JPS62267454A - Austenitic stainless steel having superior creep strength - Google Patents

Austenitic stainless steel having superior creep strength

Info

Publication number
JPS62267454A
JPS62267454A JP11053486A JP11053486A JPS62267454A JP S62267454 A JPS62267454 A JP S62267454A JP 11053486 A JP11053486 A JP 11053486A JP 11053486 A JP11053486 A JP 11053486A JP S62267454 A JPS62267454 A JP S62267454A
Authority
JP
Japan
Prior art keywords
steel
creep strength
austenitic stainless
less
strength
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.)
Pending
Application number
JP11053486A
Other languages
Japanese (ja)
Inventor
Yusuke Minami
雄介 南
Hidemichi Kimura
秀途 木村
Manabu Tamura
学 田村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Engineering Corp
Original Assignee
NKK Corp
Nippon Kokan Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NKK Corp, Nippon Kokan Ltd filed Critical NKK Corp
Priority to JP11053486A priority Critical patent/JPS62267454A/en
Publication of JPS62267454A publication Critical patent/JPS62267454A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To provide creep strength higher than that of a generally used steel to a dead soft steel by adding proper amounts of Ti and P to the dead soft steel having a specified composition. CONSTITUTION:The composition of an austenitic stainless steel is composed of, by weight, <=0.01% C, <=1.0% Si, <=2.0% Mn, 0.03-0.08% P, <=0.03% S, 10-18% Ni, 13-20% Cr, 1.5-2.5% Ti, <=0.02% T.N and the balance Fe with inevitable impurities. The proper amount of Ti added is effective in improving the creep strength of the dead soft steel and the weldability of the steel is not deteriorated by the proper amount of P added. The corrosion resistance and the strength at high temp. are effectively improved by further adding 1.5-3.0% Mo and/or 2.5-3.5% Cu.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、高温用鋼に係り特にクリープ強度に曖れた
オーステナイトステンし・ス鋼に関するものである。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to high-temperature steels, and particularly relates to austenitic stainless steels having poor creep strength.

〔従来技術〕[Prior art]

高温用のオーステナイトステンレス鋼として現在実用化
されている鋼としては、  5US304.316.3
21.347鋼等がある。
Steels currently in practical use as high-temperature austenitic stainless steels include 5US304.316.3.
21.347 steel etc.

これらの鋼の高温での強化因子は、炭化物が主体である
。例えば、5US304.316ではCr3C6,5U
S321ではT i C、5US347ではNbC等で
ある。
The strengthening factor of these steels at high temperatures is mainly carbides. For example, in 5US304.316, Cr3C6,5U
S321 is T i C, 5US347 is NbC, etc.

高温用材料に要求されろ特性としては、高温強度の他に
耐食性が挙げられろ。然し耐食性に対し □て炭素は有
害であり、極力低炭素鋼にすることが望まれるが、高温
強度が著しく低下する。
In addition to high-temperature strength, corrosion resistance is also required for high-temperature materials. However, carbon is harmful to corrosion resistance, and although it is desirable to use as low-carbon steel as possible, the high-temperature strength will drop significantly.

このため極低炭素鋼では、高温強度改善のため高窒素と
した5US304LN、 5US316LN鋼等が開発
されているが、何れも長時間のクリープ破断強度が低下
するという問題が生じている。
For this reason, ultra-low carbon steels such as 5US304LN and 5US316LN steels containing high nitrogen have been developed to improve high-temperature strength, but both have the problem of reduced long-term creep rupture strength.

又T i 、 N b @添加し炭素をTiC,NbC
で固定する5US321.5US347 yIも極低炭
素鋼に比べて充分な耐食性を有してない。
Also, T i , N b @ is added to convert carbon into TiC, NbC
5US321.5US347yI, which is fixed with 5US321.5US347yI, also does not have sufficient corrosion resistance compared to ultra-low carbon steel.

そのため極低炭素であり、且つ高温強度に擾れた鋼の開
発が望まれている。
Therefore, there is a desire to develop steel that has extremely low carbon content and has excellent high-temperature strength.

一方耐食性の面から炭素量を0.01wtに以下にする
ことで、高温水中等におけろ応力腐食割れが防止出来る
ことは良く知られているが、上述したように極低炭素で
は、高温強度が充分ではない。
On the other hand, it is well known that stress corrosion cracking can be prevented even in high-temperature water by reducing the carbon content to 0.01wt or less from the perspective of corrosion resistance. is not enough.

