EP0184115B1 - Oberflächenbehandeltes Stahlband mit verbesserter Schweissbarkeit und Verfahren zu seiner Herstellung - Google Patents

Oberflächenbehandeltes Stahlband mit verbesserter Schweissbarkeit und Verfahren zu seiner Herstellung Download PDF

Info

Publication number
EP0184115B1
EP0184115B1 EP85114989A EP85114989A EP0184115B1 EP 0184115 B1 EP0184115 B1 EP 0184115B1 EP 85114989 A EP85114989 A EP 85114989A EP 85114989 A EP85114989 A EP 85114989A EP 0184115 B1 EP0184115 B1 EP 0184115B1
Authority
EP
European Patent Office
Prior art keywords
tin
chromium
strip
metallic
deposited
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
Application number
EP85114989A
Other languages
English (en)
French (fr)
Other versions
EP0184115A1 (de
Inventor
Hisatada Nakakouji
Kazuo Mochizuki
Toshio Ichida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
Kawasaki Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Kawasaki Steel Corp filed Critical Kawasaki Steel Corp
Publication of EP0184115A1 publication Critical patent/EP0184115A1/de
Application granted granted Critical
Publication of EP0184115B1 publication Critical patent/EP0184115B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/38—Chromatising
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/30—Electroplating: Baths therefor from solutions of tin
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/10—Electroplating with more than one layer of the same or of different metals
    • C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium

Definitions

  • This invention relates to surface-treated steel strips or sheets having improved weldability, particularly improved seam weldability and sufficient corrosion resistance for use as can forming stock, and a process for making such surface-treated steel strips.
  • tin-coated steel strips generally called tin plates.
  • conventional soldering techniques were previously used. Because of the toxicity of lead contained in conventional solder, pure tin solder has recently become prevalent. The pure tin solder, however, has a technical problem in making a joint because of inferior wetability during the soldering process and is so expensive as to create the economic problem of increased manufacture cost.
  • tin-free steel of chromium type is another typical example of conventional cam-forming steel (cf e.g. EP-A-121817).
  • the tin-free steel is prepared by carrying out an electrolytic chromate treatment on steel to form metallic chromium and hydrated chromium oxide layers on the surface. Since the relatively thick hydrated chromium oxide layer at the top has a relatively high electric resistance, the chromated steel is ineffectively welded to form a weld of insufficient strength and thus unsuitable as welded can-forming steel despite its economic advantage.
  • nickel-plated steel typically "Nickel-Lite” announced by National Steel Corporation of the U.S. which is prepared by plating a steel strip with nickel to a thickness of about 0.5 g/m 2 followed by a conventional chromate treatment. Inferior adhesion of lacquer and inferior weldability in high speed welding at 30 m/min. or higher have limited the spread of this nickel-plated steel.
  • Tit Alloy announced by Jones & Laughlin Steel Corporation of the U.S. This is prepared by thinly coating a steel strip with tin to a thickness of about 0.6 g/m 2 and effecting tin reflow or flow melting followed by a conventional chromate treatment. Unfortunately, rust resistance, lacquer adhesion and weldability are insufficient.
  • can-forming steel sheets intended for electric resistance welding are required to exhibit improved weldability and corrosion resistance after lacquering. These requirements will be explained in detail.
  • the improved corrosion resistance of the underlying steel itself must prevent corrosion from proceeding.
  • an object of the present invention to provide a novel and improved surface-treated steel strip which can be seam welded into cans without the above-mentioned drawbacks and has improved weldability, corrosion resistance after lacquering, and lacquer adhesion.
  • Another object of the present invention is to provide a process for making such an improved can-forming stock in a simple and inexpensive manner.
  • a surface-treated steel strip having improved weldability comprising
  • a process for preparing a surface-treated steel strip having improved weldability is provided.
  • the surface-treated steel strip particularly suitable as can-forming stock is prepared by
  • the acidic tin-plating bath contains hydrochloric acid and/or sulfuric acid and an insoluble anode is used to carry out the tin electrodeposition.
  • metallic tin which has a relatively low melting point is readily melted during welding and spread under the welding pressure to increase the contact area between steel pieces and to facilitate mutual fusion of the steel pieces. "Splashes" due to local concentration of welding current are unlikely to occur. Formation of a strong welding joint provides a wide range of available welding current. Conventional #25 tin plate has a wide available welding current range because it contains about 2.2 g/m 2 of metallic tin.
  • an iron-tin alloy can be substantially controlled by interposing metallic chromium between tin and substrate iron.
  • the content of tin in an alloy formed by a baking treatment at 210°C for 20 minutes is plotted in Figure 1 as a function of the amount of the underlying metallic chromium.
  • the intervening metallic chromium is significantly effective in preventing an iron-tin alloy from forming during the baking.
  • the metallic chromium which itself is a highly corrosion resistant metal has doulble functions of preventing formation of an iron-tin alloy and improving corrosion resistance at the same time.
  • lacquer baking forms tin oxide at the surface, resulting in insufficient lacquer adherence and hence, poor corrosion resistance after lacquering.
  • sulfide stain occurs, that is, tin sulfide having a black color forms to blacken the can inner surface.
  • Prior art tinplate is cathodically treated in an electrolytic solution of sodium dichromate to form a coating of hydrated chromium oxides to mitigate the sulfide stain. The hydrated chromium oxide coating, however, does not perform well.
  • the surface-treated steel strip of the present invention should have as an uppermost layer a chromate coating layer consisting essentially of 3 to 15 mg/m 2 of metallic chromium and 3 to 15 mg/m 2 of hydrated chromium oxide calculated as elemental chromium.
  • the steel strip of the present invention Since the steel strip of the present invention is intended for use in forming food cans, it is always coated with lacquer on one surface which becomes the inner surface of a can made therefrom. Most important among the requisite can properties are corrosion resistance after lacquering and sulfide staining resistance. Metallic chromium on the tin layer is essential to provide such resistances. Metallic chromium must be deposited in amounts of at least 3 mg/m 2. An excessive amount of metallic chromium can interfere with weldability as it is oxidized to form chromium oxide at elevated temperatures during welding. The upper limit of 15 mg/m 2 is thus imposed to the metallic chromium amount.
  • the hydrated chromium oxide is effective in improving lacquer adherence and corrosion resistance. Since hydrated chromium oxide itself is a high electric resistance material, it can interfere with weldability when present in excessive amounts. For this reason, the hydrated chromium oxide is limited to the range from 3 to 15 mg/m 2 calculated as elemental chromium.
  • a starting steel strip which may be one commonly used as the starting steel strip for tinplate or tin-free steel (TFS) strips is cleaned by any conventional techniques, for example, electrolytic degreasing and pickling.
  • the cleaned surface of steel strip is subjected to electrodeposition of metallic chromium to a coating weight of 50 to 150 mg/m 2 .
  • the underlying metallic chromium is plated for the purposes of preventing formation of an iron-tin alloy during lacquer baking and improving corrosion resistance.
  • Metallic chromium is effective in preventing iron-tin alloy even in as small amounts as 5 mg/m 2.
  • metallic chromium is desirably deposited in a coating weight of at least 50 mg/m 2 in order to effectively prevent alloying of expensive tin. The larger the amount of metallic chromium, the greater are the iron-tin alloying prevention and the corrosion resistance.
  • Metallic chromium amounts in excess of 150 mg/m 2 are uneconomic because the iron-tin alloying prevention and the corrosion resistance improvement reach plateau at such a level. Excessive metallic chromium is also undesirable because such a thick chromium plating is liable to cracks due to electrodeposition stress.
  • Metallic chromium may be deposited on the steel strip by any well-known methods, for example, by a well-known electrodeposition method as by carrying out cathodic electrolysis in an aqueous solution containing a major proportion of chromic acid anhydride and an additive amount of sulfate (SO 4 -- ) and fluoride (F-). Upon completion of chromium electrodeposition, the steel strip is rinsed with water.
  • a well-known electrodeposition method as by carrying out cathodic electrolysis in an aqueous solution containing a major proportion of chromic acid anhydride and an additive amount of sulfate (SO 4 -- ) and fluoride (F-).
  • SO 4 -- sulfate
  • F- fluoride
  • tin plating is applied onto the metallic chromium layer on the steel strip.
  • a conventional tin electrodeposition process fails to achieve satisfactory tin plating because hydrated chromium oxide is present on the metallic chromium surface.
  • the ordinary industrial chromium electrodeposition is to electrochemically reduce hexavelent chromium ion (Cr") to metallic chromium. Since Crs+ ion is reduced to metallic Cr through the hydrated oxide of trivalent chromium as is well known in the art, hydrated chromium oxide is always present on the plating surface. This hydrated chromium oxide interferes with tin electrodeposition. When tin electrodeposition is effected in the presence of hydrated chromium oxide on the metallic chromium surface, there is obtained a deposit having poor bond strength.
  • the hydrated chromium oxide In order to effectively electrodeposit tin, the hydrated chromium oxide must be previously removed from the electrodeposited chromium surface. Removal of hydrated chromium oxide may be effected by a variety of well-known methods, for example, by dissolving away in a hot aqueous alkaline solution or by dissolving away in an aqueous solution such as sodium hydroxide solution, phosphate buffer solution, and borate buffer solution through anodic electrolysis.
  • tin plating pretreatment is a method for depositing various metals onto the surface of chromium and chromium alloys as disclosed in Japanese Patent Publication No. 33-1455.
  • the surface activating treatment with caustic alkali as disclosed therein fails to provide a tin deposit having a practically acceptable bond strength.
  • a further method is disclosed in Japanese Patent Application Kokai No. 60-190597 entitled "Surface-treated steel strip for use in welded cans and method for making". There are disclosed a pretreatment by cathodic electrolysis in an acid solution at pH 0.5 to 2 and tin electrodeposition from a tin plating bath having a low tin ion concentration and pH 0.5 to 3. Removal of hydrated chromium oxide is still insufficient to ensure satisfactory tin deposition.
  • the process in such a specific bath according to the present invention carries out tin deposition and generates a great volume of active H 2 gas at the same time. Evolution of a great volume of active hydrogen gas on the deposited chromium surface in a strongly acidic solution can completely remove the hydrated chromium oxide which could not otherwise completely be removed from the deposited chromium surface. Tin deposition proceeds concurrently. As a result, there is deposited a tin layer having a high bond strength to the chromium layer.
  • the tin electrodeposition may be carried out at a bath temperature of 25 to 65°C and a cathodic current density of 15 to 50 amperes per square decimeter (A/dm 2 ).
  • the tin plating bath used herein contains tin ion at a concentration of 1.5 to 10 grams per liter. Tin ion concentrations of less than 1.5 g/I do not allow tin to deposit on the chromium layer whereas high concentrations in excess of 10 g/I result in a coarse deposit of powder or dendrite structure having too poor appearance to meet practical application.
  • the tin plating bath should have a hydrogen ion concentration in excess of 0.32 mols per liter, that is, lower than 0.5 in pH. Baths having a hydrogen ion concentration of 0.32 mol/I or lower, that is, at least pH 0.5 are insufficient to impart a strongly acidic environment necessary to remove the hydrated chromium oxide and to generate a great volume of active hydrogen gas, so that the hydrated chromium oxide is not completely removed and a satisfactory tin deposit is not obtained. It is preferable to add hydrochloric acid and/or sulfuric acid to the acidic bath to provide a pH value of lower than 0.5.
  • the tin deposition efficiency at the cathode is lower than the tin dissolving efficiency at the anode (tin anode) because of the high acidity. If tin electrodeposition is continued under such conditions for an extended period of time, the tin ion concentration of the bath is gradually increased to eventually exceed the critical level of 10 g/I, resulting in a coarse deposit.
  • the source for supplying tin ion to the tin plating bath according to the present invention may be any tin compounds such as tin sulfate, tin chloride, tin borofluoride, tin pyrophosphate, tin fluoride, and similar tin compounds.
  • the acid added to the tin plating bath may be any one or mixtures of inorganic acids such as sulfuric acid, hydrochloric acid, hydrofluoric acid, borofluoric acid, etc. and organic acids such as phonolsulfonic acid, cresolsulfonic acid, etc.
