CA1164685A - Corrosion resistant glassy metal alloys - Google Patents
Corrosion resistant glassy metal alloysInfo
- Publication number
- CA1164685A CA1164685A CA000361476A CA361476A CA1164685A CA 1164685 A CA1164685 A CA 1164685A CA 000361476 A CA000361476 A CA 000361476A CA 361476 A CA361476 A CA 361476A CA 1164685 A CA1164685 A CA 1164685A
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- Canada
- Prior art keywords
- alloys
- phosphorus
- metal alloys
- glassy metal
- atom percent
- Prior art date
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- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C45/00—Amorphous alloys
- C22C45/02—Amorphous alloys with iron as the major constituent
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Soft Magnetic Materials (AREA)
Abstract
ABSTRACT
CORROSION RESISTANT GLASSY METAL ALLOYS
Corrosion resistant glassy metal alloys are provided which evidence a greater degree of corrosion resistance than prior art glassy metal alloys and con-ventional crystalline stainless steel alloys. The cor-rosion resistant glassy metal alloys consist essentially of from about 0 to 18 atom percent nickel, from 7 to about 21 atom percent chromium, from 0 to about 8 atom percent molybdenum, from about 13 to 18 atom percent of at least one element selected from the group con-sisting of phosphorus, carbon and boron, other than phosphorus plus carbon, and the balance essentially iron with the proviso that the ratio of phosphorus to the sum of phosphorus, boron and carbon is greater than or equal to 0.64.
CORROSION RESISTANT GLASSY METAL ALLOYS
Corrosion resistant glassy metal alloys are provided which evidence a greater degree of corrosion resistance than prior art glassy metal alloys and con-ventional crystalline stainless steel alloys. The cor-rosion resistant glassy metal alloys consist essentially of from about 0 to 18 atom percent nickel, from 7 to about 21 atom percent chromium, from 0 to about 8 atom percent molybdenum, from about 13 to 18 atom percent of at least one element selected from the group con-sisting of phosphorus, carbon and boron, other than phosphorus plus carbon, and the balance essentially iron with the proviso that the ratio of phosphorus to the sum of phosphorus, boron and carbon is greater than or equal to 0.64.
Description
DESCRIPTION
CORROSION RESISTAI`IT GLASSY_MEl'AL ALLOYS
BACKGROUND OF THE INVENTION
Field of the Invent_on This invention relates to corrosion resistant glassy metal alloys.
5Description of the Prior Art The corrosion resistance of any given metal or alloy in a reducing mediura is often sharply different from its corrosion resistance in an oxidizing medium, with some metals and alloys being more resistant to reducing media and others to oxi~izing media. These differences in behavior are thought to be attributable to differences between the corrosion mechanism in a reducing medium and the corro~ion n,echanism in an oxidizing medium. I'hus, corrosive attack by a reduciny acid is generally considered to involve attack on the metal by hydrogen ions, resulting in the oxidation of metal to soluble ions and release of hydrogen gas.
Metals of relatively high nobility, therefore, as in-dicated by their positions in the galvanic series are generally resistant to corrosion by reduciny acid.
Attack by oxidizing media, on the other hand, does not involve release of hydrogen but commonly results in the forlilation of metal oxides or other metallic compounds at the metal surface. Unlike the situation with reducing acids, a favorable position relative to hydrogen in the electromotive series provides no insurance that a metal ;will not be rapidly attacked by an oxidizing medium.
, ~3~e~
However, certain elements, such as chromium, aluminum and silicon, form tough insoluble oxide ~ilms upon initial contact with an oxidizing medium, and such films serve as barriers against further reaction between ~he medium and the metal to prevent further corrosion from taking place.
Sulfuric acid solutions are not only very cor-rosive generally, but the nature of their corrosion properties varies markedly with both acid concentra~ion and tempera~ure. This variability relates at least in part to sulfuric acid's ambivalent assumption of both reducins and oxidizing properties as its concentration temperature and the nature and proportion of various contaminants are altered. As a consequence of this variability in its corrosive properties, few materials are available which are reasonably resistant to s~l~uric acid solution over a wide range of concentrations and temperatures.
Of the ]snown alloys which are demonstrably effective over wide ranges of sulfuric acid concentra-tions, many contain re~atively high proportions of nickel and chromium and are, thus, rather expensive.
