CN101304823A - Method of manufacturing electric resistance welded tube with excellent weld characteristic - Google Patents
Method of manufacturing electric resistance welded tube with excellent weld characteristic Download PDFInfo
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- CN101304823A CN101304823A CNA2006800407469A CN200680040746A CN101304823A CN 101304823 A CN101304823 A CN 101304823A CN A2006800407469 A CNA2006800407469 A CN A2006800407469A CN 200680040746 A CN200680040746 A CN 200680040746A CN 101304823 A CN101304823 A CN 101304823A
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Abstract
Provided is a method of manufacturing an electric resistance welded tube which can provide an electric resistance welded tube with excellent weld characteristics by forming its lateral end part in a proper shape immediately before the electric resistance welding to surely remove penetrators during electric resistance welding. A predetermined taper shape is given to the lateral end part of a band material by transferring a fin shape in a finpass forming onto the lateral end part of the band material.
Description
Technical field
The needs that the present invention relates to a kind of manufacturing such as the line pipe that is used for oil well have the pipe of welding toughness or have the method for the pipe of weld strength such as the needs of the sleeve pipe that is used for oil well.
Background technology
Generally speaking, pipe can roughly be divided into welded pipe and seamless pipe.Make the sheet material circumflexion, make each edge butt joint and weld and make then by rollforming etc. as a kind of electrical resistance welding tube of welded pipe.In welded pipe, the toughness of welding and intensity are usually than the toughness and the intensity difference of master tape material.In any situation of using pipe, problem is to guarantee certain toughness and intensity at every kind of application.
For example, because be used to transport crude oil or the pipeline of natural gas is laid on colder area usually, so mainly will consider the toughness under the low temperature.And in order to protection being used for for the sleeve pipe of crude oil extraction in the oil well, what consider emphatically is intensity.
Usually, consider the master tape material after pipe manufacturer characteristic and the hot rolling sheet (band) of the master tape material that will become electrical resistance welding tube is carried out to the branch design, or it is heat-treated, thereby guarantees the characteristic such as toughness and intensity of master tape material.
Yet, because the characteristic of weld seam will be subjected to the composition design or the heat treated influence of welding method rather than master tape material to a great extent, so importantly improve solder technology.
The oxide that is called as burning is the defective reason of resistance welded, and these burning are created on the edge of welding sheet material.In many cases, burning can not arranged from above-mentioned edge along with molten steel in the resistance welded process, but remains on the above-mentioned edge, and the burning that left behind reduces toughness, causes insufficient strength.
Therefore, in order to remove burning, carried out conscientiously research so far at the technology of initiatively discharging molten steel from the transverse edge of band to be welded welding from welding portion.For example, patent documentation 1 or patent documentation 2 have been described the example of the shape at each edge of studying band.In this example, will be before carrying out resistance welded, to usually handling, make the shape after transverse edge treated can improve the discharge of the molten steel in the welding process by the shape of transverse edge of cutting or the edge planing is configured as the band of essentially rectangular.It below is general introduction.
That is, figure 1 illustrates the basic production line of electrical resistance welding tube.This electrical resistance welding tube production line has following structure,, launches band 10 from uncoiler 1 that is; It is smooth by finisher 2 band to be flattened again then; Make band 10 become circle gradually by rollforming machine 4 subsequently; Two transverse edges carry out resistance welded about then utilizing resistance welding machine to circular band 10, thereby band is configured as pipe 30, and this resistance welding machine comprises eddy-current heating part 5 and compression roller (resistance welded part) 6; Pass through the weld seam part of weld seam bite 7 cutting tubes 30 then; Regulate the external diameter of cutting back pipe 30 subsequently by sizing mill 8; Then pipe is cut into predetermined length by pipe cutting machine 9.Rollforming machine 4 has finned blade forming (finpassforming) stand 3 of predetermined quantity, described finned blade forming stand 3 in the end phase constraint Cheng Yuan strip edge, make it be configured as circular, comprise the first stand 3a and the second stand 3b in the stand 3.
In the technology described in the patent documentation 1, as show Fig. 5 A of cross-sectional view with shown in Fig. 5 B that shows its fragmentary detail view, in the finned blade forming first stand 3a, a feasible part that is shaped as the transverse edge of tubular band 10 contacts with the fin of fin hole shape roller, thereby be shown in as Fig. 5 C on the transverse edge at the edge that will become the inner surface side of pipe place and be configured as convergent shape, and shown in Fig. 5 D of showing cross-sectional view and Fig. 5 E of showing its fragmentary detail view, in the finned blade forming second stand 3b, make another part contact fin of the transverse edge of band 10, thereby be shown on the transverse edge that will become the outer surface of pipe side place as Fig. 5 F and be configured as convergent shape, thereby form the X-shaped groove.The angle of the fin of each stand among finned blade forming first stand 3a and the finned blade forming second stand 3b is an angle normally.
In patent documentation 2 described technology, as show shown in Fig. 6 A of cross-sectional view, upstream side at finned blade forming is provided with edger roll 11, and adopt edger roll 11 to reduce the transverse edge that is shaped as tubular band 10, thereby be configured as convergent shape integratedly on the transverse edge as Fig. 6 band that B is shown in 10, and as show Fig. 6 C of cross-sectional view and show shown in Fig. 6 D of its fragmentary detail view, in finned blade forming stand 3, make the fin of part contact fin hole shape roller of transverse edge of band 10, thereby shown in Fig. 6 E, make the transverse edge at the edge that will become the outer surface of pipe side place be configured as vertical surface.Patent documentation 3 to 5 is described the example that the shape of strip edge is studied.That is, make before rollforming usually by the strip edge of cutting or the edge planing is configured as essentially rectangular becomes convergent shape, makes that the edge shape after handling can improve the discharge of molten steel in the resistance welded process.
Patent documentation 1:JP-A-57-031485
Patent documentation 2:JP-A-63-317212
Patent documentation 3:JP-A-2001-170779
Patent documentation 4:JP-A-2001-259733
Patent documentation 5:JP-A-2003-164909
Yet the inventor has studied in the patent documentation 1 method of describing, even found that the upsetting amount that greatly changes in the finned blade forming, only makes the fin of part contact fin hole shape roller at edge of band 10 also quite difficult.Its reason is, because during shaping is formerly handled, the processed a little sclerosis of the transverse edge of band 10, thus the whole transverse edge of band is out of shape along fin easily, thereby fill the fin part admirably, thus with the shape transferred thereon of fin to the transverse edge of band.As a result, before being about to resistance welded, the transverse edge of band 10 is not in required shape, and under opposite extreme situations, transverse edge only is in and is under the even shape of inclination in a side.
And the inventor has studied the method described in the patent documentation 2, and the result has confirmed following situation.Promptly, for in rollforming (at the upstream side of finned blade forming stand) utilize edger roll 11 on the whole transverse edge of band 10, to form convergent shape, because need carry out the shaping described in patent documentation 2 with the edger roll that diameter the pipe internal surface side and increased gradually from the tube outer surface side direction, thereby by this edger roll the transverse edge at the edge that will become pipe internal surface side place is planed, this may cause the pad that is called " palpus " with being a problem.And, because on the cross-sectional direction of the band 10 for the treatment of rollforming, be applied with the big reaction force of outwards opening tubulose band 10, thereby be necessary to reduce pressure between the transverse edge of edger roll 11 and band 10.The result, as in the patent documentation 1, band is the processed hardly sclerosis by the reduction of transverse edge under the effect of edger roll, even and the upsetting amount reduces in finned blade forming subsequently, therefore band also can fully be filled the fin part, and difficulty is, and is described like that with the transverse edge shaping of band 10 as patent documentation 2, therefore convergent shape complete obiteration, and the edge becomes smooth.
