to room temperature (about 25 DEG C), to obtain the steel rail weld joint under the conditions of air-cooled (natural cooling).
Rail joint under the conditions of taking the postwelding that this comparative example obtains air-cooled is processed into longitudinal hardness specimens.It is hard using cloth dimension
Degree meter positions 5mm below rail head of rail tread (Laizhou, Shandong city testing machine head factory, model HBV-30A), using 2mm between measuring point
Away from longitudinal Vickers hardness detection is carried out to hardness specimens, both sides are symmetrically arranged measuring point to the left and right centered on weld seam.Vickers hardness
The method of inspection is with reference to GB/T 4340.1-2009《Vickers Hardness Test part 1：Test method》It carries out, is marked using HV
Ruler.Hardness Surveillance data are shown in Table 3, and the distributed effect of connector longitudinal direction hardness is as shown in Figure 3.
3 comparative example of table, 1 steel rail weld joint Hardness Surveillance data
By table 3 and Fig. 3 it is found that for not connect using the rail welding of post weld heat treatment method provided by the invention processing
Head, compared with the rail base material hardness of weld seam both sides, entire welding region is rendered as soft state.Away from Weld pipe mill ± 10mm
It is average with hypereutectoid rail base material that rail joint longitudinal direction hardness in region cannot meet corresponding eutectoid pearlite steel rail
± 30HV the ranges of hardness (do not include the axis of a weld of decarburization：It is influenced by rail welding high temperature, Weld pipe mill decarburization simultaneously generates
Melting loss of elements leads to lower hardness).The softening sector width of joint welding eutectoid pearlite steel rail side is 8mm, hypereutectoid rail
The softening sector width of side is 18mm.The welding point obtained by the comparative example is during circuit is on active service, easily preferentially in connector
The softened zone of weld seam hypereutectoid rail side forms that rail head of rail tread is low to collapse, and influences Track regularity and traffic safety.
GB/T13298-2015 is pressed with reference to sampling method shown in Fig. 8《The metal microstructure method of inspection》To rail joint
Metallographic specimen carries out microstructure examination, carries out etch to rail joint metallographic specimen using 3% nital, using moral
State comes card MeF3 light microscopes and observes rail joint metallographic structure.The result shows that connector metallographic structure is normal, no horse
The abnormal structures such as family name's body, bainite.
Comparative example 2
After rail completes the upset during mobile Flash Butt Welding and pushes away tumor, the connector that welding obtains is carried out at postwelding heat
Reason.First, residual temperature welding obtained carries out the first stage in 1100 DEG C of rail joint with the first cooling velocity of 5.0 DEG C/s
Cooling then makes rail joint with the second cooling velocity of 3.0 DEG C/s so that the rail head skin temperature of rail joint is down to 620 DEG C
Second stage cooling is carried out so that the rail head skin temperature of rail joint is down to 220 DEG C, finally makes rail joint with 0.10 DEG C/s
Third cooling velocity carry out the phase III cool down the rail head skin temperature of rail joint to be down to 25 DEG C of room temperature, to
To the heterogeneous material steel rail weld joint through post weld heat treatment of the present invention；
In PWHT procedures, first is cooled to the natural cooling carried out in air；Second cooling and third cooling
In the process, rail head of rail is used to imitate rail head tread and rail of the type cooling device using compressed air as cooling medium to rail joint
Rostral face is cooled down, and cooling device is apart from rail head of rail tread 40mm；In second cooling procedure, the compression of cooling device injection
The gas pressure of air is 0.90MPa；In third cooling procedure, the gas pressure of the compressed air of cooling device injection is
0.09MPa.Rail head of rail wheel tread temperature is monitored using infrared radiation thermometer.
Rail joint under the conditions of taking the postwelding that this comparative example obtains air-cooled is processed into longitudinal hardness specimens.It is hard using cloth dimension
Degree meter positions 4mm below rail head of rail tread (Laizhou, Shandong city testing machine head factory, model HBV-30A), using 2mm between measuring point
Away from longitudinal Vickers hardness detection is carried out to hardness specimens, both sides are symmetrically arranged measuring point to the left and right centered on weld seam.Vickers hardness
The method of inspection is with reference to GB/T 4340.1-2009《Vickers Hardness Test part 1：Test method》It carries out, is marked using HV
Ruler.Hardness Surveillance data are shown in Table 4, and the distributed effect of connector longitudinal direction hardness is as shown in Figure 4.
