JPH02107744A - Ferritic stainless steel excellent in weldability and corrosion resistance - Google Patents
Ferritic stainless steel excellent in weldability and corrosion resistanceInfo
- Publication number
- JPH02107744A JPH02107744A JP26067388A JP26067388A JPH02107744A JP H02107744 A JPH02107744 A JP H02107744A JP 26067388 A JP26067388 A JP 26067388A JP 26067388 A JP26067388 A JP 26067388A JP H02107744 A JPH02107744 A JP H02107744A
- Authority
- JP
- Japan
- Prior art keywords
- corrosion resistance
- steel
- ferritic stainless
- stainless steel
- weldability
- 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
- 238000005260 corrosion Methods 0.000 title claims abstract description 41
- 230000007797 corrosion Effects 0.000 title claims abstract description 41
- 229910001220 stainless steel Inorganic materials 0.000 title claims abstract description 11
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 12
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 11
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 8
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 4
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 3
- 239000012535 impurity Substances 0.000 claims abstract description 3
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 3
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910000831 Steel Inorganic materials 0.000 abstract description 12
- 239000010959 steel Substances 0.000 abstract description 12
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 6
- 239000010953 base metal Substances 0.000 abstract description 3
- 230000002542 deteriorative effect Effects 0.000 abstract description 3
- 239000000203 mixture Substances 0.000 abstract description 3
- 230000001105 regulatory effect Effects 0.000 abstract 2
- 229910052750 molybdenum Inorganic materials 0.000 abstract 1
- 238000003466 welding Methods 0.000 description 17
- 230000000694 effects Effects 0.000 description 10
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- 238000005554 pickling Methods 0.000 description 5
- 239000011324 bead Substances 0.000 description 4
- 238000000137 annealing Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005097 cold rolling Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 208000014451 palmoplantar keratoderma and congenital alopecia 2 Diseases 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 239000002436 steel type Substances 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- -1 chlorine ions Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Landscapes
- Arc Welding In General (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、化学工業を始めとした揮々の分野に広く利用
可能な、溶接性と耐食性に優れたフェライト系ステンレ
ス鋼に関するものである。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a ferritic stainless steel with excellent weldability and corrosion resistance, which can be widely used in various fields including the chemical industry.
〈従来の技術〉
フェライト系ステンレス鋼は、オーステナイト系ステン
レス鋼と比較すると耐応力腐食割れに著しく優れている
が、一般的に耐食性と溶接性ならびに溶接部の特性や機
械的性質が劣っている。しかしながら、製廿技術の進歩
により、極低Ｃ，Ｈのフェライト系ステンレス鋼の製造
が可能となり、さらに、Ｔｉ、 Ｎｂ、 Ｖなどの元
素を添加して溶接部の耐食性や機械的性質が改善された
鋼種が開発されている。例えば、これらの鋼種は特公昭
５５２１１０２号公報に開示されているが、耐食性、成
形性、溶接性に優れており、ボイラー管体や温水器など
のような溶接が施される構造物に適用されるに至ってい
る。<Prior Art> Ferritic stainless steels have significantly better stress corrosion cracking resistance than austenitic stainless steels, but are generally inferior in corrosion resistance, weldability, and properties and mechanical properties of welded parts. However, advances in manufacturing technology have made it possible to manufacture ferritic stainless steel with extremely low C and H, and the corrosion resistance and mechanical properties of welded parts have been improved by adding elements such as Ti, Nb, and V. Steel grades have been developed. For example, these steel types are disclosed in Japanese Patent Publication No. 5521102, and they have excellent corrosion resistance, formability, and weldability, and are applicable to welded structures such as boiler tubes and water heaters. It has reached the point where
しかしながら、上記鋼ｆｌＩ＋を用いても、例えばＴ１
Ｇ溶接施工時に十分に溶接雲囲気をコントロールしない
と溶接部にテンパーカラーが生じ、実使用時にこの部分
で著しく腐食が生じ、場合によっては短期間で穴あきが
生じている。この（川向は、使用される構造物が複雑化
、多様化するにしたがって著しくなる傾向にあり、また
、生成したテンパーカラーを施工後、電屑、研摩あるい
は酸洗により除去することも困難となっている。However, even if the steel flI+ is used, for example, T1
If the welding cloud is not sufficiently controlled during G-welding, temper color will occur in the welded area, and during actual use, this area will become severely corroded, and in some cases, holes will occur in a short period of time. This problem tends to become more pronounced as the structures used become more complex and diversified, and it is also difficult to remove the generated temper color after construction by using electrical scraps, polishing, or pickling. ing.
そこで、従来の５ＵＳ４４４タイプより溶接部の耐食性
が優れた鋼種の開発が強く望まれている。Therefore, there is a strong desire to develop a steel type that has better corrosion resistance at welded parts than the conventional 5US444 type.
〈発明が解決しようとする課題〉
本発明の目的は、素材の元来有している溶接性や機械的
性質を１１なうことなく、溶接部耐食性を著しく改善し
たフェライト系ステンレス鋼を提供することである。<Problems to be Solved by the Invention> An object of the present invention is to provide a ferritic stainless steel that has significantly improved corrosion resistance in welded areas without impairing the weldability or mechanical properties originally possessed by the material. That's true.
〈課題を解決するための手段〉
このような現状に臨み、木発明者らは鋭意努力した結果
、Ｓｉを１．０〜２．０％含有さ一已、さらにＭｎ量を
０．５％以下とすることにより、素材の溶接性や機械的
性質を低下させることなく、母材耐食性や溶接部耐食性
が著しく改善されることを見出した。<Means for solving the problem> Faced with this current situation, the inventors of wood made earnest efforts to reduce the Si content to 1.0 to 2.0% and further reduce the Mn content to 0.5% or less. It has been found that by doing so, the base metal corrosion resistance and the weld zone corrosion resistance can be significantly improved without deteriorating the weldability or mechanical properties of the material.
即ら、本発明は、重用？イで、Ｃ：Ｏ，０１％以下及び
Ｎ：０．０１％以下で、かつＣ−ｌ−Ｎ ： ０．０
１５％以下Ｓｉ ： １．Ｏ〜２．０％、 Ｍｎ：
０．５％以下、ｒ’：ｏ、ｏ４％以−Ｆ、 Ｓ ：
０．００１〜０．００７％、 Ｃｒ ： １５〜２５％
、 Ｍ。In other words, is the present invention important? A, C: O, 01% or less, N: 0.01% or less, and C-l-N: 0.0
15% or less Si: 1. O~2.0%, Mn:
0.5% or less, r': o, o4% or more - F, S:
0.001~0.007%, Cr: 15~25%
, M.
：１，０〜３．０％、Δｔ ： ０．００５〜０．１
％を含有し、Ｎｂ：Ｏ，＋Ｓ〜０．５％及びＴｉ ：
０．１５〜０．５％の１種あるいは２種を含有し、かつ
Ｎｂ十Ｔｉ ： ０．１５〜０．５％ならびにＮｌ＋−
トＴｉ ： （Ｃ４−Ｎ）ｘｏ以上で、残部はＦｅ及
び不可避的不純物からなることを特徴とする溶接性と耐
食性に優れたフェライト系ステンレス鋼であり、あるい
は必要に応してこれにさらにＣｕＯ１０５〜０．２％含
有させたものである。:1.0~3.0%, Δt: 0.005~0.1
%, Nb:O, +S~0.5% and Ti:
Contains 0.15 to 0.5% of one or two types, and Nb+Ti: 0.15 to 0.5% and Nl+-
Ti: A ferritic stainless steel with excellent weldability and corrosion resistance characterized by having at least (C4-N)xo and the remainder consisting of Fe and unavoidable impurities, or if necessary, further containing CuO105. It contains ~0.2%.
く作 用〉
以下に本発明の組成側合の限定理由を具体的に説明する
。Function> The reasons for limiting the compositional combinations of the present invention will be specifically explained below.