〔発明の解決すべき問題点〕[Problems to be solved by the invention]

今 本発明は、極低炭素鋼に対し、Ti、Pを適量添加する
ことにより、現用鋼以上のクリープ強度を有するオース
テナイトステンL・ス鋼を提供することを目的とするも
のである。
The object of the present invention is to provide an austenitic stainless L/S steel having a creep strength higher than that of current steel by adding appropriate amounts of Ti and P to ultra-low carbon steel.

〔解決するための手段〕[Means to solve]

本発明は、T i 、 Pを適量添加することにより、
極低炭素においても現用の18−8系ステ、ルス鋼以上
のクリープ強度を有する鋼を見出しなされたものである
In the present invention, by adding appropriate amounts of T i and P,
Even at extremely low carbon levels, we have discovered a steel that has a creep strength higher than that of the currently used 18-8 steel and steel.

即ち、本発明の第1発明は、重量基準にて、C:0.0
IX以下、Si:]、0%以下、Mn:2.0%以下、
P:  0.003〜0108%、  S :  0.
0.03%以下、N i :  10−.18%、Cr
 :  13〜20%、T i :  1.5〜2.5
J  T 、  N :  0.02X以下、残部Fe
及び不可避不純物からなるりIJ−プ強度に曖れたオー
ステナイトステンし・ス鋼であり0、 第2発明は、第1発明の成分に加わるに、Mo:1、!
+〜3.0%、 Cu : 2.5〜3.5Xの一種又
は二種を含むことからなるクリープ強度に擾れたオース
テナイトステンレス鋼である。
That is, in the first aspect of the present invention, on a weight basis, C: 0.0
IX or less, Si: ], 0% or less, Mn: 2.0% or less,
P: 0.003-0108%, S: 0.
0.03% or less, Ni: 10-. 18%, Cr
: 13-20%, Ti: 1.5-2.5
JT, N: 0.02X or less, balance Fe
The second invention is an austenitic stainless steel containing unavoidable impurities and having ambiguous IJ-P strength.The second invention has Mo: 1,!
It is an austenitic stainless steel with poor creep strength, containing one or both of the following: +~3.0% Cu: 2.5~3.5X.

〔作用〕[Effect]

本発明鋼の成分限定理由について以下に述べる。 The reason for limiting the composition of the steel of the present invention will be described below.

C:#4食性に有害な元素であるため、極力少ない方が
望ましく 、0,01wtX以下にすれば実用環境中で
は十分な耐食性が得られるため上限を0.01wtxに
する。
C: #4 Since it is an element harmful to corrosion, it is desirable to reduce it as much as possible, and if it is less than 0.01 wtx, sufficient corrosion resistance can be obtained in a practical environment, so the upper limit is set to 0.01 wtx.

Si:脱酸剤又は耐酸化性改善のため添加させるが、過
剰の添加はシグマ相の析出を促進させるため、上限を1
 wtXにする。
Si: Added as a deoxidizer or to improve oxidation resistance, but excessive addition promotes precipitation of sigma phase, so the upper limit is set to 1.
Make it wtX.

Mn:脱酸、脱硫を目的に添加されるが、2 wtXを
超える添加はその効果が有効でないため、上限を2 w
tZにする。
Mn: It is added for the purpose of deoxidation and desulfurization, but the effect is not effective if it exceeds 2 wtX, so the upper limit is set to 2 w
Make it tZ.

S:fA間加工性に有害な元素であ)l 、0.03*
tXを超えると製造時に熱間加工割れを生じるため、上
限を0.03*tXニする。
S: fA is an element harmful to machinability) l, 0.03*
If it exceeds tX, hot working cracks will occur during manufacturing, so the upper limit is set to 0.03*tX.

N1ニオ−ステナイト相生成のため必要な元素であり、
10w1未瀾ではマルテシサイト或いはフェライ)・相
を生じろため10+vtX以上の含有が必要である。又
Niは高価な元素であるため、過剰の含有は経済的に有
利でないため上限を18wt%にする。
It is an element necessary for the formation of N1 niostenite phase,
If 10w1 is not mixed, a martesisite or ferrite phase will occur, so it is necessary to contain 10+vtX or more. Further, since Ni is an expensive element, excessive content is not economically advantageous, so the upper limit is set at 18 wt%.

Cr:耐酸化性、耐食性から13wt*以上必要である
が、過剰の含有はオーステナイト相の安定のためNl量
を増す必要があること、シグマ相を生成しやすくするこ
とから上限を2(lvt2にする。
Cr: 13 wt* or more is required for oxidation resistance and corrosion resistance, but excessive content requires an increase in the amount of Nl to stabilize the austenite phase and makes it easier to generate the sigma phase, so the upper limit is set to 2 (lvt2). do.

T1:クリープ強度の向上に有効な元素であるが、1、
5wtz未満で(よりリープ強度の改善が十分でなく、
2、5wt*を超丸ると脆化相を生成し、靭性を損なう
ためその含有範囲を1.5〜2.5wtににする。
T1: An element effective in improving creep strength, but 1,
Below 5wtz (improvement in leap strength is not sufficient,
If 2.5 wt* is too round, a brittle phase will be generated and the toughness will be impaired, so the content range is set to 1.5 to 2.5 wt.

T、N:窒素は溶製中T i Nを生成し、クリープ強
度に有効なTi量を減じるためその上限を0.02w(
Xにする。
T, N: Nitrogen generates TiN during melting and reduces the amount of Ti effective for creep strength, so the upper limit is set at 0.02w (
Make it X.

Mo、Cu:何れも耐食性、高温強度の改善に有効な元
素であるが、含有量が少ない場合その効果が認められず
、又過剰の含有は高価な元素であるため、経済性を損な
うことから、その含有量を夫々1.5〜3.0wl、 
2.5〜3.5zにする。
Mo, Cu: Both are effective elements for improving corrosion resistance and high-temperature strength, but if the content is small, the effect will not be recognized, and if the content is excessive, it will impair economic efficiency as they are expensive elements. , the content of which is 1.5 to 3.0 wl, respectively.
Set it to 2.5-3.5z.

P:本発明の特徴の一つであり、0.03wtX未満て
は効果が認められず、又0.08wtxを超えると溶接
性を損なうため、その範囲を0.03wt*≦P≦0゜
08+vtXにする。
P: This is one of the characteristics of the present invention, and if it is less than 0.03wtX, no effect will be observed, and if it exceeds 0.08wtx, weldability will be impaired, so the range is 0.03wt*≦P≦0°08+vtX Make it.

次に本発明の実施例について述べる。Next, examples of the present invention will be described.

〔実施例〕〔Example〕

次表に示したNo、 1〜11の鋼(本発明鋼No、 
1〜6、比較鋼No、 7〜11)を真空溶製し、10
kg消塊とした後、熱間圧延にて12mmtの板とした
Steels No. 1 to 11 shown in the following table (invention steel No.
1 to 6, comparative steel No. 7 to 11) were vacuum melted, and 10
It was made into a 12 mm thick plate by hot rolling.

溶体化処理を1050℃にて行ない、平行部径6關φ、
標点距離30IIIII+の試験片を採取し、700’
Cにてクリープ試験を行った。
Solution treatment was carried out at 1050℃, parallel part diameter 6 φ,
A test piece with a gauge length of 30III+ was taken, and the gauge length was 700'
A creep test was conducted at C.

比較鋼No、10.11は、1150℃の溶体化処理条
件で行った。
Comparative steel No. 10.11 was subjected to solution treatment at 1150°C.

クリープ試験は応力10kgf/鴎”で行い、評点距離
30間間の伸びを連続的に測定し、定常クリープ速度を
求めた。
The creep test was carried out under a stress of 10 kgf/Kuji, and the elongation between 30 rating distances was continuously measured to determine the steady-state creep rate.

本発明鋼の特徴はT i 、 Pを適量添加することに
よりクリープ強度が改善される点である。
A feature of the steel of the present invention is that creep strength is improved by adding appropriate amounts of Ti and P.

比較鋼No、 7はTi、P量とも本発明範囲内の場合
であり、クリープ強度は9.0xlO−’xハと著しく
低い。P量を本発明範囲内にすることにより比較fr4
!&18に示すようにクリープ強度は向上するが、Ti
旦が低いため同程度のPiである本発明川魚1に比ベク
リープ強度は劣る。
Comparative steel No. 7 has both Ti and P contents within the range of the present invention, and the creep strength is extremely low at 9.0xlO-'xha. By setting the P amount within the range of the present invention, comparison fr4
! As shown in &18, the creep strength improves, but Ti
Since the temperature is lower, the creep strength is inferior to the river fish 1 of the present invention, which has the same Pi.

又T1量を本発明範囲内とした比較fi)Jo、9のク
リープ強度は2.9X10−.03%ハと向上するが、
P量が低いため本発明鋼程の強度は得られない。
In addition, the creep strength of the comparison fi) Jo, 9 where the T1 amount was within the range of the present invention was 2.9X10-. Although it improves by 0.3%,
Since the amount of P is low, strength as high as that of the steel of the present invention cannot be obtained.

現用鋼として広く用いられている5US321[(、3
47H(比較filJo、IO,II)に比べても本発
明鋼No、 1〜3は格段と優れたクリープ強度を有し
ており、更にM o 。
5US321 [(, 3
Compared to 47H (comparison filJo, IO, II), the invention steel Nos. 1 to 3 have significantly superior creep strength, and furthermore, M o .

Cu、或いはMoとCuを含有させた本発明n444〜
6はより優れたクリープ強度を示すことは本実施例より
明らかである。
Invention n444 containing Cu or Mo and Cu
It is clear from this example that No. 6 exhibits superior creep strength.

〔発明の効果〕〔Effect of the invention〕

本発明のクリープ強度に漫れたオーステナイトステンレ
ス鋼は、極低炭素鋼であってもTi、P量を適量含有さ
せることにより、現用y4息上のクリープ強度を有する
ものである。
The austenitic stainless steel of the present invention, which has excellent creep strength, has a creep strength that exceeds that of current Y4 steels by containing appropriate amounts of Ti and P even if it is an extremely low carbon steel.

Claims (2)

【特許請求の範囲】[Claims] (1)重量基準にて、C:0.01%以下、Si:1.
0%以下、Mn:2.0%以下、P:0.003〜0.
08%、S:0.03%以下、Ni:10〜18%、C
r:13〜20%、Ti:1.5〜2.5%、T.N:
0.02%以下、残部Fe及び不可避不純物からなるこ
とを特徴とするクリープ強度に優れたオーステナイトス
テンレス鋼。
(1) Based on weight, C: 0.01% or less, Si: 1.
0% or less, Mn: 2.0% or less, P: 0.003 to 0.
08%, S: 0.03% or less, Ni: 10-18%, C
r: 13-20%, Ti: 1.5-2.5%, T. N:
An austenitic stainless steel with excellent creep strength characterized by comprising 0.02% or less, the balance being Fe and unavoidable impurities.
(2)重量基準にて、C:0.01%以下、Si:1.
0%以下、Mn:2.0%以下、P:0.003〜0.
08%、S:0.03%以下、Ni:10〜18%、C
r:13〜20%、Ti:1.5〜2.5%、T.N:
0.02%以下、及びMo:1.5〜3.0%、Cu:
2.5〜3.5%の一種又は二種を含み、残部Fe及び
不可避不純物からなることを特徴とするクリープ強度に
優れたオーステナイトステンレス鋼。
(2) Based on weight, C: 0.01% or less, Si: 1.
0% or less, Mn: 2.0% or less, P: 0.003 to 0.
08%, S: 0.03% or less, Ni: 10-18%, C
r: 13-20%, Ti: 1.5-2.5%, T. N:
0.02% or less, Mo: 1.5 to 3.0%, Cu:
An austenitic stainless steel with excellent creep strength, characterized in that it contains 2.5 to 3.5% of one or both of the elements, with the remainder consisting of Fe and unavoidable impurities.
JP11053486A 1986-05-16 1986-05-16 Austenitic stainless steel having superior creep strength Pending JPS62267454A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11053486A JPS62267454A (en) 1986-05-16 1986-05-16 Austenitic stainless steel having superior creep strength

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11053486A JPS62267454A (en) 1986-05-16 1986-05-16 Austenitic stainless steel having superior creep strength

Publications (1)

Publication Number Publication Date
JPS62267454A true JPS62267454A (en) 1987-11-20

Family

ID=14538246

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11053486A Pending JPS62267454A (en) 1986-05-16 1986-05-16 Austenitic stainless steel having superior creep strength

Country Status (1)

Country Link
JP (1) JPS62267454A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008087807A1 (en) 2007-01-15 2008-07-24 Sumitomo Metal Industries, Ltd. Austenitic stainless steel welded joint and austenitic stainless steel welding material
WO2009093676A1 (en) 2008-01-25 2009-07-30 Sumitomo Metal Industries, Ltd. Welding material and welded joint structures

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008087807A1 (en) 2007-01-15 2008-07-24 Sumitomo Metal Industries, Ltd. Austenitic stainless steel welded joint and austenitic stainless steel welding material
US8137613B2 (en) 2007-01-15 2012-03-20 Sumitomo Metal Industries, Ltd. Austenitic stainless steel welded joint and austenitic stainless steel welding material
WO2009093676A1 (en) 2008-01-25 2009-07-30 Sumitomo Metal Industries, Ltd. Welding material and welded joint structures
US7951469B2 (en) 2008-01-25 2011-05-31 Sumitomo Metal Industries, Ltd. Welding material and welded joint structure
US8158274B2 (en) 2008-01-25 2012-04-17 Sumitomo Metal Industries, Ltd. Welding material and welded joint structure

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