JPH03211230A - Production of low alloy steel for line pipe with high corrosion resistance - Google Patents
Production of low alloy steel for line pipe with high corrosion resistanceInfo
- Publication number
- JPH03211230A JPH03211230A JP2005263A JP526390A JPH03211230A JP H03211230 A JPH03211230 A JP H03211230A JP 2005263 A JP2005263 A JP 2005263A JP 526390 A JP526390 A JP 526390A JP H03211230 A JPH03211230 A JP H03211230A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- toughness
- low
- less
- corrosion resistance
- 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
- 230000007797 corrosion Effects 0.000 title claims abstract description 21
- 238000005260 corrosion Methods 0.000 title claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 229910000851 Alloy steel Inorganic materials 0.000 title abstract 3
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 39
- 239000010959 steel Substances 0.000 claims abstract description 39
- 238000005096 rolling process Methods 0.000 claims abstract description 20
- 238000001816 cooling Methods 0.000 claims abstract description 12
- 230000001186 cumulative effect Effects 0.000 claims abstract description 7
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 4
- 229910052742 iron Inorganic materials 0.000 claims abstract description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 4
- 239000000956 alloy Substances 0.000 claims 2
- 229910045601 alloy Inorganic materials 0.000 claims 2
- 238000000034 method Methods 0.000 abstract description 5
- 229910052748 manganese Inorganic materials 0.000 abstract description 4
- 239000000203 mixture Substances 0.000 abstract description 4
- 229910052758 niobium Inorganic materials 0.000 abstract description 4
- 229910052698 phosphorus Inorganic materials 0.000 abstract description 3
- 229910052717 sulfur Inorganic materials 0.000 abstract description 3
- 229910052719 titanium Inorganic materials 0.000 abstract description 3
- 229910052791 calcium Inorganic materials 0.000 abstract description 2
- 229910052802 copper Inorganic materials 0.000 abstract description 2
- 238000005098 hot rolling Methods 0.000 abstract description 2
- 229910052759 nickel Inorganic materials 0.000 abstract description 2
- 229910052720 vanadium Inorganic materials 0.000 abstract description 2
- 229910052782 aluminium Inorganic materials 0.000 abstract 2
- 229910052804 chromium Inorganic materials 0.000 abstract 2
- 229910052757 nitrogen Inorganic materials 0.000 abstract 2
- 229910052710 silicon Inorganic materials 0.000 abstract 2
- 230000002542 deteriorative effect Effects 0.000 abstract 1
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 239000010953 base metal Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- 239000000463 material Substances 0.000 description 6
- 238000003303 reheating Methods 0.000 description 6
- 238000005336 cracking Methods 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 238000004881 precipitation hardening Methods 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 230000003749 cleanliness Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000010779 crude oil Substances 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は耐ＣＯ２腐食性の優れたラインパイプ用高張力
鋼板（引張強さ：ＴＳで５０ｋｇｆ／ｍＪ以上、厚み４
０１層以下）の製造法に関するものである。Detailed Description of the Invention (Field of Industrial Application) The present invention is a high tensile strength steel plate for line pipes with excellent CO2 corrosion resistance (tensile strength: 50 kgf/mJ or more in TS, thickness 4
01 layer or less).
鉄鋼業においては厚板ミルに適用することがもっとも好
ましいが、ホットコイルにも適用できる。また、この方
法で製造した鋼板は低温靭性、現地溶接性も優れている
ので、寒冷地やオフショアにおける使用にもっとも適す
る。In the steel industry, it is most preferably applied to plate mills, but it can also be applied to hot coils. In addition, the steel sheets manufactured by this method have excellent low-temperature toughness and on-site weldability, making them most suitable for use in cold regions and offshore.
（従来の技術）
寒冷地やオフショアにおける石油、ガス輸送用大径ライ
ンパイプに対しては高強度とともに優れた低温靭性、現
地溶接性が要求される。さらに最近では、原油の２次、
３次回収におけるＣＯ□注入や深井戸化によるインヒビ
ター効果の低下などによって、ＣＯ２ガスによるライン
パイプの腐食が大きな問題となっていることから、耐Ｃ
Ｏ２腐食性も併せて要求されるようになった。(Conventional technology) Large-diameter line pipes for oil and gas transportation in cold regions and offshore require high strength, excellent low-temperature toughness, and on-site weldability. More recently, secondary crude oil,
Corrosion of line pipes due to CO2 gas has become a major problem due to CO□ injection in tertiary recovery and the decline in inhibitor effect due to deeper wells, so C-resistant
O2 corrosive properties are also required.