  • tin sulfate As the tin ion source and sulfuric acid as the acid
  • an insoluble anode formed of Pb, Pb alloys, Pt, etc. may conveniently be used to eliminate the above-mentioned problem of rising tin ion concentration.
  • Jhe tin ion may be made up simply by dissolving tin sulfate or tin oxide or finely divided metallic tin into the plating solution.
  • the amount of tin deposited may be determined in conjunction with the underlying metallic chromium amount such that at least 50 mg/m 2 , preferably at least 100 mg/m 2 of metallic tin is left at the end of lacquer baking. Excessive amounts of tin deposited have no detrimental effect, but the tin coating weight may desirably be up to 400 mg/m 2 for economic reasons. The preferred amount of tin deposited thus ranges from 50 to 400 mg/m 2 .
  • the tin plating bath used in the practice of the present process may further contain a surface-active agent having an oxyethylene chain -[CH2CH20-]n-, for example, ethylene glycol, polyethylene glycol, a polyethylene glycol alkyl ether such as ethylene glycol monomethyl ether, etc., an aromatic ethylene oxide such as ethoxylated a-naphthol, etc., and a polyethylene glycol-fatty acid ester in amounts of 0.1 to 10 grams per liter.
  • a surface-active agent having an oxyethylene chain -[CH2CH20-]n-, for example, ethylene glycol, polyethylene glycol, a polyethylene glycol alkyl ether such as ethylene glycol monomethyl ether, etc., an aromatic ethylene oxide such as ethoxylated a-naphthol, etc., and a polyethylene glycol-fatty acid ester in amounts of 0.1 to 10 grams per liter.
  • a surface-active agent results in
  • Concentrations of oxyethylene chain-bearing surface-active agent of lower than 0.1 g/I are too low to improve the appearance and tone whereas the effect is saturated beyond the concentration of 10 g/I.
  • the use of such an expensive surface-active agent in an unnecessarily excessive amount is, of course, not economical. Since the oxyethylene chain-bearing surface-active agent is expensive, it is desired to add it only when a particularly good appearance and tone is required.
  • the tin deposited strip is rinsed with water to be ready for subsequent treatment.
  • a chromate coating layer consisting essentially of metallic chromium and hydrated chromium oxide is further deposited on the tin layer for the purpose of improving lacquer adherence, corrosion resistance after lacquering, and sulfide staining resistance.
  • the amount of metallic chromium should be at least 3 mg/m 2 to achieve significant improvements in lacquer adherence, corrosion resistance after lacquering, and sulfide staining resistance.
  • the larger the amount of metallic chromium the greater are improved the lacquer adherence, corrosion resistance after lacquering, and sulfide staining resistance. Too large amounts of metallic chromium in excess of 15 mg/m 2 tend to be oxidized at elevated temperatures during subsequent welding into chromium oxide to detract from weldability, and are thus undesirable.
  • the amount of hydrated chromium oxide should be at least 3 mg/m 2 calculated as elemental chromium. Since the hydrated chromium oxide itself is a high electric resistance matrial, it impedes weldability when present in large amounts. The amount of hydrated chromium oxide should preferably be limited up to 15 mg/m 2 calculated as elemental Cr.
  • the metallic chromium and hydrated chromium oxide may be formed by carrying out cathodic electrolysis in a bath containing at least 50 grams per liter of Cr0 3 and an effective amount of one member selected from sulfuric acid, sulfate salts, fluorides, and mixtures thereof at a current density of at least 10 A/dm 2 .
  • the metallic Cr and hydrated Cr oxide may be formed any desired combination by properly selecting cathodic electrolysis conditions including current density, bath temperature, bath concentration, and the like.
  • Chromate baths containing CrO 3 in concentrations of higher than 50 g/I undesirably attack and etch the tin layer whereas low current densities of lower than 10 A/dm 2 are difficult to produce metallic chromium.
  • a steel stock strip generally intended for conventional tinplate or TFS was electrolytically degreased, pickled, and then subjected to chromium electrodeposition in a bath containing 200 g/I of Cr0 3 and 2 g/I of H 2 SO 4 at a temperature of 50°C and a current density of 40 A/dm 2 .
  • the Cr deposited strip was rinsed with water and then subjected to tin electrodeposition in a tin plating bath containing 4 g/I of SnCl 2 2H 2 0 and adjusted to pH 0.3 with HCI at a temperature of 50°C and a current density of 20 A/dm 2.
  • the Sn deposited strip was rinsed with water and then subjected to chromate treatment in a bath containing 20 g/I of CrO 3 and 0.2 g/I of H 2 SO 4 at a temperature of 50°C and a current density of 15 A/dm 2 , thereby forming metallic chromium and hydrated chromium oxide as a topcoat.
  • a steel stock strip generally intended for conventional tinplate or TFS was electrolytically degreased, pickled, and then subjected to chromium electrodeposition in a bath containing 180 g/I of Cr0 3 , 6 g/I of Na 2 SiF 6 , and 0.75 g/I of H 2 S0 4 at a temperature of 50°C and a current density of 50 A/dm l .
  • the Cr deposited strip was rinsed with water and then subjected to tin electrodeposition in a tin plating bath containing 6 g/I of SnS0 4 and adjusted to pH 0.48 with H 2 S0 4 at a temperature of 40°C and a current density of 30 A/dm 2 .
  • the Sn deposited strip was rinsed with water and then subjected to chromate treatment in a bath containing 15 g/1 of Cr0 3 and 1.5 g/I of NH 4 F at a temperature of 45°C and a current density of 15 A/dm 2 , thereby forming metallic chromium and hydrated chromium oxide as a topcoat.
  • a steel stock strip generally intended for conventional tinplate or TFS was electrolytically degreased, pickled, and then subjected to chromium electrodeposition in a bath containing 150 g/I of Cr0 3 and 7.5 g/I of NaF at a temperature of 50°C and a current density of 35 A/dm 2 .
  • the Cr deposited strip was rinsed with water and then subjected to tin electrodeposition in a tin plating bath containing 8 g/I of SnS0 4 and adjusted to pH 0.2 with H 2 SO 4 at a temperature of 45°C and a current density of 25 A/dm 2 using an insoluble anode of Pb-Sn alloy.
  • the Sn deposited strip was rinsed with water and then subjected to chromate treatment in a bath containing 15 g/I of Cr0 3 and 0.12 g/I of H 2 S0 4 at a temperature of 50°C and a current density of 20 A/dm 2 , thereby forming metallic chromium and hydrated chromium oxide as a topcoat.
  • a steel stock strip generally intended for conventional tinplate or TFS was electrolytically degreased, pickled, and then subjected to chromium electrodeposition in a bath containing 250 g/I of CrO 3 , 5 g/I of Na 2 SiF 6 , and 1.5 g/I of H 2 SO 4 at a temperature of 55°C and a current density of 50 A/dm 2 .
  • the Cr deposited strip was rinsed with water and then subjected to tin electrodeposition in a tin plating bath containing 4 g/I of SnS0 4 and adjusted to pH 0.40 with H 2 SO 4 at a temperature of 30°C and a current density of 20 A/dm 2 using an insoluble anode of platinum.
  • the Sn deposited strip was rinsed with water and then subjected to chromate treatment in a bath containing 30 g/I of Cr0 3 and 0.27 g/I of H2S04 at a temperature of 40°C and a current density of 25 A/dm 2 , thereby forming metallic chromium and hydrated chromium oxide as a topcoat.
  • a steel stock strip generally intended for conventional tinplate or TFS was electrolytically degreased, pickled, and then subjected to chromium electrodeposition in a bath containing 200 g/I of Cr0 3 , 5.5 g/I of Na 2 SiF 6 , and 1.0 g/I of H 2 S0 4 at a temperature of 40°C and a current density of 55 A/dm 2 .
  • the Cr deposited strip was rinsed with water and then subjected to tin electrodeposition in a tin plating bath containing 5 g/I of SnS0 4 and adjusted to pH 0.45 with H 2 S0 4 at a temperature of 35°C and a current density of 40 A/dm2.
  • the Sn deposited strip was rinsed with water and then subjected to chromate treatment in a bath containing 20 g/I of CrO 3 and 3 g/I of NH 4 F at a temperature of 45°C and a current density of 30 A/dm2, thereby forming metallic chronium and hydrated chromium oxide as a topcoat.
  • a steel stock strip generally intended for conventional tinplate or TFS was electrolytically degreased, pickled, and then subjected to chromium electrodeposition in a bath containing 180 g/I of Cr0 3 , 6 g/I of Na 2 SiF 6 , and 0.75 g/I of H 2 SO 4 at a temperature of 55°C and a current density of 50 A/dm 2 .
  • the Cr deposited strip was rinsed with water and then subjected to tin electrodeposition in a tin plating bath containing 6 g/I of SnS0 4 and adjusted to pH 0.46 with H 2 S0 4 at a temperature of 35°C and a current density of 35 A/dm 2 .
  • the Sn deposited strip was rinsed with water and then subjected to chromate treatment in a bath containing 24 g/I of Cr0 3 and 2 g/I of NaF at a temperature of 40°C and a current density of 35 A/dm 2 , thereby forming metallic chromium and hydrated chromium oxide as a topcoat.
  • Example 2 Cr electrodeposition and Sn electrodeposition were carried out under the same conditions as in Example 1.
  • the Sn deposited strip was rinsed with water and then only hydrated chromium oxide was formed thereon in a bath containing 30 g/I of Na 2 Cr 2 O 7 . 2H 2 0 at a temperature of 40°C and a current density of 5 A/dm 2 .
  • the thus treated steel strip samples were evaluated for various properties by the following procedures.
  • Sample pieces overlapped a distance of 0.4 mm were seam welded by means of an electric resistance seam welding machine using a copper wire as the electrode at a welding speed of 40 m/min. and a welding force or can body joining force of 40 kg - f to determine the available welding current range (ACR) within which a sound weld having a sufficient strength was accomplished without generating a splash.
  • ACR available welding current range
  • the sample was subjected to a heat treatment at 210°C for 20 minutes which was the. expected lacquer baking.
  • Two sample pieces (5 mm x 100 mm) were coated with an epoxy-phenol lacquer to a coating weight of 50 mg/dm 2 , overlapped a distance of 90 mm from the edge, and heat bonded to each other with a nylon adhesive.
  • the unjoined portions were outwardly bent over an angle of 90° to form a T shape and oppositely pulled at a pulling speed of 200 mm/min. to determine tensile strength.
  • the tensile strength at which the pieces were peeled off is evaluated as lacquer adherence and called T-peel strength as expressed in kg/5 mm.
  • a sample piece (40 mmx80 mm) was coated with an epoxy-phenol lacquer to a coating weight of 50 mg/dm 2 , inserted into boiled tomato juice in a glass container such that the lower half of the sample was immersed, and held in the closed container at 55°C for 18 days. The sample was taken out of the container and observed for blister occurrence.
  • the criterion of evaluation is shown below.
  • a sample piece was coated with an epoxy-phenol lacquer to a coating weight of 50 mg/dm 2 , drawn by a distance of 5 mm by means of an Erichsen machine, immersed in a test solution containing 1% Na 2 S and adjusted to pH 7 with lactic acid (pH 3.5), and heat treated at 110°C for 60 minutes.
  • the processed and unprocessed (flat) portions of the sample were observed for sulfide staining. The criterion of evaluation is shown below.
  • Figure 1 graphically illustrates the tin content in an alloy resulting from a baking treatment (210°C, 20 min.) as a function of the amount of underlying metallic chromium.
  • Figure 2 graphically illustrates the corrosion resistance after lacquering as a function of the amount of metallic chromium on the tin layer and the amount of hydrated chromium oxide calculated as elemental chromium.
  • the surface-treated steel strip of the present invention which has a surface coating consisting essentially of a Cr layer, Sn layer, metallic Cr layei, and hydrated Cr layer in specific coating weights displays improved weldability, lacquer adherence, corrosion resistance after lacquering, and sulfide staining resistance.
  • the present process enables surface treatments of a steel strip such that the Cr layer, Sn layer, metallic Cr layer, and hydrated Cr oxide layer are formed to the specific coating weights, and thus ensures the efficient production of surface-treated steel strips meeting the requirements for can-forming stock material.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)

Claims (3)

1. Oberflächenbehandeltes Stahlband verbesserter Schweißbarkeit, umfassend
ein Stahlband,
eine auf dem Stahlband bis zu einem Beschichtungsgewicht von 50-150 mg/m2 abgelagerte metallische Chromschicht,
eine auf der Chromschicht bis zu einem Beschichtungsgewicht von 50-400 mg/m2 abgelagerte metallische Zinnschicht und
einen auf der Zinnschicht abgelagerten und im wesentlichen aus 3-15 mg/m2 metallischen Chroms und 3-15 mg/m2 hydratisierten Chromoxids (berechnet als elementares Chrom) bestehenden schichtartigen Chromatüberzug.
2. Verfahren zur Herstellung eines oberflächen behandelten Stahlbandes verbesserter Schweißbarkeit, umfassend folgende Stufen:
Säuberung mindestens einer Oberfläche eines Stahlbandes, galvanische Verchromung der gesäuberten Bandoberfläche bis zu einem Beschichtungsgewicht von 50-150 mg/m2, Spülung des verchromten Bandes mit Wasser,
elektrolytische Verzinnung des Bandes in einem sauren Bad mit 1,5-10 g/I Sn-lonen bei einem pH-Wert von weniger als 0,5 bis zu einem Beschichtungsgewicht von 50-400 mg/m2,
Spülung des verzinnten Bandes mit Wasser und
Chromatbehandlung des Bandes in einem Chromatbad mit bis zu 50 g/I Cr03 und mindestens einen Bestandteil aus der Gruppe Schwefelsäure, Sulfate und Fluoride bei einer Stromdichte von mindestens 10 Aldm2 zur Bildung eines schichtartigen Chromatüberzugs, der im wesentlichen aus 3-15 mg/m2 metallischen Chroms und 3-15 mg/m2 hydratisierten Chromoxids (berechnet als elementares Chrom) besteht.
3. Verfahren zur Herstellung eines oberflächenbehandelten Stahlbandes verbesserter Schweißbarkeit nach Anspruch 2, dadurch gekennzeichnet, daß das saure Verzinnungsbad Sn-lonen und Schwefelsäure enthält und zur Durchführung der galvanischen Verzinnung eine unlösliche Anode verwendet wird.
EP85114989A 1984-11-29 1985-11-26 Oberflächenbehandeltes Stahlband mit verbesserter Schweissbarkeit und Verfahren zu seiner Herstellung Expired EP0184115B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP59252355A JPS61130500A (ja) 1984-11-29 1984-11-29 Ｓｎ／Ｃｒ２層めつき鋼板の製造方法
JP252355/84 1984-11-29

