JPH07103351A - Valve seat of fluid valve including sea water and chloride - Google Patents
Valve seat of fluid valve including sea water and chlorideInfo
- Publication number
- JPH07103351A JPH07103351A JP24462493A JP24462493A JPH07103351A JP H07103351 A JPH07103351 A JP H07103351A JP 24462493 A JP24462493 A JP 24462493A JP 24462493 A JP24462493 A JP 24462493A JP H07103351 A JPH07103351 A JP H07103351A
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- JP
- Japan
- Prior art keywords
- valve seat
- base material
- alloy
- valve
- chloride
- 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.)
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、海水または塩化物を含
有する流体で使用される弁の弁座に関する。特に、オー
ステナイト系ステンレス鋼製、またはＣｏ基あるいはＮ
ｉ基製の弁、例えば、逆止弁、球型弁等の弁座に関する
ものである。FIELD OF THE INVENTION The present invention relates to valve seats for valves used with seawater or chloride-containing fluids. In particular, made of austenitic stainless steel, Co-based or N
The present invention relates to a valve seat made of an i-based valve, such as a check valve and a ball valve.
【０００２】[0002]
【従来の技術】従来、前記したような弁の弁座には、図
３（ａ）に示すように、その材料として、Ｃ：１〜３
％、Ｃｒ：２５〜３２％、及びＷ：２〜１７％を含有す
るＣｏ基合金が使用され、弁座材（５）として、弁の弁
座部基材（４）に、ガスまたは電弧で直接溶接されて使
用されていた。このため、弁座に隣接する、Ｃ：０.０
８％以下であるステンレス鋼弁あるいはＣ：０.１５％
以下であるＣｏ基やＮｉ基弁の基材には、以下の原因に
よって、炭素の富化が生じていた。 1） ガス溶接の場合には、溶接に使用するアセチレン
焔からの浸炭。 2） 電弧溶接の場合には、高炭素の弁座用合金が、基
材と融合することによる、炭素量の増加。 3） また、これらの弁は、弁座基材へ上記合金を溶接
した後、応力除去と熱影響部の炭化物を固溶するため
に、１０００℃〜１１５０℃で溶体化処理が行われる
が、合金の炭素量が高いために溶接合金から基材へ炭素
が移行する。2. Description of the Related Art Conventionally, as shown in FIG.
%, Cr: 25 to 32%, and W: 2 to 17%, a Co-based alloy is used. As a valve seat material (5), a valve seat base material (4) of a valve is provided by gas or electric arc. It was directly welded and used. Therefore, C: 0.0 adjacent to the valve seat
8% or less stainless steel valve or C: 0.15%
The following Co-based and Ni-based valve base materials were enriched with carbon due to the following causes. 1) In the case of gas welding, carburization from acetylene flame used for welding. 2) In the case of electric arc welding, the amount of carbon increases due to the fusion of the high carbon valve seat alloy with the base material. 3) In addition, these valves are subjected to solution treatment at 1000 ° C. to 1150 ° C. in order to remove stress and solidify the carbide in the heat-affected zone after welding the alloy to the valve seat base material. Due to the high carbon content of the alloy, carbon is transferred from the weld alloy to the substrate.
【０００３】このようにして、炭素富化の生じた弁座隣
接部の基材の結晶粒界及び粒内には、Ｃｒを主体とする
炭化物が、溶体化処理後も残留していた。このため、こ
のような弁座を有する弁を、海水弁あるいは塩化物を含
有する流体の化学工業用弁として使用すると、弁座隣接
部に粒界腐食を主体とする腐食や粒内割れを伴う応力腐
食割れが生じ、弁座下部に割れ（６）が生じたり、場合
によっては、弁座が剥離することがあった。弁座下部の
割れ（６）の部分を拡大して模式的に示しせば、図３
（ｂ）の通りであり、（７）は基材の結晶粒界に析出し
た炭化物、（８）は粒内に析出した炭化物を示す。In this way, carbides mainly containing Cr remained in the grain boundaries and grains of the base material adjacent to the valve seat where carbon enrichment occurred even after the solution treatment. For this reason, when a valve having such a valve seat is used as a seawater valve or a valve for a chemical industry of a fluid containing chloride, corrosion or intragranular cracking mainly due to intergranular corrosion occurs in the valve seat adjacent portion. In some cases, stress corrosion cracking occurred and cracks (6) occurred in the lower portion of the valve seat, and in some cases, the valve seat peeled off. If the cracked portion (6) under the valve seat is enlarged and schematically shown in FIG.