4 comparative example of table, 2 steel rail weld joint Hardness Surveillance data
By table 4 and Fig. 4 it is found that for not connect using the rail welding of post weld heat treatment method provided by the invention processing
The softening sector width of head, obtained connector eutectoid rail side is 10mm, and the softening sector width of hypereutectoid rail side is
10mm.Joint welding eutectoid pearlite steel rail side hardness is higher, and the hardness away from the positions Weld pipe mill 2mm reaches 475HV, exceeds
Eutectoid pearlite steel rail base material average hardness 35HV.Such connector is during circuit is on active service, due to joint welding hypereutectoid steel
Rail side hardness is relatively low, easily preferentially forms that rail head of rail tread is low collapses in the side softened zone, and connector " saddle " is caused to wear away,
Influence Track regularity.
GB/T13298-2015 is pressed with reference to sampling method shown in Fig. 8《The metal microstructure method of inspection》To rail joint
Metallographic specimen carries out microstructure examination, carries out etch to rail joint metallographic specimen using 3% nital, using moral
State comes card MeF3 light microscopes and observes rail joint metallographic structure.The result shows that connector hypereutectoid rail and eutectoid
There is the martensitic structure hardened in pearlite steel rail, and influences circuit operational safety.
Comparative example 3
After rail completes the upset during mobile Flash Butt Welding and pushes away tumor, the connector that welding obtains is carried out at postwelding heat
Reason.First, residual temperature welding obtained carries out the first stage in 1050 DEG C of rail joint with the first cooling velocity of 4.5 DEG C/s
Cooling then makes rail joint with the second cooling velocity of 2.2 DEG C/s so that the rail head skin temperature of rail joint is down to 620 DEG C
Second stage cooling is carried out so that the rail head skin temperature of rail joint is down to 440 DEG C, finally makes rail joint with 2.5 DEG C/s's
Third cooling velocity carries out phase III cooling the rail head skin temperature of rail joint to be down to 25 DEG C of room temperature, to obtain
The heterogeneous material steel rail weld joint through post weld heat treatment of the present invention；
In PWHT procedures, first is cooled to the natural cooling carried out in air；Second cooling and third cooling
In the process, rail head of rail is used to imitate rail head tread and rail of the type cooling device using compressed air as cooling medium to rail joint
Rostral face is cooled down, and cooling device is apart from rail head of rail tread 40mm；In second cooling procedure, the compression of cooling device injection
The gas pressure of air is 0.65MPa；In third cooling procedure, the gas pressure of the compressed air of cooling device injection is
0.80MPa.Rail head of rail wheel tread temperature is monitored using infrared radiation thermometer.
Rail joint under the conditions of taking the postwelding that this comparative example obtains air-cooled is processed into longitudinal hardness specimens.It is hard using cloth dimension
Degree meter positions 4mm below rail head of rail tread (Laizhou, Shandong city testing machine head factory, model HBV-30A), using 2mm between measuring point
Away from longitudinal Vickers hardness detection is carried out to hardness specimens, both sides are symmetrically arranged measuring point to the left and right centered on weld seam.Vickers hardness
The method of inspection is with reference to GB/T4340.1-2009《Vickers Hardness Test part 1：Test method》It carries out, using HV scales.
Hardness Surveillance data are shown in Table 5, and the distributed effect of connector longitudinal direction hardness is as shown in Figure 5.
5 comparative example of table, 3 steel rail weld joint Hardness Surveillance data
By table 5 and Fig. 5 it is found that for not connect using the rail welding of post weld heat treatment method provided by the invention processing
The softening sector width of head, obtained connector eutectoid rail side is 12mm, and the softening sector width of hypereutectoid rail side is
10mm.Joint welding eutectoid pearlite steel rail side hardness is higher, exceeds eutectoid pearl away from the hardness at Weld pipe mill ± 10mm
Body of light rail and hypereutectoid rail base material average hardness 30HV.Such connector is during circuit is on active service, due to joint welding mistake
Eutectoid rail side hardness is relatively low, easily preferentially forms that rail head of rail tread is low collapses in the side softened zone, causes connector " saddle
Type " is worn away, and influences Track regularity.
GB/T13298-2015 is pressed with reference to sampling method shown in Fig. 8《The metal microstructure method of inspection》To rail joint
Metallographic specimen carries out microstructure examination, carries out etch to rail joint metallographic specimen using 3% nital, using moral
State comes card MeF3 light microscopes and observes rail joint metallographic structure.The result shows that joint welding hypereutectoid rail one
Occur the martensitic structure hardened in the metallographic of side, influences circuit operational safety.
Comparative example 4
After rail completes the upset during mobile Flash Butt Welding and pushes away tumor, the connector that welding obtains is carried out at postwelding heat
Reason.First, residual temperature welding obtained carries out the first stage in 1050 DEG C of rail joint with the first cooling velocity of 4.5 DEG C/s
Cooling then makes rail joint with the second cooling velocity of 2.2 DEG C/s so that the rail head skin temperature of rail joint is down to 620 DEG C
Second stage cooling is carried out so that the rail head skin temperature of rail joint is down to 440 DEG C, finally makes rail joint with 3.5 DEG C/s's
Third cooling velocity carries out phase III cooling the rail head skin temperature of rail joint to be down to 20 DEG C of room temperature, to obtain
The heterogeneous material steel rail weld joint through post weld heat treatment of the present invention；
In PWHT procedures, first is cooled to the natural cooling carried out in air；Second cooling and third cooling
In the process, use rail head of rail imitate type cooling device using water mist gaseous mixture as cooling medium to the rail head tread of rail joint and
Rail head side is cooled down, and cooling device is apart from rail head of rail tread 40mm；In second cooling procedure, the water of cooling device injection
The gas pressure of mist gaseous mixture is 0.65MPa；In third cooling procedure, the gas pressure of the water mist gaseous mixture of cooling device injection
For 1.10MPa.Rail head of rail wheel tread temperature is monitored using infrared radiation thermometer.
Rail joint under the conditions of taking the postwelding that this comparative example obtains air-cooled is processed into longitudinal hardness specimens.It is hard using cloth dimension
Degree meter positions 4mm below rail head of rail tread (Laizhou, Shandong city testing machine head factory, model HBV-30A), using 2mm between measuring point
Away from longitudinal Vickers hardness detection is carried out to hardness specimens, both sides are symmetrically arranged measuring point to the left and right centered on weld seam.Vickers hardness
The method of inspection is with reference to GB/T 4340.1-2009《Vickers Hardness Test part 1：Test method》It carries out, is marked using HV
Ruler.Hardness Surveillance data are shown in Table 6, and the distributed effect of connector longitudinal direction hardness is as shown in Figure 6.
6 comparative example of table, 4 steel rail weld joint Hardness Surveillance data
By table 6 and Fig. 6 it is found that for not connect using the rail welding of post weld heat treatment method provided by the invention processing
The softening sector width of head, obtained connector eutectoid rail side is 8mm, and the softening sector width of hypereutectoid rail side is
10mm.Joint welding eutectoid pearlite steel rail is not much different with hypereutectoid rail hardness.For eutectoid pearlite steel rail, away from weld seam
The hardness of the center positions 10mm is only 350HV, lower 90HV than eutectoid pearlite steel rail base material average hardness.
GB/T13298-2015 is pressed with reference to sampling method shown in Fig. 8《The metal microstructure method of inspection》To rail joint
Metallographic specimen carries out microstructure examination, carries out etch to rail joint metallographic specimen using 3% nital, using moral
State comes card MeF3 light microscopes and observes rail joint metallographic structure.The result shows that joint welding eutectoid pearlite steel
There is the martensitic structure hardened in rail and hypereutectoid rail metallographic, influences circuit operational safety.
It can be seen that by welding point rail head tread longitudinal direction hardness in comparison diagram 1 to Fig. 6 and welding joint softened sector width：
Pearlite steel rail welding point is analysed for hypereutectoid rail using post weld heat treatment method provided by the invention together and implements postwelding
Heat treatment can make meeting corresponding eutectoid pearly-lustre respectively away from the rail joint longitudinal direction hardness in the regions Weld pipe mill ± 10mm
± 30HV the ranges (axis of a weld for not including decarburization) of body rail and hypereutectoid rail base material average hardness, and connector welds
The softening sector width of seam both sides is below 15mm.Meanwhile the abnormal structures such as martensite-free, bainite in welding point metallographic, have
Conducive to guarantee circuit traffic safety.
The preferred embodiment of the present invention has been described above in detail, although being described according to this hair with reference to specific embodiment
Bright Post-Welding Heattreatment of Rail method, it will be recognized to those skilled in the art that in the thought and range for not departing from the present invention
In the case of, herein various modifications and combinations can be made to the present invention.
Claims (10)
1. the post weld heat treatment method of hypereutectoid steel rail and eutectoid steel steel rail weld joint, it is characterised in that：Including following step
Suddenly：The steel rail weld joint to be cooled that welding obtains is subjected to first stage cooling under the first cooling velocity, so that rail
The rail head skin temperature of welding point is down to 570~640 DEG C, and steel rail weld joint is then made to carry out under the second cooling velocity
Two-stage chilling finally makes steel rail weld joint exist so that the rail head skin temperature of steel rail weld joint is down to 410~460 DEG C
Phase III cooling is carried out under third cooling velocity, so that the rail head skin temperature of steel rail weld joint is down to 10~30 DEG C.
2. the post weld heat treatment method of hypereutectoid steel rail according to claim 1 and eutectoid steel steel rail weld joint,
It is characterized in that：The steel rail weld joint be by with rail type of the same race hypereutectoid rail and eutectoid rail be welded.
3. the post weld heat treatment method of hypereutectoid steel rail according to claim 1 and eutectoid steel steel rail weld joint,
It is characterized in that：The initial temperature of the steel rail weld joint is 1000~1350 DEG C.
4. the post weld heat treatment method of hypereutectoid steel rail according to claim 1 and eutectoid steel steel rail weld joint,
It is characterized in that：The mode of the first stage cooling is natural cooling in air.
5. the post weld heat treatment method of hypereutectoid steel rail according to claim 1 and eutectoid steel steel rail weld joint,
It is characterized in that：First cooling velocity is 3.0~5.0 DEG C/s.
6. the post weld heat treatment method of hypereutectoid steel rail according to claim 1 and eutectoid steel steel rail weld joint,
It is characterized in that：Second stage cooling imitates type cooling device using rail head of rail, using compressed air or water mist gaseous mixture as
Cooling medium cools down the rail head tread of steel rail weld joint and rail head side, and cooling device is apart from rail head of rail tread
20~50mm；The gas pressure of compressed air or water mist gaseous mixture that cooling device is ejected is 0.40~0.80MPa.
7. the post weld heat treatment method of hypereutectoid steel rail according to claim 6 and eutectoid steel steel rail weld joint,
It is characterized in that：Second cooling velocity is 1.5~2.5 DEG C/s.
8. the post weld heat treatment method of hypereutectoid steel rail according to claim 1 and eutectoid steel steel rail weld joint,
It is characterized in that：Phase III cooling imitates type cooling device using rail head of rail, using compressed air or water mist gaseous mixture as
Cooling medium cools down the rail head tread of steel rail weld joint and rail head side, and cooling device is apart from rail head of rail tread
20~50mm；The gas pressure of compressed air or water mist gaseous mixture that cooling device is ejected is 0.05~0.25MPa.
9. the post weld heat treatment method of hypereutectoid steel rail according to claim 8 and eutectoid steel steel rail weld joint,
It is characterized in that：The third cooling velocity is 0.05~0.50 DEG C/s.
10. according at the postwelding heat of claim 1~9 any one of them hypereutectoid steel rail and eutectoid steel steel rail weld joint
Reason method, it is characterised in that：The welding point of the hypereutectoid steel rail and eutectoid steel rail is to move flash welding using rail
The welding point for the xenogenesis rail that machine is welded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810581145.3A CN108660306B (en) | 2018-06-07 | 2018-06-07 | Postweld heat treatment method for hypereutectoid steel rail and eutectoid steel rail welded joint |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810581145.3A CN108660306B (en) | 2018-06-07 | 2018-06-07 | Postweld heat treatment method for hypereutectoid steel rail and eutectoid steel rail welded joint |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108660306A true CN108660306A (en) | 2018-10-16 |
| CN108660306B CN108660306B (en) | 2020-07-07 |
Family
ID=63775616
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810581145.3A Active CN108660306B (en) | 2018-06-07 | 2018-06-07 | Postweld heat treatment method for hypereutectoid steel rail and eutectoid steel rail welded joint |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108660306B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109022750A (en) * | 2018-10-26 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The post weld heat treatment method of rail |
| CN110016544A (en) * | 2019-05-28 | 2019-07-16 | 攀钢集团攀枝花钢铁研究院有限公司 | Construction method for the heat treatment of bainite rail postwelding connector |
| CN112251592A (en) * | 2020-10-23 | 2021-01-22 | 攀钢集团攀枝花钢铁研究院有限公司 | Construction method for heat treatment of dissimilar steel rail flash welded joint |
| CN112251587A (en) * | 2020-10-23 | 2021-01-22 | 攀钢集团攀枝花钢铁研究院有限公司 | Heat treatment method for welded joint of bainite steel rail and eutectoid pearlite 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 |
| CN113755670A (en) * | 2021-08-24 | 2021-12-07 | 中铁宝桥集团有限公司 | Quenching and cooling method for bainitic steel frog point rail |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09316598A (en) * | 1996-03-27 | 1997-12-09 | Nippon Steel Corp | Pearlitic rail, excellent in wear resistance and weldability, and its production |
| JP2004043862A (en) * | 2002-07-10 | 2004-02-12 | Nippon Steel Corp | Heat treatment method of pearlitic rail for improving toughness of welded joint |
| CN102985574A (en) * | 2010-06-07 | 2013-03-20 | 新日铁住金株式会社 | Steel rail and production method thereof |
| CN103160736A (en) * | 2011-12-14 | 2013-06-19 | 鞍钢股份有限公司 | High strength bainitic steel rail and heat treatment process thereof |
| CN106086370A (en) * | 2016-06-24 | 2016-11-09 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of method reducing rail residual stress and gained rail and application thereof |
| 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 |
-
2018
- 2018-06-07 CN CN201810581145.3A patent/CN108660306B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09316598A (en) * | 1996-03-27 | 1997-12-09 | Nippon Steel Corp | Pearlitic rail, excellent in wear resistance and weldability, and its production |
| JP2004043862A (en) * | 2002-07-10 | 2004-02-12 | Nippon Steel Corp | Heat treatment method of pearlitic rail for improving toughness of welded joint |
| CN102985574A (en) * | 2010-06-07 | 2013-03-20 | 新日铁住金株式会社 | Steel rail and production method thereof |
| CN103160736A (en) * | 2011-12-14 | 2013-06-19 | 鞍钢股份有限公司 | High strength bainitic steel rail and heat treatment process thereof |
| CN106086370A (en) * | 2016-06-24 | 2016-11-09 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of method reducing rail residual stress and gained rail and application thereof |
| 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 |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109022750A (en) * | 2018-10-26 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | The post weld heat treatment method of rail |
| CN110016544A (en) * | 2019-05-28 | 2019-07-16 | 攀钢集团攀枝花钢铁研究院有限公司 | Construction method for the heat treatment of bainite rail postwelding connector |
| CN112251592A (en) * | 2020-10-23 | 2021-01-22 | 攀钢集团攀枝花钢铁研究院有限公司 | Construction method for heat treatment of dissimilar steel rail flash welded joint |
| CN112251587A (en) * | 2020-10-23 | 2021-01-22 | 攀钢集团攀枝花钢铁研究院有限公司 | Heat treatment method for welded joint of bainite steel rail and eutectoid pearlite steel rail |
| CN112251592B (en) * | 2020-10-23 | 2022-03-22 | 攀钢集团攀枝花钢铁研究院有限公司 | Construction method for heat treatment of dissimilar steel rail flash welded joint |
| CN112251587B (en) * | 2020-10-23 | 2022-03-22 | 攀钢集团攀枝花钢铁研究院有限公司 | Heat treatment method for welded joint of bainite steel rail and eutectoid pearlite 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 |
| CN113755670A (en) * | 2021-08-24 | 2021-12-07 | 中铁宝桥集团有限公司 | Quenching and cooling method for bainitic steel frog point rail |
| CN113755670B (en) * | 2021-08-24 | 2022-10-25 | 中铁宝桥集团有限公司 | Quenching and cooling method for bainitic steel frog point rail |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108660306B (en) | 2020-07-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108504848A (en) | The heat treatment method of WELDING JOINT | |
| CN108754114A (en) | The heat treatment method of steel rail weld joint | |
| CN108660306A (en) | The post weld heat treatment method of hypereutectoid steel rail and eutectoid steel steel rail weld joint | |
| CN108796202A (en) | The heat treatment method of heterogeneous material steel rail weld joint | |
| CN110358906A (en) | The heat treatment method of steel rail weld joint | |
| CN108823394A (en) | Post-Welding Heattreatment of Rail method | |
| CN110016546A (en) | Construction method for the heat treatment of bainite rail postwelding connector | |
| CN110358905A (en) | The heat treatment method of steel rail weld joint | |
| AU2018214003B2 (en) | Post-weld heat treatment method for welded joints of bainitic rails | |
| CN108950158A (en) | Eutectoid rail and hypereutectoid steel rail weld joint heat treatment method | |
| CN106544933A (en) | A kind of method that post weld heat treatment is carried out to steel rail weld joint | |
| CN109355481A (en) | Groove-shape rail flash welding connector post weld heat treatment method | |
| CN109022750A (en) | The post weld heat treatment method of rail | |
| CN110016544A (en) | Construction method for the heat treatment of bainite rail postwelding connector | |
| CN109355482A (en) | The post weld heat treatment method of hypo eutectoid rail | |
| CN107502730A (en) | The post weld heat treatment method of 136RE+SS heat-treated rail welding points | |
| CN112251587B (en) | Heat treatment method for welded joint of bainite steel rail and eutectoid pearlite steel rail | |
| CN109055708A (en) | A kind of eutectoid rail and hypereutectoid steel rail weld joint heat treatment method | |
| CN110331275A (en) | Bainite rail post weld heat treatment method | |
| CN110438326A (en) | Hypo eutectoid Post-Welding Heattreatment of Rail method | |
| CN112226609A (en) | Construction method for heat treatment of post-welded joints of dissimilar steel rails | |
| CN112063826B (en) | 1300 MPa-level low-alloy heat treatment steel rail postweld heat treatment method | |
| CN113621881B (en) | Method for improving low-temperature toughness of medium-carbon steel rail welded joint | |
| CN110042218A (en) | Construction method for the heat treatment of bainite rail postwelding connector | |
| CN110438327A (en) | Hypo eutectoid steel rail weld joint heat treatment method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220624 Address after: 610306 Chengdu City, Chengdu, Sichuan, China (Sichuan) free trade test zone, Chengdu City, Qingbaijiang District, xiangdao Boulevard, Chengxiang Town, No. 1509 (room 13, A District, railway port mansion), room 1319 Patentee after: Chengdu advanced metal material industry technology Research Institute Co.,Ltd. Patentee after: Panzhihua Iron and Steel Group Panzhihua iron and Steel Research Institute Co., Ltd. Address before: 617000 Taoyuan street, East District, Panzhihua, Sichuan Province, No. 90 Patentee before: PANGANG GROUP PANZHIHUA IRON & STEEL RESEARCH INSTITUTE Co.,Ltd. |