JPH02104634A - Austenitic steel having excellent corrosion resistance and high temperature strength - Google Patents
Austenitic steel having excellent corrosion resistance and high temperature strengthInfo
- Publication number
- JPH02104634A JPH02104634A JP25657288A JP25657288A JPH02104634A JP H02104634 A JPH02104634 A JP H02104634A JP 25657288 A JP25657288 A JP 25657288A JP 25657288 A JP25657288 A JP 25657288A JP H02104634 A JPH02104634 A JP H02104634A
- Authority
- JP
- Japan
- Prior art keywords
- corrosion resistance
- steel
- temperature strength
- high temperature
- content
- 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
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 37
- 239000010959 steel Substances 0.000 title claims abstract description 37
- 230000007797 corrosion Effects 0.000 title claims abstract description 32
- 238000005260 corrosion Methods 0.000 title claims abstract description 32
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 11
- 239000000126 substance Substances 0.000 claims abstract description 7
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 6
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 6
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 239000000463 material Substances 0.000 abstract description 9
- 230000000694 effects Effects 0.000 description 8
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 7
- 229910001566 austenite Inorganic materials 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 230000007774 longterm Effects 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 238000005728 strengthening Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 230000032683 aging Effects 0.000 description 2
- 239000010883 coal ash Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 229910001068 laves phase Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は、耐食性、特に耐高温腐食性および耐水蒸気
酸化性、および、高温強度がともに優れたオーステナイ
トステンレス鋼に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an austenitic stainless steel that has excellent corrosion resistance, particularly high temperature corrosion resistance and steam oxidation resistance, and high temperature strength.
［従来の技術］
ボイラチューブなどの熱交換器、化学工業などの反応管
用材料には、高温強度と耐食性とが必要とされており、
従来よりこの種の用途には、主として１８％Ｃｒ−８％
Ｎｉ系オーステナイトステンレス鋼が使用されていた。[Prior Art] Materials for heat exchangers such as boiler tubes and reaction tubes in the chemical industry are required to have high-temperature strength and corrosion resistance.
Traditionally, 18%Cr-8% has been mainly used for this type of application.
Ni-based austenitic stainless steel was used.
ところが、近年、ボイラ蒸気条件の高温高圧化および使
用燃料の石油焚きから微粉炭焚きへの転換等が検討され
ており、この種の装置用材料に必要とされる性能が高度
化してきたため、現用の１８−８系ステンレス鋼では高
温強度および耐食性のいずれもが不充分となった。However, in recent years, consideration has been given to increasing the temperature and pressure of boiler steam conditions and switching the fuel used from oil-fired to pulverized coal-fired, and the performance required for materials for this type of equipment has become more sophisticated, making it difficult to use them in current use. The 18-8 series stainless steel had insufficient high temperature strength and corrosion resistance.
耐高温腐食、耐水蒸気酸化といった耐食性の改善は、Ｃ
ｒの増量により容易になされることは既に知られている
。例えば、２５％Ｃｒ−２０％Ｎｉの５ｔＪＳ３１０鋼
および２１％Ｃｒ−３２％Ｎｉ −０，４ＡＱ−０，４
ＴｉのＮＣＦ３００Ｈ合金は、ともに１８−８系ステン
レス鋼に比べ、耐食性が改善されている。しかしながら
、このように高合金化された前記鋼は、１８−８系ステ
ンレス鋼よりも製造コストが大幅に上昇するという犠牲
をはらうにもかかわらず、高温強度に関しては、同等あ
るいはわずかながら低下してしまうことさえある。Improvements in corrosion resistance such as high-temperature corrosion resistance and steam oxidation resistance are achieved by C
It is already known that this can be easily achieved by increasing the amount of r. For example, 5t JS310 steel with 25%Cr-20%Ni and 21%Cr-32%Ni-0,4AQ-0,4
Both Ti NCF300H alloys have improved corrosion resistance compared to 18-8 stainless steel. However, these highly alloyed steels have the same or slightly lower high-temperature strength than 18-8 stainless steel, although they come at the cost of significantly higher production costs. Sometimes I even put it away.