As in (b), (7) shows carbides precipitated at the crystal grain boundaries of the base material, and (8) shows carbides precipitated in the grains.
【０００４】特に、オーステナイト系ステンレス鋼弁で
は、基材であるステンレス鋼の熱膨脹係数が、１７×１
０-6／℃と大きく、こに対して、上記Ｃｏ基合金の熱膨
脹係数が１４×１０-6／℃と小さく、また、その強度が
９０Kgf／mm2と大きいために、弁座の溶接後あるいは溶
接後の溶体化処理時の冷却過程で、基材の弁座隣接部
に、この鋼の耐力に相当する、約３０Kgf／mm2程度の引
張残留応力が生じ、この応力が弁座隣接部の腐食を促進
するという問題があった。Particularly, in the austenitic stainless steel valve, the coefficient of thermal expansion of the stainless steel as the base material is 17 × 1.
0 -6 / ° C. and greater, with respect to this, the thermal expansion coefficient of the Co-based alloy as small as 14 × 10 -6 / ℃, also because its strength is as large as 90 kgf / mm 2, after welding of the valve seat Alternatively, in the cooling process during solution treatment after welding, a tensile residual stress of about 30 Kgf / mm 2 corresponding to the proof stress of this steel occurs in the valve seat adjacent part of the base material, and this stress occurs in the valve seat adjacent part. There was a problem of accelerating the corrosion of.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、海水や塩化
物を含有する流体に使用される弁の弁座隣接部の基材の
粒界腐食や応力腐食割れを防止することを目的としてな
されたものである。SUMMARY OF THE INVENTION The present invention has been made for the purpose of preventing intergranular corrosion and stress corrosion cracking of a base material adjacent to a valve seat of a valve used for a fluid containing seawater or chloride. It is a thing.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、上記課題
の解決について鋭意検討を行った結果、特定組成の合金
を弁座基材に上下二層溶接することにより、弁座隣接部
の基材の粒界腐食や応力腐食割れを防止することが可能
であることを見いだし、本発明を完成するに至った。即
ち、本発明によれば、弁座の下地盛金として、Ｃ：０.
１５％以下、Ｃｒ：１４〜２５％およびＮｉ：４５〜７
５％、場合によりさらにＡｌ：０.８〜２.０％を含有
し、残部は実質的にＦｅからなる合金が弁座基材に溶接
され、その上層に、Ｃ：０.１５％以下、Ｃｒ：２０〜
３０％、Ｓｉ：３〜７％、Ｆｅ：３〜８％およびＷ：１
〜３％を含有し、残部は実質的にＮｉよりなる合金が溶
接されていることを特徴とする、海水及び塩化物を含有
する流体用弁の弁座が提供される。Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the inventors of the present invention have found that the alloy of a specific composition is welded to a valve seat base material in two upper and lower layers to form The inventors have found that it is possible to prevent intergranular corrosion and stress corrosion cracking of the base material, and have completed the present invention. That is, according to the present invention, the base metal of the valve seat is C: 0.
15% or less, Cr: 14 to 25% and Ni: 45 to 7
5%, optionally further containing Al: 0.8-2.0%, the balance being an alloy consisting essentially of Fe, welded to the valve seat substrate, with C: 0.15% or less on the upper layer, Cr: 20-
30%, Si: 3-7%, Fe: 3-8% and W: 1
Provided is a valve seat for a fluid valve containing seawater and chloride, characterized in that an alloy containing ˜3% and the balance consisting essentially of Ni is welded.
【０００７】本発明の弁座においては、上記したように
特定組成の合金を下地盛金として基材に溶接することが
重要である。該合金中のＮｉ含有量は基材溶接部の応力
腐食に大きな影響を与える。例えば、基材がオーステナ
イト系ステンレスで構成されている場合には、Ｎｉの含
有量が多くなる程、応力腐食割れに対する耐食性が良好
となるが、Ｎｉ含有量が４５％以上であれば、塩化物を
含有する流体の応力腐食割れに対して免疫的となる。し
かし、Ｎｉ含有量が７５％を越えると高温高圧の純水及
び塩化物に対する応力腐食に対する免疫性が低下するの
で好ましくない。In the valve seat of the present invention, as described above, it is important to weld the alloy of the specific composition to the base material as the base metal. The Ni content in the alloy has a great influence on the stress corrosion of the base material weld. For example, when the base material is made of austenitic stainless steel, the higher the Ni content, the better the corrosion resistance to stress corrosion cracking, but if the Ni content is 45% or more, chloride Is immune to stress corrosion cracking of fluids containing. However, when the Ni content exceeds 75%, the immunity to stress corrosion against pure water and chloride under high temperature and high pressure is lowered, which is not preferable.
【０００８】下地盛の合金におけるＣｒ含有量は１４〜
２５％である。Ｃｒ含有量をこの範囲に維持することに
より、耐食性の維持および応力腐食ワレを防止すること
ができる。該合金にＡｌを０.８〜２.０％を含有させる
ことができ、その結果合金中の耐応力腐食性に有害な窒
素が固定され、耐応力腐食性を間接的に向上させること
ができる。The Cr content in the underlaying alloy is 14 to
25%. By maintaining the Cr content within this range, it is possible to maintain corrosion resistance and prevent stress corrosion cracking. The alloy can contain 0.8 to 2.0% of Al, and as a result, nitrogen which is harmful to the stress corrosion resistance in the alloy is fixed, and the stress corrosion resistance can be indirectly improved. .
【０００９】上記下地盛金の上層に溶接される合金は、
Ｃ：０.１５％以下、Ｃｒ：２０〜３０％、Ｓｉ：３〜
７％、Ｆｅ：３〜８％およびＷ：１〜３％を含有し、残
部は実質的にＮｉよりなるものである。このような特定
組成の合金を使用することにより、下地の耐食性、耐応
力腐食性、強度等に優れた弁座とすることができる。The alloy welded to the upper layer of the base metal is
C: 0.15% or less, Cr: 20-30%, Si: 3-
It contains 7%, Fe: 3 to 8% and W: 1 to 3%, and the balance substantially consists of Ni. By using the alloy having such a specific composition, a valve seat having excellent corrosion resistance, stress corrosion resistance, strength and the like of the base can be obtained.
【００１０】下地および上層の合金の基材への溶接は、
電弧溶接、例えばＴＩＧ溶接またはＰＴＡ（プラズマ・
トランスファ・アーク）溶接等により行うことができ
る。下地層および上層の厚さは、通常、１〜４ｍｍ程
度、好ましくは２ｍｍ程度である。Welding of the base and top alloys to the substrate is
Electric arc welding, eg TIG welding or PTA (plasma
Transfer / arc) welding or the like. The thickness of the underlayer and the upper layer is usually about 1 to 4 mm, preferably about 2 mm.
