JPS5844726B2 - Method for manufacturing high-strength ERW steel pipes for oil wells with excellent hydrogen embrittlement resistance - Google Patents
Method for manufacturing high-strength ERW steel pipes for oil wells with excellent hydrogen embrittlement resistanceInfo
- Publication number
- JPS5844726B2 JPS5844726B2 JP10792679A JP10792679A JPS5844726B2 JP S5844726 B2 JPS5844726 B2 JP S5844726B2 JP 10792679 A JP10792679 A JP 10792679A JP 10792679 A JP10792679 A JP 10792679A JP S5844726 B2 JPS5844726 B2 JP S5844726B2
- Authority
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- Prior art keywords
- steel
- hydrogen embrittlement
- concentration
- embrittlement resistance
- steel pipes
- 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
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Classifications
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Description
【発明の詳細な説明】
本発明は主としてサワー油井用鋼管として使用される耐
水素脆性の優れた強度水準がAPI規格のN−80クラ
ス以上である油井用高張力電縫鋼管の製造方法に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing high-strength electric resistance welded steel pipes for oil wells, which are mainly used as steel pipes for sour oil wells and have excellent hydrogen embrittlement resistance and a strength level of API standard N-80 class or higher. It is.
従来多量の硫化水素を含有する石油あるいは天然ガスを
採取する油井あるいはガス井(すなわちいわゆるサワー
油井、サワーガス井、以下サワー油井と略称する。Conventionally, oil or gas wells (i.e., sour oil wells, sour gas wells, hereinafter abbreviated as sour oil wells) are used to extract oil or natural gas containing a large amount of hydrogen sulfide.
)におけるケーシングやチュービングには、特にきびし
いサワーの場合、低合金鋼あるいは特殊合金により製造
された耐水素脆性を有するシームレス鋼管が使用されて
いる。) Seamless steel pipes made of low-alloy steel or special alloys and resistant to hydrogen embrittlement are used for the casings and tubing in the sour systems.
電縫鋼管の場合は、一部の地域において(おそらくあま
りきびしくないサワー油井に使用されていると考えられ
る。In the case of ERW steel pipe, it is thought that it is used in some areas (probably in less severe sour oil wells).
)かたさ規制を実施したサワー油井用鋼管の使用が知ら
れているのみである。) The only known use is steel pipe for sour oil wells with stiffness regulations.
本発明でいう耐水素脆性とは、近年型として石油、天然
ガスのラインパイプで問題となっている耐水素誘起割れ
とは異なり、従来からH2Sを含む環境における鋼材の
硫化物応力腐食割れとして知られているものであって、
耐水素誘起割れと明確に区別するために、耐水素脆性と
称するものである。Hydrogen embrittlement in the present invention refers to sulfide stress corrosion cracking, which has been known as sulfide stress corrosion cracking of steel materials in environments containing H2S, unlike hydrogen-induced cracking, which has become a problem in oil and natural gas line pipes in recent years. It is something that is
This is referred to as hydrogen embrittlement resistance to clearly distinguish it from hydrogen-induced cracking resistance.
この区別は、たとえば特開昭50−97517号公報に
も明確に述べられている。This distinction is also clearly stated in, for example, Japanese Patent Laid-Open No. 50-97517.
ここで硫化物応力腐食割れ(本発明でいう水素脆性)に
関する従来の知見を概説する。Here, conventional knowledge regarding sulfide stress corrosion cracking (hydrogen embrittlement in the present invention) will be summarized.
これはたとえば鉄と鋼第54年(1968)第5号R6
10に「高張力鋼の硫化物腐食割れ」に関する解説があ
り、要旨の一部は以下の通りである。This is, for example, Tetsu to Hagane No. 54 (1968) No. 5 R6
10 contains an explanation regarding ``sulfide corrosion cracking in high-strength steel,'' and part of the gist is as follows.
「割れは、硫化物応力腐食割れあるいは水素脆性割れと
して1940年頃から知られている。"Cracking has been known since about 1940 as sulfide stress corrosion cracking or hydrogen embrittlement cracking.
H2Sを含む腐食環境および鋼材に応力が存在する条件
下において脆性破面を呈する破壊である。This is a fracture that exhibits a brittle fracture surface in a corrosive environment containing H2S and under conditions where stress is present in the steel material.
鋼材の強度水準が上昇すると割れ感受性が増加すること
が知られている。It is known that as the strength level of steel increases, its susceptibility to cracking increases.
APIN−80クラスの強度を有する油井用鋼管(本発
明者らは、これらは全てシームレス鋼管に関するもので
あると推定している)の硫化物応力腐食割れにおよぼす
合金元素の影響として知られていることは、■Mn量が
1.65%以上は有害である■Niは有害である■Cr
+ Tt +Vr Bの添カロは割れ防止に有効であ
る等の知見である。It is known that the influence of alloying elements on sulfide stress corrosion cracking of oil well steel pipes (we estimate that all of these relate to seamless steel pipes) having APIN-80 class strength is known. This means that ■ Mn content of 1.65% or more is harmful ■ Ni is harmful ■ Cr
It is known that the addition of +Tt +Vr B is effective in preventing cracking.
