JPS623222B2 - - Google Patents
Info
- Publication number
- JPS623222B2 JPS623222B2 JP17243580A JP17243580A JPS623222B2 JP S623222 B2 JPS623222 B2 JP S623222B2 JP 17243580 A JP17243580 A JP 17243580A JP 17243580 A JP17243580 A JP 17243580A JP S623222 B2 JPS623222 B2 JP S623222B2
- Authority
- JP
- Japan
- Prior art keywords
- concrete
- salt
- steel
- present
- reinforcing bars
- 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.)
- Expired
Links
- 230000003014 reinforcing effect Effects 0.000 claims description 25
- 150000003839 salts Chemical class 0.000 claims description 23
- 230000007797 corrosion Effects 0.000 claims description 20
- 238000005260 corrosion Methods 0.000 claims description 20
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 239000012535 impurity Substances 0.000 claims description 5
- 229910052748 manganese Inorganic materials 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- 229910052720 vanadium Inorganic materials 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims 2
- 229910000831 Steel Inorganic materials 0.000 description 19
- 239000010959 steel Substances 0.000 description 19
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 14
- 239000011780 sodium chloride Substances 0.000 description 7
- 239000007864 aqueous solution Substances 0.000 description 5
- 239000011572 manganese Substances 0.000 description 5
- 150000004763 sulfides Chemical class 0.000 description 5
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003949 liquefied natural gas Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000004576 sand Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 2
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 229910001327 Rimmed steel Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 230000003203 everyday effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000015784 hyperosmotic salinity response Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229940057995 liquid paraffin Drugs 0.000 description 1
- -1 manganese sulfide Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 238000004881 precipitation hardening Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Reinforcement Elements For Buildings (AREA)
- Heat Treatment Of Steel (AREA)
Description
【発明の詳細な説明】
本発明は液化天然ガスの貯蔵用などに使用する
コンクリート用鉄筋の耐食性向上を狙いとしたも
のである。特に最近、砂中に混在する塩分による
鉄筋の局部腐食がクローズアツプされるにともな
い、海浜地帯等に建造される液化天然ガス貯蔵用
コンクリート鉄筋として、極低温における靭性と
同時にこの塩分による局部腐食の軽減が必要不可
欠になつている。DETAILED DESCRIPTION OF THE INVENTION The present invention aims at improving the corrosion resistance of concrete reinforcing bars used for storage of liquefied natural gas. In particular, as local corrosion of reinforcing bars due to salt mixed in sand has been brought to a close attention, concrete reinforcing bars for liquefied natural gas storage built in coastal areas are required to have toughness at extremely low temperatures as well as to prevent local corrosion caused by salt. Mitigation has become essential.
一般にコンクリートは打設時のPH値が約12.5
で、大気に曝らされてる場合の建築、土木用コン
クリートで使用基準に合格しているもののコンク
リートのPHは約12前後であるということが一般的
である。 In general, concrete has a pH value of approximately 12.5 at the time of pouring.
Generally, the pH of concrete for construction and civil engineering applications that is exposed to the atmosphere is around 12, even though it passes the usage standards.
このような高PH値では塩分が存在しない場合に
はコンクリート中の鉄筋表面はγFe2O3からなる
不動態被膜でおおわれ腐食が進行しない。しかし
このようにPH値が高くても鉄筋周辺のコンクリー
ト中に塩分が存在すると、塩分によつて不動態被
膜の一部が破壊され、その部分で鉄の腐食が著し
く進行し、局部腐食を誘発する。 At such a high pH value, in the absence of salt, the reinforcing steel surface in concrete is covered with a passive film consisting of γFe 2 O 3 and corrosion does not progress. However, even if the pH value is high, if salt is present in the concrete around the reinforcing bars, the salt will destroy a part of the passive film, and corrosion of the steel will progress significantly in that area, causing local corrosion. do.
従つて従来腐食が殆んど問題にされていなかつ
たコンクリート用鉄筋も、塩分を含む砂をコンク
リート原料として使用するにつれて、最近急速に
塩分によるコンクリート鉄筋の局部腐食の問題が
クローズアツプされてきた。特に海浜地帯に建造
する例の多い液化天然ガス貯蔵用コンクリートに
は−160℃という極低温での靭性を保証するため
に３％Ni鋼以上の低温用鋼を使用するのが望ま
しいが、この場合でも上記の問題を避けて通るこ
とができない。 Therefore, with the use of salt-containing sand as a raw material for concrete, the problem of local corrosion of concrete reinforcing bars due to salt has rapidly come to the fore, even though corrosion has not been a problem in the past. In particular, it is desirable to use low-temperature steel of 3% Ni steel or higher for concrete for storing liquefied natural gas, which is often constructed in coastal areas, in order to guarantee toughness at extremely low temperatures of -160°C. However, the above problems cannot be avoided.
本発明はこれらの社会事情に応じコンクリート
用鉄筋の耐塩性を著るしく向上させ、しかも極低
温での靭性を保証することを目的としたものでそ
の特徴は鉄筋自身の低温での靭性を向上させると
同時に耐食性をもたせ、とくに孔食、局部腐食を
軽減させることにより、上記の問題点を本質的に
改善したものである。 In response to these social circumstances, the present invention aims to significantly improve the salt resistance of concrete reinforcing bars and guarantee their toughness at extremely low temperatures. At the same time, the above-mentioned problems have been essentially improved by providing corrosion resistance and, in particular, reducing pitting corrosion and local corrosion.
さらに必要に応じて亜鉛メツキ被覆をして使用
するもので、前述したコンクリート中の高PH領域
で塩分が存在する腐食環境中において優れた耐食
性をもち、且つ極低温での靭性に優れた鉄筋に関
するもので、Ｃ：0.05〜1.0％、Si：0.055〜0.20
％、Mn：0.20〜1.2％、Ｐ：0.005〜0.025％、
Ｓ：0.0005〜0.003％、Al：0.001〜0.08％ならび
にCa：0.0002〜0.0005％未満を含有し、さらにNi
を３〜5.5％を含有し、残部鉄および不可避的不
純物からなりPH12前後のコンクリート巾に塩分が
存在する場合の耐食性に優れた鉄筋に関するもの
を第１発明とし、機械的特性、特に低温靭性の一
層の向上を考慮してNb，Ｖを添加し、又コンク
リートに打設されるまでの耐候性を保証するため
にCuを適宜添加したものをその他の発明として
いる。 Furthermore, it is used with a galvanized coating if necessary, and is related to reinforcing bars that have excellent corrosion resistance in the corrosive environment where salt is present in the high PH range of concrete mentioned above, and have excellent toughness at extremely low temperatures. C: 0.05-1.0%, Si: 0.055-0.20
%, Mn: 0.20-1.2%, P: 0.005-0.025%,
Contains S: 0.0005 to 0.003%, Al: 0.001 to 0.08% and Ca: 0.0002 to less than 0.0005%, and further contains Ni
The first invention relates to a reinforcing bar containing 3 to 5.5% of iron, with the balance being iron and unavoidable impurities, and which has excellent corrosion resistance when salt is present in the concrete width around PH12. Other inventions are those in which Nb and V are added in consideration of further improvement, and Cu is appropriately added in order to ensure weather resistance until it is poured into concrete.
本発明は極低温で靭性が保証されているNiを
３〜5.5％含有する鋼を基本とし、これにCaを添
加して、鋼中のＳを著るしく低下させると同時に
鋼中のSi量を低下させ、且つ鋼中のＰ量も低下さ
せて、鉄筋表面の被膜中で塩分の被膜損傷を誘発
する硫化物の化学的特性をより耐塩性の強いもの
に変化させると同時に、被膜中に存在するSi化合
物、Ｐ化合物の量を比較的低下させて、高PH値の
コンクリート中で耐塩性に優れた不働態被膜を形
成させる点にその特徴がある。 The present invention is based on a steel containing 3 to 5.5% Ni, whose toughness is guaranteed at extremely low temperatures, and by adding Ca to this, the S content in the steel is significantly reduced, while at the same time the amount of Si in the steel is reduced. By lowering the amount of P in the steel and changing the chemical properties of sulfides that induce salt damage in the coating on the reinforcing bar surface to more salt-resistant ones, it also reduces the amount of P in the coating. Its feature is that it relatively reduces the amount of Si compounds and P compounds present, forming a passive film with excellent salt resistance in concrete with a high pH value.