Corrosion resistant crystalline alloys are well known and are exemplified by stainless steels, for example. Corrosion resistant glassy metal alloys are also well known, see, for e~ample~ U.S. Patent 3,856,513, which discloses a corrosion resistant glassy y, ~oNi38P14B6A12 (the subscripts are in atom percent), as being several orders of magnitude less reactive than stainless steels with concentrated hydro-chloric acidO Other prior art corrosion resistant glassy metal alloys include iron-nickel-chromium-phosphorus-carbon alloys~ However, these alloys evidence stress corrosion cracking and thus are not suitable in many applications, even though their corrosion resistance is superior to many other glassy metal alloys. -; A continuing need exists for corrosion resis-g ~ ~
;~ -tant alloy~ having a reï~tively low expensive metal content. In particular, a need has existed for such alloys in which the nickel and chrorniuln content is relatively low, since these are both expensive mate rials. At the same time, there is a need for such alloys which are not only low in nickel and chromiulTI~
but also have low proportions of other expensive compo-nents such as ~nolybdenum.
Summary of the Invention In accordance with the invention, a metal alloy is provided that is substantially glassy and resistant to corrosion in acid media. The glassy metal alloy consists essentially of from about 0 to 18 atom percent nickel, from 7 to about 21 atom percent chromium, from 0 to abou~ 8 atom percent molybdenum, from about 13 to 18 atom percent of at least one ele-ment selected from the group consisting of phosphorus, carbon and boron, other than phosphorus plus carbon, and the balance essentially iron with the proviso that the ratio of phosphorus to the sum of phosphorus, boron and carbon present is greater than or equal to 0.64.
Brief Description of the Drawings FIG. 1, on coordinates of potential and cur-rent density, is a plot of a typical curve for an active-passive alloy; and FIG. 2, on coordinates of potential and cur-rent density, is a plot of typical alloys of the inven-tion compared with prior art stainless steel and prior art glassy metal alloys.
Detailed Description of the Invention Potentiostatic anodic polarization measure-ments are performed by immersing a metallic electrode in an electrolyte solution and varying its potential in a stepwise manner with a special feedback power supply (i.e.l a potentiostat). If the current corresponding to each potential is recorded, an anodic polarization curve can be constructed. A typical curve for an active-passive alloy is shown in FIG. 1. Potential is 1 31 6~B85 ploted on the ordinate and the logarithm of the current density on the abscissa. The current density, which is equivalent to the alloy dissolution rate, at first in-creases with increasing potential (active region 10).
At more noble (positive) potentials, the dissolution - current density decreases and then remains at a low value (passive region 11). At very positive potentials, the dissolution rate again increases with increasing potential (transpassive region 12). The current maxi-mum which occurs at the primary passiv~ potential ~pp is termed the critical anodic current density Ic. The passive region beyins at the passive potential Ep and is characterized by the passive current density Ip Potentiostatic anodic polarization curves may be viewed as plots of solution oxidizing power (E) versus corrosion rate (current density). Thus, a typi-cal active-passive alloy possesses maximum corrosion resistance under moderately oxidiziny conditions. The corrosion resistance is lo~er under reducing conditions and in the presence of very strong oxidizers which cor-respond to the active and transpassive states, respec-tively. Passivation becornes easier as Epp becomes more negative and as Ic decreases. Therefore, it i5 possible to compare the ease of passivation of alloys on the basis of their anodic polarization curves, Also, corro-sion rates in the passive state can be directly compared on the basis of Ip values. Finally, the range of useful corrosion resistance can be estimated by noting the width of the passive region and the potential at whicn the transpassive region begins. Although actual anodic polarization curves sometimes deviate from the schematic illustration of FIG. 1, they can be compared on the same basis.
The corrosion resistant alloys of the inven-tion consist essentially of from about 0 to 18 atom per-cent nickel, from 7 to about 21 atom percent chromium, from 0 to about 8 atom percent molyb~enum, from about 13 to 18 atom percent of at least one element selected -~ 1 3 ~68~
froln the group consisting of phosphoru~, carbon and boron, other than phosphorus plus carbon, an~ the balance essentially iron with the proviso that the ratio of phosphorus to the sum o~ phosphorus~ carbon - 5 and boron is greater than or equal to 0.64.