耐食性を向上させ、同時に高温強度を改善したものとし
て１例えば、特公昭５７−１６４９７１号に、Ｃｒ増量
の場合のオーステナイト相維持に。For example, Japanese Patent Publication No. Sho 57-164971 discloses a method that improves corrosion resistance and high-temperature strength at the same time, and maintains the austenite phase when increasing the amount of Cr.
Ｎｉの代りにＮを使用するとともに、Ａｌ１およびＭｇ
を複合添加することにより、オーステナイト鋼の耐食性
のみならず高温強度の大巾改善を達成できるとの技術が
開示されている。Using N instead of Ni, Al1 and Mg
A technique has been disclosed in which it is possible to significantly improve not only the corrosion resistance but also the high temperature strength of austenitic steel by adding .
［発明が解決しようとする課題］
しかしながら、ＡＱおよびＭｇの複合添加が高温強度を
向上させる作用は明確でなく、且つ、ＡＱの過剰添加は
、クラスタ状の高融点結晶質Ａｎ、Ｏ，を生成し、熱間
、冷間圧延における表面性を劣化させる。さらに、ＡＱ
およびＭｇの添加により介在物、析出物が分離生成する
と、耐孔食性および耐誘性が特に劣化する問題点を有し
ている。[Problems to be Solved by the Invention] However, the effect of the combined addition of AQ and Mg on improving high-temperature strength is not clear, and excessive addition of AQ produces cluster-like high melting point crystals An, O, etc. and deteriorates surface properties during hot and cold rolling. Furthermore, A.Q.
When inclusions and precipitates are separated and formed due to the addition of Mg, pitting corrosion resistance and corrosion resistance particularly deteriorate.
このように、従来技術には、耐食性の改善を図るだめに
Ｃｒを増量すると、オーステナイト相安定のためにＮｉ
量も増量することが必要で、これにより高温強度が低下
してしまうという問題点がある。In this way, in the prior art, when increasing the amount of Cr to improve corrosion resistance, Ni is added to stabilize the austenite phase.
It is also necessary to increase the amount, which poses a problem in that high-temperature strength decreases.
従って、この発明の目的は、耐食性、特に高温腐食性お
よび耐水蒸気酸化性、および、高温強度がともに優れた
オーステナイトステンレス鋼を提供することにある。Therefore, an object of the present invention is to provide an austenitic stainless steel that has excellent corrosion resistance, particularly high temperature corrosion resistance and steam oxidation resistance, and high temperature strength.
［課題を解決するための手段および作用］発明者等は、
上述した問題点を解決するために鋭意努力した。その結
果、耐食性の改善を図るために、従来の１８−８系オー
ステナイトステンレス鋼よりもＣｒ含有量を増量すると
ともに、Ｃｒ含有量を増量した場合のオーステナイト相
の維持および高温強度の改善は、ＮおよびＮｂを適当量
添加することにより達成できることを知見した。[Means and effects for solving the problem] The inventors, etc.
We have made every effort to solve the problems mentioned above. As a result, in order to improve corrosion resistance, the Cr content was increased compared to conventional 18-8 austenitic stainless steel, and it was found that maintaining the austenite phase and improving high-temperature strength when increasing the Cr content It has been found that this can be achieved by adding an appropriate amount of Nb.
この発明は上述の知見に基づいてなされたものであって
、
Ｃ： ０．０２〜０．０６ｗｔ、％、
Ｓｉ：１．ＯＬ＃ｔ、％以下、
Ｍｎ：２．Ｏすｔ８％以下、
Ｎｉ：１３〜１８すｔ０％、
Ｃｒ：２０〜２５ｗｔ、％、
Ｎｂ： ０．６〜１．２ｗｔ、％、
さらに、必要に応じて。This invention was made based on the above-mentioned findings, and includes: C: 0.02 to 0.06 wt, %; Si: 1. OL#t, % or less, Mn: 2. Ost: 8% or less, Ni: 13 to 18 st, 0%, Cr: 20 to 25 wt, %, Nb: 0.6 to 1.2 wt, %, and further as necessary.