Summary of the invention
Make the present invention at above situation, and the object of the present invention is to provide the method for making electrical resistance welding tube, wherein before being about to carry out resistance welded, can make the shape of transverse edge be shaped as suitable shape, thereby in the resistance welded process, fully discharge molten steel, thereby remove burning reliably, thereby can obtain to have the electrical resistance welding tube of splendid weld seam characteristic.
As mentioned above, in the prior art described in patent documentation 1 or 2, the part of the transverse edge of band is compressed against on the fin of finned blade forming roller, thereby the transverse edge of band is configured as convergent shape.Yet according to research, the inventor recognizes, even the finned blade forming roller does not have the complete filling band in a circumferential direction, in the time of still in band being loaded into fin hole shape roller, transverse edge is pushed by force by fin, thereby the fin part is filled transverse edge admirably.Be that the inventor recognizes, when band being loaded in the finned blade forming roller, the lateral center part (part of the lower face of tubular band) that is in relative about 180 degree positions with the transverse edge part with the transverse edge part fin contact and band band is in the state of beam deflection, thereby be applied with big band reaction force, it is bowed shape that this reaction force is used to make the cross sectional curve of tubular band, therefore, even band is not filled fin hole shape roller, also can on the transverse edge of circumferencial direction, be applied with big compression stress at band, the result, the transverse edge of band is pushed by force by fin, so the shape of fin directly is transferred to the transverse edge of band.
Therefore, the inventor notices such phenomenon, that is, the transverse edge of band is pushed by force by fin in finned blade forming, and has imagined by utilizing this phenomenon on one's own initiative the method that forms predetermined convergent shape on the transverse edge of band.Promptly, the inventor finds, when fin is shaped as the convergent shape with two or more stages, even the upsetting amount is little in finned blade forming, the transverse edge of band also can be shaped as required convergent shape, and therefore the transverse edge of band can be shaped as suitable convergent shape before being about to carry out resistance welded.
And patent documentation 5 discloses the various shapes of cutting sth. askew that help regulating contact pressure.Yet, burning is discharged this point and is carried out any description by this point that such burning discharge improves weld seam characteristic (particularly low-temperature flexibility) along with molten steel.Therefore, unclear fully is that any shape can be improved the characteristic (particularly low-temperature flexibility) of weld seam in the wherein disclosed various shapes of cutting sth. askew.
The present invention is based on above consideration, and have following feature.
1. a manufacturing has the method for the electrical resistance welding tube of splendid weld seam characteristic, it is characterized in that: therein band is formed and makes edge butt joint and weld with in the process that forms pipe by resistance welded, before carrying out described resistance welded with the upper face side of described band or below the edge shaping at upper and lower surface side place of the edge at any side place of side or described band be convergent shape.
2. a manufacturing has the method for the electrical resistance welding tube of splendid weld seam characteristic, it is characterized in that: in the finned blade forming that rollforming is handled, the fin shape that employing has two or more angles with described shape transferred thereon on strip edge, on described edge, to form convergent shape.
3. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to above 1 or 2 described manufacturings, it is characterized in that: the edge at a side place is for circular on the thickness direction of described band.
4. has the method for the electrical resistance welding tube of splendid weld seam characteristic according to above 1 to 3 described manufacturing, it is characterized in that: the edge at the internal side diameter place of described band is shaped as convergent shape in the previous stage of finned blade forming, and the edge at the outside diameter place of described band is shaped as convergent shape in the latter half of finned blade forming.
5. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to above 1 to 4 described manufacturing, it is characterized in that: in the finned blade forming that comprises fin end stand at least, be convergent shape described edge shaping.
6. has the method for the electrical resistance welding tube of splendid weld seam characteristic according to above 1 to 5 described manufacturing, it is characterized in that: after finned blade forming in the convergent shape of described band, angle from the surface of strip edge towards vertical direction is spent in the scopes of 50 degree 25, and the length of perpendicular from the starting position that is shaped as convergent shape to end position is 20% to 45% of a thickness at a side place.
7. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to above 1 to 6 described manufacturing, it is characterized in that: when being blown into non-active gas or reducibility gas, carry out resistance welded.
8. 1 to 7 described manufacturing has the method for the electrical resistance welding tube of splendid weld seam characteristic according to part, it is characterized in that: the butt joint angle between the sheet material edge for from-1 spend+carry out resistance welded under the situation of 1 degree.
9. 1 to 8 described manufacturing has the method for the electrical resistance welding tube of splendid weld seam characteristic according to part, it is characterized in that: carry out resistance welded at the V word angle that is shaped by strip edge for spending under the situation of 8 degree from 2.
Description of drawings
Fig. 1 is the key diagram of the production line of electrical resistance welding tube;
Fig. 2 A, 2B and 2C are the figure that is used to illustrate first embodiment of the present invention;
Fig. 3 A, 3B and 3C are the figure that is used to illustrate second embodiment of the present invention;
Fig. 4 A to 4F is the figure that is used to illustrate the 3rd embodiment of the present invention;
Fig. 5 A to 5F is the figure of diagram prior art (technology of describing in the patent documentation 1);
Fig. 6 A to 6E is the figure of another prior art of diagram (technology of describing in the patent documentation 2);
Fig. 7 is the schematic diagram that shows example according to the embodiment of the present invention, wherein under the heating of resistance welded non-oxidizing gas is blown on the strip edge;
Fig. 8 is the schematic diagram that shows example according to the embodiment of the present invention, and the periphery that wherein will be in the strip edge under the heating of resistance welded remains under the atmosphere of non-oxidizing gas;
Fig. 9 shows the figure that was in the band that is shaped as convergent shape under the relative conditon before being about to carry out resistance welded;
Figure 10 shows the figure that was in the prior art band with rectangular edges under the relative conditon before being about to carry out resistance welded;
Figure 11 is the figure that shows the V-arrangement angle that is about to begin the band that is shaped as convergent shape before the resistance welded; And
Figure 12 is the figure that shows the V-arrangement angle that is about to begin the prior art band with rectangular edges before the resistance welded.
Reference numeral
1 uncoiler
2 finishers
3 finned blade forming stands
3a finned blade forming first stand
3b finned blade forming second stand
4 rollforming machines
5 induction heating equipments
6 compression rollers (resistance welded part)
7 weld seam bites
8 sizing mills
9 pipe cutting machines
10 bands
20 are tubular sheet material
30 pipes
The direction of advance of 40 bands 10 (being pipe 30) in the welding postforming
End above 50 contacts
60 gas supply nozzles
The specific embodiment
Preferred implementation of the present invention is described now with reference to the accompanying drawings.
Fig. 1 shows the production line of the electrical resistance welding tube of using among the present invention.That is, this production line of electrical resistance welding tube has following structure, wherein, launches band 10 from uncoiler 1; It is smooth by finisher 2 band to be flattened again then; Make band 10 become circle gradually by rollforming machine 4 subsequently; Two transverse edges carry out resistance welded about then utilizing resistance welding machine to circular band 10, thereby band is shaped as pipe 30, and this resistance welding machine comprises eddy-current heating part 5 and compression roller (resistance welded part) 6; Pass through the weld seam part of weld seam bite 7 excision pipes 30 then; Regulate the external diameter of cutting back pipe 30 subsequently by sizing mill 8; Then pipe is cut into predetermined length by pipe cutting machine 9.Rollforming machine 4 has the finned blade forming stand 3 of predetermined quantity, described finned blade forming stand will on last stage the sheet material edge constraint of Cheng Yuan be circular, comprise the first stand 3a and the second stand 3b in this stand 3.