Ｃ； Ｃは周知の如＜Ｃｒと結合してＣｒ炭化物を形成
しやすく、とりわけ溶接時の熱影響部に形成され、粒界
腐食を生じさ仕る。また成形性にも悪影響を及ぼすので
、その上限は０．０１重量％（以下％で示す）とした。C: As is well known, C easily combines with Cr to form Cr carbide, which is particularly formed in the heat-affected zone during welding and causes intergranular corrosion. Since it also has a negative effect on moldability, the upper limit is set at 0.01% by weight (hereinafter expressed as %).
また、Ｃは少なければ少ないほどこれら性質にとっては
良いので特に下限は設けない。Further, since the smaller the amount of C, the better for these properties, there is no particular lower limit set.
Ｓｉ； Ｓｉは本発明を特徴づける重要な元素である
。第１図に、実験室的に溶製した小型鋼塊ｆオを用いて
公知の条件で熱延、焼鈍、冷延、仕上焼鈍して、仮１！
Ｖ ｌ 、 Ｏｍｍの仕上焼鈍板を作製し、溶接電圧１
０Ｖ、溶接電流８０〜９０Ａ、溶接速度４５０〜６００
ｍ＋ｎ ／ ｍｍの条件下で１，６柵φのタングステン
電極を用いて、１・−チ側は８ Ｒ／ ５ｌｎＡｒガス
、裏ビード側はｌ ｌ ／ ａｍ、 Ａｒ＋ １％Ｏｔ
ガス及びへｒ＋１０％ｏｚガスでシールを行いながら′
Ｉ″ＩＣ溶接（なめ付は溶接）し、裏ビード側が試験面
となるようにしたＣＡＳＳ試験（Ｊ Ｉ ５−Ｄ−２０
１） １６時間後の発錆の程度に及ぼす５ｔｆｆｉの影
響を示す。Si: Si is an important element that characterizes the present invention. Figure 1 shows that a small steel ingot made in the laboratory was hot rolled, annealed, cold rolled, and finish annealed under known conditions.
A finish annealed plate with V l of Omm was prepared, and the welding voltage was 1.
0V, welding current 80-90A, welding speed 450-600
Using a tungsten electrode with a diameter of 1.6 mm under the condition of m+n/mm, 8 R/5lnAr gas on the 1st side and l/am, Ar+ 1%Ot on the back bead side.
While sealing with gas and +10% oz gas'
CASS test (J I 5-D-20
1) The influence of 5tffi on the degree of rusting after 16 hours is shown.
発錆の程度（溶接部）は次のように評価した。The degree of rust (welded area) was evaluated as follows.
Ａ：はとんど発錆なし
Ｂ：発錆程度小
Ｃ：発錆程度中
Ｄ：著しく発錆
Ｓｉ量が１．０％以上となると著しく耐食性が良好とな
ることがわかる。しかしながら、Ｓｉ量が２．０％を超
えると溶接部の成形性や靭性、母材の引張特性が低下す
るので、Ｓｉは１０〜２．０％に限定される。A: Hardly any rust B: Low rust C: Medium rust D: Significant rust It can be seen that when the amount of Si is 1.0% or more, the corrosion resistance is significantly improved. However, if the Si amount exceeds 2.0%, the formability and toughness of the welded part and the tensile properties of the base material will deteriorate, so the Si content is limited to 10 to 2.0%.
Ｍｎ； Ｍｎも本発明の中で重要な元素である。即ち
、Ｍｎ１ｉが０．５％を超えると前述したようにＳｉｌ
を１．０％以上加えても、はとんど溶接部耐食性の改善
効果は認められないからである。したがってその上限は
０．５％とした。また、その量は低くても何ら不都合は
生じないので特に下限は設けない。Mn; Mn is also an important element in the present invention. That is, when Mn1i exceeds 0.5%, Sil
This is because even if 1.0% or more is added, no improvement effect on the corrosion resistance of the weld zone is observed. Therefore, the upper limit was set at 0.5%. Further, since no problem will occur even if the amount is low, there is no particular lower limit set.
Ｐ、 Ｐは耐食性を始めとして、靭性、成形性などに
悪影響を及ぼす元素であり、とりわけ０．０４％を超え
ると顕著となることから、上限は０．０４％とした。ま
た、その性質上、少なければ少ない方が好都合であるの
で、特に下限は設けない。P and P are elements that have an adverse effect on corrosion resistance, toughness, formability, etc., and this becomes especially noticeable when the content exceeds 0.04%, so the upper limit was set at 0.04%. Moreover, since the smaller the number, the more convenient it is due to its nature, there is no particular lower limit set.
Ｓ； Ｓは耐食性とりわけ耐孔食性に有害な元素であり
、０．００７％を超えると顕著となるため上限は０．０
０７％とした。しかしながら、低ずぎると溶接時の湯流
れ性を低下させるので、その下限は０．００１％に限定
される。S; S is an element harmful to corrosion resistance, especially pitting corrosion resistance, and becomes noticeable when it exceeds 0.007%, so the upper limit is 0.0
It was set at 07%. However, if it is too low, the flowability during welding will be reduced, so the lower limit is limited to 0.001%.
Ｃｒ； Ｃｒは耐食性に非常に有効な元素であり、通
常はその含有量に比例して効果を有するが、十分な耐食
性を得るには１５％は必要であり、下限は１５％とした
。しかしながら、その含有量が多くなりすぎると、σ相
などの脆い金属間化合物が生成し靭性、延性が低下する
などの＋＋ｈ題が生じ易くなり、特に２５％を超えると
それが顕著となるのでその上限は２５％とした。Cr; Cr is a very effective element for corrosion resistance, and usually has an effect in proportion to its content, but 15% is necessary to obtain sufficient corrosion resistance, and the lower limit was set at 15%. However, if the content becomes too large, brittle intermetallic compounds such as σ phase are formed, which tends to cause problems such as a decrease in toughness and ductility. The upper limit was set at 25%.
Ｍｏ； Ｍｏも同様に耐食性に非常に有効な元素であ
る。しかも塩素イオン存在下の環境においては特に優れ
た性質を有しており、その特性を十分に得るには最低１
．０％は必要なので、下限を１．０％とした。一方、同
時に多層に含有させると著しく素材を脆化させ、３゜０
％を超えると顕著となることから上限は３．０％とした
。Mo; Mo is also an element that is very effective for corrosion resistance. Moreover, it has particularly excellent properties in an environment where chlorine ions are present, and to fully obtain its properties, at least
．． Since 0% is necessary, the lower limit was set to 1.0%. On the other hand, if it is contained in multiple layers at the same time, it will significantly embrittle the material and 3°0
%, the upper limit was set at 3.0%.
Ａｌ； 八ｌは通常脱酸剤としてよく用いられており
、その作用を得るには最低ｏ、ｏｏｓ％程度は必要であ
り、下限を０．００５％とした。一方、多量に添加する
と生じる介在物が８１状あるいは１１１人なものとなり
、成形性や耐食性を劣化させるので上限は０．１％とし
た。Al; 8L is commonly used as a deoxidizing agent, and in order to obtain its effect, a minimum amount of about o, oos% is required, and the lower limit was set at 0.005%. On the other hand, if a large amount is added, inclusions will be formed in the shape of 81 or 111, deteriorating formability and corrosion resistance, so the upper limit was set at 0.1%.
Ｎ； ＮはＣと同様に素材の成形性を始めとした機械的
性質に悪影響を及ぼすばかりか、溶接時の熱影響部にＣ
「窒化物を生成させ易く、その結果粒界腐食が生じるの
で、その上限は０，０１％とした。N: Like C, N not only has a negative effect on the mechanical properties including the formability of the material, but also causes C to form in the heat-affected zone during welding.
"Nitrides are likely to form, resulting in intergranular corrosion, so the upper limit was set at 0.01%.
Ｎｂ、 Ｔｉ ； Ｎｂ、 ＴｉはＣ「よりも炭窒化
物形成能が強い、従って溶接時の熱影響部でのＣｒ炭窒
化物生成を抑制し、優れた耐粒界腐食性を得るには、そ
の化学当量的な関係から最低（Ｃ＋Ｈ）ｘＯ以上のＮｂ
、 Ｔｉが必要であり、また製鋼時の酸化物生成等を考
慮すると０．１５％以上となる。従って下限は０．１５
％とした。また、その添加量が多くなると耐食性とりわ
け耐孔食性が低下し、０．５％を超えると顕著となるこ
とより、その上限は０．５％とした。Nb, Ti; Nb, Ti has a stronger carbonitride forming ability than C. Therefore, in order to suppress the formation of Cr carbonitride in the heat affected zone during welding and obtain excellent intergranular corrosion resistance, Due to its chemical equivalence relationship, Nb of at least (C+H)xO
, Ti is required, and the amount is 0.15% or more, taking into account the formation of oxides during steel manufacturing. Therefore, the lower limit is 0.15
%. Further, as the amount added increases, corrosion resistance, especially pitting corrosion resistance, decreases, which becomes noticeable when it exceeds 0.5%, so the upper limit was set at 0.5%.
また、Ｎｂ、 Ｔｉについては単独添加でも複合添加で
も本発明は達せられるので、１種又は２種添加とする。Furthermore, since the present invention can be achieved by adding Nb and Ti either singly or in combination, they may be added singly or in combination.
Ｃ，Ｎ、Ｃ，Ｎは前述した如く、溶接時の熱影響部での
Ｃｒ炭窒化物の粒界析出による粒界腐食に対して有害で
あり、この防止策としてＴｉ、 Ｎｂが添加される。し
かしながら、Ｃ＋Ｈが１５０ｐを超えると上述したよう
にＴｉ、 Ｎｂを添加してもその効果が少ないので、Ｃ
＋Ｈの上限は０．０１５％さした。As mentioned above, C, N, C, and N are harmful to intergranular corrosion due to intergranular precipitation of Cr carbonitride in the heat affected zone during welding, and Ti and Nb are added to prevent this. . However, as mentioned above, when C+H exceeds 150p, the effect of adding Ti and Nb is small;
The upper limit of +H was set at 0.015%.
Ｃｕ； Ｃｕはステンレス鋼の耐誘性改善に有効な元
素であり、また溶接部の耐食性改善にも有効な元素であ
るので必要に応じて添加できる。しかし、その効果を得
るには最低０．０５％が必要であり、下限は０．０５％
とした。添加量が０．２％を超える溶接時に溶接部でＣ
ｕが粒界に偏析しやすくなり、脆化を招くので上限は０
．２％とした。Cu: Cu is an element effective in improving the induction resistance of stainless steel, and is also effective in improving the corrosion resistance of welded parts, so it can be added as necessary. However, to obtain this effect, a minimum concentration of 0.05% is required, and the lower limit is 0.05%.
And so. When welding with an additive amount exceeding 0.2%, C
The upper limit is 0 because u tends to segregate at grain boundaries and cause embrittlement.
．． It was set at 2%.
本発明の組成の鋼の溶製は、転炉や電気炉、あるいはさ
らに真空脱ガス炉での精練が可能である。The steel having the composition of the present invention can be smelted in a converter, an electric furnace, or further in a vacuum degassing furnace.
このようにして溶製された鋼は、造塊−分解圧延、ある
いは連続鋳造によりスラブにされ、引続き熱間圧延、熱
延板焼鈍、酸洗、冷間圧延、仕上焼鈍、酸洗等の通常の
一連の工程を経て、製品仮になる。The steel produced in this way is made into a slab by ingot-decomposition rolling or continuous casting, and then subjected to conventional processes such as hot rolling, hot-rolled plate annealing, pickling, cold rolling, finish annealing, and pickling. After going through a series of steps, the product becomes a tentative product.
〈実施例〉
以下に実施例に基づいて本発明を説明するが、本発明は
これに限られるものではない。<Examples> The present invention will be described below based on Examples, but the present invention is not limited thereto.
表１に示す化学成分の５０ｋｇ小型鋼塊を実験室的に溶
製し、公知の条件で熱間圧延、熱延板焼鈍。A 50 kg small steel ingot having the chemical composition shown in Table 1 was melted in a laboratory, hot rolled under known conditions, and hot rolled sheet annealed.
酸洗、冷間圧延、仕上焼鈍、酸洗を行って板厚１．０胴
の仕上焼鈍板を作製し、以下の項目について調査した。Pickling, cold rolling, finish annealing, and pickling were performed to produce a finish annealed plate with a plate thickness of 1.0 mm, and the following items were investigated.
母材の耐食性は孔食発生電位をＪＩＳ−Ｇ−０５７７に
より、成形性についてはエリクセン試験をＪＩＳ−Ｚ−
２２４７により求めた。The corrosion resistance of the base material is determined by the pitting corrosion potential according to JIS-G-0577, and the formability is determined by the Erichsen test by JIS-Z-
2247.
また溶接部の耐食性はＣＡＳＳ試験を、ＪＩＳ−Ｄ−２
０１に従い、裏ビード側を試験面となるように行い、成
形性についてはエリクセン試験をＪＩＳ −Ｚ−２２４
７に従い、溶接部の表面を０３２０番研摩後に、ビード
部が中心となるように張り出し、靭性についてはシャル
ピー１１１％Ｍ試験をＪＩＳ−Ｚ２２４２に従い、溶接
ままで溶接部にＶノツチを入れて試験した。In addition, the corrosion resistance of welded parts is determined by CASS test, JIS-D-2
01, with the back bead side as the test surface, and for moldability, the Erichsen test was performed according to JIS-Z-224.
7, after polishing the surface of the welded part with No. 0320, it was stretched out so that the bead part was in the center, and the toughness was tested by making a V-notch in the welded part while still welding according to JIS-Z2242 using Charpy 111% M test. .
なお、溶接部の特性を評価するに当たり、次のような条
件でＴＩＧ？８接（ナメ付は溶接）を行っ溶接電圧
溶接電流
溶接速度
電 極
シールガス
０Ｖ
８０〜９０Δ
４５０〜６００ｍｍ ／ ｍａｎ
ｌ、６ｍｍφタングステン電極
表ビード側 ＾ｒ ８ｆｆｉ／Ｉｌｎ臭ヒ゛−ド側
八ｒ＋１％０゜
１１ ／ ｓｉｎ
なお各試験の評価は次のように行った。In addition, when evaluating the characteristics of the welded part, TIG? Perform 8 welding (welding with tongue) Welding voltage Welding current Welding speed Electrode Seal gas 0V 80~90Δ 450~600mm/man l, 6mmφ tungsten electrode surface bead side ^r 8ffi/Iln odor side
8r+1%0°11/sin The evaluation of each test was performed as follows.
孔食発生電位： Ｖ’ｃ＋ｏｏｐｈ （ｖｓ Ａ６／八
ｇへ７）で評価母材の成形性：エリクセン値（胴）
溶接部耐食性：１６時間ＣΔＳＳ試験後の発錆程度を下
記の如く評価
Ａ：はとんど発錆なし
Ｂ：発錆程度小
Ｃ：発錆程度中
Ｄ：著しく発錆
溶接部成形性：エリクセン値（ｎ＋ｍ））４接部靭性
＝破面観察による延性−脆性温度（°Ｃ）
表
表２より明らかな如く、溶接部の耐食性にはＳｉ添加の
効果が著しく、１．０％以上で大であり、またＭｎを低
下させることも必要であることがわかる。Potential for pitting corrosion: Evaluated by V'c + ooph (vs A6/8g to 7) Formability of base material: Erichsen value (shell) Corrosion resistance of welded part: The degree of rusting after 16 hours CΔSS test was evaluated as follows A: Almost no rust B: Slight rust C: Medium rust D: Significant rust Formability of weld: Erichsen value (n+m)) 4 Joint toughness
=Ductility-brittle temperature (°C) by fracture surface observation As is clear from Table 2, the effect of Si addition on the corrosion resistance of welds is significant, and is large at 1.0% or more, and it also reduces Mn. It turns out that it is also necessary.
しかしながら（Ｃ＋Ｎ）ｆｆｉが０．０１５％を超えた
り、ＴｉあるいはＮｂまたは（Ｔｉ十Ｎｂ） Ｍが本発
明成分より少ないと、たとえｓ＋５１が１．０〜２．０
％の範囲であっても十分な溶接部耐食性が得られず、ま
た成形性や靭性が劣ることもわかる。一方、Ｓｉ計が２
．０％を超えると、溶接部成形性、靭性が低下すること
もわかる。また、Ｃ＋Ｊｌが０．０５〜０．２％の範囲
のものについては、溶接部耐食性は改善されていること
がわかるが、０，２％を越えると明らかに溶接部靭性、
成形性が低下することも明らかである。However, if (C+N)ffi exceeds 0.015%, or if Ti, Nb, or (Ti + Nb) M is less than the present invention components, even if s+51 is 1.0 to 2.0
% range, sufficient corrosion resistance of the weld zone cannot be obtained, and formability and toughness are also inferior. On the other hand, the Si total is 2
．． It can also be seen that when the content exceeds 0%, the formability and toughness of the welded part deteriorate. In addition, it can be seen that the weld corrosion resistance is improved when C+Jl is in the range of 0.05 to 0.2%, but when it exceeds 0.2%, the weld toughness clearly deteriorates.
It is also clear that the moldability is reduced.
〈発明の効果〉
以上示したように、本発明鋼は母材、溶接部を含めた成
形加工性や靭性に優れており、とりわけ溶接部耐食性が
著しく改善されていることに特徴がある。したがって、
温水機やボイラー缶体を始めとした溶接構造用鋼として
十分な機能を備えた素材である。<Effects of the Invention> As shown above, the steel of the present invention is characterized by excellent formability and toughness including the base metal and the welded part, and in particular, the corrosion resistance of the welded part is significantly improved. therefore,
It is a material with sufficient functionality as steel for welded structures such as water heaters and boiler bodies.
４、4,
第１図はＴＩＧ溶接部耐食性に及ぼすＳｉ量の影響を示
す図である。FIG. 1 is a diagram showing the influence of the amount of Si on the corrosion resistance of TIG welds.
Claims (1)
以下で、かつＣ＋Ｎ：０．０１５％以下、Ｓｉ：１．０
〜２．０％、Ｍｎ：０．５％以下、Ｐ：０．０４％以下
、Ｓ：０．００１〜０．００７％、Ｃｒ：１５〜２５％
、Ｍｏ：１．０〜３．０％、Ａｌ：０．００５〜０．１
％を含有し、Ｎｂ：０．１５〜０．５％及びＴｉ：０．
１５〜０．５％の１種あるいは２種を含有し、かつＮｂ
＋Ｔｉ：０．１５〜０．５％ならびにＮｂ＋Ｔｉ：（Ｃ
＋Ｎ）×８以上で、残部はＦｅ及び不可避的不純物から
なることを特徴とする溶接性と耐食性に優れたフェライ
ト系ステンレス鋼。 ２、請求項１記載の成分に重量％で、Ｃｕ：０．０５〜
０．２％を加えたことを特徴とする溶接性と耐食性に優
れたフェライト系ステンレス鋼。[Claims] 1. In weight%, C: 0.01% or less and N: 0.01%
and C+N: 0.015% or less, Si: 1.0
~2.0%, Mn: 0.5% or less, P: 0.04% or less, S: 0.001-0.007%, Cr: 15-25%
, Mo: 1.0-3.0%, Al: 0.005-0.1
%, Nb: 0.15-0.5% and Ti: 0.
Contains 15 to 0.5% of one or two types, and Nb
+Ti: 0.15-0.5% and Nb+Ti: (C
A ferritic stainless steel with excellent weldability and corrosion resistance, characterized by having a diameter of +N)×8 or more, with the remainder consisting of Fe and unavoidable impurities. 2. Cu: 0.05 to 0.05% by weight in the component according to claim 1
Ferritic stainless steel with excellent weldability and corrosion resistance, characterized by the addition of 0.2%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63260673A JPH0762218B2 (en) | 1988-10-18 | 1988-10-18 | Ferritic stainless steel with excellent weldability and corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63260673A JPH0762218B2 (en) | 1988-10-18 | 1988-10-18 | Ferritic stainless steel with excellent weldability and corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02107744A true JPH02107744A (en) | 1990-04-19 |
| JPH0762218B2 JPH0762218B2 (en) | 1995-07-05 |
Family
ID=17351182
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63260673A Expired - Fee Related JPH0762218B2 (en) | 1988-10-18 | 1988-10-18 | Ferritic stainless steel with excellent weldability and corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0762218B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006241564A (en) * | 2005-03-07 | 2006-09-14 | Nisshin Steel Co Ltd | Ferritic stainless steel for welded structure |
| JP2006263811A (en) * | 2005-02-28 | 2006-10-05 | Jfe Steel Kk | Ferritic stainless steel filler metal rod for tig welding |
| JP2010229470A (en) * | 2009-03-26 | 2010-10-14 | Nisshin Steel Co Ltd | Welded structure made from stainless steel having superior toughness at weld, and stainless steel sheet to be welded |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5231919A (en) * | 1976-09-20 | 1977-03-10 | Kawasaki Steel Corp | Low carbon ferrite system c -stainless -stainless steel,having rust re sistance and supeior forming property |
| JPS57134542A (en) * | 1981-02-13 | 1982-08-19 | Sumitomo Metal Ind Ltd | Ferrite stainless steel with superior corrosion resistance |
| JPS57156893A (en) * | 1981-03-23 | 1982-09-28 | Daido Steel Co Ltd | Welding material |
| JPS5871356A (en) * | 1981-10-23 | 1983-04-28 | Nippon Steel Corp | Ferritic stainless steel with superior service performance, mainly corrosion resistance and its manufacture |
| JPS5983749A (en) * | 1982-11-02 | 1984-05-15 | Nisshin Steel Co Ltd | Ferrite stainless steel having wheatherability |
-
1988
- 1988-10-18 JP JP63260673A patent/JPH0762218B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5231919A (en) * | 1976-09-20 | 1977-03-10 | Kawasaki Steel Corp | Low carbon ferrite system c -stainless -stainless steel,having rust re sistance and supeior forming property |
| JPS57134542A (en) * | 1981-02-13 | 1982-08-19 | Sumitomo Metal Ind Ltd | Ferrite stainless steel with superior corrosion resistance |
| JPS57156893A (en) * | 1981-03-23 | 1982-09-28 | Daido Steel Co Ltd | Welding material |
| JPS5871356A (en) * | 1981-10-23 | 1983-04-28 | Nippon Steel Corp | Ferritic stainless steel with superior service performance, mainly corrosion resistance and its manufacture |
| JPS5983749A (en) * | 1982-11-02 | 1984-05-15 | Nisshin Steel Co Ltd | Ferrite stainless steel having wheatherability |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006263811A (en) * | 2005-02-28 | 2006-10-05 | Jfe Steel Kk | Ferritic stainless steel filler metal rod for tig welding |
| JP2006241564A (en) * | 2005-03-07 | 2006-09-14 | Nisshin Steel Co Ltd | Ferritic stainless steel for welded structure |
| JP2010229470A (en) * | 2009-03-26 | 2010-10-14 | Nisshin Steel Co Ltd | Welded structure made from stainless steel having superior toughness at weld, and stainless steel sheet to be welded |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0762218B2 (en) | 1995-07-05 |
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