JPH0541692B2 - - Google Patents
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- Publication number
- JPH0541692B2 JPH0541692B2 JP1283073A JP28307389A JPH0541692B2 JP H0541692 B2 JPH0541692 B2 JP H0541692B2 JP 1283073 A JP1283073 A JP 1283073A JP 28307389 A JP28307389 A JP 28307389A JP H0541692 B2 JPH0541692 B2 JP H0541692B2
- Authority
- JP
- Japan
- Prior art keywords
- less
- corrosion resistance
- phosphoric acid
- stainless steel
- corrosion
- 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 - Fee Related
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- 238000005260 corrosion Methods 0.000 claims description 46
- 230000007797 corrosion Effects 0.000 claims description 46
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 36
- 230000003628 erosive effect Effects 0.000 claims description 20
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 18
- 239000002002 slurry Substances 0.000 claims description 16
- 239000012535 impurity Substances 0.000 claims description 13
- 229910001208 Crucible steel Inorganic materials 0.000 claims description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- 229910001039 duplex stainless steel Inorganic materials 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 229910052804 chromium Inorganic materials 0.000 claims description 9
- 239000010440 gypsum Substances 0.000 claims description 8
- 229910052602 gypsum Inorganic materials 0.000 claims description 8
- PASHVRUKOFIRIK-UHFFFAOYSA-L calcium sulfate dihydrate Chemical compound O.O.[Ca+2].[O-]S([O-])(=O)=O PASHVRUKOFIRIK-UHFFFAOYSA-L 0.000 claims description 7
- 229910052742 iron Inorganic materials 0.000 claims description 5
- 229910019142 PO4 Inorganic materials 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 4
- 239000010452 phosphate Substances 0.000 claims description 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 3
- 230000000694 effects Effects 0.000 description 15
- 238000012360 testing method Methods 0.000 description 13
- 239000011651 chromium Substances 0.000 description 10
- 239000000956 alloy Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 229910001566 austenite Inorganic materials 0.000 description 6
- 229910000859 α-Fe Inorganic materials 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 229910052750 molybdenum Inorganic materials 0.000 description 5
- 238000005299 abrasion Methods 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- WAIPAZQMEIHHTJ-UHFFFAOYSA-N [Cr].[Co] Chemical compound [Cr].[Co] WAIPAZQMEIHHTJ-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- QKCQJEFEQXXXTO-UHFFFAOYSA-N chromium;methane Chemical compound C.C.[Cr].[Cr].[Cr] QKCQJEFEQXXXTO-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000003009 desulfurizing effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 229910000856 hastalloy Inorganic materials 0.000 description 1
