JPH07103448B2 - Heat-resistant steel with excellent carburization resistance and creep rupture strength - Google Patents
Heat-resistant steel with excellent carburization resistance and creep rupture strengthInfo
- Publication number
- JPH07103448B2 JPH07103448B2 JP33627790A JP33627790A JPH07103448B2 JP H07103448 B2 JPH07103448 B2 JP H07103448B2 JP 33627790 A JP33627790 A JP 33627790A JP 33627790 A JP33627790 A JP 33627790A JP H07103448 B2 JPH07103448 B2 JP H07103448B2
- Authority
- JP
- Japan
- Prior art keywords
- creep rupture
- rupture strength
- heat
- carburization resistance
- resistant steel
- 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 - Lifetime
Links
Landscapes
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、石油化学工業におけるナフサ、エタン等の炭
化水素の熱分解・改質反応に使用される反応管等の材料
として好適な耐熱鋼に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a heat-resistant steel suitable as a material for a reaction tube or the like used in the thermal decomposition / reforming reaction of hydrocarbons such as naphtha and ethane in the petrochemical industry. Regarding
［従来技術及びその問題点］ 石油化学工業における炭化水素の熱分解・改質反応で
は、炭化水素の熱分解過程にて、カーボンが反応管の壁
面に付着し、そのカーボンが管の内部に拡散していくた
め、いわゆる浸炭現象が生じて反応管の材質が著しく劣
化する問題がある。[Prior art and its problems] In the pyrolysis and reforming reactions of hydrocarbons in the petrochemical industry, carbon adheres to the wall surface of the reaction tube during the pyrolysis process of hydrocarbons, and the carbon diffuses inside the tube. Therefore, there is a problem that a so-called carburization phenomenon occurs and the material of the reaction tube is significantly deteriorated.
この用途に使用される材料として、従来から、ASTMに規
定されたHP系材料（25Cr−35Ni）や、さらにNb、Ｗ、Mo
等を添加した改良HP系材料等が広く使用されている。As materials used for this purpose, HP-based materials (25Cr-35Ni), which have been conventionally specified in ASTM, and Nb, W, Mo
Improved HP-based materials with the addition of etc. are widely used.
ところで、最近では、操業温度の高温化が進んでおり、
上記材料の場合、1100℃以上の温度で使用されると、十
分の耐浸炭性を発揮できないばかりか、クリープ破断強
度の著しい低下を招くという問題がある。このため、11
00℃以上の温度域での使用に耐え得るすぐれた耐浸炭性
と高いクリープ破断強度を備えた材料が要請されてい
る。By the way, recently, the operating temperature is getting higher,
When the above materials are used at a temperature of 1100 ° C. or higher, not only sufficient carburization resistance cannot be exhibited, but also the creep rupture strength is significantly reduced. Therefore, 11
A material having excellent carburization resistance and high creep rupture strength that can withstand use in a temperature range of 00 ° C or higher is required.
本発明はかかる要請を満たした新規な材料を提供するも
のである。The present invention provides a novel material satisfying such a demand.
［技術的手段及び作用］ 本発明の耐熱鋼は、重量％にて、C:0.3〜1.5％、Si:2％
を超えて３％以下、Mn:2％以下、Cr:20〜30％、Ni:25〜
40％、Al:0.2〜2.0％、Nb:0.2〜2.0％、W:0.2〜2.0％お
よび残部実質的にFeからなる成分組成を有している。[Technical Means and Actions] The heat-resistant steel of the present invention contains C: 0.3 to 1.5% and Si: 2% by weight.
3% or less, Mn: 2% or less, Cr: 20-30%, Ni: 25-
It has a composition of 40%, Al: 0.2 to 2.0%, Nb: 0.2 to 2.0%, W: 0.2 to 2.0% and the balance substantially Fe.
本発明の耐熱鋼は、必要に応じて、さらにTi:0.01〜0.3
％を含有することもできる。The heat-resistant steel of the present invention, if necessary, further Ti: 0.01 ~ 0.3
% May also be included.
本発明の耐熱鋼は、1100℃以上の温度域の使用におい
て、すぐれた耐浸炭性と高いクリープ破断強度を具備し
ている。The heat-resistant steel of the present invention has excellent carburization resistance and high creep rupture strength when used in a temperature range of 1100 ° C or higher.
［成分限定理由］ 本発明の耐熱鋼の成分限定理由は次の通りである。[Reasons for Limiting Components] The reasons for limiting the components of the heat resistant steel of the present invention are as follows.
C:0.3〜1.5％ Ｃ量の増加に伴って溶融温度が低下するため、鋳造性が
向上する。しかし、あまりに含有量が多くなると、材料
の劣化が進み、鋳造割れや溶接割れを発生する。このた
め、Ｃ含有量の上限は1.5％とする 他方、Ｃ含有量が0.3％より少ないと高温での使用中に
シグマ相が析出し、延性の著しい低下を招く。このた
め、下限は0.3％に規定する。C: 0.3-1.5% Since the melting temperature decreases as the C content increases, the castability improves. However, if the content is too large, the deterioration of the material proceeds, and casting cracks and welding cracks occur. For this reason, the upper limit of the C content is set to 1.5%, while if the C content is less than 0.3%, the sigma phase precipitates during use at high temperatures, resulting in a marked decrease in ductility. Therefore, the lower limit is set to 0.3%.
Si:2％を超えて３％以下 Si:は耐浸炭性を向上させる重要な元素である。また、
後記するようにAlも耐浸炭性を向上させる重要な元素で
ある。本発明者は、1100℃を超える温度での耐浸炭性を
確保するため、特にAlとSiとの関係について鋭意研究し
た結果、Siの含有量が２％以下のときは、Al含有による
耐浸炭性向上効果はあまり期待できないことを見出し
た。このため、Siは少なくとも２％を超えて含有させる
必要がある。しかし、Siの含有量を多くすると、材料の
劣化が進み、クリープ破断強度が低下して溶接性が損な
われるので、その上限は３％に規定する。Si: more than 2% and 3% or less Si: is an important element that improves carburization resistance. Also,
As will be described later, Al is also an important element that improves carburization resistance. In order to secure the carburization resistance at a temperature exceeding 1100 ° C., the present inventor has conducted earnest research on the relationship between Al and Si. As a result, when the Si content is 2% or less, the carburization resistance due to Al content is high. It was found that the effect of improving the sex could not be expected so much. Therefore, it is necessary to contain Si in an amount of at least 2%. However, if the Si content is increased, the deterioration of the material proceeds, the creep rupture strength decreases, and the weldability is impaired. Therefore, the upper limit is set to 3%.
Mn:2％以下 Mnは脱酸、脱硫元素として添加される。しかし、あまり
に多く含有すると、高温クリープ破断強度や耐浸炭性の
低下を招来する。このため、上限は２％に規定する。Mn: 2% or less Mn is added as a deoxidizing and desulfurizing element. However, if the content is too large, the high temperature creep rupture strength and the carburization resistance are deteriorated. Therefore, the upper limit is set to 2%.
Cr:20〜30％ Crは高温強度、耐酸化性、耐浸炭性等の改善に有効な元
素である。1100℃以上の高温域においてこれらの特性を
確保するためには、少なくとも20％含有させる必要があ
る。この効果は含有量の増加に伴って増大するが、あま
りに多く含有すると鋳造、凝固過程で割れが生じやすく
なり、高温使用に伴う炭化物の過剰析出によって、延性
の低下を招く。このため、上限は30％に規定する。Cr: 20-30% Cr is an element effective for improving high temperature strength, oxidation resistance, carburization resistance and the like. In order to secure these characteristics in a high temperature range of 1100 ° C or higher, it is necessary to contain at least 20%. This effect increases as the content increases, but if the content is too large, cracking easily occurs during the casting and solidification processes, and excessive precipitation of carbides due to use at high temperature leads to a decrease in ductility. Therefore, the upper limit is set to 30%.
Ni:25〜40％ NiはCr、Mn等の元素と共に安定なオーステナイト基地を
形成し、高温強度及び耐酸化性を高めるとともに、耐浸
炭性の向上に寄与する。特に1100℃の高温域における良
好な耐浸炭性を確保するには、25％以上の添加を必要と
する。しかし、40％を超えて含有しても含有量に対応す
る効果は得られず、経済的でない。このため、40％を上
限とする。Ni: 25-40% Ni forms a stable austenite matrix together with elements such as Cr and Mn, enhances high temperature strength and oxidation resistance and contributes to improvement of carburization resistance. In particular, in order to secure good carburization resistance in the high temperature range of 1100 ° C, it is necessary to add 25% or more. However, even if the content exceeds 40%, the effect corresponding to the content cannot be obtained, which is not economical. Therefore, the upper limit is 40%.
Al:0.2〜2.0％ Alは、高温における耐酸化性の改善に効果があるだけで
なく、前述したように、Si含有量が２％を超えるとき、
Siとの相乗効果によって耐浸炭性の向上に飛躍的に寄与
する。1100℃以上の高温使用条件下での耐浸炭性改善効
果を十分発揮させるためには、少なくとも0.2％含有さ
せる必要がある。耐浸炭性改善効果は、添加量の増加に
伴って大きくなるが、2.0％を超えて添加してもその効
果はほぼ飽和する。また、Alの含有量の増加とともに、
鋳造凝固時や溶接時に割れが発生しやすくなり、高温使
用時に延性の劣化を招く。このため、２％を上限にす
る。Al: 0.2-2.0% Al not only has the effect of improving the oxidation resistance at high temperatures, but as described above, when the Si content exceeds 2%,
A synergistic effect with Si contributes dramatically to the improvement of carburization resistance. In order to fully exert the effect of improving carburization resistance under high temperature use conditions of 1100 ° C or higher, it is necessary to contain at least 0.2%. The effect of improving carburization resistance increases as the amount of addition increases, but even if added over 2.0%, the effect is almost saturated. Also, as the content of Al increases,
Cracking is likely to occur during solidification of casting or welding, which leads to deterioration of ductility when used at high temperatures. Therefore, the upper limit is 2%.
Nb:0.2〜2.0％ Nbはクリープ破断強度を高める効果を有する。Si含有量
が多く、かつAlを添加した本発明の耐熱鋼にあっては、
高温強度、特にクリープ破断強度を低下させる不都合が
あるため、すぐれた耐浸炭性を確保し、かつ大きいクリ
ープ破断強度を維持するためには不可欠の元素である。
この効果を得るために、少なくとも0.2％以上含有する
必要がある。但し、あまりに多く含有すると、逆にクリ
ープ破断強度の低下を招くため、2.0％を上限とする。Nb: 0.2-2.0% Nb has the effect of increasing the creep rupture strength. In the heat-resistant steel of the present invention having a high Si content and having Al added,
It has an inconvenience of lowering high-temperature strength, particularly creep rupture strength, and is therefore an essential element for ensuring excellent carburization resistance and maintaining large creep rupture strength.
In order to obtain this effect, it is necessary to contain at least 0.2% or more. However, if it is contained too much, the creep rupture strength is lowered, so 2.0% is made the upper limit.
W:0.2〜2.0％ Ｗはクリープ破断強度の向上と、高温におけるクリープ
変形能の向上に寄与する。含有量が0.2％に満たないと
高温でのクリープ変形能の向上効果にあまり寄与しな
い。一方、2.0％を超えるとクリープ破断強度が却って
低下する。このため、含有量は0.2〜2.0％とする。W: 0.2 to 2.0% W contributes to the improvement of creep rupture strength and the creep deformability at high temperature. If the content is less than 0.2%, it does not contribute much to the effect of improving creep deformability at high temperatures. On the other hand, if it exceeds 2.0%, the creep rupture strength rather decreases. Therefore, the content is set to 0.2 to 2.0%.
Ti:0.01〜0.3％ TiはNbと同様にクリープ破断強度を高める効果を有する
ため、さらに大きいクリープ破断強度を必要とする場合
に添加される。Tiによる所望の効果を得るためには、少
なくとも0.01％以上含有させる必要がある。しかし、あ
まり多く含有すると、逆にクリープ破断強度の低下を招
くと共に、鋳造割れを発生する。このため、上限は0.3
％に規定する。Ti: 0.01 to 0.3% Ti has the same effect of increasing the creep rupture strength as Nb, so it is added when a higher creep rupture strength is required. In order to obtain the desired effect of Ti, it is necessary to contain at least 0.01% or more. However, if the content is too large, on the contrary, the creep rupture strength is lowered and casting cracks occur. Therefore, the upper limit is 0.3
Specify as%.
本発明の耐熱鋼は、前述した合金成分を含み、残部実質
的にFeからなる。なお、鋼の溶製時に不可避的に含有す
るＰ、Ｓその他の不純物であっても、この種の鋼材に通
常許容される範囲であれば存在しても構わない。The heat-resisting steel of the present invention contains the alloy components described above, and the balance is substantially Fe. It should be noted that P, S, and other impurities that are inevitably contained during the melting of steel may be present as long as they are in the range normally allowed for this type of steel material.
次に実施例を挙げて本発明の耐熱鋼における耐浸炭性及
びクリープ破断強度の向上効果を明らかにする。Next, examples are given to clarify the effects of improving the carburization resistance and creep rupture strength of the heat-resistant steel of the present invention.
［実施例］ 高周波溶解炉にて各種成分の合金を溶製し、遠心鋳造に
て管体（外径130mm×内径90mm×長さ500ミリ）を製造し
た。この遠心力鋳造管から機械加工によって供試片（直
径12mm×長さ60mm）を採取した。各供試片の合金成分を
第１表に示す。[Examples] Alloys of various components were melted in a high frequency melting furnace, and a tubular body (outer diameter 130 mm x inner diameter 90 mm x length 500 mm) was manufactured by centrifugal casting. Specimens (diameter 12 mm x length 60 mm) were collected from this centrifugal casting tube by machining. Table 1 shows the alloy composition of each test piece.
まず、これらの供試片について、固体浸炭試験を行なっ
た。浸炭試験は、固体浸炭剤（テグサKG30、BaCO3含
有）を用いて行ない、温度1150℃、500時間保持後の浸
炭量を測定した。浸炭後、供試片の外表面より4mm深さ
に達するまで旋盤加工により0.5mmピッチにてダライ粉
を採取し、各ピッチのＣ（カーボン）分析を行ない、各
ピッチ毎のＣ増加量の合計値を第２表に示した。First, a solid carburization test was performed on these test pieces. The carburization test was carried out using a solid carburizing agent (Tegusa KG30, containing BaCO 3 ) and the amount of carburization was measured after the temperature was kept at 1150 ° C. for 500 hours. After carburizing, the Dalai powder was sampled at a pitch of 0.5 mm by lathing until it reached a depth of 4 mm from the outer surface of the test piece, and C (carbon) analysis was performed for each pitch, and the total amount of C increase for each pitch The values are shown in Table 2.
更に、各供試片について、1093℃×1.1Kg/mm2の条件下
でクリープ破断試験を行ない、各供試片の破断時間を第
２表に示した。Further, a creep rupture test was performed on each test piece under the condition of 1093 ° C. × 1.1 Kg / mm 2 , and the breaking time of each test piece is shown in Table 2.
比較材の供試片No.13〜19の結果について考察する。供
試片No.13とNo.15はSiが２％に満たない合金であり、N
o.13についてはAlを含有せず、No.15はAlを含有してい
る。No.14とNo.16〜19は、Si含有量が２％を超えている
合金である。その中で、No.14はAlを含まず、No.19はAl
の含有量が0.2％に満たない合金、No.16〜18は0.2％以
上のAlを含む合金である。 The results of the test pieces Nos. 13 to 19 of the comparative material will be considered. Specimen No. 13 and No. 15 are alloys with Si less than 2%, and N
No. 15 does not contain Al, and No. 15 contains Al. No. 14 and Nos. 16 to 19 are alloys in which the Si content exceeds 2%. Among them, No.14 does not contain Al and No.19 is Al.
No. 16 to 18 are alloys containing less than 0.2%, and Nos. 16 to 18 are alloys containing 0.2% or more of Al.
この結果から明らかなように、供試片No.16〜18は、No.
13〜15に比べてＣの増加量は著しく減少している。即
ち、耐浸炭性にすぐれている。なお、供試片No.19は、A
l含有量が少ないため、耐浸炭性に関し、顕著な向上効
果は認められなかった。As is clear from this result, the test pieces Nos. 16 to 18 are Nos.
The amount of increase of C is remarkably decreased as compared with 13 to 15. That is, it has excellent carburization resistance. Specimen No. 19 is A
Since the content of l was small, no significant improvement effect on carburization resistance was observed.
一方、Si含有量が２％を超える合金にAlを含有させれ
ば、クリープ破断強度が低下する傾向がある。特に供試
片No.17のように、高Si、高いAl材料の場合、クリープ
破断強度の低下は著しい。On the other hand, when Al is contained in an alloy having a Si content of more than 2%, the creep rupture strength tends to decrease. In particular, in the case of a high Si and high Al material such as Specimen No. 17, the creep rupture strength is significantly reduced.
これに対し、供試片No.1〜12については、Si含有量が２
％を超える材料に適量のAlを含有させ、更に適量のNb及
びＷ、又はNb、Ｗ及びTiを含有させたから、すぐれた耐
浸炭性を維持しつつ、かつ高いクリープ破断強度を具備
している。このように、耐浸炭性とクリープ破断強度
は、相反する特性であるに拘わらず、本発明の耐熱鋼
は、両者ともすぐれた特性を有している。On the other hand, for the test pieces Nos. 1 to 12, the Si content is 2
% Of the material contains an appropriate amount of Al and further contains an appropriate amount of Nb and W, or Nb, W and Ti, so that it has excellent carburization resistance and high creep rupture strength. . As described above, the carburization resistance and the creep rupture strength are contradictory properties, but the heat-resistant steel of the present invention has excellent properties.
［発明の効果］ 本発明の耐熱鋼は、1100℃を超える高温域における使用
において、すぐれた耐浸炭性と、高いクリープ破断強度
を具備している。従って、本発明の耐熱鋼は、石油化学
工業における炭化水素の反応管等の材料として好適であ
る。[Effects of the Invention] The heat-resistant steel of the present invention has excellent carburization resistance and high creep rupture strength when used in a high temperature range exceeding 1100 ° C. Therefore, the heat resistant steel of the present invention is suitable as a material for a reaction tube for hydrocarbons in the petrochemical industry.
Claims (2)
て３％以下、Mn:2％以下、Cr:20〜30％、Ni:25〜40％、
Al:0.2〜2.0％、Nb:0.2〜2.0％、W:0.2〜2.0％及び残部
実質的にFeからなり、耐浸炭性及びクリープ破断強度に
すぐれる耐熱鋼。1. In weight%, C: 0.3 to 1.5%, Si: more than 2% and 3% or less, Mn: 2% or less, Cr: 20 to 30%, Ni: 25 to 40%,
A heat-resistant steel with excellent carburization resistance and creep rupture strength, consisting of Al: 0.2-2.0%, Nb: 0.2-2.0%, W: 0.2-2.0% and the balance essentially Fe.
て３％以下、Mn:2％以下、Cr:20〜30％、Ni:25〜40％、
Al:0.2〜2.0％、Nb:0.2〜2.0％、W:0.2〜2.0％、Ti:0.0
1〜0.3％及び残部実質的にFeからなり、耐浸炭性及びク
リープ破断強度にすぐれる耐熱鋼。2. In% by weight, C: 0.3 to 1.5%, Si: more than 2% and 3% or less, Mn: 2% or less, Cr: 20 to 30%, Ni: 25 to 40%,
Al: 0.2-2.0%, Nb: 0.2-2.0%, W: 0.2-2.0%, Ti: 0.0
Heat-resistant steel with excellent carburizing resistance and creep rupture strength, consisting of 1 to 0.3% and the balance Fe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33627790A JPH07103448B2 (en) | 1990-11-28 | 1990-11-28 | Heat-resistant steel with excellent carburization resistance and creep rupture strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33627790A JPH07103448B2 (en) | 1990-11-28 | 1990-11-28 | Heat-resistant steel with excellent carburization resistance and creep rupture strength |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04198457A JPH04198457A (en) | 1992-07-17 |
| JPH07103448B2 true JPH07103448B2 (en) | 1995-11-08 |
Family
ID=18297449
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33627790A Expired - Lifetime JPH07103448B2 (en) | 1990-11-28 | 1990-11-28 | Heat-resistant steel with excellent carburization resistance and creep rupture strength |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07103448B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108977718A (en) * | 2018-07-25 | 2018-12-11 | 江苏永达电源股份有限公司 | A kind of alloy that creep-resistant property is promoted |
-
1990
- 1990-11-28 JP JP33627790A patent/JPH07103448B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108977718A (en) * | 2018-07-25 | 2018-12-11 | 江苏永达电源股份有限公司 | A kind of alloy that creep-resistant property is promoted |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04198457A (en) | 1992-07-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0548405B1 (en) | Heat-resistant alloy having high creep rupture strength under high-temperature low-stress conditions and excellent resistance to carburization | |
| JPS6344814B2 (en) | ||
| JPH072981B2 (en) | Heat resistant alloy | |
| JPS6142781B2 (en) | ||
| JP3895089B2 (en) | Heat resistant alloy with excellent carburization and metal dusting resistance | |
| JPH07103448B2 (en) | Heat-resistant steel with excellent carburization resistance and creep rupture strength | |
| JPH07103449B2 (en) | Heat-resistant steel with excellent carburization resistance and creep rupture strength | |
| JP2000256803A (en) | Austenitic stainless steel excellent in high temperature strength and ductility | |
| JP3921943B2 (en) | Ni-base heat-resistant alloy | |
| JPH04502938A (en) | Iron, nickel, chromium base alloy | |
| JPH01152245A (en) | Heat-resistant alloy having excellent carburizing resistance | |
| JPS6138256B2 (en) | ||
| JPS596910B2 (en) | heat resistant cast steel | |
| JPS5935425B2 (en) | heat resistant cast steel | |
| JPH05195138A (en) | Heat resistant alloy having excellent carburization resistance and high creep rupture strength under conditions of high temperature and low stress | |
| JPH07166290A (en) | Heat resistant alloy excellent in carburization resistance and oxidation resistance | |
| JPH07258780A (en) | Heat resistant alloy excellent in carburization resistance | |
| JPH0987787A (en) | Heat resistant alloy excellent in oxidation resistance, carburization resistance, high temperature creep fracture strength and ductility after aging | |
| JPS596909B2 (en) | heat resistant cast steel | |
| JPH07258783A (en) | Heat resistant alloy excellent in carburization resistance | |
| JPS5935984B2 (en) | heat resistant cast steel | |
| JPS5919978B2 (en) | Malleable Ni-based super heat-resistant alloy | |
| JPS625224B2 (en) | ||
| JPS5935429B2 (en) | heat resistant cast steel | |
| JPH07233446A (en) | Carburizing resistant and heat resistant cast alloy steel |