In the first embodiment, although as show Fig. 2 A of cross-sectional view with shown in Fig. 2 B that shows its fragmentary detail view, the fin of the finned blade forming first stand 3a has a common stage convergent shape, (taper angle of second stage is α but the fin of second stage stand 3b has two stage convergent shape, and the inclination vertical length of second stage is β), and such shape be transferred to band 10 about two transverse edges, thereby shown in Fig. 2 C, about a side place of the outer surface side that will become pipe two transverse edges be shaped as and have predetermined convergent shape (inclination angle from transverse edge to the surface that will become tube outer surface is α, and the starting position on the transverse edge and will become that the distance on thickness direction is β between the surface of tube outer surface).
Make band 10 about the convergent shape that is shaped on two transverse edges for like this, promptly, inclined angle alpha from the transverse edge of band 10 to the surface that will become tube outer surface is in 25 ° to 50 ° scope, and the convergent shape starting position on the transverse edge and will become that the distance beta of band on thickness direction is 20% to 40% of thickness of strip between the surface of tube outer surface.
This be because, in inclined angle alpha during less than 25 °, molten steel can be not fully middle body from the thickness of strip discharge, and stay burning defectively, cause resistance welded to finish back toughness or intensity reduction, and in inclined angle alpha during greater than 50 °, debatable is that convergent shape still is left on the production tube as defective after resistance welded finishes.And, in distance beta 20% o'clock less than thickness, molten steel can not be fully middle body from the thickness discharge, thereby be tending towards staying burning, and in distance beta 40% o'clock greater than thickness, debatable is that convergent shape still is left on the production tube as defective after resistance welded finishes.
As mentioned above, in the present embodiment, make that the fin shape of finned blade forming end stand 3b is the convergent shape with two angles, and with fin shape be transferred to band 10 about on two transverse edges, thereby can before being about to carry out resistance welded, make the shape of each transverse edge of band 10 be configured as suitable convergent shape.As a result, in the resistance welded process, can discharge molten steel fully, and can remove burning reliably, therefore the electrical resistance welding tube that can obtain to have splendid weld seam characteristic.
More than, can make by the shape that changes described two stage convergent shapes the side place that will become pipe inner peripheral surface side about two transverse edges be shaped as predetermined convergent shape.
In another embodiment of the present invention, although the fin of the finned blade forming first stand 3a has a common stage convergent shape, but as show Fig. 3 A of cross-sectional view with shown in Fig. 3 B that shows its fragmentary detail view, the fin of the second stand 3b has three stage convergent shapes, and (phase I inclination vertical length is δ, the second stage taper angle is γ, the phase III taper angle is α, and phase III inclination vertical length is β), and such shape be transferred to band 10 about two transverse edges, thereby shown in Fig. 3 C, will become the tube outer surface side a side place about two transverse edges be shaped as predetermined convergent shape (inclination angle from transverse edge to the surface that will become tube outer surface be α, and the starting position on the transverse edge and will become that the distance on thickness direction is β between the surface of tube outer surface), and will become the pipe internal surface side a side place about two transverse edges be configured as and have predetermined convergent shape (inclination angle from transverse edge to the surface that will become pipe internal surface is γ, the starting position on the transverse edge and will become that the distance on thickness direction is φ between the surface of pipe internal surface).Yet, when an angle in the angle of described three stage fins during greater than in vertical direction angle of fin roller, by the transverse edge of fin planing band, this can cause being called the pad of " palpus ", cause in the finned blade forming process, producing defective, perhaps in resistance welded, cause spark.Therefore, the angle of fin preferably is not more than fin roller angle in vertical direction.
Make band 10 about the convergent shape that is shaped on two transverse edges for like this, promptly, inclined angle alpha from the transverse edge of band 10 to the surface that will become tube outer surface, and the inclination angle γ from transverse edge to the surface that will become pipe internal surface is respectively 25 ° to 50 °, and the convergent shape starting position on the transverse edge and will become the distance beta on the thickness of strip direction between the surface of tube outer surface, and convergent shape starting position and will become between the surface of pipe internal surface and on the band vertical direction, be respectively 20% to 40% of thickness of strip apart from φ.
This be because, at inclined angle alpha or γ during less than 25 °, molten steel can be not fully middle body from the thickness of strip discharge, and stay burning defectively, cause resistance welded to finish back toughness or intensity reduction, and during greater than 50 °, debatable is that convergent shape still is left on the production tube as defective after resistance welded at inclined angle alpha or γ.And, begin distance beta or φ 20% o'clock convergent shape less than thickness, molten steel can not be fully middle body from the thickness of strip discharge, thereby be tending towards staying burning, and begin distance beta or φ 40% o'clock greater than thickness convergent shape, debatable is that convergent shape still is left on the production tube as defective after resistance welded finishes.
As mentioned above, in the present embodiment, make the fin shape of finned blade forming end stand 3b become shape with three angles, and with fin shape be transferred to band 10 about on two transverse edges, thereby can before being about to carry out resistance welded, make the shape of each transverse edge of band 10 be shaped as suitable convergent shape.As a result, in the resistance welded process, can discharge molten steel fully, and can remove burning reliably, therefore the electrical resistance welding tube that can obtain to have splendid weld seam characteristic.
In an embodiment more of the present invention, as show Fig. 4 A of cross-sectional view and show shown in Fig. 4 B of its fragmentary detail view, the fin of the finned blade forming first stand 3a in previous stage has two stage convergent shape (the inclination vertical length δ of phase I and phase I taper angle γ), and with this shape transferred thereon to about the band 10 on two transverse edges, thereby shown in Fig. 4 C, will become the pipe internal surface side a side place about two transverse edges be configured as predetermined convergent shape (inclination angle from transverse edge to the surface that will become pipe internal surface is γ, and the starting position on the transverse edge and will become that the distance on thickness direction is φ between the surface of inner surface of pipe).In addition, as show Fig. 4 D of cross-sectional view and show shown in Fig. 4 E of its fragmentary detail view, the fin of the finned blade forming second stand 3b in the latter half has two stage convergent shape (the second stage taper angle is that α and second stage inclination vertical length are β), and with this shape transferred thereon to about the band 10 on two transverse edges, thereby shown in Fig. 4 F, will become the tube outer surface side a side place about two transverse edges be configured as predetermined convergent shape (inclination angle from transverse edge to the surface that will become tube outer surface is α, and the starting position on the transverse edge and will become that the distance on thickness direction is β between the surface of outer surface of pipe).
When making each transverse edge at a side place of the inner surface that will become pipe all be configured as convergent shape by the finned blade forming first stand 3a, the part that is formed is under the effect of strong pressure and by work hardening significantly, even thereby transverse edge further is shaped as convergent shape by finned blade forming end stand 3b, the convergent shape that is shaped by the first stand 3a can not damaged by pressure relatively yet.Therefore, after finned blade forming finishes, can be in the inner surface side of pipe and outer surface side the transverse edge of band be configured as predetermined convergent shape.
Make band 10 about the convergent shape that is shaped on two transverse edges for like this, promptly, inclined angle alpha from the transverse edge of band 10 to the surface that will become tube outer surface, and the inclination angle γ on the surface from transverse edge to the inner surface that will become pipe is respectively 25 ° to 50 °, and the convergent shape starting position on the transverse edge and will become the distance beta on the thickness of strip direction between the surface of outer surface of pipe, and convergent shape starting position and will become between the surface of inner surface of pipe and on the thickness of strip direction, be respectively 20% to 40% of thickness of strip apart from φ.
This be because, at inclined angle alpha or γ during less than 25 °, molten steel can be not fully middle body from the thickness of strip discharge, and stay burning defectively, cause resistance welded to finish back toughness or intensity reduction, and during greater than 50 °, debatable is that convergent shape still is left on the production tube as defective after resistance welded at inclined angle alpha or γ.And, begin distance beta or φ 20% o'clock convergent shape less than thickness, molten steel can not be fully middle body from the thickness discharge, and be tending towards staying burning, and in distance beta or φ 40% o'clock greater than thickness, debatable is that convergent shape still is left on the production tube as defective after resistance welded finishes.
As mentioned above, in the present embodiment, finned blade forming is performed such, promptly, make the fin shape of the first stand 3a of previous stage and the fin shape of the second stand 3b of the latter half become the shape that comprises two angles, and with each fin shape be transferred to band 10 about on two transverse edges, thereby before being about to carry out resistance welded, the transverse edge of band 10 can be shaped as suitable convergent shape.As a result, in the resistance welded process, can discharge molten steel fully, and can remove burning reliably, therefore the electrical resistance welding tube that can obtain to have splendid weld seam characteristic.
In first to the 3rd embodiment, the transverse edge that is positioned at tube outer surface side and/or pipe internal surface side place of band by finned blade forming end stand (here, the second stand 3b) reason that is configured as convergent shape is, because resistance welded is being carried out thereafter at once, thereby can under the situation that keeps splendid convergent shape, carry out resistance welded.Yet, also acceptablely be, the beginning stand by finned blade forming or the middle stand of finned blade forming and not the end stand by finned blade forming the transverse edge of band is configured as convergent shape.In case the transverse edge of band is shaped as convergent shape, just quilt work hardening significantly under strong pressure of transverse edge, even thereby be carried out finned blade forming after the transverse edge, convergent shape also is difficult to be damaged by pressure relatively, therefore, even after finned blade forming finishes, the state that also still can keep transverse edge wherein to be shaped as convergent shape.
And, in the present invention, because only with the mode of finned blade forming as formation convergent shape, thus need be such as the equipment of edger roll or planing roller, therefore need not to change the roller or the planing stone that are used for them, thereby can make electrical resistance welding tube effectively with splendid welding quality.
Here, in this method that forms convergent shape by finned blade forming, be difficult to after resistance welded finishes, improve the toughness or the intensity of welding sometimes.
By studying the reason of this point in great detail, in resistance welded, in pressure welding (upsetting) stage to the strip edge heating before, may on strip edge, form oxide, these oxides cause the burning as weld defect.These oxides float on the surface of weldable steel, described weldable steel in the melting stage of each strip edge, be melted and stage of pressure welding along with molten steel is partly discharged.At this moment, if strip edge is shaped as convergent shape, then molten steel is discharged from easily, in addition, can effectively discharge burning.
Yet, because produce along with the heating of resistance welded as the oxide on the strip edge in burning source, thereby produce following situation sometimes under some welding condition cumulatively: toughness after the welding or intensity can not only fully be improved by form convergent shape on strip edge.
Therefore, the inventor has observed the phenomenon of resistance welded once more in detail, and the result notices that the generation of oxide is the reason of burning.That is, they have not only been studied by form convergent shape on strip edge and have discharged burning, but also have studied the generation that prevents as the oxide of burning reason.
As a result, the inventor recognizes, when when each strip edge is blown non-oxidizing gas, suppressing the generation of oxide (that is, the melt-edge for the treatment of the pressure welding before the pressure welding heats) under the situation of resistance welded heating.Here, non-oxidizing gas refers to non-active gas (nitrogen, helium, argon gas, neon, xenon etc., or by inciting somebody to action wherein at least two kinds of mists that mixed to form), reducibility gas (hydrogen, CO gas, methane gas, propane gas etc., or by will be wherein at least two kinds of mists that mixed to form), perhaps non-active gas and reducibility gas are mixed and the mist that forms.
That is, in the present invention, before carrying out resistance welded, formerly each strip edge is configured as convergent shape, thereby quickens the discharge of burning, in addition, blow non-oxidizing gas to strip edge under the heating state in the resistance welded process, thereby suppress generation as the oxide of burning reason.Compare with the level of prior art, this can guarantee to improve welding toughness and intensity.Yet when just blowing non-oxidizing gas, the effect that the inhibition oxide produces on strip edge can more or less decrease because surrounding air is absorbed.Therefore, prevent that preferably surrounding air is absorbed.For this reason, preferably surround the strip edge under the resistance welded heating, thereby this ambient inboard remains under the non-oxidizing gas atmosphere.
In the non-oxidizing gas of these kinds, more preferably use the gas that contains reducibility gas, this is because can further increase the effect of inhibition as the oxide generation of burning reason, thereby can improve the toughness or the intensity of welding more significantly.
Availability and reduce cost aspect, preferred adopt following gas as non-oxidizing gas.
Using separately under the situation of non-active gas: (A) any in nitrogen, helium and the argon gas, or at least two kinds mist in them.
Using separately under the situation of reducibility gas: (B) a kind of in hydrogen or the CO gas, or the mist of these two kinds of gases.
Under the situation of the mist that uses non-active gas and reducibility gas: above-mentioned (A) and mist (B).Obviously, particularly when use contains the gas of hydrogen and/or CO gas, should take absolute safety measure.
And, in order to handle this problem, the inventor has at length observed the resistance welded phenomenon once more, and the result notices the butt joint corner between two edges on the strip width direction (angle between the vertical surface at two edges on the strip width direction) in the resistance welded process.That is, the inventor finds, except forming on each strip edge the convergent shape, vertically the butt joint corner between the surface be not shaped as convergent shape also to a large extent with burning along with effective discharge of molten steel is relevant.
In resistance welded, when the butt joint corner between the vertical surface that changes strip edge (the vertical edge of band), the discharge pattern of molten steel is changed.Promptly, be set to when the tube outer surface side is opened at this butt joint corner, each strip edge that is shaped as convergent shape can make preferential heating tube inner surface side, thereby molten steel can at first produce in the pipe internal surface side, and when each strip edge was little by little docked, molten steel can progressively be discharged to the tube outer surface side in the resistance welded process.Be set to when the pipe internal surface side is opened at this butt joint corner, each strip edge that is shaped as convergent shape can make preferential heating tube outer surface side, thereby molten steel can at first produce in the tube outer surface side, and when each strip edge was little by little docked, molten steel can progressively be discharged to the pipe internal surface side in the resistance welded process.
At this moment, for example, the butt joint corner of opening towards tube outer surface when hypothesis for just and the butt joint corner of opening towards inner surface side when negative, if this butt joint corner is big, greater than+1 ° or less than-1 °, then because the strip edge at a side place is preferentially melted, thereby the amount of molten steel that will flow to the strip edge at opposite side place can significantly increase, molten steel can not fully be discharged at weld period before finishing butt joint, so resistance welded also has molten steel to be limited in the band when finishing.As a result, gather in the molten steel or gather its lip-deep burning and be left in the band, cause the toughness of resistance welded or intensity significantly to descend.From as can be known above, the vertical surface between the edge of the band in the resistance welded need be in ± 1 ° (1 ° to+1 °).
At this moment, when each strip edge is configured as convergent shape in advance, at first the fusing amount at Rong Hua a edge will reduce, the amount that reduces is corresponding to this volume that reduces, and this edge melts along described convergent shape, therefore thereby molten steel further reduces, and can discharge burning from resistance welded fully by the two effect of butt joint angle and convergent shape, causes the remarkable improvement of toughness and intensity.
Above-mentioned embodiment of the present invention below will be described.