- 238000013101 initial test Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000010309 melting process Methods 0.000 description 1
- 239000002367 phosphate rock Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Description
（産業上の利用分野）
本発明は、湿式りん酸製造装置で使用されるり
ん酸石膏スラリーに対し優れた耐食性、耐エロー
ジヨン性を有する二相ステンレス鋳鋼に関するも
のである。
（従来の技術）
通常硫酸を使用して製造されるりん酸の湿式プ
ロセスにおいて、りん鉱石中に含まれる不純物
（塩化物、ふつ化物、硫酸塩、酸化物など）の多
くはそのままりん酸に混入し、りん酸石膏スラリ
ーを形成する。りん酸石膏スラリーの中に耐食性
並びに耐エロージヨン性に悪影響を及ぼす、いわ
ゆる腐食性不純物、摩耗性不純物が混在し、湿式
りん酸製造装置用材料の腐食・摩耗を促進するの
で、ここにりん酸石膏スラリーに対し耐食性と耐
エロージヨン性とを同時に兼ね備えた材料が要求
される。
湿式りん酸製造装置では、従来腐食性不純物の
多いりん酸に対しハステロイ合金、イリウム合金
などのNi基高合金材料とか、JIS SCS14（18Cr−
12Ni−2.5Mo−Fe）、SCS23（20Cr−28Ni−2Mo
−3Cu−Fe）などの高Ni系オーステナイトステ
ンレス合金材料が使用されている。前者はMoお
よびNiを多量に含有するため高価であるばかり
でなく、摩耗性不純物の多いりん酸石膏スラリー
に対しては耐エロージヨン性に劣り耐用期間が短
く、後者は腐食性不純物の多いりん酸石膏スラリ
ーに耐し耐食性、耐エロージヨン性とも不十分で
あり、経済的かつ耐腐食摩耗性に優れたステンレ
ス鋳鋼の開発が要望されている。
（発明が解決しようとする課題）
本考案は、腐食性不純物の多い湿式りん酸の製
造プロセスに用いられる従来の耐食材料における
課題を解決するにあたり、経済性、耐用寿命の向
上、使用条件の苛酷化への対処などの観点から鋭
意研究を重ねた結果見出した、経済的に有利でか
つりん酸石膏スラリーに対し優れた耐食性、耐エ
ロージヨン性を有する二相ステンレス鋳鋼を提供
することを目的とする。
（課題を解決するための手段および作用）
本考案は、Cr−Ni−Mo−Cu−Ｎ−Fe系ステ
ンレス鋼において、CrとMo複合増量添加がりん
酸石膏スラリーに対する耐食性、耐エロージヨン
性の改善に著効を発揮し、またこれにＷ，Coの
添加は耐食性の向上にさらに有効であるとの知見
に基づいてなされたものである。
本発明の二相ステンレス鋳鋼は、Ｃ：0.08wt％
以下、Si：2.0wt％以下、Mn：2.0wt％以下、
Ｐ：0.04wt％以下、Ｓ：0.03wt％以下、Ni：５
〜10wt％、Cr：28〜36wt％、Mo：２〜5wt％、
ただしCr（wt％）＋2.5×Mo（wt％）＝38（wt％）
以上、Cu：0.5〜3.0wt％、Ｎ：0.10〜0.30wt％を
含有し、残部が鉄および不可避不純物からなり、
所望によりこれらの元素と共にＷ：0.5〜2.0wt
％、Co：0.1〜1.0wt％を含有する。
以下、本発明二相ステンレス鋳鋼の成分限定理
由を詳しく説明する。
Ｃ：ステンレス鋳鋼の溶製上不可避的に混入し
てくる元素であるが、Ｃ含有量が多くなるとクロ
ム炭化物（Cr23C6）の析出により耐食性や靱性を
劣化させるので、0.08％以下とする。
Si：溶湯の脱酸剤のために必要な元素であり、
また鋳造性の改善に有効な元素であるが、材料
特性の劣化を招くので、2.0％を上限とする。
Mn：溶湯の脱酸・脱硫作用を有し、かつ鋳造
性の改善に有効な元素であるが、多量に含まれ
ると耐食性が低下するので、2.0％以下とする。
Ｐ：耐食性を上げるためには、その含有量を
0.04％以下とする。
Ｓ：耐食性を上げるためには、その含有量を
0.03％以下とする。
Ni：オーステナイト生成元素であり、かつフ
エライト相とオーステナイト相の相比を決定す
るために必要な元素である。優れた靭性および
耐食性を確保するためにNi量を５％以下とす
る。多量に含むとフエライト量が多くなり、フ
エライト相とオーステナイト相の相比のバラン
スが崩れ、耐食性を劣化させるので、上限を10
％とする。フエライト量は耐食性および耐エロ
ージヨン性を高水準に保つため、並びに靭性劣
化を防止するために30〜70％が好ましく、Cr
やMo等の元素の含有量に合わせて調整が必要
である。
Cr：フエライト生成元素であり、フエライト
相の耐食性および耐エロージヨン性の改善に有
効な元素である。なお、優れた耐食性および耐
エロージヨン性を確保するために、Cr量を28
％以上とし、フエライト量を30〜70％に調整す
るのが好ましく、本発明に必要なCr＋2.5Moの
値を38％以上にするためにもCr量を28％以上
に規定する。二相ステンレス鋳鋼の耐食性およ
び耐エロージヨン性を高水準に保つためには
CrおよびMoの複合増量が有効であり、特に
Moの効果が大きく、Cr＋2.5Moの値が38％以
上になると耐食性および耐エロージヨン性が顕
著に現れる。多量に含むと靭性を劣化させるの
で、上限を36％とする。
Mo：フエライト生成元素であり、Crと同じく
耐食性および耐エロージヨン性の改善に優れた
効果を有し、特に耐隙間腐食性および耐孔食性
の向上に著しい効果を有する。強腐食性のりん
酸石膏スラリーにおいて、2.0％以上の含有で
その効果が現われ、さらにCrとの複合増量の
場合にCr＋2.5Moの値が38％以上のときにその
効果が著しい。多量に含まれると、靭性を劣化
させるので、上限を5.0％とする。
Cu：オーステナイト生成元素であり、オース
テナイト相の固溶強化および耐食性の向上に効
果を有する。この効果を得るためには、少なく
とも0.5％を要する。多量に含まれると強度や
靭性を低下させるので、上限を3.0％とする。
Ｎ：オーステナイト生成元素であり、オーステ
ナイトの耐食性の改善に効果を有する。また、
オーステナイト相の固溶強化と耐エロージヨン
性の向上に効果を有する。この効果を得るため
には、0.10％以上を要するが、0.30％を超える
とブローホールを生じる。よつて0.10〜0.30％
とする。
Ｗ：フエライト生成元素であり、耐食性および
耐エロージヨン性の改善に有効である。この効
果を得るためには、0.5％以上必要であり、2.0
％を超えると効果は飽和状態に近づく。よつて
0.5〜2.0％とする。
Co：オーステナイト相の耐食性および耐エロ
ージヨン性を向上させる効果があり、そのため
