JP4709666B2 - Loose coil in-line heat treatment equipment and in-line heat treatment method - Google Patents

Description

  The present invention relates to an in-line heat treatment facility and an in-line heat treatment method for a loose coil that is cooled with molten salt while transporting an austenite loose coil.

  Conventionally, when producing a medium or high carbon steel wire rod, the wire rod is hot-rolled for the purpose of imparting strength to the wire rod, and then reheated to the austenite state or austenite state as it is. There is known a heat treatment technique called patenting in which a material is rapidly cooled to a temperature of around 0 ° C. and transformed into fine pearlite.

  In particular, the direct heat treatment technique in which the above-described patenting is directly performed in-line following the rolling line so as to utilize the sensible heat of the loose coil immediately after hot rolling is called direct patenting. Patent Document 1 and Patent Document 2 disclose in-line heat treatment equipment that can be applied to a production line for producing a medium / high carbon steel wire by performing such direct patenting.

  When direct patenting is performed using the in-line heat treatment equipment described in Patent Documents 1 and 2, the austenite wire rod is turned into a continuous non-concentric ring coil in the rolling line, and then the loose coil is used. The heat treatment can be performed by transporting it in the cooling tank filled with the molten salt or the like downstream of the rolling line.

JP 59-31875 A Japanese Utility Model Publication No. 61-147255

  However, in the in-line heat treatment facilities described in Patent Documents 1 and 2, the bearings of a plurality of rollers that convey the loose coil while being immersed in the molten salt in the cooling bath are located on the upper portions of both side walls along the conveying direction of the cooling bath. Is provided. This is to enable grease lubrication of the bearing without immersing the fixed bearing in the molten salt. When such a bearing can be used, a driving means can be connected to the roller, so that the conveyance by the rotation of the roller can be realized smoothly.

  Due to such structural limitations, in the inline heat treatment facilities described in Patent Documents 1 and 2, the roller shafts of a plurality of rollers are directed from the bearings on the upper side walls of the cooling tank to the inside of the cooling tank and downward. It is inclined and arranged. For this reason, the plurality of rollers are arranged at the same position in the transport direction so as to be paired on both sides in the width direction orthogonal to the transport direction, and each roller pair cooperates to transport the loose coil. ing. Also, the roller has a conical shape so that the contact portion with the loose coil to be conveyed is horizontal.

  Therefore, in Patent Documents 1 and 2, when the loose coil is transported in the cooling tank, only the vicinity of both ends in the width direction of each ring portion of the loose coil is in contact with the rotating conical roller, Near the center in the width direction of each ring portion of the loose coil is not in contact with the conical roller. That is, since the contact area between the loose coil and the roller is small, the propulsive force during conveyance is very small, and the loose coil may be stagnated during conveyance. If the loose coil stagnates, the wire rolling line must be stopped.

  In addition, if the ring portions of the loose coil are not evenly in contact with both of the conical roller pairs arranged on both sides in the width direction during conveyance, propulsion by rotation of the two conical rollers forming the pair There is a difference in force, the loose coil cannot be properly advanced in the transport direction, and the loose coil may be biased, stagnated, or rotated, resulting in a fatal failure in the wire production line. . Moreover, if the loose coil is cooled in a biased state, the quality of the manufactured wire will be degraded.

  Furthermore, in Patent Documents 1 and 2, since the molten salt causes a non-uniform flow in the width direction due to the rotation of the conical rollers disposed on both sides in the width direction in the cooling tank, the cooling of the loose coil varies. As a result, the quality of the manufactured wire is degraded.

  The present invention has been made in view of the above problems, and when producing a wire material by cooling or isothermal treatment of an austenitic loose coil, the loose coil is more appropriately and reliably used as a molten salt in a cooling tank. It is an object of the present invention to provide a loose coil in-line heat treatment facility and an in-line heat treatment method capable of producing a high-quality wire rod while being dipped.