Ｂ ： ０．００１〜Ｏ，ＯＯ３ｖｔ、％、および 残部：Ｆｅおよび不可避的不純物 からなることに特徴を有するものである。B: 0.001~O, OO3vt, %, and Remainder: Fe and inevitable impurities It is characterized by the following.
次に、この発明の詳細な説明する。Next, the present invention will be explained in detail.
この発明において、鋼の化学成分組成を限定した理由を
以下に述べる。In this invention, the reason why the chemical composition of the steel is limited will be described below.
Ｃ：
Ｃは、高温用鋼として使用（以下使用という）される場
合、引張強さおよびクリープ破断強度を確保するために
有効な成分である。しかしながら、Ｃの含有量が０．０
２％＃ｔ、％未満では充分な効果が得られない、一方、
過剰な添加は、固溶化熱処理状態で未固溶の炭化物が残
存することとなり、高温強度に対する効果は向上せず、
むしろ粒界腐食に有害となる。従って、Ｃの含有量は０
．０２〜０・０６ｗｔ、％の範囲に限定すべきである。C: C is an effective component for ensuring tensile strength and creep rupture strength when used as a high-temperature steel (hereinafter referred to as "use"). However, the C content is 0.0
If it is less than 2%#t, sufficient effect cannot be obtained; on the other hand,
Excessive addition will result in undissolved carbides remaining in the solution heat treatment state, and the effect on high temperature strength will not improve.
Rather, it becomes harmful to intergranular corrosion. Therefore, the content of C is 0
．． It should be limited to a range of 0.02 to 0.06 wt.%.
Ｓｉ：
Ｓｉは、脱酸剤として添加される。しがしながら、Ｓｉ
の含有量が１，０ｔｒｔ、％を超えると、長時間使用後
にシグマ相の析出を生じ脆化するため、ＳＬの含有量は
１．Ｏｗｔ、％以下とすべきである。Si: Si is added as a deoxidizing agent. While doing so, Si
If the SL content exceeds 1.0 trt.%, sigma phase will precipitate and become brittle after long-term use, so the SL content should be 1.0 trt.%. Owt, % or less.
Ｍｎ：
Ｍｎは、脱酸およびオーステナイト相の安定のために有
用である。しかしながら、Ｍｎの含有量力２ 、０％＋
１．％を超えると効果が飽和するので、Ｍｎの含有量は
２ 、０ ｉｉｔ、％以下とすべきである。Mn: Mn is useful for deoxidizing and stabilizing the austenite phase. However, the Mn content is 2,0%+
1. If the Mn content exceeds 2.0%, the effect is saturated, so the Mn content should be 2.0% or less.
Ｎｉ：
Ｎｉは、安定なオーステナイト組織を得るために必須の
元素である。Ｃｒ量およびＮ量との関係から、Ｎｉの含
有量は１３ｗｔ、１以上を必要とする。Ni: Ni is an essential element to obtain a stable austenite structure. From the relationship with the amount of Cr and the amount of N, the Ni content needs to be 13 wt or more.
一方、Ｎｉの過剰な含有は、クリープ破断強度を低下さ
せるとともに、コストも上昇する。従って。On the other hand, excessive Ni content reduces creep rupture strength and increases cost. Therefore.
Ｎｉの含有量は１３〜１８ｗｔ、％の範囲に限定すべき
である。The Ni content should be limited to a range of 13-18 wt.%.
Ｃｒ：
Ｃｒは、耐酸化性、および、耐食性の改善に優れた効果
を示す。しかしながら、Ｃｒの含有量が２０ｔｇｔ、％
未満では、充分な耐食性が得られない。Cr: Cr shows excellent effects in improving oxidation resistance and corrosion resistance. However, the Cr content is 20tgt,%
If it is less than that, sufficient corrosion resistance cannot be obtained.
一方、２５ｖｔ、％を超えると、シグマ相の析出により
長時間使用後の脆化が顕著になる。従って、 Ｃｒの含
有量は２０〜２５すｔ０％の範囲に限定すべきである。On the other hand, if it exceeds 25vt%, embrittlement becomes noticeable after long-term use due to precipitation of sigma phase. Therefore, the Cr content should be limited to a range of 20 to 25%.
Ｎｂ：
Ｎｂは、Ｍ （Ｃ，Ｎ）型炭窒化物を形成し、クリープ
破断強度の改善に有効な元素である。 Ｎｂは、Ｃ量お
よびＮ量との関係から、０．６ｗｔ、１以上の添加を必
要とする。一方、Ｎｂを過剰に添加すると溶接性を損な
い、高温強度もがえって低下する。従って、Ｎｂの含有
量は０．６〜１．２ｖｔ、％の範囲に限定すべきである
。Nb: Nb forms M (C,N) type carbonitride and is an element effective in improving creep rupture strength. From the relationship with the amount of C and the amount of N, Nb needs to be added in an amount of 0.6 wt or more. On the other hand, if Nb is added excessively, weldability is impaired and high temperature strength is also reduced. Therefore, the Nb content should be limited to a range of 0.6 to 1.2 vt.%.
Ｎ ：
Ｎは、Ｃとともにオーステナイト生成元素であり、Ｃｒ
増量の場合のオーステナイト相の維持に、Ｎｉの代替と
して有用である。同時にＮは、ＮｂおよびＣとともにＮ
ｂ （Ｃ，Ｎ） の炭窒化物をつくり高温強度改善に
有効であるが、Ｎｂ量に対して（Ｃ＋Ｎ’）量が原子比
で１：１以上に添加されると、固溶化処理時に未固溶の
（Ｃ＋Ｎ）、使用時にＮｂ （Ｃ，Ｎ）として析出する
（Ｃ＋Ｎ） 以外に、使用時にＭ ２３ Ｃａとして
析出するＣ１および、使用時に固溶しているＮが存在す
ることになる。N: N is an austenite-forming element together with C, and Cr
It is useful as a substitute for Ni in maintaining the austenite phase in case of weight increase. At the same time, N together with Nb and C
b It is effective to create carbonitrides of (C,N) and improve high-temperature strength, but if the amount of (C+N') is added at an atomic ratio of 1:1 or more to the amount of Nb, unused materials will be removed during solution treatment. In addition to solid solution (C+N) and (C+N) that precipitates as Nb (C, N) during use, there are C1 that precipitates as M 23 Ca during use and N that is solid solution during use.
従って、通常のＮｂ （Ｃ，Ｎ） の析出強化に加え
、Ｍ ２３ Ｃ＠の析出強化、Ｎの固溶強化が加わり、
高温強度が著しく向上する。さらに、（Ｃ＋Ｎ）量がＮ
ｂ量に対して低い場合、炭窒化物を形成するＮｂ以外に
余剰となったＮｂは、Ｆｅ、Ｎｂ等のＬａｖｅｓ相を形
成し、長時間使用後の脆化をもたらす。Ｎの下限値は、
従って、（Ｃ＋Ｎ）＞Ｎｂ（原子量％）より決まる。原
子量比をおおよそ、Ｃ： Ｎ ： Ｎｂ−Ｃ）（ｗｔ、
％）となる。しかしながら、Ｎは過剰に添加すると多、
量の窒化物を生成し、長時間使用後の脆化をもたらすた
め、上限を０．２０ｗｔ、％とす（ｗｔ、幻）＜Ｎ≦０
．２０ｗｔ、％とすべきである。Therefore, in addition to the usual precipitation strengthening of Nb (C, N), precipitation strengthening of M 23 C@ and solid solution strengthening of N are added.
High temperature strength is significantly improved. Furthermore, the amount of (C+N) is N
When the amount of b is low, excess Nb other than Nb forming carbonitrides forms Laves phases such as Fe and Nb, resulting in embrittlement after long-term use. The lower limit of N is
Therefore, it is determined by (C+N)>Nb (atomic weight %). The atomic weight ratio is approximately C: N: Nb-C) (wt,
%). However, if N is added in excess,
The upper limit is set at 0.20wt,% (wt, phantom) <N≦0 because it generates a large amount of nitrides and causes embrittlement after long-term use.
．． It should be 20wt,%.
Ｂ ：
Ｂは１粒界を強化し、高温強度特性を改善するのに有効
である。しかしながら、Ｂの含有量が０．００１ｗｔ、
％未満では効果がない。一方、過剰に添加すると溶接性
が劣化する。従って、Ｂの含有量は０．００１〜０．０
０３ｗｔ、％の範囲に限定すべきである。B: B is effective in strengthening one grain boundary and improving high temperature strength properties. However, the content of B is 0.001wt,
Less than % has no effect. On the other hand, when added in excess, weldability deteriorates. Therefore, the content of B is 0.001 to 0.0
It should be limited to a range of 0.03wt.%.
［実施例］ 次に、この発明を実施例によりさらに詳しく説明する。[Example] Next, the present invention will be explained in more detail with reference to Examples.
第１表に示す化学成分組成を有する本発明鋼面１１〜２
０および比較鋼＆１〜１０の供試鋼を、いずれも２５ｋ
ｇ大気溶製し、熱間圧延後、固溶化熱処理を行なった。Invention steel surfaces 11-2 having the chemical composition shown in Table 1
0 and comparison steel & test steels 1 to 10, both 25k
g. After being melted in the atmosphere and hot rolled, solution heat treatment was performed.
固溶化熱処理はいずれも１２００℃にて行なった。All solution heat treatments were performed at 1200°C.
これらの供試材について、７００℃、応力１２ｋｇ ／
ｍ ” の−水準にてクリープ破断試験を行なった。For these test materials, 700℃, stress 12kg/
A creep rupture test was conducted at a -level of m''.
その結果を第１表に破断時間および破断伸びとして示し
た。また、これらの供試材について、７００℃で３００
０時間加熱後、０℃にてシャルピー衝撃試験を行なった
。その結果についても第１表にシャルピー衝撃値として
併せて示した。The results are shown in Table 1 as time to break and elongation at break. In addition, for these test materials, 300°C at 700°C
After heating for 0 hours, a Charpy impact test was conducted at 0°C. The results are also shown in Table 1 as Charpy impact values.
さらに、これらの供試材について、石炭灰塗布による高
温腐食試験を行ない、その結果を第１図に示した。試験
条件等は、以下に示す通りである。Further, these test materials were subjected to a high temperature corrosion test by applying coal ash, and the results are shown in FIG. The test conditions etc. are as shown below.
試験条件
６５０℃Ｘｌ０Ｈｒ
塗布灰
３４％Ｎａ２５ｏ、 −４１％に、５ｏ４−２５％Ｆｅ
、 Ｏ。Test conditions: 650°C
, O.
雰囲気 １％５ｏ２−５１０．−１５％ＣＯ２−ｂａｌ、Ｎ、。atmosphere 1%5o2-510. -15% CO2-bal, N,.
また、これらの供試材について、７００℃×５００ Ｈ
ｒにおける水蒸気酸化試験を行ない、その結果を第２図
に示した。In addition, for these test materials, 700℃×500H
A steam oxidation test was carried out at 100 mL, and the results are shown in FIG.
第１図および第２図に示すように、本発明鋼Ｎα１１〜
２０は、いずれも従来の５ＵＳ３１０Ｓ鋼の比較鋼Ｎａ
５、ＮＣＦ３００Ｈ合金の比較鋼Ｎａ ６と同等の耐食
性を有していることがわかる。さらに１本発明鋼Ｎ１１
ｌｌ〜２０は、いずれも既存の高Ｃｒ鋼と同様に、耐食
性の点で、１８−８系オーステナイトステンレス鋼を大
きく上回ることがわかる。As shown in FIGS. 1 and 2, the present invention steel Nα11~
20 are comparison steel Na of conventional 5US310S steel.
5. It can be seen that the NCF300H alloy has the same corrosion resistance as the comparison steel Na 6. One more invention steel N11
It can be seen that all of steels ll to 20, like existing high Cr steels, greatly exceed 18-8 series austenitic stainless steel in terms of corrosion resistance.
第３図は、Ｎｂ、Ｃ，Ｎ の添加量の関係を示すもので
ある。第３図において示す記号は以下の通りである。FIG. 3 shows the relationship between the amounts of Nb, C, and N added. The symbols shown in FIG. 3 are as follows.
Ｏ・・・Ｂ添加鋼、
ｌ・・・クリープ破断時間１００．ＯＨｒ以下、（７０
０℃−１２ｋｇ／ｍａ”）、
−７・・・シャルピー衝撃値（０℃）５ｋｇ−ｍ／ｍ２
以下、（７００℃−３０００Ｈｒ時効後）。O... B-added steel, l... Creep rupture time 100. OHr or less, (70
0℃-12kg/ma"), -7... Charpy impact value (0℃) 5kg-m/m2
Below, (after aging at 700°C and 3000 hours).
Δ・・・Ｃｒ含有量２５ｗｔ、％以上。Δ...Cr content 25wt% or more.
第３図に示すように、Ｎｂ： （Ｃ＋−Ｎ）＝１：１
の線を境とし、（Ｃ＋−Ｎ）＞Ｎｂにおいて、クリープ
破断時間およびシャルピー衝撃値（時効後）とも良好な
値となることがわかる。As shown in Figure 3, Nb: (C+-N)=1:1
It can be seen that when (C+-N)>Nb, the creep rupture time and Charpy impact value (after aging) are both good values.
第１表および第１図〜第３図に示すように、比較ｌＩＮ
α１〜４は、従来の１８−８系オーステナイトステンレ
ス鋼であり、Ｃｒ量が低く、耐食性が期待できない。さ
らに、クリープ破断時間も短かかった。As shown in Table 1 and Figures 1 to 3, the comparative lIN
α1 to α4 are conventional 18-8 austenitic stainless steels, which have a low Cr content and cannot be expected to have corrosion resistance. Furthermore, the creep rupture time was also short.
比較鋼面５は、５ＵＳ３１０Ｓ鋼であり、耐食性は良好
であるが、クリープ破断時間が短かかった。Comparative steel surface 5 was 5US310S steel, which had good corrosion resistance but a short creep rupture time.
比較鋼＆６は、ＮＣＦ３００Ｈ合金であり、耐食性は良
好であるが、高合金化したにもかかわらず、クリープ破
断時間が短かかった。Comparative steel &6 is an NCF300H alloy, and has good corrosion resistance, but has a short creep rupture time despite being highly alloyed.
比較鋼ＮＧ？、８．および特開昭５７−１６４９７１号
公報に記載されている鋼組成である比較鋼Ｎａ ９．１
０は、耐食性およびクリープ破断時間とも良好であるが
、長時間加熱後の脆化が認められた。Comparison steel NG? , 8. and comparative steel Na 9.1, which has a steel composition described in JP-A No. 57-164971.
No. 0 had good corrosion resistance and creep rupture time, but embrittlement was observed after long-term heating.
これに対して本発明鋼＆１１〜２０は、いずれもＣ，Ｎ
に対してバランスよ＜Ｎｂを添加し、Ｎｉ量も適度に抑
えていることから、クリープ破断時間が比較鋼に比べ著
しく良好であった。また、耐食性も比較鋼Ｎｏ ５〜１
０とほぼ等しく、比較鋼Ｎα１〜４の１８−８系オース
テナイトステンレス鋼に比べ著しく良好であった。さら
に、長時間加熱後の脆化も認められなかった。On the other hand, steels of the present invention &11 to 20 are all C, N
The creep rupture time was significantly better than that of the comparative steel because Nb was added to the steel and the amount of Ni was moderately suppressed. In addition, the corrosion resistance is also comparable to steel No. 5 to 1.
0, which was significantly better than the 18-8 austenitic stainless steel with comparative steels Nα1 to Nα4. Furthermore, no embrittlement was observed after long-term heating.
［発明の効果］
以上説明したように、この発明によれば、Ｃｒ量を１８
−８系オーステナイトステンレス鋼よ番も増量し、Ｎ添
加でＮｉの増量を抑制するとと膚に、Ｎｂ、Ｈの添加に
よって高温強度を改善し１いる。従って、既存の高Ｃｒ
ｆＲと同様に耐食性０点で１８−８系鋼を大きく上回る
高温強度を備ｊており、高価な合金成分を抑えているこ
とから２価に製造することができ、ボイラや化学プラン
を等の高温機器材料として大きな効果がある。[Effect of the invention] As explained above, according to this invention, the amount of Cr is reduced to 18
The amount of -8 series austenitic stainless steel is also increased, and the addition of N suppresses the increase in Ni, while the addition of Nb and H improves high temperature strength. Therefore, the existing high Cr
Like fR, it has high-temperature strength that far exceeds that of 18-8 steel with zero corrosion resistance, and because it contains fewer expensive alloy components, it can be manufactured into divalent steel, making it suitable for boilers, chemical plans, etc. It is highly effective as a material for high-temperature equipment.
第１図は石炭灰塗布による高温腐食試験の結肩を示すグ
ラフ、第２図は７００℃における水蒸喉酸化試験の結果
を示すグラフ、第３図はＮｂ、 ＣＮの添加量の関係を
示すグラフである。Figure 1 is a graph showing the shoulders of a high-temperature corrosion test using coal ash application, Figure 2 is a graph showing the results of a water vapor throat oxidation test at 700°C, and Figure 3 is a graph showing the relationship between the amounts of Nb and CN added. It is a graph.
Claims (1)
たオーステナイト鋼。 ２ Ｃ：０．０２〜０．０６ｗｔ．％、 Ｓｉ：１．０ｗｔ．％以下、 Ｍｎ：２．０ｗｔ．％以下、 Ｎｉ：１３〜１８ｗｔ．％、 Ｃｒ：２０〜２５ｗｔ．％、 Ｎｂ：０．６〜１．２ｗｔ．％、 Ｂ：０．００１〜０．００３ｗｔ．％、 Ｎ：▲数式、化学式、表等があります▼ および、 残部：Ｆｅおよび不可避的不純物 からなることを特徴とする耐食性および高温強度に優れ
たオーステナイト鋼。[Claims] 1C: 0.02 to 0.06wt. %, Si: 1.0wt. % or less, Mn: 2.0wt. % or less, Ni: 13 to 18 wt. %, Cr: 20-25wt. %, Nb: 0.6-1.2wt. %, N: ▲Mathematical formulas, chemical formulas, tables, etc.▼ And, Balance: Austenitic steel with excellent corrosion resistance and high-temperature strength, characterized by consisting of Fe and unavoidable impurities. 2C: 0.02-0.06wt. %, Si: 1.0wt. % or less, Mn: 2.0wt. % or less, Ni: 13 to 18 wt. %, Cr: 20-25wt. %, Nb: 0.6-1.2wt. %, B: 0.001-0.003wt. %, N: ▲Mathematical formulas, chemical formulas, tables, etc.▼ And, Balance: Austenitic steel with excellent corrosion resistance and high-temperature strength, characterized by consisting of Fe and unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25657288A JPH02104634A (en) | 1988-10-12 | 1988-10-12 | Austenitic steel having excellent corrosion resistance and high temperature strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25657288A JPH02104634A (en) | 1988-10-12 | 1988-10-12 | Austenitic steel having excellent corrosion resistance and high temperature strength |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02104634A true JPH02104634A (en) | 1990-04-17 |
Family
ID=17294500
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25657288A Pending JPH02104634A (en) | 1988-10-12 | 1988-10-12 | Austenitic steel having excellent corrosion resistance and high temperature strength |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02104634A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012255198A (en) * | 2011-06-10 | 2012-12-27 | Nippon Steel & Sumitomo Metal Corp | Method for producing austenitic stainless steel pipe, and austenitic stainless steel pipe |
-
1988
- 1988-10-12 JP JP25657288A patent/JPH02104634A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012255198A (en) * | 2011-06-10 | 2012-12-27 | Nippon Steel & Sumitomo Metal Corp | Method for producing austenitic stainless steel pipe, and austenitic stainless steel pipe |
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