GB2071552A - The Treatment of Metals - Google Patents
The Treatment of Metals Download PDFInfo
- Publication number
- GB2071552A GB2071552A GB8006888A GB8006888A GB2071552A GB 2071552 A GB2071552 A GB 2071552A GB 8006888 A GB8006888 A GB 8006888A GB 8006888 A GB8006888 A GB 8006888A GB 2071552 A GB2071552 A GB 2071552A
- Authority
- GB
- United Kingdom
- Prior art keywords
- metal
- affected zone
- heat affected
- charge
- treatment
- 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.)
- Withdrawn
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 31
- 239000002184 metal Substances 0.000 title claims abstract description 31
- 238000011282 treatment Methods 0.000 title claims description 15
- 150000002739 metals Chemical class 0.000 title description 11
- 238000000034 method Methods 0.000 claims abstract description 22
- 239000002360 explosive Substances 0.000 claims abstract description 11
- 238000004880 explosion Methods 0.000 claims abstract description 8
- 239000000956 alloy Substances 0.000 claims description 15
- 229910045601 alloy Inorganic materials 0.000 claims description 15
- 238000003466 welding Methods 0.000 claims description 12
- 230000004927 fusion Effects 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 description 5
- 238000002635 electroconvulsive therapy Methods 0.000 description 5
- 230000032683 aging Effects 0.000 description 4
- 239000004411 aluminium Substances 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 210000001503 joint Anatomy 0.000 description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- 238000005474 detonation Methods 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910018182 Al—Cu Inorganic materials 0.000 description 1
- 229910018464 Al—Mg—Si Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000010273 cold forging Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000000123 paper Substances 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
- -1 welded joints Chemical class 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D10/00—Modifying the physical properties by methods other than heat treatment or deformation
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Pressure Welding/Diffusion-Bonding (AREA)
Abstract
A method of treating the heat affected zone associated with a welded joint in a metal structure includes placing a controlled explosive charge close to the structure and detonating the charge so that substantially all of the heat affected zone is mechanically and thermally affected by explosion of the charge in such a way that its mechanical properties are improved.
Description
SPECIFICATION
The Treatment of Metals
The present invention relates to the treatment of metals.
When metals (including alloys) are welded they can suffer an immediate degradation of their yield stress and hardness in the zone affected by the heat of the welding process hereinafter referred to as the HAZ (heat affected zone). This problem is most serious in:
i. those metals which are age hardened and derive part of their strength from the presence of a controlled distribution of fine particles produced by a prescribed thermal/mechanical treatment; examples are alloys consisting mainly of aluminium and based on the Al-Cu, Al-Mg-Si, Al
Mg-Zn systems, as well as maraging steels;
ii. work hardened alloys such as those of aluminium and magnesium containing up to about 7% magnesium;
iii. single phase metals such as copper, aluminium and iron which produce regions of grain growth in the HAZ on welding.
The metals listed in categories (i) to (iii) above are normally given mechanical and/or thermal treatment after welding to restore the mechanical properties of the HAZ to those of the parent metal, i.e. the levei for those parts unaffected by the welding process. For example, alloys in category (i) are normally given a post-weld heat treatment, but this can be very costy and also difficult to apply in the case of large metal structures. Alloys in category (ii) recrystallise after welding and are normally treated by further cold forging, but this usually involves a considerable change in shape of the piece being treated to restore its strength to that of the parent alloy.
Metals in category (iii) are normally given postweld thermal/mechanical treatments to refine the grain size and restore the strength level to that of the parent metal. These treatments can be costly.
According to the present invention in a first aspect a method of treating the heat affected zone associated with a welded joint in a metal structure includes placing a controlled explosive charge close to the structure and detonating the charge so that substantially all of the heat affected zone is mechanically and thermally affected by explosion of the charge in such a way that its mechanical properties are improved.
The improvement may be immediately after the explosion and/or after subsequent ageing.
The metal of the structure may be one of those listed in categories (i) to (iii) above.
The explosive may, for example, be a low detonation velocity, powdered explosive such as
Trimonite 1 (Trade Mark) for the treatment of thin sheets of soft metals (eg less than 10 mm thick) or a higher detonation velocity explosive such as
RDX (Trade Mark) in a plastic matrix for the treatment of thicker plates particularly of harder metals.
The charge may be in contact with the structure or a distance away, typically up to 6 mm, sufficiently small that the metal in the HAZ is affected by the explosion of the charge.
The method improves the hardness, yield strength and ultimate tensile strength of the HAZ.