またこの場合の金属組織の影響については種々の説があ
るが、一般的には、焼入焼もどし組織が焼熱組織より良
いと言われている。Although there are various theories regarding the influence of the metal structure in this case, it is generally said that the quenched and tempered structure is better than the sintered structure.
」さらに、焼入・焼もどし鋼材の耐水素脆性に関しては
、従来の知見ではかたさが影響し、かたさが低いほど割
れにくいとされている。Furthermore, conventional knowledge suggests that the hydrogen embrittlement resistance of hardened and tempered steel is affected by hardness, and the lower the hardness, the more difficult it is to break.
(T、M。Swanson and J 、P 、Tr
almer : MaterialsProtecti
on &Performance、 Vol、 11
。(T., M. Swanson and J., P., Tr.
almer: MaterialsProtecti
on & Performance, Vol. 11
.
Jan、(1972)P、36〜38)
以上の知見はシームレス鋼管について得られたものであ
り、本発明のように溶接部を有する電縫鋼管に関するも
のではない。Jan, (1972) P, 36-38) The above findings were obtained regarding seamless steel pipes, and do not relate to electric resistance welded steel pipes having welded portions as in the present invention.
本発明に関連のある従来技術としては、本発明者らによ
る「高張力電縫鋼管の製造方法」(特願昭50−783
77号および特願昭50−91232号)がある。As a prior art related to the present invention, "Method for manufacturing high-tensile resistance-welded steel pipes" by the present inventors (Japanese Patent Application No. 50-783)
No. 77 and Japanese Patent Application No. 50-91232).
それらの要旨は以下のようである。まず特願昭50−7
8377号は、C:O,15〜0.30%t Mn≦1
.5%、Si<0.5%、P≦0.03%、S≦0.0
3%+’l’i≦0.03%、B:0.0003〜0.
0025%、N≦o、ooso%、脱酸度を調整するこ
とにより残存するsol、A7゜残部Feおよび不可避
的不純物よりなる素材鋼板を用い電縫溶接により電縫鋼
管とした後、該鋼管に焼入・焼もどし処理を施すことに
より引張強さ65kg/rm!以上の高張力電縫鋼管を
製造する方法である。Their summary is as follows. First, the special request was made in 1977.
No. 8377 is C:O, 15-0.30%t Mn≦1
.. 5%, Si<0.5%, P≦0.03%, S≦0.0
3%+'l'i≦0.03%, B: 0.0003-0.
0025%, N≦o, ooso%, remaining sol by adjusting the degree of deoxidation, A7゜ balance Fe and unavoidable impurities are used to make an ERW steel pipe by ERW welding, and then the steel pipe is sintered. Tensile strength is 65kg/rm by applying heating and tempering treatment! This is a method of manufacturing the above-described high-tensile resistance welded steel pipe.
また特願昭50−91232号は、C:0.06〜0.
25%+□Mn≦1.5%、Si<0.5%、P<0.
03%、S≦0.03%、Ti≦0.03%、B:00
OOO3〜0.0025%、 N<0.0080%、成
分に加えて、Ni≦1.0%+Cr≦1.o%。Furthermore, Japanese Patent Application No. 1983-91232 has C: 0.06 to 0.
25%+□Mn≦1.5%, Si<0.5%, P<0.
03%, S≦0.03%, Ti≦0.03%, B:00
OOO3~0.0025%, N<0.0080%, in addition to the components, Ni≦1.0%+Cr≦1. o%.
Mo≦0.8%、■≦0.2%、Nb≦0.2%の1種
または2種以上を成分とし、脱酸度を調整することによ
り残存するs o l 、 Al、残部Feおよび不可
避的不純物よりなる素材鋼板を用い電縫溶接により電縫
鋼管とした後、該鋼管に焼入・焼もどし処理を施すこと
により引張強さ75 kg/ym1以上の高張力電縫鋼
管を製造する方法である。One or more of Mo≦0.8%, ■≦0.2%, Nb≦0.2% is used as a component, and by adjusting the degree of deoxidation, remaining sol, Al, remaining Fe and unavoidable A method for manufacturing a high-tensile resistance welded steel pipe with a tensile strength of 75 kg/ym1 or more by using a steel plate made of material containing impurities and making it into an resistance welded steel pipe by electric resistance welding, and then subjecting the steel pipe to quenching and tempering treatment. It is.
以上2件の発明は、「高張力電縫鋼管の製造方法」に関
するもので、耐水素脆性は考慮していない。The above two inventions relate to a "method for manufacturing high-tensile resistance welded steel pipes" and do not take into account hydrogen embrittlement resistance.
本発明は電縫鋼管の耐水素脆性の改善研究を鋭意実施し
て得られた結果にもとづくものであり、耐水素脆性の優
れた高張力電縫鋼管およびその製造方法に関するもので
あって、その骨子とするところは、重量濃度で、C:0
.06〜0.35%。The present invention is based on the results obtained through intensive research on improving the hydrogen embrittlement resistance of ERW steel pipes, and relates to a high-tensile ERW steel pipe with excellent hydrogen embrittlement resistance and a method for manufacturing the same. The main point is the weight concentration, C: 0
.. 06-0.35%.
Si<0.50%、 Mn < 1.6%、P≦0.0
40%。Si<0.50%, Mn<1.6%, P≦0.0
40%.
S≦0.010%、Ti≦0.040%、B:0.00
01〜0.0025%、N≦o、ooso%、Cu:0
.25〜0.40%、Al≦0.1%を含有し、かつT
iおよびNについては鋼中N濃度が0.0055%以上
o、ooso%以下である場合には0.040%≧〔%
Ti )≧3,42X(%N)+0.0022%を満
足し、鋼中N濃度がQ、0035%以上で0.0055
%未満である場合には0.040%≧〔%Ti〕≧10
.5X(%N、l−0.0368%を満足し、鋼中N濃
度が0.0035%未満である場合には0.040%≧
〔%Ti 〕≧o、ooo%を満足し、さらにCa :
0.001〜0.1%+ REM(Rare Ear
thMetals ) : 0.005〜0.1%の1
種または2種を含有し、かつ重量(濃度)比でCa /
S≧0.5゜REM/S≧1.0となした残部は実質
的にFeより成る鋼材を用いて電縫鋼管を製造して、該
電縫鋼管をその化学組成によって決まるオーステナイト
化温度以上かつ1100℃以下の温度に770熱後焼入
し、500℃以上Ac3以下の温度で焼もどしを実施し
た耐水素脆性の優れた引張強さ65kg/m4以上を有
する油井用高張力電縫鋼管の製造方法である。S≦0.010%, Ti≦0.040%, B: 0.00
01-0.0025%, N≦o, ooso%, Cu:0
.. 25-0.40%, Al≦0.1%, and T
Regarding i and N, if the N concentration in the steel is 0.0055% or more and ooso% or less, 0.040%≧[%
Ti) ≧3,42
If it is less than %, 0.040%≧[%Ti]≧10
.. 5
[%Ti]≧o, ooo% is satisfied, and Ca:
0.001~0.1%+ REM (Rare Ear
thMetals): 0.005-0.1% 1
or two species, and the weight (concentration) ratio is Ca/
S≧0.5゜REM/S≧1.0, and the remaining part is substantially made of Fe to produce an ERW steel pipe, and the ERW steel pipe is heated to a temperature higher than the austenitizing temperature determined by its chemical composition. A high tensile resistance welded steel pipe for oil wells having excellent hydrogen embrittlement resistance and a tensile strength of 65 kg/m4 or more, which is quenched at a temperature of 1100°C or lower for 770 degrees and tempered at a temperature of 500°C or higher and Ac3 or lower. This is the manufacturing method.
以下に本発明について詳細に説明する。The present invention will be explained in detail below.
まず本発明者らは種々の研究の結果、Bを含む焼入・焼
もとし電縫鋼管に関して電縫溶接ボンド部(以下ボンド
部と略称する)の焼入性を改善して母材部並とすること
に成功した。First, as a result of various studies, the present inventors have found that the hardenability of the ERW welded bond part (hereinafter abbreviated as "bond part") of quenched and tempered ERW steel pipes containing B can be improved to achieve the same level as that of the base material. succeeded in doing so.
すなわち焼入性を確保するためには周知のごとく鋼中に
固溶Bが存在することが必要であり、そもそも本発明に
かかわる成分糸を有する鋼に関しては、充分な焼入性を
保有させるために必要な固溶B量を確保する目的でTi
を添加しており、鋼中のNをすべてTiNとして析出さ
せこれによってBN析出による固溶B量の減少を防止し
ているものである。In other words, in order to ensure hardenability, it is necessary for solid solution B to exist in steel, and in the first place, in order to ensure sufficient hardenability for steel having the component threads related to the present invention, it is necessary to have solid solution B in steel. In order to secure the amount of solid solution B required for
All of the N in the steel is precipitated as TiN, thereby preventing a decrease in the amount of solid solution B due to BN precipitation.
しかし従来電縫鋼管のボンド部については、電縫溶接時
の脱炭反応および酸化反応によって鋼中C濃度および鋼
中Ti濃度の低下現象が発生しており、ボンド部焼入性
は母材部のそれに比較して大幅に低いという実情であっ
た。However, in the bond part of conventional ERW steel pipes, the decarburization reaction and oxidation reaction during ERW welding cause a decrease in C concentration and Ti concentration in the steel, and the hardenability of the bond part is lower than that of the base metal. The actual situation was that it was significantly lower than that of .
本発明者らはこの欠点を補うため種々の研究を実施した
結果、鋼中のTi濃度およびN濃度を規制することによ
ってボンド部焼入性を確保することが可能であることを
見出して、かつそれらの適正な鋼中組成範囲として以下
の結果を得た。As a result of conducting various studies to compensate for this drawback, the present inventors discovered that it is possible to ensure bond hardenability by regulating the Ti and N concentrations in the steel, and The following results were obtained as the appropriate steel composition range.
すなわち■鋼中N濃度が0.0055%以上でo、oo
so%以下である場合には0.040%〔%Ti )≧
3,42X(%N)+0.0022%を満足し、(但し
0は0内の元素の鋼中重量濃度を示す。That is, ■ o, oo when the N concentration in steel is 0.0055% or more.
If it is less than so%, 0.040% [%Ti)≧
3,42X(%N)+0.0022% (where 0 indicates the weight concentration of the element within 0 in the steel).
以下間)、■鋼中N濃度が0.0035%以上で0.0
055%未満である場合には、0.040%≧〔%Ti
)≧10.5X(%N)−0,0368%を満足し、
■鋼中N濃度が0.0035%未満である場合には0.
040%≧〔%Ti 〕≧o、ooo%を満足するもの
であり、その範囲を図に示すと第1図の如く鋼中添加元
素の化学組成範囲を第1図に示す領域内とすることによ
って、ボンド部と母材部との品質の差異が非常に少なく
なり、その結果ボンド部の腐食抑制に大きく貢献し耐水
素脆性がいちじるしく改善されることを見出したもので
ある。(below), ■ 0.0 when the N concentration in steel is 0.0035% or more
If it is less than 0.055%, 0.040%≧[%Ti
)≧10.5X(%N)-0,0368%,
■0.0 if the N concentration in the steel is less than 0.0035%.
040%≧[%Ti]≧o, ooo%, and the range is shown in the diagram as shown in Figure 1.The chemical composition range of the added elements in the steel should be within the range shown in Figure 1. It has been found that the difference in quality between the bond part and the base metal part is greatly reduced, and as a result, it greatly contributes to suppressing corrosion of the bond part and significantly improves hydrogen embrittlement resistance.
さらに加えてCa: 0.001〜O11%、REM:
0.005〜Q、1%の1種または2種を含有し、かつ
重量比でCa / S2O,5、REM/S≧1.0と
なすことにより、電縫鋼管特有の溶接時に発生する溶接
部近傍のメタルフローに添った介在物の先端の尖鋭化を
防止して、溶接ボンド部の耐水素脆性が非常に優れてお
り、母材部分のそれとほとんど同水準であることを特徴
とする耐水素脆性の優れた油井用高張力電縫鋼管の製造
に成功したものである。Additionally, Ca: 0.001-11%, REM:
By containing one or two types of 0.005~Q, 1%, and setting the weight ratio of Ca/S2O,5, REM/S≧1.0, welding that occurs during welding that is unique to ERW steel pipes. The weld bond has excellent hydrogen embrittlement resistance, which is almost at the same level as that of the base metal, by preventing the sharpening of the tip of inclusions that follow the metal flow near the weld bond. We have succeeded in manufacturing high-tensile resistance welded steel pipes for oil wells with excellent hydrogen embrittlement.
従来よりサワー油井に使用されているシームレス鋼管は
、一般に電縫鋼管に比較して高価であって本発明法によ
って安価な電縫鋼管を使用し得ることは、工業的貢献が
非常に太きいものである。Seamless steel pipes conventionally used in sour oil wells are generally more expensive than ERW steel pipes, and the ability to use inexpensive ERW steel pipes by the method of the present invention is a significant industrial contribution. It is.
次に本発明における各成分組成および熱処理温度の限定
理由について説明する。Next, the reason for limiting the composition of each component and the heat treatment temperature in the present invention will be explained.
Cは他の合金元素とともに鋼材の強度を確保するのに必
要な元素で、0.06未満では必要な強度が得られない
ことおよび溶接部欠陥が発生するため、0.06%以上
とした。C is an element necessary to ensure the strength of the steel material together with other alloying elements, and if it is less than 0.06, the necessary strength cannot be obtained and weld defects will occur, so it is set to 0.06% or more.
またC濃度が0.35%を超えると溶接性ならびに加工
性が劣化する。Furthermore, if the C concentration exceeds 0.35%, weldability and workability deteriorate.
従ってC濃度は0.06〜0.35%とする。Therefore, the C concentration is set to 0.06 to 0.35%.
MnおよびSiは溶接部の健全性を維持するうえで重要
な元素でありまた強度を確保するうえでも重要である。Mn and Si are important elements for maintaining the integrity of the welded joint, and are also important for ensuring strength.
Mnは溶接性の点から1,60%を上限とする。The upper limit of Mn is 1.60% from the viewpoint of weldability.
Siは溶接性およびカロエ性が劣化するので0.50%
を上限とする。Si is 0.50% because it deteriorates weldability and heat resistance.
is the upper limit.
Mn / S iは溶接欠陥防止の観点から3〜10程
度であることが望ましい。Mn/Si is desirably about 3 to 10 from the viewpoint of preventing welding defects.
また耐水素脆性の観点から、Mn濃度は低い方が望まし
く特に0.5%以下において優れた性質を示す。In addition, from the viewpoint of hydrogen embrittlement resistance, it is desirable that the Mn concentration is low, and exhibits excellent properties particularly when it is 0.5% or less.
この場合Si濃度は特に厳重な管理を実施して、MrL
/siを確実に3〜10となし溶接欠陥発生を防止する
必要がある。In this case, the Si concentration must be particularly strictly controlled, and MrL
It is necessary to ensure that /si is 3 to 10 to prevent welding defects.
P、Sについては周知のごとく靭性および延性を著しく
損なう元素であり少量であるほど望ましいものであるが
、耐水素脆性の観点からはSが特に有害であり上限を0
.010°Cとする。As is well known, P and S are elements that significantly impair toughness and ductility, and the smaller the amount, the better. However, from the perspective of hydrogen embrittlement resistance, S is particularly harmful, and the upper limit should be set at 0.
.. 010°C.
Pは0.040%を上限とする。The upper limit of P is 0.040%.
Bは鋼の焼入性向上を目的として添加する元素で0.0
001%未満では焼入性向上効果が期待できず、また0
、0025%以上では表面疵発生および靭性劣化の原因
となる。B is an element added for the purpose of improving the hardenability of steel and is 0.0
If it is less than 0.001%, no improvement in hardenability can be expected;
,0025% or more causes surface flaws and toughness deterioration.
従ってB濃度は0.0001〜0.0025%とする。Therefore, the B concentration is set to 0.0001 to 0.0025%.
このBの焼入性向上効果はNの存在によって損なわれる
ためNをTiNとして固定化する目的でTiを添加する
。Since the hardenability improving effect of B is impaired by the presence of N, Ti is added for the purpose of fixing N as TiN.
添力目するTi濃度は0.04%を超えると鋼材表面疵
の発生および被削性の低下等の品質上の欠点が生ずる。If the Ti concentration as an additive exceeds 0.04%, quality defects such as occurrence of surface flaws on the steel material and reduction in machinability will occur.
従ってTi濃度は0.04%以下とする。Therefore, the Ti concentration is set to 0.04% or less.
Nは最低限にみつもっても通常0.0010−0.00
20%程度は不可避的に存在し、また特に添770を行
なわなくてもo、ooso%程度まで存在することもあ
る。N is usually 0.0010-0.00 even if you keep it at a minimum.
About 20% is unavoidably present, and even without special addition 770, it may be present up to about o, ooso%.
特に添カロしないという意味でN濃度の上限をo、oo
so%とするが、N濃度は少なければ少ない程焼入性向
上の観点から望ましい。In particular, the upper limit of the N concentration is o, oo in the sense of not adding calories.
So%, but the lower the N concentration, the more desirable it is from the viewpoint of improving hardenability.
従って物理的に不可能ではあるがOppmであれば最も
望ましい状態である。Therefore, although it is physically impossible, Oppm is the most desirable state.
TiとN濃度については、ポンド部焼入性を確保するた
めに、第1図の組成範囲であることが必要であることは
先に詳述した通りである。As described in detail above, the Ti and N concentrations need to be within the composition range shown in FIG. 1 in order to ensure hardenability of the pound part.
Cuは腐食抑制の効果と耐水素脆性向上効果を得るため
に少くとも0,25%以上を必要とする。Cu needs to be at least 0.25% to obtain the effect of inhibiting corrosion and improving hydrogen embrittlement resistance.
また電縫溶接性の点で0.40%を超えると難点が生じ
、溶接困難となる。Moreover, in terms of electric resistance weldability, if it exceeds 0.40%, difficulties arise and welding becomes difficult.
従ってCu濃度は0.25〜0.40%とする。Therefore, the Cu concentration is set to 0.25 to 0.40%.
A7は0.1%以上では鋼の品質が劣化する。If A7 exceeds 0.1%, the quality of the steel will deteriorate.
REMおよびCaは電縫溶接時のボンド部近傍のメタル
フローにそった介在物の尖鋭化防止を目的としており、
この目的を遠戚するために必要な最低濃度は、REMは
0.005%、Caは0.001%である。REM and Ca are intended to prevent inclusions along the metal flow near the bond part during electric resistance welding from becoming sharp.
The minimum concentrations required to achieve this objective are 0.005% for REM and 0.001% for Ca.
またREMは0.1%、Caも0,1%を超えて添加し
てもその効果の増大は得られず、かえって添加技術等製
造上の困難が増大する。Further, even if REM is added in an amount exceeding 0.1% and Ca is added in an amount exceeding 0.1%, no increase in the effect is obtained, and on the contrary, difficulties in manufacturing such as addition techniques increase.
また前記尖鋭化防止の目的を満たすためにはREM/S
≧1.0.Ca/S≧0.5であることが必要である。In addition, in order to meet the purpose of preventing sharpening, REM/S
≧1.0. It is necessary that Ca/S≧0.5.
REMおよびCa、またこれ以外の元素もすべて鋼管に
要求される靭性、延性あるいは強度に応じて適宜組合せ
て添カ目するものであるこというまでもない。It goes without saying that REM, Ca, and other elements may be added in appropriate combinations depending on the toughness, ductility, or strength required of the steel pipe.
該電縫鋼管の焼入に際して加熱温度を、その化学組成に
よって決まるオーステナイト化温度以上とする理由は、
焼入にはオーステナイトよりの急冷が必要不可欠である
ためである。The reason why the heating temperature during quenching of the electric resistance welded steel pipe is set to be higher than the austenitizing temperature determined by its chemical composition is as follows.
This is because rapid cooling from austenite is essential for quenching.
また同力日熱温度を1100℃以下とする理由はオース
テナイト結晶粒の粗大化を防止し、結晶粒粗大化による
耐水素脆性の低下を防止するためである。The reason why the isotropic solar temperature is set to 1100° C. or lower is to prevent coarsening of austenite crystal grains and prevent deterioration of hydrogen embrittlement resistance due to coarsening of crystal grains.
また該電縫鋼管の焼もどし温度を500°C以上とする
理由は、500′C未満では鋼の焼もどしが不充分で耐
水素脆性が低く、500℃以上ではじめて充分な耐水素
脆性となるためである。The reason why the tempering temperature of the ERW steel pipe is set to 500°C or higher is that below 500°C, the steel is insufficiently tempered and its hydrogen embrittlement resistance is low, and sufficient hydrogen embrittlement resistance is achieved only at temperatures above 500°C. It's for a reason.
焼もどし温度をAc 3以下とする理由は、AC3以上
では、鋼の組織が変化して耐水素脆性が低下するためで
ある。The reason why the tempering temperature is set to Ac 3 or lower is that at AC 3 or higher, the structure of the steel changes and the hydrogen embrittlement resistance decreases.
ここで実施例による本発明の詳細な説明するのに先立ち
、耐水素脆性試験について概説する。Here, prior to a detailed explanation of the present invention based on examples, a hydrogen embrittlement test will be outlined.
鋼の耐水素脆性を評価する試験方法は、たとえばDCB
試験・定荷重引張試験・3点曲げ試験・4点曲げ試験な
ど種々の方法が知られているが、鋼管特に溶接鋼管の溶
接部評価を目的とする場合は、CIJソング験が最適と
考える。The test method for evaluating the hydrogen embrittlement resistance of steel is, for example, DCB.
Various methods are known, such as testing, constant load tensile testing, 3-point bending tests, and 4-point bending tests, but when the purpose is to evaluate the welds of steel pipes, especially welded steel pipes, the CIJ song test is considered to be optimal.
CIJソング験は、鋼管より外力、変形を与えずに管形
状のままの試験片を切り出して、鋼管の使用中の状態に
近い応力状態で試験を行ないうるという特徴を有する。The CIJ song test has the feature that a test piece can be cut out from a steel pipe in its original shape without applying any external force or deformation, and the test can be conducted under stress conditions close to the state in which the steel pipe is in use.
CIJソング験についても、細部が異った種々の試験方
法が知られているが、本発明者らは、表1、第2図に示
した試験方法が最も広く一般的に実施されていると考え
て、この試験方法によって鋼管の母材部および溶接部の
耐水素脆性評価を実施した0
この試験方法は、比較的大きな応力を付カロして腐食環
境下に置いたC IJソング験片について、割れ発生ま
での時間を測定するものである。Regarding the CIJ song test, various test methods with different details are known, but the present inventors believe that the test method shown in Table 1 and Figure 2 is the most widely and commonly practiced. This test method was used to evaluate the hydrogen embrittlement resistance of the base metal and welded parts of steel pipes. , which measures the time until cracking occurs.
次に鋼管の耐水素脆性に関する一般的説明を行ない、ひ
きつづいて本発明の実施例を示して、本発明の詳細な説
明する。Next, a general explanation regarding the hydrogen embrittlement resistance of steel pipes will be given, followed by a detailed explanation of the present invention by showing examples of the present invention.
シームレス鋼管の耐水素脆性については、従来から種々
の研究かなされており前述のごとく多くの知見が得られ
ている。Various studies have been conducted on the hydrogen embrittlement resistance of seamless steel pipes, and as mentioned above, much knowledge has been obtained.
しかし高張力電縫鋼管の耐水素脆性の水準は、いまだ一
般的に明らかにされてはいないと考える。However, we believe that the level of hydrogen embrittlement resistance of high-strength ERW steel pipes has not yet been generally clarified.
本発明者らは、一般的な高張力電縫鋼管の耐水素脆性の
水準を明らかにするために、従来知られている高張力電
縫鋼管について上記のCIJソング験(以下単にCリン
グ試験と称する)を実施した。In order to clarify the level of hydrogen embrittlement resistance of general high-tensile resistance welded steel pipes, the present inventors conducted the above-mentioned CIJ song test (hereinafter simply referred to as the C-ring test) on conventionally known high-tensile resistance welded steel pipes. ) was carried out.
その結果が表2〜表4の比較例1,2.3である。The results are Comparative Examples 1 and 2.3 in Tables 2 to 4.
これらより明らかなごとく、高張力電縫鋼管の耐水素脆
性は、(1)降伏点が高いほど割れ発生までの時間が短
くなり、その変化の割合は比較的大きい。As is clear from the above, the hydrogen embrittlement resistance of high-strength electric resistance welded steel pipes is as follows: (1) The higher the yield point, the shorter the time until cracking occurs, and the rate of change is relatively large.
(2)母材部に比較して溶接部(電縫溶接ボンド部)の
耐水素脆性は大幅に劣っており、割れ発生までの時間が
母材部のそれの172以下である。(2) The hydrogen embrittlement resistance of the welded part (ERW weld bond part) is significantly inferior to that of the base metal part, and the time until cracking occurs is 172 times shorter than that of the base metal part.
という特徴を有する。It has the following characteristics.
なお比較例3は、鋼中Mn濃度が約0.5%という低い
水準の材料であり、比較的良好な耐水素脆性特性を有す
るものである。Note that Comparative Example 3 is a material with a low Mn concentration of about 0.5% in steel, and has relatively good hydrogen embrittlement resistance.
次に、本発明の実施例を表2〜表4に示す。Next, Examples of the present invention are shown in Tables 2 to 4.
実施例1は鋼中C濃度が0.12%と比較的低いもので
、誘導加熱焼入・誘導力ロ熱焼もどしを実施した降伏点
が63.8kg/miの鋼管である。Example 1 is a steel pipe in which the C concentration in the steel is relatively low at 0.12%, and the yield point is 63.8 kg/mi after induction quenching and induction heat tempering.
本発明の基本的な構成要件である■Ti、N濃度が第1
図に示す領域に含まれること■CaあるいはREMを所
定量含有すること■Cuを所定量含有することの3項目
をすべて満足しないでかつ実施例1とほぼ同一条件で製
造されかつ同一水準の降伏点を有する比較材は比較例1
であり、これら両者のCIJソング験結果を比較すれば
、実施例1では母材部、溶接部とも耐水素脆性が大幅に
改善されていることが明らかである。■Ti and N concentrations, which are the basic constituents of the present invention, are the first
Included in the region shown in the figure; ■ Contain a predetermined amount of Ca or REM; ■ Contain a predetermined amount of Cu. Manufactured under almost the same conditions as Example 1 and with the same level of yield. Comparative material with points is Comparative Example 1
Comparing the CIJ song test results for both, it is clear that in Example 1, the hydrogen embrittlement resistance of both the base metal part and the welded part is greatly improved.
実施例2は鋼中C濃度が0.25%のものであり、実施
例3は鋼中C濃度が0.24%、鋼中Mn濃度が0.5
3%のものである。Example 2 has a steel C concentration of 0.25%, and Example 3 has a steel C concentration of 0.24% and a steel Mn concentration of 0.5.
3%.
実施例3より鋼中Mn濃度が低い場合、きわめて優れた
耐水素脆性を有する高張力電縫鋼管が得られることが明
らかである。It is clear from Example 3 that when the Mn concentration in the steel is low, a high-tensile resistance welded steel pipe having extremely excellent hydrogen embrittlement resistance can be obtained.
実施例2および3と対比される類似の化学組成、製造方
法を有する本発明を外れた比較例はそれぞれ比較例2お
よび3である。Comparative examples other than the present invention having similar chemical compositions and manufacturing methods to those of Examples 2 and 3 are Comparative Examples 2 and 3, respectively.
実施例4は鋼中C濃度が0.33%の例である。Example 4 is an example in which the C concentration in the steel is 0.33%.
また上記の本発明の基本的な構成要件3項目の1部を満
足し1部が外れた場合の例を比較例4および5に示す。Further, Comparative Examples 4 and 5 show examples in which one part of the three basic constituent requirements of the present invention was satisfied but one part was not satisfied.
以上の実施例および比較例より本発明の効果は明白であ
り、本発明の工業的貢献は非常に大きなものである。The effects of the present invention are clear from the above Examples and Comparative Examples, and the industrial contribution of the present invention is very large.
【図面の簡単な説明】
第1図は本発明のボンド部焼入性を確保し良好な耐水素
脆性特性を得るために必要な鋼中のTiおよびN濃度の
範囲を示す説明図、第2図はCIJソング験片の説明図
である。[Brief Description of the Drawings] Figure 1 is an explanatory diagram showing the range of Ti and N concentrations in the steel necessary to ensure the hardenability of the bond part of the present invention and obtain good hydrogen embrittlement resistance. The figure is an explanatory diagram of a CIJ song specimen.
Claims (1)
≦0.50%+ Mn :≦1.6%、P≦0.040
%、S≦0.010%、 Ti<:0.040%、B:
0.0001〜0.0025%、 N<0.0080%
、Cu:0.25〜0.40%、A7≦0.1%を含有
し、かつTiおよびNについては鋼中N濃度が0.00
55%以上でo、ooso%以下である場合には0.0
40%≧〔%Ti )≧3.42X(%N)+0.00
22%を満足し、鋼中N濃度が0.0035%以上で0
.0055%未満である場合には0.040%≧〔%T
i〕≧10.5X(%N)−0,0368%を満足し、
鋼中N濃度が0.0035%未満である場合には0.0
40%≧〔%Ti )≧o、ooo%を満足し、さら
にCa二0.001〜0.1%、 REM(Rare
Earth Met−als ) : 0.005〜0
.1%の1種または2種を含有し、かつ重量(濃度)比
でCa / S≧0.5゜REM/S≧1.0となした
残部は実質的にFeより成る鋼材を用いて電縫鋼管を製
造して、該電縫鋼管をその化学組成によって決まるオー
ステナイト化温度以上かつ1100℃以下の温度に加熱
後焼入し、500℃以上AC3以下の温度で焼もどしを
実施した耐水素脆性の優れた引張強さ65kg/mA以
上を有する油井用高張力電縫鋼管の製造方法。[Claims] 1. C: 0.06 to 0.35%ysjt in terms of weight concentration
≦0.50%+Mn:≦1.6%, P≦0.040
%, S≦0.010%, Ti<:0.040%, B:
0.0001-0.0025%, N<0.0080%
, Cu: 0.25-0.40%, A7≦0.1%, and the N concentration in the steel is 0.00 for Ti and N.
o if 55% or more, 0.0 if ooso% or less
40%≧[%Ti)≧3.42X(%N)+0.00
22% and the N concentration in the steel is 0.0035% or more.
.. If it is less than 0.055%, 0.040%≧[%T
i]≧10.5X(%N)-0,0368%,
0.0 if the N concentration in steel is less than 0.0035%
40%≧[%Ti)≧o,ooo%, and further Ca20.001~0.1%, REM (Rare
Earth Met-als): 0.005~0
.. The remainder containing 1% of one or two types and having a weight (concentration) ratio of Ca/S≧0.5゜REM/S≧1.0 is electrolyzed using a steel material consisting essentially of Fe. Hydrogen embrittlement resistance obtained by manufacturing a welded steel pipe, heating the electric resistance welded steel pipe to a temperature above the austenitizing temperature determined by its chemical composition and below 1100°C, quenching, and tempering at a temperature above 500°C and below AC3. A method for manufacturing a high-tensile resistance-welded steel pipe for oil wells having an excellent tensile strength of 65 kg/mA or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10792679A JPS5844726B2 (en) | 1979-08-24 | 1979-08-24 | Method for manufacturing high-strength ERW steel pipes for oil wells with excellent hydrogen embrittlement resistance |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10792679A JPS5844726B2 (en) | 1979-08-24 | 1979-08-24 | Method for manufacturing high-strength ERW steel pipes for oil wells with excellent hydrogen embrittlement resistance |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5633434A JPS5633434A (en) | 1981-04-03 |
JPS5844726B2 true JPS5844726B2 (en) | 1983-10-05 |
Family
ID=14471544
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP10792679A Expired JPS5844726B2 (en) | 1979-08-24 | 1979-08-24 | Method for manufacturing high-strength ERW steel pipes for oil wells with excellent hydrogen embrittlement resistance |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5844726B2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61124554A (en) * | 1984-11-20 | 1986-06-12 | Nippon Steel Corp | Steel for high toughness electric welded steel tube superior in sour resistance |
CN103397255B (en) * | 2013-08-09 | 2015-07-08 | 武汉钢铁(集团)公司 | High-performance free-cutting steel with small anisotropy |
-
1979
- 1979-08-24 JP JP10792679A patent/JPS5844726B2/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
JPS5633434A (en) | 1981-04-03 |
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