CN1418751A - Large quantity heat conducted welded joint and welding method thereof - Google Patents

Abstract

The present invention provides a welded joint for improving toughness at low temperature in the welded metal and the zone affected by welding heat by welding a steel plate through the large input-heat electro-gas welding with welding input-heat more than 100 KJ/cm. The present invention concretely provides a welded joint and a welding method thereof. The welding metal for the welded joint contains C of 0.03 - 0.12 (mass)%, Si of 0.10 - 0.80 (mass)%, Mn of 0.80 - 2.50 (mass)%, Ni of 0.50 - 3.00 (mass)% , less than Cr of 0.50 (mass)%, less than Mo of 0.50 (mass)%, Ti of 0.01 - 0.10 (mass)% and rare earth elements of 0.0010 - 0.0050 (mass)%. The content of B (mass percent) satisfies f(Q)<= <B> <=0.01, the remaining quantity is iron and inevitable impurities, Q is the welded input-heat (kJ/cm) and f(Q) is the function for Q.

Description

The welding point and the welding method thereof of the welding of a large amount of input pattern of fever

Technical field

The present invention relates to by welding heat input 100 kilojoules/centimetre more than a large amount of input patterns of fever welding point and welding method thereof of welding welding steel ground to obtain.

Background technology

In recent years, along with the progress of the maximization of steel structure and boats and ships, wish that the bigger requirement of the more high and thick degree of intensity of used steel plate is more and more higher.In the welding of steel plate,, adopted the welding of a large amount of input such as electrogas arc welding, electroslag welding, submerged-arc welding pattern of fever in order to improve welding efficiency.But when welding heat input increased, because of weld metal and welding heat affected zone are under the high temperature for a long time, this caused thickization of tissue, and its toughness worsens.

Especially in the shipbuilding field,, adopted such technology along with the maximization of container ship, promptly be used for sheerplank by the disposable welding of vertical electrogas arc welding and thickness of slab surpass 60 millimeters steel plate.In that the such thickness of slab of disposable welding surpasses under the occasion of 60 millimeters steel plate by electrogas arc welding, welding heat input increase to less than 500 kilojoules/centimetre, thereby weld metal and welding heat affected zone are under the high temperature for a long time, and this has caused thickization of tissue.As a result, the toughness of weld metal and welding heat affected zone worsens.

On the other hand, in fields such as building, bridge, in submerged-arc welding, adopted such technology, promptly, use to be added with the solder flux of iron powder and to attempt to increase welding electrode (so-called series connection welding and three electrode welding etc.), result in order to increase the fusion amount, electric current height and the high welding of fusion amount can be carried out, steel plate can be welded once up to 80 millimeters thick.In addition, in electroslag welding, also adopted the technology of welding the thick steel plate of 100 millimeter.Under the occasion of the steel plate such by submerged-arc welding and the disposable welding of electroslag welding, welding heat input surpass 500 kilojoules/centimetre, thereby weld metal and welding heat affected zone are under the high temperature for a long time, this has caused thickization of tissue.As a result, the toughness of weld metal and welding heat affected zone worsens.

Therefore, for the toughness that prevents weld metal and welding heat affected zone worsens, known such technology, promptly by make titanium nitride fine be dispersed in the steel plate and with the titanium nitride for the ferrite transformation core prevents to organize thickization by what welding heat input caused, and generated trickle ferrite.But, under the occasion of importing the pattern of fever welding in a large number, owing to welding heat affected zone is under the high temperature for a long time, thus be scattered in the titanium nitride decomposition in the steel plate and produced nitrogen, the result, the toughness of welding heat affected zone worsens.

In the flat 6-71447 of Japanese Unexamined Patent Publication No, disclosed such method, promptly import pattern of fever when welding in a large number, near heating weld part before and after the welding and control the cooling velocity of welding heat affected zone, preventing thickization of organizing of welding heat affected zone thus.But, import pattern of fever when welding in a large number actual, for the weld part of heating large welding point, manpower that need cost a lot of money and expense are difficult in that welding is on-the-spot to be carried out such heat treated ground and control cooling velocity.

In addition, in the flat 10-109189 of Japanese Unexamined Patent Publication No number peaceful 10-180488 number, disclosed such welding wire that is added with solder flux that is used for the pneumoelectric arc welding,, stipulated the steel crust of welding wire and the composition of its inner solder flux promptly in order to improve the low-temperature flexibility of weld metal.But, under the occasion of the pneumoelectric arc welding (being electrogas arc welding) of importing heat in a large number, owing to weld metal is under the high temperature for a long time, so, still caused thickization of weld metal tissue even if use these welding wires that is added with solder flux.As a result, the toughness of weld metal worsens.

On the other hand, in the flat 7-328793 of Japanese Unexamined Patent Publication No number and 2000-107885 number, disclosed such solder flux and solid welding wire, promptly they are used in the submerged-arc welding of a large amount of input patterns of fever and have obtained the strong weld metal of toughness.But, welding heat input 100 kilojoules/centimetre more than the occasion of a large amount of input pattern of fever submerged-arc welding under, even if adopt these solder flux and solid welding wire, still can't realize the granular and the homogenising of weld metal microstructure fully, prevent that the effect of weld metal toughness deterioration is also good inadequately.

And, the flat 10-109189 of Japanese Unexamined Patent Publication No number, flat 7-328793 number, 2000-107885 number described welding material are to be the material of purpose to improve weld metal toughness only, since can not prevent welded-joint and welding heat affected zone the deterioration of toughness, worsen so can not realize the toughness that prevents whole welding joints.

Summary of the invention

The purpose of this invention is to provide eliminate above-mentioned defective, improve by welding heat input 100 kilojoules/centimetre more than the weld metal that forms of a large amount of input patterns of fever welding welding steels and the welding point and the welding method thereof of the low-temperature flexibility of welding heat affected zone.

Promptly, the present invention be by welding heat input 100 kilojoules/centimetre more than the weld metal that forms of a large amount of input patterns of fever welding welding steels and the welding point and the welding method thereof of the low-temperature flexibility of welding heat affected zone, wherein, the weld metal of welding point has such composition, be C0.03 weight %-0.12 weight %, Si 0.10 weight %-0.80 weight %, Mn 0.80 weight %-2.50 weight %, Ni 0.50 weight %-3.00 weight %, below the Cr 0.50 weight %, below the Mo 0.50 weight %, Ti 0.01 weight %-0.10 weight %, rare earth element 0.0010 weight %-0.0050 weight %, and the content of B (mass percent) satisfies following formula (1), surplus is iron and unavoidable impurities

f(Q)≤[B]≤0.01???????????????(1)

Q: welding heat input (kJ/cm)

F (Q): the function of Q

The content of [B]: B (mass percent).

In foregoing invention, as first preferred implementation, the weld metal of welding point is at the V and the Nb below the 0.10 weight % that preferably also contain on the basis of mentioned component below the 0.10 weight %.

In addition, as second preferred implementing form, importing pattern of fever welding in a large number is to import the pattern of fever electrogas arc welding in a large number, and f (Q) is preferably according to the function of following formula (2).

f(Q)＝0.003×{0.23×ln(Q)-0.5}????(2)

Ln (Q): the natural logrithm of Q.

In addition, as the 3rd preferred implementing form, importing pattern of fever welding in a large number is to import pattern of fever submerged-arc welding in a large number or import the pattern of fever electroslag welding in a large number, and f (Q) is preferably according to the function of following formula (3).

f(Q)＝0.003×{0.42×ln(Q)-1.9}????(3)

Description of drawings

Fig. 1 is the sectional view of electrogas arc welding joint and groove.

Fig. 2 represents the cross section and the pendulum impact test sheet interception position of electrogas arc welding weld part.

Fig. 3 is the sectional view of submerged-arc welding joint and groove.

Fig. 4 represents the cross section and the pendulum impact test sheet interception position of submerged-arc welding weld part.

Fig. 5 is the sectional view of electroslag welding joint and groove.

Fig. 6 represents the cross section and the pendulum impact test sheet interception position of electroslag welding weld part.

Concrete form of implementation

The inventor to improve by welding heat input 100 kilojoules/centimetre more than the electrogas arc welding of a large amount of input pattern of fever, import pattern of fever submerged-arc welding or import weld metal that a large amount of input patterns of fever welding welding steels such as pattern of fever electroslag welding form in a large number and the low-temperature flexibility of welding heat affected zone has been carried out lucubrate in a large number, the result has obtained following understanding.

That is, in weld metal, the occasion of welding at a large amount of input patterns of fever is the full occasion of cooling velocity, keeps time lengthening at high temperature, goes out inferior ferrite of separating out and grows up, thereby low-temperature flexibility is worsened.Therefore, for improving the low-temperature flexibility of weld metal, must adjust the quantity that adds the various alloying elements in the weld metal, when improving weld metal quenching degree, do not obtain thick ferritic structure, thereby make whole weld metal become trickle microstructure equably.

On the other hand, in welding heat affected zone, be included in the nitrogen in the steel plate as unavoidable impurities and add the decomposition of the titanium nitride of coming in because of thinning microstructure and the nitrogen that produces is the cause that low-temperature flexibility is worsened.Therefore, for improving the low-temperature flexibility of welding heat affected zone, must make the nitrogen that is present in the welding heat affected zone and other element chemical combination and being fixed with the form of nitride.

Therefore, the inventor's the starting point is, in weld metal and welding heat affected zone were kept at high temperature a large amount of input patterns of fever welding for a long time, B was diffused into from weld metal in the welding heat affected zone, and its diffusion depends on welding heat input.

That is, make weld metal contain the low-temperature flexibility that B ground improves the quenching degree of weld metal and improves weld metal.In addition, B is diffused into welding heat affected zone and the nitrogen that is present in the welding heat affected zone is fixed up with the form of boron nitride from weld metal, so, can improve the low-temperature flexibility of welding heat affected zone.And, in welding heat affected zone, also demonstrate boron nitride nucleation ground and generate trickle ferritic effect, therefore, B is the element that effectively improves the low-temperature flexibility of weld metal and welding heat affected zone.The inventor has recognized the advantage of adding the B of the quantity that can bring into play above effect.

In the present invention, illustrate limit by welding heat input 100 kilojoules/centimetre more than the electrogas arc welding of a large amount of input pattern of fever, import pattern of fever submerged-arc welding or import the reason of the weld metal composition of the welding point that a large amount of input patterns of fever welding such as pattern of fever electroslag welding obtains in a large number in a large number.

C:0.03 weight %-0.12 weight %

C guarantees weld metal intensity and improves the required element of quenching degree.C content can't obtain sufficiently high quenching degree less than 0.03 weight %.On the other hand, if surpass 0.12 weight %, then not only in weld metal, produce the high temperature cracking, and low-temperature flexibility is worsened with forming martensitic phase.Therefore, C must satisfy the scope of 0.03 weight %-0.12 weight %.Preferably satisfy 0.05 weight %-0.10 weight %.

Si:0.10 weight %-0.80 weight %

Si is except having deoxidation, and it still improves weld metal intensity element.If Si content is less than 0.10 weight %, then the flowability of weld metal is poor, and occurs weld defect such as groove incomplete fusion easily, and the efficient of weld job reduces.On the other hand, if surpass 0.80 weight %, the high temperature cracking takes place in weld metal then.Therefore, Si must satisfy the scope of 0.10 weight %-0.80 weight %.0.15 weight %-0.50 weight % preferably.

Mn:0.80 weight %-2.50 weight %

Mn is the element of guaranteeing weld metal intensity and improving quenching degree.If Mn content then can not obtain sufficiently high quenching degree less than 0.80 weight %.On the other hand, if surpass 2.50 weight %, the high temperature cracking phenomena of weld metal then not only occurs, and generate upper bainite or martensitic phase, thereby low-temperature flexibility is worsened.Therefore, Mn must satisfy the scope of 0.80 weight %-2.50 weight %.1.00 weight %-2.00 weight % preferably.

Ni:0.50 weight %-3.00 weight %

Ni improves the intensity of weld metal and the element of toughness.If less than 0.50 weight %, starving, Ni content can't obtain the sufficiently high welding point of intensity.On the other hand,, the high temperature cracking phenomena then not only in weld metal, occurs, and generate upper bainite or martensitic phase, thereby low-temperature flexibility is worsened if surpass 3.00 weight %.Therefore, Ni content must satisfy the scope of 0.50 weight %-3.00 weight %.0.50 weight %-2.00 weight % preferably.

Below the Cr:0.50 weight %

Cr improves the intensity of weld metal and the element of toughness.For obtaining the Cr more than the necessary 0.02 weight % of interpolation of such effect.If Cr content surpasses 0.50 weight %, the high temperature cracking phenomena of weld metal then not only takes place, and generate upper bainite or martensitic phase, thereby low-temperature flexibility is worsened.Therefore, Cr gets below the 0.50 weight %.0.05 weight %-0.40 weight % preferably.

Below the Mo:0.50 weight %

Mo is the same with V, Nb all to be to improve weld metal intensity and make structure refinement ground improve the element of low-temperature flexibility in the welding of a large amount of input pattern of fever.For obtaining such effect, must add the above Mo of 0.02 weight %.If Mo content surpasses 0.50 weight %, the high temperature cracking of weld metal then takes place.Therefore, Mo gets below the 0.50 weight %.0.10 weight %-0.45 weight % preferably.

Below the V:0.10 weight %

V is the same with Mo, Nb all to be to improve weld metal intensity and make structure refinement ground improve the element of low-temperature flexibility in the welding of a large amount of input pattern of fever.For obtaining such effect, must add the above V of 0.005 weight %.If V content surpasses 0.10 weight %, the high temperature cracking of weld metal then takes place.Therefore, containing under the occasion of V the content that preferred 0.10 weight % is following.0.01 weight %-0.07 weight % preferably.

Below the Nb:0.10 weight %

Nb is the same with Mo, V all to be to improve weld metal intensity and make structure refinement ground improve the element of low-temperature flexibility in the welding of a large amount of input pattern of fever.For obtaining such effect, must add the above Nb of 0.005 weight %.If Nb content surpasses 0.10 weight %, the high temperature cracking of weld metal then takes place.Therefore, containing under the occasion of Nb the content that preferred 0.10 weight % is following.0.01 weight %-0.07 weight % preferably.

Ti:0.01 weight %-0.10 weight %

Ti has by forming oxide and be the effect that the core ground trickle ferritic phase of generation improves the low-temperature flexibility of weld metal with this oxide in weld metal.If Ti contains quantity not sufficient 0.01 weight %, then can not get improving the effect of ground temperature toughness inadequately because of oxide formation amount.On the other hand, if surpass 0.10 weight %, then weld metal hardens and causes that low-temperature flexibility worsens.Therefore, Ti must satisfy the scope of 0.01 weight %-0.10 weight %.0.02 weight %-0.06 weight % preferably.

Rare earth element: 0.0010 weight %-0.0050 weight %

Rare earth element is the general name that belongs to the element of periodic table three races, and the S in they and the weld metal makes the sulfide disperse separate out in combination and has an effect that the weld metal toughness that prevents to be caused by S reduces.If the content of rare earth element less than 0.0010 weight %, does not then generate sulfide fully, S's is fixing not enough, so low-temperature flexibility worsens.On the other hand, if surpass 0.0050 weight %, then weld metal sclerosis and cause the deterioration of low-temperature flexibility.Therefore, rare earth element must satisfy 0.0010 weight %-0.0050 weight %.0.0020 weight %-0.0040 weight % preferably.In the present invention, though rare earth element is not limited to element-specific, the element that preferred Ce, La, Nd etc. have bought easily at a low price.

In addition, the necessary diffusion length D of B relatively of B content (weight %) _BSatisfy following formula (1) (μ m).

f(Q)≤[B]≤0.01???????????(1)

Q: welding heat input (kJ/cm)

F (Q): the function of Q

The content of [B]: B (mass percent).

B has intensity that improves weld metal and welding heat affected zone and the effect that improves low-temperature flexibility, and it is to constitute most important element of the present invention.That is, because B is the element that improves quenching degree, so, improve the quenching degree of weld metal by in weld metal, there being B, the result, low-temperature flexibility has improved.And B also so has the effect of the low-temperature flexibility of further raising weld metal, promptly suppresses thick once ferritic growth and generate trickle ferritic phase in weld metal.

In addition, B is diffused into welding heat affected zone from weld metal.Like this, be diffused into welding heat affected zone from weld metal, improved the quenching degree of welding heat affected zone by making B, the result, low-temperature flexibility improves.In addition, B decomposes the N that produces with the TiN that is contained in the N in the steel plate as unavoidable impurities and adds for thinning microstructure because of the welding heat input and forms BN in combination, has fixed N thus also and then prevent the deterioration of low-temperature flexibility.And, owing to being that core ground generates trickle ferrite with BN, there is the effect that further improves the low-temperature flexibility of welding heat affected zone.

The major function of B of the present invention is to be diffused into heat affected zone and near fixing time solid solution N as BN ground in the heat affected zone of weld metal from weld metal.And solid solution N is the lysigenous material of TiN that is present in precipitate in material in the steel and the steel as unavoidable impurities.This function and welding method military officer, if the diffusion length of B increases, then in order to guarantee certain B concentration in range of scatter, considering to increase B content.Therefore, can suppose that the required B in the weld metal measures and diffusion length D _B(μ m) is proportional.

The diffusion length D of B _B(μ m) is by the type of cooling (cooling experience) decision in when welding.B in steel diffusion is considered to be right after solidifies at weld metal that the back takes place, therefore, and to studying from 1500 ℃ to 1100 ℃ cooling procedure.In other words, be every kind of welding method decision thickness of slab and groove shape and roughly definite welding heat input Q (being the input heat (kJ/cm) of unit weld length), the type of cooling of heat affected zone changes corresponding to this welding heat input Q (kJ/cm).Therefore, in the actual welding joint that is formed by each welding method, the actual measurement temperature is obtained cool time, the cooling velocity from 1500 ℃ to 1100 ℃ and can be had diffusion equation to calculate the diffusion length D of B _B(μ m).The diffusion length D ' that is calculating like this _BBetween (μ m) and the welding heat input Q good correlation is arranged, this is with representing according to the relational expression of obtaining by experience.But, when welding method not simultaneously, welding heat input Q (kJ/cm) even if identical, be different from 1500 ℃ to 1100 ℃ cooling velocities, therefore, the calculating diffusion length D ' of B _B(μ m) must set according to every kind of welding method with the relational expression of welding heat input Q (kJ/cm).

In other words, be under the occasion of a large amount of input pattern of fever electrogas arc welding more than the 100kJ/cm at welding heat input, calculate diffusion length D ' _B(μ m) represents with following formula (4).

D′ _B＝0.23×ln(Q)-0.5??????(4)

In addition, be under the occasion of a large amount of input pattern of fever submerged-arc welding more than the 100kJ/cm at welding heat input, calculate diffusion length D ' _B(μ m) represents with following formula (5).

D′ _B＝0.42×ln(Q)-1.9????(5)

In addition, under the occasion of electroslag welding, the heat cycle during owing to welding is the same with the submerged-arc welding weldering, so also set up with the relation of (5)-sample.

Subsequently, the measured value according to the diffusion length of the toughness of the heat affected zone of joint and B obtains proportionality coefficient 0.003 according to experience.That is the following 0.003 * D ' that limits the use of of the B content (weight %) in the weld metal, _BExpression.

In other words, under the occasion of B content (weight %), can not get improving the effect of the low-temperature flexibility of weld metal and welding heat affected zone less than the value of the index α that calculates with following formula (6).

α＝0.003×D′ _B??????????(6)

D ' _BBe the calculating diffusion length (μ m) of B.

On the other hand, if B content 0.01 weight %, then the quenching degree of weld metal and heat affected zone is too high, and the high temperature cracking of weld metal and welding heat affected zone not only takes place, and because of generating martensitic phase low-temperature flexibility is worsened.

Therefore, B content (weight %) must satisfy following formula (1).

f(Q)≤[B]≤0.01?????????????????(1)

Q: welding heat input (kJ/cm)

F (Q): the function of Q

The content of [B]: B (weight %).

Here, be under the occasion of a large amount of input pattern of fever electrogas arc welding more than the 100kJ/cm at welding heat input, calculate diffusion length D ' _B(μ m) can accurately calculate with above-mentioned formula (4), becomes thus:

f(Q)＝0.003×{0.23×ln(Q)-0.5}????(2)

And be under the occasion of a large amount of input pattern of fever submerged-arc welding more than the 100kJ/cm at welding heat input, calculate diffusion length D ' _B(μ m) can accurately calculate with above-mentioned formula (5), becomes thus:

f(Q)＝0.003×{0.42×ln(Q)-1.9}????(3)

Under the occasion of electroslag welding, also set up with the same relation of formula (3).

For weld metal is adjusted in the proper range of afore mentioned rules, be necessary for the composition that every kind of welding method is considered the steel plate composition, welding wire and the solder flux that are welded.

In the present invention, preferred steel are described.

From the viewpoint of the toughness of guaranteeing welding heat affected zone,, preferably suppress the steel of alloying element addition as the steel that are used for importing in a large number the pattern of fever welding.For example, preferably utilize the mild steel (Ceq≤0.45%, Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Ni+Cu)/15) of TMCP (hot mechanism control method).For example, the composition of the steel plate of representative is: C 0.03 weight %-0.15 weight %, Si 0.05 weight %-0.50 weight %, Mn 0.5 weight %-2.5 weight % is below the P 0.006 weight %, below the S 0.006 weight %, Al 0.005 weight %-0.06 weight % is below the Ni 1.50 weight %.In addition, organize chap big for preventing heat affected zone, we think preferred and add Ti 0.01 weight %-0.04 weight % and N 0.003 weight %-0.008 weight % and make the TiN particle be scattered in steel in the steel.In the used steel plate of the present invention, for guaranteeing steel strength, if desired, preferably add: below the Ni 3.0 weight %, below the Nb 0.1 weight %, below the V 0.10 weight %, below the Cr 1.0 weight %, below the Cu 1.5 weight %, below the Mo 0.8 weight %, B 0.0003 weight %-0.0040 weight % organizes chap big in order to prevent heat affected zone, adds Ca 0.0005 weight %-0.0040 weight % and/or rare earth element (REM) 0.001 weight %-0.020 weight %.Except TiN, also can be that the oxide of Ca and REM and sulfide disperse are in steel.

Below, explanation in the present invention is preferred for the welding wire and the solder flux of every kind of welding method.

Under the situation of electrogas arc welding, from the viewpoint of welding efficiency, operation, adopting thin welding wire (1.6 millimeter) is flux cored wire (FCW), in order to increase the fusion amount, is preferably in a large amount of alloyed powders that add based on iron powder in the solder flux.The weld metal composition adjustment of electrogas arc welding is mainly carried out easily because of added alloy in the solder flux of FCW.For example, preferred Ni, Cr, rare earth element etc. are added to method in solder flux with ferroalloy form, B etc. such as FeMn, FeNb with oxide form such as B2O3 and according to aequum with form of powder, Mn, Nb etc. separately.In addition, must consider the dilutedly decision addition of steel plate to weld metal.

Under the situation of submerged-arc welding, from the viewpoint of the mechanical property of guaranteeing welding efficiency, operation, weld metal etc., using thickness is 4.0 millimeters-6.4 millimeters solid welding wire and sintered flux.Especially, in disposable a large amount of input patterns of fever welding, be to increase the fusion amount, preferably adopt multi-electrodeization (electrode of promptly connecting welding, the welding of three electrodes) and contain the solder flux of iron powder.In submerged-arc welding, although can add alloy and carry out the adjusting of weld metal composition thus welding wire, solder flux, under the occasion of welding wire, preferably select to have considered the alloy additive process of stretch process, and under the occasion of solder flux, preferably selected to consider the alloy additive process of weld job etc.

Under the occasion of electroslag welding, extensively adopt the solid welding wire that uses thin (1.6 millimeter) and the non-consumable electrode type electroslag welding of fusion solder flux from operating efficiency, easy construction consideration.In the electroslag welding of non-consumable type, the composition of weld metal is regulated mainly and is undertaken by add alloy in solid welding wire, must consider the dilutedly decision addition of steel plate to weld metal.

In addition, the welding method that is suitable for of the present invention also can be applicable to gas shielded arc welding except that electrogas arc welding, submerged-arc welding and electroslag welding.

But, in order to utilize B in the weld metal to the diffusion of welding heat affected zone, and diffusion effect is obvious in the occasion that a large amount of input patterns of fever that the toughness that adopts welding heat affected zone significantly worsens and cooling velocity is slow weld, so especially welding heat input 100 kilojoules/centimetre more than occasion under, obtain remarkable result.

So, by in weld metal, adding an amount of B, can improve by welding heat input 100 kilojoules/centimetre more than the weld metal of the welding point that forms of a large amount of input patterns of fever welding welding steels and the low-temperature flexibility of welding heat affected zone.

Embodiment 1

Carry out welding heat input 100 kilojoules/centimetre more than the electrogas arc welding of a large amount of input pattern of fever and make the welding point of steel plate.

The thickness and the composition of steel plate are as shown in table 1.In addition, it is as shown in table 2 to be used for the composition of the welding wire that contains solder flux (hereinafter referred to as welding wire) of used electrogas arc welding.Each constituent content (weight %) expression shown in the table 2 accounts for the ratio of welding wire gross mass (being the total quality of steel crust and solder flux).

Welding condition is as shown in table 3.When making the welding point of steel plate B (thick 40 millimeters) and steel plate C (thick 60 millimeters), for preventing weld defect, on thickness of slab direction make electrode vibration on one side, weld on one side.

Like this, steel plate A-C and welding wire 1-31 are combined in every way, 100 kilojoules/centimetre more than welding heat input under carry out electrogas arc welding, make its shape welding point as shown in Figure 1 thus.The composition (weight %) of welding heat input when making each welding point (kJ/cm) and the weld metal that obtained is as shown in table 4.

In addition, as shown in Figure 2, after 1 millimeter, cut out three soldering test sheets (2 millimeters V notch test sheets of JIS4 number) from weld metal and welding heat affected zone on the surface that grinds away each welding point respectively, handle and carry out pendulum impact test according to the regulation of JIS Z 2242.Incision site is got the welding heat affected zone (so-called junction surface) that weld metal central portion and molten thread and otch intersect.-40 ℃ pendulum absorbs can vE _-40(J) be the mean value of three of test films and as shown in table 4.α value in the table 4 is the value of calculating with (2) formula.

Below, instruction card 4.Example 1-12 is the example that welding heat input (kJ/cm) and weld metal composition (weight %) satisfy the scope of the invention.

Comparative example 1-6 is that B content is at the extraneous example of (1) formula.Compare the 7, the 8th, the example of carbon content outside the scope of the invention.Comparative example 9 is silicone content examples outside the scope of the invention.And comparative example the 10, the 11st, the example of manganese content outside the scope of the invention, comparative example the 12, the 13rd, the example of nickel content outside the scope of the invention.And comparative example 14 is chromium content examples outside the scope of the invention, and comparative example 15 is molybdenum content examples outside the scope of the invention.And comparative example 16 is content of vanadium examples outside the scope of the invention, comparative example the 17, the 18th, the example of Ti content outside the scope of the invention, comparative example the 19, the 20th, the example of ree content outside the scope of the invention.

In example 1-12 ,-40 ℃ absorption of weld metal and welding heat affected zone can obtain to have the welding point of outstanding low-temperature flexibility at this for more than 80 joules.On the other hand, comparing in 1,3,5, owing to the scope lower limit of B content less than (1) formula, so the nitrogen fixation of once ferritic inhibition in the weld metal and welding heat affected zone is insufficient, the low-temperature flexibility of weld metal and welding heat affected zone worsens.

In comparative example 2,4, because B content surpasses the range limit of (1) formula, so in weld metal, take place to ftracture and can not take a sample.In addition, in comparative example 6, because B content surpasses the range limit of (1) formula, so generate martensitic phase and the low-temperature flexibility of weld metal and welding heat affected zone is worsened.

In comparative example 7,10,12,17,19, because the content of carbon, manganese, nickel, titanium and rare earth element is respectively less than the lower limit of the scope of the invention, so the low-temperature flexibility of weld metal worsens.

In comparative example 8,13,, can not take a sample so in weld metal, produce cracking owing to carbon, nickel content surpass the upper limit of the present invention respectively.

In comparative example 9,11,14,15,16,18,20, because the content of silicon, manganese, chromium, molybdenum, vanadium, titanium and rare earth element surpasses the upper limit of the scope of the invention respectively, the low-temperature flexibility of weld metal worsens.

And in the present invention, can confirm, can improve by welding heat input 100 kilojoules/centimetre more than the weld metal of the welding point that forms of a large amount of input patterns of fever welding welding steels and the low-temperature flexibility of welding heat affected zone.

Embodiment 2

Carry out welding heat input 100 kilojoules/centimetre more than the submerged-arc welding of a large amount of input pattern of fever and make the welding point of steel plate.

The composition and the thickness of steel plate are as shown in table 5.In welding, used thickness be 6.4 millimeters solid welding wire and contain the solder flux (FS-BT1 that is equivalent to JIS Z 3352) of iron powder and carry out the submerged-arc welding (so-called series connection submerged-arc welding) of bipolar electrode.Its welding condition is as shown in table 6.

Like this, 100 kilojoules/centimetre more than the situation of a large amount of input heat under carry out submerged-arc welding, make its shape welding point as shown in Figure 3 with steel plate D-F.The welding heat input when making each welding point (kilojoule/centimetre) and the composition (weight %) of the weld metal that obtains are as shown in table 7.

In addition, as shown in Figure 4, after 1 millimeter, cut out test film (2 millimeters V notch test sheets of JIS4 number) from weld metal and welding heat affected zone (junction surface) on the surface that reams each welding point respectively, handle and carry out pendulum impact test according to the regulation of JIS Z 2242.Incision site is got the welding heat affected zone (so-called junction surface) that weld metal central portion and molten thread and otch intersect.-40 ℃ absorption can vE _-40(J) be the mean value of three of test films and as shown in table 7.α value in the table 7 is the value of calculating with (3) formula.

Below, instruction card 7.Example 13-24 is the example that welding heat input (kilojoule/centimetre) and weld metal composition (weight %) satisfy the scope of the invention.

Comparative example 21-26 is that B content is at the extraneous example of (1) formula.And comparative example the 27, the 28th, the example of carbon content outside the scope of the invention.Comparative example 29 is silicone content examples outside the scope of the invention.Comparative example the 30, the 31st, the example of manganese content outside the scope of the invention, comparative example the 32, the 33rd, the example of nickel content outside the scope of the invention.And comparative example 34 is chromium content examples outside the scope of the invention, and comparative example 35 is molybdenum content examples outside the scope of the invention.In addition, comparative example 36 is content examples outside the scope of the invention of vanadium and niobium, comparative example the 37, the 38th, the example of Ti content outside the scope of the invention, comparative example the 39, the 40th, the example of ree content outside the scope of the invention.

In example 13-24 ,-40 ℃ absorption of weld metal and welding heat affected zone can have the welding point of outstanding low-temperature flexibility for more than 80 joules in this acquisition.

On the other hand, in comparative example 21,23,25, owing to the lower limit of B content less than (1) formula scope, so the nitrogen of once ferritic inhibition in the weld metal and welding heat affected zone is fixing strong inadequately, the low-temperature flexibility of weld metal and welding heat affected zone worsens.

In comparative example 22,24,, can not take a sample so cracking in weld metal, occurs because B content surpasses the upper limit of (1) formula scope.In addition, in comparative example 26, because B content surpasses the upper limit of (1) formula scope, so generate upper bainite and martensitic phase and the low-temperature flexibility of weld metal and welding heat affected zone is worsened.

In comparative example 28,33,,, cracking can not take a sample so taking place in weld metal owing to carbon, nickel content surpass the upper limit of the scope of the invention respectively.

In comparative example 29,31,34,35,36,38,40, because the content of silicon, manganese, chromium, molybdenum, vanadium, titanium and rare earth element surpasses the upper limit of the scope of the invention, the low-temperature flexibility of weld metal worsens.

And in the present invention, can confirm, can improve by welding heat input 100 kilojoules/centimetre more than the weld metal of the welding point that forms of a large amount of input patterns of fever welding welding steels and the low-temperature flexibility of welding heat affected zone.

Embodiment 3

Carry out welding heat input 100 kilojoules/centimetre more than the electroslag welding of a large amount of input pattern of fever and make the welding point of steel plate.

The composition and the thickness of steel plate are as shown in table 8.In welding, having used thickness is 1.6 millimeters solid welding wire and the solder flux that is equivalent to the FS-FG3 of JIS Z 3353, carries out the electroslag welding of non-consumable electrode type.The shape of its welding point as shown in Figure 5,3 block plates shown in the table of joint 9 are also made welding point under welding condition.

When making welding point, for obtaining intact fusion, on lamella thickness direction make electrode vibration on one side, weld on one side.On side plate, used the band steel that is equivalent to JIS-SN490.

The composition (weight %) of welding heat input when making each welding point (kilojoule/centimetre) and the weld metal that obtained is as shown in table 10.

In addition, as shown in Figure 6, on the maximum position of the weld metal width of each welding point, cut out test film (2 millimeters V notch test sheets of JIS4 number) respectively, handle and carry out pendulum impact test according to the regulation of JIS Z 2242 from weld metal and welding heat affected zone (junction surface).Incision site is got the welding heat affected zone (junction surface) that the weld metal central portion links to each other with molten thread with the surface plate side.-20 ℃ absorption can vE _-20(J) be the mean value of three test films and as shown in table 10.α value in the table 10 is the value of calculating with (3) formula.

Below, instruction card 10.Example 1-12 is the example that welding heat input and weld metal composition (weight %) satisfy the scope of the invention.

Comparative example 1-6 be B content at the extraneous example of (1) formula, and comparative example the 7, the 8th, the example of carbon content outside the scope of the invention.Comparative example 9 is silicone content examples outside the scope of the invention.Comparative example the 10, the 11st, the example of manganese content outside the scope of the invention, comparative example the 12, the 13rd, the example of nickel content outside the scope of the invention.And comparative example 14 is chromium content examples outside the scope of the invention, and comparative example 15 is molybdenum content examples outside the scope of the invention.And comparative example 16 is content of vanadium examples outside the scope of the invention, comparative example the 17, the 18th, the example of Ti content outside the scope of the invention, comparative example the 19, the 20th, the example of ree content outside the scope of the invention.

In example 1-12 ,-20 ℃ absorption of weld metal and welding heat affected zone can obtain to have the welding point of outstanding low-temperature flexibility at this for more than 80 joules.

On the other hand, in comparative example 1,3,5, owing to the lower limit of B content less than (1) formula scope, so the nitrogen of once ferritic inhibition in the weld metal and welding heat affected zone is fixing insufficient, the low-temperature flexibility of weld metal and welding heat affected zone worsens.

In comparative example 2,4, because B content greater than the upper limit of (1) formula scope, so boron is superfluous in weld metal and welding heat affected zone, generates upper bainite and martensite and toughness is worsened.

In comparative example 7,10,12,17,19, because the content of carbon, manganese, nickel, titanium, rare earth element is respectively less than the lower limit of the scope of the invention, so the low-temperature flexibility of weld metal worsens.

In comparative example 8,9,11,13,14,15,16,18,20, because the content of carbon, manganese, chromium, nickel, molybdenum, vanadium, niobium, titanium and rare earth element surpasses the upper limit of the scope of the invention, so the toughness of weld metal worsens.

In the present invention, can improve by welding heat input 100 kilojoules/centimetre more than the weld metal of the welding point that forms of a large amount of input patterns of fever welding welding steels and the low-temperature flexibility of welding heat affected zone.

Table 1

Plating numerals	Thickness of slab (mm)	Steel plate composition (weight %)
													??C	??Si	??Mn	??Ni	??Cr	??Mo	??V	??Nb	??Ti	??B	??N
		??A	??19	??0.07	??0.14	??1.38	??0.02	??0.01	??0.001	??0.001	??0.016	??0.008												??0.0003	??0.005
??B	??40												??0.08	??0.15	??1.44	??0.02	??0.02	??0.001	??0.002	??0.020	??0.009	??0.0002	??0.005
		??C	??60	??0.08	??0.15	??1.48	??0.02	??0.02	??0.001	??0.002	??0.018	??0.009												??0.0002	??0.005

Table 2

The welding wire numbering	Component of weld wire (weight %)
												??C	??Si	??Mn	??Ni	??Cr	??Mo	??V	??Nb	??Ti	??B	??REM
	??1	??0.08	??0.63	??1.73	??3.11	??0.07	??0.01	??0.007	??0.004	??0.11	??0.0052												??0.0024
??2												??0.08	??0.59	??1.65	??2.76	??0.00	??0.01	??0.004	??0.002	??0.11	??0.0062	??0.0027
	??3	??0.02	??0.27	??1.13	??2.21	??0.04	??0.01	??0.002	??0.003	??0.11	??0.0089												??0.0033
??4												??0.11	??1.40	??2.31	??1.86	??0.03	??0.02	??0.004	??0.001	??0.14	??0.0067	??0.0035
	??5	??0.05	??0.73	??1.54	??0.67	??0.03	??0.01	??0.002	??0.005	??0.15	??0.0079												??0.0043
??6												??0.08	??0.64	??1.65	??3.59	??0.04	??0.26	??0.001	??0.006	??0.17	??0.011	??0.0020
	??7	??0.09	??0.47	??1.88	??2.27	??0.51	??0.32	??0.003	??0.002	??0.17	??0.010												??0.0041
??8												??0.06	??0.45	??1.82	??2.08	??0.05	??0.22	??0.10	??0.086	??0.13	??0.0077	??0.0053
	??9	??0.07	??0.53	??1.87	??2.21	??0.03	??0.24	??0.002	??0.005	??0.06	??0.0056												??0.0010
??10												??0.10	??0.64	??1.97	??2.47	??0.03	??0.15	??0.003	??0.003	??0.33	??0.012	??0.0030
	??11	??0.09	??0.63	??1.96	??2.40	??0.05	??0.15	??0.005	??0.002	??0.19	??0.018												??0.0032
??12												??0.08	??0.58	??1.75	??3.19	??0.09	??0.01	??0.007	??0.004	??0.14	??0.0022	??0.0042
	??13	??0.08	??0.59	??1.71	??3.15	??0.05	??0.01	??0.006	??0.003	??0.13	??0.015												??0.0047
??14												??0.08	??0.49	??1.62	??2.22	??0.03	??0.01	??0.006	??0.001	??0.14	??0.0016	??0.0023
	??15	??0.07	??0.55	??1.65	??2.20	??0.02	??0.01	??0.003	??0.004	??0.16	??0.025												??0.0045
??16												??0.07	??0.53	??1.43	??2.09	??0.03	??0.18	??0.002	??0.002	??0.15	??0.0039	??0.0031
	??17	??0.07	??0.44	??1.52	??1.93	??0.03	??0.18	??0.002	??0.004	??0.15	??0.025												??0.0034
??18												??0.02	??0.66	??1.92	??2.54	??0.32	??0.22	??0.063	??0.038	??0.24	??0.0095	??0.0032
	??19	??0.13	??0.40	??1.05	??1.22	??0.02	??0.02	??0.004	??0.005	??0.16	??0.0080												??0.0036
??20												??0.08	??1.83	??1.54	??2.31	??0.05	??0.23	??0.002	??0.004	??0.18	??0.0078	??0.0045
	??21	??0.08	??0.58	??0.75	??3.48	??0.22	??0.46	??0.002	??0.004	??0.18	??0.0084												??0.0052
??22												??0.09	??0.58	??2.66	??1.23	??0.03	??0.13	??0.002	??0.002	??0.16	??0.0066	??0.0047
	??23	??0.09	??0.56	??2.03	??0.55	??0.03	??0.47	??0.001	??0.005	??0.15	??0.0089												??0.0026
??24												??0.08	??0.59	??1.85	??3.95	??0.06	??0.11	??0.001	??0.004	??0.14	??0.0083	??0.0016
	??25	??0.09	??0.77	??1.77	??2.28	??0.69	??0.15	??0.005	??0.001	??0.18	??0.010												??0.0018
??26												??0.06	??0.41	??1.55	??2.17	??0.03	??0.84	??0.005	??0.002	??0.10	??0.006	??0.0027
	??27	??0.06	??0.40	??1.33	??1.90	??0.04	??0.16	??0.15	??0.16	??0.13	??0.0078												??0.0034
??28												??0.08	??0.37	??1.48	??2.21	??0.03	??0.10	??0.002	??0.004	??0.03	??0.0095	??0.0035
	??29	??0.08	??0.46	??1.47	??2.24	??0.03	??0.12	??0.005	??0.005	??0.43	??0.010												??0.0028
??30												??0.08	??0.58	??1.53	??2.63	??0.03	??0.01	??0.005	??0.002	??0.13	??0.0069	??0.0009
	??31	??0.08	??0.55	??1.47	??2.55	??0.04	??0.01	??0.004	??0.005	??0.11	??0.0072												??0.0072

Table 3

Plating numerals	Thickness of slab (mm)	The groove shape	Bevel angle (°)	Butt joint gap (mm)	Welding wire external diameter (mm)	Electric current (A)	Voltage (V)	Amplitude (mm)	Number of times	The welding posture
											A	??19	??V	??20	??5	??1.6	??380	??35	??-	??1	Erect
B	??40	??V	??25	??5	??1.6	??400	??40	??25	??1	Erect
											C	??60	??V	??20	??8	??1.6	??420	??42	??40	??1	Erect

Table 4

	Plating numerals	The welding wire numbering	Welding input heat (kJ/cm)	Weld metal composition (weight %)											The α value	?? VE -40(J)		Remarks
																			??C	??Si	??Mn	??Ni	??Cr	??Mo	??V	??Nb	??Ti	??B	??REM	Weld metal	Welding heat affected zone
				Example 1	??A	??1	??105	??0.09	??0.45	??1.70	??1.85	??0.05	??0.01	??0.003		??0.003	??0.04															??0.0040	??0.0014	??0.0017	??140	??200
Example 2	??B	??2	??215												??0.08			??0.36	??1.66	??2.20	??0.04	??0.01	??0.003	??0.002	??0.03	??0.0038	??0.0022	??0.0022	??130	??170
				Example 3	??C	??2	??490	??0.08	??0.30	??1.56	??2.12	??0.03	??0.01	??0.003		??0.002	??0.03															??0.0030	??0.0018	??0.0028	??95	??135
Example 4	??C	??3	??500												??0.03			??0.15	??1.10	??1.75	??0.03	??0.01	??0.002	??0.002	??0.03	??0.0042	??0.0023	??0.0028	??90	??155
				Example 5	??C	??4	??490	??0.11	??0.70	??2.33	??1.50	??0.03	??0.01	??0.003		??0.002	??0.04															??0.0033	??0.0031	??0.0028	??130	??160
Example 6	??C	??5	??510												??0.05			??0.35	??1.53	??0.52	??0.03	??0.01	??0.002	??0.003	??0.04	??0.0041	??0.0033	??0.0028	??95	??165
				Example 7	??C	??6	??495	??0.08	??0.34	??1.66	??2.88	??0.03	??0.20	??0.002		??0.003	??0.05															??0.0054	??0.0014	??0.0028	??160	??185
Example 8	??C	??7	??515												??0.10			??0.25	??1.89	??1.80	??0.41	??0.25	??0.002	??0.002	??0.05	??0.0050	??0.0035	??0.0028	??135	??140
				Example 9	??C	??8	??485	??0.06	??0.24	??1.85	??1.67	??0.03	??0.17	??0.080		??0.07	??0.03															??0.0039	??0.0041	??0.0028	??130	??150
Example 10	??C	??9	??480												??0.07			??0.26	??1.85	??1.79	??0.03	??0.19	??0.002	??0.003	??0.02	??0.0030	??0.0012	??0.0028	??85	??100
				Example 11	??C	??10	??480	??0.10	??0.33	??1.98	??2.00	??0.03	??0.12	??0.003		??0.002	??0.09															??0.0060	??0.0020	??0.0028	??100	??130
Example 12	??C	??11	??500												??0.09			??0.30	??1.92	??1.90	??0.03	??0.12	??0.003	??0.003	??0.05	??0.0091	??0.0029	??0.0028	??90	??190
				Comparative example 1	??A	??12	??105	??0.08	??0.40	??1.75	??1.92	??0.05	??0.01	??0.003		??0.003	??0.04															??0.0014	??0.0028	??0.0017	??85	??55	The B deficiency
Comparative example 2	??A	??13	??110												??0.08			??0.40	??1.71	??1.90	??0.03	??0.01	??0.003	??0.002	??0.03	??0.012	??0.0029	??0.0017	??-	??-	The B surplus, the weld metal cracking
				Comparative example 3	??B	??14	??210	??0.08	??0.29	??1.60	??1.78	??0.03	??0.01	??0.003		??0.002	??0.04															??0.0008	??0.0020	??0.0022	??70	??40	The B deficiency

Comparative example 4	?B	?15	?215	?0.07	?0.33	?1.64	?1.78	?0.02	?0.01	?0.002	?0.002	?0.04	?0.015	?0.0033	?0.0022	?-	?-	The B surplus, the weld metal cracking
																			Comparative example 5	?C	?16	?495	?0.07	?0.25	?1.42	?1.65	?0.03	?0.15	?0.002	?0.003	?0.04	?0.0020	?0.0021	?0.0028	?85	?50	The B deficiency
Comparative example 6	?C	?17	?480	?0.07	?0.23	?1.55	?1.53	?0.02	?0.14	?0.002	?0.003	?0.04	?0.012	?0.0030	?0.0028	?40	?45	The B surplus
																			Comparative example 7	?C	?18	?485	?0.02	?0.33	?1.95	?2.05	?0.25	?0.18	?0.051	?0.029	?0.06	?0.0045	?0.0025	?0.0028	?30	?45	The C deficiency
Comparative example 8	?C	?19	?480	?0.13	?0.21	?1.03	?0.99	?0.02	?0.01	?0.002	?0.003	?0.04	?0.0039	?0.0028	?0.0028	?-	?-	The C surplus, the weld metal cracking
																			Comparative example 9	?C	?20	?480	?0.08	?0.91	?1.54	?1.85	?0.03	?0.18	?0.003	?0.002	?0.05	?0.0037	?0.0038	?0.0028	?55	?95	The Si surplus
Comparative example 10	?C	?21	?500	?0.09	?0.28	?0.75	?2.78	?0.17	?0.37	?0.002	?0.003	?0.05	?0.0042	?0.0040	?0.0028	?45	?75	The Mn deficiency
																			Comparative example 11	?C	?22	?505	?0.08	?0.29	?2.63	?0.97	?0.02	?0.10	?0.002	?0.003	?0.04	?0.0035	?0.0037	?0.0028	?30	?30	The Mn surplus
Comparative example 12	?C	?23	?510	?0.09	?0.27	?2.03	?0.45	?0.03	?0.38	?0.002	?0.003	?0.04	?0.0045	?0.0020	?0.0028	?65	?90	The Ni deficiency
																			Comparative example 13	?C	?24	?500	?0.08	?0.29	?1.88	?3.18	?0.05	?0.09	?0.002	?0.003	?0.04	?0.0039	?0.0017	?0.0028	?-	?-	The Ni surplus, the weld metal cracking
Comparative example 14	?C	?25	?490	?0.08	?0.37	?1.77	?1.83	?0.55	?0.12	?0.003	?0.002	?0.05	?0.0052	?0.0015	?0.0028	?65	?80	The Cr surplus
																			Comparative example 15	?C	?26	?495	?0.06	?0.22	?1.58	?1.74	?0.03	?0.68	?0.003	?0.003	?0.03	?0.0035	?0.0025	?0.0028	?40	?55	The Mo surplus
Comparative example 16	?C	?27	?510	?0.06	?0.18	?1.32	?1.50	?0.03	?0.13	?0.12	?0.13	?0.03	?0.0040	?0.0027	?0.0028	?25	?40	V, the Nb surplus
																			Comparative example 17	?C	?28	?500	?0.08	?0.20	?1.45	?1.79	?0.02	?0.08	?0.002	?0.003	?0.007	?0.0049	?0.0029	?0.0028	?25	?65	The Ti deficiency
Comparative example 18	?C	?29	?480	?0.08	?0.22	?1.48	?1.78	?0.02	?0.09	?0.003	?0.003	?0.12	?0.0051	?0.0025	?0.0028	?45	?60	The Ti surplus
																			Comparative example 19	?C	?30	?505	?0.08	?0.29	?1.54	?2.10	?0.03	?0.01	?0.003	?0.002	?0.03	?0.0033	?0.0005	?0.0028	?40	?85	The REM deficiency
Comparative example 20	?C	?31	?490	?0.08	?0.27	?1.44	?2.03	?0.03	?0.01	?0.003	?0.003	?0.03	?0.0037	?0.0061	?0.0028	?45	?90	The REM surplus

Table 5

Plating numerals	Thickness of slab (mm)	Steel plate composition (weight %)
													??C	??Si	??Mn	??Ni	??Cr	??Mo	??V	??Nb	??Ti	??B	??N
		??D	??19	??0.07	??0.14	??1.38	??0.02	??0.01	??0.001	??0.001	??0.016	??0.008												??0.0003	??0.0050
??E	??40												??0.08	??0.15	??1.44	??0.02	??0.02	??0.001	??0.002	??0.020	??0.003	??0.0002	??0.0048
		??F	??60	??0.08	??0.15	??1.48	??0.02	??0.02	??0.001	??0.002	??0.018	??0.003												??0.0002	??0.0048

Table 6

Plating numerals	Thickness of slab (mm)	The groove shape	Bevel angle (°)	Weld seam root face (mm)	Electric current (A)		Voltage (V)		Speed (cm/min)	Input heat (kJ/cm)
											The utmost point in advance	The back row utmost point	The utmost point in advance	The back row utmost point
					?D	??19	The Y type	45							?2	?1500	??1000	??34	?40	?42	?130
?E	??40	The Y type	35	?2					?1800	??1400	??34	?46	?28	?269
					?F	??60	The Y type	35							?3	?2300	??1800	??38	?48	?19	?549

Table 7

	Plating numerals	Welding input heat (kJ/cm)	Weld metal composition (weight %)											The α value	VE -40(J)		Remarks
																		??C	?Si	?Mn	?Ni	?Cr	?Mo	?V	?Nb	?Ti	?B	?REM	Weld metal	Welding heat affected zone
			Example 13	?D	?130	?0.07	?0.44	?1.65	?1.88	?0.04	?0.01	?0.004	?0.003		?0.05	?0.0015															?0.0013	?0.0004	?110	?210
Example 14	?E	?269												?0.08			?0.34	?1.68	?2.10	?0.05	?0.01	?0.002	?0.002	?0.04	?0.0033	?0.0024	?0.0013	?140	?180
			Example 15	?F	?549	?0.09	?0.28	?1.59	?2.20	?0.03	?0.01	?0.003	?0.003		?0.03	?0.0032															?0.0019	?0.0022	?95	?145
Example 16	?F	?549												?0.03			?0.14	?1.08	?1.76	?0.02	?0.01	?0.002	?0.002	?0.04	?0.0041	?0.0025	?0.0022	?100	?155
			Example 17	?F	?549	?0.11	?0.75	?2.34	?1.49	?0.03	?0.01	?0.002	?0.003		?0.06	?0.0025															?0.0033	?0.0022	?125	?120
Example 18	?F	?549												?0.06			?0.35	?1.55	?0.55	?0.02	?0.01	?0.003	?0.002	?0.05	?0.0040	?0.0035	?0.0022	?105	?185
			Example 19	?F	?549	?0.06	?0.32	?1.71	?2.89	?0.03	?0.21	?0.002	?0.003		?0.05	?0.0052															?0.0013	?0.0022	?145	?200
Example 20	?F	?549												?0.10			?0.29	?1.91	?1.81	?0.42	?0.26	?0.003	?0.003	?0.04	?0.0049	?0.0032	?0.0022	?130	?165
			Example 21	?F	?549	?0.05	?0.24	?1.82	?1.66	?0.03	?0.18	?0.079	?0.08		?0.02	?0.0029															?0.0044	?0.0022	?140	?145
Example 22	?F	?549												?0.06			?0.27	?1.83	?1.74	?0.02	?0.19	?0.002	?0.003	?0.04	?0.0028	?0.0012	?0.0022	?90	?95
			Example 23	?F	?549	?0.10	?0.32	?1.99	?1.98	?0.03	?0.11	?0.002	?0.003		?0.09	?0.0061															?0.0022	?0.0022	?110	?135
Example 24	?F	?549												?0.09			?0.30	?1.86	?1.89	?0.02	?0.12	?0.003	?0.003	?0.06	?0.0092	?0.0031	?0.0022	?85	?190
			Comparative example 21	?D	?130	?0.07	?0.41	?1.77	?1.91	?0.04	?0.01	?0.003	?0.002		?0.03	?0.0002															?0.0032	?0.0004	?100	?55	The B deficiency
Comparative example 22	?D	?269												?0.09			?0.40	?1.72	?1.90	?0.03	?0.01	?0.002	?0.002	?0.02	?0.013	?0.0028	?0.0004	?-	?-	The B surplus, the weld metal cracking
			Comparative example 23	?E	?269	?0.08	?0.28	?1.60	?1.81	?0.02	?0.01	?0.003	?0.003		?0.04	?0.0008															?0.0019	?0.0013	?75	?40	The B deficiency

Comparative example 24	?E	?549	?0.08	?0.32	?1.64	?1.79	?0.02	?0.01	?0.002	?0.002	?0.04	?0.015	?0.0033	?0.0013	?-	?-	The B surplus, the weld metal cracking
																		Comparative example 25	?F	?549	?0.07	?0.26	?1.44	?1.64	?0.03	?0.16	?0.003	?0.002	?0.05	?0.0018	?0.0022	?0.0013	?85	?45	The B deficiency
Comparative example 26	?F	?549	?0.07	?0.22	?1.52	?1.52	?0.03	?0.15	?0.002	?0.003	?0.03	?0.013	?0.0032	?0.0022	?50	?55	The B surplus
																		Comparative example 27	?F	?549	?0.02	?0.31	?1.96	?2.02	?0.26	?0.17	?0.051	?0.031	?0.06	?0.0042	?0.0024	?0.0022	?25	?60	The C deficiency
Comparative example 28	?F	?549	?0.13	?0.20	?1.01	?0.98	?0.02	?0.01	?0.002	?0.003	?0.04	?0.0038	?0.0027	?0.0022	?-	?-	The C surplus, the weld metal cracking
																		Comparative example 29	?F	?549	?0.08	?0.89	?1.52	?1.84	?0.03	?0.18	?0.002	?0.002	?0.03	?0.0035	?0.0038	?0.0022	?50	?105	The Si surplus
Comparative example 30	?F	?549	?0.08	?0.27	?0.78	?2.77	?0.18	?0.35	?0.003	?0.002	?0.05	?0.0044	?0.0041	?0.0022	?40	?80	The Mn deficiency
																		Comparative example 31	?F	?549	?0.08	?0.25	?2.62	?0.98	?0.03	?0.10	?0.002	?0.002	?0.03	?0.0036	?0.0036	?0.0022	?35	?75	The Mn surplus
Comparative example 32	?F	?549	?0.09	?0.24	?2.02	?0.44	?0.02	?0.36	?0.002	?0.002	?0.05	?0.0042	?0.0022	?0.0022	?30	?85	The Ni deficiency
																		Comparative example 33	?F	?549	?0.08	?0.26	?1.87	?3.21	?0.04	?0.08	?0.003	?0.003	?0.05	?0.0036	?0.0018	?0.0022	?-	?-	The Ni surplus, the weld metal cracking
Comparative example 34	?F	?549	?0.08	?0.39	?1.75	?1.85	?0.56	?0.13	?0.003	?0.002	?0.04	?0.0055	?0.0016	?0.0022	?55	?80	The Cr surplus
																		Comparative example 35	?F	?549	?0.07	?0.24	?1.56	?1.74	?0.02	?0.69	?0.002	?0.002	?0.03	?0.0034	?0.0026	?0.0022	?35	?75	The Mo surplus
Comparative example 36	?F	?549	?0.05	?0.19	?1.31	?1.51	?0.03	?0.12	?0.15	?0.12	?0.02	?0.0039	?0.0027	?0.0022	?25	?65	V, the Nb surplus
																		Comparative example 37	?F	?549	?0.08	?0.19	?1.44	?1.77	?0.02	?0.07	?0.002	?0.003	?0.006	?0.0046	?0.0029	?0.0022	?25	?80	The Ti deficiency
Comparative example 38	?F	?549	?0.08	?0.21	?1.49	?1.79	?0.03	?0.08	?0.003	?0.003	?0.13	?0.0052	?0.0024	?0.0022	?45	?60	The Ti surplus
																		Comparative example 39	?F	?549	?0.08	?0.26	?1.53	?2.12	?0.03	?0.01	?0.002	?0.002	?0.03	?0.0035	?0.0006	?0.0022	?40	?90	The REM deficiency
Comparative example 40	?F	?549	?0.08	?0.27	?1.42	?2.01	?0.02	?0.01	?0.003	?0.002	?0.03	?0.0036	?0.0060	?0.0022	?45	?95	The REM surplus

Table 8

Numbering	Thickness of slab (mm)	Steel plate composition (weight %)
													??C	??Si	??Mn	??Ni	??Cr	??Mo	??V	??Nb	??Ti	??B	??N
		??G	??30	??0.07	??0.14	??1.37	??0.02	??0.01	??0.001	??0.001	??0.014	??0.009												??0.0003	??0.0047
??H	??45												??0.08	??0.15	??1.42	??0.02	??0.02	??0.001	??0.002	??0.018	??0.010	??0.0002	??0.0044
		??I	??60	??0.08	??0.15	??1.48	??0.02	??0.02	??0.001	??0.002	??0.018	??0.009												??0.0002	??0.0048

Table 9

The joint numbering	Dividing plate		Surface plate		Electric current (A)	Voltage (V)	Amplitude (mm)	Speed (cm/min)	Input heat (kJ/cm)
										Steel plate	Thickness of slab (mm)	Steel plate	Thickness of slab (mm)
	?a	?G	?30	?G										?45	?380	?50	?10	?2.6	?425
?b					?H	?45	?H	?60	?380	?52	?20	?1.7	?690
	?c	?I	?60	?I										?60	?380	?53	?33	?1.3	?943

Table 10

Distinguish	Numbering	The joint numbering	Welding input (kJ/cm)	Weld metal composition (weight %)											The α value	VE-20(J)		Remarks
																			?C	?Si	?Mn	?Ni	?Cr	?Mo	?V	?Nb	?Ti	?B	?REM	Weld metal	Welding heat affected zone
				Patent is asked for protection scope				?0.03- ?0.12	?0.10- ?0.80	?0.80 ?2.50	?0.50- ?3.00	0.50 below	0.50 below	0.10 below		0.10 below	?0.01- ?0.10	?α*- ?0.010															?0.0010 ?0.0050		?＞80	?＞80
Embodiment	?1	?a	?425												?0.08				?0.38	?1.59	?0.89	?0.03	?0.24	?0.003	?0.007	?0.04	?0.0033	?0.0024	?0.0019	?132	?198
				?2	?b	?690	?0.08	?0.36	?1.58	?0.85	?0.04	?0.22	?0.003	?0.006		?0.04	?0.0032	?0.0028															?0.0025	?123	?187
	?3	?c	?943												?0.09				?0.25	?1.59	?1.90	?0.03	?0.26	?0.002	?0.005	?0.03	?0.0043	?0.0032	?0.0029	?85	?165
				?4	?c	?943	?0.03	?0.12	?0.89	?0.82	?0.02	?0.24	?0.002	?0.006		?0.04	?0.0042	?0.0033															?0.0029	?93	?197
	?5	?c	?943												?0.11				?0.76	?2.37	?0.83	?0.02	?0.02	?0.003	?0.007	?0.03	?0.0035	?0.0032	?0.0029	?105	?143
				?6	?c	?943	?0.05	?0.34	?1.53	?0.58	?0.03	?0.29	?0.002	?0.006		?0.03	?0.0042	?0.0034															?0.0029	?99	?201
	?7	?c	?943												?0.06				?0.32	?1.66	?2.77	?0.02	?0.24	?0.002	?0.008	?0.04	?0.0056	?0.0028	?0.0029	?113	?174
				?8	?c	?943	?0.03	?0.30	?1.92	?0.97	?0.45	?0.25	?0.002	?0.007		?0.03	?0.0064	?0.0026															?0.0029	?126	?184
	?9	?c	?943												?0.05				?0.26	?1.78	?1.05	?0.03	?0.29	?0.077	?0.07	?0.03	?0.0052	?0.0044	?0.0029	?107	?196
				?10	?c	?943	?0.07	?0.26	?1.79	?1.03	?0.02	?0.25	?0.002	?0.008		?0.02	?0.0044	?0.0017															?0.0029	?94	?182
	?11	?c	?943												?0.11				?0.39	?1.88	?0.98	?0.03	?0.02	?0.001	?0.009	?0.08	?0.0077	?0.0025	?0.0029	?101	?171
				?12	?c	?943	?0.09	?0.28	?1.87	?1.12	?0.03	?0.27	?0.002	?0.006		?0.06	?0.0089	?0.0033															?0.0029	?83	?210
		?1	?A												?425				?0.07	?0.40	?1.75	?1.02	?0.02	?0.22	?0.002	?0.007	?0.03	?0.0013	?0.0024	?0.0019	?38	?37					The B deficiency

	??2	??A	??425	??0.08	??0.39	??1.72	??0.97	??0.02	??0.23	??0.003	??0.008	??0.03	??0.012	??0.0031	??0.0019	??45	??76	The B surplus
																			??3	??B	??690	??0.09	??0.27	??1.55	??1.11	??0.03	??0.26	??0.001	??0.008	??0.04	??0.0019	??0.0028	??0.0025	??44	??40	The B deficiency
	??4	??B	??690	??0.08	??0.28	??1.68	??1.02	??0.02	??0.25	??0.002	??0.006	??0.04	??0.014	??0.0029	??0.0025	??52	??60	The B surplus
																			??5	??C	??943	??0.07	??0.26	??1.45	??0.97	??0.03	??0.38	??0.001	??0.007	??0.03	??0.0021	??0.0027	??0.0029	??39	??41	The B deficiency
	??6	??C	??943	??0.07	??0.24	??1.47	??0.99	??0.02	??0.33	??0.002	??0.007	??0.03	??0.015	??0.0027	??0.0029	??55	??59	The B surplus
																			??7	??C	??943	??0.02	??0.28	??1.88	??1.23	??0.24	??0.28	??0.048	??0.034	??0.04	??0.0045	??0.0026	??0.0029	??24	??155	The C deficiency
	??8	??C	??943	??0.14	??0.22	??1.05	??0.87	??0.03	??0.01	??0.001	??0.008	??0.04	??0.0043	??0.0029	??0.0029	??31	??105	The C surplus
																			??9	??C	??943	??0.09	??0.88	??1.48	??1.10	??0.02	??0.33	??0.002	??0.009	??0.03	??0.0051	??0.0034	??0.0029	??44	??167	The Si surplus
	??10	??C	??943	??0.08	??0.25	??0.68	??1.27	??0.20	??0.32	??0.003	??0.008	??0.03	??0.0055	??0.0039	??0.0029	??31	??188	The Mn deficiency
																			??11	??C	??943	??0.07	??0.25	??2.65	??0.99	??0.04	??0.28	??0.002	??0.007	??0.03	??0.0054	??0.0044	??0.0029	??42	??201	The Mn surplus
	??12	??C	??943	??0.08	??0.24	??1.95	??0.42	??0.02	??0.29	??0.001	??0.008	??0.03	??0.0060	??0.0040	??0.0029	??71	??166	The Ni deficiency
																			??13	??C	??943	??0.07	??0.25	??1.88	??3.22	??0.02	??0.19	??0.002	??0.008	??0.04	??0.0048	??0.0022	??0.0029	??63	??169	The Ni surplus
	??14	??C	??943	??0.08	??0.38	??1.80	??0.98	??0.61	??0.22	??0.002	??0.007	??0.04	??0.0049	??0.0026	??0.0029	??54	??156	The Cr surplus
																			??15	??C	??943	??0.07	??0.23	??1.67	??1.00	??0.03	??0.61	??0.002	??0.008	??0.04	??0.0040	??0.0025	??0.0029	??68	??123	The Mo surplus
	??16	??C	??943	??0.06	??0.20	??1.38	??0.94	??0.03	??0.29	??0.14	??0.13	??0.03	??0.0056	??0.0025	??0.0029	??48	??153	V, the Nb surplus
																			??17	??C	??943	??0.08	??0.20	??1.46	??0.93	??0.02	??0.24	??0.002	??0.008	??0.006	??0.0061	??0.0031	??0.0029	??29	??99	The Ti deficiency
	??18	??C	??943	??0.09	??0.22	??1.45	??0.88	??0.02	??0.25	??0.002	??0.007	??0.14	??0.0068	??0.0028	??0.0029	??52	??129	The Ti surplus
																			??19	??C	??943	??0.07	??0.24	??1.49	??0.91	??0.02	??0.27	??0.001	??0.006	??0.03	??0.0047	??0.0007	??0.0029	??57	??190	The REM deficiency
	??20	??C	??943	??0.07	??0.28	??1.44	??1.01	??0.03	??0.27	??0.002	??0.008	??0.03	??0.0049	??0.0062	??0.0029	??42	??98	The REM surplus

*) α=0.003 * { 0.23 * ln (Q)-1.9} (Q: welding input heat (kJ/cm))

Claims (10)

1, welding point, it be by welding heat input 100 kilojoules/centimetre more than the welding point that forms of a large amount of input patterns of fever welding welding steels, it is characterized in that, the weld metal of this welding point has such composition: C 0.03 weight %-0.12 weight %, Si 0.10 weight %-0.80 weight %, Mn 0.80 weight %-2.50 weight %, Ni 0.50 weight %-3.00 weight %, below the Cr 0.50 weight %, below the Mo 0.50 weight %, Ti 0.01 weight %-0.10 weight %, rare earth element 0.0010 weight %-0.0050 weight %, and the content of B (mass percent) satisfies following formula (1), and surplus is iron and unavoidable impurities

f(Q)≤[B]≤0.01??????????????(1)

Q: welding heat input (kJ/cm)

F (Q): the function of Q

The content of [B]: B (mass percent).

2, welding point as claimed in claim 1 is characterized in that, the weld metal of this welding point also contains V and the Nb below the 0.10 weight % below the 0.10 weight % except mentioned component.

3, welding point as claimed in claim 1 or 2 is characterized in that, this imports the pattern of fever welding in a large number is to import the pattern of fever electrogas arc welding in a large number, and f (Q) is the function according to following formula (2),

f(Q)＝0.003×{0.23×ln(Q)-0.5}????(2)

Ln (Q): the natural logrithm of Q.

4, welding point as claimed in claim 1 or 2 is characterized in that, this imports the pattern of fever welding in a large number is to import pattern of fever submerged-arc welding in a large number, and f (Q) is the function according to following formula (3),

f(Q)＝0.003×{0.42×ln(Q)-1.9}????????(3)。

5, welding point as claimed in claim 1 or 2 is characterized in that, this imports the pattern of fever welding in a large number is to import the pattern of fever electroslag welding in a large number, and f (Q) is the function according to following formula (3),

f(Q)＝0.003×{0.42×ln(Q)-1.9}????????(3)。

6, welding method, it be by welding heat input 100 kilojoules/centimetre more than the welding method that forms of a large amount of input patterns of fever welding welding steels, it is characterized in that, the weld metal of this welding point has such composition: C 0.03 weight %-0.12 weight %, Si 0.10 weight %-0.80 weight %, Mn 0.80 weight %-2.50 weight %, Ni 0.50 weight %-3.00 weight %, below the Cr 0.50 weight %, below the Mo 0.50 weight %, Ti 0.01 weight %-0.10 weight %, rare earth element 0.0010 weight %-0.0050 weight %, and the content of B (mass percent) satisfies following formula (1), and surplus is iron and unavoidable impurities

f(Q)≤[B]≤0.01?????????????(1)

Q: welding heat input (kJ/cm)

F (Q): the function of Q

The content of [B]: B (mass percent).

7, welding method as claimed in claim 6 is characterized in that, the weld metal of this welding point also contains V and the Nb below the 0.10 weight % below the 0.10 weight % except mentioned component.

As claim 6 or 7 described welding methods, it is characterized in that 8, this imports the pattern of fever welding in a large number is to import the pattern of fever electrogas arc welding in a large number, f (Q) is the function according to following formula (2),

f(Q)＝0.003×{0.23×ln(Q)-0.5}???????(2)

Ln (Q): the natural logrithm of Q.

As claim 6 or 7 described welding methods, it is characterized in that 9, this imports the pattern of fever welding in a large number is to import pattern of fever submerged-arc welding in a large number, f (Q) is the function according to following formula (3),

f(Q)＝0.003×{0.42×ln(Q)-1.9}???????(3)。

As claim 6 or 7 described welding methods, it is characterized in that 10, this imports the pattern of fever welding in a large number is to import the pattern of fever electroslag welding in a large number, f (Q) is the function according to following formula (3),

f(Q)＝0.003×{0.42×ln(Q)-1.9}???????(3)。

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