Glassy metal alloys of the invention are forlned by cooling a melt of the desired composition at a rate of at least about 10 DC/sec. A variety of rapid quenching techniques, well known to the glassy metal alloy art, are available for producing glassy metal powders, wires, ribbon and sheet. Typically, a partic-ular composition is selected~ powders or granules of the requisite elements in the desired portions are melted and homogenized, and the molten alloy is rapidly quenched on a chill surface, such as a rapidly rotating cylinder, or in a suitable fluid medium, such as water.
Under these quenching conditions, a metastable, homo-geneous, ductile material is obtained. The metastable material may be amorphous or glassy, in which case there is no long range order. X-ray di~fraction patterns of glassy metal alloys show only a diffuse halo, similar to that observed for inorganic oxide glasses.
The amorphous metal alloys are at least 50%
amorphous, and preferably at least 80% amorphous, as measured by X-ray diffraction. However, a substantial degree of amorphousness approaching 100~ alrlorphous is obtained by forming these amorphous metal alloys in a partial vacuum. Ductility and corrosion resistance are thereby improved, and such alloys possessing a substan-tial degree of amorphousness are accordingly preferred.
Examples A number of iron-based glassy metal alloys were studied and compared with prior art glassy metal alloys and crystalline stainless steel alloys. Exposed electrode areas for as-cast glassy metal ribbons ranged from 0.3 to 1.0 cm . The ribbons were mounted (dull side out) on lucite rods. The plastic~lnetal interfaces were coated with lacquer to prevent crevice effects.
i 8 ~
-Stainless steel standards were in rod form wi~h ~n exposed area of about 5 cm2. The experiments were per-formed in nitrogen or hydrogen satura~ed electrolyte prepared from distilled water and reagent-grade chemi-cals. The electrodes were inserted into a Princeton Applied Research polarization cell and pre-exposed until the corrosion potential became nearly constant. Polari~
zation measurements were conducted in the noble direc-tion using a Potentiodyne. The scanning rate for glassy metal alloys was generally 1.5 V/hrO
Polarization curves for all alloys were obtained in lN H2S04 at 22C. Ma~erials exhibiting in-teresting charac~eristics were studied in other environments such as lN H2SO4 plus 5 percent NaCl, lON H2SO4, and 38 percent ~Cl. In addition, weight losses were determined in 6% FeC13 at 60C for 20 hours.
Ta'~le I compares alloy performance ln hydrogen-saturated 1~l E12SO4. Included are prior art crystalline and glassy metal alloys, as well as glassy metal alloys having compositions outside the scope of the invention.
1 6~6~
TABLE I
Values of IC ~ ~ 4 Composition, Atorn Percent Icc~2 Ip, 2 Fe Ni Cr P C B Other A/cm A/an Prior Art Crystalline Allo~s * 82 - 18 - - - - 4.0x10 2.4x10 ~* 72 8 20 - - - - 5.3x10 8.5x10 ***70 10 18 - - - 2 r~O 2.8x10 1.5x10 * 430 stainless steel ** 304 stainless steel *** 316 stainless steel Prior Art Amorphous Alloys 31.5 36 14.5 12.5 - 5.5 - 5.4x10 6 3.2x10 6 40 38 - 14 - 6 2Al Amorphous Alloys of This Invention _ -5 7 63. 7 - 20 16 - 0.3 - l.lx10 2.8x10 60. 7 - 21 18 - 0-3 ~ <1o-6 <1o-6 50. 217. 5 14 18 -` 0.3 - 9.0x10 7. 4xlO
60.2 - 14 18 _ 0.3 7.5 ~lo <10 7 <10-7 20 69.6 - 10 13 7 0. 4 - 1. 4xlO 8x10-7 59. 6 - 20 13 7 0. 4 - 1. lxlO 7 9. 5xlO 8 49.317.5 7 18 - 0.3 7.5 Mo <10 <10-7 Other ~rnorphous ~lloys 78.6 - 5 16 - 0.4 - 6.0xlO 4 5.8x10 5 25 74.7 - 7 18 - 0.3 - 2.8x10 3~6x10 6 73. 6 _ 10 16 - 0. 4 - 7. 6x10 5 2. 8xlO 6 72.1 2.5 5 13 7 0.4 - 6.9x10 4 3 . ox:L0~5 39.7 35 7 18 - 0.3 - 2.3x10 1.2x10 34 35.3 14 16 - 0.7 - 4.0x10 6 2.0x10 6 30 45.7 -- 21 17 -- 0.315 Mo Table II cornpares weiyht loss of alloys in 6 FeC13 at 60C for 20 hours. Again, prior art crystal-line and glassy metal alloys having compositions outside the scope of the invention are included for comparison.
5~BLE II
Dissolution of Alloys in . 6% FeCl , 60C, 20 hrs.
Alloy Con~osition, Atom Percent 10 Fe Ni Cr P C B Other % weight loss _ 72 - 20 ~ 6 18 - - - - 1.5 Prior ALt Amorphous Alloys 15 31.5 36 14.5 12.5 - 5.5 - 0 40 38 - 14 - 6 2Al Arnorphous Alloys of This Invention -63.7 - 20 16 - 0.3 - 0 60.7 - 21 18 - 0.3 - 0 2050.2 17.5 14 18 - 0.3 - 0 60.2 - 14 18 - 0~3 7.5 Mo 0 69.6 - 10 13 7 0.4 - 0 59.6 - 20 13 7 0.4 - 0 49.3 17.5 7 18 - 0.3 7.5 Mo 0 Other Amorpho~ Alloys 78.6 - 5 16 - 0.4 - 100 74.7 - 7 18 - 0.3 ~ 100 73.6 - 10 16 - 0.4 - 100 72.1 2.5 5 1?. 7 0.4 - 100 30 39.7 35 7 18 - 0.3 - 0 3435.3 14 16 - 0.7 - 0 45.7 - 21 18 - 0.3 15 .~o 0 On the basis of Ip values, the glassy metal alloys of the invention evidence values less than lx10 A/cm , with many values less than 10 A/c~n . Further, these alloys are stable in 6% Fe/C13. Alloys outside the invention are seen not to possess this combination of corros ion res is tance .
Having thus descri~ed the invention in rakher full detail~ it will be understood ~hat this detail need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all Ealling within the scope of the present : invention as defined by the subjoined claims.
,~ 10 ,';
CORROSION RESISTAI`IT GLASSY_MEl'AL ALLOYS
BACKGROUND OF THE INVENTION
Field of the Invent_on This invention relates to corrosion resistant glassy metal alloys.
5Description of the Prior Art The corrosion resistance of any given metal or alloy in a reducing mediura is often sharply different from its corrosion resistance in an oxidizing medium, with some metals and alloys being more resistant to reducing media and others to oxi~izing media. These differences in behavior are thought to be attributable to differences between the corrosion mechanism in a reducing medium and the corro~ion n,echanism in an oxidizing medium. I'hus, corrosive attack by a reduciny acid is generally considered to involve attack on the metal by hydrogen ions, resulting in the oxidation of metal to soluble ions and release of hydrogen gas.
Metals of relatively high nobility, therefore, as in-dicated by their positions in the galvanic series are generally resistant to corrosion by reduciny acid.
Attack by oxidizing media, on the other hand, does not involve release of hydrogen but commonly results in the forlilation of metal oxides or other metallic compounds at the metal surface. Unlike the situation with reducing acids, a favorable position relative to hydrogen in the electromotive series provides no insurance that a metal ;will not be rapidly attacked by an oxidizing medium.
, ~3~e~
However, certain elements, such as chromium, aluminum and silicon, form tough insoluble oxide ~ilms upon initial contact with an oxidizing medium, and such films serve as barriers against further reaction between ~he medium and the metal to prevent further corrosion from taking place.
Sulfuric acid solutions are not only very cor-rosive generally, but the nature of their corrosion properties varies markedly with both acid concentra~ion and tempera~ure. This variability relates at least in part to sulfuric acid's ambivalent assumption of both reducins and oxidizing properties as its concentration temperature and the nature and proportion of various contaminants are altered. As a consequence of this variability in its corrosive properties, few materials are available which are reasonably resistant to s~l~uric acid solution over a wide range of concentrations and temperatures.
Of the ]snown alloys which are demonstrably effective over wide ranges of sulfuric acid concentra-tions, many contain re~atively high proportions of nickel and chromium and are, thus, rather expensive.
Corrosion resistant crystalline alloys are well known and are exemplified by stainless steels, for example. Corrosion resistant glassy metal alloys are also well known, see, for e~ample~ U.S. Patent 3,856,513, which discloses a corrosion resistant glassy y, ~oNi38P14B6A12 (the subscripts are in atom percent), as being several orders of magnitude less reactive than stainless steels with concentrated hydro-chloric acidO Other prior art corrosion resistant glassy metal alloys include iron-nickel-chromium-phosphorus-carbon alloys~ However, these alloys evidence stress corrosion cracking and thus are not suitable in many applications, even though their corrosion resistance is superior to many other glassy metal alloys. -; A continuing need exists for corrosion resis-g ~ ~
;~ -tant alloy~ having a reï~tively low expensive metal content. In particular, a need has existed for such alloys in which the nickel and chrorniuln content is relatively low, since these are both expensive mate rials. At the same time, there is a need for such alloys which are not only low in nickel and chromiulTI~
but also have low proportions of other expensive compo-nents such as ~nolybdenum.
Summary of the Invention In accordance with the invention, a metal alloy is provided that is substantially glassy and resistant to corrosion in acid media. The glassy metal alloy consists essentially of from about 0 to 18 atom percent nickel, from 7 to about 21 atom percent chromium, from 0 to abou~ 8 atom percent molybdenum, from about 13 to 18 atom percent of at least one ele-ment selected from the group consisting of phosphorus, carbon and boron, other than phosphorus plus carbon, and the balance essentially iron with the proviso that the ratio of phosphorus to the sum of phosphorus, boron and carbon present is greater than or equal to 0.64.
Brief Description of the Drawings FIG. 1, on coordinates of potential and cur-rent density, is a plot of a typical curve for an active-passive alloy; and FIG. 2, on coordinates of potential and cur-rent density, is a plot of typical alloys of the inven-tion compared with prior art stainless steel and prior art glassy metal alloys.
Detailed Description of the Invention Potentiostatic anodic polarization measure-ments are performed by immersing a metallic electrode in an electrolyte solution and varying its potential in a stepwise manner with a special feedback power supply (i.e.l a potentiostat). If the current corresponding to each potential is recorded, an anodic polarization curve can be constructed. A typical curve for an active-passive alloy is shown in FIG. 1. Potential is 1 31 6~B85 ploted on the ordinate and the logarithm of the current density on the abscissa. The current density, which is equivalent to the alloy dissolution rate, at first in-creases with increasing potential (active region 10).
At more noble (positive) potentials, the dissolution - current density decreases and then remains at a low value (passive region 11). At very positive potentials, the dissolution rate again increases with increasing potential (transpassive region 12). The current maxi-mum which occurs at the primary passiv~ potential ~pp is termed the critical anodic current density Ic. The passive region beyins at the passive potential Ep and is characterized by the passive current density Ip Potentiostatic anodic polarization curves may be viewed as plots of solution oxidizing power (E) versus corrosion rate (current density). Thus, a typi-cal active-passive alloy possesses maximum corrosion resistance under moderately oxidiziny conditions. The corrosion resistance is lo~er under reducing conditions and in the presence of very strong oxidizers which cor-respond to the active and transpassive states, respec-tively. Passivation becornes easier as Epp becomes more negative and as Ic decreases. Therefore, it i5 possible to compare the ease of passivation of alloys on the basis of their anodic polarization curves, Also, corro-sion rates in the passive state can be directly compared on the basis of Ip values. Finally, the range of useful corrosion resistance can be estimated by noting the width of the passive region and the potential at whicn the transpassive region begins. Although actual anodic polarization curves sometimes deviate from the schematic illustration of FIG. 1, they can be compared on the same basis.
The corrosion resistant alloys of the inven-tion consist essentially of from about 0 to 18 atom per-cent nickel, from 7 to about 21 atom percent chromium, from 0 to about 8 atom percent molyb~enum, from about 13 to 18 atom percent of at least one element selected -~ 1 3 ~68~
froln the group consisting of phosphoru~, carbon and boron, other than phosphorus plus carbon, an~ the balance essentially iron with the proviso that the ratio of phosphorus to the sum o~ phosphorus~ carbon - 5 and boron is greater than or equal to 0.64.
Glassy metal alloys of the invention are forlned by cooling a melt of the desired composition at a rate of at least about 10 DC/sec. A variety of rapid quenching techniques, well known to the glassy metal alloy art, are available for producing glassy metal powders, wires, ribbon and sheet. Typically, a partic-ular composition is selected~ powders or granules of the requisite elements in the desired portions are melted and homogenized, and the molten alloy is rapidly quenched on a chill surface, such as a rapidly rotating cylinder, or in a suitable fluid medium, such as water.
Under these quenching conditions, a metastable, homo-geneous, ductile material is obtained. The metastable material may be amorphous or glassy, in which case there is no long range order. X-ray di~fraction patterns of glassy metal alloys show only a diffuse halo, similar to that observed for inorganic oxide glasses.
The amorphous metal alloys are at least 50%
amorphous, and preferably at least 80% amorphous, as measured by X-ray diffraction. However, a substantial degree of amorphousness approaching 100~ alrlorphous is obtained by forming these amorphous metal alloys in a partial vacuum. Ductility and corrosion resistance are thereby improved, and such alloys possessing a substan-tial degree of amorphousness are accordingly preferred.
Examples A number of iron-based glassy metal alloys were studied and compared with prior art glassy metal alloys and crystalline stainless steel alloys. Exposed electrode areas for as-cast glassy metal ribbons ranged from 0.3 to 1.0 cm . The ribbons were mounted (dull side out) on lucite rods. The plastic~lnetal interfaces were coated with lacquer to prevent crevice effects.
i 8 ~
-Stainless steel standards were in rod form wi~h ~n exposed area of about 5 cm2. The experiments were per-formed in nitrogen or hydrogen satura~ed electrolyte prepared from distilled water and reagent-grade chemi-cals. The electrodes were inserted into a Princeton Applied Research polarization cell and pre-exposed until the corrosion potential became nearly constant. Polari~
zation measurements were conducted in the noble direc-tion using a Potentiodyne. The scanning rate for glassy metal alloys was generally 1.5 V/hrO
Polarization curves for all alloys were obtained in lN H2S04 at 22C. Ma~erials exhibiting in-teresting charac~eristics were studied in other environments such as lN H2SO4 plus 5 percent NaCl, lON H2SO4, and 38 percent ~Cl. In addition, weight losses were determined in 6% FeC13 at 60C for 20 hours.
Ta'~le I compares alloy performance ln hydrogen-saturated 1~l E12SO4. Included are prior art crystalline and glassy metal alloys, as well as glassy metal alloys having compositions outside the scope of the invention.
1 6~6~
TABLE I
Values of IC ~ ~ 4 Composition, Atorn Percent Icc~2 Ip, 2 Fe Ni Cr P C B Other A/cm A/an Prior Art Crystalline Allo~s * 82 - 18 - - - - 4.0x10 2.4x10 ~* 72 8 20 - - - - 5.3x10 8.5x10 ***70 10 18 - - - 2 r~O 2.8x10 1.5x10 * 430 stainless steel ** 304 stainless steel *** 316 stainless steel Prior Art Amorphous Alloys 31.5 36 14.5 12.5 - 5.5 - 5.4x10 6 3.2x10 6 40 38 - 14 - 6 2Al Amorphous Alloys of This Invention _ -5 7 63. 7 - 20 16 - 0.3 - l.lx10 2.8x10 60. 7 - 21 18 - 0-3 ~ <1o-6 <1o-6 50. 217. 5 14 18 -` 0.3 - 9.0x10 7. 4xlO
60.2 - 14 18 _ 0.3 7.5 ~lo <10 7 <10-7 20 69.6 - 10 13 7 0. 4 - 1. 4xlO 8x10-7 59. 6 - 20 13 7 0. 4 - 1. lxlO 7 9. 5xlO 8 49.317.5 7 18 - 0.3 7.5 Mo <10 <10-7 Other ~rnorphous ~lloys 78.6 - 5 16 - 0.4 - 6.0xlO 4 5.8x10 5 25 74.7 - 7 18 - 0.3 - 2.8x10 3~6x10 6 73. 6 _ 10 16 - 0. 4 - 7. 6x10 5 2. 8xlO 6 72.1 2.5 5 13 7 0.4 - 6.9x10 4 3 . ox:L0~5 39.7 35 7 18 - 0.3 - 2.3x10 1.2x10 34 35.3 14 16 - 0.7 - 4.0x10 6 2.0x10 6 30 45.7 -- 21 17 -- 0.315 Mo Table II cornpares weiyht loss of alloys in 6 FeC13 at 60C for 20 hours. Again, prior art crystal-line and glassy metal alloys having compositions outside the scope of the invention are included for comparison.
5~BLE II
Dissolution of Alloys in . 6% FeCl , 60C, 20 hrs.
Alloy Con~osition, Atom Percent 10 Fe Ni Cr P C B Other % weight loss _ 72 - 20 ~ 6 18 - - - - 1.5 Prior ALt Amorphous Alloys 15 31.5 36 14.5 12.5 - 5.5 - 0 40 38 - 14 - 6 2Al Arnorphous Alloys of This Invention -63.7 - 20 16 - 0.3 - 0 60.7 - 21 18 - 0.3 - 0 2050.2 17.5 14 18 - 0.3 - 0 60.2 - 14 18 - 0~3 7.5 Mo 0 69.6 - 10 13 7 0.4 - 0 59.6 - 20 13 7 0.4 - 0 49.3 17.5 7 18 - 0.3 7.5 Mo 0 Other Amorpho~ Alloys 78.6 - 5 16 - 0.4 - 100 74.7 - 7 18 - 0.3 ~ 100 73.6 - 10 16 - 0.4 - 100 72.1 2.5 5 1?. 7 0.4 - 100 30 39.7 35 7 18 - 0.3 - 0 3435.3 14 16 - 0.7 - 0 45.7 - 21 18 - 0.3 15 .~o 0 On the basis of Ip values, the glassy metal alloys of the invention evidence values less than lx10 A/cm , with many values less than 10 A/c~n . Further, these alloys are stable in 6% Fe/C13. Alloys outside the invention are seen not to possess this combination of corros ion res is tance .
Having thus descri~ed the invention in rakher full detail~ it will be understood ~hat this detail need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all Ealling within the scope of the present : invention as defined by the subjoined claims.
,~ 10 ,';
Claims (3)
1. A metal alloy that is substantially glassy and resistant to corrosion in media over a wide range of oxidizing power consisting essentially of from about 0 to 18 atom percent nickel, from 7 to about 21 atom per-cent chromium, from 0 to about 8 atom percent molyb-denum, from about 16 to 18.3 atom percent of the element group phosphorus plus boron, and the balance essentially iron, with the provisos that the ratio of phosphorus to the sum of phosphorus and boron present is greater than or equal to 0.64 and the amount of Cr + Mo + 0.4 Ni is greater than or equal to 20 atom percent.
2. A metal alloy as recited in claim 1, having a formula consisting essentially of Fe50.2Ni17.5Cr14P18 B0.3.
3. A metal alloy as reclted in claim 1 having a formula consisting essentially of Fe60.2Cr14P18B0.3Mo7.5.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US8319879A | 1979-10-09 | 1979-10-09 | |
| US083,198 | 1979-10-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1164685A true CA1164685A (en) | 1984-04-03 |
Family
ID=22176805
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000361476A Expired CA1164685A (en) | 1979-10-09 | 1980-09-30 | Corrosion resistant glassy metal alloys |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0026863A1 (en) |
| JP (1) | JPS5662948A (en) |
| CA (1) | CA1164685A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU576431B2 (en) * | 1985-06-27 | 1988-08-25 | Standard Oil Company, The | Corrosion resistant amorphous ferrous alloys |
| CN115233118B (en) * | 2021-04-24 | 2023-03-10 | 江苏科晶智能科技股份有限公司 | Iron-nickel-chromium-based alloy, alloy foil made of same and preparation method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3856513A (en) * | 1972-12-26 | 1974-12-24 | Allied Chem | Novel amorphous metals and amorphous metal articles |
| GB1505841A (en) * | 1974-01-12 | 1978-03-30 | Watanabe H | Iron-chromium amorphous alloys |
-
1980
- 1980-09-19 EP EP80105612A patent/EP0026863A1/en not_active Withdrawn
- 1980-09-30 CA CA000361476A patent/CA1164685A/en not_active Expired
- 1980-10-09 JP JP14191180A patent/JPS5662948A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5662948A (en) | 1981-05-29 |
| EP0026863A1 (en) | 1981-04-15 |
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