Preferably the explosion additionally affects the fusion zone, if welding is by one of the conventional fusion welding methods (filler metal) of the welded joint in which case the hardness, yield strength and ultimate tensile strength of that zone are also improved.
One or more subsequent heat treatments to the structure may or may not be necessary depending on the particular metal(s) involved.
The method is more attractive than the known methods mentioned above because: (a) no permanent change in the shape of the piece needs to take place after welding; (b) a range of strength levels to suit a particular application is available simply by varying the amount of explosive used; (c) the time and/or temperature and hence cost of any further heat treatment are reduced because the need for such further treatment is reduced, and (d) the method may be applied to metal structures which have previously been considered impractical to weld or to treat after welding because of their shape or size.
According to the present invention in a second aspect there is provided a structure of metal having at least one welded joint, substantially all of the heat affected zone associated with the joint having been treated by the method according to the first aspect.
The treatment of metals, including welded joints, by the detonation of an adjacent explosive charge is known. However, such treatments have not been carried out in order to improve hardness, yield strength and ultimate tensile strength and consequently have not involved improving these properties in substantially all of the HAZ.
Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:
Figure 1 is a cross-sectional end elevation of an arrangement for treating a welded butt joint in a metal structure by explosive according to a method embodying the present invention.
Figure 2 is a plan view of the arrangement shown in Figure 1.
Figures 3 and 4 are graphs of hardness v ageing time at 2930K and 3630K respectively of simulated welded alloy structures, each of which compares the effect of treatment of welded alloy structures by a method embodying the invention with that of a known method.
In Figures 1 and 2 a welded butt joint in an alloy structure 1 is shown comprising alloy sections 2 and 3 which have been previously welded together by a fusion zone 5 of filler metal.
The HAZ (heat affected zone) resulting from the formation of the welded joint is indicated by dashed lines 6. The alloy structure 1 is mounted on a steel anvil 7. A cardboard enclosure 9 which encompasses the HAZ 6 is placed on top of the structure 1. A charge 11 of explosive is contained in the enclosure in contact with the structure 1 in the HAZ 6 and fusion zone 5. A detonator fuse 13 comprising touch paper is fitted through a hole in the enclosure 9 and into the charge 11.
When the fuse 13 is detonated the charge 11 is exploded to provide a controlled mechanical and thermal shock treatment to the HAZ 6 and the fusion zone 5 of the structure 1 to improve the mechanical properties of these regions as outlined above.
A specific example of an alloy structure which was treated in the manner described with reference to Figure 1 is as follows. The sections in the structure which were welded together were 10 mm thick sections of an alloy containing 4.2% by weight of zinc, 2.5% by weight of magnesium, the remainder being essentially of aluminium. A layer of Trimonite 1 explosive 6 mm thick was used to provide the shock treatment. The joint was then aged in air at about 2730K.
Figure 2, curve A, illustrates the resulting hardness of the HAZ of the sections as a function of time at 2730K, determined on simulated welded specimens. This may be compared with curve B in Figure 2 which is the corresponding curve obtained by ageing in air at 2730K of similar simulated jointed sections without the shock treatment i.e. by a conventional treatment.
A similar structure was treated in the same way again with the shock treatment but was aged not at 2730K but instead of about 3630K. The hardness obtained as a function of time is shown as curve A in Figure 3 and may be compared with curve B which illustrates the corresponding curve obtained by ageing a similar structure at 3630K without the shock treatment, i.e. by a conventional treatment.
Other kinds of welded joints may be treated in a way similar to that described above.
Claims (8)
1. A method of treating the heat affected zone associated with a welded joint in a metal structure including placing a controlled explosive charge close to the structure and detonating the charge so that substantially all of the heat affected zone is mechanically and thermally affected by explosion of the charge in such a way that its mechanical properties are improved.
2. A method as claimed in claim 1 and wherein the metal of the heat affected zone is an age hardened alloy.
3. A method as claimed in claim 1 and wherein the metal of the heat affected zone is a work hardened alloy.
4. A method as claimed in claim 1 and wherein the metal is a single phase metal.
5. A method as claimed in any one of the preceding claims and wherein the explosion additionally affects the fusion zone, the welding of the welding of the welded joint having been carried out by a conventional fusion welding method.
6. A method as claimed in claim 2 and wherein a further heat treatment is applied to the metal structure including the heat affected zone after the explosion step.
7. A method as claimed in claim 1 and substantially the same as any one of the specific treatments described hereinbefore.
