CA1138816A - Protecting ferritic stainless steel from crevice and pitting corrosion - Google Patents
Protecting ferritic stainless steel from crevice and pitting corrosionInfo
- Publication number
- CA1138816A CA1138816A CA000328402A CA328402A CA1138816A CA 1138816 A CA1138816 A CA 1138816A CA 000328402 A CA000328402 A CA 000328402A CA 328402 A CA328402 A CA 328402A CA 1138816 A CA1138816 A CA 1138816A
- Authority
- CA
- Canada
- Prior art keywords
- stainless steel
- ferritic
- dissimilar
- pitting corrosion
- crevice
- 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
Links
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
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Prevention Of Electric Corrosion (AREA)
- Physical Vapour Deposition (AREA)
- Arc Welding In General (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for protecting ferritic stainless steel against crevice and pitting corrosion in an environment corrosive thereto. The ferratic stainless steel is protected against crevice and pitting corrosion by covering a portion thereof with another stainless steel which is less noble than the ferritic steel in the referred to corrosive environment.
A process for protecting ferritic stainless steel against crevice and pitting corrosion in an environment corrosive thereto. The ferratic stainless steel is protected against crevice and pitting corrosion by covering a portion thereof with another stainless steel which is less noble than the ferritic steel in the referred to corrosive environment.
Description
1 PROTECTING ~ERRITIC STAINLESS STEEL FROM
. _ .
CREVICE AND PITTING CORROSION
~BSTRACT OF T~E DISCLOSURE
A process for protecting ferritic stainless steel against crevice and pitting corrosion in an environment corrosive thereto. The ferritic stainless steel is ~protected against crevice and pitting corrosion by covering a portion thereof with another stainless steel which is less noble than the ferritic steel in the referred to ~orrosive environment.
1~
The present invention relates to ~ process or protecting ferritic stainless ste~ls against crevice and pitting ~orrosion.
Although ferritic stainless steels are excellent ~aterial considerations for water containing vessels, chloride and ~ineral contamination in some waters is sufficiently high to promDte crevice and pitting corrosion. This is especially true in 301ar ~bsorber panels which are characterîzed by severe ~reviees.
Through the present invention, there is now provided an i~proved Deans for protecting ferritic stainless steel from crevice and pitting corrosion. The ferritic stainless steel is protected by covering a portion thereof with another stainless steel ~hich is less noble than the ferritic steel ~n the corrosive ænvironment.
Design engineers have ~tte~pted to protect ferritic ~tainless ~teels from ~revi~e and pitting corrosion by covering ~L~.3~
:
1 portions thereof wi~h a dissimilar class of metal. United States Patent No. 3,830t7~0 discloses a process wherein aluminum i5 used to protect stainless steel. The aluminum forms the cover of a sacrificial anode. The core of the anode is stainless S steel. ~s the stainless steel core is of the same ~he~istry as the stainless ~teel to which lt is attached, the patent does not disclose a process wherein ferritic stainless steel is protected by a dissimilar stainless steel.
Many other references deal with galvanic reactions.
These references include United States Patent Nos. 1,613,461,
. _ .
CREVICE AND PITTING CORROSION
~BSTRACT OF T~E DISCLOSURE
A process for protecting ferritic stainless steel against crevice and pitting corrosion in an environment corrosive thereto. The ferritic stainless steel is ~protected against crevice and pitting corrosion by covering a portion thereof with another stainless steel which is less noble than the ferritic steel in the referred to ~orrosive environment.
1~
The present invention relates to ~ process or protecting ferritic stainless ste~ls against crevice and pitting ~orrosion.
Although ferritic stainless steels are excellent ~aterial considerations for water containing vessels, chloride and ~ineral contamination in some waters is sufficiently high to promDte crevice and pitting corrosion. This is especially true in 301ar ~bsorber panels which are characterîzed by severe ~reviees.
Through the present invention, there is now provided an i~proved Deans for protecting ferritic stainless steel from crevice and pitting corrosion. The ferritic stainless steel is protected by covering a portion thereof with another stainless steel ~hich is less noble than the ferritic steel ~n the corrosive ænvironment.
Design engineers have ~tte~pted to protect ferritic ~tainless ~teels from ~revi~e and pitting corrosion by covering ~L~.3~
:
1 portions thereof wi~h a dissimilar class of metal. United States Patent No. 3,830t7~0 discloses a process wherein aluminum i5 used to protect stainless steel. The aluminum forms the cover of a sacrificial anode. The core of the anode is stainless S steel. ~s the stainless steel core is of the same ~he~istry as the stainless ~teel to which lt is attached, the patent does not disclose a process wherein ferritic stainless steel is protected by a dissimilar stainless steel.