には少なくとも0.1％を要するが、1.0％を超え
ると効果は飽和状態に近づく。よつて0.1〜1.0
％とする。
（実施例）
次に、実施例により本発明二相ステンレス鋳鋼
の材料特性について説明する。
第１表は実施例において供試された鋼の化学組
成を示す。第２表は機械的性質を示す。第３表は
粗製りん酸中での耐食性、石膏スラリー中での耐
腐食摩耗性およびりん酸製造プラントの反応槽中
での腐食性を示す。
第１表中の供試鋼のNo.１からNo.18までは二相ス
テンレス鋳鋼、No.19およびNo.20はそれぞれJIS
SCS 14，SCS23、No.21はハステロイＣである。
いずれの供試鋼についても、溶体化処理を実施し
た。
実施例 １
腐食試験は、りん酸製造の初期工程で得られた
高濃度の粗製りん酸（P2O5：43.5％、H2SO4：
5.35％、Ｆ：0.80％、Cl-：0.30％、Fe3+：1.17
％、Al3+：0.64％）を恒温水槽で90℃に加熱し
て、試験片を50時間浸漬して腐食減量を求めた。
この腐食減量から腐食速度（ｇ／m2・hr）を求
め、耐食性を評価した。
実施例 ２
腐食摩耗試験は、回転円板による方法を採用し
た。上記粗製りん酸に細粒径の石膏を28.7重量％
含む石膏スラリーを摩耗試験槽で90℃に加熱して
おき、試験片を回転円板に取付けた後に、磨耗試
験槽中で４時間連続でこの回転円板を周速
1.17m／ｓで回転させた。この試験を８回繰り返
し、試験片の摩耗量を測定した。摩耗量を最初の
試験片の重量で除して重量変化を求めた。
実施例 ３
製造プラントの反応槽中に浸漬した場合の腐食
試験では、本発明合金No.１、No.３、No.７および従
来材No.19、No.20、No.21を使用した。上記腐食摩耗
試験と同じ組成の粗製りん酸石膏スラリーが循環
している反応槽中に、これらの試験片を23日浸漬
した。なお、スラリー液の温度は90〜93℃に維持
されている。
前記試験結果から明らかなように、本発明合金
No.１〜No.７は、強度および硬度が高いと同時に、
粗製りん酸に耐する耐全面腐食性が極めて良く、
耐腐食摩耗性も極めて優れており、既存の
SCS14、SCS23、ハステロイＣに比して、卓越し
た材料特性を有することがわかる。
(Field of Industrial Application) The present invention relates to a duplex stainless steel cast steel having excellent corrosion resistance and erosion resistance against phosphogypsum slurry used in wet phosphoric acid production equipment. (Prior art) In the wet process of producing phosphoric acid, which is normally produced using sulfuric acid, many of the impurities contained in phosphate rock (chlorides, fluorides, sulfates, oxides, etc.) are mixed into the phosphoric acid as they are. and form a phosphogypsum slurry. Phosphate gypsum slurry contains so-called corrosive impurities and abrasive impurities that have a negative effect on corrosion resistance and erosion resistance, accelerating corrosion and abrasion of materials for wet phosphoric acid production equipment. A material is required for slurry that has both corrosion resistance and erosion resistance. In wet phosphoric acid production equipment, conventional phosphoric acid containing many corrosive impurities has been replaced with Ni-based high alloy materials such as Hastelloy alloy and Illium alloy, and JIS SCS14 (18Cr-
12Ni−2.5Mo−Fe), SCS23(20Cr−28Ni−2Mo
-3Cu-Fe) and other high-Ni austenitic stainless steel alloy materials are used. The former is not only expensive because it contains a large amount of Mo and Ni, but also has poor erosion resistance and short service life when used with phosphogypsum slurry that contains many abrasive impurities, while the latter uses phosphoric acid that contains many corrosive impurities. The corrosion resistance and erosion resistance of gypsum slurry are insufficient, and there is a need for the development of an economical stainless steel cast steel with excellent corrosion and wear resistance. (Problems to be Solved by the Invention) The present invention aims to solve the problems of conventional corrosion-resistant materials used in the wet phosphoric acid manufacturing process, which contains