Publications (2)

Publication Number Publication Date
EP0184115A1 EP0184115A1 (de) 1986-06-11
EP0184115B1 true EP0184115B1 (de) 1989-02-22

Family

ID=17236135

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85114989A Expired EP0184115B1 (de) 1984-11-29 1985-11-26 Oberflächenbehandeltes Stahlband mit verbesserter Schweissbarkeit und Verfahren zu seiner Herstellung

Country Status (8)

Country Link
EP (1) EP0184115B1 (de)
JP (1) JPS61130500A (de)
KR (1) KR900001829B1 (de)
CN (1) CN1006694B (de)
AU (1) AU559801B2 (de)
CA (1) CA1273600A (de)
DE (1) DE3568356D1 (de)
ZA (1) ZA859071B (de)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4563399A (en) * 1984-09-14 1986-01-07 Michael Ladney Chromium plating process and article produced
JPS61130500A (ja) * 1984-11-29 1986-06-18 Kawasaki Steel Corp Ｓｎ／Ｃｒ２層めつき鋼板の製造方法
JPS6376896A (ja) * 1986-09-18 1988-04-07 Nippon Steel Corp シ−ム溶接性、耐食性に優れた表面処理鋼板の製造方法
JPH01191772A (ja) * 1988-01-26 1989-08-01 Toyo Kohan Co Ltd 加工耐食性の優れた製缶用めっき素地鋼板の製造方法
JP2707884B2 (ja) * 1991-09-06 1998-02-04 日本鋼管株式会社 複層電解クロメート処理鋼板の製造方法
KR20020050383A (ko) * 2000-12-21 2002-06-27 이구택 용접성이 우수한 용기용 표면처리강판의 제조방법
CN1313470C (zh) * 2004-02-11 2007-05-02 上海新先锋药业有限公司 N－甲基苯并噻唑力复霉素的制备方法
CN101015971B (zh) * 2007-02-05 2011-05-11 蒋彩峰 钢板式新型装饰板及制作方法
CN102191513B (zh) * 2011-04-28 2012-08-22 北京化工大学 一种不溶性钛基催化电极的制备方法
ES2583372T3 (es) * 2012-03-30 2016-09-20 Tata Steel Ijmuiden Bv Sustrato recubierto para aplicaciones de empaquetado y un método para producir dicho sustrato recubierto
CN104936738B (zh) * 2013-01-29 2018-12-18 大日制罐株式会社 焊接罐体、焊接罐、焊接罐体的制造方法及焊接罐的制造方法
CN103921499B (zh) * 2014-04-22 2017-02-15 刘建忠 具有优异钎焊性能的金属材料
CN110885999A (zh) * 2018-09-10 2020-03-17 上海梅山钢铁股份有限公司 一种冷轧电镀锡钢板的铬酸钝化方法
CN113529141B (zh) * 2021-06-17 2022-11-18 首钢集团有限公司 一种锡铬复合镀层钢板及其制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2465011A1 (fr) * 1979-09-06 1981-03-20 Carnaud Sa Materiau constitue d'une tole d'acier protegee, son procede de fabrication, et ses applications, ntamment aux boites de conserve
JPS59170298A (ja) * 1983-03-15 1984-09-26 Kawasaki Steel Corp 塗料密着性にすぐれたテインフリ−鋼板の製造方法
JPS60190597A (ja) * 1984-03-09 1985-09-28 Toyo Kohan Co Ltd 溶接缶用表面処理鋼板及びその製造方法
JPS61130500A (ja) * 1984-11-29 1986-06-18 Kawasaki Steel Corp Ｓｎ／Ｃｒ２層めつき鋼板の製造方法

Also Published As

Publication number Publication date
CA1273600A (en) 1990-09-04
DE3568356D1 (en) 1989-03-30
EP0184115A1 (de) 1986-06-11
AU5036685A (en) 1986-06-05
KR860004165A (ko) 1986-06-18
JPH052744B2 (de) 1993-01-13
CN85109305A (zh) 1986-08-06
JPS61130500A (ja) 1986-06-18
ZA859071B (en) 1986-07-30
KR900001829B1 (ko) 1990-03-24
CN1006694B (zh) 1990-02-07
AU559801B2 (en) 1987-03-19

Similar Documents

Publication Publication Date Title
US4388158A (en) Acidic tinplating process and process for producing an iron-tin alloy on the surface of a steel sheet
EP0184115B1 (de) Oberflächenbehandeltes Stahlband mit verbesserter Schweissbarkeit und Verfahren zu seiner Herstellung
EP0163048A2 (de) Stahlbänder die einer Oberflächenbehandlung unterworfen sind und für das Nahtschweissen geeignet sind
EP0131274B1 (de) Verfahren zur Herstellung von Stahlbändern, die einer Oberflächenbehandlung unterworfen sind und für elektrisches Widerstandsschweissen geeignet sind
JPH0216397B2 (de)
EP0194654B1 (de) Zinnfreie Stahlbänder, die zur Produktion geschweisster Dosen verwendet werden und Verfahren zu ihrer Herstellung
EP0063933B1 (de) Stahlblech mit unterschiedlichen Mehrschichtüberzügen, geeignet für Konservendosen
US4832800A (en) Process for preparing surface-treated steel strips adapted for electric resistance welding
US4508601A (en) Process for producing a thin tin and zinc plated steel sheet
JPH0214438B2 (de)
JPS6144158B2 (de)
KR910005239B1 (ko) 전해 크롬산염 용액처리 강판의 제조방법
JPH0368949B2 (de)
JPH0826477B2 (ja) 塗料密着性に優れたＳｎ系多層めっき鋼板の製造法
KR890001108B1 (ko) 전기저항 용접에 적절한 표면처리된 강 스트립 제조방법
JPS6240396A (ja) 溶接性、耐食性に優れた缶用表面処理鋼板
JP2593194B2 (ja) 塗装後加工部耐食性に優れた缶用表面処理鋼板の製造方法
JPS582597B2 (ja) すずめつき鋼板の製造方法
JPS60190597A (ja) 溶接缶用表面処理鋼板及びその製造方法
JPS6393894A (ja) 外面塗料密着性に優れた缶用鋼板
JPS6396294A (ja) 溶接性、耐食性に優れた缶用鋼板の製造方法
JPH01184297A (ja) 部分錫めっき鋼板のクロムめっき方法
JPS61250177A (ja) 製缶用表面処理鋼板
JPH10219477A (ja) 高温短時間焼き付け後の高速溶接性に優れた溶接缶用表面処理鋼板
JPS63105991A (ja) 耐食性、溶接性及び塗装性能に優れた高性能容器用表面処理鋼板の製造法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19851223

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE FR GB IT NL

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: KAWASAKI STEEL CORPORATION

17Q First examination report despatched

Effective date: 19880108

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE FR GB IT NL

ITF It: translation for a ep patent filed
REF Corresponds to:

Ref document number: 3568356

Country of ref document: DE

Date of ref document: 19890330

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19961128

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19970116

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19971112

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19971117

Year of fee payment: 13

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971130

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19971205

Year of fee payment: 13

BERE Be: lapsed

Owner name: KAWASAKI STEEL CORP.

Effective date: 19971130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980601

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19980601

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981126

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19981126

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990730

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990901