Summary of the invention
The technical problem to be solved in the present invention provides the manufacture method of the X65 pipeline steel submerged arc straight weld pipe of small-bore, large wall thickness, high strength, high tenacity, high uniform elongation in the usefulness of a kind of seabed.
For solving the problems of the technologies described above, it is C 0.04~0.10%, Mn 1.40~1.75%, Si 0.15~0.35%, S≤0.006%, P≤0.010%, Ni≤0.30%, Mo≤0.30%, Ti≤0.030%, Al 0.015~0.050%, Nb≤0.06%, N≤0.01%, Cu≤0.25%, Cr 0.10~0.30%, B≤0.0005% that the present invention adopts the chemical composition mass percent, surplus is Fe, wherein the X65 controlled rolling steel plate of Ceq≤0.43, Pcm≤0.22 carries out the manufacturing of straight-line joint submerged arc welding tube, and its process for making is:
Mill the limit, groove processing: be the steel plate of 28.6mm, 30.2mm for steel plate thickness, bevel angle is 35 ° up and down, and the width of root face is 9mm, and lower groove depth is respectively 11mm, 12mm; The purpose of finished edge is to guarantee that welding process can complete penetration, forms suitable weld seam pattern, avoids occurring the defectives such as lack of penetration in the high-speed welding process, guarantees the quality of welding point, the realization good quality and high output.
Pre-flanging: require and the caliber size requirement according to steel pipe curvature, utilize pre-flanging machine that edges of boards are bent to satisfactory curvature.
JCO moulding: be that Φ 762mm, wall thickness are the steel pipe of 28.6~30.2mm for the manufacture of caliber, at first utilize the JCO forming machine to carry out Multi-step forming through half of the steel plate behind the pre-flanging, be pressed into " J " shape, carry out again same Multi-step forming with its second half, be pressed into " C " shape, the middle pressing one-time at whole steel plate makes it form " O " shape of opening at last; In the above-mentioned Sheet Metal Forming Technology, adopt the compacting number of times in 15~20 steps, single drafts 21~28mm.
Joint close and prewelding: by adjusting the position of joint close Prewelding machine pressure roller; make the good coupling of the bevel for welding of the steel pipe after the moulding together; guarantee that misalignment, gap size meet the requirements; adopt simultaneously the gas shielded welding mode to weld; form continuous, the stay-in-grade pre-welding line of standard, the steel-pipe welding operating mode is stable when astute and able inside and outside guaranteeing.
Interior weldering: adopt four Lincoln welds to weld at the inboard bevel for welding of steel pipe, first is adopted dc reverse connection, and second to four for exchanging; The steel-pipe welding technological parameter is: first electric current I=1100~1200A, voltage U=32~36V; Second electric current I=900~1000A, voltage U=36~40V; The 3rd electric current I=750~850A, voltage U=38~42V; The 4th electric current I=650~750A, voltage U=40~44V; Distance between weldingwires d=30~35mm, welding speed V=110~150cm/min.
Outside weld: adopt four Lincoln welds to weld at steel pipe outside bevel for welding, first is adopted dc reverse connection, and second to four for exchanging; The steel-pipe welding technological parameter is: first electric current I=1100~1200A, voltage U=32~36V; Second electric current I=900~1000A, voltage U=36~40V; The 3rd electric current I=750~850A, voltage U=38~42V; The 4th electric current I=650~750A, voltage U=40~44V; Distance between weldingwires d=30~35mm, welding speed V=120~150cm/min.
The mass percent of weld seam chemical composition is C 0.04~0.10%, Mn 1.65~2.0%, Si 0.15~0.35%, S≤0.01%, P≤0.015%, Ni 0.05~0.35%, Mo 0.1~0.30%, V≤0.06%, Ti≤0.035%, Al≤0.050%, Nb≤0.06%, N≤0.015%, Cu≤0.30%, Cr≤0.50%, B≤0.0015%, Ceq 0.38~0.46, Pcm≤0.22 in the said welding method, and the microscopic structure of described weld seam is that acicular ferrite is main tissue.
For the first time ultrasonic examination: steel pipe inner and outer welding and heat affected area, weld seam both sides part after the welding are carried out 100% inspection.
X-ray examination for the first time: the steel pipe inner and outer welding after adopting image processing system to welding carries out 100% industrial television inspection, guarantees flaw detection sensitivity.
Machinery expanding: the steel pipe total length is carried out 0.5%~1.2% hole enlargement with the dimensional accuracy of raising steel pipe, and improve the internal stress distribution of steel pipe.
The water pressure test: steel pipe is carried out 100% the smart water pressure test, and test pressure is 95%~100% of the regulation SMYS, checks the strength level of steel pipe and whether has leakage point.
Chamfered edge: the above-mentioned steel pipe that is up to the standards is carried out tube end maching, reach the pipe end slope-mouth dimensional requirement of customer requirement.
For the second time ultrasonic examination: the steel pipe inner and outer welding behind hole enlargement, the hydraulic pressure and heat affected area, weld seam both sides part are carried out 100% inspection, to get rid of hole enlargement, the issuable defective of hydraulic pressure.
X-ray examination for the second time: the steel pipe inner and outer welding behind hole enlargement, the hydraulic pressure carried out 100% industrial television inspection and pipe end film making and check, to get rid of hole enlargement, the issuable defective of hydraulic pressure.
Pipe end magnetic particle inspection and presentation quality inspection: in case of necessity pipe end is carried out magnetic particle inspection, the steel pipe apparent size is measured, presentation quality is checked, qualified steel pipe carries out anticorrosion and coating according to customer requirements on inspection.
Beneficial effect of the present invention is as follows:
(1) by to X65 controlled rolling steel plate alloying component control and microstructures Control, make steel plate have high strength, high tenacity, high uniform elongation and narrower intensity interval.
(2) by in the JCO moulding process, according to steel plate width, thickness, intensity and die size, Accurate Analysis is determined rational punching press number of times and single drafts, the straight-line joint submerged arc welding tube JCO forming process light plate inhomogeneous deformation that has solved X65 grade of steel diameter and be Φ 762mm, wall thickness and be 28.6~30.2mm causes partial operation sclerosis, toughness and the uniform elongation serious problem that descends, and the each several part distortion evenly in the JCO forming process, performance is even to make steel pipe.According to analysis result and field trial, analyze steel plate forming process spring-go amount, rationally determine draught per pass, have good circularity after making steel pipe forming.
(3) in the expanding technology, according to the size behind the steel pipe forming, shape situation, determine best expanding technology, guarantee size behind the pipe expanding, shape and physicochemical property, solved steel pipe when machinery expanding because the problem that work hardening causes strength increase, toughness and uniform elongation to reduce.
(4) in the welding procedure, at first by the preferred weld material, guarantee that weld seam has the intensity of a little higher than mother metal and good toughness.When determining welding parameter; take into full account in four wire bonds effect of each; by each electric current of reasonable setting, voltage, angle, distance between weldingwires and speed of welding, make weld seam obtain suitable depth of penetration and good pattern, be conducive to simultaneously gas and covering slag come-up in the welding process.On this basis, in order to reduce sweating heat to the impact of heat affected area obdurability, each current/voltage is further optimized, taked lower welding wire energy, guarantee the performance of welding heat affected zone.Weld seam is final to be obtained take acicular ferrite as tissue main, that have good obdurability, has solved steel pipe local heating in welding process and has caused obdurability and the serious problem that reduces of percentage elongation.
By the strict technology control of each operation, make the properties of final steel pipe meet straight-line joint submerged arc welding tube is used in the seabed with X65 grade of steel pipeline requirements fully.
The specific embodiment
The present invention is further detailed explanation below in conjunction with specific embodiment.
Embodiment 1
The employing wall thickness is that 28.6mm, chemical composition are that the X65 controlled rolling steel plate of C 0.06%, Mn 1.61%, Si 0.19%, S 0.0012%, P 0.007%, Mo≤0.098%, Ni+Cr+Cu 0.157%, V+Nb+Ti 0.062%, N 0.005%, Ceq 0.36, Pcm 0.15 carries out the manufacturing of straight-line joint submerged arc welding tube, and process for making is as follows:
Mill the limit: steel plate meets 35 ° of upper and lower bevel angles, width of root face 9mm after milling the limit.
Pre-flanging: utilize pre-flanging machine to carry out edges of boards pre-bending, according to the caliber size requirement, make edges of boards have satisfactory curvature.
JCO moulding: adopt the progressively method of compacting, the each feeding 134mm of steel plate, first half of steel plate is pressed into " J " type through 7 times, adopt and carry out in the same way second half compacting, become " C " type, suppress in the centre of steel plate at last, make whole steel plate be pressed into " O " type of opening, opening is less than 120mm.Whole compacting passage is 15 roads, and each drafts is 22~28mm.
Joint close and prewelding: steel pipe is sent into the joint close Prewelding machine by track; by adjusting the position of joint close Prewelding machine 9 row pressure rollers; make the good coupling of the bevel for welding of the steel pipe after the moulding together, adopt the gas shielded welding mode to weld, form continuously, standard, stay-in-grade pre-welding line.
Interior weldering: adopt four Lincoln welds to weld at the inboard bevel for welding of steel pipe, first is adopted dc reverse connection, and second to four for exchanging.Welding condition is: first electric current 1150A, voltage 34V, and second electric current 950A, voltage 38V, the 3rd electric current 800A, voltage 40V, the 4th electric current 700A, voltage 42V, distance between weldingwires is 33mm, speed of welding is 135mm/min.
Outside weld: adopt four Lincoln welds to weld at steel pipe outside bevel for welding, first is adopted dc reverse connection, and second to four for exchanging.Welding condition is: first electric current 1200A, voltage 34V, and second electric current 950A, voltage 38V, the 3rd electric current 800A, voltage 40V, the 4th electric current 700A, voltage 42V, distance between weldingwires is 33mm, speed of welding is 145mm/min.
The mass percent of weld seam chemical composition is C 0.06%, Mn 1.88%, Si 0.30%, S 0.0034%, P 0.011%, Ni 0.094%, Mo 0.177%, V 0.002%, Ti 0.020%, Al 0.017%, Nb 0.024%, N 0.009%, Cu 0.016%, Cr 0.022%, B 0.0007%, Ceq 0.42, Pcm 0.17 in the said welding method, and the microscopic structure of weld seam is that acicular ferrite is main tissue.
Ultrasonic inspection I: steel pipe inner and outer welding and heat affected area, weld seam both sides part after the welding are carried out 100% inspection.
X-ray examination I: the steel pipe inner and outer welding after the welding is carried out 100% industrial television inspection.
Machinery expanding: the steel pipe total length is carried out 0.8% hole enlargement with the dimensional accuracy of raising steel pipe, and improve the internal stress distribution of steel pipe.
The water pressure test: steel pipe is carried out 100% hydrostatic test, test pressure 32.5MPa, the dwell time is greater than 20s.
Chamfered edge: carry out tube end maching, be processed into satisfactory pipe end slope-mouth.
Ultrasonic inspection II: the steel pipe inner and outer welding behind hole enlargement, the hydraulic pressure and heat affected area, weld seam both sides part are carried out 100% inspection, to get rid of hole enlargement, the issuable defective of hydraulic pressure.
X-ray examination II: the steel pipe inner and outer welding behind hole enlargement, the hydraulic pressure is carried out 100% industrial television inspection and pipe end film making inspection, to get rid of hole enlargement, the issuable defective of hydraulic pressure.
Pipe end magnetic particle inspection: in case of necessity pipe end is carried out magnetic particle inspection.
Anticorrosion and coating: qualified steel pipe carries out anticorrosion and coating according to customer requirements.
What table 1, table 2, table 3 and table 4 provided is the physicochemical property testing result of the steel pipe material object of present embodiment, by table as seen, utilizes the X65 pipeline steel submerged arc straight weld pipe of technology manufacturing of the present invention to reach specification requirement.
Table 1 steel pipe Erichsen test result
R
t0.5 MPa
|
R
m ?MPa
|
R
t0.5/Rm
|
A
50 %
|
Uniform elongation % |
Remarks |
530 |
630 |
0.84 |
56.0 |
/ |
Horizontal sample |
510 |
610 |
0.83 |
58.0 |
7.5% |
Longitudinal test piece |
/ |
655 |
/ |
/ |
/ |
Welding point |
Stress strain curve is the dome type.
Table 2 Charpy-type test result
Table 3 DWTT section of shear rate (0 ℃)
1 |
2 |
On average |
100 |
100 |
100 |
Table 4 hardness test result (HV10)
Embodiment 2
The employing wall thickness is that 30.2mm, chemical composition are that the X65 controlled rolling steel plate of C 0.07%, Mn 1.58%, Si 0.31%, S 0.001%, P 0.007%, Mo≤0.014%, Ni+Cr+Cu 0.216%, V+Nb+Ti 0.046%, N 0.004%, Ceq 0.40, Pcm 0.18 carries out the manufacturing of straight-line joint submerged arc welding tube, and process for making is as follows:
Mill the limit: steel plate meets 35 ° of upper and lower bevel angles, width of root face 9.0mm after milling the limit.
Pre-flanging: utilize pre-flanging machine to carry out edges of boards pre-bending, according to the caliber size requirement, make edges of boards have satisfactory curvature.
JCO moulding: adopt the progressively method of compacting, the each feeding 134mm of steel plate, first half of steel plate is pressed into " J " type through 7 times, adopt and carry out in the same way second half compacting, become " C " type, suppress in the centre of steel plate at last, make whole steel plate be pressed into " O " type of opening, opening is less than 120mm.Whole compacting passage is 15 roads, and each drafts is 21~27mm.
Joint close and prewelding: steel pipe is sent into Prewelding machine by track; by adjusting the position of joint close Prewelding machine 9 row pressure rollers; make the good coupling of the bevel for welding of the steel pipe after the moulding together, adopt the gas shielded welding mode to weld, form continuously, the stay-in-grade pre-welding line of standard.
Interior weldering: adopt four Lincoln welds to weld at the inboard bevel for welding of steel pipe, first is adopted dc reverse connection, and second to four for exchanging.Welding procedure is: first electric current 1150A, voltage 34V; Second electric current 950A, voltage 38V; The 3rd electric current 800A, voltage 40V; The 4th electric current 700A, voltage 42V; Distance between weldingwires is 33mm; Speed of welding is 125mm/min.
Outside weld: adopt four Lincoln welds to weld at steel pipe outside bevel for welding, first is adopted dc reverse connection, and second to four for exchanging.Welding procedure is: first electric current 1200A, voltage 34V; Second electric current 950A, voltage 38V; The 3rd electric current 800A, voltage 40V; The 4th electric current 700A, voltage 42V; Distance between weldingwires is 32mm; Speed of welding is 135mm/min.
The mass percent of weld seam chemical composition is C 0.06%, Mn 1.92%, Si 0.31%, S 0.003%, P 0.011%, Ni 0.103%, Mo 0.188%, V 0.003%, Ti 0.025%, Al 0.022%, Nb 0.031%, N 0.009%, Cu 0.021%, Cr 0.029%, B 0.0008%, Ceq 0.43, Pcm 0.18 in the said welding method, and the microscopic structure of weld seam is that acicular ferrite is main tissue.
Ultrasonic inspection I: steel pipe inner and outer welding and heat affected area, weld seam both sides part after the welding are carried out 100% inspection.
X-ray examination I: the steel pipe inner and outer welding after the welding is carried out 100% industrial television inspection.
Machinery expanding: the steel pipe total length is carried out 0.8% hole enlargement with the dimensional accuracy of raising steel pipe, and improve the internal stress distribution of steel pipe.
The water pressure test: steel pipe is carried out 100% hydrostatic test, test pressure 34.4MPa, the dwell time is greater than 15s.
Chamfered edge: carry out tube end maching, be processed into satisfactory pipe end slope-mouth.
Ultrasonic inspection II: the steel pipe inner and outer welding behind hole enlargement, the hydraulic pressure and heat affected area, weld seam both sides part are carried out 100% inspection, to get rid of hole enlargement, the issuable defective of hydraulic pressure.
X-ray examination II: the steel pipe inner and outer welding behind hole enlargement, the hydraulic pressure is carried out 100% industrial television inspection and pipe end film making inspection, to get rid of hole enlargement, the issuable defective of hydraulic pressure.
Pipe end magnetic particle inspection: in case of necessity pipe end is carried out magnetic particle inspection.
Anticorrosion and coating: qualified steel pipe carries out anticorrosion and coating according to customer requirements on inspection.
Table 1 steel pipe Erichsen test result
R
t0.5 MPa
|
R
m ?MPa
|
R
t0.5/Rm
|
A
50 %
|
Uniform elongation % |
Remarks |
479 |
607 |
0.79 |
58.0 |
/ |
Horizontal sample |
485 |
587 |
0.83 |
56.0 |
11.0% |
Longitudinal test piece |
/ |
615 |
/ |
/ |
/ |
Welding point |
Table 2 Charpy-type test result
Table 3 DWTT section of shear rate (0 ℃)
Table 4 hardness test result (HV10)