Many other references deal with galvanic reactions.
These references include United States Patent Nos. 1,613,461,
2,303,778, 2,619,455, 3,084,742, 3,378,359, 3,616,416 and
3,830,634. None of them provide a process wherein a dissimilar stainless steel is used to protect a ferritic stainless st~el.
By utilizing a dissi~ilar stainless steel, the present invention prolongs the life of the sacrificial metal and reduces the amount of contaminating corrosion products.
It is accordingly an object of the present invention to provide a process for protecting ferritic stainless steel against crevice and pitting corrosion.
The present invention sets forth a process for protecting erritic stainless steel against crevice and pitting corrosion in an environment corrosive thereto. It comprises the steps of providing ~ ferritic stainless steel substrate and covering 6eparate portions of one surface ~f ~he substrate with a dissimilar stainless steel which is less noble than the ferritic stainless ~teel in the referred to corrosive environment. The corrosive environment is generally a ~hloride-bearing environment~ It ~ould ~lso be ~n environment ~hich is ~ulfide-bearing or caustic.
.3~
1 The ~hoice ~f the dissi~ilar ~tainless ~teel is dependent upon a determination of the environment to which the ferritic stainless steel ~s ~o be subjected. The dissimilar stainless steel can be attached o the ferritic stainless ~teel in a variety of ways which`include welding, pressure bonding, Yiveting ~nd spraying.
~he steels must be ~$~eh~ so as to provide $ntimate electrical contact.
The article of the present invention is characterized by a ferritic stainless steel substrate and dissimilar stainless steel attached thereto. The dissimilar stainless steel covers separate por~ions of one surface of the subs~rate, and is as described hereinabove. As noted in the examples appearing hereinbelow, A.I.S.I. Type 409 stainless steel can be the dissimilar steel used in conjunction with A.I.5.I. ~ype 439 stainless steel. The article ~an be formed and welded into various vessels such as solar absorber panels and hot water tanks. Alternatively, the dissimilar stainless steel can be ~ttached to the ~erritic stainless steel during or subsequent to fabrication. The dissimilar stainless steel constitutes a portion of the inner surface of the finished vessel~
The following examples are illustrative of several aspects of the invention.
To demonstrate the present ~nvention, a co~posite was ~ade by spot welding an A.l.S.I. Type 409 specimen between two ~5 A.I.S.I. Type 439 specimens. Type 409 ~tainless ~teel is less noble ln chloride-bearing environments than is Type 439 stainless steel~ An additional co~posite was ~ade using ~luminum in place of the 409 stainless ~teel. As discussed hereinabsve, aluminum 1 has been used to protect ferritic stainless steels from crevice and pitting corrosion.
The co~posites were placed in hot water at a temperature of 180F. Sodium chloride was added to the water to provide a ~hloride ion concentration of 1000 ppm. After 8 ~eeks the 439 having the 409 welded thereto was basically in as good a condition ~s was the 439 having the aluminum welded thereto. The weight loss for the 439-409-43~ composite was, however, significantly less than that for the 439-Al-439 ~omposite. The percent loss was 0.38~ for the 409 composite and 1.01~ for the composite having aluminum. Significantly, the present invention provides an advantageous means for protecting ferritic stainless steel from crevice and pitting corrosion.
It will be ~pparent to those skilled in the art that the novel principles of the invention disclosed herein in connection with specific examples thereof will suggest various other modifications and applications of the same. It is accordingly desired that in construing the breadth of the appended claims they shall not be limited to the specific examples of the invention described herein.
By utilizing a dissi~ilar stainless steel, the present invention prolongs the life of the sacrificial metal and reduces the amount of contaminating corrosion products.
It is accordingly an object of the present invention to provide a process for protecting ferritic stainless steel against crevice and pitting corrosion.
The present invention sets forth a process for protecting erritic stainless steel against crevice and pitting corrosion in an environment corrosive thereto. It comprises the steps of providing ~ ferritic stainless steel substrate and covering 6eparate portions of one surface ~f ~he substrate with a dissimilar stainless steel which is less noble than the ferritic stainless ~teel in the referred to corrosive environment. The corrosive environment is generally a ~hloride-bearing environment~ It ~ould ~lso be ~n environment ~hich is ~ulfide-bearing or caustic.
.3~
1 The ~hoice ~f the dissi~ilar ~tainless ~teel is dependent upon a determination of the environment to which the ferritic stainless steel ~s ~o be subjected. The dissimilar stainless steel can be attached o the ferritic stainless ~teel in a variety of ways which`include welding, pressure bonding, Yiveting ~nd spraying.
~he steels must be ~$~eh~ so as to provide $ntimate electrical contact.
The article of the present invention is characterized by a ferritic stainless steel substrate and dissimilar stainless steel attached thereto. The dissimilar stainless steel covers separate por~ions of one surface of the subs~rate, and is as described hereinabove. As noted in the examples appearing hereinbelow, A.I.S.I. Type 409 stainless steel can be the dissimilar steel used in conjunction with A.I.5.I. ~ype 439 stainless steel. The article ~an be formed and welded into various vessels such as solar absorber panels and hot water tanks. Alternatively, the dissimilar stainless steel can be ~ttached to the ~erritic stainless steel during or subsequent to fabrication. The dissimilar stainless steel constitutes a portion of the inner surface of the finished vessel~
The following examples are illustrative of several aspects of the invention.
To demonstrate the present ~nvention, a co~posite was ~ade by spot welding an A.l.S.I. Type 409 specimen between two ~5 A.I.S.I. Type 439 specimens. Type 409 ~tainless ~teel is less noble ln chloride-bearing environments than is Type 439 stainless steel~ An additional co~posite was ~ade using ~luminum in place of the 409 stainless ~teel. As discussed hereinabsve, aluminum 1 has been used to protect ferritic stainless steels from crevice and pitting corrosion.
The co~posites were placed in hot water at a temperature of 180F. Sodium chloride was added to the water to provide a ~hloride ion concentration of 1000 ppm. After 8 ~eeks the 439 having the 409 welded thereto was basically in as good a condition ~s was the 439 having the aluminum welded thereto. The weight loss for the 439-409-43~ composite was, however, significantly less than that for the 439-Al-439 ~omposite. The percent loss was 0.38~ for the 409 composite and 1.01~ for the composite having aluminum. Significantly, the present invention provides an advantageous means for protecting ferritic stainless steel from crevice and pitting corrosion.
It will be ~pparent to those skilled in the art that the novel principles of the invention disclosed herein in connection with specific examples thereof will suggest various other modifications and applications of the same. It is accordingly desired that in construing the breadth of the appended claims they shall not be limited to the specific examples of the invention described herein.
-4
Claims (6)
1. A process for producing a vessel of ferritic stain-less steel which is protected against crevice and pitting corrosion in an environment corrosive thereto, which process comprises the steps of: providing a ferritic stainless steel substrate and covering separate portions of one surface of said substrate with a dissimilar stainless steel, said dis-similar stainless steel being less noble than said ferritic stainless steel in said corrosive environment, said dissimilar stainless steel being in electrical contact with said ferritic stainless steel and forming said ferritic stainless steel into a vessel suitable for containing a liquid medium, said dissimilar stainless steel being on the inner surface of the vessel.
2. A process according to claim 1, wherein said ferritic stainless steel is an A.I.S.I. Type 439 stainless steel.
3. A process according to claim 2, wherein said dissimilar stainless steel is an A.I.S.I. Type 409 stainless steel.
4. A vessel shaped article comprising a ferritic stain-less steel substrate and a dissimilar stainless steel attached thereto so as to the in electrical contact therewith, said dissimilar stainless steel covering separate portions of the inner surface of said substrate, said dissimilar stainless steel improving the crevice and pitting corrosion resistance of said ferritic stainless steel in an environment corrosive thereto, said dissimilar stainless steel being less noble than said fer-ritic stainless steel in said corrosive environment.
