CN104907726A

CN104907726A - Solid wire for gas metal arc welding

Info

Publication number: CN104907726A
Application number: CN201410776598.3A
Authority: CN
Inventors: 谷口元一; 山下贤
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 2014-03-10
Filing date: 2014-12-15
Publication date: 2015-09-16
Anticipated expiration: 2034-12-15
Also published as: KR101688310B1; KR20150105925A; CN104907726B; JP2015167995A; JP6255284B2

Abstract

The invention provides a solid wire for gas metal arc welding. The weld metal with excellent tensile strength, tenacity and drop hammer performances can be obtained through the solid wire. The solid wire is characterized by containing C:0.010-0.100 mass%, Si: 0.20-1. 00 mass%, Mn: 1.00-2.00 mass%, P: less than 0.025 mass%, S: less than 0.025 mass%, Cu: less than 0.35 mass%, Ni: 4.00-5. 00 mass%, Mo: 0.10-0. 50 mass%, Ti: 0.025-0.075 mass%, and balance of Fe and unavoidable impurities.

Description

Gas metal arc welding flux-cored wire

Technical field

The present invention relates to the gas metal arc welding flux-cored wire of the welding for Mn-Mo-Ni steel, Ni steel.

Background technology

In the past, for the Mn-Mo-Ni steel that the pressure vessel or reservoir vessel etc. in energy plant or chemical plant, energy source raw material bunkerage is used, Ni steel, mainly gas metal arc welding was carried out.And, disclose the various gas metal arc welding flux-cored wires for carrying out such gas metal arc welding.

Such as; patent document 1 discloses a kind of gas shield pulsed arc welding method; it is characterized in that, in pulse arc welding, weld under being the condition of the scope of Ip≤900A Ib >=30A 1.2≤MR≤1.5 at peak point current Ip, background current Ib, melting velocity rate MR.

In addition; as the welding wire for this gas shield pulsed arc welding method; disclose a kind of gas shielded arc welding welding wire; the chemical composition of welding wire is relative to welding wire gross weight; in % by weight; containing C:0.02 ~ 0.20%, Si:0.2 ~ 2.0%, Mn:0.2 ~ 3.0%, below P:0.05%, below S:0.05%, below Cu:1.5%, inevitable composition is less than 0.1%, and surplus is made up of Fe in fact.

In addition; disclose a kind of gas shielded arc welding welding wire; the chemical composition of welding wire is relative to welding wire gross weight; in % by weight; also containing at least one element be selected from Ni:0.10 ~ 5.00%, Cr:0.10 ~ 3.00%, Mo:0.05 ~ 2.00%, Ti:0.02 ~ 0.50%, B:0.0010 ~ 0.0300%; inevitable composition is less than 0.1%, and surplus is made up of Fe in fact.

This gas shielded arc welding welding wire is the MAG flux-cored wire used for welding of the Ni containing 0.10 ~ 5.00 quality %, in the best region of the impulsive condition when welding, can take into account the engineering properties of weld job and motlten metal.

In addition, such as patent document 2 discloses a kind of extra-high tension steel gas shielded arc welding welding wire, it is characterized in that, in mass %, containing C:0.020 ~ 0.060%, Si:0.20 ~ 0.50%, Mn:1.50 ~ 2.50%, Ni:2.90 ~ 3.50%, Cr:0.7 ~ 1.5%, Mo:0.30 ~ 1.00%, Ti:0.010 ~ 0.050%, Al:0.020 ~ 0.080%, using the P as impurity, S, N, O, V, Nb is reduced to below P:0.007%, below S:0.007%, below N:0.007%, below O:0.007%, below V:0.005%, below Nb:0.003%, surplus is made up of Fe and inevitable impurity.

This extra-high tension steel gas shielded arc welding welding wire is the MAG flux-cored wire used for welding of the Ni containing 2.90 ~ 3.50 quality %, by making containing appropriate Ti and Al in welding wire, thus can take into account welding point tensile strength and toughness.

Prior art document

Patent document

Patent document 1: Japanese Unexamined Patent Publication 2000-225465 publication

Patent document 2: Japanese Unexamined Patent Publication 2001-1181 publication

Summary of the invention

Invent problem to be solved

But, in existing technology, there is following problem.About patent document 1; the welding of the steel of thick-wall and large-diameter can implement post weld heat treatment (afterwards usually; suitably referred to as PWHT (Post Weld Heat Treatment)), but in patent document 1, do not mention the engineering properties after the PWHT of deposited metal.In addition, about the toughness of deposited metal, vE0 DEG C or vE-20 DEG C >=/47J are set to good performance, but are insufficient threshold value for the requirement performance of reality.

About patent document 2, although the welding of the steel of thick-wall and large-diameter can implement PWHT usually, the engineering properties after the PWHT of deposited metal do not mentioned by patent document 2.

Like this, as the characteristic ameliorative way of the deposited metal that gas metal arc welding brings, the various alloying components being representative can be adopted with Ni to the adjustment of the interpolation in welding wire, welding condition.But, do not demonstrate the opinion about following technology: even if after the PWHT that can implement when the welding of the steel plate of the major diameter wall thickness as practical operation object, still ensure the technology of excellent engineering properties.

In addition, do not demonstrate the opinion about following technology: even if provide at the execution conditions paying attention to welding procedure efficiency, even if under the welding condition under particularly comprising the various welding postures of upward welding in the vertical position posture and when large-line energy, still there is the technology of the deposited metal of excellent mechanical property.

Therefore, existingly apply for a patent any opinion that group forms and cannot solve under the condition of various welding posture, heat input scope, even and if still make tensile strength characteristic, toughness and characteristic of dropping hammer be good problem after PWHT.

In addition, with regard to existing welding material, for the various pressure vessels in energy plant or chemical plant be suitable for Mn-Mo-Ni steel, Ni steel welding position, exist and large-line energy cannot be made to construct and the tensile strength characteristic of deposited metal after PWHT, toughness and characteristic of dropping hammer are good problem.

Therefore, problem of the present invention is, provides the gas metal arc welding flux-cored wire of the deposited metal that can obtain tensile strength characteristic, toughness and the excellent that drops hammer.

For solving the method for problem

Present inventor has performed further investigation, found that following item.

Gas metal arc welding involved by the application (afterwards, suitably referred to as the GMAW) Ni of flux-cored wire containing 4.00 ~ 5.00 quality % in welding wire.Even if as large-line energy construction and after PWHT, still make the tensile strength characteristic of this deposited metal, toughness and characteristic of dropping hammer be good method, inventor obtains " realizing the interpolation of the alloying element of solution strengthening and precipitation strength " simultaneously and the design of " microstructures Control of the field trash of separating out in process of setting when applying flexibly welding ".

The position being suitable for GMAW flux-cored wire comprises: in Machinery Design, implements the situation of PWHT according to the thickness of slab of application site, stress distribution; Do not implement the situation of PWHT.Therefore, for this deposited metal, no matter PHWT presence or absence and need tensile strength, toughness and characteristic of dropping hammer are well.

Usually, the GMAW flux-cored wire of being correlated with by the application and the microscopic structure of the deposited metal formed is bainite main body, tissue is replied because of the enforcement of PHWT, and its toughness of one side and characteristic of dropping hammer improve and the tendency of tensile strength reduction is stronger on the other hand.In addition, the deposited metal formed with flux-cored wire by GMAW, when carrying out welding procedure under large-line energy condition, the remarkable coarsening of its microscopic structure, tensile strength, toughness and characteristic of dropping hammer all reduce.

Therefore, wish to obtain following deposited metal: even if such as paying attention to efficiency of construction, in upward welding in the vertical position posture and carry out welding procedure under large-line energy condition when, still can demonstrate excellent toughness under the state after only welding and characteristic of dropping hammer, there is the deposited metal of the tensile strength of regulation under state after PWHT.And the present inventor finds the chemical composition of this GMAW flux-cored wire.

For the improvement of tensile strength, the precipitation strength brought is separated out in (1) dispersion of carbonitride caused by PWHT, the miniaturization of solution strengthening that (2) add up to element to bring to the solid solution in matrix or (3) old γ particle diameter is effective.In order to realize (1), the alloying element that interpolation Cr, Nb, V etc. form carbide in crystal grain boundary or crystal grain is effective, but the interpolation of these alloying elements makes the toughness of deposited metal and characteristic of dropping hammer reduces, therefore not preferred.Therefore, in this application, be conceived to realize (1) and (2) and the Mo less to Toughness simultaneously.On the other hand, in order to realize (3), be conceived to form nitride in the process of setting when welding, being suppressed the Ti of the coarsening of γ grain by its pinning effect.

In addition, in order to improve toughness and drop hammer characteristic, the high malleableize of (4) matrix, the miniaturization of (5) old γ particle diameter or the miniaturization of (6) lath of bainite are effective.In order to realize (4), it is effective for adding Ni, and becomes the Basic Design of the MIG flux-cored wire used for welding involved by the application.In order to realize (5), as mentioned above, the interpolation of Ti is conceived to.In addition, in order to realize (6), add making A1 transformation temperature and bainitic transformation start temperature to reduce, be effective by the alloying element of lath of bainite miniaturization, in the application, be conceived to Mn and Ni.

In order to solve above-mentioned problem, in the present invention, take following technological means.

The feature of gas metal arc welding flux-cored wire of the present invention is; containing C:0.010 ~ 0.100 quality %, Si:0.20 ~ 1.00 quality %, Mn:1.00 ~ 2.00 quality %, below P:0.025 quality %, S:0.025 below quality %, below Cu:0.35 quality %, Ni:4.00 ~ 5.00 quality %, Mo:0.10 ~ 0.50 quality %, Ti:0.025 ~ 0.075 quality %, surplus is made up of Fe and inevitable impurity.

According to above-mentioned formation; gas metal arc welding is (following with flux-cored wire; suitably be called flux-cored wire or be only called welding wire) by specifying the content of C, Si, Mn, P, S, Cu, Ni, Mo, Ti, thus the intensity of deposited metal, toughness and characteristic of dropping hammer become good.

Gas metal arc welding flux-cored wire of the present invention is preferably: containing C:0.010 ~ 0.050 quality %, Si:0.20 ~ 0.50 quality %, Mn:1.10 ~ 1.40 quality %, below P:0.010 quality %, S:0.010 below quality %, below Cu:0.35 quality %, Ni:4.00 ~ 4.50 quality %, Mo:0.10 ~ 0.30 quality %, Ti:0.050 ~ 0.075 quality %, and surplus is made up of Fe and inevitable impurity.

According to above-mentioned formation, by the composition of flux-cored wire is set to preferred regulation, thus the intensity of deposited metal, toughness and characteristic of dropping hammer become more good.

Invention effect

For gas metal arc welding flux-cored wire of the present invention; even if it can provide under large-line energy execution conditions and after PWHT; still make the characteristic of deposited metal improve, tensile strength characteristic, toughness and the equal excellent deposited metal of characteristic of dropping hammer tremendously.

Accompanying drawing explanation

Fig. 1 is for representing the profile of the bevel shape of the breadboard used in the evaluation of embodiment.

Fig. 2 is the profile representing the tensile test at room temperature sheet of embodiment and the collection position of Charpy-type test sheet.

Fig. 3 is the profile of the collection position of the drop weight test sheet representing embodiment.

Detailed description of the invention

Below, embodiments of the present invention are described in detail.The flux-cored wire that flux-cored wire of the present invention uses for gas metal arc welding; containing C:0.010 ~ 0.100 quality %, Si:0.20 ~ 1.00 quality %, Mn:1.00 ~ 2.00 quality %, below P:0.025 quality %, S:0.025 below quality %, below Cu:0.35 quality %, Ni:4.00 ~ 5.00 quality %, Mo:0.10 ~ 0.50 quality %, Ti:0.025 ~ 0.075 quality %, surplus is made up of Fe and inevitable impurity.

In addition, flux-cored wire of the present invention is preferably, containing C:0.010 ~ 0.050 quality %, Si:0.20 ~ 0.50 quality %, Mn:1.10 ~ 1.40 quality %, below P:0.010 quality %, S:0.010 below quality %, below Cu:0.35 quality %, Ni:4.00 ~ 4.50 quality %, Mo:0.10 ~ 0.30 quality %, Ti:0.050 ~ 0.075 quality %, surplus is made up of Fe and inevitable impurity.

Below, limit reason to the composition of flux-cored wire to be described.

<C:0.010 ~ 0.100 quality %>

C brings considerable influence to the amount of precipitation of the carbide in deposited metal.If the C content in flux-cored wire is less than 0.010 quality %, then the C content step-down in deposited metal, the amount of precipitation of carbide becomes insufficient, cannot obtain the intensity specified.On the other hand, if the C content in flux-cored wire is more than 0.100 quality %, then the C content in deposited metal becomes too high, and quenching degree improves, and Carbide Precipitation amount increases in addition, improves the intensity of deposited metal, and toughness and characteristic of dropping hammer reduce.Therefore, the C content of flux-cored wire entirety is set to 0.010 ~ 0.100 quality %.From the viewpoint of the intensity improving deposited metal further, C content is preferably more than 0.015 quality %, is more preferably more than 0.020 quality %.In addition, from the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, C content is preferably below 0.050 quality %, is more preferably below 0.040 quality %.

<Si:0.20 ~ 1.00 quality %>

Si, while the intensity improving deposited metal, by deposited metal deoxidation, purifying, makes toughness improve.If the Si content in flux-cored wire is less than 0.20 quality %, then the Si content step-down in deposited metal, its intensity reduces, and the oxygen amount in addition in deposited metal increases, and forms thick oxide, and therefore toughness and characteristic of dropping hammer reduce.On the other hand, if the Si content in flux-cored wire is more than 1.00 quality %, then the interpolation of Si becomes superfluous, and the intensity of deposited metal significantly uprises, and toughness and characteristic of dropping hammer reduce.Therefore, the Si content of flux-cored wire entirety is set to 0.20 ~ 1.00 quality %.From the viewpoint of improving intensity, the toughness of deposited metal and characteristic of dropping hammer further, Si content is preferably more than 0.25 quality %, is more preferably more than 0.30 quality %.In addition, from the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Si content is preferably below 0.50 quality %, is more preferably below 0.45 quality %.

<Mi:1.00 ~ 2.00 quality %>

Mn makes A1 transformation temperature and bainitic transformation start temperature reduction, makes bainite structure miniaturization, makes the toughness of deposited metal and characteristic raising of dropping hammer.In addition, Mn and Si similarly, by deposited metal deoxidation, purifying, makes its toughness improve.If the Mn content in flux-cored wire is less than 1.00 quality %, then cannot obtain these effects.On the other hand, if the Mn content in flux-cored wire is more than 2.00 quality %, then the interpolation of Mn becomes superfluous, and the intensity of deposited metal significantly uprises, and toughness and characteristic of dropping hammer reduce.Therefore, the Mn content of flux-cored wire entirety is set to 1.00 ~ 2.00 quality %.From the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Mn content is preferably more than 1.10 quality %, is more preferably more than 1.20 quality %.In addition, from the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Mn content is preferably below 1.40 quality %, is more preferably below 1.30 quality %.

Below <P:0.025 quality %, S:0.025 below quality % >

If the content of P and S is respectively more than 0.025 quality %, then make deposited metal brittle, make its toughness and characteristic reduction of dropping hammer.Therefore, the P content of flux-cored wire entirety and S content are all set to below 0.025 quality %.From the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, P content and S content are all preferably below 0.010 quality %, are more preferably below 0.008 quality %.It should be noted that, although lower limit does not have special provision, preferably not containing P and S, be preferably 0 quality %.But owing to being inevitably mixed into P and S, therefore 0.001 quality % becomes lower limit in fact.

Below <Cu:0.35 quality % >

Cu to be derived from welding wire contained Cu and in order to improve welding time welding wire feeding and by method platings such as plating in the Cu of welding wire surface.If the Cu content in flux-cored wire is more than 0.35 quality %, then the Cu content in deposited metal also increases, and its toughness and characteristic of dropping hammer reduce.Therefore, the Cu content of flux-cored wire entirety is set to below 0.35 quality %.From the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Cu content is preferably below 0.25 quality %, is more preferably below 0.20 quality %.It should be noted that, although lower limit does not have special provision, also can not contain Cu, lower limit can be 0 quality %.But owing to being inevitably mixed into Cu, therefore 0.01 quality % becomes lower limit in fact.

<Ni:4.00 ~ 5.00 quality %>

The basis of the welding welding wire of Ni involved by the application, makes A1 transformation temperature and bainitic transformation start temperature and declines, make bainite structure miniaturization, and the toughness of matrix is improved, and makes the toughness of deposited metal and characteristic raising of dropping hammer.If the Ni content in flux-cored wire is less than 4.00 quality %, then cannot fully obtain these effects.On the other hand, if the Ni content in flux-cored wire is more than 5.00 quality %, then the intensity of deposited metal significantly uprises, and toughness and characteristic of dropping hammer reduce.Therefore, the Ni content of flux-cored wire entirety is set to 4.00 ~ 5.00 quality %.From the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Ni content is preferably more than 4.20 quality %, is more preferably more than 4.30 quality %.In addition, from the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Ni content is preferably below 4.50 quality %, is more preferably below 4.40 quality %.

<Mo:0.10 ~ 0.50 quality %>

Mo forms carbide when PWHT, and is solid-solution in matrix, and the intensity of deposited metal is improved.If the Mo content in flux-cored wire is less than 0.10 quality %, then cannot obtain the tensile strength specified.On the other hand, if the Mo content in flux-cored wire is more than 0.50 quality %, then Carbide Precipitation amount and excessively increasing to the solid solution capacity in matrix, the intensity of deposited metal significantly uprises, and toughness and characteristic of dropping hammer reduce.Therefore, the Mo content of flux-cored wire entirety is set to 0.10 ~ 0.50 quality %.From the viewpoint of the intensity improving deposited metal further, Mo content is preferably more than 0.15 quality %, is more preferably more than 0.20 quality %.In addition, from the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Mo content is preferably below 0.30 quality %, is more preferably below 0.25 quality %.

<Ti:0.025 ~ 0.075 quality %>

Forming TiN in the process of setting of Ti when welding, being suppressed the coarsening of γ grain by its pinning effect, making the miniaturization of old γ particle diameter.Thus, the intensity of deposited metal, toughness and characteristic of dropping hammer is made to improve.If the Ti content in flux-cored wire is less than 0.025 quality %, then cannot fully obtain these effects.On the other hand, if the Ti content in flux-cored wire is more than 0.075 quality %, then the intensity of deposited metal significantly uprises, and toughness and characteristic of dropping hammer reduce.Therefore, the Ti content of flux-cored wire entirety is set to 0.025 ~ 0.075 quality %.From the viewpoint of improving intensity, the toughness of deposited metal and characteristic of dropping hammer further, Ti content is preferably more than 0.050 quality %, is more preferably more than 0.055 quality %.In addition, from the viewpoint of improving the toughness of deposited metal and characteristic of dropping hammer further, Ti content is preferably below 0.070 quality %, is more preferably below 0.065 quality %.

< surplus: Fe and inevitably impurity >

The surplus of the composition of flux-cored wire is Fe and inevitable impurity.As inevitable impurity, such as, V, W, Nb, Co, Sn, Sb, As etc. can be enumerated.These inevitable impurity are allowed and to be contained in the scope not hindering effect of the present invention, and its content is preferably below 0.005 quality % respectively.

Flux-cored wire of the present invention described above is mainly suitable for the gas metal arc welding of Mn-Mo-Ni steel that pressure vessel or reservoir vessel etc. in energy plant or chemical plant, energy source raw material bunkerage use, Ni steel.

Next, the manufacture method of flux-cored wire of the present invention is described.

Flux-cored wire of the present invention can be manufactured by common method.Such as, first, use converter or electric furnace etc., will there is the molten steel of mentioned component composition, manufacture steel (steel billet etc.) by the molten steel of gained by continuous casting or ingot casting method etc.Next, by after the heat steel that manufactures, implement hot rolling (extrusion calendaring), implement further cold rolling (cold-drawn wire) of dry type, Production Example is if the welding welding wire of φ 5.5mm is with former line (also referred to as steel wire).Next, the former line of this welding welding wire is implemented annealing, pickling as required, carries out Wire Drawing, manufacture the flux-cored wire with final gage of wire (such as 1.2mm).

Embodiment

Below, about the embodiment falling into scope of the present invention, its effect is compared with the comparative example departing from scope of the present invention and is described.

First, use electric furnace to carry out ingot casting to molten steel, and carry out extrusion calendaring, cold-drawn wire, the welding welding wire producing φ 5.5mm, with after former line, carries out wire drawing to this welding welding wire with former line and reaches φ 2.4mm.Next, carry out intermediate annealing and copper plating treatment and make middle wire drawing, the final wire drawing of further enforcement, implements skin-pass and is coated with lubricating oil, finally producing the GMAW flux-cored wire with chemical composition shown in table 1 (quality %) of gage of wire φ 1.2mm.

Next, use the GMAW flux-cored wire of chemical composition, the breadboard of the bevel shape shown in Fig. 1 shown in table 1, weld under welding condition shown in table 2 and table 3, evaluate deposited metal overall tensile strength, toughness and characteristic of dropping hammer.The overall engineering properties of deposited metal is that both is evaluated to " under the state after welding " and " after PWHT (615 DEG C × 10h) ".It should be noted that, in Table 1, the situation not meeting scope of the present invention can represent by logarithm value interpolation underscore.

Table 1

Table 2

Table 3

Gage of wire for test weld silk exists multiple, but the embodiment of the application with the diameter of 1.2mm for representative.For welding posture and stacked main points, consider the welding procedure that utilizes real machine and from the view point of execution conditions, wish to evaluate with the engineering properties of the strictest condition to deposited metal, be set to upward welding in the vertical position posture and the construction of each layer 1 road, its stacked number is set to 4 layers.If can apply upward welding in the vertical position posture, then other posture also can be carried out.Common GMAW uses the O comprising about 1 ~ 5% ₂ar gas or comprise about 10 ~ 20% CO ₂ar gas, but in the application protective gas composition with Ar-10%CO ₂for representative, its flow is set to 25L/min.In addition, incidentally whether with pulse welding function has nothing to do bonding machine, but uses the bonding machine being accompanied with pulse welding function in the embodiment of the application.

In addition, in the evaluation of the tensile strength characteristic that deposited metal is overall, provide from the thickness of slab central portion of deposited metal on sealing wire direction according to the tensile test at room temperature sheet (test film diameter: φ 12.5mm, parallel portion length: 50.0mm) that AWS B4.0 gathers.In addition, in the evaluation of toughness, provide from the thickness of slab central portion of deposited metal sealing wire and normal direction (seam direction) according to the Charpy-type test sheet of the 2mm-V breach (side breach (side notch)) of AWS B4.0.In addition, drop hammer in the evaluation of characteristic at deposited metal, the drop weight test sheet according to ASTM E208-2006 is provided.It should be noted that, the test film shape of drop weight test sheet is set to P-3 type test film.Each test film collection position is shown in Fig. 2 and Fig. 3.

In this embodiment, for the tensile strength characteristic that deposited metal is overall, be that the test film of more than 587MPa is evaluated as zero by TS, the test film being less than 587MPa is evaluated as ×.In addition, for toughness, the test film being more than 100J by 3 mean values of the impact value (following, to be designated as vE-39 DEG C) when-39 DEG C is evaluated as ◎, by more than 55J and the test film being less than 100J is evaluated as zero, the test film being less than 55J is evaluated as ×.In addition, for characteristic of dropping hammer, by RT _nDTfor the test film of less than-75 DEG C is evaluated as ◎, will-75 DEG C be exceeded and the test film of less than-50 DEG C is evaluated as zero, the test film exceeding-50 DEG C is evaluated as ×.At this, RT _nDTderive according to " generating nuclear facilities specifications design builds specification the 4th chapter annex 4-1 ".Show the result in table 4.

Table 4

As shown in table 4, No.1 ~ 7 meeting scope of the present invention are good in whole assessment items.

On the other hand, No.8 ~ 22 not meeting scope of the present invention are following result.

The C content of No.8 is low, and therefore the tensile strength characteristic of " PWHT (615 DEG C × 10h) afterwards " is poor.The C content of No.9 is high, therefore the characteristic difference of dropping hammer of the toughness of " under the state after welding ", characteristic of dropping hammer and " PWHT (615 DEG C × 10h) afterwards ".

The Si content of No.10 is low, and the tensile strength characteristic of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards " is poor.The Si content of No.11 is high, therefore toughness, characteristic of the dropping hammer difference of " under the state after welding ".

The Mn content of No.12 is low, therefore toughness, characteristic of the dropping hammer difference of " under the state after welding ".The Mn content of No.13 is high, therefore toughness, characteristic of the dropping hammer difference of " under the state after welding ".

The P content of No.14 is high, therefore the characteristic difference of dropping hammer of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards ".The S content of No.15 is high, therefore the characteristic difference of dropping hammer of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards ".The Cu content of No.16 is high, therefore the characteristic difference of dropping hammer of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards ".

The Ni content of No.17 is low, therefore toughness, characteristic of the dropping hammer difference of " under the state after welding ".The Ni content of No.18 is high, therefore the characteristic difference of dropping hammer of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards ".

The Mo content of No.19 is low, and therefore the tensile strength characteristic of " PWHT (615 DEG C × 10h) afterwards " is poor.The Mo content of No.20 is high, therefore the characteristic difference of dropping hammer of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards ".

The Ti content of No.21 is low, and therefore the tensile strength characteristic of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards " is poor.The Ti content of No.22 is high, therefore toughness, characteristic of the dropping hammer difference of the toughness of " under the state after welding ", characteristic of dropping hammer, " PWHT (615 DEG C × 10h) afterwards ".

Next, shown in the embodiment 7 of use table 1, the GMAW welding wire of chemical composition, according to the welding condition shown in table 5, carries out soldering test, evaluates the engineering properties of deposited metal under various welding posture and weld heat input.Between preheating, road, temperature is set to 200 ~ 220 DEG C, and protective gas is set to Ar-10%CO ₂(25L/min), tip, mother metal spacing are set to 15 ~ 20mm.In addition, the bonding machine of this embodiment also uses the bonding machine being accompanied with pulse welding function, and its impulsive condition is according to table 3.

Table 5

In the embodiment of this, assessment item is identical with aforesaid embodiment with test film acquisition method etc.For the tensile strength characteristic that deposited metal is overall, be that the test film of more than 587MPa is evaluated as zero by TS, the test film being less than 587MPa is evaluated as ×.In addition, for toughness, the test film of 3 more than average out to 100J of the impact value (following, to be designated as vE-39 DEG C) when-39 DEG C is evaluated as ◎, by more than 55J and the test film being less than 100J is evaluated as zero, the test film being less than 55J is evaluated as ×.In addition, for characteristic of dropping hammer, by RT _nDTfor the test film of less than-75 DEG C is evaluated as ◎, will-75 DEG C be exceeded and the test film of less than-50 DEG C is evaluated as zero, the test film exceeding-50 DEG C is evaluated as ×.Show the result in table 6.

Table 6

As shown in table 6, No.23 ~ 26 meeting scope of the present invention are good in whole assessment items.

Above, to illustrating that about the present invention embodiment and embodiment have been described in detail, purport of the present invention is not limited to above-mentioned content, and its interest field must the extensive interpretation based on the record of technical scheme.It should be noted that, content of the present invention can carry out extensive modifications, change etc. based on described record certainly.

Claims

1. a gas metal arc welding flux-cored wire; it is characterized in that; containing C:0.010 ~ 0.100 quality %, Si:0.20 ~ 1.00 quality %, Mn:1.00 ~ 2.00 quality %, below P:0.025 quality %, S:0.025 below quality %, below Cu:0.35 quality %, Ni:4.00 ~ 5.00 quality %, Mo:0.10 ~ 0.50 quality %, Ti:0.025 ~ 0.075 quality %, surplus is made up of Fe and inevitable impurity.

2. a gas metal arc welding flux-cored wire; it is characterized in that; containing C:0.010 ~ 0.050 quality %, Si:0.20 ~ 0.50 quality %, Mn:1.10 ~ 1.40 quality %, below P:0.010 quality %, S:0.010 below quality %, below Cu:0.35 quality %, Ni:4.00 ~ 4.50 quality %, Mo:0.10 ~ 0.30 quality %, Ti:0.050 ~ 0.075 quality %, surplus is made up of Fe and inevitable impurity.