CN106166639A - A kind of welding method of low-alloy pipe line steel - Google Patents
A kind of welding method of low-alloy pipe line steel Download PDFInfo
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- CN106166639A CN106166639A CN201610514131.0A CN201610514131A CN106166639A CN 106166639 A CN106166639 A CN 106166639A CN 201610514131 A CN201610514131 A CN 201610514131A CN 106166639 A CN106166639 A CN 106166639A
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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
- B23K9/00—Arc welding or cutting
- B23K9/16—Arc welding or cutting making use of shielding gas
- B23K9/167—Arc welding or cutting making use of shielding gas and of a non-consumable electrode
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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
- B23K2101/00—Articles made by soldering, welding or cutting
- B23K2101/04—Tubular or hollow articles
- B23K2101/10—Pipe-lines
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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
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/02—Iron or ferrous alloys
- B23K2103/04—Steel or steel alloys
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Abstract
The invention discloses the welding method of a kind of low-alloy pipe line steel, relate to Steel material welding field, solve this Steel material easily by the problem of acid medium corrosion cracking.The method comprise the steps that employing argon tungsten-arc welding carries out root bead, in the welding direction of described root bead to, use SMAW be filled with capping, in the welding direction of described filling capping to, use the mode of described root bead and described filling capping workpiece is welded and forms welding point.The method of the present invention by welding material and welding procedure rationally select make weld metal obtain preferable mechanical property and corrosion resistance, thus avoid low-alloy pipe line steel as far as possible and be easily corroded the phenomenon of cracking, preferably meet actual demands of engineering.
Description
Technical field
The present invention relates to Steel material welding field, particularly relate to the welding method of a kind of low-alloy pipe line steel.
Background technology
Along with oil, the continuous growth of Natural Gas Demand, oil, the mining conditions of gas well deteriorate increasingly, complexity, some H2S
The harsh oil gas field of corrosive environment that content is high is developed in succession, promotes the petroleum gas adapted under this kind of acid service condition
Conveying steel pipe is developed and is produced, and low-alloy pipe line steel is because possessing good welding performance, mechanical property and corrosion resistance
Can and developed widely and used.Low-alloy steel L245NCS has been widely used in high containing H at present2S gas field gathering line,
L245NCS pipe line steel is the trade mark of the steel used under acid service condition meeting GB/T9711.3-2005 standard, with surrender
Intensity is foundation, and this grade of steel is similar to the trade mark B in pipe line steel (API SPEC 5L).L245NCS pipe line steel chemical composition except C,
Outside the essential elements such as Si, Mn, also added the trace element such as Cu, Ni, Cr, Mo, Ti, V so that it is possess good hot and cold processing
Performance, welding performance, mechanical property and corrosion resisting property.
The phenomenon that low-alloy pipe line steel is generally corroded by acid medium in oil and gas transmission, is mainly manifested in sulfuration
Thing stress corrosion cracking and hydrogen induced cracking (HIC), they are destructive in pipe line steel corrosion type and the great etch state of hazardness,
This corrosion failure time of origin is typically the shortest, causes tubing and casing to break crisp accident.Therefore, the corrosion of natural gas transmission pipeline is solved
Problem, is all of designer and ultimate challenge that builder faces, is again the difficult problem that must pull against simultaneously.
In order to solve above-mentioned pipeline corrosion problem, traditional handicraft mainly by the research work of stress corrosion cracking around mother metal
Carry out, and welding procedure is immature.Therefore, existing research one of being badly in need of can effectively prevent low-alloy pipe line steel rotten by acid medium
The welding method of erosion cracking.
Summary of the invention
In view of this, embodiments providing the welding method of a kind of low-alloy pipe line steel, main purpose is to reduce
Low-alloy pipe line steel is by the phenomenon of acid medium corrosion cracking.
For reaching above-mentioned purpose, invention broadly provides following technical scheme:
On the one hand, the invention provides the welding method of a kind of low-alloy pipe line steel, comprise the following steps: use tungsten electrode argon
Arc-welding carries out root bead, in the welding direction of described root bead to, use SMAW be filled with capping, described filling capping
In welding direction to, use the mode of described root bead and described filling capping workpiece is welded and forms welding point.
As preferably, the steel trade mark of described low-alloy pipe line steel is L245NCS.
As preferably, the argon arc welding wire model of described root bead is ER70S-3 φ 2.4mm, the welding rod type of described filling capping
Number it is low hydrogen type E4315 φ 3.2mm.
As preferably, described welding method includes carrying out described welding point heat treatment, and the step of described heat treatment is:
Utilize crawler type electric heater that welding point is heated to 300 DEG C, then rise to 610 with the programming rate less than or equal to 120 DEG C/h
DEG C-630 DEG C and be incubated 50min-70min, insulation is down to 300 DEG C with the cooling rate less than or equal to 100 DEG C/h after terminating, and 300
Power-off natural cooling below DEG C.
As preferably, joint bevel during described welding is double V-groove, the lower half opening angle of described groove is 55 °-
65 °, the first half opening angle of described groove is 25 °-35 °, a length of 0.5mm-1.5mm of root face of described groove, described slope
The alignment clearance of mouth is 2.0mm-3.0mm.
As preferably, the root bead layer thickness of described root bead is more than or equal to 2.5mm-3.5mm, and the weld seam number of plies is 4-6 layer, reinforcement
Less than or equal to 2.0mm-2.2mm, the every side of cap weld width ratio groove of described filling capping increases 1.0mm-2.0mm, misalignment
Less than or equal to 1mm-1.2mm.
As preferably, the equipment of described welding is pipeline welder.
Compared with prior art, the invention has the beneficial effects as follows:
The present invention is directed to low-alloy pipe line steel easily corroded by acid medium in oil and gas transmission and produce corrosion and open
Split the technical problem with hydrogen induced cracking (HIC), by rationally selecting welding material in low-alloy pipe line steel welding process, using rationally
Welding procedure and reasonably post weld heat treatment technique can make welding point metal obtain preferable mechanical property and corrosion resistance
Can, thus meet actual demands of engineering.
Detailed description of the invention
By further illustrating the technological means and effect that the present invention taked by reaching predetermined goal of the invention, below and
Preferred embodiment, to the foundation detailed description of the invention of the present patent application, technical scheme, feature and effect thereof, after describing in detail such as.
Special characteristic, structure or feature in multiple embodiments in the description below can be combined by any suitable form.
Embodiment 1
Select welding material: use argon tungsten-arc welding to carry out root bead, to, the argon arc welding wire of root bead in the welding direction of root bead
Model is the ER70S-3 φ 2.4mm that Bole company produces；Use SMAW to be filled with capping, fill the welding of capping
On direction to, fill capping welding rod model be Atlantic Ocean company produce low hydrogen type E5015 φ 3.2mm；Use root bead and filling
The workpiece of the low-alloy pipe line steel material that the steel trade mark is L245NCS is welded and forms welding point by the mode of capping；Weldering
The equipment of connecing is the PipePro 450 RFC pipeline welder that Miller company of the U.S. produces；
Design welding condition: joint bevel during welding is designed as double V-groove, and the lower half opening angle of groove is
55 °, the first half opening angle of groove is 25 °, a length of 0.5mm of root face of groove, and the alignment clearance of groove is 2.0mm；Root
The root bead layer thickness of weldering is more than or equal to 2.5mm, and the weld seam number of plies is 4, and reinforcement is 2.0mm, fills the cap weld width ratio of capping
The every side of groove increases 1.0mm, and misalignment is 1mm；Welding condition is shown in Table 1；
Post weld heat treatment: utilize crawler type electric heater that welding point is heated to 300 DEG C, then the intensification with 100 DEG C/h
Speed rises to 610 DEG C and is incubated 50min, and insulation is down to 300 DEG C with the cooling rate of 85 DEG C/h after terminating, less than 300 DEG C power-off
Naturally cool to room temperature.
Embodiment 2
Select welding material: use argon tungsten-arc welding to carry out root bead, to, the argon arc welding wire of root bead in the welding direction of root bead
Model is the ER70S-3 φ 2.4mm that Bole company produces；Use SMAW to be filled with capping, fill the welding of capping
On direction to, fill capping welding rod model be Bole company produce low hydrogen type E4315 φ 3.2mm；Use root bead and filling
The workpiece of the low-alloy pipe line steel material that the steel trade mark is L245NCS is welded and forms welding point by the mode of capping；Weldering
The equipment of connecing is the PipePro 450 RFC pipeline welder that Miller company of the U.S. produces；
Design welding condition: joint bevel during welding is designed as double V-groove, and the lower half opening angle of groove is
60 °, the first half opening angle of groove is 30 °, a length of 0.5mm of root face of groove, and the alignment clearance of groove is 2.0mm；Root
The root bead layer thickness of weldering is more than or equal to 3.0mm, and the weld seam number of plies is 4, and reinforcement is 2.0mm, fills the cap weld width ratio of capping
The every side of groove increases 1.0mm, and misalignment is 1mm；Other welding conditions are shown in Table 1；
Post weld heat treatment: utilize crawler type electric heater that welding point is heated to 300 DEG C, then the intensification with 100 DEG C/h
Speed rises to 620 DEG C and is incubated 1 hour, and insulation is down to 300 DEG C with the cooling rate of 90 DEG C/h after terminating, less than 300 DEG C power-off
Naturally cool to room temperature.
Embodiment 3
Select welding material: use argon tungsten-arc welding to carry out root bead, to, the argon arc welding wire of root bead in the welding direction of root bead
Model is that Atlantic Ocean company produces ER50-6 φ 2.0mm；Use SMAW to be filled with capping, fill the welding side of capping
Upwards to, fill capping welding rod model be Atlantic Ocean company produce low hydrogen type E5015 φ 3.2mm；Use root bead and filling
The workpiece of the low-alloy pipe line steel material that the steel trade mark is L245NCS is welded and forms welding point by the mode of capping；Weldering
The equipment of connecing is the PipePro 450 RFC pipeline welder that Miller company of the U.S. produces；
Design welding condition: joint bevel during welding is designed as double V-groove, and the lower half opening angle of groove is
65 °, the first half opening angle of groove is 35 °, a length of 1mm of root face of groove, and the alignment clearance of groove is 2.5mm；Root bead
Root bead layer thickness more than or equal to 4.0mm, the weld seam number of plies is 5, and reinforcement is 1.7mm, fills the cap weld width ratio slope of capping
The every side of mouth increases 1.5mm, and misalignment is 0.8mm；Other welding conditions are shown in Table 1；
Post weld heat treatment: utilize crawler type electric heater that welding point is heated to 300 DEG C, then the intensification with 120 DEG C/h
Speed rises to 625 DEG C and is incubated 65 minutes, and insulation is down to 300 DEG C with the cooling rate of 100 DEG C/h after terminating, and less than 300 DEG C break
Electricity naturally cools to room temperature.
Embodiment 4
Select welding material: use argon tungsten-arc welding to carry out root bead, to, the argon arc welding wire of root bead in the welding direction of root bead
Model is the ER50-6 φ 2.0mm that Atlantic Ocean company produces；Use SMAW to be filled with capping, fill the welding of capping
On direction to, fill capping welding rod model be Atlantic Ocean company produce low hydrogen type E4315 φ 3.2mm；Use root bead and fill out
The workpiece of the low-alloy pipe line steel material that the steel trade mark is L245NCS is welded and forms welding point by the mode filling capping；
Welding equipment is the PipePro 450 RFC pipeline welder that Miller company of the U.S. produces；
Design welding condition: joint bevel during welding is designed as double V-groove, and the lower half opening angle of groove is
65 °, the first half opening angle of groove is 35 °, a length of 1.5mm of root face of groove, and the alignment clearance of groove is 3.0mm；Root
The root bead layer thickness of weldering is more than or equal to 5.0mm, and the weld seam number of plies is 6, and reinforcement is 2.0mm, fills the cap weld width ratio of capping
The every side of groove increases 2.0mm, and misalignment is 1mm；Other welding conditions are shown in Table 1；
Post weld heat treatment: utilize crawler type electric heater that welding point is heated to 300 DEG C, then the intensification with 100 DEG C/h
Speed rises to 630 DEG C and is incubated 70min, and insulation is down to 300 DEG C with the cooling rate of 90 DEG C/h after terminating, less than 300 DEG C power-off
Naturally cool to room temperature.
Table 1. welding condition
Each embodiment is a kind of technical scheme, and each scheme the most parallel welding ten group welding piece is using as follow-up performance
Detection sample；
All weldments after welding embodiment 1-4 carry out performance test: after post weld heat treatment, treat that weldment cools down, foundation
SY/T0452-2002, SY/T4109-2005 standard-required Welded Joints carries out appearance test, x-ray inspection inspection, implements
Four weldments of example 1-4 are the most qualified.
The mechanical property of Welded Joints is tested:
(1) stretching experiment: using model is the electronic universal tester of WDW-100D, according to GB228-2002 " metal material
Material tensile testing at ambient temperature " standard and SY/T0452-2002 " Weld Procedure Qualification of Oil & Gas Metal Pipeline " standard enter
Row tension test result evaluation；Tensile property testing result is shown in Table 2；
Table 2 stretch test result
Note: in table, in specimen coding, first digit represents testing program sequence number, second digit represents test sequence number, the
Three digitized representation test specimen sequence numbers.
Table 2 is the stretch test result of eight weldments that four embodiment welding obtain.It can be seen that the ring of four kinds of schemes
The tensile strength values of weld seam is more or less the same, and all ruptures in mother metal position.Four kinds of schemes are showed no substantially surrender.Because during welding
All using high coupling or wait coupling, welding quality is preferably simultaneously, so fracture position is at mother metal.And scheme 2, the weld seam of scheme 4
Tensile strength is slightly below scheme 1, scheme 3, relevant with the tensile strength difference filling out capping welding rod E5015 with E4315.According to SY/
T0452-2002 " Weld Procedure Qualification of Oil & Gas Metal Pipeline " standard tensile test result evaluation requires: Mei Geshi
The tensile strength of sample is not lower than the lower limit of mother metal tensile strength standard value, and (" industrial gas oil is defeated for GB/T9711.1-1997
Steel pipe is sent to deliver goods technical conditions Part I: A level steel pipe " regulation L245NCS minimum tensile strength is 415MPa), it is known that four
Scheme all reaches the scope of standard-required.
(2) bend test: bend test is carried out according to GBT232-1999 " bend test of metal materials method " regulation；Curved
Bent specimen size is shown in Table 3；
Table 3 bend specimen size
Require according to SY/T0452-2002 standard bend test result evaluation: the angle of bend of bend test is
180 °, when angle of bend should bear load with sample, measurement is as the criterion；When sample bending shaft of going for a stroll is to after predetermined angular, its Extrude Face
Any direction on must not have the crackle that length is more than 3mm, the cracking that sample edges and corners occur can be disregarded, but due to slag inclusion or its
On the corner angle that his internal flaw causes, crack length should count.During bend test, the Weld pipe mill on sample should be directed at bending axis
Line, Seam and heat effected zone should all at sample by curved scope；Bend test the results are shown in Table 4；
Table 4 bend test test result
As known from Table 4, scheme 1, scheme 2 dough-making powder be curved, root bend test is showed no defect.Scheme 3, scheme 4 face-bend test are not
See defect, but root bend test two test specimen occurs the crackle of long 2～4mm respectively.As can be seen here, scheme 3, the bending resistance of scheme 4 weld seam
Poor performance, because scheme 3, scheme 4 root bead use ER50-6 welding wire, this welding wire poor toughness, percentage elongation is relatively low, therefore anti-bending strength
Less better.
(3) impact test: impact specimen uses machining, its form and test method according to GB/T229-2007 " gold
Belong to material Charpy pendulum impact test method " regulation carry out；Low-temperature impact test, specimen size 7.5 × 10 × 55mm, sample
Type V-type, test temperature-5 DEG C, result of the test is shown in Table 5；
Table 5 impact test test result
From 5 four scheme weld metal zones of table, heat affected area impact value it can be seen that the impact value of scheme 2 weld metal zone is higher than
The impact value of other three scheme weld metal zones, can be summarized as: scheme 2 ＞ scheme 1 ＞ scheme 4 ＞ scheme 3, four scheme heat affectings
District's impact value is more or less the same.These hardening constituent, a large amount of crystal defect and structural heterogenities etc. formed when being due to welding reduce
Weld dimensions metal impact toughness.Improve the mobility of atom by heat treatment heating process, can eliminate
Segmental defect；Next to that at heat treatment cooling stage, control 620 DEG C to 320 DEG C interval cooling rates of maximum temperature, ferrite
The surplus carbon of middle dissolving separates out with compound form, weakens the pinning effect to dislocation, and post weld heat treatment simultaneously also has uniform group
The effect knitted, causes the impact flexibility of steel to be improved.From Impulse Test Result it will be seen that the impact of four scheme weld metal zones
Value is below heat affected area.Ballistic work is the highest, and impact flexibility is the best, and material is just difficult to brittle fracture occur.Heat affected area
Toughness be higher than weld seam, then fracture position easily occurs in weld metal zone, therefore welding point be L245NCS pipe line steel produce in thin
Weak link.
(4) the disconnected test of cutting hammer: the regulation of the disconnected test basis standard SY/T 0452-2002 of cutting hammer is carried out；Exist with hacksaw
The center kerf of sample two side weld section, the degree of depth of each groove about 3.2mm.The sample prepared by the method, it is possible to break
On mother metal the most in welded joints.When current single test shows to rupture at mother metal, for ensureing that fracture breaks at weld seam
On, then can cutting on face of weld reinforcement, but the degree of depth is counted from surface and be must not exceed 1.6mm.The disconnected sample of cutting hammer can be
Break on stretching-machine；Or support two ends, in the middle part of strike, hammer is disconnected；Or support one end strike other end.The exposure face width of welding seam breaking
Degree must not drop below 19mm；Welding point is carved the disconnected result of the test of hammer and is shown in Table 6；
The disconnected test of table 6 cutting hammer is freed
It can be seen that two cutting hammers of scheme 1, scheme 2 are disconnected tests test specimens the most not from the disconnected result of the test table 6 of cutting hammer
See that section defect, scheme 3, one of them test specimen of scheme 4 occur diameter 1mm and the pore of diameter 0.8mm respectively.Four schemes
The cutting disconnected result of the test of hammer be satisfied by the disconnected test requirements document of SY/T 0452-2002 standard cutting hammer (plane of disruption of each test specimen should
Complete penetration and fusion；Pore greatest length is not more than 1.6mm；Leachy cumulative area should be not more than area of fracture
2%).
(5) hardness test: hardness test establishing criteria GB/T4340-1999 " Vickers Hardness Test " regulation is carried out；
3 position samples of girth joint, corrode with suitable caustic butt welded seam cross section after sample polishing, distinguish weld seam, hot shadow
Ringing district and the position of mother metal, test uses 10kg load test power；Result of the test is shown in Table 7；
Table 7 hardness test result (HV)
As can be seen from Table 7, four kinds of schemes are after post weld heat treatment, and weld metal zone hardness number is followed successively by: scheme 3 ＞ scheme
1 ＞ scheme 4 ＞ scheme 2, heat affected area hardness number scheme 3 is higher than scheme 1, scheme 2, scheme 4, the weld metal zone of four kinds of schemes, heat
The hardness number of the zone of influence is all higher than mother metal；But hardness (HV) value the most very much not surpasses after the welded heat treatment of girth joint of four kinds of schemes
Cross 143HV, specify that the hardness number of any testing site of hardness test is not more than wanting of 248HV far below SY/T 0452-2002 standard
Ask.
By above-described embodiment many group welding pieces of obtaining of welding being carried out the test of five kinds of mechanical properties: above-mentioned four kinds
Every mechanical property test of scheme all can meet SY/T 0452-2002 standard-required.Can from four kinds of scheme tension tests
Going out, or high-strength coupling strong because of employing etc. and relatively high welding quality, the welding point of four kinds of schemes is respectively provided with higher-strength.In conjunction with four
Impact test and the hardness test result of the scheme of kind show, the welding point of four kinds of schemes is respectively provided with good toughness.
Bend test and the disconnected result of the test of cutting hammer show, scheme 1, scheme 2 have preferable anti-bending strength, weld seam section
Quality is good, and scheme 3, scheme 4 anti-bending strength are poor, and weld seam section has certain defect, but is not enough to affect weld joint mechanical
Performance, it is possible to meet engineer applied requirement.From four kinds of scheme welding point every mechanical property test results in general, technique
Scheme 2 is slightly better than other three process programs.
Welded Joints microstructure is analyzed:
Prepare sample: welding point Analysis on Microstructure is according to GB/T13298-1991 " the metal microstructure method of inspection "
Regulation is carried out.Intercept sample from 3 positions of each weldment girth joint respectively, sample one section is carried out machine sanding and polishing, as
Inspection surface, then after eroding it with 4% nitric acid ethanol, using model is that XJG-05 metallurgical microscope carries out microscopic structure and divides
Analysis and the mensuration of grain size.
Analysis by the microstructure to the welding point obtained by above-mentioned four kinds of schemes:
The welding point microscopic metallographic structure of (1) 4 kind of scheme: cap weld has the ferrite and pearlite of thick bulk
+ granular bainite, in root bead district and fill area all with isometry or the granular ferrite+pearlite of better performances.Each at weld seam
Position, due to different by heat effect in welding process, its tissue is different: when root bead and filling weldering, due to the heat input of rear layer
Having " tempering " to act on to preceding layer so that its even tissue, crystal grain is tiny, is the ferrite+pearlite of isometry or bulk.Lid
During the weldering of face, lacking " annealing " effect of rear layer, wherein scheme 1, scheme 3 occur.
(2) seam organization substantially ratio process program 1,3 fine microstructures of scheme 2,4, particularly at cap weld, such as scheme
1 and scheme 3 all occur in that thick bulk is distributed eutectoid ferrite along original austenite crystal prevention.
(3) organization decided performance.The stress corrosion inclination of Hi-Stren steel is substantially passed by the sequence of metallographic structure
Increase, i.e. globular pearlite → 500 DEG C annealing martensite → lamellar ferrite and pearlite → martensite.Due in welding process
In, have selected suitable thermal weld stress, and strictly control interlayer temperature, root bead layer and packed layer all with better performances etc.
Axle or granular ferrite+pearlite, although having thick ferrite+pearlite grain at cap weld, but Resistance of Weld Metal is evaluated
Main consideration root bead layer metal, the anti-SSCC performance impact of the thick ferrite Welded Joints of capping layer is little.
Welded Joints chemical composition is analyzed:
Prepare sample: welding point chemical composition analysis is according to GB/T14203-1993 " iron and steel and alloy photoemission light
Zymography general rule " carry out with GB/T4336-1984 " the photoemission spectrum analysis of carbon steel and middle-low alloy steel " regulation.Examination
Testing instrument is model BHWLD-4D direct-reading capacitance meter.From weldment deposited metal position cut-off footpath 30mm, highly 20mm column
Sample；Using the bulk sample that processes as a click, luminous with light source activation, and this light beam is introduced spectrometer, pass through
Dispersion original paper resolves into spectrum.The intensity of the internal standard line selected and analytical line is carried out photoelectric measurement, according to the standard sample system of using
The working curve made, obtains the content of analytical element in sample；Welding point chemical composition analysis the results are shown in Table 8；
Table 8 welding point chemical composition analysis (%)
Chemical composition analysis by the welding point obtained by above-mentioned four kinds of schemes: scheme 3 welding point C unit
Cellulose content is slightly higher compared with scheme 1, scheme 4, and scheme 2 welding point C element content is lower slightly, and C element content affects welding point and quenches
Rigid, the toughness of C element content height Welded Joints, plasticity etc. adversely affect；Scheme 3 welding point Mn constituent content is relatively
Height, will be to its anti-H2S corrosive power has certain impact；The alloying element contents such as scheme 1,2 welding point Cr, Ni, Mo are higher, will
Improve the degree of grain refinement of welding point, to obtain good comprehensive mechanical property.
Four kinds of scheme welding point microscopic metallographic structures: when root bead and filling weldering, owing to the heat input of rear layer is to previous
Layer has " tempering " to act on so that its even tissue, crystal grain is tiny, for isometry or granular ferrite+pearlite.During cosmetic welding, lack
" annealing " effect of layer after few, its tissue coarse grains, there is the ferrite+pearly-lustre of distribution in dendritic crystalline in scheme 2, scheme 4
Body, there is pro-eutectoid ferrite in scheme 1, scheme 3, is distributed along original austenite crystal prevention, and intracrystalline is granular bainite+pearlite+pin
Columnar ferrite.Scheme 2, scheme 4 seam organization substantially than scheme 1,3 fine microstructures.
Four kinds of scheme welding point chemical composition analysis: alloying element content scheme 1, the schemes such as welding point Cr, Ni, Mo
2 are higher than scheme 3, scheme 4；C element content is followed successively by scheme 2 ＜ scheme 4 ＜ scheme 1 ＜ scheme 3；Scheme 3 welding point Mn unit
Cellulose content is higher, will have certain impact to its anti-H2S corrosive power.
SSCC full name sulfide-stress cracking (Sulfide Stress Corrosion Cracking) refers to metal
Material in bearing certain tension and sour corrosion media environment, the brittle fracture of generation[56].It is stress and sulfur-bearing corruption
Losing the corrosion behavior under environment acts on jointly, Neither of the two can be dispensed.Individually stress effect or individually sour corrosion dielectric ring
Border effect will not result in metal material and such destruction occur.The test of Welded Joints anti-SSCC performance: SSCC test depends on
According to GB/T15970.2 " the corrosion stress corrosion testing part 2 of metal and alloy: the preparation of camber beam sample and application " idt
ISO7539-2 and NACETM0177-2005 " metal is the test of environment resistant split test room in hydrogen-sulfide environmental " regulation is carried out.Examination
The condition of testing is shown in Table 9；
Table 9 four-point bending test condition
According to NACE TM0177-2005 standard, testing liquid specifies that solution A is (containing 5.0%NaC1+0.5%CH3COOH+
H2S (saturated) (pH:4.5) deoxygenates distilled water solution), proof stress is at least loaded into selected steel pipe L245NCS standard and specifies
The 85% of little yield strength (σ s=245MPa), the test period is 720 hours, root bead face tension stress.Sample should comprise weld seam,
Fusion area and mother metal and weld seam should be positioned at sample center, size of sample 115 × 15 × 5mm, and sample quantities should be no less than 3
Individual.Test standard specifies, if corrosion sample is at thickness direction crackle≤0.1mm, it is determined that it is rotten that sample has resisting sulfide stress
The ability of erosion cracking.According to the prefabricated test specimen of GB/T15970.2 standard, carrying out sulfide according to NACE TM0177-2005 standard should
Power corrosion cracking (SSCC) is tested, and result of the test is shown in Table 10；
Table 10 sulfide-stress cracking result of the test
As can be seen from Table 10, scheme 1, scheme 2 test specimen SSCC test has no crackle, and scheme 3, scheme 4 local goes out
Existing 0.5～1.0 crackles.
According to SYT0452-2002 " Weld Procedure Qualification of Oil & Gas Metal Pipeline " standard, to L245NCS pipe line steel
Carry out welding procedure experimentation.Experiment is strict controls welding quality and the execution of welding condition, to four kinds of test sides
Case welding point carried out Mechanics Performance Testing, microstructure observation, chemical composition analysis, the test of welding residual stress and
Its anti-SSCC performance test, is concluded that
(1) four kind of tension test of experimental program, bend test, impact test, cutting hammer break and test and hardness test examination
Test result and all can meet SY/T 0452-2002 standard-required.
(2) four kinds of experimental program welding point root beads and filling weldering crystal grain are tiny, even tissue, for isometry or block ferrum element
Body+pearlite.Cosmetic welding tissue coarse grains, there is the ferrite+pearlite of distribution, scheme in dendritic crystalline in scheme 2, scheme 4
1, scheme 3 pro-eutectoid ferrite is distributed along original austenite crystal prevention, and intracrystalline is granular bainite+pearlite+acicular ferrite.Scheme
2, the seam organization of scheme 4 is substantially than scheme 1,3 fine microstructures.
(3) testing the post weld heat treatment Rational Parameters used, four kinds of scheme welding residual stresses are after post weld heat treatment
All having the reduction of about 70%, its residual-stress value all disclosure satisfy that engineer applied requirement.
(4) being contrasted by experimental result, testing program 2 is better than other three testing programs, can be at high sour gas well collection
Defeated pipeline welding is organized and implemented.
Therefore in pipe line steel welding process, rationally select welding material, use reasonable welding procedure and post weld heat treatment
Technique can make weld metal obtain preferable mechanical property and corrosion resistance, thus meets actual demands of engineering.
The detailed description of the invention being only the present invention disclosed above, but protection scope of the present invention is not limited thereto, and appoints
What those familiar with the art, in the technical scope that the invention discloses, can readily occur in change or replace, answering
Contain within protection scope of the present invention.Therefore, protection scope of the present invention should be with above-mentioned scope of the claims
Accurate.
Claims (7)
1. the welding method of a low-alloy pipe line steel, it is characterised in that described method includes: use argon tungsten-arc welding to carry out root
Weldering, in the welding direction of described root bead to, use SMAW be filled with capping, in the welding direction of described filling capping
To, use the mode of described root bead and described filling capping workpiece is welded and forms welding point.
The welding method of a kind of low-alloy pipe line steel the most according to claim 1, it is characterised in that described low-alloy pipeline
The steel trade mark of steel is L245NCS.
The welding method of a kind of low-alloy pipe line steel the most according to claim 1, it is characterised in that the argon arc of described root bead
Welding wire model is ER70S-3 φ 2.4mm, and the welding rod model of described filling capping is low hydrogen type E4315 φ 3.2mm.
The welding method of a kind of low-alloy pipe line steel the most according to claim 1, it is characterised in that described welding method bag
Including and described welding point carries out heat treatment, the step of described heat treatment is: utilize crawler type electric heater to be added by welding point
Heat is to 300 DEG C, then rises to 610 DEG C-630 DEG C with the programming rate less than or equal to 120 DEG C/h and be incubated 50min-70min, insulation
It is down to 300 DEG C with the cooling rate less than or equal to 100 DEG C/h, less than 300 DEG C power-off natural coolings after end.
The welding method of a kind of low-alloy pipe line steel the most according to claim 1, it is characterised in that connecing during described welding
Head groove is double V-groove, and the lower half opening angle of described groove is 55 °-65 °, and the first half opening angle of described groove is
25 °-35 °, a length of 0.5mm-1.5mm of root face of described groove, the alignment clearance of described groove is 2.0mm-3.0mm.
The welding method of a kind of low-alloy pipe line steel the most according to claim 5, it is characterised in that the root bead of described root bead
Layer thickness is more than or equal to 2.5mm-3.5mm, and the weld seam number of plies is 4-6 layer, and reinforcement is less than or equal to 2.0mm-2.2mm, described filling cap
The every side of cap weld width ratio groove in face increases 1.0mm-2.0mm, and misalignment is less than or equal to 1mm-1.2mm.
The welding method of a kind of low-alloy pipe line steel the most according to claim 1, it is characterised in that the equipment of described welding
For pipeline welder.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106363274A (en) * | 2016-12-12 | 2017-02-01 | 四川石油天然气建设工程有限责任公司 | All-position root-welding method for carbon steel and low alloy steel pipeline |
| CN108127216A (en) * | 2017-12-18 | 2018-06-08 | 唐山师范学院 | A kind of low-alloy bainite steel manual argon arc welding connects technique |
| CN111272796A (en) * | 2020-03-14 | 2020-06-12 | 广东韶钢松山股份有限公司 | Method for detecting sulfide inclusions in steel |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102848048A (en) * | 2012-09-07 | 2013-01-02 | 龙口中集来福士海洋工程有限公司 | Pipeline welding method |
| CN103286414A (en) * | 2013-04-27 | 2013-09-11 | 中国石油天然气集团公司 | Welding method of oil gas transmission antisulphour steel pipelines |
| CN104014909A (en) * | 2014-06-24 | 2014-09-03 | 中国华冶科工集团有限公司 | Pipeline welding method |
| CN104227180A (en) * | 2014-09-23 | 2014-12-24 | 重庆舸海机电有限公司 | Welding method for NM400 wear-resistant steel |
| CN104858555A (en) * | 2015-06-10 | 2015-08-26 | 江苏力沛电力工程技术服务有限公司 | Pressure pipeline welding process |
-
2016
- 2016-06-29 CN CN201610514131.0A patent/CN106166639A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102848048A (en) * | 2012-09-07 | 2013-01-02 | 龙口中集来福士海洋工程有限公司 | Pipeline welding method |
| CN103286414A (en) * | 2013-04-27 | 2013-09-11 | 中国石油天然气集团公司 | Welding method of oil gas transmission antisulphour steel pipelines |
| CN104014909A (en) * | 2014-06-24 | 2014-09-03 | 中国华冶科工集团有限公司 | Pipeline welding method |
| CN104227180A (en) * | 2014-09-23 | 2014-12-24 | 重庆舸海机电有限公司 | Welding method for NM400 wear-resistant steel |
| CN104858555A (en) * | 2015-06-10 | 2015-08-26 | 江苏力沛电力工程技术服务有限公司 | Pressure pipeline welding process |
Non-Patent Citations (2)
| Title |
|---|
| 代波等: "L245NCS抗硫管线的焊接工艺", 《科技创新与应用》 * |
| 税正伟: "L245NCS微合金管线钢焊接接头微观组织分析", 《焊接技术》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106363274A (en) * | 2016-12-12 | 2017-02-01 | 四川石油天然气建设工程有限责任公司 | All-position root-welding method for carbon steel and low alloy steel pipeline |
| CN108127216A (en) * | 2017-12-18 | 2018-06-08 | 唐山师范学院 | A kind of low-alloy bainite steel manual argon arc welding connects technique |
| CN111272796A (en) * | 2020-03-14 | 2020-06-12 | 广东韶钢松山股份有限公司 | Method for detecting sulfide inclusions in steel |
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