DE1627640A1 - Process for skin-passaging a long product made of carbon steel, in particular for use in prestressed concrete, and products obtained by this process - Google Patents

Description

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Applicant: i'refileries et Cableries de Bourg et du Havre, Bourg-en Bresse (Mn), i? 'Ram: rich

Method for skin-passaging an elongated product Made of carbon steel, in particular for use for Prestressed concrete and products obtained by this process.

The invention relates to a method for dressing a Product of elongated shape made of carbon steel, in particular for use in prestressed concrete, and obtained by this process Products.

The invention is based on the object of such. To give steel products improved mechanical properties, in particular an increased breaking strength and an increased In addition, they should have a predetermined strength Maintaining pretension in high ka, i.e., relaxation oppose an increased resistance.

In the present application, products of elongated shape are understood to mean products made of carbon steel, such as, for example Wires, rods, rods or connections of wires, like cables or strands.

The following description relates specifically to wires, but the invention also applies to all elongate products made of steel applicable.

The one generally used for wires for such applications The steel used generally includes:

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-Si-

Ο, όϋ to O ₁ JO; ό -Ioiilenscoff, 0.30 to 1.25 ;> Manganese, 0.10 to 0.40 i'o oiliciuia and otherwise iron and the usual industrial steels.

For wires that are to be used as reinforcement in Spannbecon or uls ij'edern, you want i :; _t general the following mechanical properties:

sufficient straightness, high breaking strength, high tensile strength, high elongation and little relaxation.

. Usually such steel wires are made by that it was first patented (austenization bsi 850/950 ° C and subsequent rapid cooling to 450/500 ° C) - and then through several drawing nozzles, which the cross-section of the wire decrease.

Wires obtained in this way are unsatisfactory because, if they have a high breaking strength, their tensile strength and elongation are too low, and if they need to increase their tensile strength and elongation, they are subjected to a desiccation, usually in the case of iiauint eraper at ur, with the disadvantage that the breaking strength is reduced .

From your British Patent 74 ^ 357 (Soiaerset) a method is begannt, to train cold drawn wires, one ^for the wire, after having heated it to 220 C to 520 C and preferably 25Ο ⁰ C to 310 C, sufficiently strongly in Longitudinal pulls to stretch it permanently while doing the

009886/0055

x'a..osratAr is held.

these..; Method i-auii uan steel wires with medium-sized eggs! ^ .- vertja i.ühlens * «ofi" _£ ieLalt obtained, which have a high tension! 3SU ~; t.-sit ; ni coagulated relaxation, that is, under tension their op ' Ianaru-Dex hold, whereby the resistance to stretching is very close to the any-, i; e of the üruch resistance.

The Srfxndaag concerns a method for skin-passaging. . ■ eip.es luiurlxotien product from l- * onlen3toffsfcahl _f especially for / ürweiiia: i _t : xn dpaniibeton, iuit high mechanical strength, lAui.er dtrecnfestigiteit, high deiuiung and high u n'i / d first and _{fore f} -en! .iitvoltage. This procedure has the following 7-step steps

1.) a ΛΗβ ^ αηββκ ^ ΐβΓΧθΙ made of steel elongated foria • »vir ··! patented,

t ..) the ab.uessungea of the 'cross-section of this material v / earth ver.ain.dert by cold working,

3.) the resulting material is trained.

This method is eriindangs ^ eicais characterized net that the temper rolling is effected by alternately bending in different radial planes at a temperature above ambient temperature and below the Umkristallisationsteuperatur of the steel of the d§m temper rolling subject product, and that the leingliche product is then cooled back to ambient temperature .

The skin pass through alternating bends is preferably carried out at a temperature above eiQO C.

The present invention thus differs from the method described in said British patent specification in that the wire is at a temperature between ambient temperature and the Uab.ri st alii sat ions- t- -

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temperature is trained by alternating bending, instead of it being pulled sufficiently in the longitudinal direction to make it one to communicate permanent stretching.

In addition, you have to pull the wire according to your invention Patent the process before permanently deforming it by cold working and then alternately bending it trained.

Passing wires by alternately bending them at ambient temperature is a well-known technique for making steel wires to train. This procedure consists in moving the wire one after the other by decreasing amounts in alternating liichten to bend in planes which are opposite to the axis of the Wire are oriented radially differently.

This temper rolling by alternately bending .ANN, for example, be carried out by that is allowed to pass through the wire between two sets of rollers, .which in two relative to the axis of the wire senicrecht-eu layer * ¹ are arranged, or even by "Len Lets wire pass through latrices which are axially displaced with respect to the axis of the running wire and are positively connected to a rotating frame.

Amazingly, it has been shown that the mechanical Properties of the wire in accordance with the invention are essential are better than the mechanical properties of the same wire when it is trained according to British patent / 48 357 is.

The invention also relates to elongated steel products, obtained by said process, these products being increased by increased mechanical strength Characterized by tensile strength, better elongation and improved resistance to relaxation.

009886 / 005S BAP ° ^nGS

To better explain the invention with reference to the single .Figur of the accompanying drawings described advantageous embodiment.

In this drawing, there is a device shown for performing the method according to the invention.

This device does not include the patenting of the Wire required device nor the device to the Wire by cold deformation i the required permanent deformation to g-even before turning it into the one shown in the drawing "Introduces device.

This device has a set of iron rollers 2, between which the wire 1 is inserted after the patenting and cold forming. The wire 1 then runs through its heating device, which consists, for example, of a self- induction heating device 3.

The desired in this way to the temperature did lies according to the invention below the recrystallised i onstemperatur of the steel, placed in wire then passes through the sets of temper rolling 4 and 5, which are arranged in two Ibanen, which together form an angle of 90 °. These rollers pass the wire through alternating bends.

The wire 1 then passes through a cooling device 6 and is finally wound onto a reel 7, the diameter of which is sufficiently large that the wire does not suffer permanent deformation.

According to a particular embodiment of the invention , it is based on a conventional wire that! a steel of the following composition beatehti

BATH

009886/0056

0.80 ', Ό carbon,

0, / 0 yes I / Iagnesium,

0.20 fo silicon,

0.06 · / » sulfur and phosphorus.

The heat consists of iron and the conventional ones Impurities in industrial steels.

This wire with a diameter of 11 μm is initially used Patented in a conventional way and then its diameter is reduced to 7 mia by cold drawing.

The wire thus obtained has the following mechanical Properties on;

2
Breaking strength: 173 kg / mm _f

Streak resistance at 0.112 kg / mm, elongation at break to a length of 500 mmt 2.5 i ».

The wire obtained in this way is then alternately Bending at ambient temperature adjusted, according to the well-known Process and its mechanical properties are changed as follows:

2
Breaking strength: 172 kg / nm,

Streekfeatigkeit at 0.1 $: 108 kg / mm _r elongation at break to a length of 500 mni: 3.2 $ ..

Furthermore, according to the conventional method, the so dressed wire at 280 ° C

In the two following tables, the left column shows the properties of the wire treated in the manner described, and the right column shows the mechanical properties of the wire treated according to the invention, ie the wire which, after reduction, is

.BATH"

009886/0061

esters d ircL draw Bxf , - im :, directly treated by alternating oei -ri.ier temperature voii L? -0 C v / urde.

Table 1

ec ^ f
J, I ca ti «;.
but 500 "a at
and D r e s i eren ·· at 2cü ° C Ui.vjeba
reason ng
en ste.; iperature
at 23ü G 133 2
ifci '/ Iiii.l j / Λ - ' j * / ιλ. 2 4, ng / mm 3rd r
at 4.03 / u

labile

at
and Passage at 280 ° C Ambient temperature
Tempering at 260 ° C Crawl for 2 hours the one under tension 0.01 $ 0 from 80 f> the breaking load 0.039 ^ Relaxation during 120 Hours at one voltage of, 0 ^ S .der 1.5 Breaking load 4.6 pounds

009886/0055

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A look at the two tables shows that skin-passaging at ambient temperature improves the breaking strength and the yield strength decreases, which are then increased again by tempering at 280 ° C, but without the Breaking strength would be practically higher than before tempering.

On the other hand, it follows from the above tables, that the erfindungsge.aäß skin-conditioning at 280 C the breaking strength and the stretching strength of the Jrahfces eri-öht. Furthermore It is found that the wires of the present invention improved Have creep and relaxation properties.

These characteristics are important as an i-'eder under constants Load tends to get under the effect of creeping to deform; The smaller the deformation, the better the spring is under constant load.

The prestressing force of reinforcement in prestressed concrete, which is kept at a constant length, is also reduced under the influence of the relaxation of the steel little by little, from which it follows that one is of great interest has the fact that the steels have a low relaxation.

Finally, it is found that the implementation of the method according to the invention does not require any special installations requires, and that it is realized through the unification of equipment currently used in the industry concerned can be.

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Claims (3)

Patent claims ]. Method for skin-passaging an elongated product made of carbon steel, '' especially for use in prestressed concrete, with high mechanical strength, tensile strength, Elongation and resistance to relaxation, being a starting 'material in J? orm of an elongated steel is patented, the dimensions of the cross-section of this material through Cold working are reduced and the resulting Limaterial is dressed, characterized in that the Skin pass through alternating bending in different radial planes at a temperature above the ambient temperature and takes place below the recrystallization temperature of the steel of the skin-passing product, and that the elongated product is then cooled to ambient temperature will. 2. The method according to claim 1, characterized in that that the dressing takes place above 200 ° C. 3. Steel wire and similar products of elongated shape, characterized in that they are made according to claim 1 or 2 are. Empty soap