SE414791B - SET AND DEVICE FOR PAPING AND HEAT FORMING OF WIRE - Google Patents

Description

'vueszss-u' i 2 'IO '15 20 25 50 55' Q-O .. even mined with. use of complicated heating systems and a shielding gas.

The direct heating is usually carried out in such a way that electric current is conducted through the steel wire and the resulting joule effect is utilized. In this method, the supply of current to the wire causes certain difficulties. In a known solution, a special mechanical contact device was used. However, this is not reliable enough, which is why the contact becomes unstable. In another known solution, the current is supplied through a metal bath (for example through a lead melt). With this solution, there is the disadvantage that the wire is immersed in the lead bath during bending (for example by means of rollers), so that the retraction of the wire is made more difficult at the start. Even with the above-mentioned direct e-heating methods, the formation of embers gives rise to worries. The further processing of the steel wire can in fact only take place after the ember shell has been removed, which, however, is time-consuming and costly. The embers are usually removed with the help of strong acids. However, the use of acids is partly risky, and partly dangerous to health (through acid vapors).

The second phase of the patenting process (the isothermal cooling) is usually carried out by immersing the wire in a lead or salt bath with that of the wire intended temperature. For immersion, deflection elements are used, for example rollers or rollers.

However, these elements are not sufficiently reliable and make the operation of the device cumbersome. An additional disadvantage of this solution is that the bath is heated to an elevated temperature in the area around the entry point of the hot wire, so that the required rapid cooling is not obtained and the wire has a reduced quality. To eliminate this difficulty, the bath is usually circulated using special pumps. However, these pumps make the device even more complicated and expensive, and the pumps are easily damaged by the unfavorable operating conditions.

The object of the invention is to eliminate the disadvantages of known solutions.

The invention relates to a method and a device, whereby patenting and thermoforming of steel wire Iran is carried out at high productivity while ensuring constant and good quality at low space requirements. The scaling on the steel wire is eliminated and at the same time the co-patenting, the wire can be formed in a hot state.

In the method according to the invention, the steel wire is passed through salt baths of 'different potentinl, vnrvfikl' lzr-.fïdan guides, '| f1or1' ..- xontc]]. A trawl through a preheating tray contained a salt bar and then a patented tray containing a salt bath, between control means arranged before and after the salt bath. '' IO '15 20 25 50 55 40 5 7lfå5256-4 For thermoforming during patenting, the section of the steel wire emanating from the patenting tray is moved at a greater speed than the wire tray coming into the preheating tray.

For carrying out the method according to the invention, a device is used comprising in a straight line successive preheating trays and patenting tubes, wherein the preheating tray is connected to one pole of one power source and the patenting tray to the other pole of the same power source. Both the preheating trough and the patenting trough consist of lower and upper troughs, grooves being provided in the inlet walls of the upper troughs at the points where the wire path intersects these walls, and the upper and lower troughs contain salt baths and are connected by a pump.

Furthermore, a first guide element arranged along the wire path before the preheating trough in the form of a first roller is included, and a second guide element arranged after the patenting trough in the form of a second roller, the latter roller receiving the wire with greater haste than the authoring roller.

An advantageous embodiment of the device according to the invention has three parallel, insulated preheating trays or pairs of tenting troughs, each of which is connected to a phase of a three-phase network, while the patenting trough or preheating trough is connected to the zero point of this network.

The pump that connects the lower and upper troughs to each other is suitably a so-called mother window pump.

The most important advantages of the invention are the following: - The beam wire runs without deflection through the patenting device, in some deflection elements are not required; - The direct heating of the steel wire is reliable and even when the power is supplied through the salt bath; o - The steel wire does not receive a scale, as the adhesive salt layer protects the wire from the oxygen in the air so that the use of shielding gas is unnecessary and otherwise required devices for removing the scale become unnecessary with accompanying disadvantages (space requirements, time, costs, acids); - The steel wire can be subjected to heat treatment (thermoforming) at the same time as the patenting, whereby the mechanical strength of the trees can be increased so that at the same time other technological parameters (breaking value, torsional value, etc.) can be improved; i - The heat treatment can be performed without tools; - This hot processing of the wire takes place where its structure is most suitable- (where the resistance to processing is least); - The double trough system provides constant circulation of the salt bath, ie. prevents local magnification heating of the bath, except that the system allows rectilinear control of the wire; 10 15 20 25 šO 55 LFO å? hß5256 'le i - The device is relatively simple and reliable, the mammoth pumbers used do not contain any moving parts, and the otherwise existing deflection elements immersed in the bath, the shielding gas system, etc. become unnecessary.

The invention is described below in the form of exemplary embodiments and with reference to the accompanying drawing.

Fig. 1 schematically shows a patenting and hot working device according to the invention in side view. Fig. 2 shows a cross-section through the device along the line A-A in Fig. D. 5 shows a cross section of the device along the line B-B in fig. 1.

The device according to the example consists of a first guide element, for example a roller 1, arranged at the horizontal guide plane of the parallel guided wires 7, further of three preheating trays 5, a patenting tray 9 and of the second guide element, for example the roller 2. Trays 3 and 9 lower 3 'and 9' respectively comprise upper 5 "and 9" metal troughs, which are provided with heating devices not shown in the figure. The lower 5 'and 9' and the upper 5 "and 9" troughs are connected to each other by pumps 6. The pumps 6 are suitably so-called mammoth pumps. In the direction of end walls of the upper troughs 5 "and 9" which are perpendicular to the direction of movement of the wires 7, grooves 8 are occupied at the points where the path of the wires intersects the end walls. The wires are guided through the upper troughs 5 "and 9" in such a way that their path lies below the upper edge of the end walls Scmen over the lowest point of the grooves 8. The lower 5 'and 9' and the upper 5 "and The 9 "troughs are filled with salt baths commonly used for patenting (saline solution or salt melt).

In the upper troughs the level of the salt bath is above the plane determined by the wires 7, and this level is maintained by means of appropriately controlled pumps 6, which continuously supply the salt bath flowing back through the grooves to the lower troughs.

The preheating trough 5 is connected to one pole of one power source and the patenting trough 9 to the other pole of the power source.

In the case shown, the preheating tray 5 suitably consists of three parts which are insulated from each other (Fig. 2). These parts are each connected to a phase R, S, T of a three-phase network, while the patented tray 9 consisting of a part is connected to the zero point of the network. This star connection of the troughs is advantageous, as the net will thereby be loaded evenly. A star coupling can of course also be arranged in such a way that the patenting trough is divided into three troughs.

The device operates as follows: The patented wires are fed through the first roller 1, then the wires are passed through the grooves 8 in the upper trough 5 "of the respective preheating trough 5 and the upper trough 9" of the patenting 10. 15 20 50 55 40 s 74052564: the trough 9 and then over the second roller 2. The first roller 4 rotates at a peripheral speed vq, and the second roller 2 at a peripheral speed V2. The wires 7 obtain the peripheral speed of the rollers. Since the wires 7 are only to be patented, the first roller 4 and the second roller 2 are rotated at an equal peripheral speed (v¿ = 2). When the wire is also to be hot-worked, the peripheral speed of the second roller 2 is increased in relation to the peripheral speed of the first roller 4 corresponding to the value of the desired cross-sectional reduction. The peripheral speed of the second roller 2 can under no circumstances be less than the peripheral speed of the first roller 1, as in such a case the wires 7 would be sprained and leave their intended path.

When the device is started, the pumps 6 are switched on and transport salt baths to the upper troughs 5 "and 9" from the lower troughs 5 'and 9'.

Then the troughs are put under tension. The different phases R, S, T are connected as follows: lower trough 5 ', pump 6, upper trough 5 ", wires 7, upper trough 9", pump 6, and lower trough 9'.

Under the influence of the current, the wires 7 are heated. The heating is strongest in the distance between the upper troughs 5 "and 9" and especially before the entry into the trough 9 ". There is the austenisation (annealing) of the wires 7. Before the entry into the upper trough 9 "the temperature of the wires 7 is about 900 ° C, after entering the salt bath the wires are rapidly cooled to a temperature of about 500 ° C (the temperatures are selected according to known principles depending on the type of wire) and kept at this temperature until they leave the upper trough 9. "(isothermal cooling distance).

The pumps return the salt bath carried out from the upper trays 5 "and 9", respectively carried by the wires 7, and at the same time circulate the salt bath, whereby excessive local heating of the bath can be prevented.

The wires 7 "emanating from the upper troughs 5" are protected by the adhesive salt layer from scaling during annealing.

If the threads are also to be hot-worked (hot-formed) at the same time as the patenting, the speed of the second roller 2 must be increased as required in comparison with the speed of the first roller 1. Since the speed of a stretch of the continuous stretched thread can only be increased the wires are extended in the places where they have the least deformation resistance, ie. before entering the upper trough 9 "(the cross section of the wires is reduced). This combined technology enables simultaneous patenting and thermoforming, whereby the thermoforming can be carried out without special forming tools.

The salt bath used in the troughs ensures good contact between the net and the wires, efficient preheating and good cooling retention, and at the same time protects the annealed wire section from scaling.

The preheating and patenting troughs must not necessarily be the same. 7lfß5256-4 e '10 '15 20 25 salt baths can be used, but for simplification reasons this is advantageous. In the preheating trough, salt baths are used with special advantage, which at annealing temperature do not develop any harmful fission products (with special regard to health risks) and which have good conductivity.

A patent salt bath should not unconditionally be used in the preheating tray.

According to experience, the product type 2000A Hertolwerk Magdeburg (DDR) is particularly suitable as a patenting salt, but other corresponding materials can be used.

The peripheral speed of the rollers, the composition and concentration of the salt bath, the current, the pump power, the heat development in the troughs are always selected and regulated in accordance with the present requirements. The patenting trough 9 is significantly longer than the preheating trough 3, corresponding to the time required for cooling. The various parts of the device must, of course, be provided with the necessary insulation with regard to operational safety, and devices must also be provided to protect the operating personnel from the effects of electricity.

According to experience, the method according to the invention can, at the same time as patenting and without special tools, achieve a 40% cross-sectional reduction of the wire. This increases the strength of the trees in such a way that its other mechanical and technological parameters (breaking value, torsional value, etc.) can also be improved. The wire runs rectilinearly and without any bending through the bath, receives no embers and is deformed where its structure is most suitable for deformation.

Claims (4)

10 45 20 25 50 7 '7405256-4 Eatentkrav 1. A method of patenting and thermoforming steel wire, wherein the wires are guided by salt baths of different potentials, characterized in that the wire is guided during movement in a straight path through a preheating tray containing a salt bath and then through a patenting tray containing a salt head between guides. arranged before and after the salt baths, and that the section of the wire leaving the patenting tray is moved at a greater speed than the distance entering the preheating tray. Device for patenting and thermoforming steel wire according to claim 1, characterized in that it comprises preheating troughs (5) and patenting troughs (9) arranged in a straight line, that the preheating trough (3) is connected to a pole of a power source and that the patenting trough (9) is connected to the other pole of the same power source, and that both the preheating trough (5) and also the patenting trough (9) consist of lower (š ', 9') and upper (š ", 9") troughs , grooves (8) being provided in the end walls (H) of the upper troughs (5 ", 9") at the points where the path of the steel wires (7) intersects these end walls, the upper (5 ", 9" ) and the lower (5 ', 9') trays contain salt baths and are connected to each other by pumps (6) and that a first guide means in the form of a roller (1) is arranged before the preheating trough (5) and a second guide means in the form of a roller (2) is arranged after the patenting trough (9), which second roller feeds the wire at a greater speed than the first roller. Device according to claim 2, characterized in that three parallel, insulated preheating trays (5) or patenting trays (9) are each connected to a phase (R, S, T) of an alternating current network, while the patenting tray (9) or the preheating wire (5) is connected to the zero point of this network. Device according to claim 2, characterized in that the pump (6) is a mammoth pump. of that of cited PUBLICATIONS: Germany 742 433, 876 695 US 3,163,566