US2357219A - Corrosion-resistant ferrous alloys - Google Patents
Corrosion-resistant ferrous alloys Download PDFInfo
- Publication number
- US2357219A US2357219A US426315A US42631542A US2357219A US 2357219 A US2357219 A US 2357219A US 426315 A US426315 A US 426315A US 42631542 A US42631542 A US 42631542A US 2357219 A US2357219 A US 2357219A
- Authority
- US
- United States
- Prior art keywords
- weight
- iron
- chromium
- article
- nickel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910000640 Fe alloy Inorganic materials 0.000 title description 4
- 238000005260 corrosion Methods 0.000 title description 2
- 230000007797 corrosion Effects 0.000 title description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 25
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 24
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 20
- 229910001220 stainless steel Inorganic materials 0.000 description 14
- 239000011651 chromium Substances 0.000 description 13
- 229910052804 chromium Inorganic materials 0.000 description 13
- 229910052742 iron Inorganic materials 0.000 description 13
- 229910052759 nickel Inorganic materials 0.000 description 13
- 239000010935 stainless steel Substances 0.000 description 13
- 229910052751 metal Inorganic materials 0.000 description 12
- 239000002184 metal Substances 0.000 description 12
- 239000000126 substance Substances 0.000 description 12
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 11
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 10
- 229910017604 nitric acid Inorganic materials 0.000 description 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 9
- 239000010941 cobalt Substances 0.000 description 9
- 229910017052 cobalt Inorganic materials 0.000 description 9
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 9
- 239000010936 titanium Substances 0.000 description 9
- 229910052719 titanium Inorganic materials 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 238000005498 polishing Methods 0.000 description 6
- 238000005266 casting Methods 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- 229910001510 metal chloride Inorganic materials 0.000 description 3
- VQLYBLABXAHUDN-UHFFFAOYSA-N bis(4-fluorophenyl)-methyl-(1,2,4-triazol-1-ylmethyl)silane;methyl n-(1h-benzimidazol-2-yl)carbamate Chemical compound C1=CC=C2NC(NC(=O)OC)=NC2=C1.C=1C=C(F)C=CC=1[Si](C=1C=CC(F)=CC=1)(C)CN1C=NC=N1 VQLYBLABXAHUDN-UHFFFAOYSA-N 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- QPJSUIGXIBEQAC-UHFFFAOYSA-N n-(2,4-dichloro-5-propan-2-yloxyphenyl)acetamide Chemical compound CC(C)OC1=CC(NC(C)=O)=C(Cl)C=C1Cl QPJSUIGXIBEQAC-UHFFFAOYSA-N 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229910000599 Cr alloy Inorganic materials 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000000788 chromium alloy Substances 0.000 description 1
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical class [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 1
- BIJOYKCOMBZXAE-UHFFFAOYSA-N chromium iron nickel Chemical compound [Cr].[Fe].[Ni] BIJOYKCOMBZXAE-UHFFFAOYSA-N 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hcl hcl Chemical compound Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F3/00—Brightening metals by chemical means
- C23F3/04—Heavy metals
- C23F3/06—Heavy metals with acidic solutions
Definitions
- the present invention relates to an improved method of polishing articles 'made of corrosionresistant ferrous alloys, and more particularly,
- the invention is applicable to the general class of iron-chromium alloys in which the alloying constituents are present in sufficient quantities to substantially passivize the iron, and more particularly to that group of chromium-nickel-iron alloys known as stainless steels, of which the commercial stainless steel known as 18-8 and containing 18% chromium, 8% nickel and the balance substantially all iron is representative.
- a smooth mirror finish on articles of the character described has been found to greatly reduce the corrosive action of chemicals on such surfaces. While it is possible to produce such a finish on articles which have all externally exposed surfaces by mechanical or anodic electrolytic polishing methods, such methods are of little practical value where the article has intricate internally exposed surfaces, such as frequently occur in complex castings of stainless steel.
- My invention is particularly useful in polishing such castings as the polishing treatment is simultaneously effective in removing scale and burnt-in sand from such castings, resulting in a complete resurfacing of the article and the production of a smooth cleanpassivated mirror finish.
- the articles to be treated are immersed in-a special chemical bath for a predetermined time, varying from a few sec: onds for thin sheets of stainlesssteel to about five minutes for relatively large intricate castings of stainless steel.
- the chemical bath preferably employed is a strong acidic solution having the following characteristics:
- Nitric acid HNOa
- Chromium .trioxide can be used instead of nitric acid'but is definitely not as eifectlve for my purposes; and
- the chloride of one or more of the following group of metals cobalt, nickel, iron, chromium or titanium, nickel or iron chloride being preferred in view of their low cost and availability. I have found that without on of these in the bath, the acid corrodent will not produce at the best more than. a silvery sheen on the exposed surfaces of the articles and never the desired mirror finish.
- Nitric acid 25 Hydrofluoric acid (HF) 15, Water (H20) 50 A chloride of one or more of the group Co,
- the bath should preferably be maintained at a temperature of from 180-200 F.
- the amount of hydrofluoric acid used should not be over 30% by weight, and preferably less than this value in view of the increasing violence of its action with the higher concentrations.
- the amount of metal chloride used should be within the range of 5-15% by weight of the solution.
- the bath may be made effective as a polishing bath in accordance with my invention by the addition of .the proper amount of hydrochloric acid (HCl) to form the corresponding metal chloride or chlorides.
- HCl hydrochloric acid
- the method of forming a smooth mirror finish on the exposed surfaces of a stainless steel article which comprises immersing the article in a chemical bath containing from 10 to 30% by weight of nitric acid, effective amounts up to 30% by weight of hydrofluoric acid, 5 to 15% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
- the method of forming a smooth mirror finish on the exposed surfaces of a stainless steel article which comprises immersing the article in a chemical bath containing-approximately 25% by weight of nitric acid, 15% by weight of hydrofluoric acid, by weight of a chloride of a metal selected from the'group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
- the method of forming-a smooth mirror finish on the "exposed surfaces of a stainless steel article which comprises immersing the article for a period of not more than five minutes in a chemical bath containing from 10 to 39% by weight of nitric acid, effective amounts up to 30% by weight of hydrofluoric acid, 5 to by weight, of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
- a stainless steel article which has been simultaneously chemically resurfaced to provide a mirror finish on its exposed surfaces and passivized by treatment in a bath containing from 10% to 30% by weight of nitric acid, eflective amounts up to 30% by weight of'hydrofiuoric acid, 5 to 15% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
- a stainless steel article which has been simultaneously chemically resurfaced to provide a mirror finish on its exposed surfaces and passivized by treatment in a bath containing approximately by weight of nitric acid, 15% by weight of hydrofluoric acid, 10% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
- a chemical bath for the treatment of stainless steel articles to provide a mirror finish thereon which contains from 10 to by weight of nitric acid, eifective amounts up to 30% by weight of hydrofluoric acid, 5 to 15% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and r' tanium, and the balance substantially all water.
- a chemical bath for the treatment of stainless steel articles to provide a mirror finish thereon which contains approximately 25% by weight of nitric acid, 15% by weight of hydrofluoric acid, 10% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- ing And Chemical Polishing (AREA)
Description
Patented Aug. 29,
CORROSION-RESISTANT FERROUS ALLOYS Norman S. Mott, Westfield, N. J., assignor of onehalf to Joseph P. Moran, Westfield, N. J.
No Drawing. Application January 10, 1942, Serial No. 426,315
8 Claims. (CLMHE) The present invention relates to an improved method of polishing articles 'made of corrosionresistant ferrous alloys, and more particularly,
to an improved method of chemically treating articles of corrosion-resistant ferrous alloys to produce not merely a lustre or sheen on the exposed surface of the article, but instead a mirror finish throughout the external and internal exposed surfaces of the article comparable to that produced on external exposed surfaces by mechanical or anodic electrolytic polishing.
The invention is applicable to the general class of iron-chromium alloys in which the alloying constituents are present in sufficient quantities to substantially passivize the iron, and more particularly to that group of chromium-nickel-iron alloys known as stainless steels, of which the commercial stainless steel known as 18-8 and containing 18% chromium, 8% nickel and the balance substantially all iron is representative.
A smooth mirror finish on articles of the character described has been found to greatly reduce the corrosive action of chemicals on such surfaces. While it is possible to produce such a finish on articles which have all externally exposed surfaces by mechanical or anodic electrolytic polishing methods, such methods are of little practical value where the article has intricate internally exposed surfaces, such as frequently occur in complex castings of stainless steel. My invention is particularly useful in polishing such castings as the polishing treatment is simultaneously effective in removing scale and burnt-in sand from such castings, resulting in a complete resurfacing of the article and the production of a smooth cleanpassivated mirror finish.