従つて、鋼中のSi量とＰ量を低下させ、Ｓ量を
可能なかぎり低下させ、且つ硫化物の性状を変え
るためにCaを３〜5.5％Ni鋼に比較的少量添加し
たことが最大の特徴であるが、本発明の狙いはコ
ンクリートのようにPH12前後の高PH領域で塩分が
存在する場合の低温用鋼の中Ni鋼に焦点を合わ
せていることである。 Therefore, in order to reduce the amount of Si and P in the steel, reduce the amount of S as much as possible, and change the properties of sulfides, the most important thing to do is to add a relatively small amount of Ca to 3-5.5% Ni steel. However, the aim of the present invention is to focus on medium Ni steel, which is a steel for low temperature use when salt is present in the high pH range of around 12, such as in concrete.
以下にその詳細について述べる共に、前記のよ
うに本発明の鉄筋の成分範囲を定めた理由を説明
する。 The details will be described below, and the reason why the component range of the reinforcing bar of the present invention was determined as described above will be explained.
ＣはMn量の上限を1.2％に規定した場合、機械
的強度の上昇に必須であるので上限を1.0％とし
た。又下限を0.05％としたのは鉄筋としての強度
を確保するためである。 When the upper limit of the Mn content is set at 1.2%, C is essential for increasing mechanical strength, so the upper limit is set at 1.0%. The lower limit was set to 0.05% in order to ensure the strength of the reinforcing bar.
Siはコンクリートに埋め込まれた鉄筋表面の不
動態被膜を劣化させる傾向があるので、可能なか
ぎり低下させることが望ましいが、極低温で靭性
を向上させるためにはシリケート等の介在物の形
状を好ましい形に制御する必要がある。従つて極
端にSi量を低下させることはできない。この観点
から下限を0.055％とし上限を0.2％とした。 Si tends to deteriorate the passive film on the surface of reinforcing bars embedded in concrete, so it is desirable to reduce it as much as possible, but in order to improve toughness at extremely low temperatures, it is preferable to change the shape of inclusions such as silicate. It is necessary to control the shape. Therefore, it is not possible to reduce the amount of Si extremely. From this point of view, the lower limit was set to 0.055% and the upper limit was set to 0.2%.
Mnは一般に鋼の強度上昇と硫化物生成に寄与
することが知られている。硫化物としてはコンク
リート中に埋め込まれた鉄筋表面の不働態被膜を
破壊する起点となる硫化マンガン等の硫化物は可
能なかぎり少ない方が好ましい。従つてMn量は
低い方が望ましいが、必要な機械的強度を確保す
るために下限を0.20％とし、上限を1.2％とし
た。 Mn is generally known to contribute to increasing the strength of steel and generating sulfides. As for sulfides, it is preferable that the amount of sulfides such as manganese sulfide, which becomes a starting point for destroying the passive film on the surface of reinforcing bars embedded in concrete, be as small as possible. Therefore, a lower Mn content is desirable, but in order to ensure the necessary mechanical strength, the lower limit was set to 0.20% and the upper limit was set to 1.2%.
Ｐは一般的に耐海水性を向上する元素として知
られているが、コンクリートのように高PH値で塩
分が存在する場合にはＰの量の増加にともなつて
必らずしも耐塩性は向上しない。しかもＰの量を
増すと溶接性を劣化させる。従つて下限を0.005
％とし上限を0.025％とした。 P is generally known as an element that improves seawater resistance, but in cases where salt is present at a high PH value, such as in concrete, increasing the amount of P does not necessarily improve salt resistance. does not improve. Moreover, increasing the amount of P deteriorates weldability. Therefore, the lower limit is 0.005
% with an upper limit of 0.025%.
Ｓは前述のようにコンクリート中の塩分による
不働態被膜の破壊を招くので可能な限り低下させ
ることが望ましい。しかし0.0005％以下に低下さ
せることは経済的に不利である。従つて下限を
0.0005％、上限を0.003％とした。最も好ましい
範囲は0.001〜0.002％である。 As mentioned above, S causes destruction of the passive film due to salt in concrete, so it is desirable to reduce it as much as possible. However, reducing the content to below 0.0005% is economically disadvantageous. Therefore, the lower limit
0.0005%, with an upper limit of 0.003%. The most preferred range is 0.001-0.002%.
Alは耐食性とは本質的に関係がないが鋳造法
の相違による脱酸力調整のため低下させたもの
で、下限はリムド鋼ベースのものを考慮して
0.001％とし、上限は連鋳材等でAlを多量に添加
することを考慮して0.08％とした。 Although Al is essentially unrelated to corrosion resistance, it was lowered to adjust the deoxidizing power due to differences in casting methods, and the lower limit is based on rimmed steel-based products.
It was set at 0.001%, and the upper limit was set at 0.08% in consideration of the fact that a large amount of Al is added in continuous casting materials.
Ca添加の最大の狙いは、鋼中の脱硫によりＳ
量を著しく低減させることにあるが、同時にMn
量が高い場合でも残存する酸化物が完全なα
MnSになることを避け、Caを含む硫化物に変化
させてその化学的性状を変化させ、耐塩性が向上
することを期待して添加したものである。下限は
必要最少限の含有量であり、上限は硫化物の性状
を耐塩性に好ましいものに変化させるためで、
0.0002〜0.0005％未満の範囲とした。 The main aim of adding Ca is to desulfurize the steel and reduce the S content.
The aim is to significantly reduce the amount of Mn, but at the same time
Even when the amount of remaining oxide is high, the remaining oxide is completely α
It was added in the hope that it would avoid turning into MnS, change its chemical properties to a sulfide containing Ca, and improve its salt tolerance. The lower limit is the minimum necessary content, and the upper limit is to change the properties of sulfide to one favorable for salt resistance.
The range was 0.0002% to less than 0.0005%.
Niは本発明の基本的思想の一つである極低温
での靭性を保証するための必須元素であり、３％
未満では−120〜−160℃での低温靭性が保証され
ず5.5％超では経済性の点で不利になるのでNi量
の範囲を３〜5.5％に規定したものである。 Ni is an essential element to ensure toughness at extremely low temperatures, which is one of the basic ideas of the present invention, and 3%
If it is less than 5.5%, the low-temperature toughness at -120 to -160°C is not guaranteed, and if it exceeds 5.5%, it will be disadvantageous in terms of economic efficiency.
Nb，Ｖの単独又は複合添加は高張力で且つ低
温靭性を向上させるためのもので、機械的強度と
靭性向上を高めるために、析出硬化と細粒効果を
目的とした炭窒化物生成元素を添加したものであ
る。合計量の下限を0.005％としたのは、これ以
下ではその効果が認められないためであり、上限
を0.2％としたのはこれ以上では鋼の脆化をもた
らすためである。 Addition of Nb and V alone or in combination is to improve high tensile strength and low-temperature toughness.In order to improve mechanical strength and toughness, carbonitride forming elements are added for precipitation hardening and fine grain effect. It was added. The lower limit of the total amount was set at 0.005% because the effect is not recognized below this, and the upper limit was set at 0.2% because above this the steel becomes brittle.
Cuの添加は耐候性を必要とした場合を考慮し
たもので、下限はその効果の現われる最小必要量
で、上限は鋼の脆化をもたらす量をしめており、
0.03〜0.5％とした。 The addition of Cu takes into consideration the case where weather resistance is required, and the lower limit is the minimum amount necessary for the effect to appear, and the upper limit is the amount that causes embrittlement of the steel.
It was set at 0.03-0.5%.
本発明に従い前記の化学成分で構成された鋼は
転炉、電気炉、平炉等で溶製され、次いで造塊、
分塊の工程を経るか、あるいは連続鋳造後、圧延
された後に、必要に応じてパテンテイング等の熱
処理が施され、線引きされて鉄筋として供され
る。又必要に応じて表面に亜鉛メツキ被覆を施す
こともできる。 According to the present invention, the steel composed of the above chemical components is melted in a converter, electric furnace, open hearth, etc., and then ingot-formed,
After going through the blooming process or after being continuously cast and rolled, it is subjected to heat treatment such as patenting as necessary, and then drawn into wire and used as reinforcing bars. Additionally, the surface may be galvanized if necessary.
実施例 １
第１表に電炉で本発明の成分範囲の鋼を溶製
し、造塊、分塊後、線引きした鉄筋と従来鋼から
なる鉄筋との成分および腐食試験結果を示した。Example 1 Table 1 shows the composition and corrosion test results of reinforcing bars made of steel having the composition range of the present invention in an electric furnace, ingot-formed, bloomed, and drawn, and reinforcing bars made of conventional steel.
第１表に示した鉄筋の中央部より巾25mm×長さ
60mm×厚さ２mmの試片を採取し、機械研削して表
面を研磨した。 Width 25mm x length from the center of the reinforcing bars shown in Table 1
A specimen of 60 mm x 2 mm thickness was taken and mechanically ground to polish the surface.
他方コンクリートの主成分であるCaOを0.2％
NaCl水溶液中に溶解させてPH12のCa（OH）2＋
NaCl水溶液を準備した。 On the other hand, CaO, the main component of concrete, is 0.2%.
