JP4896483B2 - Austenitic stainless steel-coated arc welding rod with excellent resistance to Cu embrittlement cracking - Google Patents
Austenitic stainless steel-coated arc welding rod with excellent resistance to Cu embrittlement cracking Download PDFInfo
- Publication number
- JP4896483B2 JP4896483B2 JP2005295799A JP2005295799A JP4896483B2 JP 4896483 B2 JP4896483 B2 JP 4896483B2 JP 2005295799 A JP2005295799 A JP 2005295799A JP 2005295799 A JP2005295799 A JP 2005295799A JP 4896483 B2 JP4896483 B2 JP 4896483B2
- Authority
- JP
- Japan
- Prior art keywords
- welding rod
- stainless steel
- arc welding
- austenitic stainless
- mass
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000003466 welding Methods 0.000 title claims description 74
- 229910000963 austenitic stainless steel Inorganic materials 0.000 title claims description 25
- 238000005336 cracking Methods 0.000 title claims description 21
- 239000011248 coating agent Substances 0.000 claims description 51
- 238000000576 coating method Methods 0.000 claims description 23
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 claims description 18
- 229910052797 bismuth Inorganic materials 0.000 claims description 15
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 239000012535 impurity Substances 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 230000007797 corrosion Effects 0.000 description 50
- 238000005260 corrosion Methods 0.000 description 50
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 24
- 239000002893 slag Substances 0.000 description 24
- 229910052751 metal Inorganic materials 0.000 description 20
- 239000002184 metal Substances 0.000 description 20
- 238000012360 testing method Methods 0.000 description 18
- 239000000463 material Substances 0.000 description 16
- 229910001220 stainless steel Inorganic materials 0.000 description 12
- 230000000694 effects Effects 0.000 description 11
- 239000010935 stainless steel Substances 0.000 description 11
- 229910000831 Steel Inorganic materials 0.000 description 9
- 239000010410 layer Substances 0.000 description 9
- 239000010959 steel Substances 0.000 description 9
- 239000010408 film Substances 0.000 description 8
- 238000005452 bending Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 6
- 238000002844 melting Methods 0.000 description 6
- 229910001566 austenite Inorganic materials 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000010953 base metal Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 238000007711 solidification Methods 0.000 description 4
- 230000008023 solidification Effects 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000013535 sea water Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- OYLGJCQECKOTOL-UHFFFAOYSA-L barium fluoride Chemical compound [F-].[F-].[Ba+2] OYLGJCQECKOTOL-UHFFFAOYSA-L 0.000 description 2
- 229910001632 barium fluoride Inorganic materials 0.000 description 2
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 2
- 238000012790 confirmation Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 229910001610 cryolite Inorganic materials 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- -1 lime carbonate Chemical compound 0.000 description 2
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 2
- 239000001095 magnesium carbonate Substances 0.000 description 2
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 230000004580 weight loss Effects 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010612 desalination reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 229910001651 emery Inorganic materials 0.000 description 1
- 239000010436 fluorite Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 206010022000 influenza Diseases 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 235000012204 lemonade/lime carbonate Nutrition 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910001512 metal fluoride Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- NOTVAPJNGZMVSD-UHFFFAOYSA-N potassium monoxide Inorganic materials [K]O[K] NOTVAPJNGZMVSD-UHFFFAOYSA-N 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 229910000144 sodium(I) superoxide Inorganic materials 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 238000004056 waste incineration Methods 0.000 description 1
Description
本発明は、オーステナイト系ステンレス鋼の被覆アーク溶接棒に関し、特に石炭焚きボイラーやごみ焼却施設の煙突・煙道のような硫酸および塩酸環境、あるいは、海水淡水化プラントや海水熱交換器のような塩化物環境下で使用される高耐食ステンレス鋼の溶接に用いられ、母材と同等の耐食性を有する溶接金属が得られるとともに、耐Ｃｕ脆化割れ性に優れたオーステナイト系ステンレス鋼被覆アーク溶接棒に関する。 The present invention relates to an austenitic stainless steel coated arc welding rod, particularly sulfuric acid and hydrochloric acid environments such as chimneys and flues of coal-fired boilers and waste incineration facilities, or seawater desalination plants and seawater heat exchangers. An austenitic stainless steel-coated arc welding rod used for welding highly corrosion-resistant stainless steel used in a chloride environment, providing a weld metal with corrosion resistance equivalent to that of the base metal and having excellent resistance to Cu embrittlement cracking About.
一般に、耐食性の要求される環境で使用するオーステナイト系ステンレス鋼は、ＪＩＳに規定されているＳＵＳ３０４、非酸化性酸に対する耐食性を向上させる目的にＮｉを増量し、Ｍｏを添加したＳＵＳ３１６、ＳＵＳ３１７、また、硫酸腐食環境下での耐食性を向上させるためにＣｕを適量添加したＳＵＳ３１６Ｊ１(１８Ｃｒ−１２Ｎｉ−２Ｍｏ−２Ｃｕ)、ＳＵＳ３１７Ｊ５Ｌ（２１Ｃｒ−２４．５Ｎｉ−４．５Ｍｏ−１．５Ｃｕ−低Ｃ）などがあり、腐食環境に応じてこれらの鋼種が選択されている。さらに、硫酸環境下での使用を目的としてＣｕが１．０〜３．０％添加されたオーステナイト系ステンレス鋼が知られている（例えば特許文献１および２、参照）。
これらのステンレス鋼の溶接に際しては、溶接金属の耐食性が母材と同等となるように、溶接材料にもＣｕが適量添加されており、Ｃｕを０．５〜１．０％含有した高耐食ステンレス鋼用のＴＩＧおよびプラズマ溶接ワイヤ（例えば特許文献３、参照）、Ｃｕを０．８〜２．４％含有した高耐食ステンレス鋼溶接用フラックス入りワイヤ（例えば特許文献４、参照）、Ｃｕを２．５〜４．５％含有した高耐食ステンレス鋼用溶接ワイヤ（例えば特許文献５、参照）が提案され、ガスシールドアーク溶接に用いられている。
In general, austenitic stainless steel used in an environment where corrosion resistance is required is SUS304 specified in JIS, SUS316, SUS317 added with Mo for the purpose of improving the corrosion resistance against non-oxidizing acid, and SUS317, SUS316J1 (18Cr-12Ni-2Mo-2Cu), SUS317J5L (21Cr-24.5Ni-4.5Mo-1.5Cu-low C) and the like to which an appropriate amount of Cu is added to improve the corrosion resistance in a sulfuric acid corrosion environment Yes, these steel types are selected according to the corrosive environment. Furthermore, an austenitic stainless steel to which Cu is added in an amount of 1.0 to 3.0% for use in a sulfuric acid environment is known (see, for example, Patent Documents 1 and 2).