【００１１】本発明による弁座は基材に下地盛金および
上層盛金が設けられているので、下記のような効果を有
している。下地盛金の効果として、 1） 弁座の下地盛をする時点で、合金と基材の融合部
の炭素量を実用上十分に低減できる。 2） 本合金自体は、Ｎｉ：４５〜７５％を含有してい
るため、塩化物を含有する流体中での応力腐食に対して
免疫的である。 3） Ｎｉ：４５〜７５％を含有する下地盛合金が、基
材であるオーステナイト系ステンレス鋼と溶接されるこ
とによって生じる融合部の熱膨脹係数は、ほぼ、ステン
レス鋼と同等となって、基材側の残留応力を低減する。
例えば、溶接によって、Ｎｉ：３０〜３５％となった融
合部の熱膨脹係数は、１７×１０-6／℃程度となる。ま
た、融合部は、基材よりもＮｉが多いために、耐応力腐
食性は基材より優れている。The valve seat according to the present invention has the following effects because the base deposit and the upper deposit are provided on the base material. As the effect of the base metal deposit, 1) the carbon content in the fusion portion of the alloy and the base material can be sufficiently reduced practically at the time of base metal coating of the valve seat. 2) Since the present alloy itself contains Ni: 45 to 75%, it is immune to stress corrosion in a chloride-containing fluid. 3) The thermal expansion coefficient of the fused portion produced by welding the underlaying alloy containing Ni: 45 to 75% with the austenitic stainless steel that is the base material is almost the same as that of stainless steel, and the base material Side residual stress is reduced.
For example, the thermal expansion coefficient of the fused portion where Ni: 30 to 35% is obtained by welding is about 17 × 10 −6 / ° C. Moreover, since the fused portion has more Ni than the base material, the stress corrosion resistance is superior to the base material.
【００１２】また、上層盛金の効果として、 1） 弁座の上層に溶接する合金は、Ｎｉ：５２〜７３
％程度を含有しているので、下地盛金と同様に、応力腐
食に対して免疫的である。 2） Ｃ量を０.１５％以下としているので、下地盛金の
耐食性を害しない。 3） Ｓｉ量を３〜７％としているので、耐応力腐食性
は、Ｎｉの効果に加えて、更に、向上している。また、
Ｓｉの添加によって、上層盛金の硬さは３００〜４００
ＨＢの硬さとなり、弁座の硬さとして実用上十分な硬さ
を有している。 4） 盛金が、ホウ素を含有していないことから、高温
高圧水の中における応力腐食割れに対しても免疫性があ
る。 5） 上層に溶接する合金の熱膨脹係数は１３×１０-6
／℃程度となり、一方下地盛の合金の熱膨脹係数は１５
×１０-6／℃程度であるために、上層の溶接や熱処理時
に下地盛部に引張残留応力が生じるが、下地盛部と基材
との融合部の熱膨脹係数が基材と同等であり、上層溶接
部が基材と離れているため、基材には引張残留応力は生
じない。 このため、基材の応力腐食は、有効に防止できる。Further, as an effect of the upper layer deposit, 1) The alloy to be welded to the upper layer of the valve seat is Ni: 52-73.
%, It is immune to stress corrosion as well as base metal deposit. 2) Since the C content is 0.15% or less, it does not impair the corrosion resistance of the base deposit. 3) Since the amount of Si is 3 to 7%, the stress corrosion resistance is further improved in addition to the effect of Ni. Also,
The hardness of the upper layer metal deposit is 300 to 400 due to the addition of Si.
It has a hardness of HB, and has a practically sufficient hardness as the hardness of the valve seat. 4) Since Sorikin does not contain boron, it is immune to stress corrosion cracking in high temperature and high pressure water. 5) The coefficient of thermal expansion of the alloy welded to the upper layer is 13 × 10 -6
/ ° C, while the thermal expansion coefficient of the base alloy is 15
Since it is about × 10 -6 / ° C, a tensile residual stress is generated in the underlaying portion during welding or heat treatment of the upper layer, but the thermal expansion coefficient of the fused portion between the underlaying portion and the base material is equal to that of the base material, Since the upper layer weld is separated from the base material, no tensile residual stress occurs in the base material. Therefore, stress corrosion of the base material can be effectively prevented.
【００１３】本発明の弁座は以上のような効果を有する
ので、弁座隣接部の基材及び弁座自体の応力腐食割れの
防止に有効であり、海水及びその他の塩化物を含む腐食
流体で使用されるステンレス鋼及びＣｏ基あるいはＮｉ
基弁の弁座に有効に適用できる。Since the valve seat of the present invention has the above effects, it is effective in preventing stress corrosion cracking of the base material adjacent to the valve seat and the valve seat itself, and the corrosive fluid containing seawater and other chlorides. Used in stainless steel and Co-based or Ni
It can be effectively applied to the base valve seat.
【００１４】[0014]
【実施例】図１によりは、本発明の弁座の具体例を説明
する。図１は本発明の弁座の断面図を示すものである。
図２に示したような逆止弁において、弁座基材（４）
に、下地盛金（１）として、Ｃ：０.０２％、Ｃｒ：２
３％およびＮｉ：６１％を含有し、残部は実質的にＦｅ
からなる合金を２ｍｍの厚さにティグ溶接した。次い
で、その上に、上層盛金（２）としてＣ：０.０２％、
Ｃｒ：２５％、Ｓｉ：５％、Ｆｅ：６％およびＷ：１.
５％を含有し、残部は実質的にＮｉよりなる合金を２ｍ
ｍの厚さに溶接した後、１０７０℃で溶体化処理を行っ
た。このようにして製造された逆止弁について、ＪＩＳ
Ｇ０５７５に規定する「ステンレス鋼の硫酸・硫酸銅
腐食試験」を行った。試験時間はＪＩＳの規定の１６時
間より苛酷な１５０時間を採用した。その結果、内盛隣
接部に僅かに結晶粒界が現れたのみで、割れの発生等は
認められなかった。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of the valve seat of the present invention will be described with reference to FIG. FIG. 1 shows a sectional view of the valve seat of the present invention.
In the check valve as shown in FIG. 2, the valve seat base material (4)
As the base deposit (1), C: 0.02%, Cr: 2
3% and Ni: 61%, the balance being essentially Fe
Was alloyed by TIG welding to a thickness of 2 mm. Then, C: 0.02% as the upper layer gold (2),
Cr: 25%, Si: 5%, Fe: 6% and W: 1.
2m of an alloy containing 5% and the balance being substantially Ni.
After welding to a thickness of m, solution treatment was performed at 1070 ° C. Regarding the check valve manufactured in this way, JIS
The “sulfuric acid / copper sulfate corrosion test of stainless steel” specified in G0575 was conducted. The test time was 150 hours, which was more severe than the JIS standard of 16 hours. As a result, only a few crystal grain boundaries appeared in the area adjacent to the internal deposits, and no cracking was observed.
【００１５】次に、下地盛材としてＣ：０.０２％、Ｃ
ｒ：２３％、Ｎｉ：６１％およびＡｌ：１.５％を含有
し、残部は実質的にＦｅからなる合金を使用した以外
は、上記と同様にして本発明の弁座を製造した。その評
価結果も上記と同様であった。Next, C: 0.02%, C
A valve seat of the present invention was manufactured in the same manner as described above, except that an alloy containing r: 23%, Ni: 61% and Al: 1.5% and the balance being substantially Fe was used. The evaluation results were also the same as above.
【図１】本発明の弁座の断面図である。FIG. 1 is a sectional view of a valve seat of the present invention.
【図２】逆止弁の側面図であって、本発明が適用される
弁座位置を示すものである。FIG. 2 is a side view of the check valve, showing a valve seat position to which the present invention is applied.
【図３】従来の弁座の断面図（ａ）、およびその一部
（破線円）を拡大した模式図（ｂ）である。FIG. 3 is a cross-sectional view (a) of a conventional valve seat, and a schematic view (b) in which a part (broken line circle) is enlarged.
１ 弁座の下地盛金 ２ 弁座の上層盛金 ３ 下地盛金と基材との融合部 ４ 弁座基材 ５ 高炭素含有弁座材 ６ 弁座隣接部の割れ ７ 基材の結晶粒界に析出した炭化物 ８ 粒内に析出した炭化物 1 Base sheet base metal for valve seat 2 Upper layer base metal for valve seat 3 Fusion part between base metal base and base material 4 Valve seat base material 5 Valve seat material with high carbon content 6 Crack in adjacent part of valve seat 7 Crystal grains of base material Carbide precipitated in the boundary 8 Carbide precipitated in the grain
Claims (2)
以下、Ｃｒ：１４〜２５％およびＮｉ：４５〜７５％を
含有し、残部は実質的にＦｅからなる合金が弁座基材に
溶接され、その上層に、Ｃ：０.１５％以下、Ｃｒ：２
０〜３０％、Ｓｉ：３〜７％、Ｆｅ：３〜８％および
Ｗ：１〜３％を含有し、残部は実質的にＮｉよりなる合
金が溶接されていることを特徴とする、海水及び塩化物
を含有する流体用弁の弁座。1. As a base metal for valve seat, C: 0.15%
Hereinafter, an alloy containing Cr: 14 to 25% and Ni: 45 to 75%, and the balance being substantially Fe is welded to the valve seat base material, and C: 0.15% or less, Cr : 2
Seawater, characterized in that an alloy containing 0 to 30%, Si: 3 to 7%, Fe: 3 to 8% and W: 1 to 3% and the balance being substantially Ni is welded. And a valve seat of a fluid valve containing chloride.
以下、Ｃｒ：１４〜２５％、Ｎｉ：４５〜７５％および
Ａｌ：０.８〜２.０％を含有し、残部は実質的にＦｅか
らなる合金が弁座基材に溶接され、その上層に、Ｃ：
０.１５％以下、Ｃｒ：２０〜３０％、Ｓｉ：３〜７
％、Ｆｅ：３〜８％およびＷ：１〜３％を含有し、残部
は実質的にＮｉよりなる合金が溶接されていることを特
徴とする、海水及び塩化物を含有する流体用弁の弁座。2. As a base metal for valve seat, C: 0.15%
Hereinafter, an alloy containing Cr: 14 to 25%, Ni: 45 to 75% and Al: 0.8 to 2.0%, and the balance being substantially Fe is welded to the valve seat base material to form an upper layer thereof. And C:
0.15% or less, Cr: 20-30%, Si: 3-7
%, Fe: 3-8% and W: 1-3%, the balance being a welded alloy consisting essentially of Ni, of a valve for a fluid containing seawater and chloride. valve seat.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5244624A JP2637039B2 (en) | 1993-09-30 | 1993-09-30 | Valve seats for fluids containing seawater and chloride |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5244624A JP2637039B2 (en) | 1993-09-30 | 1993-09-30 | Valve seats for fluids containing seawater and chloride |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07103351A true JPH07103351A (en) | 1995-04-18 |
| JP2637039B2 JP2637039B2 (en) | 1997-08-06 |
Family
ID=17121522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5244624A Expired - Fee Related JP2637039B2 (en) | 1993-09-30 | 1993-09-30 | Valve seats for fluids containing seawater and chloride |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2637039B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004019918A (en) * | 2002-06-20 | 2004-01-22 | Toshiba Corp | Valve arrangement and method of manufacturing the valve arrangement |
| CN103320069A (en) * | 2013-05-15 | 2013-09-25 | 南京天力信科技实业有限公司 | Modified epoxy resin bar-planting glue suitable for wet environment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62255671A (en) * | 1986-04-26 | 1987-11-07 | Nippon Beeles- Kk | Control valve |
-
1993
- 1993-09-30 JP JP5244624A patent/JP2637039B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62255671A (en) * | 1986-04-26 | 1987-11-07 | Nippon Beeles- Kk | Control valve |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004019918A (en) * | 2002-06-20 | 2004-01-22 | Toshiba Corp | Valve arrangement and method of manufacturing the valve arrangement |
| CN103320069A (en) * | 2013-05-15 | 2013-09-25 | 南京天力信科技实业有限公司 | Modified epoxy resin bar-planting glue suitable for wet environment |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2637039B2 (en) | 1997-08-06 |
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