Production of metal strip
9 claims: 4 independent, 5 dependent
- 1Patentkrav :1. . Fremgangsmåte for kontinuerlig fremstilling av metallbånd fra pulver, omfattende kontinuerlig sammenpressing av pulver for å danne et sammenhengende råpulverbånd, kontinuerlig transport av råpulverbåndet til innløpet i en sinterovn, drift av båndet gjennom ovnen ved hjelp av klemvalser som er anordnet nedstrøms av ovnen, og understøttelse av båndet på en gasspute under dets transport gjennom ovnen, karakterisert ved at råpulverbåndet idet det innføres i sinterovnen isoleres fra strekkspenninger som båndet utsettes for oppstrøms av sinterovnen, og at båndet tillates å krympe lineært under sintringen i ovnen ved at det sintrede bånd trekkes fra ovnen med en hastighet som er så mye lavere enn den hastighet med hvilken det føres til ovnen at det tilsvarer den lineære reduksjon av båndet når det krymper under gjennomløp i ovnen.
- 2Fremgangsmåte ifølge krav 1, karakterisert ved at råpulverbåndet understøttes ved hjelp av et flytebord (5) før det innføres i sinterovnen (6).
- 3Fremgangsmåte ifølge krav 1 eller 2, karakterisert ved at råpulverbåndet drives gjennom sinterovnen ved hjelp av to samvirkende uttrekksvalser (7, 7) som er plassert ved utløpet av sinterovnen.
- 4Fremgangsmåte ifølge krav 3, karakterisert ved at råpulverbåndet mates inn i sinterovnen ved hjelp av to samvirkende klemvalser (4, 4), og at de respektive hastigheter for klemvalsene (4, 4) og uttrekksvalsene (7, 7) samordnes slik i forhold til hverandre at strekkspenningen som påføres båndet under dets passasje gjennom sinterovnen, blir i hovedsaken null.
- 5Fremgangsmåte ifølge krav 3, karakterisert ved at råpulverbåndet mates over i det minste en del av omkretsflaten på en roterende friksjonstrommel (30), og at rotasjonshastighetene for uttrekksvalsene (32-32) og friksjonstrommelen samordnes slik i forhold til hverandre at strekkspenningen som påføres båndet under dets passasje gjennom sinterovnen, blir i hovedsaken null.
- 6Fremgangsmåte ifølge krav 2 og 3, karakte r i s e r t ved at overflaten på flytebordet (35) er krummet og nedad hellende og at rotasjonshastigheten for uttrekksvalsene (37, 37) reguleres i avhengighet av spenningen i båndet når det passerer over flytebordet, slik at strekkspenningen som påføres båndet under dets passasje gjennom sinterovnen, blir i hovedsaken null.
- 7Fremgangsmåte ifølge et av de foregående krav, hvor råpulverbåndet sammenpresses av et ferritisk rustfritt stålpulver, karakterisert ved at den strekkspenning som påføres båndet under dets passasje gjennom sinterovnen, er mindre enn 50 000 Pa (N/m^).
- 8Fremgangsmåte ifølge et av de foregående krav, hvor råpulverbåndet sammenpresses av et austenitisk, rustfritt stålpulver, karakterisert ved at den strekkspenning som påføres båndet under dets passasje gjennom sinterovnen, er 2 mindre enn 70 000 Pa (N/m ).
- 9Fremgangsmåte ifølge krav 7, karakterisert ved at den strekkspenning som påføres båndet, er mindre enn 10 000 Pa (N/m .
Independent claims9
67 paragraphs in 1 section, as filed
<img file="NO140288B_D0001.tif" />
[B] (11) EXPRESSION WRITING <Nf. 140288
NORWAY [NO]
BOARD
FOR THE INDUSTRIAL R EKS PROTECTION (51) Int. Cl.<sup>5</sup> B 22 F 3/18
<td> (21)</td><td>Patent application no.</td><td> 741581</td>
<td> (22)</td><td>filed</td><td> 02.05.74</td>
<td> (23)</td><td>Løpedag</td><td> 02.05.74</td>
(41) Generally available from (44) The application laid out, pamphlet expense
05.11.74
30.04.79 (30) Priority requested
03.05.73, 31.01.74, United Kingdom, Nos. 21103/73, 4500/74
<td>(54) Designation of the invention</td><td>Process for continuous manufacture of metal strips, strips, etc. of a powder material</td>
<td>(71) (73) Applicant / Patent Holder</td><td>BRITISH STEEL CORPORATION, 33 Grosvenor Place, London SWl, England.</td>
<td>(72) Inventor</td><td>GEORGE JACKSON, Sheffield, Yorkshire, TERENCE FIELDSEND, Wickersley, Rotherham, Yorkshire, England. Siv. ing. Ole J. Aarflot,</td>
<td>(74) Agent</td><td>Bryn & Aarflot A / S, Oslo.</td>
<td>(56) Cited publications</td><td>British (GB) Patent No. 996199 US Patent Nos. 3122434 (75-214), 3198499 (263-3)</td>
The invention relates to continuous fabrication of metal strips and is particularly directed to the manufacture of steel strips by pressing roll of metal powder.
Processes for the continuous manufacture of metal strips and other forms of compression of metal powders have previously been proposed. In these processes, cold pressing alone is not enough to produce a belt of density and strength approaching the same as that of a belt rolled from a bar. It is necessary to sinter the compressed powder, that is, it is heated to a temperature at which the powder will bond by an initial melting or diffusion in solid form at the high temperature. The sintering can be followed by further compression and heat treatments to obtain a strip with appropriate mechanical properties and surface finish. By means of these previously proposed methods, strips of sufficient density and with mechanical properties comparable to strips rolled from a bar can be produced.
Ideally, the tape should be sintered in a continuous oven, and to prevent the tape from collapsing, it must be supported to some extent while it is in the oven. It has been proposed to use a support in the form of an endless metal belt running through the furnace.
Attempts to fabricate metal strips in this way have presented major problems. When sintering the belt while supported on a metal strap, the belt does not get the desired mechanical properties because the tensile stresses applied to the compressed powder mass during sintering and caused by the belt will prevent contraction or shrinkage of the belt as it passes through the sinter furnace. The frictional resistance that occurs between the belt and the belt, especially when contracted, will result in a poorly effective sintering, resulting in surface2 cracking of the belt upon subsequent rolling.
Tests have shown that when sintering raw powder bands formed from compressed metal powder, the tensile stress in the band must be less than 70 kN / m for austenitic acid-resistant steel and less than 50 kN / m for ferritic acid-resistant steel. These are maximum allowable voltages. If they are exceeded, surface cracks will appear on the tape. Lower stresses can have a certain effect on the toughness of the product and for the best quality finished bands the stresses should be kept below 15 kN / m for austenitic and 10 kN / m for ferritic acid-resistant steels.
It is known, inter alia, from US Pat. No. 3,122,434 to regulate the strain in a coil supported roller powder band which is passed through a sinter furnace between a press roll pair and a squeeze roll pair arranged on the feed side and the outlet side of the furnace, respectively. The adjustment is effected by an unsupported length of the band between the press roll pair and the furnace being monitored by a control device which affects the rotational speeds of the two roll pairs depending on the band length deviation from a predetermined path. Purely except that the rollers' only partial support of the powder band during the feed through the furnace is likely to give rise to unacceptable tensile stresses in spite of the regulation, the tensile stress in the unsupported band length in front of the furnace entrance will certainly exceed that which can be allowed to the maximum. voltage-free sintering.
U.S. Patent No. 3,198,499 further discloses a system for gas-assisted conveying of tape or plate-shaped material in connection with heat treatment, in which the tape is subjected to less tensile stresses than conventional belt or roller conveyors. However, the belt is subjected to considerable tensile load before being supported on the gas pad, and although the system works fully satisfactorily for rolled material and the like, it will thus exhibit the same weakness as the device of sintering powder powder strips of the device of the aforementioned U.S. Patent 3,122 434, the stress or strain problem that must be overcome by sintering the compressed powder band is considerably greater than that encountered in heat treatment of e.g. rolled or forged tape and plate.
The object of the present invention is to provide a method of continuous sintering of metal powder strips, during which the tensile stresses applied to the strip during its passage through the sintering furnace become essentially zero. The expression essentially zero shall hereinafter be understood to mean that the tensile stress to which the compressed raw powder band is exposed while in the furnace has a value which allows the band which sintered freely to shrink or contract.
The invention is based on the recognition that the above purpose can only be achieved if, in addition to a friction-free support of the raw powder band through the sinter furnace, it is also ensured that the belt is not subjected to significant tensile load before it is introduced into the furnace. In other words, it is necessary first to minimize the tension in the belt at the furnace entry point and then to ensure that the belt transport is such that it does not counter the longitudinal shrinkage of the belt during sintering.
The method according to the invention is based on the above-mentioned technique, comprising continuous compression of powder to form a continuous raw powder band, continuous transport of the raw powder band to the inlet in a sinter furnace, operation of the band through the furnace by means of clamping rollers arranged downstream of the furnace, and supporting the belt of a gas pad during its transport through the furnace.
What distinguishes the invention from the prior art in accordance with the foregoing prior art is that the raw powder band, being introduced into the sinter furnace, is insulated from tensile stresses that the band is subjected to upstream by the sinter furnace; and that the tape is allowed to shrink linearly during sintering in the furnace by subtracting the sintered band from the furnace at a rate so much lower than the rate at which it is fed to the furnace that it corresponds to the linear reduction of the belt as it shrinks during passage in the furnace. oven.
As a result of this new and unique combination of features, the sintering process in the metal powder band can be carried out completely without the influence of interfering tensile forces, thus protecting against irregularities such as surface cracks in the finished sintered product.
The invention will now be explained in more detail with reference to the schematic drawing, in which:
Fig. 1 is a side view, partly in section, of a device for carrying out the method according to the invention.
FIG. 2 is a sectional view through the FIG. 1.
FIG. 2 is a side view of a belt rolling device manufactured by means of the one shown in FIG. 1.
FIG. 4 is a side elevational view of a device for reheating the rolled strip produced by the one shown in FIG. 3.
FIG. 5 is a side elevational view of a Sendzimir roll chair for rolling the tape produced by the one shown in FIG. 4, and
6 and 7 are side views, partly in section, of a further device for carrying out the method according to the invention.
The FIG. 1 and 2 comprises a funnel 1 containing powder P. The powder may be made of an ferrous material, e.g. ferritic or austenitic stainless steels, non-ferrous materials such as aluminum, a metal-containing ore or a metal oxide. Immediately below the funnel 1, two pressing rolls 2-2 are arranged in such a way that powder coming down through the open end of the funnel 1 is drawn into the roll slot or nipped between the rolls 2-2. As shown in FIG. 1, the rollers 2-2 are forcibly driven to rotate in opposite directions, and the entire assembly of rollers 2-2 and funnel 1 forms a press roll chair in which a raw powder band S. can be made.
After the press roll chair, two cooperating clamping rolls 4-4, a floating table 5, a sinter furnace 6, two cooperating pull-out clamping rollers 7-7 and a belt reeling device 8 are arranged in sequence. The rolled band is indicated by the reference number 9. The raw powder band S is fed as shown by the press roll chair. above the float table 5 and furnace 6 and is driven through the furnace by the clamping rollers 4-4 and 7-7. The rotational speeds of the feed clamp rolls 4-4 and the pull-out clamp rollers 7-7 are regulated relative to each other such that the tension obtained in the raw powder band as it passes through the sinter furnace 6 is substantially zero. For a raw powder band of austenitic stainless steel powder, the tensile stress will be adjusted to a value of less than 70,000 Pa (N / m), and for a ferritic powder to a value of less than 50,000 Pa. Therefore, in order to compensate for the shrinkage of the belt as it passes through the sinter furnace 6, the respective rotational speeds of the clamping rollers are synchronized by means of a control device 10, so that the rotational speed of the roller 7-7 is so much less than for the rollers 4-4 that the difference corresponds to the expected linear reduction of the belt as it shrinks during passage through the furnace.
The expected shrinkage can be determined by the knowledge of the composition of the raw powder band, the morphology of the metal powder and the conditions or conditions maintained in the sinter furnace. For a strip made of stainless steel powder, the linear reduction can go up to 5%. The linear reduction will usually be of the order of 1 to 2%. For a raw powder band made from materials such as metal oxides, the linear reduction can be as large as 30 to 40%. The setting of the control device 10 can be controlled automatically or manually in accordance with a quality control via feedback circuits. Alternatively, the tensile stress in the belt can be sensed on one or another<sub>6</sub> between the clamping rollers 4-4 and 7-7, and the thus-determined voltage is supplied to the regulating device 10 which acts as a differential control of the rotational speed of the clamping rollers. The tensile stress should preferably be sensed at some point inside the furnace ,,
The floating table 5 has a flat horizontal surface and is positioned to occupy as much as possible of the space between the clamping rollers 4-4 and the oven 6. The table 5 has a gas inlet 11 and many small gas outlets (not shown) in the upper surface, so that the raw powder band is supported on this before it is introduced into the oven.
In an alternative embodiment, the floating table is replaced with an air chamber with inclined side walls of similar type used in the furnace 6 and shown in FIG. 2.
In FIG. 1, it is clear that the sinter furnace 6 has a heat resistant liner and is provided with an inlet seal 13 and an outlet seal 14 arranged at the respective ends of the furnace. Along the underside of the furnace, a series of spaced gas inlet ports 15 are formed. These ports 15 may alternatively be formed along one or both sides of the furnace 6,
At least part of the gas content of the furnace 6 can be taken out through a conduit 19 and returned to the inlet ports 15 via the cooler 19A, the compressor 19B and a gas treatment chamber 19C in which contaminants such as e.g. oxygen, is removed. From a source 19D of the desired gas composition, additional gas is supplied to the recycled gas before being returned to the furnace. The recycled gas and the additional gas are heated to a predetermined temperature before the gas is re-introduced into the furnace 6.
Electric heating elements 16 are arranged inside the furnace 6 together with one or more heat control devices (not shown). Two horizontal tongues 17 are arranged along each of the vertical side walls inside the furnace. In an alternative embodiment, the tongues 17 may be inclined downwardly at a slight angle.
As the belt exits the sinter furnace 6, the belt is cooled and passed between the pull-out clamping rollers 7-7 and then rolled up in the belt reeling device 8 where a belt roll 9 is produced.
The roller 9 is then conveyed to a rolling station, as shown in FIG. 3. As shown, the belt is passed between the rollers 20 in a rolling chair 21 and then rewound into a belt reel 22, where a belt roll 23 is produced.
In an alternative arrangement, the strip is hot rolled before being cooled and rolled up. In this alternative arrangement, the hot rollers can replace the pull-out clamping rollers 7-7, and their rotational speed is regulated so that the tensile stress in the belt during the passage through the furnace is kept essentially at zero.
In FIG. 4, it is shown that after rewinding, the rollers 23 are unwound and passed through a rewarming station consisting of a furnace 24 and are re-wound again to produce a belt reel 25. The belt is fed to and from the furnace 24 by means of clamping rollers 26, respectively. extractor rollers 27. The furnace 24 may be identical to that shown in FIG. 1 and 2. In an alternative embodiment, the tape roll 25 is returned to the sinter furnace 6 where it is reheated. Alternatively, the furnace may be provided with a continuous running belt which supports the belt as it is transported through the furnace 24.
The tape roll 25 is finally conveyed to a final roll station shown in FIG. 5 in which the tape is rolled to the desired thickness in a sendzimir roll chair (Z-roll chair) 28 and then rewound to the finished tape roll 29.
During operation of the shown device or apparatus, steel powder P is drawn from the funnel 1 into the rolling gap between the pressing rolls 2-2 and comes from these as a raw powder band S. The strip is then passed by means of the clamping rollers 4-4 over the horizontal surface of the floating table. 5 and into the furnace 6 via the inlet seal 13 and out of the furnace via the outlet seal 14. The belt S is pulled from the furnace by means of the pull-out clamping rollers 7-7 and wound up by means of the belt reeling device 8.
When the belt is inside the furnace 6, it is supported by gas supplied under pressure through the gas inlet ports.
15. The contact between the edges of the tape and the tongue 17 arranged along the side walls of the furnace is reduced or hindered by the gas allowed to flow between the band edges and the inclined surfaces of the tongue 17, as shown by arrows 18. The gas flows out of the furnace through the conduit 19, is cooled, compressed and reheated before being returned to the furnace through the inlet ports 15<sub>c </sub>Gas lost through the inlet and outlet seals 13 and 14 is compensated by the addition of gas from the source 19D.
The gas supplied through the inlet ports 15 may comprise a mixture consisting of 20 volume percent hydrogen and 80 volume percent argon. The mixture may alternatively comprise a mixture of argon and a gas which chemically reacts with the strip, and to increase the nitrogen or carbon content of the metal powder from which the strip is made, the mixture may consist of argon and nitrogen respectively of argon and a hydrocarbon gas such as methane. To increase the nitrogen content by 0.2% in an austenitic stainless steel band, the gas mixture may consist of 25% nitrogen, 55% argon and 20% hydrogen.
For a belt made of stainless steel powder, the furnace temperature of about 1350 ° C is maintained by the heating elements 16, so that the belt S sintered at the correct temperature. The tensile stress applied to the belt while in the furnace 6 is kept mainly at zero due to the gas pad on which it is supported and because of the aforementioned synchronized rotational speed ratio between the clamping rollers 4-4 and 7-7.
The sintered belt is pulled out of the furnace by means of the pull-out clamping rollers 7-7 and the belt reeling device 8. The resulting roll 9 is then transported to the cold roll chair 21 in which the belt is rolled off, advanced between the rollers 20-20 and re-wound by means of the belt reeling device 22. Between the rollers 20-20 make a 20% reduction of the belt thickness.
The roller 23 is then conveyed to the one shown in FIG. 4, where the tape is unrolled, is passed through the furnace 24 by means of the clamping rollers 26-26 and 27-27 and then rewound to produce a roll 25.
Finally, the roller 25 is transported to the Z-roll chair 28 where the belt is rolled down to final thickness and rewound. The thickness reduction in the Z-roll chair is usually of the order of 35%, but can be significantly greater, depending on the desired thickness and finished product properties »
In a not shown embodiment, the sintered belt leaves the clamping rollers 7-7 and is transported directly to the roll chair 21 without any intermediate rolling-up step. The rolled strip coming from the rolling chair 21 can be added thereto or alternatively directly to the oven 24 without a winding step between the rolling line shown in FIG. 3 and the reheating line shown in FIG. 4.
The heating means in furnaces 6 and 24 need not be electric, but may e.g. be high frequency induction or electron beam devices.
Figure<sub>u</sub> 6 shows an alternative method of obtaining substantially zero tensile stress in the raw powder band S when it is transported through the sinter furnace 6 on the gas pad. In this alternative arrangement where the same reference numerals as in FIG. 1, a friction drum 30 is disposed between the press rolls 2-2 and the flow table 5.
The motor driven friction drum 30 is provided with an outer circumferential surface coating of friction material 31 which may be a suitable cellular elastomer such as e.g. polyurethane foam. In addition to the fact that this material provides frictional engagement between its surface and the raw powder band passed over this surface, it is resistant to powder retained on the surface. Loose powder that accumulates on the surface of cellular material 31 as the band passes over the surface will be introduced into the open pores of this material and will be removed therefrom by gravity as the drum 30 rotates and clears the raw powder band.
In operation, the raw powder band S coming from the press roll chair is fed over a portion of the outer circumferential surface of the material 31 of the friction drum 30, over the floating table 5, through the furnace 6 and between two counter-rotating outlet rollers 32-32 to the reeling device 8 »As in the arrangement of FIG. 1, the raw powder band is supported by a gas pad with gas supplied through inlet ports 15 while the band is in the furnace 6.
As previously mentioned, it is essential that the tensile stress that occurs in the raw powder band S is kept substantially equal to zero. In the embodiment of FIG. 6, the crude powder belt hangs down in a small arcuate loop L between the press roll chair and the friction drum 30, but the rotational speed of the friction drum 30 is such that with respect to the rotational speed of the press rolls 2-2, the outlet rollers 32-32 and the roll-up device are kept in the main tension band tension. zero. The tensile stress will also be substantially zero from the friction drum 30 onwards during the passage of the belt over the floating table 5 and through the furnace 6.
In use, the friction drum 30 is operated such that the circumferential surface velocity is slightly greater than the velocity of the raw powder band when coming from the press rolls 2-2. The retention voltage obtained in the belt as it enters the furnace 6 can be adjusted to the desired zero level by adjusting the height of the suspension for the loop L. This control is obtained by adjusting or adjusting the rotational speed of the pull-out rollers 32-32 and the reeling device 8 after the outlet end of the furnace 6. This speed control can be performed automatically depending
sensing devices such as e.g. may indicate the tension in the belt at a location below its passage across the floating table 5.
Fig. 7 shows yet another device for obtaining substantially zero tensile stress in the raw powder band S as it is transported through the sinter furnace 6. In this alternative arrangement, a curved, downward sloping flow table 35 is arranged between the press rolls 2-2 and the inlet port 41 of the furnace 6. Gas is supplied. the float table 35 through a conduit 36. The furnace 6 is inclined at a slight angle to the horizontal to allow the belt to flow through the furnace under the influence of gravity. The angle of inclination is such with respect to the horizontal that the frictional forces on the belt as it passes through the furnace 6 are balanced by the gravity acting on the belt, the angle may be of the order of 0.5 to 5 ° and can be arranged by placing the inlet port 41 in the furnace on a somewhat higher than the outlet port 42 = A sensing device determines the distance between the table 35 and the band S „
The belt is driven through the furnace by means of two counter-rotating outlet rollers 37, and the rotational speed of these rollers is controlled via a controller 40 to maintain substantially zero tensile stress in the belt on the basis of signals from the sensing device 39 indicating the tension in the belt S. The retention voltage in this belt can way is maintained at the desired value □
Although the invention has been described with reference to the production of metal strips from a raw powder band produced by passing metal powder through a press roll chair, it is easy to understand that other methods can be used to produce a raw powder band from a powdered starting material. Such a method may comprise depositing on a support surface a slurry consisting of a suspension of a powdered material in a binder composition, drying the slurry on the support surface to form a self-supporting film, removing the dried film from the support surface, and that the dried film is compressed by rolling to form a crude powder band.
5 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5
44 members in 31 offices
Priority claims8
| Document | Office | Kind | Date |
|---|---|---|---|
| 2110373 | United Kingdom | A | |
| 2110373 | United Kingdom | A | |
| 450074 | United Kingdom | A | |
| 450074 | United Kingdom | A | |
| 2110373 | – | – | – |
| 450074 | – | – | – |
| GB19730021103 | – | – | – |
| GB19740004500 | – | – | – |
Members44
| Document | Office | Kind | |
|---|---|---|---|
| IL44686A0 | Israel | A0 | |
| IL44686D0 | Israel | D0 | |
| LU69978A1 | Luxembourg | A1 | |
| BE814485A | Belgium | A | |
| IE39215L | Ireland | L | |
| NL7405951A | Netherlands (Kingdom of the) | A | |
| NO741581L | Norway | L | |
| DE2421318A1 | Germany | A1 | |
| FR2227919A1 | France | A1 | |
| BR7403563D0 | Brazil | D0 | |
| AR201229Q | Argentina | Q | |
| DD112087A5 | German Democratic Republic (until 1990) | A5 | |
| JPS5041705A | Japan | A | |
| ZA742485B | South Africa | B | |
| AU6855074A | Australia | A | |
| AT334718B | Austria | B | |
| ATA363874A | Austria | A | |
| ES425787A1 | Spain | A1 | |
| TR17995A | Türkiye | A | |
| IN140501B | India | B | |
| CH584082A5 | Switzerland | A5 | |
| PL90394B1 | Poland | B1 | |
| GB1466364A | United Kingdom | A | |
| FR2227919B1 | France | B1 | |
| CA1013180A | Canada | A | |
| IL44686A | Israel | A | |
| US4042384A | United States of America | A | |
| SE399372B | Sweden | B | |
| IE39215B1 | Ireland | B1 | |
| NO140288BThis record | Norway | B | |
| HU173424B | Hungary | B | |
| NO140288C | Norway | C | |
| KR790001990B1 | Republic of Korea | B1 | |
| FI58082B | Finland | B | |
| FI58082C | Finland | C | |
| DE2421318B2 | Germany | B2 | |
| JPS5624683B2 | Japan | B2 | |
| DE2421318C3 | Germany | C3 | |
| IT1055570B | Italy | B | |
| RO66625A | Romania | A | |
| YU117274A | Yugoslavia, later Serbia and Montenegro (until 2006) | A | |
| CS216904B2 | Czechoslovakia (until 1993) | B2 | |
| YU36632B | Yugoslavia, later Serbia and Montenegro (until 2006) | B | |
| NL178757C | Netherlands (Kingdom of the) | C |
Numbers
- Publication
- 140288
- Publication, DOCDB
- 140288
- Publication, EPODOC
- NO140288B
- Application
- 741581
- Application, DOCDB
- 741581
- Application, EPODOC
- NO19740001581
Titles2
- Norwegian
- FREMGANGSMAATE FOR KONTINUERLIG FREMSTILLING AV METALLBAAND, -STRIMLER O.L. AV ET PULVERMATERIALE
- English
- PROCEDURE FOR CONTINUOUS PREPARATION OF METAL BANDS, STRIPS OF A POWDER MATERIAL
Classification
- CPC, 4
- B22F5/006
- B22F3/18
- B22F2999/00
- C21D9/63
- IPC, 4
- B22F3 18
- B22F3 10
- B22F5 00
- C21D9 63