many corrosive impurities, by improving economic efficiency, improving service life, and harsh usage conditions. Our objective is to provide a duplex stainless steel cast steel that is economically advantageous and has excellent corrosion resistance and erosion resistance against phosphate gypsum slurry, which we discovered as a result of intensive research from the perspective of dealing with corrosion. . (Means and effects for solving the problem) The present invention proposes that in Cr-Ni-Mo-Cu-N-Fe stainless steel, the combined addition of Cr and Mo improves corrosion resistance and erosion resistance against phosphate gypsum slurry. This was based on the knowledge that the addition of W and Co to this is even more effective in improving corrosion resistance. The duplex stainless steel cast steel of the present invention has C: 0.08wt%
Below, Si: 2.0wt% or less, Mn: 2.0wt% or less,
P: 0.04wt% or less, S: 0.03wt% or less, Ni: 5
~10wt%, Cr: 28~36wt%, Mo: 2~5wt%,
However, Cr (wt%) + 2.5 × Mo (wt%) = 38 (wt%)
Contains Cu: 0.5 to 3.0 wt%, N: 0.10 to 0.30 wt%, and the remainder consists of iron and inevitable impurities,
W: 0.5-2.0wt with these elements as desired
%, Co: 0.1-1.0wt%. Hereinafter, the reasons for limiting the components of the duplex stainless steel cast steel of the present invention will be explained in detail. C: This is an element that is unavoidably mixed into the melting process of cast stainless steel. If the C content increases, corrosion resistance and toughness deteriorate due to the precipitation of chromium carbide (Cr 23 C 6 ), so it should be kept at 0.08% or less. . Si: An element necessary for deoxidizing molten metal,
Further, although it is an effective element for improving castability, it causes deterioration of material properties, so the upper limit is set at 2.0%. Mn: An element that has a deoxidizing and desulfurizing effect on molten metal and is effective in improving castability, but if it is included in a large amount, corrosion resistance will decrease, so Mn should be kept at 2.0% or less. P: In order to increase corrosion resistance, its content should be
0.04% or less. S: In order to increase corrosion resistance, its content should be
0.03% or less. Ni: An austenite-forming element and an element necessary for determining the phase ratio between the ferrite phase and the austenite phase. In order to ensure excellent toughness and corrosion resistance, the amount of Ni is 5% or less. If it is included in a large amount, the amount of ferrite will increase and the balance of the phase ratio between the ferrite phase and the austenite phase will be disrupted, deteriorating the corrosion resistance, so the upper limit should be set to 10.
%. The amount of ferrite is preferably 30 to 70% in order to maintain high levels of corrosion resistance and erosion resistance, and to prevent deterioration of toughness.
It is necessary to adjust it according to the content of elements such as and Mo. Cr: A ferrite-forming element, which is effective in improving the corrosion resistance and erosion resistance of the ferrite phase. In addition, in order to ensure excellent corrosion resistance and erosion resistance, the amount of Cr was increased to 28
% or more, and it is preferable to adjust the ferrite amount to 30 to 70%. In order to make the value of Cr+2.5Mo necessary for the present invention 38% or more, the Cr amount is specified to be 28% or more. To maintain the high level of corrosion resistance and erosion resistance of duplex stainless steel cast steel
Combined increase of Cr and Mo is effective, especially
The effect of Mo is large, and when the value of Cr+2.5Mo is 38% or more, corrosion resistance and erosion resistance become noticeable. If contained in large amounts, toughness deteriorates, so the upper limit is set at 36%. Mo: A ferrite-forming element, which, like Cr, has an excellent effect on improving corrosion resistance and erosion resistance, and in particular has a remarkable effect on improving crevice corrosion resistance and pitting corrosion resistance. In highly corrosive phosphogypsum slurry, the effect appears when the content is 2.0% or more, and in the case of compound increase with Cr, the effect is remarkable when the value of Cr + 2.5Mo is 38% or more. If contained in large amounts, the toughness deteriorates, so the upper limit is set at 5.0%. Cu: An austenite-forming element that is effective in solid solution strengthening of the austenite phase and improving corrosion resistance. To obtain this effect, at least 0.5% is required. If contained in large amounts, strength and toughness will decrease, so the upper limit is set at 3.0%. N: An austenite-forming element, which is effective in improving the corrosion resistance of austenite. Also,
It is effective in solid solution strengthening of the austenite phase and improving erosion resistance. To obtain this effect, a content of 0.10% or more is required, but if it exceeds 0.30%, blowholes will occur. 0.10~0.30%
shall be. W: A ferrite-forming element, which is effective in improving corrosion resistance and erosion resistance. To obtain this effect, 0.5% or more is required, and 2.0
%, the effect approaches saturation. Sideways
0.5-2.0%. Co: has the effect of improving the corrosion resistance and erosion resistance of the austenite phase, and for this purpose requires at least 0.1%, but if it exceeds 1.0%, the effect approaches saturation. Yotsute 0.1~1.0
%. (Example) Next, the material properties of the duplex stainless steel cast steel of the present invention will be explained using examples. Table 1 shows the chemical composition of the steels tested in the examples. Table 2 shows the mechanical properties. Table 3 shows the corrosion resistance in crude phosphoric acid, the corrosion abrasion resistance in gypsum slurry and the corrosion resistance in the reactor of a phosphoric acid production plant. Test steels No. 1 to No. 18 in Table 1 are duplex stainless steel cast steel, and No. 19 and No. 20 are JIS
SCS 14, SCS23, and No. 21 are Hastelloy C.
All sample steels were subjected to solution treatment. Example 1 Corrosion tests were conducted using highly concentrated crude phosphoric acid (P 2 O 5 : 43.5%, H 2 SO 4 : obtained in the initial process of phosphoric acid production).
5.35%, F: 0.80%, Cl - : 0.30%, Fe 3+ : 1.17
%, Al 3+ : 0.64%) was heated to 90°C in a constant temperature water bath, and the test piece was immersed for 50 hours to determine the corrosion loss. The corrosion rate (g/m 2 ·hr) was determined from this corrosion loss, and the corrosion resistance was evaluated. Example 2 For the corrosion wear test, a method using a rotating disk was adopted. Add 28.7% by weight of fine-grained gypsum to the above crude phosphoric acid.
The containing gypsum slurry was heated to 90℃ in an abrasion test tank, the test piece was mounted on a rotating disk, and the rotating disk was kept at a circumferential speed for 4 hours continuously in the abrasion test tank.
It rotated at 1.17m/s. This test was repeated eight times and the amount of wear on the test piece was measured. Weight change was determined by dividing the amount of wear by the weight of the initial test piece. Example 3 In a corrosion test when immersed in a reaction tank of a manufacturing plant, alloys No. 1, No. 3, and No. 7 of the present invention and conventional materials No. 19, No. 20, and No. 21 were used. These test pieces were immersed for 23 days in a reaction tank in which a crude phosphogypsum slurry having the same composition as in the corrosion wear test was circulated. Note that the temperature of the slurry liquid is maintained at 90 to 93°C. As is clear from the above test results, the alloy of the present invention
No. 1 to No. 7 have high strength and hardness, and at the same time
Extremely good overall corrosion resistance against crude phosphoric acid.
It also has excellent corrosion and wear resistance, making it possible to replace existing
It can be seen that it has superior material properties compared to SCS14, SCS23, and Hastelloy C.
【表】【table】
【表】【table】
【表】【table】
【表】
（発明の効果）
本発明の二相ステンレス鋳鋼は耐食性、耐エロ
ージヨン性に優れ、かつ強靱である上に、Ni基
高合金と比較して安価である経済的効果も併せて
具備しており、腐食性不純物の多い湿式りん酸製
造装置でも特に使用温度が高く、腐食不純物の濃
度が高いなどの使用条件の苛酷な箇所で使用され
る時、耐用寿命の向上に最大の効果を発揮する。[Table] (Effects of the invention) The duplex stainless steel cast steel of the present invention has excellent corrosion resistance, erosion resistance, and toughness, and also has the economical effect of being cheaper than Ni-based high alloys. Even in wet phosphoric acid manufacturing equipment with many corrosive impurities, it is most effective in improving the service life when used in locations with harsh operating conditions such as high operating temperatures and high concentrations of corrosive impurities. do.
Claims (1)
2.0wt％以下、Ｐ：0.04wt％以下、Ｓ：0.03wt％
以下、Ni：５〜10wt％、Cr：28〜36wt％、
Mo：２〜5wt％、ただしCr（wt％）＋2.5×Mo
（wt％）＝38（wt％）以上、Cu：0.5〜3.0wt％、
Ｎ：0.10〜0.30wt％を含有し、残部が鉄および不
可避不純物からなることを特徴とするりん酸石膏
スラリーに対し優れた耐食性、耐エロージヨン性
を有する湿式りん酸製造装置用二相ステンレス鋳
鋼。 ２ Ｃ：0.08wt％以下、Si：2.0wt％以下、Mn：
2.0wt％以下、Ｐ：0.04wt％以下、Ｓ：0.03wt％
以下、Ni：５〜10wt％、Cr：28〜36wt％、
Mo：２〜5wt％、ただしCr（wt％）＋2.5×Mo
（wt％）＝38（wt％）以上、Cu：0.5〜3.0wt％、
Ｎ：0.10〜0.30wt％、Ｗ：0.5〜2.0wt％を含有し、
残部が鉄および不可避不純物からなることを特徴
とするりん酸石膏スラリーに対し優れた耐食性、
耐エロージヨン性を有する湿式りん酸製造装置用
二相ステンレス鋳鋼。 ３ Ｃ：0.08wt％以下、Si：2.0wt％以下、Mn：
2.0wt％以下、Ｐ：0.04wt％以下、Ｓ：0.03wt％
以下、Ni：５〜10wt％、Cr：28〜36wt％、
Mo：２〜5wt％、ただしCr（wt％）＋2.5×Mo
（wt％）＝38（wt％）以上、Cu：0.5〜3.0wt％、
Ｎ：0.10〜0.30wt％、Ｗ：0.5〜2.0wt％、Co：0.1
〜1.0wt％を含有し、残部が鉄および不可避不純
物からなることを特徴とするりん酸石膏スラリー
に対し優れた耐食性、耐エロージヨン性を有する
湿式りん酸製造装置用二相ステンレス鋳鋼。[Claims] 1 C: 0.08wt% or less, Si: 2.0wt% or less, Mn:
2.0wt% or less, P: 0.04wt% or less, S: 0.03wt%
Below, Ni: 5-10wt%, Cr: 28-36wt%,
Mo: 2 to 5wt%, Cr (wt%) + 2.5×Mo
(wt%) = 38 (wt%) or more, Cu: 0.5 to 3.0wt%,
A duplex stainless steel cast steel for wet phosphoric acid production equipment, which has excellent corrosion resistance and erosion resistance against phosphate gypsum slurry, containing 0.10 to 0.30 wt% of N, with the remainder consisting of iron and inevitable impurities. 2 C: 0.08wt% or less, Si: 2.0wt% or less, Mn:
2.0wt% or less, P: 0.04wt% or less, S: 0.03wt%
Below, Ni: 5-10wt%, Cr: 28-36wt%,
Mo: 2 to 5wt%, Cr (wt%) + 2.5×Mo
(wt%) = 38 (wt%) or more, Cu: 0.5 to 3.0wt%,
Contains N: 0.10 to 0.30 wt%, W: 0.5 to 2.0 wt%,
Excellent corrosion resistance against phosphogypsum slurry, the remainder of which is composed of iron and unavoidable impurities.
Duplex stainless steel cast steel for wet phosphoric acid production equipment with erosion resistance. 3 C: 0.08wt% or less, Si: 2.0wt% or less, Mn:
2.0wt% or less, P: 0.04wt% or less, S: 0.03wt%
Below, Ni: 5-10wt%, Cr: 28-36wt%,
Mo: 2 to 5wt%, Cr (wt%) + 2.5×Mo
(wt%) = 38 (wt%) or more, Cu: 0.5 to 3.0wt%,
N: 0.10-0.30wt%, W: 0.5-2.0wt%, Co: 0.1
A duplex stainless steel cast steel for wet phosphoric acid manufacturing equipment, which has excellent corrosion resistance and erosion resistance against phosphogypsum slurry containing ~1.0wt%, with the remainder consisting of iron and unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28307389A JPH03146641A (en) | 1989-11-01 | 1989-11-01 | Duplex stainless cast steel for manufacturing apparatus for wet type phosphoric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28307389A JPH03146641A (en) | 1989-11-01 | 1989-11-01 | Duplex stainless cast steel for manufacturing apparatus for wet type phosphoric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03146641A JPH03146641A (en) | 1991-06-21 |
| JPH0541692B2 true JPH0541692B2 (en) | 1993-06-24 |
Family
ID=17660858
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28307389A Granted JPH03146641A (en) | 1989-11-01 | 1989-11-01 | Duplex stainless cast steel for manufacturing apparatus for wet type phosphoric acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03146641A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE501321C2 (en) * | 1993-06-21 | 1995-01-16 | Sandvik Ab | Ferrite-austenitic stainless steel and use of the steel |
| JP3155431B2 (en) * | 1994-10-26 | 2001-04-09 | 株式会社安来製作所 | Duplex stainless cast member and method of manufacturing the same |
| SE519589C2 (en) * | 1998-02-18 | 2003-03-18 | Sandvik Ab | Use of high-strength stainless steel in equipment for making caustic soda |
| SE531593C2 (en) * | 2007-10-26 | 2009-06-02 | Sandvik Intellectual Property | Heat exchanger for phosphoric acid environment |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5021136A (en) * | 1973-06-26 | 1975-03-06 | ||
| JPS52153821A (en) * | 1976-06-17 | 1977-12-21 | Nippon Yakin Kogyo Co Ltd | High strength austenitic ferritic stainles steel |
| JPS57131347A (en) * | 1981-02-09 | 1982-08-14 | Sumitomo Metal Ind Ltd | Two-phase stainless steel for oil well pipe with superior corrosion resistance |
| JPS60165362A (en) * | 1984-02-07 | 1985-08-28 | Kubota Ltd | Highly corrosion resistant and high yield strength two- phase stainless steel |
| JPS6389618A (en) * | 1986-10-02 | 1988-04-20 | Nkk Corp | Production of highly corrosion resistant two-phase stainless steel |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0788556B2 (en) * | 1987-07-28 | 1995-09-27 | ニダック株式会社 | High yield strength and high corrosion resistance duplex stainless cast steel |
-
1989
- 1989-11-01 JP JP28307389A patent/JPH03146641A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5021136A (en) * | 1973-06-26 | 1975-03-06 | ||
| JPS52153821A (en) * | 1976-06-17 | 1977-12-21 | Nippon Yakin Kogyo Co Ltd | High strength austenitic ferritic stainles steel |
| JPS57131347A (en) * | 1981-02-09 | 1982-08-14 | Sumitomo Metal Ind Ltd | Two-phase stainless steel for oil well pipe with superior corrosion resistance |
| JPS60165362A (en) * | 1984-02-07 | 1985-08-28 | Kubota Ltd | Highly corrosion resistant and high yield strength two- phase stainless steel |
| JPS6389618A (en) * | 1986-10-02 | 1988-04-20 | Nkk Corp | Production of highly corrosion resistant two-phase stainless steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03146641A (en) | 1991-06-21 |
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