JP3767796B2 - Stainless steel flux cored wire - Google Patents

Description

【００３８】
【表２】

【００３９】
【表３】

【００４０】
【表４】

【００４１】
【表５】

【００４２】
【表６】

【００４３】
試験鋼板は、表１に示す成分のＳＵＳ３０４鋼板を用いてＴ字型に組み立て、片側１パス水平すみ肉溶接を行い確認した。作業性評価は実用上良好な場合は○、実用上問題がある場合は×とした。溶接作業性のスパッタ発生量は、表１に示す同成分のＳＵＳ３０４鋼板（６ｍｍｔ×２０ｍｍｗ×５００ｍｍｌ）を図３に示すように試験板４として固定鋼板５上に載置し、固定器具９により固定する。次いで、上部が溝状に開口した銅製のスパッタを捕集する捕集箱８で、溶接作業部を覆い、上部開口部から溶接トーチ６を挿入し、溶接トーチ６からフラックス入りワイヤ７を送給して試験板４を溶接した。溶接作業により銅製の捕集箱８内にて発生したスパッタを捕集し、質量を測定した。溶接条件は下向姿勢にて溶接作業性を評価した条件で行い、溶接時間は１分間で単位時間当たりの発生量（ｇ／ｍｉｎ）にて評価した。ワイヤ径０．８ｍｍの場合、０．２６ｇ／ｍｉｎ以下は◎（極めて良好）、０．３２ｇ／ｍｉｎ以下は○（良好）、０．３２ｇ／ｍｉｎより多い場合は×とした。ワイヤ径１．２ｍｍの場合、０．３５ｇ／ｍｉｎ以下は◎（極めて良好）、０．４２ｇ／ｍｉｎ以下は○（良好）、０．４２ｇ／ｍｉｎより多い場合は×とした。１．６ｍｍの場合、０．８８ｇ／ｍｉｎ以下は◎（極めて良好）、１．４ｇ／ｍｉｎ以下は○（良好）、１．４ｇ／ｍｉｎより多い場合は×とした。溶接作業性がすべて良好なものは、溶着金属性能を評価した。評価は全容着金属からＪＩＳ Ｚ ３３２３／Ａ１号試験片を採取し、引張試験を行った。
【００４４】
総合判定は、全ての評価項目で良好なものは○、それ以外は×とした。それらの結果を表７に示す。
【００４５】
【表７】

【００４６】
本発明例であるワイヤＮｏ．１〜１３は、スラグ剤成分およびスラグ剤成分の合計量、さらに金属粉成分および金属粉の合計量が適正量からなるフラックスをステンレス鋼外皮に適量充填されているので、溶接作業性、溶着金属の引張試験においても良好な結果であった。スパッタ発生量に関しては、溶接電流が低いワイヤＮｏ．１２はスパッタ発生量が０．３５ｇ／ｍｉｎであり、溶接電流が高いワイヤＮｏ．１３はスパッタ発生量が０．３８ｇ／ｍｉｎで、溶接電流の大小でスパッタ発生量に大きく影響することはなかった。
【００４７】
比較例中ワイヤＮｏ．１４は、Ａｌ₂Ｏ₃量が多いのでスラグの凝固が早く、スラグがビードを均一に被包せず、ビード形状が不良となった。
【００４８】
ワイヤＮｏ．１５は、Ａｌ₂Ｏ₃量が少ないのでスラグが垂れ、被包性および剥離性が劣化した。また、ビード形状も不良であった。さらに、溶滴が円滑に移行せず、スパッタ発生量が増加した。
【００４９】
ワイヤＮｏ．１６は、ＺｒＯ₂量が多いのでスラグの流動性が悪く、ビード形状が不良となった。また、スラグの焼付きを生じ、スラグ剥離性が悪くなった。さらに、スパッタ発生量が増加した。
【００５０】
ワイヤＮｏ．１７は、ＺｒＯ₂量が少ないのでスラグが流れやすく、スラグがビードを均一に被包せず被包性が劣化し、ビード形状が不良となった。さらに、アーク状態が不安定でスパッタ発生量も増加した。
【００５１】
ワイヤＮｏ．１８は、金属弗化物が多いのでスラグが垂れ被包性およびビード外観が劣化した。さらに、アーク状態が不安定でスパッタ発生量も増加した。
【００５２】
ワイヤＮｏ．１９は、金属弗化物が少ないのでアーク状態が不安定で溶滴の移行が円滑に行われず、スパッタ発生量は増加した。さらに、スラグ剥離性の効果が得られずスラグ剥離性が劣化した。
【００５３】
ワイヤＮｏ．２０は、カリウム化合物が多すぎて、アーク状態が不安定でスパッタ発生量が増加した。
【００５４】
ワイヤＮｏ．２１は、カリウム化合物が少ないのでアーク状態が不安定で溶滴の移行が円滑に行われず、スパッタ発生量が増加した。
【００５５】
ワイヤＮｏ．２２は、弗素換算値［Ｆ］、カリ換算値［Ｋ］とした場合、Ｘ＝（［Ｆ］＋「Ｋ」）／［Ａｌ₂Ｏ₃＋ＺｒＯ₂］の式で求められるＸが大きいのでスラグの被包性が劣化し、さらに、ビード形状が不良であった。
【００５６】
ワイヤＮｏ．２３は、弗素換算値［Ｆ］、カリ換算値［Ｋ］とした場合、Ｘ＝（［Ｆ］＋「Ｋ」）／［Ａｌ₂Ｏ₃＋ＺｒＯ₂］の式で求められるＸが小さいのでアーク状態が不安定でスパッタ発生量が増加した。さらに、スラグが垂れ、スラグ被包性が劣化した。
【００５７】
ワイヤＮｏ．２４は、金属炭酸塩が含まれているためワイヤ先端から溶滴が離脱する際に爆発を起こし、シールドガスにＡｒ−ＣＯ₂を使用しているにもかかわらず、スパッタ発生量が増加した。
【００５８】
ワイヤＮｏ．２５は、フラックス中と外皮中の窒素の合計が多いのでスラグがビードにこびり付き、スラグ剥離性を劣化させた。
【００５９】
ワイヤＮｏ．２６は、ＴｉＯ₂量が多いのでスパッタ発生量が増加した。さらに、スラグの流動性が低下しビード形状が不良となるばかりか、ビード表面にテンパーカラーが付き外観も劣化させた。
【００６０】
ワイヤＮｏ．２７は、ＴｉＯ₂量が少ないのでアークが不安定となり、スパッタ発生量が増加した。さらに、スラグの被包性および剥離性が悪くなり、ビード形状も不良となった。
【００６１】
ワイヤＮｏ．２８は、ＳｉＯ₂量が多いのでスラグが流れやすくビードに均一に被包せず被包性が劣化し、ビード形状が不良となった。さらに、スラグの焼付を生じ、スラグ剥離性が劣化した。
【００６２】
ワイヤＮｏ．２９は、ＳｉＯ₂量が少ないのでスラグの流動性が悪く、被包性および剥離性が不十分で、ビード形状が不良となった。
【００６３】
ワイヤＮｏ．３０は、ナトリウム化合物が多いのでスラグがビードにこびり付き剥離性が劣化した。
【００６４】
ワイヤＮｏ．３１は、ナトリウム化合物が少ないのでアーク状態が不安定でスパッタ発生量が増加した。
【００６５】
ワイヤＮｏ．３２は、スラグ剤成分の合計が多いのでスパッタ発生量が増加した。さらに、フラックス充填率が高いのでアーク状態が不安定でスパッタ発生量が増加した。さらに、フラックス充填率が高いのでワイヤ外皮が薄く、伸線加工中に断線が多発し、フラックス入りワイヤの生産能率を著しく低下させた。
【００６６】
ワイヤＮｏ．３３は、ビスマス量が多いのでスラグが垂れビード表面にテンパーカラーが付きビード外観を劣化させた。さらに、溶接ビードのクレータ部に凝固割れを発生した。
【００６７】
ワイヤＮｏ．３４は、ビスマス量が少ないのでスラグ剥離性の効果が得られずスラグ剥離性が劣化した。
【００６８】
【発明の効果】
以上、詳述したように本発明のステンレス鋼溶接用フラックス入りワイヤは、ステンレス鋼の溶接において、高電流条件においても、アークが安定し、スパッタ発生量が少なく、さらにビード形状、スラグの焼付がなく、スラグの被包性および剥離性が優れ、かつ溶着金属性能が良好なステンレス鋼溶接用フラックス入りワイヤとして有益である。
【図面の簡単な説明】
【図１】 Ｘ値とスパッタ発生量の関係を示す図である。
【図２】 フラックス入りワイヤの断面図である。
【図３】 スパッタ発生量測定方法の説明図で、（ａ）は断面斜視図、（ｂ）は側面図である。
【符号の説明】
【００６９】
１ 外皮
２ 充填フラックス
３ 継ぎ目
４ 試験板
５ 固定鋼板
６ 溶接トーチ
７ フラックス入りワイヤ
８ 捕集箱
９ 固定器具[0001]
BACKGROUND OF THE INVENTION
  The present invention is used for welding stainless steel, and has a high workability even under high current conditions, in particular, a small amount of spatter generation, good slag encapsulation and peelability, and good weld metal performance. The present invention relates to a flux-cored wire for steel welding.
[0002]
[Prior art]
  Stainless steel welding methods include covered arc welding rods, gas shielded arc welding, submerged arc welding, TIG welding, plasma welding, and the like, each of which is used corresponding to the welding application. Among them, gas shield arc welding using a flux-cored wire has a wide condition range and can be welded in each posture. In addition, it has a feature that it can be welded with high efficiency and has a good welding finish, and many flux-cored wires are used. This CO₂In gas shielded arc welding, it is required to further improve the working efficiency. As a method for improving the welding efficiency, a method using a wire having a large wire diameter, a metal-based flux-cored wire, or increasing the welding current is used.
[0003]
  However, when a wire with a large wire diameter is used, it can be applied only to thick plates because the arc force is strong and the steel sheet melts.Ar-CO ₂ ofSince a mixed gas must be used, the welding cost increases.
[0004]
  When a metal-based flux-cored wire is used, it is difficult to ensure sufficient slag encapsulation and peelability compared to the case where a normal flux-cored wire is used, and the bead shape is somewhat worse.
[0005]
  Further, when the welding current is increased, the welding workability is deteriorated. In particular, the amount of spatter generated increases, the slag encapsulation property deteriorates, and further, the slag seizure occurs and the slag peelability deteriorates.
[0006]
  Thus, Japanese Patent No. 1720735 is disclosed as a flux-cored wire for welding stainless steel. The main component SiO₂, ZrO₂TiO₂There is a flux-cored wire that limits the slag agent component and metal component in the system flux, has a small amount of spatter generation, and has excellent arc state, droplet transferability and welding efficiency. JP-A-2-251395 discloses SiO as a main component.₂, ZrO₂TiO₂There is a flux-cored wire that limits the total content of slag and the slag component, is excellent in slag encapsulation, has low spatter generation, and has good arc stability. Furthermore, the flux-cored wire, flux component and outer skin component of Japanese Patent Application Laid-Open No. 7-276084, which has excellent porosity resistance and reduced spatter generation amount and improved slag peelability, are limited to reduce spatter generation amount. There is a flux-cored wire disclosed in JP-A-11-129093.