When welding these stainless steels, an appropriate amount of Cu is added to the welding material so that the corrosion resistance of the weld metal is equivalent to that of the base metal, and high corrosion resistance stainless steel containing 0.5 to 1.0% of Cu. TIG and plasma welding wire for steel (for example, see Patent Document 3), flux-cored wire for high corrosion resistance stainless steel welding containing 0.8 to 2.4% of Cu (for example, see Patent Document 4), Cu for 2 A welding wire for high corrosion resistance stainless steel containing 0.5 to 4.5% (see, for example, Patent Document 5) has been proposed and used for gas shielded arc welding.
一方、例えば、石炭焚きボイラーやごみ焼却施設の煙突・煙道のライニングなどには溶接作業の効率性からガスシールドアーク溶接よりも被覆アーク溶接を用いるのが一般的である。このような用途に適用するために、発明者らは、ステンレス鋼心線または被覆剤の一方もしくは両方に溶接棒全質量に対する質量％で、Ｃｕを０．３〜１．８％含有した高耐食ステンレス鋼用被覆アーク溶接棒（例えば特許文献６、参照）を提案した。しかし、その後の検討の結果、この高耐食ステンレス鋼用被覆アーク溶接棒により得られる溶接金属の耐食性、耐ブローホール性、スラグ剥離性は良好となるが、被覆剤中に含有するＣｕに起因し、溶融境界近傍の溶接熱影響部に微細割れが発生し、溶接部の靱性や疲労強度を低下させるという新たな技術的課題があることが判明した。
Ｃｕを含有したステンレス鋼用被覆アーク溶接棒を製造する場合は、Ｃｕを含有したステンレス鋼心線を用いると製造コストが高くなるため、Ｃｕは少なくとも被覆剤中に含有させ、心線中にはＣｕを全く含有させないか、或いは、Ｃｕ量調整のために含有させる方法が工業的に一般化している。
On the other hand, for example, covering arc welding is generally used rather than gas shielded arc welding because of the efficiency of welding work, for example, for coal-fired boilers and chimney / flue linings of garbage incineration facilities. In order to apply to such a use, the inventors have developed a high corrosion resistance containing 0.3 to 1.8% of Cu in one or both of the stainless steel core wire and the coating material in terms of mass% with respect to the total mass of the welding rod. A coated arc welding rod for stainless steel (for example, see Patent Document 6) has been proposed. However, as a result of subsequent investigations, the corrosion resistance, blowhole resistance, and slag peelability of the weld metal obtained by this coated arc welding rod for high corrosion resistance stainless steel are good, but this is due to the Cu contained in the coating. It has been found that there is a new technical problem in that fine cracks occur in the weld heat-affected zone near the melting boundary and the toughness and fatigue strength of the weld are reduced.
In the case of manufacturing a coated arc welding rod for stainless steel containing Cu, since the manufacturing cost increases when a stainless steel core wire containing Cu is used, Cu is contained in at least the coating agent, A method of not containing Cu at all or adding it for adjusting the amount of Cu is industrially generalized.
しかしながら、発明者らの確認試験の結果によれば、Ｃｕを多量に被覆剤中に含有した被覆アーク溶接棒を用いて溶接する場合には、被覆剤が溶融した後、Ｃｕを含有したスラグが高温の溶接金属および溶接熱影響部を覆うが、Ｃｕはスラグより融点が低いため、スラグが凝固した後も、Ｃｕはスラグ中で溶融状態のまま残留する。この溶融状態のＣｕはスラグから溶接金属および溶接熱影響部のオーステナイト粒界に浸入し、特に溶融線近傍でＣｕ脆化割れを発生させる原因となることがわかった。
このＣｕ脆化割れは溶接部の靱性や疲労強度を低下させるとともに、腐食の起点となるため、母材と同等の機械的特性および耐食性を有する溶接継手が得られるための耐Ｃｕ脆化割れ性に優れた共金系のオーステナイト系ステンレス鋼被覆アーク溶接棒の開発が望まれている。
This Cu embrittlement crack reduces the toughness and fatigue strength of the welded part, and also serves as a starting point for corrosion. Therefore, the Cu embrittlement crack resistance for obtaining a welded joint having mechanical properties and corrosion resistance equivalent to the base metal The development of an excellent austenitic stainless steel-coated arc welding rod with excellent properties is desired.
本発明は、上記の背景技術の問題点に鑑みて、Ｃｕを含有する高耐食オーステナイト系ステンレス鋼用の共金系被覆アーク溶接棒であって、母材と同等の機械的特性および耐食性を有する溶接部が得られるとともに、耐Ｃｕ脆化割れ性に優れたオーステナイト系ステンレス鋼被覆アーク溶接棒を提供することを目的とする。 In view of the problems of the background art described above, the present invention is a co-metal-coated arc welding rod for high corrosion resistance austenitic stainless steel containing Cu, and has mechanical properties and corrosion resistance equivalent to those of a base material. An object of the present invention is to provide an austenitic stainless steel-coated arc welding rod having a welded portion and excellent Cu brittle crack resistance.
本発明は、上記課題を解決するものであって、その要旨とするところは下記の通りである。
（１）オーステナイト系ステンレス鋼心線に被覆剤を被覆塗装してなる被覆アーク溶接棒において、前記被覆剤中に、溶接棒全質量に対する質量％で、Ｃｕ：０．０５〜３．０％を含有し、さらに、
Ｂｉ：０．０５〜０．２％、および、
Ｂｉ2Ｏ3：０．０５〜０．２％のうちの１種または２種をＢｉとＢｉ2Ｏ3の合計含有量が０．２％以下の範囲で含有しており、
更に、前記オーステナイト系ステンレス鋼心線および前記被覆剤のいずれか一方または両方に、溶接棒全質量に対する質量％で、
Ｃ：０．００５〜０．０５％、
Ｓｉ：０．１〜１．６％、
Ｍｎ：０．１〜２．５％、
Ｃｒ：１５．０〜３０．０％、
Ｎｉ：７．５〜２５．０％、
Ｍｏ：０．５〜６．７％、
Ｃｕ：０．０５〜５．０％、
Ｎ：０．０５〜０．３５％を含有し、残部が鉄および不可避的不純物からなることを特徴とするＣｕ脆化割れ性に優れたオーステナイト系ステンレス鋼被覆アーク溶接棒。
The present invention solves the above-mentioned problems, and the gist thereof is as follows.
(1) In a coated arc welding rod formed by coating austenitic stainless steel core wire with a coating agent, Cu: 0.05 to 3.0% in the coating agent in terms of mass% with respect to the total mass of the welding rod. Contains, and
Bi: 0.05-0.2% and
Bi 2 O 3 : One or two of 0.05 to 0.2% are contained within a range where the total content of Bi and Bi 2 O 3 is 0.2% or less ,
Furthermore, in either one or both of the austenitic stainless steel core wire and the coating agent, in mass% with respect to the total mass of the welding rod,
C: 0.005-0.05%,
Si: 0.1 to 1.6%,
Mn: 0.1 to 2.5%
Cr: 15.0-30.0%,
Ni: 7.5-25.0%,
Mo: 0.5 to 6.7%,
Cu: 0.05 to 5.0%,
N: An austenitic stainless steel-coated arc welding rod excellent in Cu embrittlement cracking, characterized by containing 0.05 to 0.35% and the balance being iron and inevitable impurities.
本発明は、高耐食オーステナイト系ステンレス鋼溶接部の健全性が確保される耐Ｃｕ脆化割れ性が優れた被覆アーク溶接棒を容易にかつ安価に提供することを可能としたものであり、本発明の適用により産業の発展に貢献するところは極めて大きい。 The present invention makes it possible to easily and inexpensively provide a coated arc welding rod excellent in Cu embrittlement cracking resistance that ensures the soundness of a high corrosion resistance austenitic stainless steel weld zone. The application of the invention greatly contributes to industrial development.
本発明者らは、被覆剤中にＣｕを添加した種々のオーステナイト系ステンレス鋼被覆アーク溶接棒を試作し、Ｃｕ脆化割れを防止する被覆アーク溶接棒を見いだすことを目的として調査、検討した。その結果、被覆剤中にＢｉまたはＢｉ2Ｏ3を含有させることで、耐Ｃｕ脆化割れ性が改善されることが判明した。
以下、本発明について詳細に説明する。
ステンレス心線に被覆塗装されたＣｕを含有する被覆剤は、溶接アークによって溶融した後、溶接金属中に混入し、溶接金属のＣｕ量を所定の成分に調整される。それとともに、溶融された被覆剤は、溶接金属および溶接熱影響部の表面を覆い、スラグとして凝固することによって、高温の溶接金属および溶接熱影響部を大気から遮断し、酸化および窒化を防止する役割を担う。しかし、被覆剤中にＣｕを多量に含有した被覆アーク溶接棒を用いて溶接する場合には、被覆剤中のＣｕに起因して溶接部の特に溶融線近傍でＣｕ脆化割れを発生させる原因となることがわかった。
The inventors of the present invention have made various types of austenitic stainless steel-coated arc welding rods in which Cu is added to the coating agent, and investigated and examined the purpose of finding a coated arc welding rod that prevents Cu embrittlement cracking. As a result, it was found that Cu embrittlement cracking resistance was improved by including Bi or Bi 2 O 3 in the coating agent.
Hereinafter, the present invention will be described in detail.
The coating agent containing Cu coated on the stainless steel core wire is melted by the welding arc and then mixed in the weld metal, and the Cu amount of the weld metal is adjusted to a predetermined component. At the same time, the melted coating covers the surface of the weld metal and the weld heat affected zone and solidifies as a slag, thereby shielding the hot weld metal and weld heat affected zone from the atmosphere and preventing oxidation and nitridation. Take a role. However, when welding using a coated arc welding rod containing a large amount of Cu in the coating, the cause of Cu embrittlement cracks in the vicinity of the melting line of the weld due to Cu in the coating I found out that
つまり、発明者らの確認試験によれば、スラグは大気と接するスラグ最外層から内面の鋼板方向に向かって凝固するため、分配係数の小さいＣｕはスラグ中の残留液相中に排出されながら凝固が進行し、スラグの最終凝固域である鋼板の表面近傍で薄い膜状となってＣｕは濃化する。さらに、Ｃｕはスラグより融点が低いため、被覆剤が溶融した後、スラグが凝固を完了した時点でも、高温状態の鋼板表面近傍に濃化したＣｕは液相状態で凝固したスラグ中に残留し、このＣｕが溶接部（溶接金属または溶接熱影響部）、特に溶融線近傍の粗大化したオーステナイト粒界に浸入する結果、Ｃｕ脆化割れを発生させることが判明した。 That is, according to the confirmation test by the inventors, slag solidifies from the outermost layer of the slag in contact with the atmosphere toward the steel plate on the inner surface, so that Cu having a small distribution coefficient is solidified while being discharged into the residual liquid phase in the slag. Progresses and becomes a thin film near the surface of the steel sheet, which is the final solidification zone of the slag, and Cu is concentrated. Furthermore, since Cu has a lower melting point than slag, even after the slag is completely solidified after the coating has melted, Cu concentrated in the vicinity of the surface of the steel sheet in the high temperature state remains in the slag solidified in the liquid phase state. It has been found that Cu penetrates into the weld zone (welded metal or weld heat affected zone), in particular, the coarsened austenite grain boundary in the vicinity of the melt line, resulting in Cu embrittlement cracks.
そこで、発明者らは上記メカニズムで発生すると考えられるＣｕ脆化割れの発生を抑制するために、Ｃｕと同様にスラグより融点が低く、かつＣｕより酸素との親和力が強いＢｉに着目した。
一般に、ＢｉまたはＢｉ2Ｏ3は、フラックス入りワイヤによるアーク溶接のフラックス中またはサブマージアーク溶接のフラックス中に添加され、溶接時にスラグの剥離性を向上させる作用があることが知られている。しかし、被覆アーク溶接ではその効果がほとんどないため、一般に、被覆アーク溶接棒の被覆剤中には添加されていない。
Therefore, the inventors focused on Bi, which has a lower melting point than slag and a stronger affinity with oxygen than Cu, in order to suppress the occurrence of Cu embrittlement cracking, which is considered to occur due to the above mechanism.
In general, it is known that Bi or Bi 2 O 3 is added in the flux of arc welding using a flux-cored wire or in the flux of submerged arc welding, and has the effect of improving the slag peelability during welding. However, since there is almost no effect in the covering arc welding, it is generally not added to the covering agent of the covering arc welding rod.
本発明者らは、被覆剤中にＣｕと共にＢｉまたはＢｉ2Ｏ3を添加した被覆アーク溶接棒を作製し、これを用いた溶接試験を行なった。その結果、溶接時に被覆剤が溶融した後、スラグが凝固する段階で、ＣｕおよびＢｉはともに残留液相中に排出されながら凝固が進行するが、Ｃｕより酸素との親和力の強く、かつ鋼板との濡れ性も良好なＢｉは、Ｃｕより先に鋼板表面に酸化膜層を形成し、その上層にＣｕ濃化層が形成されることが判明した。この結果、Ｃｕ濃化層と鋼板表面は、その間に介在するＢｉ酸化膜層によって分断され、高温状態の凝固スラグ中に溶融状態のＣｕが存在しても、Ｃｕ融液が溶接部の粗大化したオーステナイト粒界へ浸入することを抑える作用により、Ｃｕ脆化割れが大幅に防止できることが判明した。 The present inventors made a coated arc welding rod in which Bi or Bi 2 O 3 was added together with Cu in the coating material, and a welding test was performed using this. As a result, after the coating material melts during welding, at the stage where the slag solidifies, both Cu and Bi are solidified while being discharged into the residual liquid phase, but have a stronger affinity for oxygen than Cu and It was found that Bi, which has good wettability, forms an oxide film layer on the steel plate surface prior to Cu, and a Cu concentrated layer is formed thereon. As a result, the Cu enriched layer and the steel plate surface are separated by the Bi oxide film layer interposed between them, and even if Cu in the molten state is present in the solidified slag in the high temperature state, the Cu melt becomes coarse in the welded portion. It has been found that Cu embrittlement cracking can be largely prevented by the action of suppressing entry into the austenite grain boundaries.
本発明は、上記知見に基づいて完成させたものであり、Ｃｕ脆化割れが発生しないためには、被覆剤中にＣｕと共にＢｉまたはＢｉ2Ｏ3を含有することが必要となる。
以下に、本発明のオーステナイト系ステンレス鋼被覆アーク溶接棒中の成分組成の限定理由を述べる。なお、以下に示す「％」は特段の説明がない限り、「質量％」を意味するものとする。また、本発明において、溶接棒全質量に対する質量％とは、下記（Ａ）式で定義されるものを示す。
溶接棒全質量に対する質量％＝心線中の含有％×（１００−被覆率）／１００＋被覆剤中の含有％×被覆率／１００ ・・・（Ａ）
但し、上記「心線中の含有％」は心線全質量に対する心線に含有する成分の質量％、上記「被覆剤中の含有％」は被覆剤全質量に対する被覆剤に含有する成分の質量％を意味し、さらに、上記「被覆率」とは溶接棒全質量に対する被覆剤全質量の占める割合を意味する。
The present invention has been completed based on the above findings, and in order not to cause Cu embrittlement cracking, it is necessary to contain Bi or Bi 2 O 3 together with Cu in the coating agent.
The reasons for limiting the component composition in the austenitic stainless steel-coated arc welding rod of the present invention will be described below. Note that “%” shown below means “% by mass” unless otherwise specified. Moreover, in this invention, the mass% with respect to the welding rod total mass shows what is defined by the following (A) formula.
Mass% with respect to the total mass of the welding rod =% in the core wire × (100−coverage) / 100 +% in the coating agent × coverage / 100 (A)
However, the above-mentioned “% in the core wire” means the mass% of the component contained in the core wire relative to the total mass of the core wire, and the above “% in the coating agent” means the mass of the component contained in the coating agent relative to the total mass of the coating material. Furthermore, the above-mentioned “coverage” means the ratio of the total mass of the coating material to the total mass of the welding rod.
まず、本発明において限定する被覆剤の成分について、以下に説明する。
Ｃｕ：Ｃｕは耐食性を高めるのに顕著な効果があり、特にＮｉ、Ｍｏ、Ｎと共存の形で硫酸環境および塩水環境などで高い耐食性を得るために必須の元素である。溶接棒全質量に対する質量％でＣｕが０．０５％以上で共存添加効果が著しく、３．０％を超えると耐食性は飽和するだけでなく、後述するＢｉ、Ｂｉ2Ｏ3の添加によっても被覆剤中に含有するＣｕ起因の脆化割れを十分に抑制することは困難となる。したがって、その含有量を被覆剤中に溶接棒全質量に対する質量％で、０．０５〜３．０％に限定する。
なお、後述するように被覆剤と心線の両方にＣｕを含有させる場合には、被覆剤中のＣｕ含有量の上限：３．０％を超えないように、心線中にＣｕを更に溶接棒全質量に対する質量％で５．０％含有させることはできる。
また、被覆アーク溶接棒の場合、被覆率は一般的に２５〜５０％であるため、溶接棒全質量に対する質量％でＣｕを０．０５〜３．０％に確保するためには、オーステナイト系ステンレス鋼心線にＣｕを含有しない場合も考慮して、被覆剤中には、被覆剤全質量に対する質量％で、０．１〜１２．０％を含有する必要がある。
First, the components of the coating material limited in the present invention will be described below.
Cu: Cu has a remarkable effect in enhancing corrosion resistance, and is an essential element for obtaining high corrosion resistance particularly in a sulfuric acid environment and a salt water environment in the form of coexistence with Ni, Mo, and N. Co-addition effect is remarkable when Cu is 0.05% or more by mass% with respect to the total mass of the welding rod, and if it exceeds 3.0%, the corrosion resistance is not only saturated but also covered by the addition of Bi and Bi 2 O 3 described later. It becomes difficult to sufficiently suppress the embrittlement crack caused by Cu contained in the agent. Therefore, the content is limited to 0.05 to 3.0% in mass% with respect to the total mass of the welding rod in the coating agent.
As will be described later, when Cu is contained in both the coating agent and the core wire, the upper limit of the Cu content in the coating agent: Cu is further welded in the core wire so as not to exceed 3.0%. It can be made to contain 5.0% by mass% with respect to the total mass of the rod.
In the case of a coated arc welding rod, the coverage is generally 25 to 50%. Therefore, in order to ensure Cu to 0.05 to 3.0% by mass% with respect to the total mass of the welding rod, an austenitic system is used. Considering the case where the stainless steel core wire does not contain Cu, it is necessary that the coating material contains 0.1 to 12.0% by mass% with respect to the total mass of the coating material.
Ｂｉ：Ｂｉは酸素との親和力の強く、鋼板との濡れ性も良好なために、スラグの凝固中ではＣｕより先に鋼板表面に酸化膜層を形成する。このＢｉ酸化膜の上層にＣｕ濃化層が形成されが、Ｂｉ酸化膜層によって溶融したＣｕが鋼板のオーステナイト粒界へ浸入するのを阻止し、割れが防止できる。この割れ防止効果は被覆剤中に溶接棒全質量に対する質量％で０．０５以上を含有すると効果が著しい。一方、被覆剤中のＢｉは溶接金属中にも混入するが、０．２％を超えると、高温割れが発生したり、溶接金属の延性を低下させる。したがって、その含有量を溶接棒全質量に対する質量％で、０．０５〜０．２％に限定する。
なお、通常、オーステナイト系ステンレス鋼心線にはＢｉを含有しないため、被覆率を考慮すると、被覆剤中には、被覆剤全質量に対する質量％で、０．１〜１．０％となる。
Bi: Bi has a strong affinity for oxygen and good wettability with the steel sheet, so that during slag solidification, an oxide film layer is formed on the steel sheet surface prior to Cu. A Cu enriched layer is formed on the upper layer of the Bi oxide film. However, Cu melted by the Bi oxide film layer is prevented from entering the austenite grain boundaries of the steel sheet, and cracking can be prevented. The effect of preventing cracking is remarkable when the coating contains 0.05% or more by mass% based on the total mass of the welding rod. On the other hand, Bi in the coating agent is also mixed in the weld metal, but when it exceeds 0.2%, hot cracking occurs or the ductility of the weld metal is lowered. Therefore, the content is limited to 0.05 to 0.2% by mass% with respect to the total mass of the welding rod.
In general, since Bi is not contained in the austenitic stainless steel core wire, considering the coverage, the coating material has a mass% with respect to the total mass of the coating material and is 0.1 to 1.0%.
Ｂｉ2Ｏ3：Ｂｉ2Ｏ3は被覆剤が溶接アークによって溶融すると、溶融スラグ中では金属Ｂｉ単体となる。その後、スラグの凝固中には上記Ｂｉと同じ挙動を示す。したがって、その含有量を溶接棒全質量に対する質量％で、０．０５〜０．２％に限定する。
上記Ｂｉ及びＢｉ2Ｏ3は、これらのうちの１種または２種を上記範囲で被覆剤中に含有するが、Ｂｉ及びＢｉ2Ｏ3を同時に添加する場合は、高温割れおよび延性低下を防止する観点から、その合計含有量を０．２％以下に制限する。
本発明は、オーステナイト系ステンレス鋼心線と用い、その上記被覆剤中の成分を限定することにより、従来に比べて溶接部の耐Ｃｕ脆化割れ性を十分に向上させることが可能となる。
Bi 2 O 3 : Bi 2 O 3 becomes a metal Bi alone in the molten slag when the coating material is melted by the welding arc. Thereafter, during the solidification of the slag, the same behavior as the Bi is shown. Therefore, the content is limited to 0.05 to 0.2% by mass% with respect to the total mass of the welding rod.
Bi and Bi 2 O 3 contain one or two of them in the above range within the above range, but when Bi and Bi 2 O 3 are added at the same time, hot cracking and ductility reduction are prevented. Therefore, the total content is limited to 0.2% or less.
By using the austenitic stainless steel core wire and limiting the components in the coating agent, the present invention can sufficiently improve the Cu embrittlement crack resistance of the welded portion as compared with the conventional case.
また、本発明は、上記被覆剤中の成分以外に、被覆溶接棒におけるオーステナイト系ステンレス鋼心線および前記被覆剤のいずれか一方または両方に、以下の目的で、さらに、以下の成分を溶接棒全質量に対する質量％で以下の所定範囲で含有させることが好ましい。
Ｃ：Ｃは耐食性に有害であるが、強度の観点から０．００５％以上含有させるのが好ましい。その含有量が０．０５％超では溶接のままの状態および再熱を受けるとＣはＣｒと結合してＣｒ炭化物を析出し、耐粒界腐食性および耐孔食性が著しく劣化するとともに、溶接金属の靱性、延性が著しく低下するため、その含有量を０．０５％以下に限定した。
Ｓｉ：Ｓｉは脱酸元素およびスラグの剥離性を良くする元素として添加されるが、０．１％未満ではその効果が十分でなく、一方、その含有量が１．６％超では延性低下に伴い、靱性が大きく低下するとともに、溶接時の溶融溶込みも減少し、実用溶接上の問題になる。したがって、その含有量を０．１〜１．６％に限定した。
In addition to the components in the above-mentioned coating agent, the present invention further includes the following components for welding rods in the one or both of the austenitic stainless steel core wire and the above-mentioned coating agent in the coated welding rod. It is preferable to contain in the following predetermined ranges by mass% with respect to the total mass.
C: C is harmful to corrosion resistance, but is preferably contained in an amount of 0.005% or more from the viewpoint of strength. If its content exceeds 0.05%, it will remain in the welded state and when it is reheated, C will combine with Cr to precipitate Cr carbide, which significantly deteriorates the intergranular corrosion resistance and pitting corrosion resistance. Since the toughness and ductility of the metal are significantly reduced, the content is limited to 0.05% or less.
Si: Si is added as a deoxidizing element and an element improving the slag releasability, but if it is less than 0.1%, the effect is not sufficient, while if its content exceeds 1.6%, the ductility decreases. Along with this, the toughness is greatly reduced and the melt penetration during welding is reduced, which becomes a problem in practical welding. Therefore, the content is limited to 0.1 to 1.6%.
Ｍｎ：Ｍｎは脱酸元素として添加するが、その含有量が０．１％未満では効果が十分でなく、一方、２．５％を越えて添加すると延性が低下するのでその含有量を０．１〜２．５％に限定した。
Ｃｒ：Ｃｒはオーステナイト系ステンレス鋼の主要元素として不働態皮膜を形成し耐食性の向上に寄与する。このため、１５．０％以上含有させる必要がある。一方、Ｃｒ含有量が多いほど海水環境下での耐孔食性は向上するが、シグマ相などの脆い金属間化合物が析出しやすくなるため靱性が低下し、また、ワイヤ製造性が低下するとともに製造コストも高くなるため、その含有量の上限を３０．０％とした。
Mn: Mn is added as a deoxidizing element, but if its content is less than 0.1%, the effect is not sufficient. On the other hand, if it exceeds 2.5%, the ductility is lowered, so its content is reduced to 0. Limited to 1-2.5%.
Cr: Cr forms a passive film as a main element of austenitic stainless steel and contributes to improvement of corrosion resistance. For this reason, it is necessary to make it contain 15.0% or more. On the other hand, the greater the Cr content, the better the pitting corrosion resistance in the seawater environment, but the brittle intermetallic compounds such as the sigma phase are likely to precipitate, resulting in decreased toughness and reduced wire manufacturability. Since the cost increases, the upper limit of the content is set to 30.0%.
Ｎｉ：Ｎｉは中性塩環境や非酸化性の硫酸環境での腐食に対し、顕著な抵抗性を与え、かつ、不働態皮膜を強化するため、Ｎｉ含有量は多いほど耐食性に有効である。また、Ｎｉはオーステナイト生成元素でありオーステナイト系ステンレス鋼の主要元素として、オーステナイト相を生成・安定にする。このため、７．５％以上含有させる必要がある。しかしながら、Ｎｉは高価な元素であり、多量添加は製造コストが高くなるため、その含有量の上限を２５．０％とした。
Ｍｏ：Ｍｏは不働態皮膜を安定化して高い耐食性を得るのに極めて有効な元素であり、その効果を十分に得るために０．５％以上含有させるのが好ましい。特に塩化物環境での耐孔食性向上は顕著であるが、その含有量が６．７％を越えるとシグマ相など脆い金属間化合物を生成して溶接金属の靱性が低下するため、６．７％以下に制限する。
Ni: Ni gives remarkable resistance to corrosion in a neutral salt environment or a non-oxidizing sulfuric acid environment, and strengthens the passive film. Therefore, the higher the Ni content, the more effective the corrosion resistance. Ni is an austenite-forming element, and as a main element of austenitic stainless steel, austenite phase is generated and stabilized. For this reason, it is necessary to make it contain 7.5% or more. However, Ni is an expensive element, and the addition of a large amount increases the production cost, so the upper limit of its content was made 25.0%.
Mo: Mo is an element that is extremely effective in stabilizing the passive film and obtaining high corrosion resistance, and is preferably contained in an amount of 0.5% or more in order to sufficiently obtain the effect. In particular, the improvement of pitting corrosion resistance in a chloride environment is remarkable. However, if its content exceeds 6.7%, brittle intermetallic compounds such as a sigma phase are formed and the toughness of the weld metal is lowered. % Or less.
Ｃｕ：Ｃｕは上記の通り、耐食性を高めるのに顕著な効果があり、特にＮｉ、Ｍｏ、Ｎと共存の形で硫酸環境および塩水環境などで高い耐食性を得るために必須の元素である。０．０５％以上で共存添加効果が著しくなるが、５．０％を超えると耐食性は飽和するとともに延性が低下するため、その含有量は０．０５〜５．０％に限定した。なお、上述したように被覆剤と心線の両方にＣｕを含有させる場合には、被覆剤中のＣｕ含有量の上限：３．０％を超えないように、心線中にＣｕを更に溶接棒全質量に対する質量％で５．０％まで含有させても、上述したＢｉ、Ｂｉ2Ｏ3の添加作用によって被覆剤中に含有するＣｕ起因の脆化割れを十分に抑制することができる。 Cu: As described above, Cu has a significant effect on enhancing corrosion resistance, and is an essential element for obtaining high corrosion resistance particularly in a sulfuric acid environment and a salt water environment in the form of coexistence with Ni, Mo, and N. The coexistence additive effect becomes remarkable at 0.05% or more, but when it exceeds 5.0%, the corrosion resistance is saturated and the ductility is lowered, so the content is limited to 0.05 to 5.0%. In addition, when Cu is contained in both the coating agent and the core wire as described above, Cu is further welded in the core wire so as not to exceed 3.0% of the Cu content in the coating agent. Even if it is contained up to 5.0% by mass% with respect to the total mass of the rod, embrittlement cracking due to Cu contained in the coating agent can be sufficiently suppressed by the above-described addition action of Bi and Bi 2 O 3 .
Ｎ：Ｎは強力なオーステナイト生成元素であり、塩化物環境下での耐孔食性を向上させるため、０．０５％以上含有させるのが好ましい。含有量が多いほどその効果は大きいが、０．３５％を超えて添加すると、窒化物が多量析出して延性を低下させるとともに、ブローホールが発生しやすくなるため、その含有量は０．３５％以下に限定した。
本発明では、オーステナイト系ステンレス鋼被覆アーク溶接棒として、上述のように成分含有量を規定した溶接棒を用いてオーステナイト系ステンレス鋼を溶接することにより、Ｃｕ脆化割れが発生せず、母材と同等の機械的特性および耐食性を有する溶接部が得られる。
なお、本発明の被覆アーク溶接棒の被覆剤中には、溶接中にＣＯ２ガスを発生して溶接金属を大気から遮断することを目的に、炭酸石灰、炭酸バリウム、炭酸マグネシウムなどの金属炭酸塩、良好なスラグ流動性を確保することを目的に、蛍石、氷晶石、弗化バリウムなどの金属弗化物、およびアーク状態を良好に保つ目的に、ＳｉＯ２、ＴｉＯ２、ＮａＯ２、Ｋ２Ｏなどの金属酸化物が含まれる。
N: N is a strong austenite-forming element, and is preferably contained in an amount of 0.05% or more in order to improve the pitting corrosion resistance in a chloride environment. The greater the content, the greater the effect, but if added over 0.35%, a large amount of nitride precipitates to lower the ductility and blow holes are more likely to occur, so the content is 0.35. % Or less.
In the present invention, as an austenitic stainless steel-coated arc welding rod, by welding the austenitic stainless steel using the welding rod with the specified content as described above, Cu embrittlement cracking does not occur, and the base metal A weld having mechanical properties and corrosion resistance equivalent to the above is obtained.
In the coating agent for the coated arc welding rod of the present invention, a metal carbonate such as lime carbonate, barium carbonate, magnesium carbonate is used for the purpose of generating CO2 gas during welding and shielding the weld metal from the atmosphere. In order to ensure good slag fluidity, metal fluorides such as fluorite, cryolite and barium fluoride, and metals such as SiO2, TiO2, NaO2 and K2O in order to maintain a good arc state Oxides are included.
以下、実施例にて本発明を説明する。
表１に成分を示すオーステナイト系ステンレス鋼（板厚６．０ｍｍ）を母材として、開先角度６０°、ルート面1ｍｍの開先を作成した。また、表２に成分を示す供試心線に表３の成分の被覆剤（但し、表３の表示は、溶接棒全体に対する質量％である。）を同じく表３に示す被覆率にて被覆塗装して、表４に示す被覆アーク溶接棒を作成した。即ち、表４に示される成分値は、（表２に示す心線の化学成分値）×（１００−被覆率）／１００＋（表３の成分値）で求められる。なお、表３中のその他のスラグ剤は、炭酸バリウム、炭酸マグネシウム、氷晶石、弗化バリウム、ＮａＯ2、Ｋ2Ｏ、ＣａＯ、ＦｅＯ、Ａｌ2Ｏ3などであり、これらの合計含有量を示した。溶接方法は、棒径３．２ｍｍの溶接棒を用い、溶接電流１００〜１４０Ａ、アーク電圧２０〜２５Ｖ、溶接速度１０〜２０ｃｍ／ｍｉｎで下向き溶接を行った。
Hereinafter, the present invention will be described with reference to examples.
A groove with a groove angle of 60 ° and a root surface of 1 mm was prepared using austenitic stainless steel (sheet thickness: 6.0 mm) having the components shown in Table 1 as a base material. In addition, the test cords showing the components shown in Table 2 are coated with the coating agents of the components shown in Table 3 (however, the indication in Table 3 is mass% with respect to the entire welding rod) at the coverage shown in Table 3 . The coated arc welding rod shown in Table 4 was prepared by painting. That is, the component values shown in Table 4 can be obtained by (chemical value of core wire shown in Table 2) × (100−coverage) / 100 + (component value in Table 3). The remaining slag agent in Table 3, barium carbonate, magnesium carbonate, cryolite, barium fluoride, and the like NaO 2, K 2 O, CaO , FeO, Al 2 O 3, the total content of these showed that. As the welding method, a welding rod having a rod diameter of 3.2 mm was used, and downward welding was performed at a welding current of 100 to 140 A, an arc voltage of 20 to 25 V, and a welding speed of 10 to 20 cm / min.
次に、それぞれの溶接継手から、ＪＩＳ Ｚ ３１２２に規定の表曲げ試験片を採取し、Ｒ＝２ｔ、曲げ角度１８０°で欠陥の有無を調査した。また、それぞれの溶接部の表層より溶接金属と溶接熱影響部の両方を含む腐食試験片を採取し、各種腐食試験を実施した。硫酸腐食性試験では、厚さ：３ｍｍ、幅：３０ｍｍ、長さ：３０ｍｍの試験片の全面を６００番エメリー紙で湿式研磨、脱脂後、４０℃の５０％硫酸溶液中に６時間浸漬し、浸漬前後の重量を測定して腐食減量を評価した。孔食試験では、４０℃の３．５％ＮａＣｌ溶液中にて孔食電位の測定をＪＩＳ Ｇ ０５７７に規定される方法に準拠して実施した。 Next, from each welded joint, a surface bending specimen specified in JIS Z 3122 was sampled, and the presence or absence of defects was investigated at R = 2t and a bending angle of 180 °. In addition, corrosion test pieces including both the weld metal and the weld heat affected zone were collected from the surface layer of each weld and various corrosion tests were performed. In the sulfuric acid corrosion test, the entire surface of the test piece having a thickness of 3 mm, a width of 30 mm, and a length of 30 mm was wet-polished with No. 600 emery paper, degreased, and immersed in a 50% sulfuric acid solution at 40 ° C. for 6 hours. The weight loss before and after immersion was measured to evaluate the corrosion weight loss. In the pitting corrosion test, the pitting corrosion potential was measured in a 3.5% NaCl solution at 40 ° C. according to the method specified in JIS G 0577.
表５に、曲げ試験結果、硫酸腐食試験結果、孔食試験結果を示す。曲げ試験結果は、溶接長さ２０ｃｍ当たりの溶融線近傍の割れ個数を示す。なお、発生した割れについては、断面検鏡を行い、これらの割れがＣｕ脆化割れであることを確認した。また、孔食試験結果は、電流密度：１００ｍＡ／ｃｍ2の時の電位を示し、孔食電位の○印は、孔食は発生せず水の電気分解により酸素が発生したものを示す。 Table 5 shows the bending test results, the sulfuric acid corrosion test results, and the pitting corrosion test results. The bending test result indicates the number of cracks in the vicinity of the fusion line per 20 cm weld length. In addition, about the crack which generate | occur | produced, the cross-sectional examination was performed and it confirmed that these cracks were Cu embrittlement cracks. The pitting corrosion test result shows the potential at a current density of 100 mA / cm 2 , and the ◯ mark of the pitting corrosion potential indicates that no pitting corrosion occurred and oxygen was generated by electrolysis of water.
表５において、本発明例の記号１〜記号６は、被覆剤中のＣｕ含有量に関わらず、表曲げ試験において割れは確認されず、耐Ｃｕ脆化割れ性に優れていることがわかる。また、硫酸腐食試験および孔食電位測定においても良好な結果が得られている。一方、比較例の記号７〜記号１１は、ＢｉまたはＢｉ2Ｏ3が被覆剤中に添加されていないため、本発明の効果は発揮されず、表曲げ試験において、多数の割れが発生し、これらの割れはＣｕ脆化割れであることも確認された。また、記号７、記号８、記号１０、記号１１の被覆剤処方は、それぞれ、本発明の記号１、記号３、記号４、記号６の被覆剤よりＢｉまたはＢｉ2Ｏ3のみを削除したものであり、表４の溶接棒の成分では、Ｂｉ以外は同一成分であるのに関わらず、孔食電位が低下している。これは、上述の通りＣｕ脆化割れが起こっているため、これらが腐食の起点となったためである。また、記号９は、記号８とＣｕ以外はほぼ同一成分であるが、Ｃｕが本発明範囲より少ないため、著しい硫酸腐食が発生している。記号１２は、被覆剤中にＢｉおよびＢｉ2Ｏ3が含まれているため、表曲げ試験では割れは発生せず、耐Ｃｕ脆化割れ性は優れているが、ＢｉおよびＢｉ2Ｏ3添加量が本発明範囲より多いため、溶接中に凝固割れが発生している。 In Table 5, it can be seen that the symbols 1 to 6 of the present invention example are excellent in resistance to Cu embrittlement cracking, regardless of the Cu content in the coating material, without cracking in the surface bending test. Good results have also been obtained in sulfuric acid corrosion tests and pitting potential measurements. On the other hand, since the symbols 7 to 11 of the comparative example are not added Bi or Bi 2 O 3 in the coating agent, the effect of the present invention is not exhibited, and a number of cracks occur in the surface bending test. These cracks were also confirmed to be Cu embrittlement cracks. Further, the coating formulations of symbol 7, symbol 8, symbol 10, and symbol 11 are obtained by deleting only Bi or Bi 2 O 3 from the coating agents of symbol 1, symbol 3, symbol 4, and symbol 6 of the present invention, respectively. In the components of the welding rod shown in Table 4, the pitting corrosion potential is lowered regardless of the same components except Bi. This is because Cu embrittlement cracking has occurred as described above, and these have become starting points of corrosion. Symbol 9 is substantially the same component except for symbol 8 and Cu, but since sulfuric acid is less than the scope of the present invention, significant sulfuric acid corrosion occurs. No. 12 shows that Bi and Bi 2 O 3 are contained in the coating material, so that no cracking occurs in the surface bending test and Cu brittle crack resistance is excellent, but Bi and Bi 2 O 3 are added. Since the amount is larger than the range of the present invention, solidification cracks are generated during welding.
Claims (1)
Ｂｉ：０．０５〜０．２％、および、
Ｂｉ2Ｏ3：０．０５〜０．２％のうちの１種または２種をＢｉとＢｉ2Ｏ3の合計含有量が０．２％以下の範囲で含有しており、
更に、前記オーステナイト系ステンレス鋼心線および前記被覆剤のいずれか一方または両方に、溶接棒全質量に対する質量％で、
Ｃ：０．００５〜０．０５％、
Ｓｉ：０．１〜１．６％、
Ｍｎ：０．１〜２．５％、
Ｃｒ：１５．０〜３０．０％、
Ｎｉ：７．５〜２５．０％、
Ｍｏ：０．５〜６．７％、
Ｃｕ：０．０５〜５．０％、
Ｎ：０．０５〜０．３５％を含有し、残部が鉄および不可避的不純物からなることを特徴とするＣｕ脆化割れ性に優れたオーステナイト系ステンレス鋼被覆アーク溶接棒。 In the coated arc welding rod formed by coating the austenitic stainless steel core wire with a coating agent, the coating agent contains Cu: 0.05 to 3.0% by mass% with respect to the total mass of the welding rod, further,
Bi: 0.05-0.2% and
Bi 2 O 3 : One or two of 0.05 to 0.2% are contained within a range where the total content of Bi and Bi 2 O 3 is 0.2% or less ,
Furthermore, in either one or both of the austenitic stainless steel core wire and the coating agent, in mass% with respect to the total mass of the welding rod,
C: 0.005-0.05%,
Si: 0.1 to 1.6%,
Mn: 0.1 to 2.5%
Cr: 15.0-30.0%,
Ni: 7.5-25.0%,
Mo: 0.5 to 6.7%,
Cu: 0.05 to 5.0%,
N: An austenitic stainless steel-coated arc welding rod excellent in Cu embrittlement cracking, characterized by containing 0.05 to 0.35% and the balance being iron and inevitable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005295799A JP4896483B2 (en) | 2005-10-11 | 2005-10-11 | Austenitic stainless steel-coated arc welding rod with excellent resistance to Cu embrittlement cracking |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005295799A JP4896483B2 (en) | 2005-10-11 | 2005-10-11 | Austenitic stainless steel-coated arc welding rod with excellent resistance to Cu embrittlement cracking |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2007105734A JP2007105734A (en) | 2007-04-26 |
| JP4896483B2 true JP4896483B2 (en) | 2012-03-14 |
Family
ID=38031996
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005295799A Active JP4896483B2 (en) | 2005-10-11 | 2005-10-11 | Austenitic stainless steel-coated arc welding rod with excellent resistance to Cu embrittlement cracking |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4896483B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5182652B2 (en) | 2007-04-13 | 2013-04-17 | 住友大阪セメント株式会社 | Nickel-iron-zinc alloy nanoparticles |
| CN103817458A (en) * | 2012-11-16 | 2014-05-28 | 李彬 | High-chromium welding rod |
| CN117506230B (en) * | 2024-01-05 | 2024-03-15 | 成都工业学院 | Welding rod core wire and wear-resistant surfacing welding electrode |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3441821B2 (en) * | 1994-12-12 | 2003-09-02 | 新日本製鐵株式会社 | Covered arc welding rod for austenitic stainless steel |
| JP3854553B2 (en) * | 2002-08-14 | 2006-12-06 | 新日鐵住金ステンレス株式会社 | Flux-cored wire for austenitic stainless steel with excellent sulfuric acid corrosion resistance, pitting corrosion resistance, ductility and toughness |
-
2005
- 2005-10-11 JP JP2005295799A patent/JP4896483B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007105734A (en) | 2007-04-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6809533B2 (en) | Flux-cored wire, welded joint manufacturing method, and welded joint | |
| JP4566899B2 (en) | High strength stainless steel welding flux cored wire | |
| WO2012105452A1 (en) | Ni-BASED HIGH-CR ALLOY WIRE FOR WELDING, ROD FOR ARC-SHIELDED WELDING, AND METAL FOR ARC-SHIELDED WELDING | |
| JP6719217B2 (en) | Stainless steel flux cored wire | |
| KR102154217B1 (en) | Welded structural members | |
| JP2010110817A (en) | Low-hydrogen coated electrode | |
| KR20180108731A (en) | Flux cored wire, method of manufacturing weld joint, and weld joint | |
| WO2017154122A1 (en) | Flux-cored wire, weld joint manufacturing method and weld joint | |
| CN106392369B (en) | Ni-based alloy flux-cored wire | |
| JP6390204B2 (en) | Flux-cored wire for gas shielded arc welding | |
| JP2017507027A (en) | Welding materials for heat-resistant steel | |
| JP5410039B2 (en) | Stainless steel flux cored wire for electrogas arc welding | |
| JP2019025524A (en) | Flux-cored wire for gas-shielded arc welding, and manufacturing method of welded joint | |
| JP6953931B2 (en) | Flux-cored wire for gas shielded arc welding and welding joint manufacturing method | |
| JP2018192520A (en) | Flux-cored wire for gas shield arc welding, and manufacturing method of weld joint | |
| JP5830278B2 (en) | Submerged arc welding method for low alloy steel with excellent sulfuric acid resistance and hydrochloric acid resistance | |
| JP4896483B2 (en) | Austenitic stainless steel-coated arc welding rod with excellent resistance to Cu embrittlement cracking | |
| JP2008126279A (en) | Flux-cored wire for gas shielded arc welding | |
| JP4874064B2 (en) | Non-consumable electrode type metal cored wire for welding | |
| WO2017154754A1 (en) | Welded metal and welded structure containing said welded metal | |
| JP2019025525A (en) | Flux-cored wire for gas-shielded arc welding, and manufacturing method of welded joint | |
| JP2019042782A (en) | Gas shield arc-welding flux-cored wire and manufacturing method of welding joint | |
| JP7215911B2 (en) | Flux-cored wire for gas-shielded arc welding | |
| JP3930782B2 (en) | Coated arc welding rod for welding low alloy steel with excellent sulfuric acid resistance and hydrochloric acid resistance | |
| JP6953930B2 (en) | Flux-cored wire for gas shielded arc welding and welding joint manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080711 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20110118 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110125 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110225 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20111220 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20111221 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4896483 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150106 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R371 | Transfer withdrawn |
Free format text: JAPANESE INTERMEDIATE CODE: R371 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |