JPH02229693A - Coated electrode for enclosed arc welding of rail - Google Patents
Coated electrode for enclosed arc welding of railInfo
- Publication number
- JPH02229693A JPH02229693A JP5065089A JP5065089A JPH02229693A JP H02229693 A JPH02229693 A JP H02229693A JP 5065089 A JP5065089 A JP 5065089A JP 5065089 A JP5065089 A JP 5065089A JP H02229693 A JPH02229693 A JP H02229693A
- Authority
- JP
- Japan
- Prior art keywords
- welding
- rail
- slag
- welding rod
- less
- 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.)
- Granted
Links
- 238000003466 welding Methods 0.000 title claims abstract description 152
- 239000000463 material Substances 0.000 claims abstract description 41
- 239000011248 coating agent Substances 0.000 claims abstract description 33
- 238000000576 coating method Methods 0.000 claims abstract description 32
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N titanium dioxide Inorganic materials O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 12
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 11
- 229910001512 metal fluoride Inorganic materials 0.000 claims abstract description 10
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 8
- 229910052720 vanadium Inorganic materials 0.000 claims description 8
- 150000004649 carbonic acid derivatives Chemical class 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 abstract description 29
- 229910001562 pearlite Inorganic materials 0.000 abstract description 12
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 abstract description 4
- 230000007547 defect Effects 0.000 abstract description 4
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 abstract description 3
- 229910001634 calcium fluoride Inorganic materials 0.000 abstract description 3
- 239000002893 slag Substances 0.000 description 54
- 229910052751 metal Inorganic materials 0.000 description 52
- 239000002184 metal Substances 0.000 description 52
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 27
- 229910000831 Steel Inorganic materials 0.000 description 19
- 239000010959 steel Substances 0.000 description 19
- 229910045601 alloy Inorganic materials 0.000 description 10
- 239000000956 alloy Substances 0.000 description 10
- 230000000694 effects Effects 0.000 description 9
- 210000001015 abdomen Anatomy 0.000 description 6
- 238000005336 cracking Methods 0.000 description 6
- 238000004132 cross linking Methods 0.000 description 6
- 230000007423 decrease Effects 0.000 description 6
- 229910000734 martensite Inorganic materials 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 230000009466 transformation Effects 0.000 description 6
- 229910052804 chromium Inorganic materials 0.000 description 5
- 229910052758 niobium Inorganic materials 0.000 description 5
- 229910000851 Alloy steel Inorganic materials 0.000 description 4
- 239000010953 base metal Substances 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 230000006378 damage Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000000670 limiting effect Effects 0.000 description 3
- 238000007711 solidification Methods 0.000 description 3
- 230000008023 solidification Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000005552 hardfacing Methods 0.000 description 2
- 235000012204 lemonade/lime carbonate Nutrition 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 241000282342 Martes americana Species 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical group [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- ORUIBWPALBXDOA-UHFFFAOYSA-L magnesium fluoride Chemical compound [F-].[F-].[Mg+2] ORUIBWPALBXDOA-UHFFFAOYSA-L 0.000 description 1
- 229910001635 magnesium fluoride Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000011775 sodium fluoride Substances 0.000 description 1
- 235000013024 sodium fluoride Nutrition 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Nonmetallic Welding Materials (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は鉄道レールまたはクレーンレールを突合わせ溶
接又は肉盛溶接する際に用いる被覆アーク溶接棒に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coated arc welding rod used for butt welding or overlay welding of railway rails or crane rails.
第１図はレールの断面を示し、１は足部．２は腹部，３
は頭部，４は頭表面である。従来からレールを突合せ溶
接または肉盛溶接するには、接合レール端面を開先加工
して逐次多層溶接する方法、あるいはＩ型開先で突合わ
せた後レール足部１を多Ｎ溶接し、その後腹部２と頭部
３をエンクローズド当金材で取り囲み、連続的に溶接す
るエンクローズドアーク溶接法が用いられている。また
、レールの肉盛溶接には突合せ溶接部のレール頭表面４
を硬化肉盛したり、レールの局部的な表面班または摩耗
部分を肉盛補修する方法がある。Figure 1 shows a cross section of the rail, with 1 indicating the foot section. 2 is the abdomen, 3
is the head, and 4 is the head surface. Conventionally, butt welding or overlay welding of rails has been carried out by groove-forming the joint rail end faces and sequentially performing multi-layer welding, or by welding the rail foot 1 with multiple N after welding with an I-shaped groove, and then An enclosed arc welding method is used in which the abdomen 2 and the head 3 are surrounded by an enclosed metal material and continuously welded. In addition, for overlay welding of rails, the rail head surface 4 of the butt weld part
There is a method of hardfacing the rail or repairing local surface spots or worn parts of the rail.
レールはその使用目的から頭表面では車輪とのころがり
接触に対する耐摩耗性と疲労亀裂に対する抵抗力、すな
わち耐疲労損傷性の大きい性質が要求されている。一方
、足部と腹部では車輪通過時の衝撃あるいは曲げ荷重に
耐え得るだけの静的強度と疲労強度が必要とされており
、さらに溶接割れ等の溶接欠陥についても皆無または実
用的にさしつかえない程度以下に極力少なくなっていな
ければならない。Due to the intended use of the rail, the head surface of the rail is required to have high wear resistance against rolling contact with wheels and resistance to fatigue cracks, that is, high resistance to fatigue damage. On the other hand, the legs and abdomen need to have sufficient static strength and fatigue strength to withstand the impact or bending load caused by passing wheels, and there are no or practically no weld defects such as weld cracks. It must be as low as possible.
現在世界の鉄道用普通レールの化学成分は第１表に示す
ように重量％でＣ ： ０． ４ ０〜０．８２％，Ｓ
ｉ ： ０．０ ５〜０．３ ５％， Ｍｎ： ０．６
０〜１．２ ５％を含有しており、その金属組織はバ
ーライトで、引張り強さは７０ｋｇ／一以上である。As shown in Table 1, the chemical composition of ordinary railway rails in the world is currently C: 0. 4 0-0.82%, S
i: 0.05~0.35%, Mn: 0.6
It contains 0 to 1.25%, its metal structure is barlite, and its tensile strength is 70 kg/1 or more.
最近、レール使用性能に関する研究は多く、耐摩耗性と
疲労損傷性はバーライト組織が最も優れ、マルテンサイ
ト組織は有害で、同じパーライト組織であれば硬さが大
きくＣ含有量の多い方が優れていることが明らかにされ
ている。Recently, there has been a lot of research on the performance of rails in use.The barlite structure has the best wear resistance and fatigue damage resistance, while the martensite structure is harmful, and if it is the same pearlite structure, the one with higher hardness and higher C content is better. It has been made clear that
これらの性能をさらに高めるため前記の普通レールの頭
表部または全体を熱処理した硬頭レールまたは前記普通
レールの成分にＳｆ：１．Ｏ％以下、Ｍｎ ： １．
５％以下まで高めさらにＣｒ， Ｎｔ， Ｍｏ， Ｖ
，Ｎｂ， Ｃｕのうち１種または２種以上でＣｒ：１．
３％以下、Ｎｉ： ２．０％以下、ＭｏまたはＶ ：
０． ３％以下、Ｎｂ ： ０． １％以下、Ｃｕ ：
０． ３％以下添加した合金鋼レールおよび両方を併
用した合金鋼熱処理レールが実用化されている。In order to further improve these performances, Sf: 1. 0% or less, Mn: 1.
Increase to 5% or less and further increase Cr, Nt, Mo, V
, Nb, and Cu, and Cr: 1.
3% or less, Ni: 2.0% or less, Mo or V:
0. 3% or less, Nb: 0. 1% or less, Cu:
0. Alloy steel rails with 3% or less added and alloy steel heat-treated rails that use a combination of both have been put into practical use.
従来、レールを突合せ溶接または肉盛溶接する際に用い
られる被覆アーク溶接捧は第２表に示すようにＪＩＳＺ
３２１３低合金高張力鋼用被覆アーク溶接棒である。Conventionally, covered arc welding strips used when butt welding or overlay welding of rails are JISZ compliant as shown in Table 2.
3213 is a coated arc welding rod for low-alloy high-strength steel.
これらの溶接棒は通常厚鋼板等に使用されるため、ＪＩ
ＳＺ３５０３被覆アーク溶接棒心線用線材またはＪＩＳ
Ｇ３５０５軟鋼線材で定められるＣ ： ０． ２ ５
％以下、Ｍｎ：０．６５％以下の線材にＮｉ， Ｃｒお
よびＭｏの１種または２種以上の合金成分剤を含有する
フラックスを被覆したものである。従って、このような
溶接捧をレールに適用した場合に形成される溶接金属は
Ｃ ： ０． ３％以下で、Ｓｉ， Ｍｎの他にＮｉ，
Ｃｒ， Ｍｏの１種または２種以上を０．１％以上含
有する。このためレール母材の溶融境界部近傍に高温割
れが発生する。この高温割れはレール鋼の溶融点が約１
４７０゜Ｃであるのに対し、溶接金属はそれより高く約
１５３０”Ｃであるために理論的に避けられない。さら
にこの溶融境界部近傍には溶接のままで多量のマルテン
サイト組織を生成し、疲労強度が著しく低下するので、
通常溶接後７１０゜Ｃ以下の温度で焼き戻しまたは焼き
なましをしなければならない。These welding rods are usually used for thick steel plates, etc., so JI
SZ3503 coated arc welding rod core wire rod or JIS
C defined for G3505 mild steel wire rod: 0. 2 5
% or less, Mn: 0.65% or less is coated with a flux containing one or more alloy components of Ni, Cr, and Mo. Therefore, the weld metal formed when such a welded stud is applied to a rail has a C: 0. 3% or less, in addition to Si and Mn, Ni,
Contains 0.1% or more of one or more of Cr and Mo. As a result, hot cracks occur near the melting boundary of the rail base material. This hot cracking occurs when the melting point of rail steel is approximately 1
470°C, whereas the temperature of the weld metal is higher than that, approximately 1530"C, so it is theoretically unavoidable. Furthermore, a large amount of martensitic structure is generated near this fusion boundary while welding. , as the fatigue strength decreases significantly.
Normally, after welding, it must be tempered or annealed at a temperature below 710°C.
その結果、溶接金属の組織は耐摩耗性の低い焼き戻しマ
ルテンサイトを生成するため、前記の溶接棒を用いたレ
ールの溶接部はたとえ硬さが母材レ一ルと同じでも溶接
金属層が局部的に早期に摩耗する。このような高温割れ
および局部摩耗は母材レールが高Ｃで合金鋼化すなわち
高強度化すればするほど顕著になり、高強度レールにお
いては実際に溶接不能の状態になっていた。As a result, the structure of the weld metal produces tempered martensite with low wear resistance, so the weld metal layer of the rail welded using the above-mentioned welding rod is the same even if the hardness is the same as that of the base metal rail. Localized premature wear. Such hot cracking and local wear become more pronounced as the base material rail is made of alloy steel with a higher C content, that is, the higher the strength is increased, and in fact, high strength rails have become unweldable.
またレールの肉盛溶接法には第２表で示すようなＪＩＳ
Ｚ３２５１硬化肉盛用被覆アーク溶接棒のＤＦ２Ａまた
はＯＦ２Ｂに該当する溶接棒が用いられている。In addition, for the rail overlay welding method, JIS standards as shown in Table 2 are used.
A welding rod corresponding to DF2A or OF2B of Z3251 coated arc welding rod for hardfacing is used.
ＤＦ２Ａに該当する溶接棒は前記低合金高張力鋼用溶接
棒とほとんど変わらないので、前記の問題がそのまま当
てはまる， ＤＦ２Ｂで形成される溶接金属は溶接のま
まではマルテンサイト組織を生成するので、溶接後焼き
戻し処理を施さざるを得ない。このため、溶接金属は焼
き戻しマルテンサンド組織となってパーライト組織が得
られないだけでなく、熱処理レールではこのような後熱
処理をすると、この熱影響を受ける母材レール頭表部が
軟化し、かえって摩耗が著しくなるという事態が発生し
ていた。Welding rods corresponding to DF2A are almost the same as the welding rods for low-alloy high-strength steel, so the above-mentioned problems apply as is.Weld metal formed with DF2B produces a martensitic structure when welded, so it is difficult to weld. It is necessary to perform post-tempering treatment. For this reason, not only does the weld metal become a tempered marten sand structure and a pearlite structure cannot be obtained, but when heat-treated rails are subjected to such post-heat treatment, the head surface of the base rail, which is affected by this heat, becomes soft. On the contrary, a situation occurred in which the wear became significant.
本発明者らは広範囲な研究を行った結果、第２表に示す
ような従来の被覆アーク溶接棒によって形成された溶着
金属は母材レールと著しく異なった成分となるため前記
のような問題が発生することを知見し、溶着金属が従来
溶接には不適当とされてきた母材レールと類似の高Ｃ型
パーライト組織となる高炭素含有被覆アーク溶接棒組成
を見いだした。又一方溶接作業性の面からみると、高炭
素含有被覆アーク溶接棒はスラグ流動性、耐ブローホー
ル性が劣化することは良く知られている。As a result of extensive research, the inventors of the present invention have found that the weld metal formed by conventional coated arc welding rods as shown in Table 2 has a composition significantly different from that of the base metal rail, which causes the above-mentioned problems. They found that a high carbon-containing coated arc welding rod has a composition in which the deposited metal has a high C-type pearlite structure similar to that of the base material rail, which has traditionally been considered unsuitable for welding. On the other hand, from the viewpoint of welding workability, it is well known that coated arc welding rods containing high carbon content deteriorate slag fluidity and blowhole resistance.
特に本発明に見られるように、レール腹部をエンクロー
ズド当余材で取り囲み連続的に溶接するエンクローズア
ーク溶接では、安定したスラグ流動性、適正なスラグ発
生量およびアーク安定性が健全な溶接継手を得る上で重
要となる。本発明者らは、被覆アーク溶接棒の合金組成
およびスラグ生成剤の検討を行い、本発明をなしえたも
のである。In particular, as seen in the present invention, in enclosed arc welding, in which the rail abdomen is surrounded by an enclosed extra material and continuously welded, stable slag fluidity, appropriate slag generation amount, and sound arc stability result in a healthy welded joint. This is important in obtaining the The present inventors studied the alloy composition of the coated arc welding rod and the slag forming agent, and were able to accomplish the present invention.
本発明の要旨は、重量％でＣ：１．０〜１．５％を含有
する心線の外周に炭酸塩の１種又は２種以上を４２〜５
５％、金属フッ化物の１種又は２種以上を１３〜２３％
、ルチール＝０．５〜９．５％、被覆剤中のＣａＯ／Ｃ
ａＦｚの比が１．２〜１．８の範囲にある被覆剤が溶接
棒全重量に対して１５〜３２％被覆され、かつ溶接棒全
重量％でＣ ： ０． ６ ５〜１．５％、Ｓｔ ：
０． ２ 〜２． ２％、Ｍｎ ： ０． ６ 〜２．
５％または上記の他にＣｒ：１．３％以下、ＭＯ又は
■は０． ３％以下、Ｎｂ ： ０． １％以下、Ｎｉ
：２．Ｏ％以下、Ｃｕ ： ０． ３％以下の１．種又
は２種以上を含有することを特徴とするレールのエンク
ローズアーク溶接用被覆アーク溶接棒にある。The gist of the present invention is that one or more carbonates are added to the outer periphery of a core wire containing C: 1.0 to 1.5% by weight at 42 to 5%.
5%, 13-23% of one or more metal fluorides
, Rutile = 0.5-9.5%, CaO/C in coating material
The coating material having an aFz ratio in the range of 1.2 to 1.8 covers 15 to 32% of the total weight of the welding rod, and C: 0. 6 5-1.5%, St:
0. 2 ~2. 2%, Mn: 0. 6-2.
5% or in addition to the above, Cr: 1.3% or less, MO or ■ is 0. 3% or less, Nb: 0. 1% or less, Ni
:2. 0% or less, Cu: 0. 1. Less than 3%. A covered arc welding rod for enclosed arc welding of rails is characterized by containing one or more species.
以下本発明のレールのエンクローズアーク溶接用被覆ア
ーク溶接棒の限定理由について詳細に説明する。The reasons for limiting the covered arc welding rod for enclosed arc welding of rails according to the present invention will be explained in detail below.
高炭素含有被覆アーク溶接棒を設計するにあたり、硬鋼
心線を用いた理由として
■ 高炭素溶着金属が安定して得られる、■ 溶接作業
性特に溶接スラグの流動性が安定する、
など軟綱心線に比べ硬鋼心線が優れている理由による。When designing a high carbon-containing coated arc welding rod, the reasons for using a hard steel core wire are: ■ High carbon weld metal can be stably obtained, ■ Welding workability, especially the fluidity of welding slag, is stable, etc. This is because hard steel core wire is superior to core wire.
高炭素溶着金属を得るには、被覆剤より炭素を添加する
方法が簡便かつ低コストな方法として一般的である。し
かしこの方法は溶接条件や施工条件により炭素の溶着金
属に対する歩留が変化したり、又、被覆剤の欠け落ちな
どにより炭素量は変化することもあり、安定した炭素量
を得ることは難かしい。しかも被覆剤中の炭素添゛加量
が増加すればする程この傾向は顕著となる。In order to obtain a high carbon weld metal, it is common to add carbon to the coating material as a simple and low cost method. However, with this method, the yield of carbon relative to the deposited metal changes depending on welding and construction conditions, and the amount of carbon changes due to chipping of the coating material, etc., making it difficult to obtain a stable amount of carbon. . Moreover, this tendency becomes more pronounced as the amount of carbon added to the coating material increases.
一方、高炭素含有心線を用い心線より添加する方法は歩
留も良く、溶着金属の炭素量は安定することはよく知ら
れているが、本発明者らは溶接作業性の改善においても
高炭素含有伸線の使用が有利であることを以下の如くし
て確かめた。即ち、本発明者らは、スラグ流動性の改善
をスラグ組成の検討と同時に心線の化学組成によるアー
ク力の違いに着目し検討を行い第２図の知見を得た。即
ち、得られる各溶着金属の炭素量が同一組成になるよう
に調整された溶接棒において心線中の炭素，酸素量によ
り棒先端のスラグのからみ度合が異なることを見出した
．
第２図はレーザ背光シェリレーン観察装置を用いて溶接
時の棒先端にスラグがからむ時間と溶接時間との割合を
架橋率として求め、溶着金属のＣ量との関係で整理した
ものである。この試験結果により、同一炭素量の溶着金
属を得るには、高炭素含有心線の方が架橋率（スラグの
からみ）が少ないことがわかり、溶接作業性の面からも
高炭素含有心線の使用が有利であることがわかった。し
かしながら心線中の炭素含有量が１．０％未満では被覆
剤からの炭素添加量が増えると同時に、レーザ背光シュ
リレーン観察装置を用い架橋率を測定した結果も悪く棒
先端にスラグがからむなど溶接作業性が劣化するので好
ましくない。一方心線中の炭素含有量が１．５％超では
、心線加工中において伸線性に欠け線材の硬化が激しく
焼鈍回数が増加するなど生産性の面で問題がある。よっ
て溶接作業性，線材の加工性を考慮し心線中の炭素量を
１．０〜１．５％と規定した。On the other hand, it is well known that the method of using a high carbon content core wire and adding it from the core wire has a good yield and stabilizes the amount of carbon in the weld metal. The advantage of using drawn wire with high carbon content was confirmed as follows. That is, the present inventors studied the improvement of slag fluidity by focusing on the difference in arc force depending on the chemical composition of the core wire as well as the slag composition, and obtained the findings shown in FIG. 2. In other words, it was found that in welding rods that were adjusted so that the carbon content of each weld metal was the same, the degree of entanglement of the slag at the tip of the rod differed depending on the amount of carbon and oxygen in the core wire. Figure 2 shows the ratio of the time during which slag gets entangled with the rod tip during welding to the welding time using a laser backlit Sherley lane observation device, and is calculated as the crosslinking rate, and is organized in relation to the C content of the weld metal. The test results show that in order to obtain weld metal with the same carbon content, a high carbon content core wire has a lower crosslinking rate (slag entanglement), and from the viewpoint of welding workability, a high carbon content core wire has a lower crosslinking rate (slag entanglement). The use was found to be advantageous. However, if the carbon content in the core wire is less than 1.0%, the amount of carbon added from the coating material will increase, and at the same time, the results of measuring the crosslinking rate using a laser-backlit Shurilane observation device will be poor, such as slag entangled at the tip of the rod, etc. This is not preferable because workability deteriorates. On the other hand, if the carbon content in the core wire exceeds 1.5%, there are problems in terms of productivity, such as poor wire drawability and severe hardening of the wire during processing. Therefore, in consideration of welding workability and wire workability, the carbon content in the core wire was determined to be 1.0 to 1.5%.
次に被覆剤の限定理由について述べる。Next, the reason for limiting the coating material will be described.
？ず炭酸塩（ここでいう炭酸塩とは、炭酸石灰，炭酸バ
リウム，炭酸マグネシウムをいう）は、溶接時にＣＯｔ
ガスを発生し、溶融プールを大気より保護し、ビット，
ブローホールの発生防止、アーク安定性およびスラグ剥
離性の改善に効果がある。? Carbonates (carbonates here refer to lime carbonate, barium carbonate, and magnesium carbonate) are COt during welding.
Generates gas, protects the molten pool from the atmosphere, and protects the bit,
Effective in preventing blowholes and improving arc stability and slag removability.
又、スラグ粘性調整などにも効果は著しく、溶接材料の
設計には重要な原材料として使用されている。しかし、
炭酸塩１種又は２種以上が４２％未満では溶接棒先端の
保護筒が適正に生成されずシールド効果の劣化を招き、
アーク安定性が悪化してスパッタの発生が多くなり好ま
しくない。又、５５％を超えると過大にＣＯ■ガスが発
生しスパッタ量が増加すると共にスラグ量が多くなり、
且っスラグ粘性が過大となる。It is also extremely effective in adjusting slag viscosity, and is used as an important raw material in the design of welding materials. but,
If the content of one or more carbonates is less than 42%, a protective tube at the tip of the welding rod will not be formed properly, leading to deterioration of the shielding effect.
This is undesirable because arc stability deteriorates and spatter increases. Moreover, if it exceeds 55%, excessive CO gas is generated, the amount of spatter increases, and the amount of slag increases.
In addition, the slag viscosity becomes excessive.
特にスラグ量およびスラグ粘性が増加することはエンク
ローズアーク溶接用の溶接棒としては、溶接作業性の面
で大きな障害となる。In particular, an increase in the amount of slag and slag viscosity poses a major obstacle in terms of welding workability when used as a welding rod for enclosed arc welding.
レール腹部を当金材で取り囲み連続的に溶接するエンク
ローズアーク溶接では、溶接スラグの挙動が健全な溶接
金属を得るために重要な因子となる． ＨｒＩち、アー
ク安定性を損わない程度のスラグ量とシールド効果を維
持し、がっ、スラグの粘性を低く抑えアーク直下より円
滑に溶接スラグを溶接プール後方に排除することが必要
であり、溶接棒先端にスラグがからむ状態になるとアー
クが遮断されアーク切れを起し健全な溶接作業が行われ
ず、従って健全な溶接金属は得られない。これらの理由
により炭酸塩の１種又は２種以上を４２〜５５％と規定
した。In enclosed arc welding, in which the rail belly is surrounded by a metal material and continuously welded, the behavior of the welding slag is an important factor in obtaining a sound weld metal. It is necessary to maintain the amount of slag and shielding effect to an extent that does not impair arc stability, and to keep the viscosity of slag low and to smoothly expel welding slag from directly below the arc to the rear of the welding pool. If the tip of the welding rod becomes entangled with slag, the arc will be interrupted and arc breakage will occur, making it impossible to perform sound welding work and, therefore, unable to obtain sound weld metal. For these reasons, the content of one or more carbonates was defined as 42 to 55%.
次に金属フッ化物（ここでいう金属フッ化物とは、フッ
化カルシウム、フッ化ソーダ、フッ化マグネシウムをい
う）については、スラグの粘性，流動性の調整、および
保護筒の生成に効果がある．しかし金属フッ化物の１種
又は２種以上が１３％未満ではスラグ粘性が過大となり
、溶接棒先端にスラグがからみ安定した溶接ができない
。一方、２３％を超えると、スラグ量が増加すると同時
にスラグ粘性が極度に低下し、溶接プール前方にスラグ
が回り込み、安定した溶接作業ができない．これらの理
由により金属フッ化物の１種又は２種以上を１３〜２３
％と規定した。Next, metal fluorides (here, metal fluoride refers to calcium fluoride, sodium fluoride, and magnesium fluoride) are effective in adjusting the viscosity and fluidity of slag, and forming a protective shell. ．． However, if the content of one or more metal fluorides is less than 13%, the slag viscosity becomes excessive, and the tip of the welding rod becomes entangled with the slag, making stable welding impossible. On the other hand, if it exceeds 23%, the slag amount increases and at the same time the slag viscosity decreases extremely, causing the slag to wrap around the front of the welding pool, making it impossible to perform stable welding work. For these reasons, one or more metal fluorides are used in
%.
ルチールについてはスラグの粘性を良好に保ち、アーク
の安定性の改善に効果は大きい。しかし、０．５％未満
ではその効果はなく、スパッタの発生が多く好ましくな
い。又９．５％を超えるとスラグの粘性が過大となり溶
接棒先端にスラグがからむなど安定した溶接作業ができ
ないことからルチールを０． ５〜９．５％と規定した
。Rutile is highly effective in maintaining good slag viscosity and improving arc stability. However, if it is less than 0.5%, there is no such effect and a large amount of spatter occurs, which is not preferable. If the rutile exceeds 9.5%, the viscosity of the slag becomes excessive and the tip of the welding rod becomes entangled with the slag, making stable welding impossible. It was defined as 5 to 9.5%.
次に被覆剤中のＣａＯ／ＣａＦｚｏ比を１． ２ 〜１
． ８の範囲に限定した理由について述べる。Next, the CaO/CaFzo ratio in the coating material was set to 1. 2 ~1
．． The reason for limiting the range to 8 will be explained below.
本発明者らは、レールのエンクローズアーク溶接におい
て、被覆剤中の主成分である炭酸石灰，フッ化カルシウ
ム，ルチールと溶接作業性との関係を調査した。その結
果第３図に示す知見を得た。The present inventors investigated the relationship between lime carbonate, calcium fluoride, and rutile, which are the main components in the coating, and welding workability in enclosed arc welding of rails. As a result, the findings shown in FIG. 3 were obtained.
被覆剤中のＣａＯとＣａＦ．の比と、ルチールとの関係
において被覆剤の軟化点が大きく影響されることが分か
る。又、その結果、エンクローズアーク溶接における溶
接作業性の優劣も支配されることが判明した。即ち、被
覆剤中のＣａＯ／ＣａＦｔの比が１．２未満ではスラグ
の粘性が高《、溶接プール近傍から円滑にスラグが排除
されず、溶接棒先端に溶接スラグがからむなど溶接作業
性は好ましくない。CaO and CaF in the coating material. It can be seen that the softening point of the coating material is greatly influenced by the relationship between the ratio of rutile and rutile. As a result, it has also been found that the welding workability in enclosed arc welding is also controlled. That is, if the ratio of CaO/CaFt in the coating material is less than 1.2, the viscosity of the slag is high, and the welding workability is unfavorable, such as the slag not being smoothly removed from the vicinity of the welding pool and the tip of the welding rod becoming entangled with the welding slag. do not have.
又ＣａＯ／ＣａＦｚの比が１．８を超えると、溶接スラ
グの粘性が高くなると同時にスラグ発生量が多くなり、
健全な溶接ができない。これらの理由により被覆剤中の
ＣａＯ／ＣａＰｚＯ比を１． ２ 〜１． ８と規定し
た。Furthermore, when the CaO/CaFz ratio exceeds 1.8, the viscosity of welding slag increases and at the same time, the amount of slag generated increases.
Sound welding cannot be performed. For these reasons, the CaO/CaPzO ratio in the coating material is set to 1. 2 ~1. 8.
尚、ここでいう被覆剤の軟化点とは、粉砕した溶接スラ
グを２Ｍｎ巾Ｘ ３ ［ ｔの形状にプレスし、固めた
試料を大気炉中で加熱し、その試料が溶融し、元の試料
の高さの１／２になった時の温度をその被覆剤の軟化点
と規定した。The softening point of the coating material here refers to the temperature at which crushed welding slag is pressed into a shape of 2Mn width x 3 [t, the solidified sample is heated in an atmospheric furnace, and the sample melts and returns to the original sample. The temperature at which the height of the coating material reached 1/2 was defined as the softening point of the coating material.
次に被覆剤を溶接棒全重量に対して１５〜３２％塗布す
る理由について述べる。Next, the reason why the coating material is applied in an amount of 15 to 32% based on the total weight of the welding rod will be described.
（１）式で示す計算式により求めた値、すなわち被覆率
が１５％未満では安定したシールド効果が奏されず、ま
たアークを発生するために必要な溶接棒先端の保護筒の
強度が低くなり、溶接途中で欠け落ち、安定した溶接が
出来ない。又、溶接棒製造時に被覆の厚さが薄いために
円滑な塗布ができない。一方被覆率が３２％を超えると
、スラグ量が増加し溶接スラグが溶融プール上に留まり
安定した溶接ができないことから溶接棒全重量に対する
被覆剤の量を１５〜３２％と規定した．Ｆｗ：被覆剤重
量
Ｒｗ：心線重量
次に溶接棒全重量に対する合金成分量を規定した理由に
ついて述べる。If the value calculated using formula (1), that is, the coverage ratio is less than 15%, a stable shielding effect will not be achieved, and the strength of the protective tube at the tip of the welding rod, which is necessary to generate an arc, will decrease. , it will chip off during welding, making stable welding impossible. Moreover, when the welding rod is manufactured, the thickness of the coating is so thin that smooth application cannot be achieved. On the other hand, if the coverage exceeds 32%, the amount of slag increases and the welding slag remains on the molten pool, making stable welding impossible. Therefore, the amount of coating agent relative to the total weight of the welding rod was specified as 15 to 32%. Fw: Coating material weight Rw: Core wire weight Next, the reason for specifying the amount of alloy components relative to the total weight of the welding rod will be described.
Ｃは溶着金属にレール鋼と類似のパーライト組織を生成
させるための必須成分であると同時に、溶着金属を高炭
素成分系、すなわちＣ ： ０． ４〜１．０％に調整
して、この凝固温度をレール鋼とほぼ同等にすることに
よって、従来技術で発生していた母材レールの溶融境界
層における高温液化割れを防止するもので本発明の最大
の特徴をなすものである。更に、溶着金属のＣ含有量が
増加するに従い継手引張り強さおよび硬さが増加するた
め溶接金属の対摩耗性および耐疲労損傷性を向上させる
ことができる。溶接棒全重量に対するＣ含有量が０．６
５％未満では溶着金属のＣ量が０． ４％未満となる場
合が生じ、母材レールの溶融境界層に高温割れが発生す
ると共に溶着金属のパーライト組織が少なくなり、継手
引張り強さの７０ｋｇ／一以上が得られない。一方被覆
アーク溶接棒のＣ含有量が１．５％を超えると溶着金属
のＣ量が１．０％超となり、溶接金属に初析セメンタイ
トが析出し、溶接金属が著しく脆化する。又溶接作業性
の面においてもスラグの粘性が低下し、溶接プールの前
方（溶接方向）に回り込み溶接棒先端にからみ円滑な溶
接ができないことから、溶接棒全重量に対するＣｉＥを
０．６５〜１．５％と規定した。C is an essential component for producing a pearlite structure similar to that of rail steel in the weld metal, and at the same time makes the weld metal a high carbon component system, that is, C: 0. By adjusting the solidification temperature to 4 to 1.0% and making this solidification temperature almost the same as that of rail steel, the present invention prevents high-temperature liquefaction cracking in the molten boundary layer of the base rail that occurred in the conventional technology. This is the biggest feature of Furthermore, as the C content of the weld metal increases, the joint tensile strength and hardness increase, so the wear resistance and fatigue damage resistance of the weld metal can be improved. C content based on the total weight of the welding rod is 0.6
If it is less than 5%, the C content of the weld metal will be 0. In some cases, it becomes less than 4%, hot cracking occurs in the molten boundary layer of the base rail, and the pearlite structure of the weld metal decreases, making it impossible to obtain a joint tensile strength of 70 kg/1 or more. On the other hand, if the C content of the coated arc welding rod exceeds 1.5%, the C content of the deposited metal will exceed 1.0%, pro-eutectoid cementite will precipitate in the weld metal, and the weld metal will become extremely brittle. In addition, in terms of welding workability, the viscosity of the slag decreases, and it wraps around the front of the welding pool (in the welding direction) and gets entangled with the tip of the welding rod, making it impossible to weld smoothly. It was defined as .5%.
Ｓｉは通常溶着金属の脱酸剤として含有されるものであ
るが、必要に応じてその量をコントロールし溶着金属中
のＳｉ含有量を０． １〜１．０％の範囲に入れるよう
にする．レール鋼のＳｔ含有量は通常０，１％以上であ
り、Ｓｉはパーライト組織においてフエライトを強化し
て強度を上昇させると同時に耐疲労損傷性を向上させ、
さらにパーライト変態の開始時間，温度におよぼす影響
が小さいため溶着金属のＳｉ量がレール鋼より多く含有
されていても１．０％以下であれば有害にはならない。Si is normally contained as a deoxidizing agent for weld metal, but its amount may be controlled as necessary to reduce the Si content in weld metal to 0. Try to keep it within the range of 1 to 1.0%. The St content of rail steel is usually 0.1% or more, and Si strengthens ferrite in the pearlite structure to increase strength and improve fatigue damage resistance.
Furthermore, since the effect on the start time and temperature of pearlite transformation is small, even if the weld metal contains more Si than the rail steel, it will not be harmful as long as it is 1.0% or less.
これらの理由により溶接棒全重量に対して０．２％未満
ではレール鋼のＳｔ含有量を下廻り、脱酸効果も十分で
なく、プロホール，ピットなどが発生する。又、２．２
％を超えると溶着金属のＳｔ含有量が１．０％超となり
、継手性能が劣化すると同時に溶接作業性においてもス
ラグ粘性過多となり、安定した溶接ができなくなること
から溶接棒全重量に対するＳｔ量をを０．２〜２．２％
と規定した。For these reasons, if the St content is less than 0.2% based on the total weight of the welding rod, the St content will be lower than that of rail steel, the deoxidizing effect will not be sufficient, and proholes, pits, etc. will occur. Also, 2.2
If it exceeds 1.0%, the St content of the weld metal will exceed 1.0%, which will deteriorate the joint performance and increase the slag viscosity in terms of welding workability, making stable welding impossible. 0.2-2.2%
stipulated.
ＭｎはＳｔと同様溶着金属の脱酸剤として添加される。Like St, Mn is added as a deoxidizing agent for the deposited metal.
レール鋼のＭｎ含有量は０．６％以上であり、Ｍｎはパ
ーライト変態を遅滞させる元素であって添加量によりパ
ーライトの変態の開始が変化し強度も変化するので、溶
着金属のＭｎ含有量はレール鋼とほぼ対応したものでな
ければならない。溶接捧全重量に対するＭｎ量が０．
６％未満では溶着金属のＭｎ量が低くなり、溶着金属の
引張り強さまたは伸び、すなわち延性が低下する。溶接
棒全重量に対するＭｎｆｆｉが２．５％を超えると溶着
金属のＭｎ量が増加し、溶接金属中に形成されたマルテ
ンサイトをバーライトに変態させる後熱処理が著しく困
難となることから溶接棒全重量に対するＭａｉｌを０．
６〜２．５％と規定した。The Mn content of the rail steel is 0.6% or more, and Mn is an element that retards pearlite transformation, and depending on the amount added, the start of pearlite transformation changes and the strength also changes, so the Mn content of the weld metal is It must be approximately compatible with rail steel. The amount of Mn relative to the total weight of the welding tribute is 0.
If it is less than 6%, the amount of Mn in the weld metal becomes low, and the tensile strength or elongation, that is, ductility, of the weld metal decreases. If Mnffi exceeds 2.5% based on the total weight of the welding rod, the amount of Mn in the weld metal will increase, making it extremely difficult to perform post-heat treatment to transform martensite formed in the weld metal into barlite. Mail for weight is 0.
It was defined as 6-2.5%.
母材レールが前記Ｃ， Ｓｉ， Ｍｎの他にＣｒ， Ｍ
ｏ， Ｖ，Ｎｂ， Ｃｕのうち１種または２種以上含
有す名場合には、溶着金属にもこれらの合金成分を母材
レールと同等もしくはそれ以下の量だけ含有しなければ
ならない場合がある。すなわち、Ｃｒ， Ｍｏ， Ｖ
はＭｎと同様パーライト変態を遅滞させる元素であって
、添加量によりパーライト変態の開始が変化し強度も変
化するので、母材レールがこれらの合金成分を含有する
合金鋼である場合には、すくなくともレール頭頂面に用
いる被覆アーク溶接棒にもこれらの合金成分を含有して
いないと、溶接ままで、または溶接後の熱処理によって
、母材レールと類似の金属組織，硬さおよび継手引張り
強さが得られない。従って被覆アーク溶接棒のＣｒ，
Ｍｏ， Ｖ含有量はＣｒ：１．３％以下、Ｍｏ，Ｖ：
０．３％以下にする。The base material rail is made of Cr, M in addition to the above C, Si, and Mn.
If the weld metal contains one or more of O, V, Nb, and Cu, the weld metal may also have to contain these alloy components in an amount equal to or less than that of the base metal rail. . That is, Cr, Mo, V
Like Mn, Mn is an element that retards pearlite transformation, and the start of pearlite transformation changes depending on the amount added, and the strength also changes. Therefore, if the base rail is an alloy steel containing these alloy components, at least If the coated arc welding rod used for the top surface of the rail does not contain these alloy components, the metallographic structure, hardness, and joint tensile strength similar to that of the base material rail will be achieved during welding or through heat treatment after welding. I can't get it. Therefore, the Cr of the coated arc welding rod,
Mo, V content is Cr: 1.3% or less, Mo, V:
Keep it below 0.3%.
Ｎｂはバーライト変態の終了時間を大幅に短縮させる元
素であるため、溶接後の冷却中に有害なマルテンサイト
が生成するのを防止する効果がある。Since Nb is an element that significantly shortens the completion time of barlite transformation, it has the effect of preventing harmful martensite from being generated during cooling after welding.
しかし溶着金属のＮｂ含有量が０． １％を超えると巨
大な炭・窒化物を生じ、靭性，疲労強度を低下させるの
で、被覆アーク溶接棒のＮｂ含有量は０．１％以下とす
る。However, the Nb content of the weld metal is 0. If the Nb content exceeds 1%, huge carbon/nitrides are formed and the toughness and fatigue strength are reduced, so the Nb content of the coated arc welding rod is set to 0.1% or less.
Ｃｕはレール鋼の耐食性を向上するのに効果のある合金
成分であり、耐食性レールには０．３％以下含有される
。従って、耐食性レールの溶接には溶着金属にも０．３
％以下のＣｕを含有しないと母材レールと同様の耐食性
が得られない。しかし溶着金属のＣｕ含有量が０．３％
超では、熱間脆性を起こし表面疵が発生するので、被覆
アーク溶接棒のＣｕ含有量は０． ３％以下とする。Cu is an alloy component that is effective in improving the corrosion resistance of rail steel, and is contained in a corrosion-resistant rail in an amount of 0.3% or less. Therefore, for welding corrosion-resistant rails, the weld metal must also be 0.3
% or less, corrosion resistance similar to that of the base material rail cannot be obtained. However, the Cu content of the weld metal is 0.3%.
If the Cu content of the coated arc welding rod is 0.0, the Cu content of the coated arc welding rod is 0.0. 3% or less.
Ｎｉはレール鋼の延性または靭性を向上する合金成分で
あるが、レール鋼はもともと延性または靭性が低くても
使用可能な鋼材であるため、レールに添加する場合は少
ない。しかし溶着金属が２． ０％以下含有すると溶接
部の延性または靭性が向上するので、溶着金属にＮｉを
添加する必要のある場合がある。しかし溶着金属がＮｉ
を２．０％を超えて含有すると、溶着金属に高温凝固割
れが発生しやすくなるので、被覆アーク溶接棒のＮｉ含
有量は２，０％以下とする。Ni is an alloy component that improves the ductility or toughness of rail steel, but since rail steel is a steel material that can be used even if it has low ductility or toughness, it is rarely added to rails. However, the weld metal is 2. If Ni is contained in an amount of 0% or less, the ductility or toughness of the weld zone will improve, so it may be necessary to add Ni to the weld metal. However, the weld metal is Ni.
If the Ni content exceeds 2.0%, high-temperature solidification cracking tends to occur in the deposited metal, so the Ni content of the coated arc welding rod should be 2.0% or less.
以上詳述したように、本発明の被覆アーク溶接捧を用い
、通常の溶接条件のもとてレール鋼に対して突合せ溶接
，肉盛溶接を行っても、高温割れ等の溶接欠陥が発生す
ることな《施工でき、溶接後適切な後熱処理を組み合わ
せることにより有害組織がな《母材レールと同等の硬さ
とバーライト組織を有する溶接継手を得ることができる
。As detailed above, even if butt welding and overlay welding are performed on rail steel using the covered arc welding strip of the present invention under normal welding conditions, welding defects such as hot cracking will occur. By combining appropriate post-welding heat treatment after welding, it is possible to obtain a welded joint with no harmful structures and a barite structure and hardness equivalent to that of the base rail.
以下に実施例によって本発明の効果をさらに具体的に説
明する。The effects of the present invention will be explained in more detail below using Examples.
以下本発明の実施例を示す。 Examples of the present invention will be shown below.
第３表にエンクローズアーク溶接用被覆アーク溶接棒を
示す。棒寸法は全て５．０φＸ４５０ｍｍとした。Table 3 shows coated arc welding rods for enclosed arc welding. All rod dimensions were 5.0φX450mm.
第４表に使用したレール母材を示す。又、溶接条件は直
流逆極性溶接電流２２０Ａで溶接した。Table 4 shows the rail base materials used. The welding conditions were a DC reverse polarity welding current of 220A.
溶接に際して、溶接施工開始時点でレール足部の開先面
を４００から５ ０ ０ ’Ｃに予熱し、溶接完了後レ
ール断面全周を均等に加熱する多孔ノズルバーナを用い
て８００〜１０００゜Ｃに加熱し放冷した。During welding, the groove surface of the rail foot is preheated to 400 to 500°C at the start of welding work, and then heated to 800 to 1000°C using a multi-hole nozzle burner that evenly heats the entire circumference of the rail cross section after welding is complete. It was heated and allowed to cool.
第５表に試験結果を示す。溶接作業性はスラグ発生量の
多少．棒先端へのスラグのからみ，又、スパッタ発生量
の多少を観察し、実用上あまり問題とならないものには
○、実用上問題となるものについては×と評価した。溶
着金属の割れについては溶接中央部の縦断面マクロ試験
片を採取し、研磨後力ラーチェック．検鏡により割れの
有無を確認をした。Table 5 shows the test results. Welding workability is determined by the amount of slag generated. The entanglement of the slag with the tip of the rod and the amount of spatter generated were observed, and those that did not pose much of a practical problem were evaluated as ○, and those that were a practical problem were evaluated as ×. For cracks in the weld metal, take a longitudinal cross-sectional macro specimen at the center of the weld and check it after polishing. The presence or absence of cracks was confirmed using a microscope.
本発明例で示した棒記号Ｅ−１〜Ｅ−１０については、
溶接作業性も十分実用可能であり、かつ溶着金属および
熱影響部にも割れは認められず実用可能な継手性能が得
られた。Regarding the bar symbols E-1 to E-10 shown in the examples of the present invention,
The welding workability was sufficient for practical use, and no cracks were observed in the weld metal or the heat-affected zone, resulting in practical joint performance.
一方、比較例で示したＥ−１１は被覆率が高く、スラグ
発生量の増加，スラグ流動性の劣化およびスパッタ発生
の増加などがあり、溶接作業性が悪く、又Ｓｉ， Ｍｎ
が低いことなどからブローホールの発生も見られた。On the other hand, E-11 shown in the comparative example has a high coverage rate, which causes an increase in the amount of slag generation, deterioration of slag fluidity, and increase in spatter generation, and has poor welding workability.
The occurrence of blowholes was also observed due to the low
Ｅ−１２は被覆率が高く、ルチール量が上限を超えてい
ることがらＥ−１１と同様の溶接作業性を示した。又溶
接棒成分のＳｉ量が高《、Ｍｎ量が低いことから熱影響
部に微細な割れが認められた。E-12 had a high coverage and the amount of rutile exceeded the upper limit, so it exhibited welding workability similar to E-11. Furthermore, due to the high Si content and low Mn content of the welding rod components, fine cracks were observed in the heat affected zone.
Ｅ−１３は被覆率が低く、ルチール量が上限を超えてい
ることから溶接棒先端の保護筒が十分確保できず、スパ
ッタが多く、溶接棒成分のＳｉ， Ｍｎ量が低いことか
らブローホールの発生が認められた。E-13 has a low coverage rate and the amount of rutile exceeds the upper limit, so it is not possible to secure a sufficient protective tube for the tip of the welding rod, there is a lot of spatter, and the amount of Si and Mn in the welding rod is low, so it is difficult to protect the tip of the welding rod. Occurrence was observed.
Ｅ−１４はｃａＦｚｆｆｉが高すぎて被覆剤のＣａＯ／
ＣａＦｚ比が低く、溶接スラグの軟化点が高くスパッタ
量も多い。又溶接棒成分のＭｎｌｉｌが上限を超えてお
りスラグ剥離性も劣化した。E-14 has too high caFzffi and the coating material CaO/
The CaFz ratio is low, the softening point of welding slag is high, and the amount of spatter is large. Furthermore, Mnlil in the welding rod component exceeded the upper limit, and the slag removability was also deteriorated.
Ｅ−１５は被覆剤の金属フッ化物量が下限を割っている
ことがらＣａｂ／Ｃａｂ．比も高くスパッタ量が多くか
つスラグ流動性も悪く溶接作業性の面で問題があると同
時に、溶接棒成分のＣ，Ｃｒが上限を超えていることか
ら、溶着金属に割れが認められた。E-15 was classified as Cab/Cab. since the amount of metal fluoride in the coating material was below the lower limit. The welding ratio was high, the amount of spatter was large, and the slag fluidity was poor, which caused problems in terms of welding workability.At the same time, cracks were observed in the weld metal because the C and Cr content of the welding rod exceeded the upper limit.
Ｅ−１６は被覆剤の金属フッ化物が上限を超え炭酸塩が
下限を割っていることからＣａＯ／ＣａＦｔの比が低く
ルチールが無添加であることからスラグ流動性が過度に
なりすぎてビード表面に均一にスラグが被包せずスパッ
タ量も多い。又、溶接棒成分のＮｉ゛が上限を超えてい
ることから母材熱影響部に割れが認められた。In E-16, the metal fluoride in the coating material exceeds the upper limit and the carbonate exceeds the lower limit, so the CaO/CaFt ratio is low and rutile is not added, so the slag fluidity becomes excessive and the bead surface The slag is not evenly covered and there is a large amount of spatter. In addition, cracks were observed in the heat-affected zone of the base metal because the Ni content of the welding rod exceeded the upper limit.
Ｅ−１７は被覆剤の炭酸塩が低＜ 、ＣａＯ／ＣａＦｚ
比が下限を割っていることから、スラグ流動性が悪い。E-17 has a coating material with low carbonate content, CaO/CaFz
Since the ratio is below the lower limit, the slag fluidity is poor.
又溶接捧成分のＶ， Ｎｂ， Ｃｕが上限を超えている
ことから、溶着金属に割れが認められた。In addition, cracks were observed in the weld metal because the welding additive components V, Nb, and Cu exceeded the upper limits.
Ｅ−１８は被覆剤の炭酸塩が上限を超えており、スラグ
発生量、スバッタが多く、スラグ流動性が悪いなど溶接
作業性の面で問題があった。In E-18, the carbonate content of the coating material exceeded the upper limit, and there were problems in terms of welding workability, such as a large amount of slag generation and spatter, and poor slag fluidity.
注）
＊１
＊２
＊３
＊４
＊５
＊６
＊７
＊８
＊９
＊１０
ＪＩＳＦＳｉ３
ＪＩＳＦＴｉＬ＋
ＪＩＳＭｎＥ
グラファイト
ＪＩＳＭＣｒ
ＪＩＳＦＭｏＬ
ＪＩＳＦＶ２
ＪＩＳＦＮｂ Ｉ
Ｎｉ粉
Ｃｕ粉
（Ｓｉ−１１．２％）
（Ｔｉ＝４１．９％）
（Ｍｎ＝９９．９％）
（Ｃ ＝９９．９％）
（Ｃｒ ＝ ９９． ９％）
（Ｍｏ＝６１．５％）
（Ｖ ＝５２．３％）
（Ｎｂ＋Ｔａ＝６７．５％）
（Ｎｉ＝９９．９％）
（Ｃｕ＝９９．９％）
〔発明の効果］
以上述べたように本発明によるレールエンクローズアー
ク溶接用被覆アーク溶接棒は、良好な溶接作業性と継手
性能が得られレール溶接の信頼性を大幅に向上しうろこ
とが可能となりその工業的価値は極めて大きい。Note) *1 *2 *3 *4 *5 *6 *7 *8 *9 *10 JISFSi3 JISFTiL+ JISMnE Graphite JISMCr JISFMoL JISFV2 JISFNb I Ni powder Cu powder (Si-11.2%) (Ti=41.9% ) (Mn=99.9%) (C=99.9%) (Cr=99.9%) (Mo=61.5%) (V=52.3%) (Nb+Ta=67.5%) ( Ni = 99.9%) (Cu = 99.9%) [Effects of the invention] As described above, the coated arc welding rod for rail enclosed arc welding according to the present invention provides good welding workability and joint performance. This makes it possible to greatly improve the reliability of rail welding, and its industrial value is extremely large.
第１図はレール鋼の断面図、第２図は溶着金属の炭素量
と架橋率の関係を示した図、第３図は被覆剤のＣａＯ／
ＣａＦｚ比と軟化点の関係を示した図である。
１・・・レール足部、２・・・レール腹部、３・・・レ
ール頭部、４・・・レール頭表面
第１図Figure 1 is a cross-sectional view of rail steel, Figure 2 is a diagram showing the relationship between the carbon content of the weld metal and the crosslinking rate, and Figure 3 is a diagram showing the relationship between the carbon content of the weld metal and the crosslinking rate.
It is a figure showing the relationship between CaFz ratio and softening point. 1...Rail foot, 2...Rail abdomen, 3...Rail head, 4...Rail head surface Figure 1
Claims (2)
２〜５５％、金属フッ化物の１種又は２種以上を１３〜
２３％、ルチール：０．５〜９．５％、被覆剤中のＣａ
Ｏ／ＣａＦ＿２の比が１．２〜１．８の範囲にある被覆
剤が溶接棒全重量に対して１５〜３２％被覆され、かつ
溶接棒全重量％でＣ：０．６５〜１．５％、Ｓｉ：０．
２〜２．２％、Ｍｎ：０．６〜２．５％含有することを
特徴とするレールのエンクローズアーク溶接用被覆アー
ク溶接棒。(1) One or more carbonates are added to the outer periphery of a core wire containing C: 1.0 to 1.5% by weight.
2-55%, 13-55% of one or more metal fluorides
23%, Rutile: 0.5-9.5%, Ca in coating material
The coating material having an O/CaF_2 ratio in the range of 1.2 to 1.8 covers 15 to 32% of the total weight of the welding rod, and the total weight of the welding rod has C: 0.65 to 1.5. %, Si:0.
A coated arc welding rod for enclosed arc welding of rails, characterized by containing 2 to 2.2% of Mn and 0.6 to 2.5% of Mn.
２〜５５％、金属フッ化物の１種又は２種以上を１３〜
２３％、ルチール：０．５〜９．５％、被覆剤中のＣａ
Ｏ／ＣａＦ＿２の比が１．２〜１．８の範囲にある被覆
剤が溶接棒全重量に対して１５〜３２％被覆され、かつ
溶接棒全重量％でＣ：０．６５〜１．５％、Ｓｉ：０．
２〜２．２％、Ｍｎ：０．６〜２．５％、更にＣｒ：１
．３％以下、Ｍｏ：０．３％以下、Ｖ：０．３％以下、
Ｎｂ：０．１％以下、Ｎｉ：２．０％以下、Ｃｕ：０．
３％以下の１種又は２種以上を含有することを特徴とす
るレールのエンクローズアーク溶接用被覆アーク溶接棒
。(2) One or more carbonates are added to the outer periphery of the core wire containing C: 1.0 to 1.5% by weight.
2-55%, 13-55% of one or more metal fluorides
23%, Rutile: 0.5-9.5%, Ca in coating material
The coating material having an O/CaF_2 ratio in the range of 1.2 to 1.8 covers 15 to 32% of the total weight of the welding rod, and the total weight of the welding rod has C: 0.65 to 1.5. %, Si:0.
2-2.2%, Mn: 0.6-2.5%, further Cr: 1
．． 3% or less, Mo: 0.3% or less, V: 0.3% or less,
Nb: 0.1% or less, Ni: 2.0% or less, Cu: 0.
A coated arc welding rod for enclosed arc welding of rails, characterized in that it contains 3% or less of one or more kinds.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5065089A JP2687008B2 (en) | 1989-03-02 | 1989-03-02 | Coated arc welding rod for enclosed arc welding of rails |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5065089A JP2687008B2 (en) | 1989-03-02 | 1989-03-02 | Coated arc welding rod for enclosed arc welding of rails |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02229693A true JPH02229693A (en) | 1990-09-12 |
| JP2687008B2 JP2687008B2 (en) | 1997-12-08 |
Family
ID=12864816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5065089A Expired - Lifetime JP2687008B2 (en) | 1989-03-02 | 1989-03-02 | Coated arc welding rod for enclosed arc welding of rails |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2687008B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05169292A (en) * | 1991-12-18 | 1993-07-09 | Nippon Steel Corp | Rail repairing welding method |
-
1989
- 1989-03-02 JP JP5065089A patent/JP2687008B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05169292A (en) * | 1991-12-18 | 1993-07-09 | Nippon Steel Corp | Rail repairing welding method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2687008B2 (en) | 1997-12-08 |
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