[0007]
  However, when welding is performed using a conventional flux-cored wire as described in Japanese Patent No. 1720735, Japanese Patent Application Laid-Open No. 2-251395, and Japanese Patent Application Laid-Open No. 7-276084, for example, a wire diameter of 1.2 mm In the case where the welding current is about 200 amperes, good welding workability and weld metal performance are exhibited. However, in the welding where the welding current exceeds 250 amperes, the amount of spatter is increased and the slag is beaded. It was not sufficiently encapsulated, and slag seizure occurred, which was insufficient in practice. If the amount of spatter generated is large, it will adhere to the product and require removal. Further, when seizure of the slag occurs, not only the slag remains in the bead and the appearance is deteriorated, but also the corrosion resistance of the remaining portion of the slag is deteriorated. Therefore, the slag removal work is required, and the work efficiency is greatly reduced.
[0008]
  Next, the flux-cored wire described in JP-A-11-129093 is ZrO.₂The slag peelability is ensured without inclusion. However, ZrO₂If, for example, the wire diameter is 1.2 mm, the slag is not uniformly encapsulated and the bead droops and the shape becomes insufficient at a high current where the welding current exceeds 250 amperes. This becomes more noticeable as the welding current increases.
[0009]
  Therefore, when the wire diameter is 1.2 mm, the welding current is 250.AmpereThere is a strong demand for a flux-cored wire for welding stainless steel with good welding workability and weld metal performance even under welding conditions that exceed.
[0010]
[Problems to be solved by the invention]
  In order to solve the above-mentioned problems, the present invention has been variously studied about the slag agent component of the flux-cored wire filled in the stainless steel sheath, and the normal welding current is naturally high in the welding of stainless steel. Stainless steel with stable arc, low spatter generation, good bead shape, no slag seizure, excellent slag encapsulation and peelability, and good weld metal performance It aims at providing the flux cored wire for welding.
[0011]
[Means for Solving the Problems]
  The inventors of the present invention are used for welding stainless steel and have excellent welding workability even when the welding current is high.₂O_ThreeAnd ZrO₂The amount of spatter generated in high current welding is reduced by limiting the ratio of the metal fluoride and potassium compound to the total value of slag, and the total amount of slag agent components with good weld metal performance The problem is achieved by limiting the flux filling rate and the like.
[0012]
  The gist of the present invention is as follows.
[0013]
  (1) In the stainless steel welding wire formed by filling the outer shell made of austenitic stainless steel with a flux, the wire diameter is 0.8 to 1.6 mm, and the filling flux is mass% with respect to the total mass of the wire.
Al₂O_Three: 0.1 to 1.6%
ZrO₂: 0.2 to 3.5%
Metal fluoride (fluorine conversion value): 0.04 to 0.15%,
Potassium compound (potassium conversion value): 0.04 to 0.2% included,
In addition, when the fluorine conversion value [F] and the potassium conversion value [K] are used,
X = ([F] + [K]) / [Al₂0_Three+ ZrO₂And the value of X is
0.025 ≦ X ≦0.094Satisfied,
Metal carbonate: Fill the stainless steel shell with a flux of 0.01% or less 17-26%,
Total nitrogen in flux and outer skin: 0.04% or less
A flux-cored wire for welding stainless steel, characterized by
[0014]
  (2) By mass%
TiO₂: 0.8 to 4.0%,
SiO₂: 1.1-3.8%
Sodium compound (sodium equivalent value): including 0.01 to 0.3%,
Total slag component: 4.5 to 11.0%
The flux-cored wire for welding stainless steel as described in (1) above, wherein
[0015]
  (3) The flux-cored wire for welding stainless steel as described in (1) or (2) above, containing one or two of metal bismuth or bismuth oxide in a total amount of 0.005 to 0.1%.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  First, the reasons for limiting each component of the filled flux of the inventive stainless steel welding flux cored wire will be described.
[0017]
  Al₂O_Three: 0.1 to 1.6%
  Al₂O_ThreeAdjusts the fluidity of the slag to improve the encapsulation of the slag and the bead shape. Al₂O_ThreeIs a high-melting-point oxide with a melting point of 2050 ° C., forming a protrusion from the wire of the filling flux to the base material, and the molten metal moves along the protrusion and moves away from the tip to form a fine droplet. Stable transfer to suppress spattering. However, Al₂O_ThreeIf it is less than 0.1%, the slag will sag, the encapsulation will deteriorate, seizure of the slag will occur, and the bead shape will also deteriorate. Further, the protrusion of the filling flux becomes insufficient, the molten metal moves irregularly, the droplets vary in size, and cannot smoothly move, and the amount of spatter generated increases. On the other hand, if it exceeds 1.6%, the melting point of the slag becomes high and the solidification is quick, so that the slag does not encapsulate the bead surface uniformly and the bead shape is also deteriorated. Therefore, Al₂O_ThreeIs 0.1 to 1.6%. Al₂O_ThreeAs a raw material, alumina, potassium feldspar, etc. can be used.
[0018]
  ZrO₂:0.2~ 3.5%
  ZrO₂Is a slag fluidity regulator, forms slag with good bead surface encapsulation and peelability, and has a good bead shape. In addition, Al₂O_ThreeIn the same way as above, it is a high melting point oxide with a melting point of 2700 ° C., which forms protrusions from the wire of the filling flux to the base material, and the molten metal moves along the protrusions and moves away from the tip, and then comes off from the tip and dissolves in fine particles. It is a component that is stably transferred as a droplet and suppresses the generation of spatter. However,0.2If it is less than%, the slag tends to flow, and the slag does not uniformly enclose the bead, resulting in a poor bead shape. Further, the protrusion of the filling flux becomes insufficient, the molten metal moves irregularly, the droplets vary in size, and cannot smoothly move, and the amount of spatter generated increases. On the other hand, if it exceeds 3.5%, the fluidity of the slag is poor and the bead shape is poor. Furthermore, the slag is seized on the bead surface, and the slag peelability is lowered. ZrO₂As a raw material, zircon sand, zircon flower, zircon oxide, etc. can be used.
[0019]
  Metal fluoride (fluorine conversion value): 0.04 to 0.15%
  Metal fluoride stabilizes the arc and has the effect of lowering the melting point and viscosity of the molten slag, making it easier for the molten metal to detach from the wire tip. Furthermore, it is an effective component for the slag peelability. However, if the metal fluoride is less than 0.04%, the arc state becomes unstable, the molten metal is not smoothly detached, and the amount of spatter generated increases. Furthermore, a sufficient effect for slag peeling cannot be obtained, and the slag peelability deteriorates. on the other hand,0.15If it exceeds 50%, the viscosity of the molten slag becomes low and the molten slag drips, the slag cannot uniformly cover the bead surface, and a temper color is attached to the bead surface, so that the bead appearance is deteriorated. Furthermore, the arc state becomes unstable due to too much, and the amount of spatter generated increases. Metal fluoride raw materials include sodium fluoride, potassium silicofluoride, aluminum fluoride, calcium fluoride, lithium fluoride, magnesium fluoride, barium fluoride, strontium fluoride, zirconium fluoride, cerium fluoride, cryolite These raw materials are used alone or in combination, and the amount is 0.04 to 0.04 in terms of fluorine.0.15Use in the range of%.
[0020]
  Potassium compound (calcium equivalent value): 0.04 to 0.2%
  The potassium compound stabilizes the arc and lowers the melting point and viscosity of the molten slag as in the case of the metal fluoride, and makes it easy for the molten metal to be detached from the wire tip. However, if the potassium compound is less than 0.04%, the arc state becomes unstable, the molten metal is not detached smoothly, and the amount of spatter generated increases. On the other hand, even if it exceeds 0.2%, the arc state is unstable and the amount of spatter generated increases. Therefore, the potassium compound (potassium conversion value) is 0.04 to 0.2%. Potassium raw materials include potassium titanate, potassium silicofluoride, zircon potassium fluoride, potassium oxide and the like. These raw materials are used alone or in combination, and the amount is 0.04 to 0.2% in terms of potash. It is a range.
[0021]
  When fluorine conversion value [F] and potash conversion value [K] are used, X = ([F] + [K]) / [Al₂O_Three+ ZrO₂And the X is 0.025 ≦ X ≦0.094
  The fluorine compound and potassium compound have the effect that the fluorine and potassium stabilize the arc and lower the melting point and viscosity of the molten slag, so that the molten metal is easily detached from the wire tip. Al₂O_ThreeAnd ZrO₂Is a high melting point oxide, and has an effect of forming a protrusion from the wire to the base material and allowing the molten metal detached from the tip of the wire to travel along the protrusion and stably move. However, the range is that of fluorine compounds fluorine and potassium compounds potassium and Al₂O_ThreeAnd ZrO₂It is kept in balance with the content of. In order to suppress the amount of spatter generated, it is necessary to perform smooth detachment of the molten metal and stable transfer of the separated molten metal. [F] + [K] and [Al] to maintain a stable arc state and make the droplets finer and transfer₂O_Three+ ZrO₂] Have been found to have the best blending ratio.
[0022]
  FIG. 1 shows the relationship between the X value and the amount of spatter generated. In order to clarify the influence of the X value and the amount of spatter generated, the wire of the present inventionNo. 12Fluoride, potassium compound, A1 related to X value₂O_Three, ZrO₂Only the changes were investigated. As a result, ([F] + [K]) / [Al₂O_Three+ ZrO₂] Where X is 0.025 ≦ X ≦0.094Must. That is, as shown in FIG. 1, when X is less than 0.025, the arc becomes unstable and the amount of spatter generation increases, and the allowable spatter generation amount of 0.42 g / min or less is not satisfied. Furthermore, the melting point of the slag increases and the viscosity also decreases. Therefore, the slag encapsulation state and bead shape deteriorate. Also,0.094Even if it is super high, the arc state becomes unstable and the amount of spatter generated increases, and the allowable spatter generation amount of 0.42 g / min or less was not satisfied. Furthermore, the melting point and viscosity of the slag are lowered, the slag is dripped, and the slag encapsulation is deteriorated.
[0023]
   TiO₂: 0.8-4.0%
   TiO₂Stabilizes the arc and forms a slag with good bead encapsulation and peelability. further,MeltingThis has the effect of preventing the molten metal from dripping from the proper viscosity of the slag and improving the bead shape. If it is less than 0.8%, the arc becomes unstable and the amount of spatter generated increases. Furthermore, the slag encapsulation and peelability are reduced, and the bead shape is deteriorated. On the other hand, if it exceeds 4.0%, not only the amount of spatter is increased but also slag entrainment is likely to occur. Furthermore, not only the fluidity of the slag is lowered and the bead shape becomes poor, but also the temper color is attached to the bead surface and the appearance is remarkably deteriorated. TiO₂As the raw material, rutile, titanium slag, illuminite, potassium titanate, sodium titanate and the like can be used.
[0024]
  SiO₂: 1.1-3.8%
  SiO₂Is a component that is necessary for adjusting the fluidity of the molten slag, forms a slag with good bead encapsulation and peelability, and improves the bead shape. However, if it is less than 1.1%, the slag fluidity is poor. Encapsulation is inadequate and slag peelability also deteriorates. Furthermore, the bead shape becomes defective. On the other hand, if it exceeds 3.8%, the slag tends to flow, the slag does not uniformly encapsulate the bead surface, and the bead shape becomes poor due to insufficient encapsulation. Furthermore, seizure of the slag occurs, and the slag peelability decreases. SiO₂As raw materials, cinnabar, aragonite, potash feldspar and the like can be used.
[0025]
  Metal carbonate: 0.01% or less (including 0%), even if included, unavoidable impurities
  Metal carbonate generates CO gas by thermal decomposition during welding. Therefore, an explosion phenomenon occurs when the droplets are detached from the tip of the wire, resulting in spatter and an increase in the amount of spatter generated. Accordingly, the metal carbonate is preferably 0%, but when it is contained as an unavoidable impurity, it is acceptable up to 0.01%.
[0026]
  Total nitrogen in flux and outer skin: 0.04% or less
  If nitrogen is contained in the flux or the outer skin, the slag sticks to the bead, the slag peelability is deteriorated, the number of processes for slag removal is increased, and the work efficiency is lowered. When the nitrogen content is abnormally large, slag splashing occurs immediately after welding and is not preferable. Therefore, it is desirable that nitrogen is low, and even if it is included as an unavoidable impurity, it is 0.04% or less.
[0027]
  Wire diameter: 0.8-1.6mm
  For welding of thin stainless steel plates having a plate thickness of 1 mm or 1.5 mm, an appropriate welding condition can be selected by using a flux-cored wire with a thin wire diameter, and welding can be performed without melting the plate. Therefore, a thinner flux-cored wire is advantageous for thin plate welding. However, if the wire diameter is thinner than 0.8 mm, the arc becomes unstable in the case of high current welding. On the other hand, if the diameter of the flux-cored wire is thicker than 1.6 mm, in the gas shield arc welding, the arc spray is too strong, the spatter becomes large and the generation amount increases, and the bead shape also deteriorates. Therefore, the wire diameter was set to 0.8 to 1.6 mm.
[0028]
  Filling rate: 17-26%
  When the flux filling rate into the stainless steel outer shell is less than 17%, the outer shell is thick, the droplets are enlarged, and the amount of spatter is increased. On the other hand, if it exceeds 26%, the thickness of the outer skin is thin, the protrusion of the unmelted filling flux becomes abnormally long, the arc becomes unstable, the amount of spatter is increased, and a better bead shape is obtained. It can no longer be obtained. In addition, since the outer skin is thin, breakage is likely to occur frequently during wire drawing, which reduces the production efficiency.
[0029]
  Sodium compound (sodium equivalent value): 0.01 to 0.3%
  The sodium compound stabilizes the arc state by making the droplet transfer small and smooth. When it is less than 0.01% in terms of sodium, the droplets become large, the transition is not performed smoothly, the arc state becomes unstable, and the amount of spatter generated increases. If it exceeds 0.3%, the slag fluidity becomes uneven and solidification segregation occurs, and the solidified slag is not peeled off as a single piece. In particular, sticking tends to occur at the end of the bead. Therefore, the sodium compound is 0.01 to 0.3% in terms of sodium. As the sodium compound raw material, sodium fluoride, sodium oxide, sodium titanate and the like can be used. If the sodium conversion value is in the range of 0.01 to 0.3%, they can be used alone or in combination.
[0030]
  Total slag component: 4.5 to 11.0%
  The slag component in the filling flux forms the proper viscosity and protrusion length to reduce the droplet size, stabilize the droplet transfer, reduce the amount of spatter, encapsulate and peelability A good slag is formed and the bead shape is improved. Therefore, if the total of the slag agent components is less than 4.5%, the slag cannot sufficiently encapsulate the beads, and the bead shape becomes poor. Furthermore, slag seizure occurs and slag peelability is reduced. In particular, the higher the current, the greater these trends. On the other hand, if it exceeds 11.0%, the amount of spatter generated increases, and the slag becomes excessive, resulting in defects in slag entrainment. In addition, the slag agent component in this invention is nonmetallic components, such as an oxide and a fluoride.
[0031]
  Total of metal bismuth or bismuth oxide: 0.005 to 0.1%
  Bismuth is a very effective ingredient for slag peeling,0.005If it is less than%, the effect is not seen, and the slag peelability deteriorates. If it exceeds 0.1%, slag will sag, and a temper color will be attached to the bead surface, deteriorating the bead appearance. Furthermore, since it is a low melting point metal, it segregates at the grain boundary at the time of final solidification, and external forces such as deformation stress are applied to cause solidification cracks. Therefore, bismuth is the sum of metal bismuth or bismuth oxide.0.005-0.1%. Bismuth metal and bismuth oxide can be used alone or in combination, with no significant difference between when used alone and when used together.
[0032]
  The shielding gas used in the gas shielded arc welding of the flux cored wire of the present invention is 100% CO2.₂Has the effect of reducing spatter generation at 20% CO2.₂In a mixed gas such as -Ar, the arc was more stable and the amount of spatter was reduced. Further, the filling flux adjusts the alloy component in accordance with the chemical component of the stainless steel arc welding flux-cored wire weld metal in JIS Z 3323. As the adjuster, the alloy material components include Ni, Cr, Mn, Mo, Nb, Si, Fe, Ti, Al, Cu, Bi, and further, these alloy materials, stainless powder, metal nitride, and the like.
[0033]
  Furthermore, depending on the raw material particle size, flux component, filling method, etc., it may be granulated with a fixing agent, but in that case, the component derived from the fixing agent, for example, in the case of water glass, SiO₂, Na₂O, K₂It is necessary to mix the raw materials so that the increase in O and the like is taken into consideration in advance.
[0034]
  An example of the flux-cored wire of the present invention is shown in FIGS. 2 (a) to 2 (d), and the cross-sectional shape of the flux-cored wire is that a shell 1 made of stainless steel pipe or strip is encapsulated with a filling flux 2. 2 with no joints as shown in FIG. 2 (a) or in FIGS. 2 (b)-(d)
As shown in FIG.
【Example】
[0035]
  Stainless steel with wire diameters of 0.8 mm, 1.2 mm, and 1.6 mm using stainless steel pipes and strips with the components shown in Table 1 and changing the filling rate of the flux shown in Tables 3 to 6 with respect to the total mass of the wire. A flux-cored wire for steel welding was produced. The pipe was drawn to a diameter at which the flux entered at a predetermined filling rate, and then filled with the flux. In Tables 3 to 6, the wire No. 1 to13Is a flux-cored wire of the present invention example,No. 14-34Is a comparative example.
[0036]
  The welding workability was evaluated by automatic welding under the conditions shown in Table 2.
[0037]
[Table 1]

[0038]
[Table 2]

[0039]
[Table 3]

[0040]
[Table 4]

[0041]
[Table 5]

[0042]
[Table 6]

[0043]
  The test steel plates were assembled in a T shape using SUS304 steel plates having the components shown in Table 1, and confirmed by performing one-pass horizontal fillet welding on one side. In the evaluation of workability, “◯” was given when practically good, and “X” was given when practically problematic. The amount of spatter generated during welding workability was set on a fixed steel plate 5 as a test plate 4 as shown in FIG. 3 and a SUS304 steel plate (6 mmt × 20 mmw × 500 mml) of the same component shown in Table 1 was fixed by a fixture 9. To do. Next, the welding box is covered with a collection box 8 for collecting copper spatter having an upper opening in a groove shape, a welding torch 6 is inserted from the upper opening, and a flux-cored wire 7 is fed from the welding torch 6. Then, the test plate 4 was welded. Spatter generated in the copper collection box 8 by the welding operation was collected, and the mass was measured. Welding conditions were performed under the condition that the welding workability was evaluated in a downward posture, and the welding time was evaluated in terms of the amount of generation (g / min) per unit time per minute. When the wire diameter is 0.8 mm, ｍｍ (very good) is 0.26 g / min or less, ◯ (good) is 0.32 g / min or less, and x is more than 0.32 g / min. In the case of a wire diameter of 1.2 mm, 0.35 g / min or less was marked as ◎ (very good), 0.42 g / min or less was marked as ◯ (good), and when more than 0.42 g / min, it was marked as x. In the case of 1.6 mm, 0.88 g / min or less was marked as ◎ (very good), 1.4 g / min or less was marked as ◯ (good), and 1.4 g / min or less was marked as x. Those having good welding workability were evaluated for weld metal performance. For the evaluation, a JIS Z 3323 / A1 test piece was collected from all the deposited metals and subjected to a tensile test.
[0044]
  In the comprehensive judgment, “Good” was given for all evaluation items, and “X” was given otherwise. The results are shown in Table 7.
[0045]
[Table 7]

[0046]
  Wire No. which is an example of the present invention. 1 to13Since the total amount of slag agent component and slag agent component, plus the appropriate amount of metal powder component and metal powder total flux is filled in the stainless steel outer shell, welding workability, weld metal tensile test The result was also good. As for spatter generation, wire with low welding currentNo. 12Has a spatter generation rate of 0.35 g / min and a high welding currentNo. 13The spatter generation amount was 0.38 g / min, and the spatter generation amount was not greatly affected by the magnitude of the welding current.
[0047]
  Wire in comparative exampleNo. 14Al₂O_ThreeDue to the large amount, the slag solidified quickly, and the slag did not uniformly encapsulate the beads, resulting in poor bead shape.
[0048]
  WireNo. 15Al₂O_ThreeSince the amount was small, the slag dripped, and the encapsulation and peelability deteriorated. Also, the bead shape was poor. Furthermore, the droplets did not move smoothly and the amount of spatter generated increased.
[0049]
  WireNo. 16Is ZrO₂Because of the large amount, the slag fluidity was poor and the bead shape was poor. Moreover, slag seizure occurred, and slag peelability deteriorated. In addition, the amount of spatter generated increased.
[0050]
  WireNo. 17Is ZrO₂Since the amount was small, the slag was easy to flow, the slag did not uniformly encapsulate the beads, the encapsulating property was deteriorated, and the bead shape was poor. Furthermore, the arc state was unstable and the amount of spatter was increased.
[0051]
  WireNo. 18Slag dripped due to the large amount of metal fluoride, and the encapsulation and bead appearance deteriorated. Furthermore, the arc state was unstable and the amount of spatter was increased.
[0052]
  WireNo. 19Since the amount of metal fluoride is small, the arc state is unstable and the transfer of droplets is not smoothly performed, and the amount of spatter generated increases. Furthermore, the slag peelability was not obtained and the slag peelability deteriorated.
[0053]
  WireNo. 20Had too much potassium compound, the arc state was unstable, and the amount of spatter was increased.
[0054]
  WireNo. 21Since the amount of potassium compound is small, the arc state is unstable and the droplets are not smoothly transferred, and the amount of spatter generated is increased.
[0055]
  WireNo. 22Is X = ([F] + “K”) / [Al when fluorine conversion value [F] and potassium conversion value [K] are used.₂O_Three+ ZrO₂] Required by the formula of slag was deteriorated, the slag encapsulation was deteriorated, and the bead shape was poor.
[0056]
  WireNo. 23Is X = ([F] + “K”) / [Al when fluorine conversion value [F] and potassium conversion value [K] are used.₂O_Three+ ZrO₂Since X obtained by the formula of [2] is small, the arc state is unstable and the amount of spatter generated increases. Furthermore, the slag dripped and the slag encapsulation was deteriorated.
[0057]
  WireNo. 24Causes explosion when droplets are detached from the wire tip because it contains metal carbonate, and Ar—CO is used as the shielding gas.₂Despite the use of, spatter generation increased.
[0058]
  WireNo. 25Since the total amount of nitrogen in the flux and the outer skin is large, the slag stuck to the beads and deteriorated the slag peelability.
[0059]
  WireNo. 26TiO₂The amount of spatter was increased due to the large amount. Furthermore, not only the fluidity of the slag was lowered and the bead shape became poor, but also the temper color was added to the bead surface and the appearance was deteriorated.
[0060]
  WireNo. 27TiO₂Since the amount was small, the arc became unstable and the amount of spatter was increased. Furthermore, the slag encapsulation and peelability were poor, and the bead shape was poor.
[0061]
  WireNo. 28Is SiO₂Since the amount was large, the slag was easy to flow, and it was not uniformly encapsulated in the bead, so that the encapsulating property was deteriorated and the bead shape was poor. Furthermore, the slag was seized and the slag peelability deteriorated.
[0062]
  WireNo. 29Is SiO₂Since the amount was small, the flowability of the slag was poor, the encapsulating property and the peelability were insufficient, and the bead shape was poor.
[0063]
  WireNo. 30Since there are many sodium compounds, slag sticks to a bead and the peelability deteriorated.
[0064]
  WireNo. 31 has less sodium compoundThe amount of spatter increased due to unstable arc conditions.
[0065]
  WireNo. 32Has a large total of slag component, so spatterAmount generatedincreased. Furthermore, since the flux filling rate is high, the arc state is unstable and the amount of spatter generated increases. Furthermore, since the flux filling rate is high, the wire sheath is thin, wire breakage frequently occurs during wire drawing, and the production efficiency of the flux-cored wire is remarkably reduced.
[0066]
  WireNo. 33Because of the large amount of bismuth, slag drooped and a temper color was attached to the bead surface, deteriorating the bead appearance. Furthermore, solidification cracks occurred in the crater portion of the weld bead.
[0067]
  WireNo. 34Since the amount of bismuth is small, the effect of slag removability was not obtained and the slag removability deteriorated.
[0068]
【The invention's effect】
  As described above, the flux-cored wire for stainless steel welding according to the present invention has a stable arc, a small amount of spatter generation, and a bead shape and slag seizure even in high current conditions in stainless steel welding. Further, it is useful as a flux-cored wire for welding stainless steel with excellent slag encapsulation and peelability and good weld metal performance.
[Brief description of the drawings]
FIG. 1 is a diagram showing a relationship between an X value and a spatter generation amount.
FIG. 2 is a cross-sectional view of a flux cored wire.
FIGS. 3A and 3B are explanatory diagrams of a method for measuring the amount of spatter generated, where FIG. 3A is a cross-sectional perspective view, and FIG. 3B is a side view.
[Explanation of symbols]
[0069]
  1 outer skin
  2 Filling flux
  3 seams
  4 test plates
  5 Fixed steel plate
  6 Welding torch
  7 Flux-cored wire
  8 Collection box
  9 Fixing device

Claims (3)

In the stainless steel welding flux cored wire formed by filling the outer shell made of austenitic stainless steel with a flux, the wire diameter is 0.8 to 1.6 mm, and the filling flux is mass% with respect to the total mass of the wire.
Al ₂ O ₃ : 0.1 to 1.6%,
ZrO ₂ : 0.2 to 3.5%,
Metal fluoride (fluorine conversion value): 0.04 to 0.15%,
Potassium compound (calcium conversion value): 0.04 to 0.2% included,
In addition, when the fluorine conversion value [F] and the potassium conversion value [K] are used,
X = ([F] + [K]) / [Al ₂ O ₃ + ZrO ₂ ], and the value of X is
0.025 ≦ X ≦ 0.094 is satisfied,
Metal carbonate: Fill the stainless steel shell with a flux of 0.01% or less 17-26%,
A flux-cored wire for welding stainless steel, characterized in that the total amount of nitrogen in the flux and outer skin is 0.04% or less. % By mass
TiO _2: 0.8~4.0%,
SiO ₂ : 1.1 to 3.8%,
Sodium compound (sodium equivalent value): 0.01 to 0.3% included,
Total slag component: 4.5 to 11.0%
The flux-cored wire for welding stainless steel according to claim 1, wherein   The flux-cored wire for stainless steel welding according to claim 1 or 2, characterized in that it contains one or two kinds of metal bismuth or bismuth oxide in total: 0.005 to 0.1%.

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