US3689941A - Method of fabricating and soldering stainless steel parts - Google Patents

Method of fabricating and soldering stainless steel parts Download PDF

Info

Publication number
US3689941A
US3689941A US49154A US3689941DA US3689941A US 3689941 A US3689941 A US 3689941A US 49154 A US49154 A US 49154A US 3689941D A US3689941D A US 3689941DA US 3689941 A US3689941 A US 3689941A
Authority
US
United States
Prior art keywords
sheets
lead
stainless steel
molten
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
Application number
US49154A
Inventor
Andre Chartet
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.)
Chausson Usines SA
Original Assignee
Chausson Usines SA
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 Chausson Usines SA filed Critical Chausson Usines SA
Application granted granted Critical
Publication of US3689941A publication Critical patent/US3689941A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
    • F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
    • F28F21/081—Heat exchange elements made from metals or metal alloys
    • F28F21/082—Heat exchange elements made from metals or metal alloys from steel or ferrous alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/02—Making other particular articles heat exchangers or parts thereof, e.g. radiators, condensers fins, headers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B23K1/0008—Soldering, e.g. brazing, or unsoldering specially adapted for particular articles or work
    • B23K1/0012—Brazing heat exchangers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/001—Interlayers, transition pieces for metallurgical bonding of workpieces
    • B23K35/004—Interlayers, transition pieces for metallurgical bonding of workpieces at least one of the workpieces being of a metal of the iron group
    • 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
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/10—Lead or alloys based thereon
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
    • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
    • F28D1/03—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
    • F28F9/02—Header boxes; End plates
    • F28F9/04—Arrangements for sealing elements into header boxes or end plates
    • F28F9/16—Arrangements for sealing elements into header boxes or end plates by permanent joints, e.g. by rolling
    • F28F9/18—Arrangements for sealing elements into header boxes or end plates by permanent joints, e.g. by rolling by welding
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S29/00—Metal working
    • Y10S29/037—Stamping with other step
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/4935—Heat exchanger or boiler making
    • Y10T29/49393—Heat exchanger or boiler making with metallurgical bonding
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/4998—Combined manufacture including applying or shaping of fluent material
    • Y10T29/49982—Coating

Definitions

  • the present invention is directed to a new method for manufacturing heat exchangers and, more particularly, cooling or heating radiators for vehicles, which has the great advantage of enabling the use of stainless steel for making the entire radiator or parts thereof so that the radiator may still, if necessary, comprise parts of cupreous metals. Furthermore, existing manufacturing equipment, such as the shaping tools and the assembling machines, may be used and with the certainty that the radiators thus produced will retain not only the same qualities, but also'improved qualities with respect to those made of brass and copper. This result is obtained while greatly reducing the manufacturing cost.
  • the method comprises the steps of taking a sheet or strip of stainless steel as the basic material, treating said sheet or strip to cover the faces thereof with a coating of non-ferrous metal or lead alloy and adapted to be wet by soldering alloys containing tin and lead, shaping said parts from the sheet or strip of coated stainless steel and assembling the parts of the radiator through a conventional soldering process.
  • a satisfactory procedure is to submit the stainless steel to an initial treatment comprising degreasing in an alkaline or acid bath, the composition of which may be variable. Baths used for degreasing ordinary iron sheets are perfectly satisfactory. Stainless steel is then submitted to a chemical pickling in a fluonitric aqueous bath which may contain from 2 to 10 percent of hydrofluoric acid and from 5 to 30 percent of nitric acid, this pickling being performed at ambient temperature. The sheets or strips of stainless steel thus depassivated may be stored in a dry room for a very long time.
  • the sheets or strips of stainless steel are submitted to a second pickling operation in a bath of the same kind asthe bath of the initial treatment, or preferably this second pickling is made by dipping in an aqueous bath containing 100 to g/liter of hydrochloric acid, i.e., a tri or quadrimolar bath.
  • the stainless steel is rinsed with fresh water, then immediately submitted to a fluxing operation by introduction into a molten salt bath containing 85 to parts by weight of zinc chloride and 15 to 25 parts by weight of ammonium chloride.
  • the steel As soon as the steel leaves the fluxing salt bath, it is passed or dipped into a molten bath containing from 8 to 40 parts per weight of tin and from 60 to 92 parts per weight of lead.
  • the sheets or strips are submitted to a powerful wiping action while the tin-lead alloy is still molten. This wiping action may be carried out by blowing hot air or by means of rolls or by a combination of these two opera tions.
  • the thickness of the alloy with a high percentage of lead which is thus deposited must be as thin as possible because it is only desired to form on the stainless steel surface a dependent coat suitable for subsequent wetting by soft solder. As the lower limit, a molecular coat is sufficient but in practice for convenience in manufacturing, this coat may be between about 0.5g. and in thickness.
  • the constitutive parts of the radiator are shaped by rolling with regard to the ducts, or by stamping with regard to collectors and water-boxes, only after the basic metal has been coated on the two faces thereof.
  • stamping it has been found that it is much easier to coat strips or continuous sheets of stainless steel with an added metal when said strips or sheets are not previously mechanically worked.
  • the stamping of stainless coated steel is made considerably easier by said coating alloy, the stamping operations particularly, can be made in a manner as simple and with the same tooling used for working non-ferrous alloys such as brass. This is generally not the case when parts are stamped from a non-coated stainless steel sheet.
  • the parts of coated stainless steel, made according to the invention may be fitted together, or with parts of other metals such as copper or brass, with exactly the same procedure as for assembling said parts of non-ferrous metals. Therefore, the parts are submitted to fluxing, then they are joined with a soft solder comprising a tin-lead alloy, the dependent coat covering both faces of the element of stainless steel thus ensuring the intimate connection with the soft solder.
  • the invention thus enables the manufacture of radiators of which all the elements may be made of stainless steel, thereby providing radiators having improved mechanical characteristics and making possible operation under higher pressure conditions for the water circuits. Moreover, this result is obtained at a lesser cost than for analogous radiators made of non-ferrous metals, for example brass.
  • a method of making products of which at least some parts are made from sheets of stainless steel which method includes the steps of providing a sheet of stainless steel containing no nickel and at least 13 percent by weight of chromium,
  • Method according to claim 1 comprising the further step of submitting the sheet, before deoxidizing, to degreasing, then to pickling in a fluonitric bath whereby the steel is depassivated.
  • step of deoxidizing the sheets includes subjecting the depassivated sheets to a pickling bath containing from three to four moles of acid by liter, then to a fluxing step in a molten bath containing zinc and ammonium chlorides.
  • step of covering includes dipping the fluxed sheet in a molten bath of a high lead percentage alloy, and wiping the sheet whereby the coating has a thickness between 0.541. and 201.1
  • a method of making products comprising at least some parts made from sheets of stainless steel and some portions of copper alloys, said stainless steel containing no nickel and at least 13 percent by weight of chromiurn, which method includes the steps of pickling the sheets of stainless steel in a fluonitric bath; keeping the pickled sheet in a dry atmosphere before use; at the moment of use;

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Coating With Molten Metal (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Abstract

The two faces of a sheet or thin strip of stainless steel are covered with a thin coating of lead, and is used for constituting the tubes, collector, water-boxes as well as the pipes of a radiator, and the parts thus made are soldered together with a tin-lead alloy by the same operational cycle as with corresponding parts made of brass or copper.

Description

United States Patent Chartet I Sept. 12, 1972 [54] METHOD OF FABRICATING AND SOLDERING STAINLESS STEEL PARTS [72] Inventor: Andre Chartet, Meudon, France [73] Assignee: Societe Anonyme Des Usines Chausson, Asnieres, France [22] Filed: June 23, 1970 [21] Appl. No.: 49,154
[30] Foreign Application Priority Data June 30, 1969 France ..6922044 [52] US. Cl ..29/157.3 R, 29/482, 29/502, 29/527.2, 29/DIG. 37
[51] int. Cl. ..B21d 53/02 [58] Field of Search ..29/157,3 R, 504, 502, 527.2, 29/DIG. 37, 482
[56] References Cited UNITED STATES PATENTS 3,128,546 4/1964 Schuster et al. ..29/504 X 2,498,827 2/1950 Shaw et al ..29/l57.3 R 2,937,438 5/l960 Lemon ..29/502 X 3,242,565 3/1966 North et al ..29/502 X 3,465,424 9/ l 969 Deringer .29/527.2
Primary Examiner-John F. Campbell Assistant ExaminerDonald C. Reiley, III Att0rneylmirie and Smiley [57] ABSTRACT 6 Claims, N0 Drawings METHOD OF FABRICATING AND SOLDERING STAINLESS STEEL PARTS BACKGROUND OF THE INVENTION It is well known that the methods for manufacturing products such as radiators are based upon the utilization of copper and copper alloys, principally red copper and brass, since those metals and alloys, are relatively corrosion resistant and moreover easy to shape for constituting tubes, collectors, water-boxes, pipes, etc. which are easy to secure together by soldering with alloys of lead and tin.
Copper and copper alloys are costly and attempts have been made to use more common metals, namely ferrous metals, but this introduces a very difficult metal corrosion problem. Therefore, although ordinary ferrous metals can be easily assembled by means of soldering, they have not been used except, at the most, for manufacturing cooling fins, i.e., indirect exchange surfaces which are never in contact with the liquid circulating in the heat exchanger.
Even for this restricted use of the manufacture of only the cooling fins, it is necessary to coat the outside of the core to protect said fins against rust. This coating is applied when the radiator is used in a motor vehicle even though the radiator is exposed to the protection of oil vapors, since in nearly all cases it is placed in the motor compartment of the vehicle.
Stainless ferrous alloys, namely stainless steels, have been known for a long time but up to now such steels could not practically be used in series made radiators even if their stainless state made them a priori usable for making collectors, water-boxes, and tubes for radiator cores, because soldering of stainless steels has been found very difficult. Actually, it is possible under certain conditions to connect two parts of stainless steel by soldering, but it is necessary previously to submit the parts to a very powerful pickling and fluxing step, and then to proceed immediately after with said soldering.
It has been found that in the manufacture of radiators, such a process could not be used since all of the soldering of a radiator can not simultaneously be made. Actually, if soldering of the ends of the tubes in the collectors could otherwise be effected, it would be difficult for the above-mentioned reasons and would induce, by using a stainless steel collector, the passivation of the non-soldered parts of the collectors on the ends of the tubes. Therefore, it would be necessary to submit the assembled cores once again to new pickling and fluxing operations in order to enable the soldering of a water-box on a collector made of stainless steel.
It is apparent that these very difficult and frequent operations result in a very high manufacturing cost. Moreover, it is difficult to stamp stainless steel and special tools are required for doing this work.
SUMMARY OF THE INVENTION The present invention is directed to a new method for manufacturing heat exchangers and, more particularly, cooling or heating radiators for vehicles, which has the great advantage of enabling the use of stainless steel for making the entire radiator or parts thereof so that the radiator may still, if necessary, comprise parts of cupreous metals. Furthermore, existing manufacturing equipment, such as the shaping tools and the assembling machines, may be used and with the certainty that the radiators thus produced will retain not only the same qualities, but also'improved qualities with respect to those made of brass and copper. This result is obtained while greatly reducing the manufacturing cost.
According to the invention, for making at least some of the parts of a radiator, the method comprises the steps of taking a sheet or strip of stainless steel as the basic material, treating said sheet or strip to cover the faces thereof with a coating of non-ferrous metal or lead alloy and adapted to be wet by soldering alloys containing tin and lead, shaping said parts from the sheet or strip of coated stainless steel and assembling the parts of the radiator through a conventional soldering process.
DETAILED DESCRIPTION OF THE INVENTION For the manufacture, according to the invention, of various parts of cooling and heating radiators for motor vehicles, for example water-boxes and connecting pipes, collectors on which said water-boxes have to be fixed, and, also, circulation tubes, 21 stainless steel is used which contains no nickel and a proportion of chromium of at least 13 percent; for example, a steel known under the name Z 8 C 17 of AFNOR classification may be used. The steel is submitted to a treatment in order to make possible the fitting together of the different parts of the radiator by means of solderings, namely tin-lead solderings.
A satisfactory procedure is to submit the stainless steel to an initial treatment comprising degreasing in an alkaline or acid bath, the composition of which may be variable. Baths used for degreasing ordinary iron sheets are perfectly satisfactory. Stainless steel is then submitted to a chemical pickling in a fluonitric aqueous bath which may contain from 2 to 10 percent of hydrofluoric acid and from 5 to 30 percent of nitric acid, this pickling being performed at ambient temperature. The sheets or strips of stainless steel thus depassivated may be stored in a dry room for a very long time.
During the proper treatment, the sheets or strips of stainless steel are submitted to a second pickling operation in a bath of the same kind asthe bath of the initial treatment, or preferably this second pickling is made by dipping in an aqueous bath containing 100 to g/liter of hydrochloric acid, i.e., a tri or quadrimolar bath. Following the second pickling, the stainless steel is rinsed with fresh water, then immediately submitted to a fluxing operation by introduction into a molten salt bath containing 85 to parts by weight of zinc chloride and 15 to 25 parts by weight of ammonium chloride.
As soon as the steel leaves the fluxing salt bath, it is passed or dipped into a molten bath containing from 8 to 40 parts per weight of tin and from 60 to 92 parts per weight of lead. At the output of the tin-lead bath, the sheets or strips are submitted to a powerful wiping action while the tin-lead alloy is still molten. This wiping action may be carried out by blowing hot air or by means of rolls or by a combination of these two opera tions. The thickness of the alloy with a high percentage of lead which is thus deposited must be as thin as possible because it is only desired to form on the stainless steel surface a dependent coat suitable for subsequent wetting by soft solder. As the lower limit, a molecular coat is sufficient but in practice for convenience in manufacturing, this coat may be between about 0.5g. and in thickness.
The constitutive parts of the radiator are shaped by rolling with regard to the ducts, or by stamping with regard to collectors and water-boxes, only after the basic metal has been coated on the two faces thereof. Actually, and surprisingly, it has been found that it is much easier to coat strips or continuous sheets of stainless steel with an added metal when said strips or sheets are not previously mechanically worked. Moreover, the stamping of stainless coated steel is made considerably easier by said coating alloy, the stamping operations particularly, can be made in a manner as simple and with the same tooling used for working non-ferrous alloys such as brass. This is generally not the case when parts are stamped from a non-coated stainless steel sheet.
The parts of coated stainless steel, made according to the invention, may be fitted together, or with parts of other metals such as copper or brass, with exactly the same procedure as for assembling said parts of non-ferrous metals. Therefore, the parts are submitted to fluxing, then they are joined with a soft solder comprising a tin-lead alloy, the dependent coat covering both faces of the element of stainless steel thus ensuring the intimate connection with the soft solder.
The invention thus enables the manufacture of radiators of which all the elements may be made of stainless steel, thereby providing radiators having improved mechanical characteristics and making possible operation under higher pressure conditions for the water circuits. Moreover, this result is obtained at a lesser cost than for analogous radiators made of non-ferrous metals, for example brass.
I claim:
1. A method of making products of which at least some parts are made from sheets of stainless steel, which method includes the steps of providing a sheet of stainless steel containing no nickel and at least 13 percent by weight of chromium,
deoxidizing the sheet of stainless steel, and immediately covering said deoxidized sheet on both faces thereof with a lead alloy in molten form, whereby the covered sheet is wettable by tin and lead solder,
forming parts of said product from the covered sheet,
assembling together the formed parts to constitute said product, and then tin and lead soldering the assembled parts.
2. Method according to claim 1, wherein the sheets are covered with a thincoat of a lead-tin alloy.
3. Method according to claim 1, comprising the further step of submitting the sheet, before deoxidizing, to degreasing, then to pickling in a fluonitric bath whereby the steel is depassivated.
4. Method according to claim 3, wherein the step of deoxidizing the sheets includes subjecting the depassivated sheets to a pickling bath containing from three to four moles of acid by liter, then to a fluxing step in a molten bath containing zinc and ammonium chlorides.
5. Method according to claim 4, wherein the step of covering includes dipping the fluxed sheet in a molten bath of a high lead percentage alloy, and wiping the sheet whereby the coating has a thickness between 0.541. and 201.1
. A method of making products comprising at least some parts made from sheets of stainless steel and some portions of copper alloys, said stainless steel containing no nickel and at least 13 percent by weight of chromiurn, which method includes the steps of pickling the sheets of stainless steel in a fluonitric bath; keeping the pickled sheet in a dry atmosphere before use; at the moment of use;
pickling the dried sheets in an aqueous bath with at a least one acid selected from the group consisting of fluonitric and hydrochloric acids;
rinsing the pickled sheets with water; and immediately after said rinsing, the further step of dipping the rinsed sheets in a bath containing a mixture of molten zinc and ammonium chlorides and then removing the sheets coated with the mixture of molten zinc and ammonium chlorides;
dipping the coated sheets in a bath containing a molten lead and tin mixture and then removing the sheets covered with the molten lead and tin mixture;
wiping the covered sheets of the excess of still molten tin and lead;
forming the parts from the wiped sheets and assembling the same with the portions of copper alloys into an assembled product;
submitting the assembled product to a soft fluxing with a flux of the type used in tin-lead soldering of copper members; and
heating the same to the soldering temperature.

Claims (5)

  1. 2. Method according to claim 1, wherein the sheets are covered with a thin coat of a lead-tin alloy.
  2. 3. Method according to claim 1, comprising the further step of submitting the sheet, before deoxidizing, to degreasing, then to pickling in a fluonitric bath whereby the steel is depassivated.
  3. 4. Method according to claim 3, wherein the step of deoxidizing the sheets includes subjecting the depassivated sheets to a pickling bath containing from three to four moles of acid by liter, then to a fluxing step in a molten bath containing zinc and ammonium chlorides.
  4. 5. Method according to claim 4, wherein the step of covering includes dipping the fluxed sheet in a molten bath of a high lead percentage alloy, and wiping the sheet whereby the coating has a thickness between 0.5 Mu and 20 Mu .
  5. 6. A method of making products comprising at least some parts made from sheets of stainless steel and some portions of copper alloys, said stainless steel containing no nickel and at least 13 percent by weight of chromium, which method includes the steps of pickling the sheets of stainless steel in a fluonitric bath; keeping the pickled sheet in a dry atmosphere before use; at the moment of use; pickling the dried sheets in an aqueous bath with at least one acid selected from the group consisting of fluonitric and hydrochloric acids; rinsing the pickled sheets with water; and immediately after said rinsing, the further step of dipping the rinsed sheets in a bath containing a mixture of molten zinc and ammonium chlorides and then removing the sheets coated with the mixture of molten zinc and ammonium chlorides; dipping the coated sheets in a bath containing a molten lead and tin mixture and then removing the sheets covered with the molten lead and tin miXture; wiping the covered sheets of the excess of still molten tin and lead; forming the parts from the wiped sheets and assembling the same with the portions of copper alloys into an assembled product; submitting the assembled product to a soft fluxing with a flux of the type used in tin-lead soldering of copper members; and heating the same to the soldering temperature.
US49154A 1969-06-30 1970-06-23 Method of fabricating and soldering stainless steel parts Expired - Lifetime US3689941A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR696922044A FR2045742B1 (en) 1969-06-30 1969-06-30

Publications (1)

Publication Number Publication Date
US3689941A true US3689941A (en) 1972-09-12

Family

ID=9036647

Family Applications (1)

Application Number Title Priority Date Filing Date
US49154A Expired - Lifetime US3689941A (en) 1969-06-30 1970-06-23 Method of fabricating and soldering stainless steel parts

Country Status (9)

Country Link
US (1) US3689941A (en)
JP (1) JPS502869B1 (en)
BE (1) BE752422A (en)
DE (1) DE2030925A1 (en)
ES (1) ES381193A1 (en)
FR (1) FR2045742B1 (en)
GB (1) GB1306835A (en)
NL (1) NL165669C (en)
SE (1) SE379946B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3838495A (en) * 1971-03-26 1974-10-01 Bayerische Motoren Werke Ag Method of forming closed sheet metal structures with an internal corrosion-resistant coating
US3963162A (en) * 1973-08-13 1976-06-15 Senju Metal Industry Co. Ltd. Method of soldering stainless steel pipes by using soft solders
FR2703282A1 (en) * 1993-03-31 1994-10-07 Lorraine Laminage Method of joining steel sheets clad with a layer of alloy principally comprising lead
USRE35098E (en) * 1979-12-20 1995-11-28 Modine Manufacturing Co. Method of making a heat exchanger
US5822854A (en) * 1994-07-22 1998-10-20 Mitsubishi Denki Kabushiki Kaisha Method of fabricating a heat exchanger for an air conditioner
US10010984B2 (en) 2013-10-31 2018-07-03 MAHLE Behr GmbH & Co. KG Method for the production of a heat exchanger, particularly a sorption heat exchanger

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1130790A (en) * 1979-12-20 1982-08-31 Zalman P. Saperstein Heat exchanger
ES487463A0 (en) * 1980-01-04 1980-11-01 Puma Chausson Radiadores PROCEDURE FOR THE MANUFACTURE OF HEAT EXCHANGERS, IN PARTICULAR RADIATORS
FR2549494B1 (en) * 1983-07-19 1989-03-24 Vaillant Sarl METHOD FOR SEALING CONSTRUCTION ELEMENTS HAVING COPPER AND STEEL SURFACES
DE102007038217A1 (en) 2007-08-13 2009-02-19 Behr Gmbh & Co. Kg Method for soldering a workpiece, device for carrying out the method and workpiece, soldered according to the method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2498827A (en) * 1945-10-01 1950-02-28 Young Radiator Co Oval oil cooler construction
US2937438A (en) * 1958-07-14 1960-05-24 Lloyd C Lemon Method for joining aluminum to stainless steel
US3128546A (en) * 1960-02-01 1964-04-14 Pennsalt Chemicals Corp Method and flux for soldering chromium oxide coated steel members
US3242565A (en) * 1963-02-06 1966-03-29 Robert E North Fluxless joining of stainless steel to aluminum
US3465424A (en) * 1967-01-26 1969-09-09 Smith Corp A O Method of forming glass coated steel articles

