EP0516955B1 - Acier austénitique à teneur élevé en silicium et résistant à la corrosion - Google Patents

Acier austénitique à teneur élevé en silicium et résistant à la corrosion Download PDF

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Publication number
EP0516955B1
EP0516955B1 EP92106710A EP92106710A EP0516955B1 EP 0516955 B1 EP0516955 B1 EP 0516955B1 EP 92106710 A EP92106710 A EP 92106710A EP 92106710 A EP92106710 A EP 92106710A EP 0516955 B1 EP0516955 B1 EP 0516955B1
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EP
European Patent Office
Prior art keywords
silicon
max
nickel
corrosion
chromium
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
Application number
EP92106710A
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German (de)
English (en)
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EP0516955A1 (fr
Inventor
Felix Lvovich Dr. Levin
Agnessa Dmitrievna Dr. Goronkova
Vladimir Ivanovich Zuzinskaja Dr. Krasnykh
Rolf Kirchheiner
Michael Dr. Köhler
Ulrich Dr. Heubner
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.)
Krupp VDM GmbH
Ip Bardin Central Research Institute For Iron And Steel Industry
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Krupp VDM GmbH
Ip Bardin Central Research Institute For Iron And Steel Industry
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Publication of EP0516955A1 publication Critical patent/EP0516955A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel

Definitions

  • the invention relates to a highly silicon-containing, corrosion-resistant, austenitic steel and its use for handling strongly oxidizing media, such as hot, highly concentrated sulfuric acid and hot, highly concentrated nitric acid.
  • the steel X2CrNiSi1815 which contains 17 to 18% chromium and 14.5 to 15.5% nickel, also contains 3.7 to 4.3% silicon (all figures in mass%), especially for handling highly concentrated hot nitric acid.
  • a high corrosion resistance in over azeotropic, mainly highly concentrated nitric acid can only be achieved by a silicon content of at least 3.7% (EM Horn, A. kugler, Z. Werkstofftechnik, Vol. 8, 1977, pp. 362 to 370, 410 to 417) .
  • the chromium content is then approx. 18%, so that passivation can also take place in other aqueous solutions.
  • the relatively high nickel content of approx. 15% is required to achieve an austenitic structure.
  • DE-OS 28 22 224 specifies a steel with 2.5 to 5% silicon, 15 to 20% chromium, 10 to 22% nickel, max. 2% manganese, max. 0.10% carbon and additives of another alloy component, consisting of tantalum, zirconium or a mixture of niobium and tantalum and / or zirconium for the production of corrosion-resistant spring plates.
  • GB-PS 2 036 077 discloses, inter alia, an austenitic steel with improved oxidation resistance at high Temperatures, which consist of 1 to 5% silicon, 15 to 30% chromium, 7 to 35% nickel, not more than 3% manganese, max. 0.10% carbon, remainder iron and impurities, the sulfur content also being limited to max. 0.003% is restricted.
  • a steel with a silicon content increased to 5 to 5.6% is also offered on the market, the nickel content being approx. 17.5% is increased in order to still be able to set an austenitic structure.
  • GB-A 2 122 594 claims the use of such a steel for plant parts which are required in the production of sulfuric acid. Nevertheless, a higher silicon content than approx. 4.5% according to the known state of the art generally not chosen, because with chrome contents of approx. 18%, the precipitation of carbides and intermetallic phases is accelerated overall by increasing silicon contents.
  • EP-A 0 135 320 proposes a silicon-containing austenitic-ferritic steel which is said to be particularly suitable for the handling of those nitric acid solutions which are used in the refurbishment of nuclear reactor fuel elements. Its composition is specified with 2 to 6% silicon, 20 to 35% chromium, 3 to 27% Nickel, 0.1 to 2% manganese, max. 0.03% nitrogen, max. 0.04% carbon, at least one of the elements niobium, titanium or tantalum with an amount of 8 times the carbon content or more, but max. 1%, balance essentially iron.
  • EP-PS 0 135 321 discloses a silicon-containing austenitic steel with improved resistance to corrosion caused by nitric acid, the composition of which is indicated as follows: 2 to 6% silicon, 20 to 35% chromium, 17 to 50% nickel, 0.01 to 8% manganese, max. 0.03% nitrogen, max. 0.03% carbon, at least one of the elements niobium, titanium and tantalum with an amount of 8 times the carbon content or more, but max. 1%, balance essentially iron.
  • a corrosion rate of less than 0.3 mm / year, tested in 95.6% sulfuric acid at 110 ° C can be achieved with the following alloy composition: 4.1 to 12% silicon, 6 to 22% chromium, 10 to 40% nickel, 0.6 to 4% copper, max. 4% manganese, max. 1.5% molybdenum plus 1/2 tungsten, max. 0.2% nitrogen, max. 0.06% carbon, in total max. 2% for the elements niobium, tantalum, zirconium and vanadium, the rest essentially iron.
  • the optimum silicon content is usually 7.5 to 10%, chromium preferably 9 to 14%, nickel preferably 14 to 20% and copper 2 to 3%.
  • Table 2 shows the corrosion removal of these alloys in 96 and 98.5% sulfuric acid at 150 and 200 ° C. Table 2 first makes it clear that the values given there for the averaged linear corrosion removal are apparently sufficiently reproducible, because in the case of test alloys No. 1, 4 and 5, where 2 series were tested in each case, the mean values of the measurements are so close to one another, that it is possible to differentiate the behavior of these alloys from that of the other alloys. It can then be seen in Table 2 that the corrosion removal in 98.5% sulfuric acid is consistently less than in 96% sulfuric acid. For an assessment of the alloys with regard to their usability in hot sulfuric acid with a concentration of 96% and above, the corrosion removal in 96% sulfuric acid is decisive.
  • the alloys according to the invention it follows that their silicon content must be as high as possible. This is opposed to the fact that, firstly, both silicon and chromium are strong ferrite formers, secondly, the alloy should contain no or only a small amount of ferrite for reasons of easy processability, thirdly, chromium contents of up to approximately 13%, but at least approximately 8%, are required in order to obtain one to ensure full to satisfactory rust resistance (cf. stainless steels - properties, processing, application - 2nd edition, Verlag Stahleisen mbH, Düsseldorf, 1989, p. 19), fourth, the content of nickel as an austenite former that counteracts the ferrite-forming elements silicon and chromium must be as small as possible for several reasons.
  • the alloy No. 6 produced by the company still has an inhomogeneous structure with dispersed Cr 3 Ni 5 Si 2 silicide which is unusable for the application even with a sheet thickness of 5 mm (FIG. 1) .
  • a homogeneous austenitic structure is only available after further processing on a 2 mm sheet thickness (Fig. 2) .
  • This compensation is difficult in the case of the high-silicon alloys because the low solidus temperature does not allow high heating and hot forming temperatures, which would bring about a rapid concentration compensation.
  • the solidus temperature was determined, for example, for alloy No. 8 to be 1155 ° C.
  • a nickel content of approx. 25% as in the case of alloy no. 6 with a high silicon content represents an upper limit.
  • alloy no. 7 with approx. 22% nickel is the first sign of ferrite in the structure.
  • the lower limit for the nickel content of the alloy according to the invention must therefore be somewhat below, that is to say approximately 20%. If you tolerate a corrosion removal of max. In 96% sulfuric acid at 150 ° C. 0.3 mm / year according to the deduction index 4 of DIN 50 905 sheet 2, so calculated for the alloy according to claim 2 from Eq.
  • Alloys No. 6 (6.6% Si) and No. 7 (7.2% Si) in Table 2 represent two exemplary embodiments of the alloy according to claim 2. It can be seen that in 96% sulfuric acid at 150 ° C. their corrosion removal at max. 0.3 mm / year. The corrosion resistance can therefore be described as good here. At 200 ° C with higher corrosion removal (0.69 or 0.76 mm / year) there is still a limit in the applicability with a corresponding corrosion surcharge when determining the wall thickness. In the steel composition according to claim 2, manganese contents up to 2% have a positive effect on the corrosion rate.
  • up to 10% of the nickel content starting from 20 to 25% nickel, is advantageously replaced individually or together with up to 10% manganese and / or cobalt, with at least 4.5% manganese or Alloy 2% cobalt.
  • the lower limit of the nickel content is 10%, a corrosion removal below 0.3 mm / year is then to be extrapolated even for 200 ° C.
  • the present invention provides a silicon-containing austenitic steel alloy which, on the one hand, is sufficiently corrosion-resistant due to its defined composition, without copper having to be alloyed, and, on the other hand, also in large formats with the means of conventional steelworks technology, as is the case with apparatus construction Sheets and pipes are required, can be processed by hot and / or cold forming, without the need to add further elements which improve formability, such as magnesium, aluminum, calcium and / or rare earths.
  • the corrosion behavior in hot concentrated nitric acid was measured in red fuming nitric acid (content at least 99.5% HNO 3 ) by immersion tests in a 10 l distillation apparatus with a reflux condenser. The samples were tested in boiling acid. The boiling point was about 85 ° C below atmospheric pressure.
  • the solution-annealed condition of the samples (1100 ° C./20min, water-quenched) resulted in a corrosion removal of less than 0.005 mm / year, which also occurred after a sensitization treatment of 10 min at 700 ° C. with subsequent water cooling and not increased from 20 min at 600 ° C with subsequent air cooling.
  • the alloy according to the invention is also well suited for handling other highly oxidizing media, such as chromic acid.
  • Table 1 Chemical composition of eight test alloys, mass content in% No. Si Cr Ni C. Mn Alloys 1 5.3 17.9 25.5 0.007 1.7 State of the art 2nd 5.6 19.0 25.7 0.013 State of the art 3rd 5.7 9.0 18.8 0.024 State of the art 4th 5.9 9.0 18.4 0.007 1.7 State of the art 5 6.1 8.9 21.9 0.006 1.6 According to the invention 6 6.6 9.2 24.9 0.005 1.4 According to the invention 7 7.2 8.9 21.9 0.006 1.4 Balance iron and unavoidable impurities Corrosion removal of silicon alloy steels in highly concentrated hot sulfuric acid, linear removal rates in mm / year, mean values from measurements over 7, 14 and 21 to 23 days 96% H 2 SO 4 98.5% H 2 SO 4 No.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Materials For Medical Uses (AREA)
  • Preventing Corrosion Or Incrustation Of Metals (AREA)
  • Laminated Bodies (AREA)

Claims (7)

  1. Acier austénitique à teneur élevée en silicium et résistant à la corrosion, caractérisé par des teneurs en éléments d'alliage (en % en masse) de max. 0,02 % de carbone 10 à 25 % de nickel 8 à 13 % de chrome 6,5 à 8 % de silicium 0 à 10 % de manganèse et/ou de cobalt max. 0,010 % de soufre max. 0,025 % de phosphore
    le reste étant constitué de fer et des impuretés inévitables.
  2. Acier selon la revendication 1, caractérisé en ce qu'il contient max. 0,02 % de carbone 20 à 25 % de nickel 8 à 13 % de chrome 6,5 à 7,5 % de silicium 0 à 2 % de manganèse.
  3. Acier selon la revendication 1, caractérisé en ce qu'il contient max. 0,02 % de carbone 10 à 20 % de nickel 8 à 13 % de chrome 7,5 à 8 % de silicium 4,5 à 10 % de manganèse.
  4. Acier selon la revendication 1, caractérisé en ce qu'il contient max. 0,02 % de carbone 10 à 23 % de nickel 8 à 13 % de chrome 7,5 à 8 % de silicium 2 à 10 % de cobalt.
  5. Acier selon la revendication 1, caractérisé en ce qu'il contient max. 0,02 % de carbone 10 à 20 % de nickel 8 à 13 % de chrome 7,5 à 8 % de silicium au moins 4,5 % de manganèse. au moins 2,0 % de cobalt,
    et dans lequel la somme des teneurs en manganèse et en cobalt est limitée à 10 %.
  6. Utilisation d'un acier selon l'une des revendications 1 à 5 pour la fabrication d'objets résistant à la corrosion pour la manipulation l'acide sulfurique chaud et fortement concentré, l'acide nitrique chaud et fortement concentré et d'autres milieux fortement oxydants comme l'acide chromique.
  7. Utilisation selon la revendication 6 sous forme de tôles laminées, de bandes, de tubes, de barres, de fils et d'autres formes de produits.
EP92106710A 1991-06-05 1992-04-18 Acier austénitique à teneur élevé en silicium et résistant à la corrosion Expired - Lifetime EP0516955B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4118437 1991-06-05
DE4118437A DE4118437A1 (de) 1991-06-05 1991-06-05 Hochsiliziumhaltiger, korrosionsbestaendiger, austenitischer stahl

Publications (2)

Publication Number Publication Date
EP0516955A1 EP0516955A1 (fr) 1992-12-09
EP0516955B1 true EP0516955B1 (fr) 1996-06-19

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EP92106710A Expired - Lifetime EP0516955B1 (fr) 1991-06-05 1992-04-18 Acier austénitique à teneur élevé en silicium et résistant à la corrosion

Country Status (10)

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US (1) US5296054A (fr)
EP (1) EP0516955B1 (fr)
JP (1) JPH05195166A (fr)
AT (1) ATE139578T1 (fr)
CA (1) CA2070535A1 (fr)
DE (1) DE4118437A1 (fr)
ES (1) ES2090403T3 (fr)
MA (1) MA22669A1 (fr)
PL (1) PL170353B1 (fr)
TW (1) TW198067B (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4213325A1 (de) * 1992-04-23 1993-10-28 Bayer Ag Verwendung von Knet- und Gußwerkstoffen sowie Schweißzusatzwerkstoffen für mit heißer konzentrierter Schwefelsäure oder Oleum beaufschlagte Bauteile sowie Verfahren zur Herstellung von Schwefelsäure
DE4308151C2 (de) * 1993-03-15 1995-01-19 Bayer Ag Verwendung von Knet- und Gußwerkstoffen sowie Schweißzusatzwerkstoffen aus austenitischem Stahl für mit heißer konzentrierter Schwefelsäure oder Oleum beaufschlagte Bauteile
DE4342188C2 (de) * 1993-12-10 1998-06-04 Bayer Ag Austenitische Legierungen und deren Verwendung
GB9506677D0 (en) * 1995-03-31 1995-05-24 Rolls Royce & Ass A stainless steel alloy
US6978885B1 (en) 2004-07-27 2005-12-27 Rexnord Industries, Inc. Hinge conveyor chain
JP4934682B2 (ja) * 2006-02-08 2012-05-16 アルファ ラバル タンク イクィップメント エイ／エス クリーニングヘッド
US9243314B2 (en) * 2011-07-29 2016-01-26 Nippon Steel & Sumitomo Metal Corporation Method for manufacturing high-Si austenitic stainless steel
GB2546809B (en) 2016-02-01 2018-05-09 Rolls Royce Plc Low cobalt hard facing alloy

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1420707A (en) * 1920-08-06 1922-06-27 Johnson Charles Morris Alloy steel
GB1261809A (en) * 1969-04-23 1972-01-26 Keiichi Ota High-strength silicon steel
BE754818A (fr) * 1969-08-13 1971-01-18 Armco Steel Corp Acier inoxydable resistant a l'usure
GB1275007A (en) * 1970-09-16 1972-05-24 Nippon Silicolloy Kogyo Kabush High silicon over-laying alloy
JPS524418A (en) * 1975-06-24 1977-01-13 Sandvik Ab Stainless steel
JPS53144415A (en) * 1977-05-23 1978-12-15 Sumitomo Chem Co Ltd Anti-corrosive bellows
JPS5591960A (en) * 1978-12-28 1980-07-11 Sumitomo Chem Co Ltd High silicon-nickel-chromium steel with resistance to concentrated
JPS6033342A (ja) * 1983-08-05 1985-02-20 Sumitomo Metal Ind Ltd 耐硝酸性２相ステンレス鋼
CA1323511C (fr) * 1988-04-05 1993-10-26 Hisatoshi Tagawa Alliage de fer a memoire de formes a proprietes excellentes en rapport avec la memoire de formes, la resistance a la corrosion et la resistance a l'oxydation a haute temperature
DE3901028A1 (de) * 1989-01-14 1990-07-19 Bayer Ag Nichtrostende knet- und gusswerkstoffe sowie schweisszusatzwerkstoffe fuer mit heisser, konzentrierter schwefelsaeure beaufschlagte bauteile

Also Published As

Publication number Publication date
ES2090403T3 (es) 1996-10-16
ATE139578T1 (de) 1996-07-15
JPH05195166A (ja) 1993-08-03
DE4118437C2 (fr) 1993-07-22
PL170353B1 (pl) 1996-12-31
US5296054A (en) 1994-03-22
EP0516955A1 (fr) 1992-12-09
MA22669A1 (fr) 1993-07-01
PL294447A1 (en) 1993-01-25
DE4118437A1 (de) 1992-12-10
TW198067B (fr) 1993-01-11
CA2070535A1 (fr) 1992-12-06

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