しかし現在、ＣＯ２腐食に対してはＣｒ添加が有効との
知見はあるものの（石油技術協会誌第５０巻、第２号図
９．１０） 、低温環境に完全に適合した耐ＣＯ２腐食
大径ラインパイプは開発されるに至っていない。However, although there is currently knowledge that adding Cr is effective against CO2 corrosion (Journal of Japan Petroleum Technology Society Vol. 50, No. 2, Figure 9.10), there is a large-diameter CO2 corrosion-resistant line that is completely suitable for low-temperature environments. Pipes have not yet been developed.
すなわちＣ「を多量に添加し耐食性を改善した鋼は数多
く開発されているが（例えば特公昭５９−１９１７９号
、特公昭５９−４５７５０号各公報）、低温用ラインパ
イプとしての優れた低温靭性、現地溶接性を兼備えた鋼
は存在しない。In other words, many steels have been developed that have improved corrosion resistance by adding a large amount of C (for example, Japanese Patent Publication No. 19179/1979 and Japanese Patent Publication No. 45750/1986), but they have excellent low temperature toughness for low temperature line pipes, There is no steel that has on-site weldability.
Ｃ「の多量添加は溶接性を害するので、現地溶接時に溶
接割れ防止の観点から高温での予熱、後熱処理が必須と
なり、施工能率を著しく低下させる。また多量のＣ「添
加は母材、溶接熱影響部（ＨＡＺ）の靭性を劣化させる
。このため耐ＣＯ２腐食性が優れ、かつ良好な低温靭性
、現地溶接性を有するラインパイプ用鋼の開発が強く望
まれている。Addition of a large amount of C impairs weldability, so preheating and post-heat treatment at high temperatures are required to prevent weld cracking during on-site welding, which significantly reduces construction efficiency. It deteriorates the toughness of the heat-affected zone (HAZ).For this reason, there is a strong desire to develop steel for line pipes that has excellent CO2 corrosion resistance, good low-temperature toughness, and on-site weldability.
（発明が解決しようとする課題）
本発明は母材、ＨＡＺの低温靭性および現地溶接性を損
なうことなく、耐ＣＯ２腐食性を大幅に改善した新しい
ラインパイプ用鋼の製造法を与えるものである。(Problems to be Solved by the Invention) The present invention provides a new method for manufacturing line pipe steel that has significantly improved CO2 corrosion resistance without impairing the low-temperature toughness and on-site weldability of the base metal, HAZ. .
（課題を解決するための手段）
本発明の要旨は、重量％でＣ： ０．０２〜０．０９、
Ｓ ｉ：０．５以下、Ｍｎ：０．７〜１．５、Ｐ ：
０．０３以下、Ｓ ：０．００５以下、Ｎｂ：０．０２
〜ｏ、ｏｅ、Ｃｒ：０．５〜１．２以下、Ｔｉ：０．０
０５〜０．０３、ＡｌＯ，０５以下、Ｎ：（１，００２
〜０．００５１．：必要に応じて、さら１．： Ｖ ：
［１，０１〜０．０８、Ｎ ｉ：ｏ、０５〜０．５、
Ｃｕ：０．０５〜０．５、Ｃａ：０．００１〜０．００
５を含有し、かつ０．３５≦Ｃ＋（Ｍｎ＋Ｃｒ＋Ｖ）１
５＋ （Ｎ１＋Ｃｕ）／１５≦０．４８を満足する残部
が鉄および不可避的不純物からなる鋼を１１００℃〜１
２５０℃の温度範囲に加熱して、９５０℃以下の累積圧
下量４０％以上、圧延終了温度７００℃〜８５０℃で圧
延を行なった後、空冷または加速冷却することである。(Means for Solving the Problems) The gist of the present invention is that C: 0.02 to 0.09 in weight%,
Si: 0.5 or less, Mn: 0.7-1.5, P:
0.03 or less, S: 0.005 or less, Nb: 0.02
~o, oe, Cr: 0.5 to 1.2 or less, Ti: 0.0
05-0.03, AlO, 05 or less, N: (1,002
~0.0051. :Additional steps 1. as necessary. : V :
[1,01-0.08, N i:o, 05-0.5,
Cu: 0.05-0.5, Ca: 0.001-0.00
5 and 0.35≦C+(Mn+Cr+V)1
5+ (N1+Cu)/15≦0.48 and the remainder consists of iron and unavoidable impurities at 1100℃~1
After heating to a temperature range of 250°C and rolling at a cumulative reduction of 40% or more at 950°C or less and a rolling end temperature of 700°C to 850°C, air cooling or accelerated cooling is performed.
以下、本発明について詳細に説明する。The present invention will be explained in detail below.
耐ＣＯ２腐食性を改善し、かつ優れた母材、ＨＡＺの低
温靭性、現地溶接性を得るためには、その科学成分を限
定する必要がある。このため、まず耐食性の面からＣｒ
量を０．５〜１．２％とした。In order to improve CO2 corrosion resistance and obtain excellent base metal, HAZ low temperature toughness and field weldability, it is necessary to limit its chemical composition. For this reason, first of all, from the viewpoint of corrosion resistance, Cr
The amount was set at 0.5-1.2%.
十分な耐食性を得るために、Ｃｒ量は最低０．５％必要
である。しかし多過ぎると低温靭性、現地溶接性を大き
く劣化させるので、その上限を１．２％とした。In order to obtain sufficient corrosion resistance, the amount of Cr must be at least 0.5%. However, if the content is too high, low-temperature toughness and on-site weldability will be significantly degraded, so the upper limit was set at 1.2%.
耐食性の改善から相当量のＣｒを添加し、優れた低温靭
性、溶接性を確保するには、Ｃ： ０．０２〜０．０９
％、Ｍｎ：０．７〜１．５％とする必要があるＯＣ＋Ｍ
ｎの下限は必要とする母材、溶接部強度やＮｂ。Adding a considerable amount of Cr to improve corrosion resistance and ensure excellent low temperature toughness and weldability requires C: 0.02 to 0.09.
%, Mn: OC+M which needs to be 0.7-1.5%
The lower limit of n depends on the required base material, weld strength and Nb.
■添加時にこれらの元素が析出硬化、結晶粒微細化効果
を達成するための最小量である。また上限は優れた低温
靭性、現地溶接性を得るための限界値である（とくに望
ましいＣ，Ｍｎ量は、それぞれ０．０３〜０．０６％、
０．８〜１．２％である）。(2) When added, these elements are present in the minimum amount to achieve precipitation hardening and grain refinement effects. In addition, the upper limit is the limit value for obtaining excellent low-temperature toughness and on-site weldability (particularly desirable C and Mn contents are 0.03 to 0.06%, respectively,
0.8-1.2%).
しかし、個々の量を限定するだけでは不十分であり、０
．３５％≦（＋ （Ｍｎ＋Ｃｒ＋Ｖ）１５＋（Ｎｉ＋Ｃ
ｕ）／１５≦０，４８としなければならない。However, it is not enough to limit the amount of each individual, and 0
．． 35%≦(+ (Mn+Cr+V)15+(Ni+C
u)/15≦0,48.
これは低温靭性や現地溶接性がＣｒを含めた化学成分の
全量で決まるからである。下限の０．３５％は必要な母
材、溶接部の強度を得るための最小量であり、０．４８
％は優れた低温靭性、溶接性を得るための上限である。This is because low-temperature toughness and on-site weldability are determined by the total amount of chemical components including Cr. The lower limit of 0.35% is the minimum amount to obtain the necessary base metal and weld strength, and 0.48
% is the upper limit for obtaining excellent low temperature toughness and weldability.
本発明鋼は必須の元素としてＮｂ：０．０２〜０．０６
％、Ｔ ｉ：０．００５〜０．０３％を含有する。Ｎｂ
は制御圧延における結晶粒の微細化や析出硬化に寄与し
、鋼を強靭化する。またＴ１添加は微細なＴｉＮを形成
し、スラブ加熱時、溶接時のγ粒粗大化を抑制して母材
靭性、ＨＡＺ靭性の改善に効果がある。The steel of the present invention has Nb as an essential element: 0.02 to 0.06
%, Ti: 0.005 to 0.03%. Nb
contributes to grain refinement and precipitation hardening during controlled rolling, making the steel tougher. Furthermore, addition of T1 forms fine TiN, suppresses coarsening of γ grains during slab heating and welding, and is effective in improving base metal toughness and HAZ toughness.
Ｃ「を多量添加すると制御圧延鋼でもシャルピー試験な
どの衝撃破面にセパレーションが発生しにくくなり、低
温靭性の劣化をきたすので、とくに低Ｃ１低Ｍｎの本発
明鋼では、低温靭性確保の点からＮｂ、ＴＩ添加は必須
であることがわかった。If a large amount of C is added, separation will be difficult to occur on the impact fracture surface in Charpy test etc. even in controlled rolled steel, and the low temperature toughness will deteriorate. It was found that addition of Nb and TI is essential.
Ｎｂ、ＴＩ量の下限は、これらの元素がその効果を発揮
するための最小量であり、その上限はＨＡＺ靭性や現地
溶接性を劣化させない添加量の限界である。The lower limit of the amount of Nb and TI is the minimum amount for these elements to exhibit their effects, and the upper limit is the limit of the amount of addition that does not deteriorate HAZ toughness or on-site weldability.
つぎにその他元素の限定理由について説明する。Next, the reasons for limiting other elements will be explained.
Ｓｌは多く添加すると溶接性、ＨＡＺ靭性を劣化させる
ため、上限を０．５％とした。鋼の脱酸はＴｉのみでも
十分であり、Ｓｉはかならずしも添加する必要はない。Since adding a large amount of Sl deteriorates weldability and HAZ toughness, the upper limit was set at 0.5%. Ti alone is sufficient for deoxidizing steel, and it is not always necessary to add Si.
本発明鋼において不純物であるＰ、Ｓをそれぞれ０．０
３％、 ０．００５％以下とした理由は、母材、溶接部
の低温靭性をより一層向上させるためである。Ｐの低減
は粒界破壊を防止し、Ｓ量の低減はＭｎＳによる靭性の
劣化を防止する。好ましいＰ。In the steel of the present invention, the impurities P and S are each 0.0
The reason for setting the content to 3% and 0.005% or less is to further improve the low-temperature toughness of the base metal and weld zone. Reducing the amount of P prevents grain boundary fracture, and reducing the amount of S prevents deterioration of toughness due to MnS. Preferred P.
Ｓ量はそれぞれ０．０１．０．００３％以下である。The amount of S is 0.01% and 0.003% or less, respectively.
Ａ、Ｑは通常脱酸剤として綱に含まれる元素であるが、
脱酸はＴＩあるいはｓｌでも可能であり、必ずしも添加
する必要はない。Ａｌ量が０．０５％超になるとＡＩ系
非金属介在物が増加して鋼の清浄度を害するので、上限
を０．０５％とした。A and Q are elements normally included in the class as deoxidizing agents,
Deoxidation can be done with TI or sl, and it is not necessary to add TI or sl. If the Al amount exceeds 0.05%, AI-based nonmetallic inclusions will increase and impair the cleanliness of the steel, so the upper limit was set at 0.05%.
ＮはＴｉＮを形成しγ粒の粗大化抑制効果を通じて母材
、ＨＡＺ靭性を向上させる。このための最小量は０．０
０２％である。しがし多過ぎるとスラブ表面疵や固溶Ｎ
によるＨＡＺ靭性劣化の原因となるので、その上限はｏ
、ｏｏｓ％以下に抑える必要がある。N forms TiN and improves the toughness of the base material and HAZ through the effect of suppressing coarsening of γ grains. The minimum amount for this is 0.0
It is 02%. Too much scrubbing may cause slab surface flaws or solid solution N.
This causes deterioration of HAZ toughness due to
, oos% or less.
ツキにＶ、Ｎｉ 、Ｃｕ、Ｃａを添加する理由について
説明する。The reason why V, Ni, Cu, and Ca are added to the coating will be explained.
基本となる成分に、さらにこれらの元素を添加する主た
る目的は、本発明鋼の優れた特徴を損なうことなく、強
度、靭性などの特性向上をはがるためである。したがっ
て、その添加量は自ら制限されるべき性質のものである
。The main purpose of adding these elements to the basic components is to improve properties such as strength and toughness without impairing the excellent characteristics of the steel of the present invention. Therefore, the amount added should be limited.
■はほぼＮｂと同様な効果を有し、ミクロ組織の微細化
による低温靭性の向上や焼入性の増大、析出硬化による
高強度化などの効果がある。しかし、添加量が多過ぎる
と溶接性やＨＡＺ靭性の劣化を招くので、その上限を０
．０８％とした。(2) has almost the same effects as Nb, and has effects such as improving low-temperature toughness and hardenability by refining the microstructure, and increasing strength by precipitation hardening. However, if the amount added is too large, it will cause deterioration of weldability and HAZ toughness, so the upper limit should be set to 0.
．． It was set at 08%.
Ｎｉは溶接性、ＨＡＺ靭性に悪影響をおよぼすことなく
、強度、靭性をともに向上させるほか、Ｃｕ添加時の熱
間割れ防止にも効果がある。しかし０．５％を超えると
経済性の点で好ましくないため、その上限を０．５％と
した。Ni improves both strength and toughness without adversely affecting weldability and HAZ toughness, and is also effective in preventing hot cracking when Cu is added. However, if it exceeds 0.5%, it is unfavorable from an economic point of view, so the upper limit was set at 0.5%.
Ｃｕは耐食性、耐水素誘起割れ性にも効果があるが、０
．５％を超えると熱間圧延時にＣｕ−クラックが生じ、
製造が困難になる。このため上限を０．５％とした。Cu is also effective in corrosion resistance and hydrogen-induced cracking resistance, but
．． If it exceeds 5%, Cu-cracks will occur during hot rolling,
Manufacturing becomes difficult. For this reason, the upper limit was set at 0.5%.
Ｃａは硫化物（ＭｎＳ）の形態を制御し、低温靭性を向
上（シャルピー吸収エネルギーの増加など）させるほか
、耐水素誘起割れ性の改善にも著しい効果を発揮する。Ca controls the morphology of sulfide (MnS), improves low-temperature toughness (increases Charpy absorbed energy, etc.), and has a remarkable effect on improving hydrogen-induced cracking resistance.
しかしＣａ量が０．００１％以下では実用上効果がなく
、また０、００５％を超えて添加すると、Ｃａｂ、Ｃａ
５が大量に生成して大型介在物となり、鋼の清浄度を害
するだけでなく靭性、現地溶接性に悪影響をおよぼす。However, if the amount of Ca is less than 0.001%, it has no practical effect, and if it exceeds 0.005%, Ca, Ca
5 is generated in large quantities and becomes large inclusions, which not only impair the cleanliness of the steel but also adversely affect the toughness and on-site weldability.
このためＣａ添加量を０．００１−０．００５％に制限
した。なお耐水素誘起割れ性を改善するにはＳ。For this reason, the amount of Ca added was limited to 0.001-0.005%. Note that S is used to improve hydrogen-induced cracking resistance.
０量をそれぞれ０．００１．０．００２％以下に低減し
、Ｅ Ｓ Ｓ Ｐ≧（Ｃａ） （１−１２４（０） 〕
／１．２５ （Ｓ）とすることがとくに有効である。0 amount to 0.001.0.002% or less, respectively, and E S S P ≧ (Ca) (1-124 (0))
/1.25 (S) is particularly effective.
上記のようなＣｒ添加鋼において、母材の低温靭性を改
善するためには、さらに製造法が適切でなければならず
、鋼（スラブ）の再加熱、圧延、冷却条件を限定する必
要がある。In order to improve the low-temperature toughness of the base metal in the above-mentioned Cr-added steel, the manufacturing method must be more appropriate, and the reheating, rolling, and cooling conditions of the steel (slab) must be limited. .
まず再加熱温度を１１００〜１２５０℃の範囲に限定す
る。再加熱温度はＮｂ析出物を固溶させ、かつ圧延終了
温度を確保するために１１００℃以上としなければなら
ない。しかし再加熱温度が１２５０℃以上になると、γ
粒が著しく粗大化し、圧延によっても完全に微細化でき
ないため、優れた低温靭性が得られない。このため再加
熱温度を１２５０℃以下とする（望ましくは１１５０〜
１２００℃である）。First, the reheating temperature is limited to a range of 1100 to 1250°C. The reheating temperature must be 1100° C. or higher in order to dissolve Nb precipitates and ensure the rolling end temperature. However, when the reheating temperature exceeds 1250℃, γ
Since the grains become extremely coarse and cannot be completely refined even by rolling, excellent low-temperature toughness cannot be obtained. For this reason, the reheating temperature is set to 1250°C or lower (preferably 1150°C to 1150°C).
1200°C).
さらに９５０℃以下の累積圧下量を４０％以上、圧延終
了温度を７００〜８５０℃としなければならない。Further, the cumulative reduction amount below 950°C must be 40% or more, and the rolling end temperature must be 700 to 850°C.
これは再結晶域圧延で微細化したγ粒を低温圧延によっ
て延伸化し、フェライト粒径の徹底的な微細化をはかっ
て低温靭性を改善するためである。This is because the γ grains refined by recrystallization zone rolling are stretched by low-temperature rolling to thoroughly refine the ferrite grain size and improve low-temperature toughness.
累積圧下量が４０％未満ではγ組織の伸延化が不十分で
、微細なフェライト粒が得られない。If the cumulative reduction amount is less than 40%, the elongation of the γ structure is insufficient and fine ferrite grains cannot be obtained.
また圧延終了温度が８５０℃以上では、たとえ累積圧下
量が４０％以上でも微細なフェライト粒は達成できない
。しかし圧延終了温度が低下し過ぎると過度の（γ−α
）２相域圧延となり、低温靭性の劣化を招くので、圧延
終了温度の下限を７００℃とした。Furthermore, if the rolling end temperature is 850° C. or higher, fine ferrite grains cannot be achieved even if the cumulative reduction amount is 40% or higher. However, if the rolling end temperature decreases too much, excessive (γ−α
) The lower limit of the rolling end temperature was set at 700° C. since this resulted in rolling in a two-phase region and resulted in deterioration of low-temperature toughness.
圧延後の冷却条件は、空冷または加速冷却が望ましい。The cooling conditions after rolling are preferably air cooling or accelerated cooling.
加速冷却の条件としては圧延後、ただちに冷却速度１０
〜４０℃／ ｓｅｅで６００℃以下任意の温度まで冷却
、その後空冷することが望ましい。なおこの鋼を製造後
、焼戻、脱水素などの目的でＡ Ｃ１点以下の温度で再
加熱しても本発明の特徴を損なうものではない。The conditions for accelerated cooling are a cooling rate of 10 immediately after rolling.
It is desirable to cool down to any temperature below 600°C at ~40°C/see, and then air cool. Note that even if this steel is reheated at a temperature below the AC1 point for the purpose of tempering, dehydrogenation, etc. after manufacturing, the features of the present invention will not be impaired.
（実 施 例）
転炉一連続鋳造−厚板工程で種々の鋼成分の鋼板（厚み
１５〜３２ｍｍ）を製造し、その強度、靭性、低温靭性
および耐食性を調査した。(Example) Steel plates (thickness 15 to 32 mm) of various steel compositions were produced in a converter continuous casting-thick plate process, and their strength, toughness, low-temperature toughness, and corrosion resistance were investigated.
表１に実施例を示す。Examples are shown in Table 1.
本発明法にしたがって製造した鋼板（本発明鋼）はすべ
て良好な特性を有する。これに対して本発明によらない
比較鋼は、強度、低温靭性あるいは耐食性が劣る。All steel plates manufactured according to the method of the present invention (inventive steel) have good properties. In contrast, comparative steels not according to the present invention have inferior strength, low-temperature toughness, or corrosion resistance.
比較鋼１１−１９において、鋼１１はＣｒ量が低く、耐
食性が劣る。鋼■２はＣｒ量が多すぎるために、Ｐ が
高く溶接性が劣るほか、ＨＡＺ靭性も悪い。Among comparative steels 11-19, steel 11 has a low Cr content and poor corrosion resistance. Steel (2) has too much Cr, so it has high P and poor weldability, as well as poor HAZ toughness.
鋼１３はＣ量が高いために、母材とＨＡＺの低温靭性が
ともに劣る。鋼１４はＭｎ量が高いために、ＨＡＺ靭性
が劣る。鋼１５はＮｂを含有しないために、母材強度が
低く、靭性も悪い。鋼１６はＴｉを含有しないために母
材、ＨＡＺの靭性が悪い。鋼１７は再加熱温度が低いた
めに、母材の強度が十分でない。鋼１８は９５０℃以下
の累積圧下量が不足で、母材の靭性が悪い。また鋼１９
は圧延終了温度が低過ぎるために、母材の靭性が悪い。Since Steel 13 has a high C content, both the base metal and the HAZ have poor low-temperature toughness. Steel 14 has a high Mn content and therefore has poor HAZ toughness. Since Steel 15 does not contain Nb, its base material strength is low and its toughness is also poor. Since Steel 16 does not contain Ti, the base metal, HAZ, has poor toughness. Since steel 17 has a low reheating temperature, the strength of the base material is not sufficient. Steel 18 has an insufficient cumulative reduction of 950° C. or less, and the toughness of the base metal is poor. Also steel 19
The toughness of the base material is poor because the rolling end temperature is too low.
（発明の効果）
本発明により、低温靭性、現地溶接性の優れた耐ＣＯ２
腐食高強度ラインパイプの製造が可能となった。その結
果、現場での溶接施工能率やパイプラインの安全性が著
しく向上した。(Effects of the Invention) The present invention provides a CO2 resistant material with excellent low-temperature toughness and on-site weldability.
It has become possible to manufacture corroded high-strength line pipes. As a result, on-site welding efficiency and pipeline safety have significantly improved.
代 理 人teenager Reason Man
Claims (1)
＋（Ｎｉ＋Ｃｕ）／１５≦０．４８を満足する残部が鉄
および不可避的不純物からなる鋼を１１００℃〜１２５
０℃の温度範囲に加熱して、９５０℃以下の累積圧下量
４０％以上、圧延終了温度７００℃〜８５０℃で圧延を
行なった後、空冷または加速冷却することを特徴とする
高耐食性低合金ラインパイプ用鋼の製造法。 ２、重量％で Ｖ：０．０１〜０．０８、 Ｎｉ：０．０５〜０．５、 Ｃｕ：０．０５〜０．５、 Ｃａ：０．００１〜０．００５ を含有し、かつ０．３５≦Ｃ＋（Ｍｎ＋Ｃｒ＋Ｖ）／５
＋（Ｎｉ＋Ｃｕ）／１５≦０．４８を満足する残部が鉄
および不可避的不純物からなる鋼である請求項１記載の
高耐食性低合金ラインパイプ用鋼の製造法。[Claims] 1. In weight%, C: 0.02 to 0.09, Si: 0.5 or less, Mn: 0.7 to 1.5, P: 0.03 or less, S: 0.005 Below, Nb: 0.02 to 0.06, Cr: 0.5 to 1.2 or less, Ti: 0.005 to 0.03, Al: 0.05 or less, N: 0.002 to 0.005. Contains and 0.35≦C+(Mn+Cr+V)/5
+(Ni+Cu)/15≦0.48 and the balance consists of iron and inevitable impurities at 1100°C to 125°C
A high corrosion-resistant low alloy characterized by heating to a temperature range of 0°C, rolling at a cumulative reduction of 40% or more at 950°C or less and a rolling end temperature of 700°C to 850°C, and then air cooling or accelerated cooling. Method of manufacturing steel for line pipes. 2. Contains V: 0.01-0.08, Ni: 0.05-0.5, Cu: 0.05-0.5, Ca: 0.001-0.005 in weight%, and 0 .35≦C+(Mn+Cr+V)/5
2. The method for producing a highly corrosion-resistant, low-alloy line pipe steel according to claim 1, wherein the steel satisfies +(Ni+Cu)/15≦0.48 and the remainder consists of iron and unavoidable impurities.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005263A JP2711163B2 (en) | 1990-01-12 | 1990-01-12 | Method for producing high corrosion resistant low alloy linepipe steel with excellent corrosion resistance |
| CA002049050A CA2049050A1 (en) | 1990-01-12 | 1991-01-10 | Manufacturing method of high corrosion-resistant low-alloy steel for line pipes |
| DE4190090A DE4190090C2 (en) | 1990-01-12 | 1991-01-10 | Process for increasing the CO¶2¶ resistance by selecting the alloy composition of the steel and its use for line pipes |
| DE19914190090 DE4190090T (en) | 1990-01-12 | 1991-01-10 | |
| PCT/JP1991/000010 WO1991010752A1 (en) | 1990-01-12 | 1991-01-10 | Process for producing highly corrosion-resistant low-alloy steel for line pipe |
| GB9119268A GB2247246B (en) | 1990-01-12 | 1991-09-10 | Manufacturing method of high corrosion-resistant low-alloy steel for line pipes |
| NO913584A NO300552B1 (en) | 1990-01-12 | 1991-09-11 | Process for the manufacture of low alloy steel with high corrosion resistance for pipelines |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005263A JP2711163B2 (en) | 1990-01-12 | 1990-01-12 | Method for producing high corrosion resistant low alloy linepipe steel with excellent corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03211230A true JPH03211230A (en) | 1991-09-17 |
| JP2711163B2 JP2711163B2 (en) | 1998-02-10 |
Family
ID=11606343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005263A Expired - Lifetime JP2711163B2 (en) | 1990-01-12 | 1990-01-12 | Method for producing high corrosion resistant low alloy linepipe steel with excellent corrosion resistance |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JP2711163B2 (en) |
| CA (1) | CA2049050A1 (en) |
| DE (2) | DE4190090C2 (en) |
| GB (1) | GB2247246B (en) |
| NO (1) | NO300552B1 (en) |
| WO (1) | WO1991010752A1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5723089A (en) * | 1994-03-11 | 1998-03-03 | Nippon Steel Corporation | Line pipe metal arc welded with wire alloy |
| JP2011190506A (en) * | 2010-03-15 | 2011-09-29 | Nippon Steel Corp | Fire-resistant steel material superior in high-temperature strength of base metal and high-temperature ductility of weld heat-affected zone, and method for manufacturing the same |
| CN111118410A (en) * | 2020-01-16 | 2020-05-08 | 天津钢管制造有限公司 | Thick-wall large-caliber high-steel grade pipeline pipe with thickness of 40-60 mm and manufacturing method thereof |
| CN112695246A (en) * | 2020-12-08 | 2021-04-23 | 中国石油天然气集团有限公司 | Acid corrosion resistant high-strength pipeline steel and manufacturing method thereof |
| CN112921250A (en) * | 2021-01-25 | 2021-06-08 | 北京科技大学 | CO-resistant2Corroded steel pipe and preparation method thereof |
| CN112941422A (en) * | 2021-01-25 | 2021-06-11 | 北京科技大学 | CO-resistant2Steel plate for corrosion and preparation method thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9206422D0 (en) | 1992-03-24 | 1992-05-06 | Bolt Sarah L | Antibody preparation |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62112722A (en) * | 1985-11-13 | 1987-05-23 | Nippon Steel Corp | Production of steel sheet having excellent resistance to hydrogen induced cracking and resistance to sulfide stress corrosion cracking |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1084310A (en) * | 1976-04-12 | 1980-08-26 | Hiroaki Masui | High tension steel sheet product |
| JPS5814848B2 (en) * | 1979-03-30 | 1983-03-22 | 新日本製鐵株式会社 | Manufacturing method of non-tempered high-strength, high-toughness steel |
| JPS6338520A (en) * | 1986-08-01 | 1988-02-19 | Sumitomo Metal Ind Ltd | Production of steel plate having excellent hydrogen induced cracking resistance |
| DE3832014C2 (en) * | 1988-09-16 | 1994-11-24 | Mannesmann Ag | Process for the production of high-strength seamless steel tubes |
-
1990
- 1990-01-12 JP JP2005263A patent/JP2711163B2/en not_active Expired - Lifetime
-
1991
- 1991-01-10 DE DE4190090A patent/DE4190090C2/en not_active Expired - Lifetime
- 1991-01-10 CA CA002049050A patent/CA2049050A1/en not_active Abandoned
- 1991-01-10 WO PCT/JP1991/000010 patent/WO1991010752A1/en active Application Filing
- 1991-01-10 DE DE19914190090 patent/DE4190090T/de active Pending
- 1991-09-10 GB GB9119268A patent/GB2247246B/en not_active Expired - Lifetime
- 1991-09-11 NO NO913584A patent/NO300552B1/en not_active IP Right Cessation
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62112722A (en) * | 1985-11-13 | 1987-05-23 | Nippon Steel Corp | Production of steel sheet having excellent resistance to hydrogen induced cracking and resistance to sulfide stress corrosion cracking |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5723089A (en) * | 1994-03-11 | 1998-03-03 | Nippon Steel Corporation | Line pipe metal arc welded with wire alloy |
| JP2011190506A (en) * | 2010-03-15 | 2011-09-29 | Nippon Steel Corp | Fire-resistant steel material superior in high-temperature strength of base metal and high-temperature ductility of weld heat-affected zone, and method for manufacturing the same |
| CN111118410A (en) * | 2020-01-16 | 2020-05-08 | 天津钢管制造有限公司 | Thick-wall large-caliber high-steel grade pipeline pipe with thickness of 40-60 mm and manufacturing method thereof |
| CN112695246A (en) * | 2020-12-08 | 2021-04-23 | 中国石油天然气集团有限公司 | Acid corrosion resistant high-strength pipeline steel and manufacturing method thereof |
| CN112921250A (en) * | 2021-01-25 | 2021-06-08 | 北京科技大学 | CO-resistant2Corroded steel pipe and preparation method thereof |
| CN112941422A (en) * | 2021-01-25 | 2021-06-11 | 北京科技大学 | CO-resistant2Steel plate for corrosion and preparation method thereof |
| CN112921250B (en) * | 2021-01-25 | 2022-04-26 | 北京科技大学 | CO-resistant2Corroded steel pipe and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1991010752A1 (en) | 1991-07-25 |
| GB2247246A (en) | 1992-02-26 |
| GB2247246B (en) | 1994-05-11 |
| GB9119268D0 (en) | 1991-11-20 |
| DE4190090C2 (en) | 1996-09-05 |
| CA2049050A1 (en) | 1991-07-13 |
| JP2711163B2 (en) | 1998-02-10 |
| NO913584D0 (en) | 1991-09-11 |
| NO913584L (en) | 1991-09-11 |
| NO300552B1 (en) | 1997-06-16 |
| DE4190090T (en) | 1992-01-30 |
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