Fig. 1 is the figure that shows the production line of the electrical resistance welding tube of using in embodiments of the present invention.The production line of this electrical resistance welding tube has such essential structure, promptly wherein, launches band 10 from uncoiler 1; It is smooth by finisher 2 band to be flattened again then; Make band 10 become circle gradually by rollforming machine 4 subsequently; Then utilize resistance welding machine to become circular band 10 about two transverse edges carry out resistance welded, thereby band is configured as pipe 30, this resistance welding machine comprises eddy-current heating part 5 and compression roller (resistance welded part) 6; Pass through the weld seam part of weld seam bite 7 excision pipes 30 then; Regulate the external diameter of cutting back pipe 30 subsequently by sizing mill 8; Then will manage 30 by pipe cutting machine 9 is cut into predetermined length.
In this embodiment, rollforming machine 4 has and (for example comprises a plurality of stands in the stage in the end, three stands) finned blade forming stand 3, and as mentioned above, the fin of each stand all is shaped as suitable shape, thereby the following side of the upper face side of each strip edge (inner surface side of pipe) and/or each strip edge (the outer surface side of pipe) can be shaped as predetermined convergent shape.
For example, as show Fig. 2 A of cross-sectional view with shown in Fig. 2 B that its fragmentary detail view is shown, the optional stand of finned blade forming stand 3 has the fin shape (the second stage taper angle is α, and second stage inclination vertical length is β) of two predetermined stage convergent shapes.Such fin shape is transferred on the transverse edge of band 10, thus the following side of band 10 (the outer surface side of pipe) locate about two transverse edges to be shaped as taper angle be that α and convergent height are the convergent shape of β.
By with upper type, as shown in Figure 9, to be shaped as taper angle be that α and convergent height are the convergent shape of β and to be shaped as taper angle in inner surface side be that γ and convergent height are that the tubular band 20 of the convergent shape of δ is provided so that butt joint corner θ between the vertical surface of strip edge for from-1 ° to+1 °, is used for resistance welded to face side outside.
Therefore, can discharge burning fully, thereby can obtain to have the electrical resistance welding tube of splendid toughness and intensity from resistance welded.
And, in order to handle above problem, the inventor has at length observed the resistance welded phenomenon once more, and the inventor notices as a result, the upper corners in the V-arrangement (V font) that formed in a longitudinal direction by two edges on the strip width direction before being about to carry out resistance welded.That is, the inventor finds, except forming on each strip edge the convergent shape, this V font also on sizable degree with burning along with effective discharge of molten steel is relevant.
In resistance welded, when changing the V word angle of each strip edge shaping, the generation of molten steel/discharge pattern is changed.Promptly, at V word angle hour, strip edge begins to be heated in the position away from welding portion, and at hot spot during near welding portion, the temperature of strip edge will rise gradually, and heating is diffused into central part on the strip edge thickness in the upper and lower from the thickness gradually.When molten steel produces gradually along with the propelling of this phenomenon, before the molten steel of locating to produce in the bottom (pipe internal surface side) on the top on the thickness of strip edge (tube outer surface side) and the thickness arrives welding portion, just begin to solidify, therefore be difficult to the molten steel in the central part on the thickness is discharged to the outside.As a result, the burning that produces along with molten steel is tending towards being left in the band, causes resistance welded toughness or intensity significantly to reduce.
Therefore, the inventor has done conscientiously research to V word angle, and result, inventor recognize, if V word angle be 2 ° or more than, then can discharge molten steel capitally, improve welding toughness or intensity.
Yet, if V word angle too increases, then welding portion can fully not heated, thereby the temperature of strip edge is difficult to raise, therefore produce that each edge wherein is called as the oxidation film covering of weld oxide fully and the state that do not produce molten steel, the toughness or the intensity that cause welding significantly reduce.For it is handled, the inventor recognizes, if V word angle is 8 ° or littler, then can prevent to weld oxide.
At this moment, when each strip edge is configured as convergent shape in advance, at first the fusing amount at Rong Hua a edge will reduce, the amount that reduces is corresponding to this volume that reduces, and fusing advances along described convergent shape, therefore thereby molten steel is further reduced, and can discharge burning from resistance welded fully by the two effect of V word angle and convergent shape, significantly improves toughness and intensity.
Above-mentioned embodiment of the present invention below will be described.
Fig. 1 is the figure that shows the production line of the electrical resistance welding tube of using in embodiments of the present invention.The production line of this electrical resistance welding tube has such essential structure, promptly wherein, launches sheet material (band) 10 from uncoiler 1; It is smooth by finisher 2 band to be flattened again then; Make band 10 become circle gradually by rollforming machine 4 subsequently; Then utilize resistance welding machine to become circular band 20 about two transverse edges carry out resistance welded, thereby band is configured as pipe 30, this resistance welding machine comprises eddy-current heating part 5 and compression roller (resistance welded part) 6; Pass through the weld seam part of weld seam bite 7 excision pipes 30 then; Regulate the external diameter of cutting back pipe 30 subsequently by sizing mill 8; Then will manage 30 by pipe cutting machine 9 is cut into predetermined length.
In this embodiment, rollforming machine 4 has in the end, and the stage (for example comprises a plurality of stands, three stands) finned blade forming stand 3, and as mentioned above, the fin of each stand all is shaped as suitable shape, thereby the following side of the upper face side of each strip edge (inner surface side of pipe) and/or each strip edge (the outer surface side of pipe) can be shaped as predetermined convergent shape.
For example, as show Fig. 2 A of cross-sectional view with shown in Fig. 2 B that its fragmentary detail view is shown, the optional stand of finned blade forming stand 3 has the fin shape (the second stage taper angle is α, and second stage inclination vertical length is β) of two predetermined stage convergent shapes.Such fin shape is transferred on the transverse edge of band 10, thus the following side of band 10 (the outer surface side of pipe) locate about two transverse edges to be shaped as taper angle be that α and convergent height are the convergent shape of β.
By with upper type, as shown in figure 11, outside face side be shaped as taper angle be α and convergent height be β convergent shape and inner surface side be shaped as taper angle be γ and convergent height be the tubular band 20 of the convergent shape of δ be provided so that V word angle φ be 2 ° to 8 °, be used for resistance welded.
Therefore, can discharge burning fully, thereby can obtain to have the electrical resistance welding tube of splendid toughness and intensity from resistance welded.
Embodiment
Embodiment 1
Below embodiment 1 will be described.
Here, adopting width is that 1920mm, thickness are that to make diameter be the electrical resistance welding tube of 600mm for the band (steel band) of 19.1mm.Downcut test pieces from the welding portion of the electrical resistance welding tube of having made, and this test pieces is carried out the performance of Charpy test with the assessment pipe.Do a Charpy test pieces sampling at each point in ten differences on the length of tube direction by this way, promptly, the longitudinal direction of test pieces is parallel to the pipe circumferencial direction, and the longitudinal center of recess is corresponding to the center on the thickness of welding portion.Test pieces is configured as JIS5 2 mm-V-recess shock-testing sheets, under-46 ℃, carries out shock-testing, and measure Charpy impact value and brittle fracture Surface factor.125J or above Charpy impact value and 35% or following brittle fracture Surface factor be appointed as the performance range of allowing respectively.
(embodiment of the invention 1)
As the embodiment of the invention 1, make electrical resistance welding tube according to first embodiment.That is, the band transverse edge that will become a side place of tube outer surface side is shaped as convergent shape by finned blade forming end stand, and the fin of this end stand has two angles (first angle of fin is 85 ° with respect to the vertical line of roll axis).The inclined angle alpha that makes this convergent shape is 30 ° with respect to the vertical edge of band.
(embodiment of the invention 2)
As the embodiment of the invention 2, make electrical resistance welding tube according to second embodiment.Promptly, in two stand finned blade formings, will become the band transverse edge at a side place of tube outer surface side and the band transverse edge that will become a side place of pipe internal surface side and be shaped as convergent shape by first stand respectively, the fin of this first stand has three angles (second angle of fin is 40 ° with respect to the vertical line of roll axis).Make that will become the inclined angle alpha at a side place of tube outer surface side is 25 ° with the inclination angle γ that will become a side place of pipe internal surface side.
(embodiment of the invention 3)
As the embodiment of the invention 3, make electrical resistance welding tube according to the 3rd embodiment.Promptly, in three stand finned blade formings, the band transverse edge that will become a side place of pipe internal surface side is shaped as convergent shape by first stand, the fin of this first stand has two angles (first angle of fin is 60 ° with respect to the vertical line of roll axis), and the band transverse edge that will become a side place of tube outer surface side is shaped as convergent shape by the 3rd stand, and the fin of the 3rd stand has two angles (first angle of fin is 85 ° with respect to the vertical line of roll axis).Make that will become the inclined angle alpha at a side place of tube outer surface side is 30 °, and the inclination angle γ that will become a side place of pipe internal surface side is 40 °.
(prior art embodiment 1)
As prior art embodiment 1, make electrical resistance welding tube according to the method described in the patent documentation 1.Promptly, in fin finned blade forming first stand with an angle, attempt to regulate the upsetting amount of fin, thereby the transverse edge of band is contacted on corresponding to the marginal portion of almost half thickness with fin, thereby make the transverse edge at a side place that will become the pipe internal surface side be shaped as convergent shape, and in fin finned blade forming second stand with an angle, the transverse edge that purpose is to make band contacts with fin on corresponding to the marginal portion of almost half thickness at remaining, thereby makes the transverse edge at a side place that will become the tube outer surface side be shaped as convergent shape.Make that the inclination angle of convergent shape is 20 °.
(prior art embodiment 2)
As prior art embodiment 2, make electrical resistance welding tube according to the method described in the patent documentation 2.Promptly, attempt edger roll is arranged on the upstream side of finned blade forming, and adopt this edger roll to reduce the transverse edge of band, thereby the transverse edge of band is configured as convergent shape on the whole, and in fin finned blade forming stand with an angle, purpose is to make the transverse edge of band to contact with fin on corresponding to the marginal portion of almost half thickness, thereby makes the transverse edge at a side place that will become the tube outer surface side be shaped as vertical surface.Make that the inclination angle of convergent shape is 20 °.
(prior art embodiment 3)
As prior art embodiment 3, in production line shown in Figure 1, the transverse edge polishing with band in advance is rectangle, and adopts fin finned blade forming stand with an angle to make electrical resistance welding tube.
Measurement is according to the Charpy impact value and the brittle fracture Surface factor of the welding portion of the electrical resistance welding tube of above manufacturing, and the result of measurement is shown in the table 1.And, be about to carry out before the resistance welded transverse edge with band and cut down and sample, observe the shape of described transverse edge, the result of these observations has also been described.
Table 1
| Convergent shape desired value in the finned blade forming | Convergent shape measured value before being about to resistance welded | The Charpy impact value | The brittle fracture Surface factor | ||
| The embodiment of the invention 1 | 30 ° at tube outer |
30 ° at tube outer surface side place | 150J | 25％ | |
| The embodiment of the |
25 ° at 25 ° of pipe internal surface sides place, tube outer surface side place | 25 ° at 25 ° of pipe internal surface sides place, tube outer surface side place | 180J | 15％ | |
| The embodiment of the |
40 ° at 30 ° of pipe internal surface sides place, tube outer |
40 ° at 30 ° of pipe internal surface sides place, tube outer surface | 200J | 10％ | |
| Prior art embodiment 1 | 25 ° at 25 ° of pipe internal surface sides place, tube outer surface side place | No convergent shape (smooth) | 25J | 51％ | |
| |
20 ° at pipe internal surface side place | No convergent shape (smooth) | |
50％ | |
| |
Be not provided with | Be not provided with | 20J | 58％ |
As known from Table 1, in the embodiment of the invention 1 to 3, welding portion has high impact strength and little brittle fracture Surface factor, that is, toughness is splendid, and the reliability of products height.On the contrary, in prior art embodiment 1 to 3, welding portion has low impact strength and big brittle fracture Surface factor, that is, toughness reduces, and reliability of products is low.And, when after finned blade forming, being about to carry out before the resistance welded mutually relatively the shape of the transverse edge of band, although in the embodiment of the invention 1 to 3, on the transverse edge at the transverse edge at a side place that will become the pipe internal surface side and a side place that will become the tube outer surface side, all keep required convergent shape, but transverse edge is smooth in finned blade forming, and does not keep convergent shape in prior art embodiment 1 and 2.
Therefore, confirmed the electrical resistance welding tube that can obtain to have splendid weld seam characteristic according to the present invention.
(embodiment of the invention 21)
The 3rd stand of the finned blade forming 3 by having three stands altogether is configured as roughly straight convergent shape (taper angle α and convergent degree of depth β are set to the value shown in the table 2) with the external diameter of pipe side of each strip edge, and in embodiment as shown in Figure 7, argon gas is blown on the edge of the band 10 of (resistance heated of end 50 above from contact) under the resistance welded heating from gas supply nozzle 60.In Fig. 7, the direction of advance of 40 expression bands 10 (being pipe 30) in the welding postforming, and omit the compression roller that does not illustrate.
(embodiment of the invention 22)
First stand of the finned blade forming 3 by having two stands altogether is configured as roughly straight convergent shape (taper angle α and convergent degree of depth β are set to the value shown in the table 2) with the external diameter of pipe side of each strip edge respectively, and second stand by finned blade forming is configured as roughly straight convergent shape with the external diameter of pipe side at edge, and in embodiment as shown in Figure 8, be enclosed in the edge of the band 10 under resistance welded heating when passing through with gas atmosphere case 13, and the inside of this case is remained on carbon monoxide is 1% along direction of advance 40, residue is in the atmosphere of nitrogen.In Fig. 8, the direction of advance of 40 expression bands 10 (being pipe 30) in the welding postforming, and omit the compression roller that does not illustrate.
(comparative example 21)
First stand of the finned blade forming 3 by having three stands altogether makes each strip edge all be shaped as roughly straight convergent shape (taper angle α and convergent degree of depth β are set to the value shown in the table 2) at the internal side diameter and the outside diameter place of pipe, and will all be retained as at each band under the resistance welded heating and be exposed in the air.
(prior art embodiment 21)
The shape of each strip edge is remained essentially rectangular (the longitudinal edge shape of rectangle), and will each band under resistance welded heating all be retained as and be exposed in the air.
Downcut test pieces from the welding portion of the steel pipe under above-mentioned four kinds of situations, made, and this test pieces is carried out the performance of Charpy test with the assessment pipe.Adopt JIS5 2 mm-V-recess shock-testing sheets as the Charpy test pieces, at each point in ten differences on the length of tube direction these test pieces are done once sampling by this way, promptly, the longitudinal direction of test pieces is taken on the pipe circumferencial direction, and the longitudinal center of recess is taken at the center position of welding portion on thickness, and under-46 ℃ temperature, carry out shock-testing, and measure Charpy impact value and brittle fracture Surface factor test pieces.125J or above Charpy impact value and 35% or following brittle fracture Surface factor be appointed as the performance range of allowing respectively.The result who measures is shown in the table 2.
As known from Table 2, in the embodiment of the invention 21 and 22, welding portion has high impact strength (Charpy impact value) and little brittle fracture Surface factor, that is, toughness is splendid, and the reliability of products height.On the contrary, in comparative example 21 and prior art embodiment 21, welding portion has low impact strength (Charpy impact value) and big brittle fracture Surface factor, that is, toughness reduces, and reliability of products is low.
Table 2
| The atmosphere of resistance welded | Form the method for convergent shape | Be about to welding edge convergent shape before | The Charpy impact value | The brittle fracture Surface factor | |
| The embodiment of the invention 21 | Be blown into argon gas | The 3rd stand of 3 stand finned |
α=25 ° β=4mm (thickness 21%) | |
12％ |
| The embodiment of the invention 22 | 1% carbon monoxide remains and is nitrogen | First and second stands that have the finned blade forming of two stands altogether | α=45 ° β=7mm (thickness 37%) | 310J | 7％ |
| The comparative example 21 | Air | First stand of 3 stand finned |
α=20 ° β=4mm (thickness 16%) | 130J | 33％ |
| Prior art embodiment 21 | Air | Shapeless | No convergent shape | 25J | 55％ |
Below embodiment 3 will be described.
Here, adopting width is that 1920mm, thickness are that to make diameter be the electrical resistance welding tube of 600mm for the band (steel band) of 19.1mm.
Downcut test pieces from the welding portion of the electrical resistance welding tube of having made, and this test pieces is carried out the performance of Charpy test with the assessment pipe.Do a Charpy test pieces sampling at each point in ten differences on the length of tube direction by this way, promptly, the longitudinal direction of test pieces is parallel to the pipe circumferencial direction, and the longitudinal center of recess is corresponding to the center of welding portion on thickness.Test pieces is configured as JIS5 2mm-V-recess shock-testing sheet, and under-46 ℃, carries out shock-testing, and measure Charpy impact value and brittle fracture Surface factor.125J or above Charpy impact value and 35% or following brittle fracture Surface factor be appointed as the performance range of allowing respectively.
(embodiment of the invention 31)
As the embodiment of the invention 31, make electrical resistance welding tube according to present embodiment.At this moment, carry out resistance welded by this way, promptly, the 3rd stand of the finned blade forming stand by comprising three stands is configured as roughly straight convergent shape with the upper face side (inner surface side of pipe 20) of band 10, the taper angle γ of this convergent shape is 25 °, and convergent height δ is 4mm (thickness 21%), and regulates rollforming, makes that the butt joint angle θ between the vertical edge of band opened 0.3 ° towards the tube outer surface side before being about to carry out resistance welded.
(embodiment of the invention 32)
As the embodiment of the invention 32, carry out resistance welded by this way, promptly, first stand of the finned blade forming stand by comprising two stands is configured as roughly straight convergent shape with the upper face side (inner surface side of pipe 20) of band 10, the taper angle γ of this convergent shape is 45 °, and convergent height δ is 7mm (thickness 37%), and second stand by this finned blade forming stand is configured as roughly straight convergent shape with the following side (the outer surface side of pipe 20) of band 10, the taper angle α of this convergent shape is 45 °, and convergent height β is 7mm (thickness 37%), and the adjusting rollforming makes that the butt joint angle θ between the vertical edge of band opened 0.2 ° towards the pipe internal surface side before being about to carry out resistance welded.
(comparative example 31)
Embodiment 31 as a comparison, carry out resistance welded by this way, promptly, first stand of the finned blade forming by comprising three stands is configured as roughly straight convergent shape with the following side (the outer surface side of pipe 20) of band 10, the taper angle α of this convergent shape is 20 °, and convergent height β is 3mm (thickness 16%), and the upper face side of band 10 (inner surface side of pipe 20) is configured as roughly straight convergent shape by first stand, the taper angle γ of this convergent shape is 20 °, and convergent height δ is 3mm (thickness 16%), and the adjusting rollforming makes that the butt joint angle θ between the vertical edge of band opened 1.1 ° towards the tube outer surface side before being about to carry out resistance welded.
(prior art embodiment 31)
As prior art 31, carry out resistance welded by this way, that is, as shown in figure 10, each strip edge is roughly rectangular, and the butt joint corner θ between the vertical edge of band opened 1.1 ° towards the tube outer surface side before being about to carry out resistance welded.
Measurement is according to the Charpy impact value and the brittle fracture Surface factor of the welding portion of the electrical resistance welding tube of above manufacturing, and the result of measurement is shown in the table 3.
Table 3
| Form the method for convergent shape | Convergent shape before being about to resistance welded | Butt joint corner between the vertical edge of band | The Charpy impact value | The brittle fracture Surface factor | ||
| The embodiment of the invention 31 | The 3rd stand of three stand finned blade formings | Taper angle: 25 ° of convergent form height degree: 4mm (thickness 21%) | Towards 0.3 ° of tube outer | 250J | 12％ | |
| The embodiment of the invention 32 | First stand of two stand finned blade formings and second stand | Taper angle: 45 ° of convergent form height degree: 7mm (thickness 37%) | Towards 0.2 ° of pipe internal surface side | 310J | 8％ | |
| The comparative example 31 | First stand of three stand finned blade formings | Taper angle: 20 ° of convergent form height degree: 3mm (thickness 16%) | Towards 1.1 ° of tube outer surface sides | 130J | 33％ | |
| Prior art embodiment 31 | Shapeless | No convergent shape | Towards 1.1 ° of tube outer surface sides | 25J | 55％ |
As known from Table 3, in the electrical resistance welding tube according to the embodiment of the invention 31 and 32, welding portion has high impact strength and little brittle fracture Surface factor, that is, toughness is splendid, and the reliability of products height.On the contrary, in comparative example 31 and prior art embodiment 31, welding portion has low impact strength and big brittle fracture Surface factor, that is, toughness reduces, and reliability of products is low.
Therefore, confirmed constructed in accordancely to have the electrical resistance welding tube of splendid weld seam characteristic.
Embodiment 4
Followingly be described according to embodiment.
Here, adopting width is that 1920mm, thickness are that to make diameter be the electrical resistance welding tube of 600mm for the band (steel band) of 19.1mm.
Downcut test pieces from the welding portion of the electrical resistance welding tube of having made, and this test pieces is carried out the performance of Charpy test with the assessment pipe.Do a Charpy test pieces sampling at each point in ten differences on the length of tube direction by this way, promptly, the longitudinal direction of test pieces is parallel to the pipe circumferencial direction, and the longitudinal center of recess is corresponding to the center of welding portion on thickness.Test pieces is configured as JIS52mm-V-recess shock-testing sheet, and under-46 ℃, carries out shock-testing, and measure Charpy impact value and brittle fracture Surface factor.125J or above Charpy impact value and 35% or following brittle fracture Surface factor be appointed as the performance range of allowing respectively.
(embodiment of the invention 41)
As the embodiment of the invention 41, make electrical resistance welding tube according to embodiment.At this moment, carry out resistance welded by this way, promptly, the 3rd stand of the finned blade forming stand by comprising three stands is configured as roughly straight convergent shape with the following side (the outer surface side of pipe 20) of band 10, the taper angle α of this convergent shape is 25 °, and convergent height β is 4mm (thickness 21%), and regulates rollforming, makes that the V word angle φ by the edge shaping of band was 2.5 ° before being about to carry out resistance welded.
(embodiment of the invention 42)
As the embodiment of the invention 42, carry out resistance welded by this way, promptly, first stand of the finned blade forming stand by comprising two stands is configured as roughly straight convergent shape with the upper face side (inner surface side of pipe 20) of band 10, the taper angle γ of this convergent shape is 45 °, and convergent height δ is 7mm (thickness 37%), and second stand by this finned blade forming stand is configured as roughly straight convergent shape with the following side (the outer surface side of pipe 20) of band 10, the taper angle α of this convergent shape is 45 °, and convergent height β is 7mm (thickness 37%), and the adjusting rollforming, make that the V word angle φ by the edge shaping of band was 7.5 ° before being about to carry out resistance welded.
(comparative example 41)
Embodiment 41 as a comparison, carry out resistance welded by this way, promptly, first stand of the finned blade forming by comprising three stands is configured as roughly straight convergent shape with the following side (the outer surface side of pipe 20) of band 10, the taper angle α of this convergent shape is 20 °, and convergent height β is 3mm (thickness 16%), and the upper face side of band 10 (inner surface side of pipe 20) is configured as roughly straight convergent shape by first stand, the taper angle γ of this convergent shape is 20 °, and convergent height δ is 3mm (thickness 16%), and the adjusting rollforming, make that the V word angle φ by the edge shaping of band was 1.5 ° before being about to carry out resistance welded.
(prior art embodiment 41)
As prior art embodiment 41, carry out resistance welded by this way, that is, each strip edge and is regulated rollforming in the form of a substantially rectangular, makes that the V word angle φ that is shaped by strip edge was 1.8 ° before the resistance welded that is about to carry out as shown in figure 12.
Measurement is according to the Charpy impact value and the brittle fracture Surface factor of the welding portion of the electrical resistance welding tube of above manufacturing, and the result of measurement is shown in the table 4.
Table 4
| Form the method for convergent shape | Convergent shape before being about to resistance welded | V word angle | The Charpy impact value | The brittle fracture Surface factor | |
| The embodiment of the invention 41 | The 3rd stand of three stand finned blade formings | Taper angle: 25 ° of convergent form height degree: 4mm (thickness 21%) | 2.5° | |
12％ |
| The embodiment of the invention 42 | First stand of two stand finned blade formings and second stand | Taper angle: 45 ° of convergent form height degree: 7mm (thickness 37%) | 7.5° | |
8％ |
| The comparative example 41 | First stand of three stand finned blade formings | Taper angle: 20 ° of convergent form height degree: 3mm (thickness 16%) | 1.5° | 130J | 33％ |
| Prior art embodiment 41 | Shapeless | No convergent shape | 1.8° | 25J | 55％ |
As known from Table 4, in the electrical resistance welding tube according to the embodiment of the invention 41 and 42, welding portion has high impact strength and little brittle fracture Surface factor, that is, toughness is splendid, and the reliability of products height.On the contrary, in the electrical resistance welding tube according to comparative example 41 and prior art embodiment 41, welding portion has low impact strength and big brittle fracture Surface factor, that is, toughness reduces, and reliability of products is low.
Therefore, confirmed constructed in accordancely to have the electrical resistance welding tube of splendid weld seam characteristic.
Claims (9)
1. a manufacturing has the method for the electrical resistance welding tube of splendid weld seam characteristic, it is characterized in that:
Therein band is formed and makes edge butt joint and weld with in the process that forms pipe by resistance welded,
Before carrying out described resistance welded, be convergent shape with the edge shaping of the upper and lower surface side of the edge of any one face side in the upper face side of described band or the following side or described band.
2. a manufacturing has the method for the electrical resistance welding tube of splendid weld seam characteristic, it is characterized in that:
In the finned blade forming of roll forming process,
The fin shape that employing has two or more angles with described shape transferred thereon on strip edge, on described edge, to form convergent shape.
3. manufacturing according to claim 1 and 2 has the method for the electrical resistance welding tube of splendid weld seam characteristic, it is characterized in that:
The edge at a side place is circular on the thickness direction of described band.
4. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to each described manufacturing in the claim 1 to 3, it is characterized in that:
The edge at the internal side diameter place of described band is shaped as convergent shape in the previous stage of finned blade forming, and,
The edge at the outside diameter place of described band is shaped as convergent shape in the latter half of finned blade forming.
5. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to each described manufacturing in the claim 1 to 4, it is characterized in that:
In the finned blade forming that comprises fin end stand at least, be convergent shape with described edge shaping.
6. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to each described manufacturing in the claim 1 to 5, it is characterized in that:
After finned blade forming in the convergent shape of described band,
Spend in the scope of 50 degree 25 towards the angle of vertical direction from the surface of strip edge, and,
Length of perpendicular at a side place from the starting position that is shaped as convergent shape to end position is 20% to 45% of a thickness.
7. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to each described manufacturing in the claim 1 to 6, it is characterized in that:
When being blown into non-active gas or reducibility gas, carry out resistance welded.
8. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to each described manufacturing in the claim 1 to 7, it is characterized in that:
The butt joint angle between the sheet material edge for from-1 spend+carry out resistance welded under the situation of 1 degree.
9. have the method for the electrical resistance welding tube of splendid weld seam characteristic according to each described manufacturing in the claim 1 to 8, it is characterized in that:
Carry out resistance welded at the V word angle that is shaped by strip edge for spending under the situation of 8 degree from 2.
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| CN201310674189.8A CN103752643B (en) | 2005-12-16 | 2006-11-09 | Manufacture the method with the electrical resistance welding tube of splendid weld characteristic |
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| JP2005362722A JP4720480B2 (en) | 2005-12-16 | 2005-12-16 | Manufacturing method of electric resistance welded tube with good weld characteristics |
| JP362722/2005 | 2005-12-16 | ||
| JP163203/2006 | 2006-06-13 | ||
| JP186675/2006 | 2006-07-06 | ||
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| CN104607492A (en) * | 2015-01-19 | 2015-05-13 | 山东泰丰钢业有限公司 | Stable and parallel butt-joint technology for steel strip edges of automobile transmission shaft tubes |
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|---|---|---|---|---|
| US9109884B2 (en) | 2007-02-13 | 2015-08-18 | Jfe Steel Corporation | Method and equipment for manufacturing electric resistance welded steel pipe |
| JP5194728B2 (en) * | 2007-11-13 | 2013-05-08 | Ｊｆｅスチール株式会社 | ERW pipe manufacturing method with excellent weld properties |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5731485A (en) * | 1980-08-04 | 1982-02-19 | Nippon Steel Corp | X-shaped groove welding method for electro-unite tube manufacture |
| JPH02307686A (en) * | 1989-05-24 | 1990-12-20 | Kawasaki Steel Corp | Production of stainless electric welded steel tube |
| JPH04105709A (en) * | 1990-08-22 | 1992-04-07 | Kobe Steel Ltd | Manufacture of resistance welded tube |
| US5494209A (en) * | 1992-12-28 | 1996-02-27 | Olin Corporation | Method for the manufacture of an internally enhanced welded tubing |
| KR101169237B1 (en) * | 2005-12-16 | 2012-08-02 | 제이에프이 스틸 가부시키가이샤 | Method of manufacturing electric resistance welded tube with excellent weld characteristic |
-
2005
- 2005-12-16 JP JP2005362722A patent/JP4720480B2/en active Active
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2006
- 2006-11-09 CN CNA2006800407469A patent/CN101304823A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104607492A (en) * | 2015-01-19 | 2015-05-13 | 山东泰丰钢业有限公司 | Stable and parallel butt-joint technology for steel strip edges of automobile transmission shaft tubes |
| CN104607492B (en) * | 2015-01-19 | 2016-01-06 | 山东泰丰钢业有限公司 | A kind of vehicle transmission central siphon steel band edge stablizes parallel docking technique |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4720480B2 (en) | 2011-07-13 |
| JP2007160383A (en) | 2007-06-28 |
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