In my improved method the articles to be treated are immersed in-a special chemical bath for a predetermined time, varying from a few sec: onds for thin sheets of stainlesssteel to about five minutes for relatively large intricate castings of stainless steel. The chemical bath preferably employed is a strong acidic solution having the following characteristics:
1. There must be a substantial percentage of a highly active corrodent or attacking medium which tends to dissolv the metal surface uniformly rather than producing an etching efiect. I have found that hydrofluoric acid (HF) is most suitable for this purpose when in the presence of nitrioacid, and that it will give a uniform light silvery attack;
2. There must be present a large quantity of a constituent which will produce a strongly oxi dizing condition. Nitric acid (HNOa) is preferred for this purpose as it simultaneously produces passivation of the metal surface. Chromium .trioxide can be used instead of nitric acid'but is definitely not as eifectlve for my purposes; and
3. There must also be included in the chemical bath a lustre or sheen producing constituent,
and preferably the chloride of one or more of the following group of metals: cobalt, nickel, iron, chromium or titanium, nickel or iron chloride being preferred in view of their low cost and availability. I have found that without on of these in the bath, the acid corrodent will not produce at the best more than. a silvery sheen on the exposed surfaces of the articles and never the desired mirror finish.
For the best results I have found that a bath of the following composition is preferable:
Percent by weight Nitric acid (HNOa) 25 Hydrofluoric acid (HF) 15, Water (H20) 50 A chloride of one or more of the group Co,
Ni, Fe, Cr, or T1 10 The bath should preferably be maintained at a temperature of from 180-200 F.
While the formula given is indicative of the character of the chemical bath employed in the duce little or no polishing eifect. The amount of hydrofluoric acid used should not be over 30% by weight, and preferably less than this value in view of the increasing violence of its action with the higher concentrations. The amount of metal chloride used should be within the range of 5-15% by weight of the solution.
Where a HF-HNO: acid picklingbath contains nitrates or fluorides of the metals Co, Ni, Fe, Cr or Ti in sufllcient quantity, the bath may be made effective as a polishing bath in accordance with my invention by the addition of .the proper amount of hydrochloric acid (HCl) to form the corresponding metal chloride or chlorides.
It will be understood that the particular solutions described are given as examples of chemical baths which wholly or partly accomplish'the desired result of producing stainless steel articles having a smooth clean mirror finish on all of its external and internai surfaces. The scope of the invention is indicated. by the appended 1 of a metal selected from the group consisting of claims rather than by the foregoing description,
and all variations in ingredients falling within the range of equivalency of the claims are intended to be embraced therein.
,1 claim:
1. The method of forming a smooth mirror finish on the exposed surfaces of a stainless steel article which comprises immersing the article in a chemical bath containing from 10 to 30% by weight of nitric acid, effective amounts up to 30% by weight of hydrofluoric acid, 5 to 15% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
2. The method of forming a smooth mirror finish on the exposed surfaces of a stainless steel article which comprises immersing the article in a chemical bath containing-approximately 25% by weight of nitric acid, 15% by weight of hydrofluoric acid, by weight of a chloride of a metal selected from the'group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
3. The method of forming-a smooth mirror finish on the "exposed surfaces of a stainless steel article which comprises immersing the article for a period of not more than five minutes in a chemical bath containing from 10 to 39% by weight of nitric acid, effective amounts up to 30% by weight of hydrofluoric acid, 5 to by weight, of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
4. The method of forming a smooth mirror finish on the exposed surfaces of a stainless steel article which comprises immersing the article for a period of not morethan five minutes in a chemical bath at a temperature of from 180200 F.
' and containing from 10 to 30% by weight of nitric cobalt, nickel, iron,.chromium and titanium, and the balance substantially all water.
5. A stainless steel article which has been simultaneously chemically resurfaced to provide a mirror finish on its exposed surfaces and passivized by treatment in a bath containing from 10% to 30% by weight of nitric acid, eflective amounts up to 30% by weight of'hydrofiuoric acid, 5 to 15% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
6. A stainless steel article which has been simultaneously chemically resurfaced to provide a mirror finish on its exposed surfaces and passivized by treatment in a bath containing approximately by weight of nitric acid, 15% by weight of hydrofluoric acid, 10% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
7. A chemical bath for the treatment of stainless steel articles to provide a mirror finish thereon which contains from 10 to by weight of nitric acid, eifective amounts up to 30% by weight of hydrofluoric acid, 5 to 15% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and r' tanium, and the balance substantially all water.
8. A chemical bath for the treatment of stainless steel articles to provide a mirror finish thereon which contains approximately 25% by weight of nitric acid, 15% by weight of hydrofluoric acid, 10% by weight of a chloride of a metal selected from the group consisting of cobalt, nickel, iron, chromium and titanium, and the balance substantially all water.
NORMAN S. MO'I'I'.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US426315A US2357219A (en) | 1942-01-10 | 1942-01-10 | Corrosion-resistant ferrous alloys |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US426315A US2357219A (en) | 1942-01-10 | 1942-01-10 | Corrosion-resistant ferrous alloys |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2357219A true US2357219A (en) | 1944-08-29 |
Family
ID=23690283
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US426315A Expired - Lifetime US2357219A (en) | 1942-01-10 | 1942-01-10 | Corrosion-resistant ferrous alloys |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2357219A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2507956A (en) * | 1947-11-01 | 1950-05-16 | Lithographic Technical Foundat | Process of coating aluminum |
| US2576680A (en) * | 1945-09-15 | 1951-11-27 | Electro Chimie Metal | Method for increasing the resistance to corrosion of stainless steel |
| US2817610A (en) * | 1955-05-26 | 1957-12-24 | Isaac L Newell | Method for the production of black oxide coatings on steel and iron and composition therefor |
| US2837407A (en) * | 1955-07-08 | 1958-06-03 | Rau Eric | Method of reducing metallic corrosion by fuming nitric acid by addition of fluoride ion to acid |
| US2847371A (en) * | 1955-06-28 | 1958-08-12 | Tiarco Corp | Chromium plating on aluminum |
| US2851385A (en) * | 1952-04-03 | 1958-09-09 | Amchem Prod | Process and composition for coating aluminum surfaces |
| US3213008A (en) * | 1961-06-14 | 1965-10-19 | Ametek Inc | Electrolytic polishing of stainless steel |
| US3505129A (en) * | 1967-01-16 | 1970-04-07 | Hooker Chemical Corp | Chemical coating process for metal |
| US3539402A (en) * | 1967-02-16 | 1970-11-10 | Collardin Gmbh Gerhard | Solutions for the deposition of protective surface layers on iron and zinc and process therefor |
| US4776898A (en) * | 1985-03-20 | 1988-10-11 | Omi International Corporation | Passivation |
| US6150040A (en) * | 1997-05-15 | 2000-11-21 | Jgc Corporation | Pure steam-related apparatus protected from fouling and method of manufacturing the same |
-
1942
- 1942-01-10 US US426315A patent/US2357219A/en not_active Expired - Lifetime
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2576680A (en) * | 1945-09-15 | 1951-11-27 | Electro Chimie Metal | Method for increasing the resistance to corrosion of stainless steel |
| US2507956A (en) * | 1947-11-01 | 1950-05-16 | Lithographic Technical Foundat | Process of coating aluminum |
| US2851385A (en) * | 1952-04-03 | 1958-09-09 | Amchem Prod | Process and composition for coating aluminum surfaces |
| US2817610A (en) * | 1955-05-26 | 1957-12-24 | Isaac L Newell | Method for the production of black oxide coatings on steel and iron and composition therefor |
| US2847371A (en) * | 1955-06-28 | 1958-08-12 | Tiarco Corp | Chromium plating on aluminum |
| US2837407A (en) * | 1955-07-08 | 1958-06-03 | Rau Eric | Method of reducing metallic corrosion by fuming nitric acid by addition of fluoride ion to acid |
| US3213008A (en) * | 1961-06-14 | 1965-10-19 | Ametek Inc | Electrolytic polishing of stainless steel |
| US3505129A (en) * | 1967-01-16 | 1970-04-07 | Hooker Chemical Corp | Chemical coating process for metal |
| US3539402A (en) * | 1967-02-16 | 1970-11-10 | Collardin Gmbh Gerhard | Solutions for the deposition of protective surface layers on iron and zinc and process therefor |
| US4776898A (en) * | 1985-03-20 | 1988-10-11 | Omi International Corporation | Passivation |
| US6150040A (en) * | 1997-05-15 | 2000-11-21 | Jgc Corporation | Pure steam-related apparatus protected from fouling and method of manufacturing the same |
| EP0878662A3 (en) * | 1997-05-15 | 2001-04-11 | Jgc Corporation | Pure steam-related apparatus protected from fouling and method of manufacturing the same |
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