8. A structure of metal having at least one welded joint, the heat affected zone associated with the joint having been treated by the method claimed in any one of the preceding claims.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8006888A GB2071552A (en) | 1980-02-29 | 1980-02-29 | The Treatment of Metals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8006888A GB2071552A (en) | 1980-02-29 | 1980-02-29 | The Treatment of Metals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2071552A true GB2071552A (en) | 1981-09-23 |
Family
ID=10511773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8006888A Withdrawn GB2071552A (en) | 1980-02-29 | 1980-02-29 | The Treatment of Metals |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2071552A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2154492A (en) * | 1984-02-22 | 1985-09-11 | Odonnell & Ass | Mechanical stress improvement process |
| US4612071A (en) * | 1984-02-22 | 1986-09-16 | O'donnell & Associates, Inc. | Mechanical stress improvement process |
| US4683014A (en) * | 1986-03-28 | 1987-07-28 | O'donnell & Associates, Inc. | Mechanical stress improvement process |
| CN106670674A (en) * | 2016-12-13 | 2017-05-17 | 西安交通大学 | Method for determining positions of all areas of cross section of industrial pure-titanium fusion welding joint |
| FR3137600A1 (en) * | 2022-07-07 | 2024-01-12 | Constellium Issoire | Process for manufacturing a final aluminum alloy panel |
-
1980
- 1980-02-29 GB GB8006888A patent/GB2071552A/en not_active Withdrawn
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2154492A (en) * | 1984-02-22 | 1985-09-11 | Odonnell & Ass | Mechanical stress improvement process |
| US4612071A (en) * | 1984-02-22 | 1986-09-16 | O'donnell & Associates, Inc. | Mechanical stress improvement process |
| US4683014A (en) * | 1986-03-28 | 1987-07-28 | O'donnell & Associates, Inc. | Mechanical stress improvement process |
| CN106670674A (en) * | 2016-12-13 | 2017-05-17 | 西安交通大学 | Method for determining positions of all areas of cross section of industrial pure-titanium fusion welding joint |
| CN106670674B (en) * | 2016-12-13 | 2019-06-11 | 西安交通大学 | A method for determining the position of each zone in the cross section of an industrial pure titanium fusion welded joint |
| FR3137600A1 (en) * | 2022-07-07 | 2024-01-12 | Constellium Issoire | Process for manufacturing a final aluminum alloy panel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3850698A (en) | Altering material properties | |
| Clauer et al. | Interaction of laser-induced stress waves with metals | |
| ZA894717B (en) | Process for direct shaping and optimisation of the mechanical characteristics of penetrating projectiles of high-density tungsten alloys | |
| RU2000111480A (en) | Small-caliber non-toxic projectile | |
| US4582544A (en) | Production of metallic articles | |
| EP0040011B1 (en) | Arrangements for igniting a pyrotechnic charge | |
| GB2071552A (en) | The Treatment of Metals | |
| JPH01157785A (en) | Method of explosive-welding alloy aluminum | |
| US5531369A (en) | Process for making machines resistant to cavitation and liquid droplet erosion | |
| WO2020049027A1 (en) | Method of producing a high-energy hydroformed structure from a 7xxx-series alloy | |
| RU2074074C1 (en) | Method of explosion welding of thin sheet blanks | |
| US3791881A (en) | Annealing treatment for controlling warhead fragmentation size distribution | |
| US3994752A (en) | Annealing treatment for controlling warhead fragmentation size distribution | |
| JPS6479320A (en) | Improvement of material quality of metal for welding austenitic stainless steel | |
| EP1433866A2 (en) | Crash resistant aluminium alloy sheet products and method of making same | |
| Van Der Hoeven et al. | A new 5xxx series alloy developed for automotive applications | |
| Kosturek et al. | Research on the post-weld explosive hardening of AA7075-T651 friction stir welded butt joints | |
| Mulford et al. | Preshock desensitization of PBX explosives | |
| Liu | Microstructure and mechanical properties of tin-based alloys for miniature detonating cords | |
| US1913394A (en) | Material for welding wrought aluminum alloys | |
| RU2239528C1 (en) | Method for making steel-copper composition material | |
| Hargreaves et al. | Adiabatic shear-an annotated bibliography | |
| Gray | Factors influencing the environmental behaviour of aluminum-lithium alloys | |
| Nicholson et al. | The Effect of Heat Treatment on the Structure and Mechanical Properties of a Complex Austenitic Weld Metal | |
| Gates | Aluminum Alloy Welding and Stress-Corrosion Testing |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |