CA1313291C - Method of producing a metallic interface - Google Patents
Method of producing a metallic interfaceInfo
- Publication number
- CA1313291C CA1313291C CA000573752A CA573752A CA1313291C CA 1313291 C CA1313291 C CA 1313291C CA 000573752 A CA000573752 A CA 000573752A CA 573752 A CA573752 A CA 573752A CA 1313291 C CA1313291 C CA 1313291C
- Authority
- CA
- Canada
- Prior art keywords
- alloy
- zone
- reduced
- arise
- diffusion
- 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 - Fee Related
Links
Classifications
-
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/24—Preliminary treatment
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Pressure Welding/Diffusion-Bonding (AREA)
Abstract
ABSTRACT
A method for producing a metallic interface suitable for overlaying Consists of exposing the area of an alloy combination to be overlayed to a temperature above its lower critical until an element reduced zone arises. This element reduced zone more easily accepts element diffusion that takes place during overlaying.
Accordingly, an improved interface, one that is more ductile and less prone to cracking, is produced.
A method for producing a metallic interface suitable for overlaying Consists of exposing the area of an alloy combination to be overlayed to a temperature above its lower critical until an element reduced zone arises. This element reduced zone more easily accepts element diffusion that takes place during overlaying.
Accordingly, an improved interface, one that is more ductile and less prone to cracking, is produced.
Description
METHOD OF PRODUCING A ~ETALLIC INTERFACE
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a method for producing a more desirable meta11urgical bond when applying dissimilar metals by such thermal processes as welding, hot isostatic pressing (HIP) and 05 diffusion.
DescriPtion of the Prior Art Many alloy combinations used in various bonding processes tend to produce interfaces that have undesirable metallurgical and mechanical characteristics. A primary cause of these undesirab~
characteristics is element diffusion between alloy systems. Such element diffusion causes a zone of varying thickness, including aiffused elements from both systems, to arise between involved alloy systems.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings of the prior art by providing a method of producing a compatible metallic inter,ace between dissimilar metal systems being thermally joined.
In its broadest terms, the present invenlion comprises ~he step Gf ; causing a reduced element zone to arise between the dissimilar metals immediately before bonding. In a more narrowly defined embodiment9 the method of the present invention is thermal in nature, involvirlg , exposing a portion of one of the dissimilar metals, an alloy combination, to a temperature above its lower critical. Such exposure is maintained for a period of time sufficient to cause surface diffusion of at least one of the constituent alloy elements.
05 This, in effect, products a surface zone reduced in alloy content that can more easily accept element diffusion which is known to take place during bonding. Production of such a surface zone leads directly to an interface with less total alloy, less residual stresses, increased ductility and decreased proneness to cracking.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be more fully described, by way of example, with reference to the accompanying drawing in which the sole figure is a microphotograph of a cross-section of an interface produced by the method of the present invention.
DESCRIPTION OF THE INVENTION
EXAMPLE
A typical example of the ~ethod o~ the present invention would be HIP cladding of Inconel 625 to an alloy s~eel system such as 2-1/2 Cr-lMo. The figure shows such a steel sysLem after execution of the method of the present invention. Three cle~rly d-fined are~s can be seen in the figure. The darkest area, on the far righ~, is th-; surface of the steel system to which Inconel 625 could be HIP clad~
In accordance with the teachings of the present invention, that surface is exposed to a temperature above the known lower critical temperature for a 2-1/2 CR-lMo alloy steel system. Such exposure is :, : , ' ` ` ~ ' .. '~
, . ~ .
~, ............ .
131~291 maintained until, as can be seen with further reference to the figure, an element reduced zone (the light rectangular area) is caused to form. Of course, uniform exposure of the surface of the steel system causes such a uniform deep zone to form, which, because 05 of such factors as predictability of strength, would be desirable in most c~ses. This element reduced zone, because of the surface diffusion of at least one element which has taken place therein, has reduced alloy content compared to the remaining portion of the steel system, the rectangular area to the left in the figure. Because of this reduced in alloy content, the element reduced zone can more easily accept element diffusion that is known to invariably take place during overlaying, cladding and similar bonding operationsO
Desirab1e characteristics of such an interface have been found to include increased ductility and decreased proneness to crackinS~
Further, less residual stresses have been found within such interfaces and heat treatability is more predictable, making interface hardness easier to control and more suitable for H2S type service.
The invention is not limited to the example s-t for n above.
2D The s ope of the invention is defined by the following clalms.
. ... ~ ,
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a method for producing a more desirable meta11urgical bond when applying dissimilar metals by such thermal processes as welding, hot isostatic pressing (HIP) and 05 diffusion.
DescriPtion of the Prior Art Many alloy combinations used in various bonding processes tend to produce interfaces that have undesirable metallurgical and mechanical characteristics. A primary cause of these undesirab~
characteristics is element diffusion between alloy systems. Such element diffusion causes a zone of varying thickness, including aiffused elements from both systems, to arise between involved alloy systems.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings of the prior art by providing a method of producing a compatible metallic inter,ace between dissimilar metal systems being thermally joined.
In its broadest terms, the present invenlion comprises ~he step Gf ; causing a reduced element zone to arise between the dissimilar metals immediately before bonding. In a more narrowly defined embodiment9 the method of the present invention is thermal in nature, involvirlg , exposing a portion of one of the dissimilar metals, an alloy combination, to a temperature above its lower critical. Such exposure is maintained for a period of time sufficient to cause surface diffusion of at least one of the constituent alloy elements.
05 This, in effect, products a surface zone reduced in alloy content that can more easily accept element diffusion which is known to take place during bonding. Production of such a surface zone leads directly to an interface with less total alloy, less residual stresses, increased ductility and decreased proneness to cracking.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be more fully described, by way of example, with reference to the accompanying drawing in which the sole figure is a microphotograph of a cross-section of an interface produced by the method of the present invention.
DESCRIPTION OF THE INVENTION
EXAMPLE
A typical example of the ~ethod o~ the present invention would be HIP cladding of Inconel 625 to an alloy s~eel system such as 2-1/2 Cr-lMo. The figure shows such a steel sysLem after execution of the method of the present invention. Three cle~rly d-fined are~s can be seen in the figure. The darkest area, on the far righ~, is th-; surface of the steel system to which Inconel 625 could be HIP clad~
In accordance with the teachings of the present invention, that surface is exposed to a temperature above the known lower critical temperature for a 2-1/2 CR-lMo alloy steel system. Such exposure is :, : , ' ` ` ~ ' .. '~
, . ~ .
~, ............ .
131~291 maintained until, as can be seen with further reference to the figure, an element reduced zone (the light rectangular area) is caused to form. Of course, uniform exposure of the surface of the steel system causes such a uniform deep zone to form, which, because 05 of such factors as predictability of strength, would be desirable in most c~ses. This element reduced zone, because of the surface diffusion of at least one element which has taken place therein, has reduced alloy content compared to the remaining portion of the steel system, the rectangular area to the left in the figure. Because of this reduced in alloy content, the element reduced zone can more easily accept element diffusion that is known to invariably take place during overlaying, cladding and similar bonding operationsO
Desirab1e characteristics of such an interface have been found to include increased ductility and decreased proneness to crackinS~
Further, less residual stresses have been found within such interfaces and heat treatability is more predictable, making interface hardness easier to control and more suitable for H2S type service.
The invention is not limited to the example s-t for n above.
2D The s ope of the invention is defined by the following clalms.
. ... ~ ,
Claims (6)
1. A method for producing an improved metallurgical bond between dissimilar metals, comprising the step of causing an element reduced zone to arise between the dissimilar metals immediately before bonding.
2. The method of Claim 1 wherein the element reduced zone is caused to arise thermally.
3. The method of Claim 2 wherein at least one of the dissimilar metals comprises an alloy combination having a surface to which another dissimilar metal is to be joined and wherein the reduced element zone is cause to arise by the step of heating the surface until surface diffusion of at least one of the constituent elements is caused.
4. A method for joining together dissimilar metals of which at least one comprises an alloy and which has a surface to which the other metal is to be applied, said method comprising the steps of:
heating the surface of the alloy until surface diffusion at least one of the constituent alloy elements causes a surface zone reduced in alloy content to arise; and applying the other metal to the surface zone reduced in alloy content.
heating the surface of the alloy until surface diffusion at least one of the constituent alloy elements causes a surface zone reduced in alloy content to arise; and applying the other metal to the surface zone reduced in alloy content.
5. The method of Claim 4 wherein the step of heating the surface further comprises uniformly heating the surface so that the surface zone reduced in alloy content which arises is of uniform depth.
6. A method for preparing an alloy combination for overlaying, said alloy combination having a lower critical temperature and a surface to be overlayed, said method comprising the steps of:
exposing the surface of the alloy combination to a temperature above its lower critical; and maintaining exposure of the surface of the alloy combination to a temperature above its lower critical until diffusion of at least one of the constituent alloy elements takes place throughout the entire surface.
exposing the surface of the alloy combination to a temperature above its lower critical; and maintaining exposure of the surface of the alloy combination to a temperature above its lower critical until diffusion of at least one of the constituent alloy elements takes place throughout the entire surface.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US8877887A | 1987-08-24 | 1987-08-24 | |
| US088,778 | 1987-08-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1313291C true CA1313291C (en) | 1993-02-02 |
Family
ID=22213400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000573752A Expired - Fee Related CA1313291C (en) | 1987-08-24 | 1988-08-03 | Method of producing a metallic interface |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPH01154885A (en) |
| AU (1) | AU648013B2 (en) |
| CA (1) | CA1313291C (en) |
| GB (1) | GB2208819B (en) |
| NO (1) | NO883764L (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59113989A (en) * | 1982-12-20 | 1984-06-30 | Hitachi Ltd | Diffusion joining method |
| FR2594367B1 (en) * | 1986-02-19 | 1988-04-29 | Cegedur | METHOD OF HOT PLATING BY COLAMINATION OF LI CONTAINING ALLOYS |
-
1988
- 1988-08-03 CA CA000573752A patent/CA1313291C/en not_active Expired - Fee Related
- 1988-08-05 GB GB8818666A patent/GB2208819B/en not_active Expired - Fee Related
- 1988-08-18 AU AU21093/88A patent/AU648013B2/en not_active Ceased
- 1988-08-22 JP JP63207996A patent/JPH01154885A/en active Pending
- 1988-08-23 NO NO88883764A patent/NO883764L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| NO883764D0 (en) | 1988-08-23 |
| GB2208819A (en) | 1989-04-19 |
| JPH01154885A (en) | 1989-06-16 |
| NO883764L (en) | 1989-02-27 |
| AU648013B2 (en) | 1994-04-14 |
| AU2109388A (en) | 1989-03-02 |
| GB8818666D0 (en) | 1988-09-07 |
| GB2208819B (en) | 1991-04-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3957194A (en) | Liquid interface diffusion method of bonding titanium and/or titanium alloy structure | |
| JPH0341428B2 (en) | ||
| JPS6341970B2 (en) | ||
| EP0171230A1 (en) | Diffusion bonding by hot isostatic pressure | |
| US4811892A (en) | Method for diffusion welding under isostatic pressure | |
| US5000371A (en) | Method of producing a metallic interface | |
| JPS5842703A (en) | Manufacture of preform of one body powder alloy part from more than two kinds of powder alloy | |
| JPS5948714B2 (en) | Method of pressure welding metal base materials using eutectic reaction | |
| CA1313291C (en) | Method of producing a metallic interface | |
| JP2003524143A (en) | Cooling element and method for manufacturing cooling element | |
| US2169354A (en) | Method of and means for producing steel clad with stainless steel | |
| IE66339B1 (en) | Wire drawing die | |
| JPS58128281A (en) | Diffusion bonding method of sintered hard alloy and steel | |
| Johnson | Preparation of Metallic Interface | |
| GB2075554A (en) | Production of powdered metal articles | |
| JPS5890385A (en) | Manufacture of composite wear resistance member | |
| JPS6119705A (en) | Formation of hard metal layer onto surface of metal | |
| JPS561286A (en) | Production of ti-clad steel | |
| JPS6453765A (en) | Method for joining cast iron pipe to flange member | |
| US4050620A (en) | Method of welding a friction material to a reinforcing member | |
| JPS6349381A (en) | Insert material for diffused joining | |
| EP1887101A1 (en) | Production method for tin targets used in magnetron sputtering coating of glass | |
| JPH02224889A (en) | Method for welding stainless steel and different metal | |
| JPS61139682A (en) | Formation of alloy on metallic surface with laser | |
| Sasaki et al. | Diffusion bonding system with an amorphous insert metal for steel bars |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |