US3385734A - Process and composition for pickling steel - Google Patents
Process and composition for pickling steel Download PDFInfo
- Publication number
- US3385734A US3385734A US415493A US41549364A US3385734A US 3385734 A US3385734 A US 3385734A US 415493 A US415493 A US 415493A US 41549364 A US41549364 A US 41549364A US 3385734 A US3385734 A US 3385734A
- Authority
- US
- United States
- Prior art keywords
- percent
- pickling
- steel
- water
- bath
- 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
- 238000005554 pickling Methods 0.000 title claims description 32
- 238000000034 method Methods 0.000 title claims description 10
- 229910000831 Steel Inorganic materials 0.000 title description 17
- 239000010959 steel Substances 0.000 title description 17
- 239000000203 mixture Substances 0.000 title description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 24
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 239000012141 concentrate Substances 0.000 claims description 13
- 239000002202 Polyethylene glycol Substances 0.000 claims description 5
- 229920001223 polyethylene glycol Polymers 0.000 claims description 5
- BBMHARZCALWXSL-UHFFFAOYSA-M sodium dihydrogenphosphate monohydrate Chemical compound O.[Na+].OP(O)([O-])=O BBMHARZCALWXSL-UHFFFAOYSA-M 0.000 claims description 5
- 238000007865 diluting Methods 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- XLYOFNOQVPJJNP-PWCQTSIFSA-N Tritiated water Chemical compound [3H]O[3H] XLYOFNOQVPJJNP-PWCQTSIFSA-N 0.000 claims 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 12
- 239000002253 acid Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 7
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 4
- 235000003891 ferrous sulphate Nutrition 0.000 description 4
- 239000011790 ferrous sulphate Substances 0.000 description 4
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 4
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000000536 complexating effect Effects 0.000 description 2
- 239000003517 fume Substances 0.000 description 2
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 239000003643 water by type Substances 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 239000003317 industrial substance Substances 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000002195 synergetic effect Effects 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
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/08—Iron or steel
Definitions
- Sulfuric acid pickling entails certain disadvantages.
- the oxides of mill scale are converted to ferrous sulfate which builds up in the pickling liquor, and a high concentration of that salt at the disharge end of the pickling tank is detrimental to the pickling operation.
- the disposal of spent acid presents major problems.
- the spent liquor may contain as much as 5 percent of free acid and as much as percent of ferrous sulfate. Obviously, such a solution cannot be dumped into streams, lakes or other natural waters.
- the free acid may be new tralized, as with lime, and the ferrous sulfate may be removed by concentration of the spent liquor to cause deposidon of the salt, to prepare the liquor for harmless discharge into natural waters.
- Another object is to provide a novel hydrochloric acid pickling bath for practicing the foregoing method, which embodies an inhibiting agent and an agent for complexing the iron chloride resulting from the action of the pickling solution.
- Still another object is to provide a concentrate for making baths in accordance with the invention.
- a pickling concentrate comprising a solution of, by weight about 80 to 85 percent of B. hydrochloric acid (average 31.4 percent HCl), and about 10 to 15 percent of ice added water, about 1 to 3 percent of sodium dihydrogen phosphate monohydrate, about 0.5 to 1.5 percent of water soluble polyethylene glycol. and about 0.2 to 1.5 percent of monoethanolamine.
- the concentrate provided by the invention rriay be used to form the bath by dilution with water and thus avoid the necessity of shipping the large quantities of water to the steel plant if the bath were to be made up ready for use and shipped to the point of use.
- the concentrate of this invention is blended with about 5 to 15 parts of 20 B. HCl and then diluted with water either by the addition of water or by the condensation of steam used to heat the bath, so that the most concentrated tank of the pickling line, from which the steel exits, will contain about 10 to 15 percent of HCl.
- the other tanks of the line will contain varying amounts of acid, depending on the number of tanks, the rate of travel of the steel strip, bath temperature, and related factors. The actual concentration of acid is maintained by the operators according to plant conditions by addition of the concentrate.
- the polyethylene glycol serves, we now believe, to increase the solubility in concentrated hydrochloric acid of the phosphate salt and thus permits the formulation of the concentrate that characterizes this invention and which in turn avoids the shipment of large quantities of water.
- a polyethylene glycol such as one of about 6,000 average molecular weight, which is a waxy solid at room temperature.
- the monoethanolamine may be replaced by diethanolamine or triethanolamine, and mixtures of any two or all three of them may be used likewise.
- the phosphate specified for the bath it may be supplied to the concentrate as sodium chloride and orthophosphoric acid in amounts equivalent to the specified amount of sodium dihydrogen phosphate monohydrate.
- pickling equipment is used in the practice of this invention. There is nothing critical in the temperature of the bath but generally it should range from about F. to not over about 210 F.
- the pickled strip is treated conventionally by subjecting it to a cold water spray followed by a hot water spray and then flash drying it at about 230 F.
- the steel moves countercurrently to the direction of fiow of the pickling liquor with makeup acid being supplied by concentrate added at the end of the tank from which the strip exits.
- a pickling bath concentrate consisting essentially of, by weight, about to percent of 20 B. hydrochloric acid and about 10 to 15 percent additional water, about 1 to 3 percent of sodium dihydrogen phosphate monohydrate, about 0.5 to 1.5 percent of polyethylene glycol, and about 0.2 to 1.5 percent of at least one ethanolamine, diluting the blend with water to about 8 to 15 percent of HCl, and passing the steel through the resultant bath.
Description
United States Patent O 3,385,734 PROCESS AND COMPOSITION FOR PICKLING STEEL Lloyd B. Barkley, Pittsburgh, and Robert G. Buckingham, Finleyville, Pa., assignors to Pennsylvania Industrial Chemical Corporation, a corporation of Pennsylvania No Drawing. Filed Dec. 2, 1964, Ser. No. 415,493 5 Claims. (Cl. 134--3) In the production of cold reduced strip steel it is necessary that the oxides, commonly called mill scale, that form during hot rolling be removed to prepare the strip for further processing, for instance by drawing operations or to condition the strip to receive various types of surface coatings. For many years this has been accomplished by pickling the hot rolled strip in solutions of sulfuric acid. In that practice the hot rolled material is passed through a tank, or a series of tanks, called a pickling line, countercurrent to the movement of the pickling solution, with strong fresh acid being added to the end of the pickling line where the steel exits.
Sulfuric acid pickling entails certain disadvantages. For instance, the oxides of mill scale are converted to ferrous sulfate which builds up in the pickling liquor, and a high concentration of that salt at the disharge end of the pickling tank is detrimental to the pickling operation. Moreover, the disposal of spent acid presents major problems. The spent liquor may contain as much as 5 percent of free acid and as much as percent of ferrous sulfate. Obviously, such a solution cannot be dumped into streams, lakes or other natural waters. The free acid may be new tralized, as with lime, and the ferrous sulfate may be removed by concentration of the spent liquor to cause deposidon of the salt, to prepare the liquor for harmless discharge into natural waters. Such procedures are expensive, and even if the spent liquor merely be discharged into sumps the necessary land represents a cost burden and there is danger that the acid and sulfate will percolate and render ground waters useless. The ferrous sulfate content of spent liquor represents an economic loss but its recovery as such or its conversion to iron oxide are not justified because of their low market value.
Pickling with hydrochloric acid has been proposed and tried but although it has found limited use in the batch pickling of steel sheet and plate, it has not supplanted sulfuric acid in continuous strip pickling lines. One reason for this is that the fumes given off during hydrochloric acid pickling are highly objectionable to workmen and create an atmosphere that corrodes metallic equipment.
It is among the objects of this invention to provide a method of pickling steel with hydrochloric acid in the practice of which fuming is suppressed to a low level, which is productive of a bright and white surface the irregularities of which are much less pronounced than those produced by sulfuric acid, which results in lower residual surface chloride as compared with other pickling methods, and which is adapted particularly to continuous operation with conventional pickling equipment.
Another object is to provide a novel hydrochloric acid pickling bath for practicing the foregoing method, which embodies an inhibiting agent and an agent for complexing the iron chloride resulting from the action of the pickling solution.
Still another object is to provide a concentrate for making baths in accordance with the invention.
Other objects will be recognized from the following description.
In accordance with this invention there is provided a pickling concentrate comprising a solution of, by weight about 80 to 85 percent of B. hydrochloric acid (average 31.4 percent HCl), and about 10 to 15 percent of ice added water, about 1 to 3 percent of sodium dihydrogen phosphate monohydrate, about 0.5 to 1.5 percent of water soluble polyethylene glycol. and about 0.2 to 1.5 percent of monoethanolamine.
We have found that these composidons when diluted with water to about 10 to 15 percent HCl concentration not ony effect rapid removal of mill scale but also exert a combination of other desirable functions, presumably through synergistic action. Since the steel is not attacked the problem of hydrogen evolution with H 80 pickling is avoided. The solutions attack the scale in such manner that the use of scale breakers is unnecessary. The steel has a bright surface with no dark deposit. Of particular advantage is the fact that the surface is very much smoother than is obtained with sulfuric acid pickling. Measurement of surface irregularities of strip steel pickled in accordance with this invention shows that they average about to microns as compared with to micron irregularities at the surface of sulfuric acid pickled steel. Furthermore, after the strip has been washed there is no detectable chloride at the surface.
In addition to these advantages there is very low fume level in the vicinity of the pickling tank, which is particularly desirable from the standpoint of labor relations and also reduced attack of neighboring metal equipment. This we believe to be due to an inhibiting action of the ethanolamine. The phosphate content of these solutions exerts a complexing action upon the iron chloride formed and insures the formation of a bright finish.
An important feature of the invention is that the concentrate provided by the invention rriay be used to form the bath by dilution with water and thus avoid the necessity of shipping the large quantities of water to the steel plant if the bath were to be made up ready for use and shipped to the point of use. In practice the concentrate of this invention is blended with about 5 to 15 parts of 20 B. HCl and then diluted with water either by the addition of water or by the condensation of steam used to heat the bath, so that the most concentrated tank of the pickling line, from which the steel exits, will contain about 10 to 15 percent of HCl. The other tanks of the line will contain varying amounts of acid, depending on the number of tanks, the rate of travel of the steel strip, bath temperature, and related factors. The actual concentration of acid is maintained by the operators according to plant conditions by addition of the concentrate.
The polyethylene glycol serves, we now believe, to increase the solubility in concentrated hydrochloric acid of the phosphate salt and thus permits the formulation of the concentrate that characterizes this invention and which in turn avoids the shipment of large quantities of water.
In the production of the concentrate it is preferred to use a polyethylene glycol such as one of about 6,000 average molecular weight, which is a waxy solid at room temperature. The monoethanolamine may be replaced by diethanolamine or triethanolamine, and mixtures of any two or all three of them may be used likewise. Instead of the phosphate specified for the bath it may be supplied to the concentrate as sodium chloride and orthophosphoric acid in amounts equivalent to the specified amount of sodium dihydrogen phosphate monohydrate.
Conventional pickling equipment is used in the practice of this invention. There is nothing critical in the temperature of the bath but generally it should range from about F. to not over about 210 F. The pickled strip is treated conventionally by subjecting it to a cold water spray followed by a hot water spray and then flash drying it at about 230 F.
In accordance with conventional pickling practice the steel moves countercurrently to the direction of fiow of the pickling liquor with makeup acid being supplied by concentrate added at the end of the tank from which the strip exits.
According to the provisions of the patent statutes, we have explained the principle of our invention and have described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
Weclairn:
1. In a method of pickling steel the steps of blending about 5 to percent of B. HCl with a pickling bath concentrate consisting essentially of, by weight, about to percent of 20 B. hydrochloric acid and about 10 to 15 percent additional water, about 1 to 3 percent of sodium dihydrogen phosphate monohydrate, about 0.5 to 1.5 percent of polyethylene glycol, and about 0.2 to 1.5 percent of at least one ethanolamine, diluting the blend with water to about 8 to 15 percent of HCl, and passing the steel through the resultant bath.
2. Method according to claim 1, said glycol being of about 6,000 molecular weight.
3. Method according to claim 1. said ethanolaminebe-= ing monoethanolamine.
4 4. concentrate for preparing a steel pickling bath consisting essentially of, by weight, about 80 to 85 percent of 20 B. hydrochloric acid, about 1 to 3 percent of sodium dihydrogen phosphate monohydrate, about 0.5 to
1.5 percent of poly -thyiene glycol, about 0.2 to 1.5 percent of an ethanolamine, and about 10 to 15 percent of added water.
5. Concentrate according to claim 4, said ethanolamine being monoethanolamine.
References Cited 20 REUBEN FRIEDMAN, Primary Examiner.
J. L. DE CESARE, Assistant Examiner
Claims (1)
1. IN A METHOD OF PICKLING STEEL THE STEPS OF BLENDING ABOUT 5 TO 15 PERCENT OF 20* BE. HCL WITH A PICKLING BATH CONCENTRATE CONSISTING ESSENTIALLY OF, OF WEIGHT, ABOUT 80 TO 85 PERCENT OF 20*BE. HYDROCHLORIC ACID AND ABOUT 10 TO 15 PERCENT ADDITIONAL WATER, ABOUT 1 TO 3 PERCENT OF SODIUM DIHYDROGEN PHOSPHATE MONOHYDRATE, ABOUT 0.5 TO 1.5 PERCENT OF POLYETHYLENE GLYCOL, AND ABOUT 0.2 TO 1.5 PERCENT OF AT LEAST ONE ETHANOLAMINE, DILUTING THE BLEND WITH WATER TO ABOUT 8 TO 15 PERCENT OF HCL, AND PASSING THE STEEL THROUGH THE RESULTANT BATH.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US415493A US3385734A (en) | 1964-12-02 | 1964-12-02 | Process and composition for pickling steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US415493A US3385734A (en) | 1964-12-02 | 1964-12-02 | Process and composition for pickling steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3385734A true US3385734A (en) | 1968-05-28 |
Family
ID=23645900
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US415493A Expired - Lifetime US3385734A (en) | 1964-12-02 | 1964-12-02 | Process and composition for pickling steel |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3385734A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4873014A (en) * | 1988-01-27 | 1989-10-10 | The Dow Chemical Company | Polyamine-polyglycol inhibitor for steel pickling |
| EP0357794A1 (en) * | 1988-03-10 | 1990-03-14 | Nkk Corporation | Process for pickling electrical steel sheet |
| US5851304A (en) * | 1996-02-27 | 1998-12-22 | Usinor Sacilor | Process for pickling a piece of steel and in particular a sheet strip of stainless steel |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1723923A (en) * | 1928-03-14 | 1929-08-06 | Carbide & Carbon Chem Corp | Inhibitor |
| US2438877A (en) * | 1945-09-06 | 1948-03-30 | American Chem Paint Co | Composition for and method of coating aluminum |
| US2916459A (en) * | 1954-12-13 | 1959-12-08 | Ajem Lab Inc | Metal cleaner |
| US3079345A (en) * | 1959-04-30 | 1963-02-26 | Dow Chemical Co | Propargyl compounds as corrosion inhibitors |
| US3211659A (en) * | 1961-10-02 | 1965-10-12 | Purex Corp Ltd | Process and compositions for cleaning shell eggs |
| US3239467A (en) * | 1962-02-15 | 1966-03-08 | Lord Corp | Metal cleaning and treating compositions |
-
1964
- 1964-12-02 US US415493A patent/US3385734A/en not_active Expired - Lifetime
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1723923A (en) * | 1928-03-14 | 1929-08-06 | Carbide & Carbon Chem Corp | Inhibitor |
| US2438877A (en) * | 1945-09-06 | 1948-03-30 | American Chem Paint Co | Composition for and method of coating aluminum |
| US2916459A (en) * | 1954-12-13 | 1959-12-08 | Ajem Lab Inc | Metal cleaner |
| US3079345A (en) * | 1959-04-30 | 1963-02-26 | Dow Chemical Co | Propargyl compounds as corrosion inhibitors |
| US3211659A (en) * | 1961-10-02 | 1965-10-12 | Purex Corp Ltd | Process and compositions for cleaning shell eggs |
| US3239467A (en) * | 1962-02-15 | 1966-03-08 | Lord Corp | Metal cleaning and treating compositions |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4873014A (en) * | 1988-01-27 | 1989-10-10 | The Dow Chemical Company | Polyamine-polyglycol inhibitor for steel pickling |
| EP0357794A1 (en) * | 1988-03-10 | 1990-03-14 | Nkk Corporation | Process for pickling electrical steel sheet |
| EP0357794A4 (en) * | 1988-03-10 | 1990-09-05 | Nkk Corporation | Process for pickling electrical steel sheet |
| US5851304A (en) * | 1996-02-27 | 1998-12-22 | Usinor Sacilor | Process for pickling a piece of steel and in particular a sheet strip of stainless steel |
| US5992196A (en) * | 1996-02-27 | 1999-11-30 | Usinor | Process for pickling a piece of steel and in particular a sheet strip of stainless steel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3072502A (en) | Process for removing copper-containing iron oxide scale from metal surfaces | |
| AU2015249410B2 (en) | Method and formulations for removing rust and scale from steel and for regenerating pickling liquor in hot-dip galvanization process | |
| DE1446383A1 (en) | Scale removal | |
| DE1095623B (en) | An acid bath containing an inhibitor for cleaning and pickling metal surfaces | |
| US3385734A (en) | Process and composition for pickling steel | |
| DE2328763C2 (en) | Aqueous alkaline borate cleaning agent and process for its preparation | |
| DE3222532C2 (en) | ||
| CH497547A (en) | Process for cleaning and pickling ferrous metal surfaces, in particular the surfaces of the pipelines of steam generators | |
| US3349037A (en) | Additive for stainless steel pickling baths | |
| US2209291A (en) | Rust removing composition | |
| Hudson | Pickling and descaling | |
| US4873014A (en) | Polyamine-polyglycol inhibitor for steel pickling | |
| STREICHER | Synergistic inhibition of ferric ion corrosion during chemical cleaning of metal surfaces | |
| US2877146A (en) | Metallurgical pickling | |
| DE1949339A1 (en) | Corrosion protection | |
| DE618614C (en) | Process for bright pickling of metals | |
| US3440095A (en) | Process for treating metal | |
| NO154275B (en) | EDGE DEVICE FOR L! PEBANE INSIDE IN A SPORTING EQUIPMENT. | |
| US2411791A (en) | Pickling of ferrous metals | |
| US3362912A (en) | Corrosion restraining composition | |
| DE2315437C2 (en) | Process for the pre-treatment of steel strip surfaces before annealing | |
| US1756311A (en) | Method of cleaning metals | |
| DE628795C (en) | Method of removing beer stone | |
| AT121995B (en) | Process for removing a lead layer covering metal bodies. | |
| DE648899C (en) | Process for the production of a pigment suitable for anti-rust oil paints |