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2498827A (en) * 1945-10-01 1950-02-28 Young Radiator Co Oval oil cooler construction
US2937438A (en) * 1958-07-14 1960-05-24 Lloyd C Lemon Method for joining aluminum to stainless steel
US3128546A (en) * 1960-02-01 1964-04-14 Pennsalt Chemicals Corp Method and flux for soldering chromium oxide coated steel members
US3242565A (en) * 1963-02-06 1966-03-29 Robert E North Fluxless joining of stainless steel to aluminum
US3465424A (en) * 1967-01-26 1969-09-09 Smith Corp A O Method of forming glass coated steel articles

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3838495A (en) * 1971-03-26 1974-10-01 Bayerische Motoren Werke Ag Method of forming closed sheet metal structures with an internal corrosion-resistant coating
US3963162A (en) * 1973-08-13 1976-06-15 Senju Metal Industry Co. Ltd. Method of soldering stainless steel pipes by using soft solders
USRE35098E (en) * 1979-12-20 1995-11-28 Modine Manufacturing Co. Method of making a heat exchanger
FR2703282A1 (en) * 1993-03-31 1994-10-07 Lorraine Laminage Method of joining steel sheets clad with a layer of alloy principally comprising lead
US5822854A (en) * 1994-07-22 1998-10-20 Mitsubishi Denki Kabushiki Kaisha Method of fabricating a heat exchanger for an air conditioner
US5964284A (en) * 1994-07-22 1999-10-12 Mitsubishi Denki Kabushiki Kaisha Heat exchanger for air conditioner and method of fabricating the heat exchanger
US10010984B2 (en) 2013-10-31 2018-07-03 MAHLE Behr GmbH & Co. KG Method for the production of a heat exchanger, particularly a sorption heat exchanger

Also Published As

Publication number Publication date
DE2030925A1 (en) 1971-01-14
GB1306835A (en) 1973-02-14
FR2045742A1 (en) 1971-03-05
JPS502869B1 (en) 1975-01-29
NL7009673A (en) 1971-01-04
BE752422A (en) 1970-12-01
ES381193A1 (en) 1972-12-01
NL165669C (en) 1981-05-15
FR2045742B1 (en) 1974-02-22
SE379946B (en) 1975-10-27
NL165669B (en) 1980-12-15

Similar Documents

Publication Publication Date Title
EP0292565B1 (en) Process for manufacturing heat exchanger
US4831701A (en) Method of making a corrosion resistant aluminum heat exchanger using a particulate flux
US4891275A (en) Aluminum shapes coated with brazing material and process of coating
US3855682A (en) Method of soldering together an aluminum part and a ferrous or cuprous metal part
US4732311A (en) Process of producing lightweight and corrosion-resistant heat exchanger
US3689941A (en) Method of fabricating and soldering stainless steel parts
US5005285A (en) Method of producing an aluminum heat exchanger
DE59209228D1 (en) Process for producing a multilayer pipe made of metal
JP2001059183A (en) Chemical film from kf solution to aluminum for fluxless brazing
US4615952A (en) Aluminum shapes coated with brazing material and process of coating
US6120848A (en) Method of making a braze sheet
CA2591116A1 (en) Method of electroplating and pre-treating aluminium workpieces
US2646620A (en) Method of joining together the ends of thin-walled aluminum heat exchange tubes
US3728783A (en) Process for brazing stainless steel parts to parts of aluminum and aluminum alloys
US4705206A (en) Method for brazing a magnesium-containing aluminum alloy
JPS6334495A (en) Aluminum heat exchanger
JPH0688129B2 (en) Aluminum shaped article coated with brazing substance and coating method
JPS6174771A (en) Production of aluminum heat exchanger
JPS61246354A (en) Aluminum tube having many holes for heat exchanger and its manufacture
JPS63128163A (en) Zinc thickening treatment of surface layer of aluminum member
JPS61235072A (en) Production of aluminum heat exchanger
JP3153874B2 (en) Manufacturing method of corrosion resistant heat exchanger
JP2680763B2 (en) Aluminum shaped article coated with brazing material
CN113232381A (en) Aluminum alloy composite plate with non-corrosive brazing flux and preparation method thereof
JPH01212749A (en) Manufacture of surface modified copper-alloy bar