Ca(OH) 2 + at pH 12 dissolved in NaCl aqueous solution
A NaCl aqueous solution was prepared.
しかる後、前記のように表面研削し、側面と裏
面をシリコンゴムレジンで被覆した試験片を、ベ
ンゾール脱脂、アセトン脱脂後、乾燥し、直ちに
上記のCa（OH）2＋NaCl水溶液中に浸漬した。 Thereafter, the test piece whose surface was ground as described above and whose side and back surfaces were coated with silicone rubber resin was degreased with benzol and acetone, dried, and immediately immersed in the above Ca(OH) 2 +NaCl aqueous solution.
なお液の表面を流動パラフインでシールし、３
日毎に液を置換して20日間連続浸漬し、錆の発生
状況を観察した。 Seal the surface of the liquid with liquid paraffin, and
The liquid was replaced every day and the samples were immersed continuously for 20 days, and the state of rust formation was observed.
表中、(A)は錆の発生の有無、表中(B)は局部腐食
の深さ（mm）を示す。 In the table, (A) indicates the presence or absence of rust, and (B) in the table indicates the depth (mm) of local corrosion.
なお、参考までにこれら試片の若干のものにつ
いて前述のPH12のCa（OH）2＋NaCl水溶液中の陽
分極特性をしらべた。その結果を第１図に示す。
第１図より第１表で錆発生のみとめられなかつた
ものは、錆発生の認められたものより電位が貴で
あることがわかる。これはコンクリートのような
高Ph領域の液中で生成する鉄筋の不働態被膜
が、NaClによつて破壊され難い現象を証明して
いる。 For reference, the anodic polarization characteristics of some of these specimens in the aforementioned PH12 Ca(OH) 2 +NaCl aqueous solution were investigated. The results are shown in FIG.
From FIG. 1, it can be seen that the potential of the specimens in Table 1 in which no rust was detected was higher than that of the specimens in which rust was observed. This proves that the passive film of reinforcing steel, which is formed in high pH liquids such as concrete, is difficult to be destroyed by NaCl.
実施例 ２
砂中のNaCl（％）を0.2％とした塩分を含んだ
砂、ポルトランドセメント、水、砂利からなるコ
ンクリートモルタルに第１表の成分からなる鉄筋
（９mmφ）をうめ込み、28日間常温養生した後、
海浜地帯に１年間曝露した。Example 2 Reinforcing bars (9 mmφ) made of the ingredients shown in Table 1 were embedded in a concrete mortar made of sand containing salt containing 0.2% NaCl (%), Portland cement, water, and gravel, and kept at room temperature for 28 days. After curing,
Exposure to beach area for 1 year.
なおコンクリートの水、セメント比は0.65、カ
ブリ厚さは２cmとした。また鉄筋は熱間圧延鉄筋
である。 The water-to-cement ratio of the concrete was 0.65, and the fog thickness was 2 cm. The reinforcing bars are hot rolled reinforcing bars.
１年間曝露後、コンクリートを砕砕して鉄筋の
発錆状況を調べた。その結果を第１表(C)に示す。 After one year of exposure, the concrete was crushed and the rusting status of the reinforcing bars was examined. The results are shown in Table 1 (C).
第１図はCa（OH）2＋0.2％NaCl水溶液（PH
12）中で25℃において測定した供試鋼の陽分極特
性を示したものである。
Figure 1 shows Ca(OH) 2 + 0.2% NaCl aqueous solution (PH
12) shows the positive polarization characteristics of the test steel measured at 25°C.
Claims (1)
コンクリート中に塩分が存在する場合の耐食性に
優れ、且つ低温で靭性の優れたコンクリート用鉄
筋。 ２ Ｃ ：0.05〜1.0％、 Si：0.055〜0.20％、 Mn：0.20〜1.2％、 Ｐ ：0.005〜0.025％、 Ｓ ：0.0005〜0.003％ Al：0.001〜0.08％、 Ca：0.0002〜0.0005％未満、 Ni：３〜5.5％ を含有し、さらに Cuを0.03〜0.5％ 含有し、残部鉄および不可避的不純物からなり、
コンクリート中に塩分が存在する場合の耐食性に
優れ、且つ低温で靭性の優れたコンクリート用鉄
筋。 ３ Ｃ ：0.05〜1.0％、 Si：0.055〜0.20％、 Mn：0.20〜1.2％、 Ｐ ：0.005〜0.025％、 Ｓ ：0.0005〜0.003％、 Al：0.001〜0.08％、 Ca：0.0002〜0.0005％未満、 Ni：３〜5.5％ を含有し、さらに Nb，Ｖを単独ないし複合添加で合計量を0.005
〜0.2％ 含有し、残部鉄および不可避的不純物からなり、
コンクリート中に塩分が存在する場合の耐食性に
優れ、且つ低温で靭性の優れたコンクリート用鉄
筋。 ４ Ｃ ：0.05〜1.0％、 Si：0.055〜0.20％、 Mn：0.20〜1.2％、 Ｐ ：0.005〜0.025％、 Ｓ ：0.0005〜0.003％、 Al：0.001〜0.08％、 Ca：0.0002〜0.0005％未満、 Ni：３〜5.5％ を含有し、さらに Nb，Ｖを単独ないし複合添加で合計量を0.005
〜0.2％ および Cuを0.03〜0.5％ 含有し、残部鉄および不可避的不純物からなり、
コンクリート中に塩分が存在する場合の耐食性に
優れ、且つ低温で靭性の優れたコンクリート用鉄
筋。[Claims] 1 C: 0.05-1.0%, Si: 0.055-0.20%, Mn: 0.20-1.2%, P: 0.005-0.025%, S: 0.0005-0.003%, Al: 0.001-0.08%, Ca : Contains 0.0002 to less than 0.0005%, further contains 3 to 5.5% Ni, and the balance consists of iron and unavoidable impurities.
A reinforcing bar for concrete that has excellent corrosion resistance when salt is present in concrete and has excellent toughness at low temperatures. 2 C: 0.05-1.0%, Si: 0.055-0.20%, Mn: 0.20-1.2%, P: 0.005-0.025%, S: 0.0005-0.003% Al: 0.001-0.08%, Ca: 0.0002-less than 0.0005%, Contains 3 to 5.5% Ni, further contains 0.03 to 0.5% Cu, and the balance consists of iron and inevitable impurities.
A reinforcing bar for concrete that has excellent corrosion resistance when salt is present in concrete and has excellent toughness at low temperatures. 3C: 0.05-1.0%, Si: 0.055-0.20%, Mn: 0.20-1.2%, P: 0.005-0.025%, S: 0.0005-0.003%, Al: 0.001-0.08%, Ca: 0.0002-less than 0.0005% , Ni: 3 to 5.5%, and Nb and V can be added singly or in combination to bring the total amount to 0.005%.
~0.2%, with the balance consisting of iron and unavoidable impurities.
A reinforcing bar for concrete that has excellent corrosion resistance when salt is present in concrete and has excellent toughness at low temperatures. 4 C: 0.05-1.0%, Si: 0.055-0.20%, Mn: 0.20-1.2%, P: 0.005-0.025%, S: 0.0005-0.003%, Al: 0.001-0.08%, Ca: 0.0002-less than 0.0005% , Ni: 3 to 5.5%, and Nb and V can be added singly or in combination to bring the total amount to 0.005%.
~0.2% and 0.03~0.5% Cu, with the balance consisting of iron and unavoidable impurities.
A reinforcing bar for concrete that has excellent corrosion resistance when salt is present in concrete and has excellent toughness at low temperatures.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17243580A JPS5798653A (en) | 1980-12-06 | 1980-12-06 | Salt-proof reinforcing rod for concrete for low temperature use |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17243580A JPS5798653A (en) | 1980-12-06 | 1980-12-06 | Salt-proof reinforcing rod for concrete for low temperature use |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5798653A JPS5798653A (en) | 1982-06-18 |
| JPS623222B2 true JPS623222B2 (en) | 1987-01-23 |
Family
ID=15941921
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17243580A Granted JPS5798653A (en) | 1980-12-06 | 1980-12-06 | Salt-proof reinforcing rod for concrete for low temperature use |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5798653A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100489025B1 (en) * | 2000-11-25 | 2005-05-11 | 주식회사 포스코 | Seaside corrosion resistance steel with superior tensile strength and method for manufacturing it |
| CN106222561B (en) * | 2016-08-30 | 2018-03-27 | 日照钢铁控股集团有限公司 | Method based on ESP bar strip continuous casting and rolling flow paths production low-carbon fire-fighting equipment steel |
-
1980
- 1980-12-06 JP JP17243580A patent/JPS5798653A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5798653A (en) | 1982-06-18 |
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