5. An article according to claim 4, wherein said ferritic stainless steel is an A.I.S.I. Type 439 stainless steel.
6. An article according to claim 4, wherein dissimilar stainless steel is an A.I.S.I. Type 409 stainless steel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US91341478A | 1978-06-07 | 1978-06-07 | |
| US913,414 | 1978-06-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1138816A true CA1138816A (en) | 1983-01-04 |
Family
ID=25433252
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000328402A Expired CA1138816A (en) | 1978-06-07 | 1979-05-25 | Protecting ferritic stainless steel from crevice and pitting corrosion |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS54159349A (en) |
| AT (1) | AT364892B (en) |
| AU (1) | AU528375B2 (en) |
| BR (1) | BR7903481A (en) |
| CA (1) | CA1138816A (en) |
| DE (1) | DE2922950C2 (en) |
| ES (1) | ES481333A1 (en) |
| FR (1) | FR2428082A1 (en) |
| GB (1) | GB2022614B (en) |
| IL (1) | IL57328A (en) |
| IT (1) | IT1116242B (en) |
| SE (1) | SE7904909L (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101487626B (en) * | 2008-01-15 | 2012-03-07 | Lg电子株式会社 | Fan support bench of outdoor unit |
| JP2018194216A (en) | 2017-05-16 | 2018-12-06 | 三菱重工サーマルシステムズ株式会社 | Outdoor equipment of air conditioning system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2303778A (en) * | 1941-02-06 | 1942-12-01 | Int Nickel Co | Soil pipe |
| FR1062216A (en) * | 1952-02-13 | 1954-04-21 | United States Steel Corp | Double metal material |
| FR1216918A (en) * | 1957-07-05 | 1960-04-29 | Inst Francais Du Petrole | Steel protection process |
| DE2422513C3 (en) * | 1974-05-09 | 1978-06-22 | Elpag Ag Chur, Chur (Schweiz) | Tubular heater |
-
1979
- 1979-05-16 AU AU47129/79A patent/AU528375B2/en not_active Ceased
- 1979-05-18 GB GB7917377A patent/GB2022614B/en not_active Expired
- 1979-05-18 IL IL57328A patent/IL57328A/en unknown
- 1979-05-25 CA CA000328402A patent/CA1138816A/en not_active Expired
- 1979-06-04 BR BR7903481A patent/BR7903481A/en unknown
- 1979-06-06 SE SE7904909A patent/SE7904909L/en not_active Application Discontinuation
- 1979-06-06 ES ES481333A patent/ES481333A1/en not_active Expired
- 1979-06-06 IT IT49332/79A patent/IT1116242B/en active
- 1979-06-06 DE DE2922950A patent/DE2922950C2/en not_active Expired
- 1979-06-07 AT AT0409979A patent/AT364892B/en not_active IP Right Cessation
- 1979-06-07 FR FR7914627A patent/FR2428082A1/en not_active Withdrawn
- 1979-06-07 JP JP7182579A patent/JPS54159349A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| BR7903481A (en) | 1980-01-15 |
| IL57328A0 (en) | 1979-09-30 |
| FR2428082A1 (en) | 1980-01-04 |
| AU4712979A (en) | 1979-12-13 |
| DE2922950A1 (en) | 1979-12-13 |
| GB2022614B (en) | 1983-01-12 |
| SE7904909L (en) | 1979-12-08 |
| IT7949332A0 (en) | 1979-06-06 |
| IT1116242B (en) | 1986-02-10 |
| ES481333A1 (en) | 1980-08-16 |
| ATA409979A (en) | 1981-04-15 |
| DE2922950C2 (en) | 1983-08-04 |
| AU528375B2 (en) | 1983-04-28 |
| GB2022614A (en) | 1979-12-19 |
| JPS54159349A (en) | 1979-12-17 |
| AT364892B (en) | 1981-11-25 |
| IL57328A (en) | 1982-09-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Copson et al. | Effect of contaminants on resistance to stress corrosion cracking of Ni-Cr alloy 600 in pressurized water | |
| AU9824998A (en) | Passivation of stainless steels in organosulphonic acid medium | |
| PL194765B1 (en) | Oxidation and corrosion resistant austenitic stainless steel including molybdenum | |
| Satoh et al. | The crevice corrosion resistance of some titanium materials | |
| CA1138816A (en) | Protecting ferritic stainless steel from crevice and pitting corrosion | |
| JPS63186883A (en) | Zinc plated steel sheet having superior spot weldability | |
| JPS6058161B2 (en) | Flexible layered graphite material and its manufacturing method | |
| Fukuzuka et al. | Corrosion problems and their preventions of MSF desalination plant constructed with titanium tube | |
| CA1138815A (en) | Protecting austenitic stainless steel from stress corrosion cracking | |
| KR820001547B1 (en) | Protecting feritic stainless steel from crevice and pitting corrosion | |
| KR820001548B1 (en) | Protecting austenitic stainless steel from corrosion cracking | |
| Spacht | The corrosion resistance of aluminum and its alloys. | |
| Wong et al. | Corrosion Characteristics of Titanium Alloys in Multi-Ionic Environments | |
| GB2076432A (en) | Cu-Ni coatings on ferrous substrates | |
| US4178990A (en) | Solar energy collector system | |
| US2172388A (en) | Stainless steel | |
| DAGDAG | An Overview of Corrosion | |
| GB1558623A (en) | Protection from corrosion of steel equipment in which alkali metal hydroxide solutions are handled | |
| Roy et al. | Galvanic Corrosion-Effect of Environmental and Experimental Variables | |
| JPH0357571A (en) | Structure of resistance weld zone of stainless steel | |
| AILOR JR | A Review of Aluminum Corrosion in Tap Waters | |
| Rideout et al. | Factors Controlling chloride stress corrosion of type 304 stainless steel | |
| JPH045753B2 (en) | ||
| Singh | Various forms of water side Corrosion: Causes & Prevention | |
| JPS6012419B2 (en) | Corrosion-resistant structural steel for seawater desalination plants by flash distillation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |