CN105960306B

CN105960306B - Multi-electrode single side buried arc welding method, the manufacturing method for welding object

Info

Publication number: CN105960306B
Application number: CN201480074735.7A
Authority: CN
Inventors: 铃木励; 铃木励一; 山崎圭; 幸村正晴; 村西良昌
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 2014-02-12
Filing date: 2014-10-03
Publication date: 2018-11-30
Anticipated expiration: 2034-10-03
Also published as: KR20160105900A; JP2015150572A; CN105960306A; WO2015122047A1

Abstract

First welding unit (10) of the welder (1) by using the first welding wire (110), the second welding unit (20) using the second welding wire (120) carry out single side submerged arc welding to steel plate using the third welding unit (30) of third welding wire (130), using the 4th welding unit (40) of the 4th welding wire (140).At this time, in the first welding unit (10), the feed speed of the first welding wire (110) is controlled as constant speed using the first feed arrangement (11), and the use of feeding classification is first source of welding current (12) that direct current and external behavior are set as constant-voltage characteristic, the first welding wire (110) is fed.The bad order of the root pass obtained in multi-electrode single side submerged arc welding is reduced as a result,.

Description

Multi-electrode single side buried arc welding method, the manufacturing method for welding object

Technical field

The present invention relates to the manufacturing methods of multi-electrode single side buried arc welding method, welding object.

Background technique

One kind as self-consuming electrode type arc-welding process, it is known to following submerged arc welding method：By by the metal of powdery, The solder flux of the compositions such as artificial oxidation's object or mineral is dispersed on the surface of the groove of steel plate, and on the slope for being piled up in steel plate Mouthful solder flux among, generate electric arc from electrode wire to the electrode wire circulating current that feeding comes, thus by electrode wire and Steel plate melting mixing and it is integrated.The submerged arc welding method and coating welding, TIG (tungsten inert gas) arc-welding process, gas The others arc-welding process such as body shielded arc welding connection are compared, and are had by using high current and fusion penetration is relatively deep, improves efficiency Such speciality.

Here, in patent document 1, recording following content：In submerged arc welding method, used as external behavior The source of welding current with droop characteristic or constant-current characteristics is fed to electrode wire, and according to weldingvoltage setting signal and The size of the signal of the difference of weldingvoltage feedback signal carrys out coordination electrode welding wire feeding speed.

In addition, recording following multi-electrode single side submerged arc welding method in patent document 2：It is arranged along groove more A electrode wire, and back lining materials are configured by the back side in steel plate, thus once advanced using multiple electrodes welding wire In welded from the surface side of steel plate to back side.The multi-electrode single side submerged arc welding method (can be claimed in primary traveling Once to run) in complete penetration construction is carried out to the whole thickness of steel plate, without overturning steel plate, therefore, in shipbuilding, bridge It is widely used in equal fields.

Citation

Patent document

Patent document 1：Japanese Unexamined Patent Publication 2000-117442 bulletin

Patent document 2：Japanese Unexamined Patent Publication 2007-268551 bulletin

Summary of the invention

Subject to be solved by the invention

In above-mentioned multi-electrode single side submerged arc welding, using it is in multiple electrodes welding wire, mainly it is most advanced to steel plate The electrode wire (first pole) of row welding forms root pass in the back side of steel plate.

However, using the source of welding current with droop characteristic or constant-current characteristics to carry out using the electrode wire to first pole Feed and based on arc voltage to feed speed carry out feedback control structure in the case where, sometimes acquisition root weld The case where bad order is generated in road.

It is an object of the present invention to reduce the bad order of the root pass obtained in multi-electrode single side submerged arc welding.

Solution

First pole and multi-electrode single side submerged-arc welding with the first extremely continuous subsequent pole have been used the present invention relates to a kind of Connect method, which is characterized in that the first pole and it is described it is subsequent extremely in, respectively using diameter be 2.4mm or more welding wire, The speed control of the feeding classification and external behavior and the feed speed of each welding wire of the power supply fed about each welding wire Mode processed, it is described formerly extremely in be set as, the feeding classification be direct current, the external behavior be constant-voltage characteristic, the speed Spend control mode be constant speed control, it is described it is subsequent extremely in be set as any one of following (a)~(e)：

(a) feeding classification is direct current, and the external behavior is constant-voltage characteristic, and the speed control method is constant speed Degree control；

(b) feeding classification is exchange, and the external behavior is constant-voltage characteristic, and the speed control method is constant speed Degree control；

(c) feeding classification is exchange, and the external behavior is constant-current characteristics, and the speed control method is based on electricity The Voltage Feedback of arc voltage controls；

(d) feeding classification is exchange, and the external behavior is droop characteristic, and the speed control method is based on electricity The Voltage Feedback of arc voltage controls；

(e) feeding classification is direct current, and the external behavior is constant-current characteristics, and the speed control method is based on electricity The Voltage Feedback of arc voltage controls.

Such multi-electrode single side buried arc welding method is characterized in that, the subsequent pole be configured to include with it is described formerly Extremely continuous multiple electrodes, the multiple electrode for constituting the subsequent pole respectively in, it is the feeding classification, described external special Property and the speed control method be set to any one of described (a) to described (e).

In addition, which is characterized in that it is in the multiple electrode for constituting the subsequent pole, from the first pole when Positioned at most rear side it is most ultimate in, the feeding classification, the external behavior and the speed control method are set to institute State (c) or described (d).

Furthermore, which is characterized in that using the power supply with the constant-voltage characteristic, at operating point Voltage relative to electric current gradient differential value dV/dI be -12.0 × 10^-3(V/A) more than.

In addition, which is characterized in that the case where using the power supply with the constant-current characteristics or the droop characteristic Under, as the voltage at operating point relative to the gradient of electric current differential value dV/dI be -24.0 × 10^-3(V/A) below.

In addition, according to other viewpoints, the present invention relates to one kind by using first pole and with this it is formerly extremely continuous after The manufacturing method for the welding object that the single side submerged arc welding of continuous pole is welded to base material, which is characterized in that described first Pole and it is described it is subsequent extremely in, respectively using diameter be 2.4mm or more welding wire, about the power supply fed to each welding wire Feeding classification and external behavior and the feed speed of each welding wire speed control method, it is described formerly extremely in setting For, the feeding classification is direct current, and the external behavior is constant-voltage characteristic, and the speed control method is constant speed control, It is described it is subsequent extremely in be set as any one of following (a)~(e)：

Invention effect

In accordance with the invention it is possible to reduce the bad order of the root pass obtained in multi-electrode single side submerged arc welding.

Detailed description of the invention

Fig. 1 is the figure for showing the Sketch of welder involved in the mode of implementation of the invention.

Fig. 2 is the knot for illustrating the first welding unit~respective source of welding current of the 4th welding unit and feed arrangement The figure of structure.

(a) of Fig. 3~(c) is the figure for illustrating the external behavior of the source of welding current.

Fig. 4 is the figure for illustrating the structure of the experimental provision in first embodiment and the first comparative example.

Fig. 5 is the figure for illustrating the structure of the experimental provision in second embodiment and the second comparative example.

Fig. 6 is the figure for illustrating the structure of the experimental provision in 3rd embodiment and third comparative example.

(a) of Fig. 7 is the figure for illustrating the size of each steel plate and groove in first embodiment and the first comparative example, (b) it is the figure for illustrating the size of each steel plate and groove in second embodiment and the second comparative example, is (c) to illustrate third reality Apply the figure of the size of each steel plate and groove in example and third comparative example.

Specific embodiment

Hereinafter, referring to attached drawing, detailed description of embodiments of the present invention.

Fig. 1 is the figure for showing the Sketch of welder 1 involved in present embodiment.The welder 1 uses four A electrode (welding wire) progress single side submerged arc welding (not shown) to the workpiece being made of steel plate (four electrode single side submerged arc weldings).

Welder 1 has the first welding unit 10 welded using the first welding wire 110, using the second welding wire 120 The second welding unit 20 for being welded, the third welding unit 30 welded using third welding wire 130 and use the 4th The 4th welding unit 40 that welding wire 140 is welded.In addition, welder 1, which has, carries the weldering of the first welding unit the 10~the 4th Order member 40 and the trolley 90 advanced along the moving direction A in right side towards left side from figure, the trolley driving for driving trolley 90 The control device of the movement of device 50 and control the 10~the 4th welding unit 40 of the first welding unit and trolley driving device 50 60.In addition, welder 1 has in internal receiving surface layer solder flux (not shown) and towards the of supply surface layer solder flux in lower section in figure One welding flux feeding device 70 and the second welding flux feeding device 80.It should be noted that in this embodiment, control device 60, first Welding flux feeding device 70 and the second welding flux feeding device 80 are also equipped on trolley 90.

Wherein, the first welding unit 10 has：First feed arrangement 11, has that top is downward along from figure Direction of the supply B and the first feed rolls 11a for feeding the first welding wire 110；And first source of welding current 12, the come with same feeding One welding wire 110 contacts and supplies the first ignition tip 12a connection of welding current (the first welding current).In addition, the first welding is single Member 10 is also equipped with：It winds the first welding wire 110 and becomes the reel (not shown) of the supply source of the first welding wire 110.

In addition, the second welding unit 20 has：Second feed arrangement 21, has that top is downward along from figure Direction of the supply B and the second feed rolls 21a for feeding the second welding wire 120；And second source of welding current 22, the come with same feeding Two welding wires 120 contact and supply the second ignition tip 22a connection of welding current (the second welding current).In addition, the second welding is single Member 20 is also equipped with：It winds the second welding wire 120 and becomes the reel (not shown) of the supply source of the second welding wire 120.

In addition, third welding unit 30 has：Third feed arrangement 31, has that top is downward along from figure Direction of the supply B and the third feed rolls 31a for feeding third welding wire 130；And the third source of welding current 32, the come with same feeding Three welding wires 130 contact and supply the third ignition tip 32a connection of welding current (third welding current).In addition, third welding is single Member 30 is also equipped with：It winds third welding wire 130 and becomes the reel (not shown) of the supply source of third welding wire 130.

In addition, the 4th welding unit 40 has：4th feed arrangement 41, has that top is downward along from figure Direction of the supply B and the 4th feed rolls 41a for feeding the 4th welding wire 140；And the 4th source of welding current 42, the come with same feeding Four welding wires 140 contact and supply the 4th ignition tip 42a connection of welding current (the 4th welding current).In addition, the 4th welding is single Member 40 is also equipped with：It winds the 4th welding wire 140 and becomes the reel (not shown) of the supply source of the 4th welding wire 140.

It should be noted that the welder 1 of present embodiment is configured to, first source of welding current is carried on trolley 90 12, second source of welding current 22, the third source of welding current 32 and the 4th source of welding current 42 make these first source of welding current 12~four The source of welding current 42 is advanced together with trolley 90, but not limited to this.For example, it is also possible to by these first sources of welding current 12~the 4th weldering It connects power supply 42 to be configured to be fixed on the outside of trolley 90, and uses cable etc. by the 12~the 4th source of welding current 42 of first source of welding current It is connected with each component on trolley 90.

In addition, the first welding flux feeding device 70 has will be contained in that internal surface layer solder flux supplies towards lower section in figure the One solder flux supply mouth 70a.Moreover, the supply amount of the surface layer solder flux of the first welding flux feeding device 70 is supplied by being set to the first solder flux The valve (not shown) of device 70 adjusts.

In addition, the second welding flux feeding device 80 has will be contained in that internal surface layer solder flux supplies towards lower section in figure the Two solder flux supply mouth 80a.Moreover, the supply amount of the surface layer solder flux of the second welding flux feeding device 80 is supplied by being set to the second solder flux The valve (not shown) of device 80 adjusts.

In the welder 1, from moving direction A, first as first electrode is configured in most downstream side Welding wire 110 is being configured with the second welding wire 120 as second electrode than the first welding wire 110, than the second welding wire on the upstream side 120 on the upstream side configured with the third welding wire 130 as third electrode, on the upstream side and be most upper than third welding wire 130 It swims side and is configured with the 4th welding wire 140 for becoming the 4th electrode.In addition, in the welder 1, the first welding flux feeding device 70 Configuration is than the position of 110 downstream of the first welding wire, the second welding flux feeding device 80 is configured from shifting from moving direction A from Dynamic direction A observation is than the second welding wire 120 on the upstream side and than the position of 130 downstream of third welding wire.Moreover, from figure When side's observation welder 1, the first solder flux supply mouth 70a, the first welding wire 110, the second welding wire 120, the second solder flux supply mouth 80a, third welding wire 130 and the 4th welding wire 140 are successively along the arranged in a straight line of moving direction A.

In addition, as the 110~the 4th welding wire 140 of the first welding wire, the use of respective diameter being 2.4mm in the welder 1 Above and 6.4mm welding wire below.Here, can be the diameter of four welding wires about the 110~the 4th welding wire 140 of the first welding wire All identical, the diameter that can be three welding wires is identical and the diameter of a welding wire is different, can be the diameter phase of two welding wires With and the diameter of other two welding wire is different, can also be that the diameter of four welding wires is different.

In addition, the 110~the 4th welding wire 140 of first welding wire is not respectively by having substantially used in the welder 1 The solid welding wire of solder flux is constituted.But it is also possible to constitute more than one in above-mentioned welding wire by the welding wire of filling flux.

It should be noted that in the following description, the first welding unit 10 comprising the first welding wire 110 is known as sometimes " first pole ".In addition, the second welding unit 20 comprising the second welding wire 120, the third comprising third welding wire 130 are welded sometimes Unit 30 and the 4th welding unit 40 comprising the 4th welding wire 140 are referred to as " subsequent pole ".In addition, the second weldering will be included sometimes Second welding unit 20 of silk 120 is known as " the first dynode ", and the third welding unit 30 comprising third welding wire 130 is known as " the second dynode ", by the 4th welding unit 40 " most ultimate " comprising the 4th welding wire 140.

Fig. 2 is the respective welding of the first the 10~the 4th welding unit of welding unit 40 for illustrating to constitute welder 1 Power supply (the 12~the 4th source of welding current 42 of first source of welding current) and feed arrangement (the 11~the 4th feed arrangement of the first feed arrangement 41) figure of structure.Here, Fig. 2 shows feeding classifications and external behavior, each feeding in each welding unit, each source of welding current The relationship between wire speed control mode in device.

Firstly, being illustrated to the first welding unit 10.

First source of welding current 12 for constituting the first welding unit 10 is to use DC (Direct as feeding classification Current DC power supply), external behavior are constant-voltage characteristic.In addition, as wire speed control mode, the first feeding dress Set the fixed speed control that 11 progress feed the first welding wire 110 with constant speed.

Then, the second welding unit 20 is illustrated.In the present embodiment, the second welding unit 20 is by following explanation Any one of five combinations (first structure~the 5th structure) constitute.

(a) first structure

Second source of welding current 22 in first structure is to use that DC's (Direct Current) is straight as feeding classification Galvanic electricity source, external behavior are constant-voltage characteristic.In addition, the second feeding dress as wire speed control mode, in first structure Set the fixed speed control that 21 progress feed the second welding wire 120 with constant speed.In this way, first structure becomes and the first welding unit 10 Identical combination.

(b) the second structure

Second source of welding current 22 in second structure is the AC power source that AC is used as feeding classification, external behavior For constant-voltage characteristic.In addition, the second feed arrangement 21 in the second structure is carried out with constant speed as wire speed control mode Feed the fixed speed control of the second welding wire 120.

(c) third structure

Second source of welding current 22 in third structure is the AC power source that AC is used as feeding classification, external behavior For constant-current characteristics.In addition, the second feed arrangement 21 in third structure is carried out by based on electricity as wire speed control mode The feedback control of arc voltage and gradually with speed appropriate feed the second welding wire 120 voltage FB (Feed Back) speed Control.

(d) the 4th structure

Second source of welding current 22 in 4th structure is the AC power source that AC is used as feeding classification, external behavior For droop characteristic.In addition, the second feed arrangement 21 in the 4th structure is carried out by based on electricity as wire speed control mode The feedback control of arc voltage and gradually with speed appropriate feed the second welding wire 120 voltage FB speed Control.

(e) the 5th structure

Second source of welding current 22 in 5th structure is the DC power supply that DC is used as feeding classification, external behavior For constant-current characteristics.In addition, the second feed arrangement 21 in the 5th structure is carried out by based on electricity as wire speed control mode The feedback control of arc voltage and gradually with speed appropriate feed the second welding wire 120 voltage FB speed Control.

In addition, third welding unit 30 and the 4th welding unit 40 are identical as the second welding unit 20, it can be by above-mentioned Any one of first structure (a)~the 5th structure (e) constitute.Here, the second welding unit 20, third welding unit 30 with And the 4th welding unit 40 can use the identical structure of three wholes, can also using two identical and a different knot Structure, the structure that three wholes can also be used different.

It should be noted that the feed speed of the 110~the 4th welding wire 140 of the first welding wire can be based on trolley 90 towards movement side It is determined to the speed (speed of welding) of A movement.Such as in the case where fixed speed control, operator is determined based on speed of welding The a reference value of feed speed, and fixed speed control is carried out in a manner of a reference value for maintaining the feed speed.In addition, for example in voltage In the case where FB speed Control, operator determines a reference value of feed speed on the basis of speed of welding, relative to feeding speed The a reference value of degree carries out speed Control to feed back arc voltage.

Then, the external behavior of above-mentioned each source of welding current is illustrated.

Fig. 3 is the figure for illustrating the external behavior of the source of welding current.Here, Fig. 3 (a) exemplifies constant-voltage characteristic, Fig. 3 (b) Constant-current characteristics is exemplified, Fig. 3 (c) exemplifies droop characteristic.In addition, horizontal axis is output electric current I in Fig. 3 (a)~(c) is respective (A), the longitudinal axis is output voltage V (V).External characteristic curve is moved according to the instruction of the current or voltage inputted to the source of welding current (variation).Fig. 3 (a) exemplifies external characteristic curve corresponding with the instructed voltage of four-stage, and Fig. 3 (b)~(c) is illustrated External characteristic curve corresponding with the indicator current of four-stage out.It should be noted that in the case where the source of welding current, output Electric current I corresponds to welding current, and output voltage V corresponds to arc voltage will be because (consuming in cable, connecing with other voltage loss Point resistance etc.) be added obtained from aggregate value.

Firstly, being illustrated to constant-voltage characteristic shown in Fig. 3 (a).

In the case where constant-voltage characteristic, relative to the variation of output electric current I, the variation of output voltage V becomes smaller.

Then, constant-current characteristics shown in Fig. 3 (b) is illustrated.

In the case where constant-current characteristics, relative to the variation of output electric current I, the variation of output voltage V becomes larger.From opposite From the point of view of viewpoint, it is believed that under constant-current characteristics, even if output voltage V is dramatically changed, the variation for exporting electric current I is also smaller.

Then, droop characteristic shown in Fig. 3 (c) is illustrated.

In the case where droop characteristic, with constant-current characteristics the case where is identical, relative to the variation of output electric current I, output electricity The variation of pressure V becomes larger.But with the constant-current characteristics the case where compared with, in the case where droop characteristic, the variation of output voltage V is slow With, and changed according to current value.

Here, Fig. 3 (a)~(c) is while showing respective external behavior, it is also shown that for generating the electric arc of arc length L Arc characteristic.In each figure, the intersection point of the curve of the curve and arc characteristic of the external behavior of any one, which becomes, generates work For the purpose of arc length L electric arc operating point P (specific output electric current I and specific output corresponding with the output electric current I Voltage V).It should be noted that in the following description, in the operating point P that will be used to generate the electric arc of arc length L as a purpose , voltage relative to the gradient of electric current be known as differential value dV/dI.

Here, the variation of the depth of fusion with droop characteristic, the source of welding current of constant-current characteristics is less, in submerged arc welding It is preferred.But due in the source of welding current with droop characteristic, constant-current characteristics arc voltage be easy to happen variation, because This, the usually feeding with the welding wire under voltage FB speed Control is combined.In the welding that will have droop characteristic, constant-current characteristics In the case that power supply is combined with voltage FB speed Control, if arc length L shortens, welding wire is reduced according to the decline of arc voltage Feed speed, to make arc length L restore the original length, on the other hand, if arc length L is elongated, according to the rising of arc voltage And the feed speed of welding wire is improved, so that arc length L be made to restore the original length.

On the other hand, the source of welding current with constant-voltage characteristic is excellent in the MAG welding or MIG welding using thin footpath welding wire Choosing.In addition, the source of welding current with constant-voltage characteristic is also used for the submerged-arc welding using diameter for 2.0mm welding wire below sometimes It connects.But due in the source of welding current with constant-voltage characteristic welding current be easy to happen variation, usually with constant speed control The feeding of welding wire under system is combined.In the case where that will have the source of welding current of constant-voltage characteristic to combine with fixed speed control, if Arc length L shortens, then being become larger automatically by welding current makes arc length L restore the original length, on the other hand, if arc length is elongated, Then being become smaller automatically by welding current makes arc length L restore the original length.

Here, being illustrated to the feature of the welding condition in the multi-electrode single side buried arc welding method of present embodiment.

Diameter > of the < about each welding wire

In single side submerged arc welding method, need that groove is made to melt and form root pass with stronger arc force.But and Non- is only that the higher the better for welding current, when making wire melting obtain more with high speed feed, will form melt immediately below electric arc It is detained, the arc force of itself is buffered, and causes to reduce fusion penetration.Therefore, it is desirable to increase welding current and welding wire melting amount not Increase, in order to cope with the condition, preferably with current density (A/mm²) lower condition, i.e. thickening gage of wire and with low Speed feeding welding wire.It is the welding wire of 1.6mm thin footpath below usually using diameter, but as list in gas protective arc welding Face submerged arc welding with and it is preferred that the welding wire that diameter is 2.4mm or more.The more desirable welding wire for the use of diameter being 3.2mm or more, into one The welding wire that step expectation is 4.8mm or more using diameter.Although being not provided with the technical restriction of the upper limit, from the feeding of welding wire, Cuttability sets out, and diameter is that 6.4mm or less is more practical.

Quantity > of the < about electrode

It is formerly great to play the role of melting groove relatively to form molten bath and root pass deeply, since welding condition is special It infuses in the effect, therefore in the case that and molten bath relatively thin in the plate thickness of base material reaches the surface of base material, also can not using single electrode Surface layer welding bead appearance is set to become good.In this regard, the most ultimate effect for primarily serving the appearance for smooth surface layer welding bead, therefore, It is formed and formerly extremely different welding conditions.In this way, needing to carry out effect distribution in single side submerged arc welding, therefore, it is necessary to real Now use the multi-electrode of two or more welding wires.In general, the quantity of welding wire increases as the plate thickness of steel plate thickens.Although not yet There is the technical restriction to the quantity setting upper limit of electrode, but is used as single-sided welding, such as four electrode shown in FIG. 1 can be used System.

Appropriate interval is provided between each electrode.According to plate thickness, speed of welding, used bonding machine, welding wire Feeding various controls difference and cannot treat different things as the same, can suitably be adjusted.It should be noted that there is also to electrode Between the case where supply mouth (shown in FIG. 1 first solder flux supply mouth 70a, the second solder flux supply mouth 80a) of solder flux is set.

< about formerly extremely in wire speed control mode, external behavior and feeding classification >

[about formerly extremely in wire speed control mode]

In multi-electrode single side submerged arc welding, first pole is primarily used to form root pass.The inventors discovered that in root In welding, the driving force of fusion penetration significantly affects root quality, is easy to cause the excessive or root of root pass insufficient.Moreover, Experiment is repeated for the driving force of fusion penetration in the present inventor, sends out seam usual, is with electric current and factors of voltage Standard, however it is really not so in single-sided welding, and the disturbance degree of the feed speed of welding wire is maximum.

That is, welding wire is easy to be pressed by the molten bath of surface tension body abutment to steel plate if the feed speed of welding wire is excessive The back side forms excessive root.In addition, welding wire can also break through molten bath sometimes if feed speed is fast.

On the contrary, molten bath will not be pushed from the steel plate back side and become root deficiency if the feed speed of welding wire is insufficient.? Theoretically, if the feed speed of welding wire without time loss can be made relative to the variation for the arc length L being inevitably generated It reacts out, so that arc length L is restored original state, then should be unable to generate these phenomenons.However, the welding wire horse of practical upper feeding welding wire Up to being industrial products, delay to a certain degree is generated in reaction.Relative to the delay in the reaction time, the height of root pass Without firm property, it is easy to be influenced by its variation.

Be clear that in view of the problem, to formed root weld impact formerly extremely in, even if it is expected that carry out electricity Stream, voltage, which change, will not impact feed speed and feed speed is made to become constant control (fixed speed control). For current particle size submerged arc welding, welding wire feeding constant control is previous inappropriate control methods.It is managed By being, the entire profile of particle size welding wire is difficult to equably melt, as a result, welding wire melting speed becomes unstable, in turn Also it can not expect the stabilisation of arc length L.However, in the case where forming root pass only in single-sided welding, compared with arc length L's It stabilizes, it is higher that feed speed stabilizes brought dimensionally stable effect.

[about formerly extremely in external behavior]

Then, as the prior art, the external behavior of first pole typically refers to droop characteristic.As described above, droop characteristic In, relative to voltage value variation and the variation of current value is small.As simple structure and cheap, the easy welding mechanism of maintenance It makes, it is previous using the movable bonding machine of iron core for utilizing leakage reactance without using electronic component, but in this approach, there is also only make Make historical background as droop characteristic.

In the application of non-root weld for causing biggest impact to fusion penetration depth for current value, current value is stablized to molten It is deep stabilize for be it is effective, on the other hand, root pass in root weld it is dimensionally stable in, the change of current value Dynamic and non-staple influence factor.On the other hand, although arc length L is compared with the variation of feed speed, to the stabilized shadow in root It rings less, however also brings adverse effect in the case where arc length L exceedingly change dramatically.Such as when arc length L is zero, i.e. electric arc When disappearance, welds itself and stop, or electric arc generates explosively in the starting the arc again, therefore, under this force can not It is normally formed root pass.On the other hand, it when arc length L is excessive, is still unable to maintain that electric arc and electric arc is made to disappear quickly, or The arc force of person's per unit area weakens, so that root pass can not be formed.

In addition, such lack is cut in the out-of-flatness of generation weld bead shape, the root for wriggling, excavating base material influenced by magnetic blow-out It falls into.That is, it needs to carry out the Stabilization Control of arc length L.

When in order to realize that root stabilizes and when premised on feed speed is constant, as making the stabilized method of arc length L, Need the control object other than feed speed control.It has been known that there is the melting speed of self-consuming electrode type welding welding wire to be indicated by formula (1), Give become square current value (welding current I) the maximum enlightenment of disturbance degree.

Mw=K1I+K2I²·ρ·L…(1)

Mw：Welding wire melts speed

I：Welding current

ρ：Resistivity

L：Welding wire protrudes length

K1,K2：Constant

Make the stabilized method of arc length L as premised on feed speed is constant as a result, makes welding current I energetically Variation is effective.For example, melting welding wire under speed Mw if arc length L shortens Drop, arc length L restore original state.On the other hand, if arc length L is elongated, welding wire melting speed is made and declining electric current sharply It spends Mw to rise, arc length L still restores original state.The phenomenon is commonly known as itself control action of arc length.Arc length itself Control action needs the rapidly variation of electric current, realizes that the external behavior of itself control action is only constant-voltage characteristic.Therefore, in order to Realize that the welding wire feeding speed needed for stabilizing root weld is constant, as indirect factor, need to make with it is first extremely corresponding The source of welding current external behavior be constant-voltage characteristic.

Such " wire speed control：Constant speed " and " external behavior：The combination of constant-voltage characteristic " is being using diameter It is used in the gas protective arc welding method of 1.6mm thin welding wire below.This is because meltbility is excellent due to welding wire is compared with thin, Therefore, itself control action of arc length becomes highly effective.However, the welding wire for being 2.4mm or more for diameter, and thinner than its Welding wire is compared, and meltbility is poor, therefore, when being used for non-single-sided welding, itself control action of arc length can not be made to play well Effect, causes electric arc and weld bead shape unstable.

[about formerly extremely in feeding classification]

Then, the feeding classification about first pole, it is single fillet welded formerly extremely in be necessary for direct current.It, must in exchange It is the state that zero, i.e. electric arc disappears that fixed cycle, which generates electric current,.For the subsequent pole in non-single-sided welding or single-sided welding i.e. After two electrodes, the influence that the electric arc of short time disappears to welding quality is little, but for first pole, to the stabilisation of root Stronger influence is caused, the principal element of destabilization is become.If electric arc not press by the promptly starting the arc again, the welding wire of solid Lower molten bath, becomes root transient state.

For above such reason, first pole is using " wire speed control：Constant speed ", " external behavior：Constant-voltage characteristic " And " feeding classification：The combination of direct current ".

It should be noted that most popular high current submerged arc welding machine is the AC machine of cheap iron core operating type at present. In this approach, external behavior necessarily becomes droop characteristic.In contrast, if using Thyristor in order to generate direct current, The direct current of high current can be then obtained, and external behavior also becomes constant-voltage characteristic.In addition, recently, for To Be Protected from Heat and it is defeated to be difficult to The converter type bonding machine of high current out, also develops the equipment using High-current output as speciality, if using the equipment, it can Obtain very excellent DC characteristic.

Wire speed control mode, external behavior and feeding classification > of the < about subsequent pole

Although visual confirmation can not be carried out in multi-electrode single side submerged arc welding, in the surface layer solder flux being piled up on steel plate The molten bath of middle formation is the long but also big liquid not only for being referred to as single pond made of the molten metal of essentially all of welding wire is connected Metal.As described above, extremely formerly there is maximum disturbance degree to the shape of root pass, if single pond, although disturbance degree phase To reduction, but subsequent pole still impacts the shape of root pass.Even if for example, utilizing first electricity for becoming first pole Pole forms the root pass of the liquid condition of excellent in shape, if but by first after second electrode by becoming subsequent pole The molten bath that a electrode is formed is acted in the way of to back side, then the root pass of final curdled appearance becomes out-of-flatness. Therefore, after second electrode, also with formerly extremely identical application " wire speed control：Constant speed " and " external behavior：It is permanent Press characteristic ".Here, with formerly extremely identical it is expected direct current, but the polar influence that second electrode is later as feeding classification Degree is opposite relative to first electrode to become smaller, accordingly it is also possible to using exchange.

On the other hand, when the plate thickness of steel plate thickens and number of electrodes also increases, even single pond or by subsequent pole shape At the pressure in molten bath slightly change, the back side in the farther away molten bath that will not adjust the distance causes large effect.In this feelings It, also can be using " the wire speed control used in the past under condition：Voltage FB speed Control " and " external behavior：Sagging spy Property ".Instead of droop characteristic, the identical " external behavior of destination properties is used：The source of welding current of constant-current characteristics " is not it is also apparent that ask Topic.Effect as subsequent pole, it is also desirable to the shape of smooth surface layer welding bead.For this purpose, even if feed speed occurs sometimes Variation, it is also effective for stabilizing current value, arc length L preferentially.For this requirement, it is preferred to use " wire speed control：Electricity Pressure FB speed Control ", " external behavior：Droop characteristic or constant-current characteristics " and be difficult to cause to interfere because of electric arc, magnetic blow-out is drawn " the feeding classification of the deviation risen：The combination of exchange ".

Other > of <

[about backing plate]

In single-sided welding, usually using the copper for the trough of belt for catching root pass or the backing plate material of soild oxide Material.It should be noted that soild oxide specifically refers to ceramic system or glass.It is usually used to be incorporated into the case where glass The banded structure of glass fibre.If, when excessive arc force acts on bonding layer, falling molten bath without backing material, electricity Arc disappears and leads to not continue to weld.If this worst situation can be prevented using arbitrary backing material.

If the steel plate bottom surface for becoming base material is in close contact, even if arc force is unstable, the shape of root pass also should It stabilizes, but actually biggish steel plate and out-of-flatness, it is slight curving in most cases or ripple occurs, it therefore, must can not It is in close contact.In this regard, in order to fill the gap between the steel plate bottom surface being inevitably generated and backing material, sometimes also in advance Spread backing plate solder flux.Then, falling for the molten bath of back side can be prevented in a way.Furthermore, it may have following method： Backing material is not laid, but injects gas by spreading backing plate solder flux thicker, and to the air hose laid thereunder Body lifts backing plate solder flux, to improve close contact.In this case, molten bath is fallen in order to prevent, and backing plate solder flux is sometimes Also using the powder lit-par-lit structure being laminated with curable resin.

[about surface layer solder flux]

Due to being the basic structure of bottom line as submerged arc welding, there is no need to illustrate, by solder flux be put by Referred to as container (shown in FIG. 1 first welding flux feeding device 70, second welding flux feeding device 80) of the lower section of hopper with hose, It is carried out along with welding, solder flux is from the front of first pole or further as needed from the hose front end being set between electrode Solder flux supply mouth spread with constant speed.

[about groove packing material]

When spreading powdered steel or steel alloy in groove in advance, melting occurs in welding and forms molten metal A part.Other than having the effect of improving efficiency, in the case where root gap is locally excessive, it is not easy to keep root de- It falls.In addition, also having the effect of the cooling velocity increased near weld part and inhibiting the quality deterioration in base material heat influence portion.Separately Outside, in root weld, has the effect of the unstable mitigation of welding wire feeding, electric arc for the subsequent pole for keeping first electrode later. But can not be completely melt when dispersion volume is excessive sometimes, to remain solid and cause defect, therefore, should not carry out The distribution of degree.Optimised quantity is determined using the balance of electric current, bevel shape.As the material of powder, so-called fine size is used Iron powder or by thin footpath welding welding wire cutting and formed coarse substance.

[differential value about the weldingvoltage with constant-voltage characteristic]

In general, specification is recorded with title as constant-voltage characteristic, droop characteristic, constant-current characteristics in bonding machine, therefore, Its characteristic of the less detailed survey in user side.However, the title of these external behaviors is conceptual content, and determine without quantitative Justice.Recently the machine of external behavior can be adjusted by having also appeared user.It is expected as the constant-voltage characteristic in operating point electric current Voltage-current characteristic gradient, i.e. differential value dV/dI and -12.0 × 10^-3(V/A) compared to as horizontal side.In other words, Desired differential value dV/dI is -12.0 × 10^-3(V/A) more than.If differential value dV/dI is -12.0 × 10^-3(V/A) more than, then Variation with arc length L accordingly varies widely electric current, effectively plays itself control action of arc length L, is therefore preferred. More preferably, if differential value dV/dI is -8.0 × 10^-3(V/A) more than, then root shape becomes more stable.It should be noted that General aspects as the external behavior comprising constant-voltage characteristic, it is impossible to which, as the gradient of+side, therefore, differential value dV/dI is 0 becomes the actual upper limit.

[about the differential value with constant-current characteristics or the weldingvoltage of droop characteristic]

Constant-current characteristics and droop characteristic not have quantitative definition.Constant-current characteristics and droop characteristic alternatively make The aspect difference that iron core operates generated leakage magnetic flux is generated or is utilized with rectifier cell, even if but occurring in arc length L It is identical that on this point electric current is constant is also directed toward in variation.Constant-current characteristics and droop characteristic preferred voltage-current characteristic jointly Gradient, the differential value dV/dI and -24.0 × 10 i.e. in operating point electric current^-3(V/A) comparing becomes vertical side, in other words, excellent The differential value dV/dI of choosing is -24.0 × 10^-3(V/A) below.If being -24.0 × 10 by differential value dV/dI^-3(V/A) below The Voltage Feedback control combination of characteristic and feed speed then can sensitively capture the variation of arc voltage, can by make into The stabilisation of arc length L is realized to velocity variations, to facilitate the stabilisation of surface layer weld bead shape.It should be noted that making For the general aspects comprising constant-current characteristics and the external behavior of droop characteristic, it is impossible to as the gradient of+side, therefore-∞ (nothing Limit is big) come true on lower limit.

Embodiment

Hereinafter, based on embodiment, the present invention is described in more detail.But the present invention is in the range for being no more than its purport It is interior, however it is not limited to embodiment below.

(first embodiment and the first comparative example)

Fig. 4 is the figure for illustrating the structure of the experimental provision in first embodiment and the first comparative example.It needs to illustrate , the basic structure of experimental provision shown in Fig. 4 and welder 1 shown in FIG. 1 share.Here, in Fig. 4 with experimental provision It also shows together together：Workpiece 200 comprising the first steel plate 201 and the second steel plate 202, to the surface side of workpiece 200 supply Surface layer solder flux 300, configuration the back side of workpiece 200 backing plate portion 400 and be formed in along with welding workpiece 200 Welding metal 500.

In addition, Fig. 7 (a) shows the size of each steel plate and groove in first embodiment and the first comparative example.At this In example, plate thickness 35mm, width 500mm × length 3000mm stretching are used as the first steel plate 201 and the second steel plate 202 The carbon steel sheet that intensity is 490Mpa grades carries out groove end face processing respectively, becomes banjo fixing butt jointing.Bevel shape is played from surface Become 45 ° of V-types at 29mm, remaining plate thickness 6mm is vertically root face.Root gap becomes the contact of two sides steel plate in most short part 0mm, but due to the deformation of steel plate, inevitably there is the position in the gap for generating maximum 2mm.Each welding wire (the first welding wire 110 ~the four welding wire 140) using the corresponding product of JIS Z3351 YS-S6, surface layer solder flux 300 uses JIS Z3352 SACI1's Corresponding product.Surface layer solder flux 300 is in the forward position of than first electrode (first pole) and second electrode and third electricity It is automatically continuously spread between pole appropriate.

In divided edge of steel plate back side, as backing plate portion 400 by being pressed with the backing plate for having spread the trough of belt of a small amount of backing plate solder flux 401 Copper sheet 402.In addition, between corresponding ignition tip and steel plate, wiring has the independent source of welding current about each electrode.It needs It is noted that the feed rolls that each welding wire is arranged on the surface of each ignition tip are sent to weld part.

Then, using experimental provision shown in Fig. 4, the test of four electrode single side buried arc welding methods has been carried out.More specifically For, using experimental rig shown in Fig. 4, gage of wire, feeding classification, external behavior, welding wire speed are made as unit of electrode Degree control, welding current, arc voltage change, to confirm its influence.In experimental provision shown in Fig. 4, the first weldering The interpolar distance of the front end of the front end and the second welding wire 120 of silk 110 is 40mm, the front end of the second welding wire 120 and third welding wire 130 The interpolar distance of front end be 120mm, the interpolar distance of the front end of the front end of third welding wire 130 and the 4th welding wire 140 is 30mm. Moreover, the speed of welding in this is 44 (cm/min).

In addition, having rated root pass shape, surface layer weld bead shape, internal flaw as test result.Root pass shape Shape more than width 10mm, the following are ideal forms by root height 2mm or more and 6mm, and small, width the deviation that will wriggle is few The case where be set as very good and be set as A, by above-mentioned evaluation elementary errors but without be modified the case where be set as B, will be welded due to root Road shape bad and need the case where being modified to be set as C and handle to be unqualified.About surface layer weld bead shape, using with root The identical evaluation criteria of portion's weld bead shape.About internal flaw, even if ultrasonic test, the cutting examination of section macroscopic view will be carried out It tests the case where being also set as "None" without the case where discovery defect, will confirm that out lack of fusion and is set as " having ".

Table 1 and table 2 show first embodiment and manufacturing condition and test result in the first comparative example.Here, table 1 Shown in No.1-1~No.1-5 be first embodiment, No.1-6~No.1-11 shown in table 2 is the first comparative example.

It should be noted that " AC " refers to exchange in the feeding classification shown in table 1 and table 2, " DC (EP) " refers to directly Stream and " the Electrode Plus " that welding wire, that is, electrode side is set as to anode, " DC (EN) " refer to direct current and by welding wire i.e. electrode sides It is set as " the Electrode Negative " of cathode.It is also identical in aftermentioned 3~table of table 6 about the representation.

[table 1]

[table 2]

Firstly, being illustrated to first embodiment.

No.1-1 uses direct current, constant-voltage characteristic, fixed speed control to first electrode, uses always after second electrode Since exchange, droop characteristic, voltage FB speed Control, obtain good root pass shape.On the other hand, by will be at It is set as exchange, droop characteristic, voltage FB speed Control for the 4th electrode in final path, surface layer weld bead shape also becomes very It is good.

No.1-2 be the external behavior relative to No.1-1 and in the source of welding current of first electrode differential value dV/dI compared with It is small, weaken the case where constant-voltage characteristic, be accompanied by this, itself control action of the arc length in the bonding layer welding of first electrode It dies down and becomes unstable, therefore, root pass shape ratio No.1-1 is slightly worse.That is, due to using direct current, constant speed control System, therefore obtain the root pass shape for becoming allowed band.

No.1-3 is similar with No.1-1, but the electric power polarity of first electrode is set as straight polarity, i.e. electrode side- (negative).In general, the electric power polarity under direct current mostly uses greatly direct current reversed polarity, i.e. electrode side+(just), but there is no ask welding quality Topic, in this construction method, shows and is able to use any method.

Whole electrodes are set as direct current, constant-voltage characteristic, fixed speed control by No.1-4, and second electrode has also been introduced later The control for reducing the pressure change in molten bath, thus obtains extraordinary root pass shape.However, on the other hand, using table In the case that layer weld bead shape is easy by interference, the direct current that is influenced of magnetic blow-out between electric arc, although within the allowable range, and adopting It is compared with the case where exchange slightly worse.

Whole electrodes are set as constant-voltage characteristic, fixed speed control by No.1-5, and only first electrode uses direct current, other electrodes are adopted With exchange.By the way that subsequent pole side, using exchanging, electric arc is not easily susceptible to magnetic blow-out influence, as a result, root pass shape and table Layer weld bead shape is very good.

Then, the first comparative example is illustrated.

No.1-6 is typical example used at present.Whole electrodes use exchange, droop characteristic, voltage FB speed Control. The variation of feed speed leads to the unstable of root molten bath with distinctive periodic electric arc disappearance is exchanged, although internal flaw, Special problem is not present in surface layer weld bead shape, but for root weld be it is unsuitable, root pass shape It is bad significant.

No.1-7 relative to No.1-6 and to the 4th application of electrode constant-voltage characteristic, fixed speed control, even if but only at The control for reducing the pressure change in molten bath is applied with for the 4th most ultimate electrode, also than first electrode is low for contribution rate, because This, is not carried out the improvement of root pass shape.

No.1-8 is similar with No.1-7, but not the 4th electrode but to second application of electrode constant-voltage characteristic, perseverance Speed control.But in second electrode for becoming the first dynode, compared with first electrode, to formation root pass The stabilisation contribution rate for the pressure that molten bath applies is lower, there is no the improvement of root pass shape.

In No.1-9, first electrode, second electrode directly adopt previous exchange, the welding of droop characteristic electricity Welding wire feeding is set as fixed speed control by source.In droop characteristic, in principle arc length stabilize must by welding wire feeding control Lai It realizes, but due to being constant speed, arc length static stabilization is absolutely not played.Therefore, arc length changes larger always, can not Realize stable welding.As a result, root pass shape and surface layer weld bead shape are more coarse and unstable, it is internal Generate lack of fusion.

No.1-10 is configured to first electrode being set as direct current, constant-current characteristics, is on the other hand set as wire speed control Fixed speed control.Direct current, constant-current characteristics the source of welding current generally use non-consumable electrode type, i.e. not from consumption welding wire and from on-consumable tungsten electricity Pole generates the power mode used in TIG weld, plasma welding connection of electric arc, but the control of arc length and droop characteristic phase Together, the upper and lower of electrode side is needed.Even if this power supply is used as consumable electrode type, the electric arc in the case where welding wire is set as fixed speed control Long static stabilization also absolutely not plays.Therefore, identical as No.1-9, arc length changes larger always, cannot achieve stable Welding.Root pass shape and surface layer weld bead shape are more coarse and unstable, and inside also generates lack of fusion.

In No.1-11, replaced with directly for existing whole electrodes from exchange, droop characteristic, voltage FB speed Control Stream, constant-current characteristics, voltage FB speed Control, but first electrode does not become constant-voltage characteristic, fixed speed control, therefore, root weldering Road shape is unstable.About surface layer weld bead shape, constant-current characteristics, voltage FB speed Control play a role, although having found because straight Flow distinctive electric arc interfere caused by unstability, but be in allowed band.

(second embodiment and the second comparative example)

Fig. 5 is the figure for illustrating the structure of the experimental provision in second embodiment and the second comparative example.It needs to illustrate , the basic structure of experimental provision shown in fig. 5 is to remove the 4th welding unit 40 from welder 1 shown in FIG. 1 and obtain It arrives.Here, also being shown together together with experimental provision in Fig. 5：Workpiece comprising the first steel plate 201 and the second steel plate 202 200, to the surface side of workpiece 200 supply surface layer solder flux 300, configuration workpiece 200 back side backing plate portion 400 and The welding metal 500 of workpiece 200 is formed in welding.

In addition, Fig. 7 (b) shows the size of each steel plate and groove in second embodiment and the second comparative example.At this In example, the first steel plate 201 and the second steel plate 202 use plate thickness 30mm, width 500mm × length 3000mm tensile strength are 400Mpa grades of carbon steel sheet carries out groove end face processing to above-mentioned steel plate respectively, becomes banjo fixing butt jointing.Bevel shape is from surface Become 45 ° of V-types at 25mm, remaining plate thickness 5mm is vertically root face.Root gap becomes the contact of two sides steel plate in most short portion 0mm, but due to the deformation of steel plate, inevitably there is the position in the gap for generating maximum 2mm.Each welding wire (the first welding wire 110 ~third welding wire 130) use the corresponding product of JIS Z3351 YS-S6, surface layer solder flux 300 to use JIS Z3352 SACI1's Corresponding product.Surface layer solder flux 300 is in the forward position of than first electrode (first pole) and second electrode and third electricity It is automatically continuously spread between pole appropriate.

In divided edge of steel plate back side, as backing plate portion 400, not using formation solid as copper sheet, ceramic wafer, but The backing plate solder flux 412 that joined curable resin ingredient is spread on a small quantity on lower surfacing agent 411, and from across lower surfacing agent 411 Inside air hose 413 inject gas, backing plate solder flux 412 is thus pressed on into the steel plate back side.In addition, about each electrode, Between corresponding ignition tip and steel plate, wiring has the independent source of welding current.It should be noted that each welding wire is arranged on The feed rolls of the surface of each ignition tip are sent to weld part.

Then, using experimental provision shown in fig. 5, the test of three electrode single side buried arc welding methods has been carried out.More specifically For, using experimental rig shown in fig. 5, gage of wire, feeding classification, external behavior, welding wire speed are made as unit of electrode Degree control, welding current, weldingvoltage change, to confirm its influence.In experimental provision shown in Fig. 5, first The interpolar of the front end of welding wire 110 and the front end of the second welding wire 120 distance is 40mm, the front end of the second welding wire 120 and third welding wire The distance of 130 front end is 120mm.Moreover, the speed of welding in this is 47 (cm/min).

As test result, root pass shape, surface layer weld bead shape, internal flaw are evaluated.Root pass shape exists The following are ideal forms by width 9mm or more, root height 2mm or more and 5mm, and the few feelings of small, width deviation that will wriggle Condition is set as very good and is set as A, will be due to root pass shape by above-mentioned evaluation elementary errors but without being set as B the case where modifying Shape bad and need the case where being modified to be set as C and handle to be unqualified.About surface layer weld bead shape, welded using with root The identical evaluation criteria of road shape.About internal flaw, even if ultrasonic test, section macroscopic view cutting test will be carried out The case where the case where not finding defect is set as "None", will confirm that out lack of fusion is set as " having ".

Table 3 and table 4 show second embodiment and manufacturing condition and test result in the second comparative example.Here, No.2-1~No.2-4 shown in table 3 is second embodiment, and No.2-5~No.2-10 shown in table 4 is the second comparative example.

[table 3]

[table 4]

Firstly, being illustrated to second embodiment.

No.2-1 uses direct current, constant-voltage characteristic, fixed speed control to first electrode, uses always after second electrode Since exchange, droop characteristic, voltage FB speed Control, obtain good root pass shape.In addition, by that will become most The third electrode in whole path is set as exchange, droop characteristic, voltage FB speed Control, and the appearance of surface layer weld bead shape also becomes non- Chang Hao.

No.2-2 is the differential of the external behavior in the source of welding current of second and third electrode relative to No.2-1 Value dV/dI is larger, weakens the case where constant-current characteristics.When constant current dies down, arc voltage is also difficult to happen variation, arc length Feedback control be still difficult to play a role.Therefore, although within the allowable range, making compared with root pass shape to arc length Bigger surface layer weld bead shape is influenced caused by stability to be deteriorated.That is, giving following enlightenment：In order to become surface layer weld bead shape Good, more preferable differential value dV/dI small voltage FB speed Control.

Whole electrodes are set as direct current, constant-voltage characteristic, fixed speed control by No.2-3, and are also taken later to second electrode Reduce the control of the pressure change in molten bath, thus to obtain extraordinary root pass shape.On the other hand, although in allowed band It is interior, but surface layer weld bead shape because direct current side by side caused by interfere between electric arc due to it is slightly at random, therefore the case where with using exchanging Compared to slightly worse.

No.2-4 uses direct current, constant-voltage characteristic, fixed speed control to first electrode, and on the other hand, second electrode uses Direct current, constant-current characteristics, voltage FB speed Control, third electrode use exchange, constant-current characteristics, voltage FB speed Control.Due to Generated in first and second electrode direct current side by side caused by interfere between electric arc, thus while within the allowable range, but Root pass shape is slightly worse.On the other hand, by using compared with droop characteristic to the subsequent pole for forming surface layer side, constant current is more Excellent constant-current characteristics, thus arc length is more stable, obtains excellent surface layer weld bead shape.

Then, the second comparative example is illustrated.

No.2-5 is set to exchange relative to No.2-1 without first electrode is set as direct current.Constant-voltage characteristic, perseverance Speed control is scope of the invention, but due to being set as exchanging, exchanging distinctive periodic electric arc disappearance causes root molten Pond it is unstable, stable root pass shape can not be obtained.

No.2-6 is typical example used at present.Whole electrodes use exchange, droop characteristic, voltage FB speed Control. Although special problem is not present in internal flaw, surface layer weld bead shape, be set as exchange and both speed Controls for Be for root weld it is unsuitable, root pass shape generate it is bad.

First electrode, the third electrode of No.2-7 is in scope of the invention, but hands over second electrode combination Stream, droop characteristic, electric current FB speed Control.In droop characteristic, relative to arc length variation and electric current hardly happens variation, because , as arc length control method for use, the feedback control of standby current is poorer than executed arc voltage feedback for this.The control of arc length rises in which can not be successfully Effect, and welding wire feeding is also non-constant, therefore, not only generates the bad of root pass shape, also generates the inside of lack of fusion Defect, surface layer weld bead shape it is bad.

In No.2-8, for whole electrodes, the constant-current characteristics for further enhancing constant current, electric current are combined with to droop characteristic FB speed control.It carries out the control of arc length with can not be successfully, and welding wire feeding is also not constant, therefore, not only generates root weldering Road shape it is bad, also the generation internal flaw of lack of fusion, surface layer weld bead shape it is bad, overall quality ratio No.2-7 is more Difference.

In No.2-9, constant-voltage characteristic, voltage FB speed Control are combined with as first electrode.In constant-voltage characteristic, phase Variation for arc length, voltage hardly happen variation, therefore, as arc length control method for use, monitor the feedback control of voltage Performance is low, and the welding wire feeding speed for forming first electrode of root pass is constant, this is most for dimensionally stable Important, therefore, in this configuration, good root pass shape can not be obtained.In addition, since first electrode is formed by Bonding layer it is significant unstable, be based on the reason, also produce lack of fusion in the fluidic junction with second electrode.

It is combined with direct current, constant-current characteristics, fixed speed control as first electrode in No.2-10, but in the combination, arc Long Stabilization Control does not work, therefore welding is unstable, not only root pass shape defect, since first electrode is made At bonding layer it is significant unstable, also produce lack of fusion in the fluidic junction with second electrode.

(3rd embodiment and third comparative example)

Fig. 6 is the figure for illustrating the structure of the experimental provision in 3rd embodiment and third comparative example.It needs to illustrate , the basic structure of experimental provision shown in fig. 6 is to remove third welding unit the 30, the 4th from welder 1 shown in FIG. 1 Obtained from welding unit 40 and the second welding flux feeding device 80.Here, also being shown together together with experimental provision in Fig. 6： Workpiece 200 comprising the first steel plate 201 and the second steel plate 202, is matched at the surface layer solder flux 300 supplied to the surface side of workpiece 200 It sets in the backing plate portion 400 of the back side of workpiece 200, be formed in welding the welding metal 500 and in advance of workpiece 200 The groove packing material 600 supplied to groove.

In addition, Fig. 7 (c) shows the size of each steel plate and groove in 3rd embodiment and third comparative example.At this In example, the first steel plate 201 and the second steel plate 202 use plate thickness 14mm, width 500mm × length 3000mm tensile strength are 520Mpa grades of carbon steel sheet carries out groove end face processing to above-mentioned steel plate respectively, becomes banjo fixing butt jointing.Bevel shape is no root face 50 ° of V-types.Root gap becomes the 0mm of two sides steel plate contact in most short portion, but due to the deformation of steel plate, inevitably has There is the position in the gap for generating maximum 2mm.Each welding wire (the first welding wire 110 and the second welding wire 120) uses JIS Z3351 YS- The corresponding product of S6, surface layer solder flux 300 use the corresponding product of JIS Z3352 SACI1.Surface layer solder flux 300 is in than first electricity The forward position in pole (first pole) automatically continuously spreads appropriate.In addition, it is different from surface layer solder flux 300, it in advance manually will be by iron The groove packing material 600 that powder is constituted is dispersed in groove.The packed height of groove packing material 600 is managed as from steel plate table It rises at 3mm face position.The groove packing material 600 is melted in welding with each welding wire, surface layer solder flux 300 together, forms molten bath.

In divided edge of steel plate back side, as backing plate portion 400, without using formation solid or welding with backing as copper sheet, ceramic wafer Agent, but attached through braided glass fibre and formed the thick soft backing material 421 for being referred to as glass tape of several mm.Due to Glass tape is soft, therefore not will receive wavy etc. the influence of steel plate, can be in close contact with the back side.In welding, electric arc is attached It closely melts, but non-melt portion plays the effect of liner and has the function of the excessive burn-off for preventing root.In addition, about each Electrode, wiring has the independent source of welding current between corresponding ignition tip and steel plate.It should be noted that each welding wire is set The feed rolls in the surface of each ignition tip are set to send to weld part.

Then, using experimental provision shown in fig. 6, in addition to a part of (aftermentioned No.3-8), bipolar electrode single side is carried out The test of buried arc welding method.More specifically, using experimental rig shown in fig. 6, gage of wire, feedback are made as unit of electrode Electric mode, external behavior, wire speed control, welding current, arc voltage change, to confirm its influence.In Fig. 6 Shown in experimental provision, the interpolar distance of the front end of the front end of the first welding wire 110 and the second welding wire 120 is 70mm.Moreover, should Though the speed of welding in example under each manufacturing condition to be constant, it is different according to the difference of manufacturing condition.It needs to illustrate It is that No.3-8 is the test based on the single electrode single side buried arc welding method that the first welding wire 110 is used only.

As test result, root pass shape, surface layer weld bead shape, internal flaw are had rated.Root pass shape exists The following are ideal forms by width 6mm or more, root height 1mm or more and 4mm, and the few feelings of small, width deviation that will wriggle Condition is set as very good and is set as A, will be due to root pass shape by above-mentioned evaluation elementary errors but without being set as B the case where being modified Shape bad and need the case where being modified to be set as C and handle to be unqualified.About surface layer weld bead shape, welded using with root The identical evaluation criteria of road shape.About internal flaw, even if ultrasonic test, section macroscopic view cutting test will be carried out The case where the case where not finding defect is set as "None", will confirm that out lack of fusion is set as " having ".

Table 5 and table 6 show 3rd embodiment and manufacturing condition and test result in third comparative example.Here, No.3-1~No.3-4 shown in table 5 is 3rd embodiment, and No.3-5~No.3-14 shown in table 6 is third comparative example.

[table 5]

[table 6]

Firstly, being illustrated to 3rd embodiment.

No.3-1 has used direct current, constant-voltage characteristic, fixed speed control to first electrode, and second electrode is using all the time Exchange, droop characteristic, voltage FB speed Control, obtain good root pass shape and surface layer weld bead shape.

First electrode is set as the direct current of electrode side-relative to No.3-1 by No.3-2, but passes through the adjustment etc. of voltage, It obtains and No.3-1 same quality.

No.3-3 uses two electrodes direct current, constant-voltage characteristic, the fixed speed control of electrode side-.Such as No.3-1 and No.3- 2 like that, compared with second electrode is set as speed Control, when being set to fixed speed control, although root pass shape is steady Qualitative script is excellent, but by using groove packing material 600, is not found the influence caused by root pass shape.Separately On the one hand, in the case where bipolar electrode method, second electrode for becoming most ultimate is the dominant pole of surface layer weld bead shape, because This, although in the allowed band, by because direct current side by side caused by interfere and influenced between electric arc due to make shape stability It is slightly worse.

In No.3-4, two electrodes are constant-voltage characteristic, fixed speed control, and first electrode is direct current, and second electrode is Exchange.The feeding control that the welding wire of strongest influence is caused on root pass shape is constant speed, and first electrode is adopted Second electrode of surface layer weld bead shape on the other hand is dominated using not by electric arc with the direct current that periodic current interruption is not present Between interference, magnetic blow-out the exchange of influence therefore obtain optimal surface back side quality in the third embodiment.

Then, third comparative example is illustrated.

No.3-5 is typical example used at present.The two poles of the earth are all made of exchange, droop characteristic, voltage FB speed Control.Though Special problem is not present in right internal flaw, surface layer weld bead shape, but is set as exchanging and speed Control this two side is for root Be for portion's welding it is unsuitable, root pass shape it is bad significant.In addition, the steel plate relative to the above embodiments 1,2 Plate thickness it is small, therefore, root pass shape it is bad on surface layer weld bead shape also result in influence and keep its slightly worse.

It is combined with exchange, constant-current characteristics, fixed speed control as first electrode in No.3-6, but in the combination, no It only exchanges distinctive periodic current interruption and adverse effect is caused to root pass shape, the Stabilization Control of arc length does not also act as With therefore, welding is unstable, not only generates the bad of root pass shape, and the bonding layer due to caused by first electrode is shown It writes unstable, also generates lack of fusion in the fluidic junction with second electrode.As first embodiment, second embodiment, if Number of electrodes is more, then the bad of root pass shape caused by first electrode hardly causes shadow to surface layer weld bead shape It rings, but since the example is bipolar electrode construction, the unstable of root pass shape impacts surface layer weld bead shape and leads Deterioration.

First electrode is in scope of the invention using combination as constant-voltage characteristic, fixed speed control in No.3-7, But gage of wire is relatively thin for 2.0mm.As a result, root pass can not be formed, recess is generated in the back side of steel plate.In order to Root pass is formed, needs to take into account stronger arc force and the thickness in the molten bath of the arc force is not interfered to reduce.In order to meet this Combination, reducing current density is effectively that the bigger gage of wire the more advantageous.That is, it is inadequate that gage of wire, which is 2.0mm,.

In No.3-8 using combination as constant-voltage characteristic, fixed speed control in scope of the invention, but in order to simultaneously It completes root pass formation and surface layer welding bead is formed, merely with an electrode with challenge.Wherein, although root pass energy Good shape is enough obtained, but surface layer weld bead shape can not become good.The effect specialization of first electrode is to form root weldering There is limitation in road, therefore, welding condition, surface layer weld bead shape has to become the narrow convex of width.More than two electrodes, Then subsequent pole (especially most ultimate), use is for making surface layer weld bead shape become good welding condition, so as to smooth The thin and convex melting pool shape formed by first pole, but in single electrode construction, it cannot achieve the role-sharing, therefore, for It is inappropriate for root weld.

No.3-9 uses exchange, constant-current characteristics, voltage FB speed Control to first pole.Although internal flaw, surface layer welding bead Special problem is not present in shape, but is inappropriate, root for root weld using exchange and speed Control Portion's weld bead shape it is bad significant.

The first pole of No.3-10, the subsequent pole of No.3-11, No.3-12 use constant-voltage characteristic, voltage FB speed Control, but Either direct current still exchanges, and in constant-voltage characteristic, relative to the variation of arc length, hardly voltage is made to change, therefore, as Arc length control method for use monitors that the performance of the feedback control of voltage is low, therefore welds unstable, root pass shape, surface layer welding bead Shape generates bad order, also generates lack of fusion in fluidic junction.

The subsequent pole of No.3-13, No.3-14 use constant-current characteristics, fixed speed control, but either direct current still exchanges, In the combination, the Stabilization Control of arc length does not work, therefore welds unstable, root pass shape, surface layer weld bead shape Bad order is generated, also generates lack of fusion in fluidic junction.

It should be noted that in the first embodiment, being used as backing plate portion 400 in four electrode single side submerged arc weldings The case where backing plate solder flux 401 and backing plate copper sheet 402, is illustrated.In addition, in a second embodiment, being buried to three electrode single sides It is carried out as backing plate portion 400 using the case where lower surfacing agent 411, backing plate solder flux 412 and air hose 413 in arc welding Explanation.In addition, in the third embodiment, using soft backing plate material as backing plate portion 400 in bipolar electrode single side submerged arc welding The case where expecting 421 is illustrated.But about the quantity of the electrode in multi-electrode single side submerged arc welding and backing plate portion 400 Structure, however it is not limited to which combinations of the above can also suitably change the combination.

Drawing reference numeral explanation

1 ... welder, 10 ... first welding units, 11 ... first feed arrangements, 12 ... first sources of welding current, 20 ... Two welding units, 21 ... second feed arrangements, 22 ... second sources of welding current, 30 ... third welding units, 31 ... thirds feeding dress It sets, 32 ... the third sources of welding current, 40 ... the 4th welding units, 41 ... the 4th feed arrangements, 42 ... the 4th sources of welding current, 50 ... platforms Vehicle driving device, 60 ... control devices, 70 ... first welding flux feeding devices, 80 ... second welding flux feeding devices, 90 ... trolleys, 110 ... first welding wires, 120 ... second welding wires, 130 ... third welding wires, 140 ... the 4th welding wires, 200 ... workpiece, 201 ... first steel Plate, 202 ... second steel plates, 300 ... surface layer solder flux, 400 ... backing plate portions, 500 ... welding metals, 600 ... groove packing materials.

Claims

1. a kind of multi-electrode single side buried arc welding method, used in the multi-electrode single side buried arc welding method first pole and with The first extremely continuous subsequent pole, which is characterized in that

It is described formerly extremely in, using diameter be 4.8mm or more welding wire,

It is described it is subsequent extremely in, using diameter be 2.4mm or more welding wire,

The feed speed of feeding classification and external behavior and each welding wire about the power supply fed to each welding wire Speed control method,

It is described formerly extremely in be set as, the feeding classification be direct current, the external behavior be constant-voltage characteristic, the speed control Mode processed is constant speed control,

It is described it is subsequent extremely in be set as any one of following (a)~(e)：

(a) feeding classification is direct current, and the external behavior is constant-voltage characteristic, and the speed control method is constant speed control System；

(b) feeding classification is exchange, and the external behavior is constant-voltage characteristic, and the speed control method is constant speed control System；

(c) feeding classification is exchange, and the external behavior is constant-current characteristics, and the speed control method is based on electric arc electricity The Voltage Feedback of pressure controls；

(d) feeding classification is exchange, and the external behavior is droop characteristic, and the speed control method is based on electric arc electricity The Voltage Feedback of pressure controls；

(e) feeding classification is direct current, and the external behavior is constant-current characteristics, and the speed control method is based on electric arc electricity The Voltage Feedback of pressure controls,

Gradient for the power supply with the constant-voltage characteristic, as voltage at operating point relative to electric current Differential value dV/dI is -12.0 × 10^-3(V/A) more than.

2. multi-electrode single side buried arc welding method according to claim 1, which is characterized in that

The subsequent pole be configured to include with it is described formerly extremely continuous multiple electrodes,

In each the multiple electrode for constituting the subsequent pole, the feeding classification, the external behavior and the speed Degree control mode is set to any one of described (a) to (e).

3. multi-electrode single side buried arc welding method according to claim 2, which is characterized in that

It is in the multiple electrode for constituting the subsequent pole, from the first pole from when it is most ultimate on rear side of most In, the feeding classification, the external behavior and the speed control method are set to (c) or described (d).

4. multi-electrode single side buried arc welding method according to claim 1, which is characterized in that

For the power supply with the constant-current characteristics or the droop characteristic, as the voltage at operating point relative to The differential value dV/dI of the gradient of electric current is -24.0 × 10^-3(V/A) below.

5. a kind of manufacturing method for welding object, the welding object be by using first pole and with the first extremely continuous subsequent pole Single side submerged arc welding is welded to base material, which is characterized in that