DK152691B - PROCEDURE FOR THE MANUFACTURE OF IRON CONCRETE - Google Patents
PROCEDURE FOR THE MANUFACTURE OF IRON CONCRETE Download PDFInfo
- Publication number
- DK152691B DK152691B DK455481A DK455481A DK152691B DK 152691 B DK152691 B DK 152691B DK 455481 A DK455481 A DK 455481A DK 455481 A DK455481 A DK 455481A DK 152691 B DK152691 B DK 152691B
- Authority
- DK
- Denmark
- Prior art keywords
- cooling
- limit
- iron
- mpa
- manufacture
- Prior art date
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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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
-
- 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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/08—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires for concrete reinforcement
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- 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
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Heat Treatment Of Steel (AREA)
- Metal Rolling (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
- Reinforcement Elements For Buildings (AREA)
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
Description
DK 152691 BDK 152691 B
Den foreliggende opfindelse angår en fremgangsmåde ved økonomisk fremstilling af armeringsjern til beton, hvilke jern udmærker sig ved en høj elasticitetsgrænse og strækbarhed, samtidig med om ønsket en god svejsbarhed, idet fabrikationen 5 gennemføres ved en behandling i form af en hurtig nedkøling udført under eller umiddelbart efter udvalsningen.The present invention relates to a method of economically producing reinforcing iron for concrete, which is characterized by a high elasticity limit and extensibility, while at the same time a good weldability, the fabrication 5 being carried out by a treatment in the form of a rapid cooling performed under or immediately after the roll-out.
Det er kendt, at man ved udvalsningen, hvis man vil løse de stillede problemer, må tage stilling til en række hindringer. For det første ligger ved udvalsningen i praksis hastig-10 heden og udgangstemperat viren for jernene fast og for øvrigt er der kun en begrænset plads til installation af eventuelle afkølingsapparater.It is well known that in order to solve the problems posed, a number of obstacles must be considered in the selection process. Firstly, in practice, the speed and output temperature of the wire for the iron are fixed at the milling and, moreover, there is only a limited space for installation of any cooling apparatus.
Der eksisterer allerede forskellige løsninger til at komme frem til et kompromis mellem de mekaniske egenskaber på 15 den ene side og fabrikationsprisen på den anden side.Various solutions already exist to arrive at a compromise between the mechanical properties on the one hand and the fabrication price on the other.
En første løsning består i at fremstille armeringsjernene med en naturlig hårdhed, hvorved den ønskede elasticitetsgrænse opnås ved tilførsel af kulstof (f.eks. 0,35%) og mangan (f.eks. 1,3%), hvorved sådanne stålsorter frembyder en 20 acceptabel elasticitetsgrænse (=420 MPa), men forlængelsen og egnetheden ved bøjning er relativt ringe og svejsbarheden klart utilstrækkelig.A first solution consists of producing the reinforcing bars with a natural hardness, whereby the desired elasticity limit is obtained by supplying carbon (e.g. 0.35%) and manganese (e.g. 1.3%), thereby providing such steel grades. 20 acceptable limit of elasticity (= 420 MPa), but the elongation and suitability of bending is relatively poor and the weldability is clearly inadequate.
For at forbedre svejsbarheden er det nødvendigt at formindske indholdet af kulstof, hvilket medfører en nedsættelse 25 af elasticitetsgrænsen.To improve weldability, it is necessary to reduce the carbon content, which results in a reduction of the elastic limit.
For at kompensere for denne nedsættelse af elasticitetsgrænsen eksisterer der to kendte midler.To compensate for this reduction of the elastic limit, two known means exist.
Det første består i i jernet at inkorporere mikrolegeringer, såsom niobium eller vanadium. Denne teknik er imidler-30 tid kostbar på grund af legeringselementerne.The first is to incorporate in the iron microalloys such as niobium or vanadium. However, this technique is expensive because of the alloying elements.
En anden måde til forøgelse af elasticitetsgrænsen for stålet er en kolddeformationsoperation, specielt ved torsion af armeringsjernet. Ud over de omkostninger, som en sådan operation ligeledes medfører, er gevinsten i forhøjelse af ela-35 sticitetsgrænsen sket på bekostning af forlængelsen.Another way to increase the elastic limit of the steel is a cold deformation operation, especially by torsion of the reinforcing iron. In addition to the costs that such an operation also entails, the gain in increasing the elasticity limit has been at the expense of the extension.
Fremgangsmåden ifølge den foreliggende opfindelse skal henføres til den teknik, der består i at påføre betonjernene 2The method of the present invention is to be attributed to the technique of applying the cast iron 2
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i varm tilstand under eller umiddelbart efter udvalsningen en hurtig afkøling, som er tidsbegrænset på en sådan måde, at der i stangens overfladelag dannes martensit eller bainit, idet denne hærdning er efterfulgt af en afkøling, under hvilken 5 kernen af stangen, dvs. den del, som ikke er underkastet den hurtige afkøling, transformeres til ferrit og kulstofforbindelser. Ved en forstandig begrænsning af den hurtige afkølings varighed er det endvidere muligt at bevare varmen i stangens midte og i denne del at frembringe en temperaturgradient, som 10 linder den .videre afkøling bevirker en anløbning af overfladelaget af martensit og bennit. En sådan skønsom begrænsning i varigheden af den hurtige nedkøling kan sikres ved at sigte mod.„en fastlagt temperatur i midten ved slutningen af den hurtige afkøling; i praksis kan man udføre en sådan operation ved 15 at observere overfladetemperaturen på stangen eller man konstaterer en genopvarmning, som har fundet sted på grund af kalorier, som kommer fra kernen.in hot state during or immediately after rolling out, a rapid cooling which is time-limited in such a way that martensite or bainite is formed in the surface layer of the rod, this curing being followed by a cooling, during which the core of the rod, ie. the part which is not subject to rapid cooling is transformed into ferrite and carbon compounds. Furthermore, by sensibly limiting the duration of the rapid cooling, it is possible to retain the heat in the center of the bar and to produce in this part a temperature gradient which alleviates the further cooling causing an annealing of the surface layer of martensite and bennite. Such a discretionary limitation in the duration of the rapid cooling can be ensured by aiming for: "a fixed temperature in the middle at the end of the rapid cooling; In practice, such an operation can be performed by observing the surface temperature of the rod or a reheating which has occurred due to calories coming from the core.
En sådan fremgangsmåde betegnes almindeligvis som hærdning og selvanløbning og kan altså iværksættes i en bestemt 20 installation med kendte specifikationer til fremstilling af veldefinerede armeringsjern ud fra karakteristiske egenskaber som består i temperaturen i kernen ved afslutningen af den bratte afkølingsfase, idet det iøvrigt er nødvendigt at denne temperatur skal være omkring 850°C for at opnå en optimal kom-25 bination af høj elasticitetsgrænse og forlængelse på armeringsjernet.Such a process is generally referred to as curing and self-soaking and can thus be initiated in a particular installation with known specifications for producing well-defined reinforcing iron from characteristic properties which exist in the core temperature at the end of the steep cooling phase, otherwise it is necessary to temperature must be around 850 ° C to achieve an optimal combination of high elasticity limit and elongation on the reinforcing iron.
Den praktiske gennemførelse af denne kombination medfører klart en fabrikation af armeringer med forbedret kvalitet, men for at opnå denne kondition må fagmanden selv vælge midler-30 ne for at opnå den tilsigtede temperatur.The practical implementation of this combination clearly results in the fabrication of reinforcements of improved quality, but in order to achieve this condition, the person skilled in the art must select the means to achieve the desired temperature.
Fremgangsmåden ifølge den foreliggende opfindelse tager sigte på at præcisere for hver type produkt de parametre, som karakteriserer en anvendelse af den bratte afkøling takket være hvilken armeringsstålene opnår de planlagte egenskaber.The method of the present invention aims to specify for each type of product the parameters which characterize an application of the steep cooling thanks to which the reinforcing steel achieves the planned properties.
35 Man ved, at disse parametre på den ene side er intensiteten af den bratte afkøling, dvs. middeltætheden af varmestrømmen mellem 800°C og 600°C almindeligvis betegnet med φ og udtrykt i 235 On the one hand, these parameters are known to be the intensity of the steep cooling, ie. the mean density of the heat flow between 800 ° C and 600 ° C is usually denoted by φ and expressed in 2
DK 152691 BDK 152691 B
3 MW/m og på den anden side varigheden af den bratte afkøling betegnet med t og udtrykt i sekunder.3 MW / m and on the other hand the duration of the steep cooling denoted by t and expressed in seconds.
Denne fremgangsmåde er især anvendelig ved fabrikation af armeringsstål med mekaniske egenskaber svarende til en kva-5 litetsnorm/ f.eks. en elasticitetsgrænse mellem 400 og 600 MPa og en forlængelse i det mindste lig med 14%.This method is particularly useful in the fabrication of reinforcing steel with mechanical properties corresponding to a quality standard / e.g. a limit of elasticity between 400 and 600 MPa and an elongation at least equal to 14%.
Fremgangsmåden til fremstilling af armeringsjern i henhold til den foreliggende opfindelse, ved hvilken den bratte afkøling af jernene finder sted umiddelbart efter valsningen, 10 er i det væsentlige karakteriseret ved, at parametrene φ og t til regulering af den bratte afkøling samtidig overholder følgende formler: 0,45 d - 0,4 > < 0,82 d. + 0,6 logφ= - 0,964 . log d +2,098 15 i hvilke d repræsenterer diameteren af den behandlede stang udtrykt i mm.The method of producing reinforcing iron according to the present invention, in which the steep cooling of the iron takes place immediately after rolling, 10 is substantially characterized in that the parameters φ and t for controlling the steep cooling simultaneously comply with the following formulas: 0 , 45 d - 0.4> <0.82 d. + 0.6 logφ = - 0.964. log d +2,098 15 in which d represents the diameter of the treated rod expressed in mm.
Fremgangsmåden udøves ved at man først bestemmer den minimums varmestrømstæthed (φ), som vil fremkalde den nødvendige kølingsintensitet under hærdeprocessen afhængigt af stang-20 diameteren (d). Denne minimumsværdi fremkommer ved hjælp af den anden formel (log φ). På den anden side giver den første formel en nedre værdi og en øvre værdi for produktet (φ . t), hvilket fører til elasticitetsgrænser på henholdsvis 400 MPa og 600 MPa. Eftersom elasticitetsgrænsen varierer lineært mel-25 lem disse to værdier, kan den nødvendige værdi af produktet (φ · t) og dermed tiden (t) bestemmes ud fra den tilsigtede værdi af elasticitetsgrænsen. Anvendelsen af en bestemt køleintensitet gennem et bestemt tidsrum, hvor køleintensiteten og tidsrummet bestemmes som anført ovenfor, fører til frem-30 stilling af armeringsjern med den ønskede elasticitetsgrænse.The process is performed by first determining the minimum heat flux density (φ) which will produce the necessary cooling intensity during the curing process depending on the bar diameter (d). This minimum value is obtained by the second formula (log φ). On the other hand, the first formula gives a lower value and an upper value for the product (φ. T), leading to elastic limits of 400 MPa and 600 MPa respectively. Since the elastic limit varies linearly between these two values, the required value of the product (φ · t) and thus the time (t) can be determined from the intended value of the elastic limit. The use of a particular cooling intensity over a certain period of time, in which the cooling intensity and the time period is determined as stated above, leads to the production of reinforcing bars of the desired elasticity limit.
Fremgangsmåden ifølge opfindelsen gør det muligt at opnå yderst interessante produkter, hvad angår kombinationen af mekaniske egenskaber, dvs. for det første at størrelsen af zo-35 nen indeholdende martensit/bainit såvel som dens grad af blødgør ing ved selvanløbning er sådan, at der opnås en høj elasti- 4The process according to the invention makes it possible to obtain extremely interesting products in terms of the combination of mechanical properties, ie. first, that the size of the zone containing martensite / bainite as well as its degree of softening by self-flow is such that a high elasticity is obtained.
DK 152691 BDK 152691 B
citetsgrænse dels en forlængelse, der altid er i det eftersøgte område.quotation limit and an extension that is always in the requested area.
Et første eksempel på udøvelse af fremgangsmåden ifølge opfindelsen angår fabrikationen af stænger med en diameter 5 på 20 mm, som forlader valseværket med en hastighed på 12 m per sekund og en temperatur på 1050°C. Af hensyn til svejsbarhed og økonomi er den kemiske sammensætning af stålet indeholdt i et bestemt interval, f.eks. 0,10 - 0,20% C, 0,8 - 1,3% Mn.A first example of the practice of the invention relates to the fabrication of rods with a diameter of 20 mm which leave the rolling mill at a speed of 12 m per second and a temperature of 1050 ° C. For the sake of weldability and economy, the chemical composition of the steel is contained within a certain range, e.g. 0.10 - 0.20% C, 0.8 - 1.3% Mn.
I det foreliggende tilfælde er indholdet 0,13% C og 1,2% Mn, 10 hvilket i rå tilstand fra udvalsningen ville frembyde en elasticitetsgrænse omkring 365 MPa og en forlængelse på 22-24%.In the present case, the content is 0.13% C and 1.2% Mn, which in the crude state from the roll-out would present an elastic limit of about 365 MPa and an extension of 22-24%.
For at frembringe armeringsjern med forbedret elasticitetsgrænse og strækbarhed vælger valseværksarbejderen ud fra de materielle og pladsmæssige forhold en installation, hvor 15 intensiteten af den bratte afkøling og længden af zonen, hvori den finder sted (altså varigheden af behandlingen) svarende til de nævnte betingelser, som er: φ £ 7 MW/m^ 8,6 > φ-t > 17 20 Valget af en installation, hvor middelt æt heden af varme- strømmen mellem 800 og 600°C er 10 MW/ια og længden af zonen 12 m, medfører en elasticitetsgrænse på 500 MPa og en forlængelse på 20,6%; valget af en installation, der er karakteriseret 2In order to produce reinforcing iron with improved elasticity limit and extensibility, the rolling mill worker selects from the material and spatial conditions an installation in which the intensity of the steep cooling and the length of the zone in which it takes place (ie the duration of the treatment) according to the conditions mentioned, such as is: φ £ 7 MW / m ^ 8.6> φ-t> 17 20 The choice of an installation where the average heat of the heat flow between 800 and 600 ° C is 10 MW / ια and the length of the zone 12 m, results in a limit of elasticity of 500 MPa and an extension of 20.6%; the choice of an installation characterized 2
ved φ =8,4 MW/m og længden 20,5 m giver et betonstål med en 25 elasticitetsgrænse på 550 MPa og en forlængelse på 18,5%. Iat φ = 8.4 MW / m and the length 20.5 m gives a concrete steel with a 25 MPa limit of elasticity and an extension of 18.5%. IN
dette tilfælde har varigheden været 1,7 sekunder og produktet φ .t = 14,35.in this case the duration has been 1.7 seconds and the product φ .t = 14.35.
Et andet eksempel angår fabrikation af stænger med en diameter på 8 mm, som forlader valseværket med en hastighed 30 på 18 m/sek. og en temperatur omkring 1000°C. Stålet indeholder 0,18% C og 0,8% Mn og i rå tilstand fra valsningen har det en elasticitetsgrænse på 325 MPa og en forlængelse af størrelsesordenen 30%.Another example concerns the fabrication of bars with a diameter of 8 mm leaving the mill at a speed of 30 m / sec. and a temperature of about 1000 ° C. The steel contains 0.18% C and 0.8% Mn and in the raw state from the rolling it has a limit of elasticity of 325 MPa and an extension of the order of 30%.
I dette tilfælde er grænserne som fremgangsmåden ifølge 35 opfindelsen medfører: 5In this case, the limits which the method of the invention entails: 5
DK 152691 BDK 152691 B
Φ = 17 MW/m2 3,2 < <j>.t< 7/16Φ = 17 MW / m2 3.2 <<j> .t <7/16
Hvis man vælger en installation/ som sikrer en φ = 17 MW/m2 med en længde af behandlingszonen på L = 4,5 m opnår man stæn- 5 ger med en elasticitetsgraense på 500 MPa og en forlængelse på 18%. I dette tilfælde er varigheden af behandlingen 0/25 sek.If you choose an installation / that ensures a φ = 17 MW / m2 with a length of the treatment zone of L = 4.5 m, you close 5 with an elastic limit of 500 MPa and an extension of 18%. In this case, the duration of treatment is 0/25 sec.
og produktet φ.t udgør 4,25. Man opnår samme egenskaber ved 2 φ = 35 MW/m og en behandlingsvarighed på 0,17 sek., hvilket svarer til en længde af den bratte afkølingszone på 3 m.and the product φ.t is 4.25. The same properties are obtained at 2 φ = 35 MW / m and a treatment duration of 0.17 sec, which corresponds to a length of the steep cooling zone of 3 m.
Claims (1)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE6/47492A BE889575A (en) | 1981-07-09 | 1981-07-09 | PROCESS FOR THE MANUFACTURE OF STEEL CONCRETE REINFORCEMENTS WITH IMPROVED PROPERTIES. |
| BE6047492 | 1981-07-09 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| DK455481A DK455481A (en) | 1983-01-10 |
| DK152691B true DK152691B (en) | 1988-04-18 |
| DK152691C DK152691C (en) | 1988-08-29 |
Family
ID=3874897
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DK455481A DK152691C (en) | 1981-07-09 | 1981-10-14 | PROCEDURE FOR THE MANUFACTURE OF IRON CONCRETE |
Country Status (21)
| Country | Link |
|---|---|
| JP (1) | JPS589920A (en) |
| KR (1) | KR870001090B1 (en) |
| AT (1) | AT375401B (en) |
| AU (1) | AU536703B2 (en) |
| BE (1) | BE889575A (en) |
| BR (1) | BR8108179A (en) |
| CA (1) | CA1201960A (en) |
| CH (1) | CH639137A5 (en) |
| DD (1) | DD202309A5 (en) |
| DK (1) | DK152691C (en) |
| ES (1) | ES513811A0 (en) |
| FI (1) | FI72748C (en) |
| GR (1) | GR77249B (en) |
| IE (1) | IE53019B1 (en) |
| IN (1) | IN154221B (en) |
| LU (1) | LU84263A1 (en) |
| MX (1) | MX159859A (en) |
| NO (1) | NO156903C (en) |
| SE (1) | SE462853B (en) |
| YU (1) | YU42779B (en) |
| ZA (1) | ZA818244B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6066099A (en) * | 1983-09-21 | 1985-04-16 | Hitachi Ltd | Temperature balance control of multistage heat exchanger |
| CH681603A5 (en) * | 1984-05-30 | 1993-04-30 | Von Roll Ag | |
| JPS61110897A (en) * | 1984-11-06 | 1986-05-29 | Toshiba Corp | Flow rate control method of heat exchanger |
| DD234281B1 (en) * | 1984-12-21 | 1989-06-21 | Florin Stahl Walzwerk | METHOD FOR PRESSURE WATER TREATMENT OF ROLLING STEEL PRODUCTS |
| KR101225251B1 (en) * | 2010-09-29 | 2013-01-22 | 현대제철 주식회사 | Apparatus for manufacturing high-strength steel bars in adjusting metallugical transformation and the method thereof |
| RU2583554C1 (en) * | 2015-01-22 | 2016-05-10 | Акционерное общество "Научно-исследовательский центр "Строительство" (АО "НИЦ "Строительство") | Method for production of hardened reinforcing bar of periodic profile |
-
1981
- 1981-07-09 BE BE6/47492A patent/BE889575A/en not_active IP Right Cessation
- 1981-08-21 IN IN934/CAL/81A patent/IN154221B/en unknown
- 1981-08-31 CH CH559081A patent/CH639137A5/en not_active IP Right Cessation
- 1981-10-14 DK DK455481A patent/DK152691C/en active
- 1981-11-13 JP JP56182941A patent/JPS589920A/en active Granted
- 1981-11-27 ZA ZA818244A patent/ZA818244B/en unknown
- 1981-12-16 BR BR8108179A patent/BR8108179A/en unknown
- 1981-12-18 AU AU78624/81A patent/AU536703B2/en not_active Ceased
-
1982
- 1982-07-07 SE SE8204207A patent/SE462853B/en not_active IP Right Cessation
- 1982-07-07 GR GR68675A patent/GR77249B/el unknown
- 1982-07-08 YU YU1497/82A patent/YU42779B/en unknown
- 1982-07-08 NO NO822384A patent/NO156903C/en unknown
- 1982-07-08 LU LU84263A patent/LU84263A1/en unknown
- 1982-07-08 CA CA000406914A patent/CA1201960A/en not_active Expired
- 1982-07-08 IE IE1651/82A patent/IE53019B1/en not_active IP Right Cessation
- 1982-07-08 AT AT0265382A patent/AT375401B/en not_active IP Right Cessation
- 1982-07-08 FI FI822426A patent/FI72748C/en not_active IP Right Cessation
- 1982-07-08 ES ES513811A patent/ES513811A0/en active Granted
- 1982-07-09 DD DD82241555A patent/DD202309A5/en not_active IP Right Cessation
- 1982-07-09 MX MX193521A patent/MX159859A/en unknown
- 1982-07-09 KR KR8203079A patent/KR870001090B1/en active
Also Published As
| Publication number | Publication date |
|---|---|
| GR77249B (en) | 1984-09-11 |
| CH639137A5 (en) | 1983-10-31 |
| DK152691C (en) | 1988-08-29 |
| BR8108179A (en) | 1983-04-12 |
| SE462853B (en) | 1990-09-10 |
| CA1201960A (en) | 1986-03-18 |
| DK455481A (en) | 1983-01-10 |
| IE821651L (en) | 1983-01-09 |
| FI822426L (en) | 1983-01-10 |
| NO822384L (en) | 1983-01-10 |
| BE889575A (en) | 1982-01-11 |
| ZA818244B (en) | 1983-04-27 |
| MX159859A (en) | 1989-09-21 |
| ES8401530A1 (en) | 1983-12-01 |
| IE53019B1 (en) | 1988-05-11 |
| KR840000653A (en) | 1984-02-25 |
| AU536703B2 (en) | 1984-05-17 |
| YU42779B (en) | 1988-12-31 |
| NO156903B (en) | 1987-09-07 |
| SE8204207D0 (en) | 1982-07-07 |
| ES513811A0 (en) | 1983-12-01 |
| IN154221B (en) | 1984-10-06 |
| LU84263A1 (en) | 1983-02-07 |
| AT375401B (en) | 1984-08-10 |
| KR870001090B1 (en) | 1987-06-04 |
| NO156903C (en) | 1987-12-16 |
| FI72748B (en) | 1987-03-31 |
| ATA265382A (en) | 1983-12-15 |
| JPS6219488B2 (en) | 1987-04-28 |
| FI822426A0 (en) | 1982-07-08 |
| AU7862481A (en) | 1983-01-13 |
| JPS589920A (en) | 1983-01-20 |
| YU149782A (en) | 1985-04-30 |
| FI72748C (en) | 1987-07-10 |
| DD202309A5 (en) | 1983-09-07 |
| SE8204207L (en) | 1983-01-10 |
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