In order to solve the above problems, according to the present invention, in an in-line heat treatment facility for a loose coil that cools with a molten salt while conveying a loose coil in an austenitic state, a cooling tank filled with the molten salt, A flat roller having a structure in which a plurality of flat rollers penetrating both side walls in the width direction perpendicular to the conveying direction are arranged in parallel along the conveying direction and conveying the loose coil while being immersed in the molten salt in the cooling tank and the group is arranged on the lower side of said cooling tank, and receiving tank for receiving the molten salt flowing out from the cooling bath, the molten salt of the receiving vessel have a, a circulating means for returning to the cooling tank, the cooling bath, A tank member composed of a bottom plate and both side walls along the conveying direction of the loose coil is overlapped along the conveying direction so that adjacent ends in the conveying direction are nested. Characterized in that an arrangement with the structures, line heat treatment equipment of the loose coil is provided.

  In the in-line heat treatment equipment for the loose coil, the molten salt is applied from the outside of the cooling tank toward the gap between the inner peripheral surface of the through hole of the both side walls through which the flat roller passes and the outer peripheral surface of the flat roller. You may make it provide the injection nozzle which injects.

  In the in-line heat treatment equipment for the loose coil, the flat roller group is configured such that the vertical position of the flat roller disposed between the inlet side and the outlet side in the conveying direction of the loose coil in the cooling tank is in the cooling tank. You may be lower than the position of the said flat roller arrange | positioned at the entrance side and exit side of the conveyance direction of the said loose coil.

  In the above-described loose coil in-line heat treatment facility, a weir for injecting molten salt from an obliquely upper side to a vertical direction outside the cooling tank toward the flat rollers provided on the entry side and the exit side in the conveyance direction of the loose coil A nozzle may be provided.

According to the present invention, there is also provided an in-line heat treatment method for a loose coil in which a loose coil in an austenite state is conveyed and cooled with molten salt , comprising a bottom plate and both side walls along the conveyance direction of the loose coil. A plurality of tank members are arranged along the transport direction so that adjacent ends in the transport direction are nested and filled with molten salt, and both side walls of the cooling tank are transported By rotating a plurality of flat rollers penetrating in the width direction orthogonal to the direction in the same direction at a constant speed, the loose coils are conveyed on the plurality of flat rollers while being immersed in the molten salt of the cooling tank , A loose coil in-line heat treatment method is provided , wherein the molten salt flowing out of the cooling bath is circulated back to the cooling bath .

  In the in-line heat treatment method for the loose coil, when the loose coil is transported while being immersed in the molten salt in the cooling bath, the molten salt liquid in the cooling bath is moved while the loose coil is advanced from the inlet side of the cooling bath. It is possible to make it move down at a certain height and then move it up in the molten salt solution in the cooling bath and then lift it out from the outlet side of the cooling bath.

  In the in-line heat treatment method of the loose coil, when the loose coil is transported while being immersed in the molten salt of the cooling bath, from the upper side in the oblique direction to the upper side of the cooling bath, You may make it reduce the outflow amount of the molten salt of the said cooling tank which injects molten salt toward the said flat roller provided in the delivery side, and flows out of the said cooling tank.

  According to the present invention, when producing a wire by cooling or isothermal treatment of a loose coil in an austenite state, the loose coil is transported while being immersed in the molten salt of the cooling tank using a flat roller. The loose coil can be transported properly and reliably in the cooling tank, and the wire production line can be stabilized. This also makes it possible to produce high quality wires. Furthermore, according to the present invention, grease lubrication of the bearing of the flat roller becomes possible, and a driving means is connected to the roller, so that the conveyance by the rotation of the roller can be realized smoothly.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a configuration diagram of a wire production line 2 to which an in-line heat treatment facility 1 according to an embodiment of the present invention is applied. As shown in FIG. 1, the production line 2 includes, for example, a heat treatment line 4 for directly patenting the loose coil W downstream of the rolling line 3 for hot rolling a steel billet into a loose coil W in a continuous non-concentric ring state. It has the structure which provided. In the production line 2, the steel billet and the loose coil W are conveyed in the direction of the arrow (to the right in FIG. 1).

  The rolling line 3 includes a heating furnace 10 for heating the billet to the hot rolling temperature, a rough / intermediate rolling mill 11 for roughing / intermediate rolling of the heated billet, and a finishing rolling mill for rolling the rough / intermediate rolled billet into a wire rod. 12 and a winding machine 13 for winding the wire around a loose coil W in a continuous non-concentric ring state is arranged in order along the conveying direction. As shown in FIG. 1, the loose coil W formed by the winder 13 is conveyed to the downstream heat treatment line 4.

  The heat treatment line 4 includes an in-line heat treatment facility 1 for directly heat-treating (direct patenting) the loose coil W conveyed in a non-concentric ring state continuous from the upstream rolling line 3, and forming the directly heat-treated loose coil W into a coil. The converging device 15 is arranged in order along the transport direction. The in-line heat treatment equipment 1 includes a cooling device 20 that cools the loose coil W conveyed from the rolling line 3 to a temperature of, for example, around 500 ° C. with a molten salt, and the cooled loose coil W is predetermined to a temperature of, for example, 550 ° C. with a molten salt. A constant temperature device 21 for holding time and a cleaning device 22 for cleaning the loose coil W and collecting the adhering molten salt are arranged in order along the transport direction.

  FIG. 2 is a side view of the cooling device 20 provided in the in-line heat treatment facility 1 according to the embodiment of the present invention. In FIG. 2, the loose coil W is conveyed in the direction of the arrow (toward the right in FIG. 2). 3 is a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 2, the cooling device 20 includes a receiving tank 32 that receives the molten salt 30 flowing out of the cooling tank 31 below the cooling tank 31 filled with the molten salt 30 that cools the loose coil W. Have In the present embodiment, the receiving tank 32 has a rectangular parallelepiped shape with an upper surface opened. The cooling tank 31 also has a rectangular parallelepiped shape with an upper surface opened. The cooling tank 31 and the receiving tank 32 have an arrangement configuration in which the longitudinal direction thereof is parallel to the conveying direction of the loose coil W. The cooling tank 31 has both side walls along the conveying direction supported by an outer wall 47 (to be described later) by a support frame 39 and is fixed above the receiving tank 32. In addition, the cooling tank 31 and the receiving tank 32 may be manufactured by welding a steel plate etc., for example.

  The receiving tank 32 and the cooling tank 31 are connected by the following circulation means. That is, a pump 35 for sucking out the molten salt 30 stored in the receiving tank 32 is connected to the lower part of the receiving tank 32 through the pipe 36. The pump 35 is connected to a vertically downward return nozzle 37 provided above the cooling tank 31 via a pipe 36, and the molten salt 30 sucked from the receiving tank 32 is injected from these return nozzles 37. However, it can be returned to the cooling tank 31. In the present embodiment, the return nozzles 37 are arranged above the cooling tank 31 at predetermined intervals on the lower surfaces of a plurality of support bodies 40 provided in parallel with the width direction orthogonal to the transport direction.

  In the present embodiment, a refractory brick 45 is laid over the entire surface below the bottom surface of the receiving tank 32. In addition, an outer wall 47 made of, for example, a steel frame is provided over the entire surface on both sides of the receiving tank 32 along the conveying direction via a heat insulating material 46.

  The cooling tank 31 is a flat roller group 51 capable of transporting a loose coil W transported in a continuous non-concentric ring state by a plurality of transport rolls 50 from an upstream rolling line 3 while being immersed in the molten salt 30. It has. The flat roller group 51 has a configuration in which a plurality of flat rollers 52 penetrating the cooling tank 31 in the width direction are arranged in parallel along the transport direction. Both ends of each flat roller 52 in the width direction protrude through the cylindrical through-holes 56 provided in both side walls 55 along the conveying direction of the cooling bath 31 and protrude outward, and bearings 57 provided on the outer wall 47. It is supported in a rotatable manner. Thereby, each flat roller 52 can rotate at the same speed in the same direction around an axis parallel to the width direction, and can transport the loose coil W placed thereon. In the present specification, the term “flat roller” means a cylindrical roller having a flat outer peripheral surface.

  In the present embodiment, the vertical positions of the plurality of flat rollers 52 constituting the flat roller group 51 are cooled along the conveying direction of the loose coils W so that the loose coils W can be conveyed while being completely immersed. Within the tank 31, it gradually decreases from the entry side I toward the center between the entry side I and the exit side O. In the central part of the cooling tank 31, each position in the vertical direction of each flat roller 52 is set to a constant height immersed in the liquid, and gradually from the central part toward the outlet side O on the downstream side in the transport direction. It is high. That is, as shown in FIG. 2, the conveyance path surface of the loose coil W formed in the cooling tank 31 by the flat roller group 51 has a convex shape when viewed in the width direction orthogonal to the conveyance direction. The height of the outer wall 47 on which the bearings 57 that support both ends of the flat roller 52 are installed is gradually lowered from the entry side I toward the central portion, as in the flat roller 52, and is constant at the central portion. Then, it is set to gradually increase toward the exit side O.

  FIG. 4 is an enlarged cross-sectional view in which the through hole 56 of the cooling tank 31 through which the flat roller 52 passes is enlarged. As shown in FIG. 4, the cooling device 20 includes an inner peripheral surface of a cylindrical through hole 56 provided in the side wall 55 of the cooling tank 31 and an outer peripheral surface of the flat roller 52 that passes through the through hole 56. A ring-shaped seal 90 is provided to seal a very narrow and long gap formed therebetween.

  Next, the structure of the cooling tank 31 will be described. The cooling tank 31 includes a substantially rectangular bottom plate 65 that is disposed horizontally with its longitudinal direction parallel to the transport direction. On the bottom plate 65, both side walls 55 along the transport direction, and front walls 66 and rear walls (not shown) along the width direction are erected in the vertical direction at front and rear ends in the transport direction. FIG. 5 is a partial plan view showing the cooling tank 31 near the entry side in the conveying direction of the loose coil W so as to explain the configuration of the cooling tank 31.

  As shown in FIG. 5, the cooling tank 31 has a configuration in which a plurality of tank members 70 are arranged along the transport direction. Each tank member 70 is configured by a substantially rectangular bottom plate 71 arranged horizontally, and both side walls 72 erected in the vertical direction along the conveying direction at each of both end portions in the width direction of the bottom plate 71. . Each tank member 70 is arranged such that adjacent end portions 75 in the conveying direction are closely attached and overlapped in parallel at three locations of the bottom plate 71 and the side walls 72. That is, the bottom plate 65 of the cooling tank 31 is composed of the bottom plates 71 of the plurality of tank members 70, and the both side walls 55 of the cooling tank 31 are composed of the both side walls 72 of the plurality of tank members 70.

  In the present embodiment, each tank member 70 is provided with one flat roller 52. As shown in FIG. 5, a front wall 66 is erected in the vertical direction along the width direction at the end of the entire tank member 70 arranged in the conveyance direction I on the transport side I. Although not shown, a rear wall (not shown) is also erected along the width direction at the end of the entire tank member 70 on the delivery direction exit side O.

  The in-line heat treatment equipment 1 according to the embodiment of the present invention configured as described above is used to convey the loose coil W that has been rolled in the upstream rolling line 3 and then formed into a continuous non-concentric ring state. An in-line heat treatment method for cooling with the molten salt 30 will be described with reference to FIGS.

  In the rolling line 3 upstream of the heat treatment line 4, the steel billet is heated to the hot rolling temperature in the heating furnace 10, and is then subjected to rough / intermediate rolling with the rough / intermediate rolling mill 11 while conveying the billet, Finish rolling with a finish rolling machine 12 to form a wire. The wire is wound into a continuous non-concentric ring state by the winder 13 and formed into a loose coil W, and the loose coil W is transported to the downstream heat treatment line 4 by the transport roll 50.

  The loose coil W conveyed in a non-concentric ring state continuous from the rolling line 3 is conveyed to the cooling device 20. In the present embodiment, the loose coil W transported into the cooling bath 31 enters the flat roller group 51 from the transport roll 50 on the entry side I in the transport direction of the cooling device 20.

  The loose coil W is conveyed while being immersed in the molten salt 30 and cooled. That is, each flat roller 52 constituting the flat roller group 51 transports the loose coil W along the transport direction and gradually descends into the molten salt 30 while proceeding from the inlet side I of the cooling bath 31. After the loose coil W reaches the vertical position where it is completely immersed in the molten salt 30 solution, it proceeds at this height for a while and then gradually rises while proceeding near the outlet side of the cooling bath 31. .

  In the cooling device 20, the molten salt 30 used for cooling the loose coil W is circulated as follows. The molten salt 30 that has flowed out of the cooling tank 31 through the inlet I and outlet O in the conveying direction of the loose coil W, the through-hole 56 through which the flat roller 52 passes, or both side walls 55 is below the cooling tank 31. It receives and stores in the receiving tank 32 arrange | positioned. The molten salt 30 stored in the receiving tank 32 is returned to the cooling tank 31 through the following circulation path. That is, the molten salt 30 stored in the receiving tank 32 is sucked out by the pump 35 via the pipe 36 and sent to the return nozzle 37. By injecting the molten salt 30 from the return nozzle 37 to the cooling bath 31, the molten salt 30 flowing out of the cooling bath 31 is cooled by a heat exchanger (not shown) and then returned to the cooling bath 31 via the receiving bath 32. .

  The loose coil W cooled in the cooling bath 31 is conveyed to the thermostatic device 21. In the present embodiment, the loose coil W transported into the thermostatic device 21 is withdrawn from the flat roller group 51 of the cooling bath 31 to the transport roll 50 on the outlet side O in the transport direction of the cooling device 20. The loose coil W is held in a constant temperature apparatus 21 at a temperature of 550 ° C. for a predetermined time, for example, by being transported while being immersed in the molten salt 30. Thereafter, the loose coil W located downstream of the thermostatic device 21 is transported to the cleaning device 22.

  In the cleaning device 22, the molten salt 30 adhering to the loose coil W is removed and collected, and then transferred to the converging device 15 downstream of the cleaning device 22. The loose coil W conveyed to the converging device 15 is formed into a coil, and the processing in the wire production line 2 is completed.

  According to the above embodiment, when the loose coil W is transported while being immersed in the molten salt 30 of the cooling bath 31, the loose coil W and the flat roller are transported using the flat roller 52. The contact area with 52 becomes larger than that of the conventional one, the propulsive force during conveyance increases, and the loose coil W can be reliably conveyed without stagnation. In addition, unlike the conventionally known conical roller that contacts only both ends in the width direction of the loose coil, the flat roller 52 contacts the entire loose coil W. It is possible to transport it. Further, grease lubrication can be applied to the bearing as in the case of conventionally known rollers. In addition, when such a bearing can be used, a driving means can be connected to the roller to smoothly carry the roller by rotation. Due to the above advantages, the wire production line 2 can be stabilized. Further, since the loose coil W is uniformly cooled, a high quality wire can be manufactured. In particular, even when the transport path for transporting the loose coil W while being immersed in the molten salt includes an uphill, the transport speeds of the front end, the center, and the rear end in the transport direction of the loose coil W are generally set. Since it can be kept constant and the cooling time can be approximately the same, a wire rod that is more uniform than the conventional wire can be manufactured in the conveying direction.

  Furthermore, the cooling tank 31 has a configuration in which a plurality of tank members 70 are arranged along the transport direction so that the end portions 75 of the transport direction are overlapped with each other. Each of the tank members 70 can be dispersed in each thermal expansion in the transport direction (that is, each thermal expansion in the transport direction of the bottom plate 71 and the side walls 72). Thereby, it is possible to prevent the flat roller 52 supported by each fixed bearing 57 and the through holes 56 of the side walls 72 from being eccentrically displaced due to thermal expansion, and the transport path surface formed by the group of flat rollers 51 can be prevented. It is possible to stabilize. As a result, the loose coil W can be transported appropriately and reliably in the transport direction, the wire production line 2 can be stabilized, and the loose coil W can be uniformly cooled to produce a high-quality wire. It is.

  As a second embodiment of the present invention, instead of the ring-shaped seal 90 described above, an inner peripheral surface of a cylindrical through hole 56 provided on both side walls 55 of the cooling bath 31 and the through hole 56 are provided. You may provide the ring-shaped injection nozzle 60 which injects the molten salt 30 from the outer side of the cooling tank 31 toward the very narrow long gap formed between the outer peripheral surfaces of the flat roller 52 which penetrates. As described above, by using the injection nozzle 60 to inject the molten salt from the outside of the cooling tank 31 toward the gap, it is possible to suppress the flow of the molten salt that is about to leak from the gap. FIG. 6 is an enlarged cross-sectional view in which the through hole 56 of the cooling tank 31 having the ring-shaped injection nozzle 60 is enlarged.

  According to the second embodiment described above, the inner peripheral surface of the cylindrical through-hole 56 provided in the both side walls 55 of the cooling tank 31 and the outer peripheral surface of the flat roller 52 that passes through the through-hole 56. It is possible to reduce the outflow amount of the molten salt 30 flowing out from the gap formed between them by the structure in which the flat roller 52 easily rotates. The second embodiment also has the same effect as the first embodiment.

  As a third embodiment of the present invention, the loose coil W may be transported in the cooling tank 31 from the entry side I to the exit side O in the horizontal direction. FIG. 7 is a schematic side view of the cooling device 20 according to the third embodiment of the present invention in which all the flat rollers 52 constituting the flat roller group 51 are arranged in the same horizontal plane.

  As shown in FIG. 7, the cooling device 20 includes an inlet side weir nozzle that injects molten salt from the upper side to the lower side of the cooling tank 31 on the inlet side I and outlet side O in the conveying direction of the loose coil W 80 and an exit weir nozzle 81 are provided. In the present embodiment, flat nozzles having substantially the same width as the cooling tank 20 are used as the inlet dam nozzle 80 and the outlet dam nozzle 81.

  The inlet weir nozzle 80 injects the molten salt 30 obliquely downward from the upper side of the cooling tank 31 and upstream in the conveying direction toward the upper side of the flat roller 52 on the inlet side I in the conveying direction of the cooling device 20. It is configured. Similarly, the exit-side dam nozzle 81 extends obliquely downward or vertically downward from above the cooling tank 31 and downstream in the transport direction toward directly above the flat roller 52 on the exit side O in the transport direction of the cooling device 20. It is comprised so that the molten salt 30 may be injected.

  In the third embodiment of the present invention, the molten salt 30 stored in the receiving tank 32 is sucked out by the pump 35 via the pipe 36, and is returned to the return nozzle 37, the inlet dam nozzle 80, and the outlet dam nozzle. 81 to be sent. In addition, the vertical heights of the front walls (not shown) provided on the entry side I and the exit side O in the conveying direction of the entire disposed tank member 70 are set lower than the upper surface of the flat roller 52. . A rear wall (not shown) lower than the upper surface of the flat roller 52 is also erected along the width direction at the end of the tank member 70 on the outlet side O in the conveyance direction. Note that the front and rear walls at both ends in the transport direction are lower than both side surfaces along the transport direction.

  As described above, the molten salt 30 is injected from the inlet dam nozzle 80 and the outlet dam nozzle 81 and flows out from the front wall and the rear wall (not shown) of the cooling tank 31. The height of the liquid surface of the molten salt 30 in the cooling tank 31 is set to a position higher than the front wall and the rear wall (not shown) (the upper portion of the flat roller 52). It is possible to hold it at a certain height).

  According to the third embodiment described above, it is possible to immerse the loose coil W in the molten salt 30 of the cooling bath 31 while transporting the loose coil W in the cooling bath 31 in the horizontal direction. Since the surface can be simplified by making it a horizontal plane, the loose coil W can be easily transported appropriately in the transport direction. Further, the third embodiment has the same effect as the first embodiment.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to the example which concerns. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  In the embodiment described above, the rolling line 3 provided upstream of the heat treatment line 4 includes a heating furnace 10, a rough / intermediate rolling mill 11, a finish rolling mill 12 and a rolling mill along the billet (loose coil W) conveying direction. Although the case where the winder 13 is arranged has been described, the rolling line 3 may have other arrangements and configurations.

  In the embodiment described above, the heat treatment line 4 has been described with respect to the case where the cooling device 20 and the converging device 15 are arranged along the conveyance direction of the loose coil W. However, the heat treatment line 4 has other arrangements and configurations. There may be.

  In the embodiment described above, the case where the cooling device 20 includes the constant temperature device 21 and the cleaning device 22 has been described. However, the cooling device 20 may have other arrangements and configurations.

  In the above-described embodiment, the case where the molten salt 30 stored in the receiving tank 32 is returned to the cooling tank 31 using the pump 35 has been described. However, the molten salt 30 is transferred to the cooling tank 31 using a circulating means other than the pump 35. You may return.

  In the embodiment described above, the case where the inlet dam nozzle 80 and the outlet dam nozzle 81 are flat nozzles has been described. However, the inlet dam nozzle 80 and the outlet dam nozzle 81 are other than the flat nozzle. It may be a nozzle.

  In the above-described embodiment, the case where the inlet dam nozzle 80 and the outlet dam nozzle 81 inject the molten salt 30 downward from the upper oblique direction is described. You may make it inject. Alternatively, the inlet dam nozzle 80 and the outlet dam nozzle 81 may inject the molten salt 30 onto the upper surfaces of the walls provided on the inlet side I and outlet side O of the tank member 70 from obliquely above.

  In the embodiment described above, it is formed between the inner peripheral surface of the cylindrical through hole 56 provided in the both side walls 55 of the cooling tank 31 and the outer peripheral surface of the flat roller 52 that passes through the through hole 56. Although the case where the ring-shaped seal 90 that seals the gap is used has been described, other shapes of seals may be used.

  In the above-described embodiment, the case where all the plurality of flat rollers 52 rotate in the same direction at the same speed has been described. However, the rotation direction and the rotation speed of the plurality of flat rollers 52 may be set separately.

  In the above-described embodiment, the flat roller 52 is arranged so that the conveyance path surface of the loose coil W formed in the cooling tank 31 by the flat roller group 51 is parallel to the horizontal direction, and the convex roller is projected downward. Although the case where each flat roller 52 is arranged so as to have a shape has been described, the conveyance path surface of the loose coil W formed in the cooling tank 31 by the flat roller group 51 may have other shapes. .

  The present invention can be applied to, for example, an in-line heat treatment facility for producing a medium / high carbon steel wire using direct patenting, but is also useful for other in-line heat treatment facilities.

It is a lineblock diagram of wire manufacturing line 2 to which in-line heat treatment equipment 1 concerning an embodiment of the invention was applied. It is a side view of cooling device 20 with which in-line heat treatment equipment 1 concerning an embodiment of the invention is provided. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. It is the expanded sectional view which expanded the through-hole 56 of the cooling tank 31 which the flat roller 52 penetrates. FIG. 3 is a partial plan view showing the cooling tank 31 near the entry side I in the conveying direction of the loose coil W so as to explain the configuration of the cooling tank 31 in detail. It is the expanded sectional view which expanded the through-hole 56 of the cooling device 20 provided with the ring-shaped injection nozzle 60 concerning 2nd Embodiment. It is a schematic side view of the cooling device 20 with the flat roller 52 which comprises the flat roller group 51 concerning 3rd Embodiment arrange | positioned on the same horizontal surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 In-line heat treatment equipment 2 Wire production line 3 Rolling line 4 Heat treatment line 10 Heating furnace 11 Coarse / intermediate rolling mill 12 Finish rolling mill 13 Winding machine 15 Converging device 20 Cooling device 21 Constant temperature device 22 Cleaning device 30 Molten salt 31 Cooling tank 32 receiving tank 39 support frame 35 pump 36 pipe 37 return nozzle 40 support body 45 refractory brick 46 heat insulating material 47 outer wall 50 transport roll 51 flat roller group 52 flat roller 55 both side walls of cooling tank 56 through hole 57 bearing 60 jet nozzle 65 cooling The bottom plate of the tank 66 The front wall of the cooling tank 70 The tank member 71 The bottom plate of the tank member 72 The both side walls of the tank member 75 The ends in the transport direction of the tank member 80 The inlet side weir nozzle 81 The outlet side weir nozzle 90 The seal I of the cooling device Entry side in conveyance direction O Exit side in conveyance direction of cooling device W Loose coil

Claims (7)

In an in-line heat treatment facility for loose coils that cools with molten salt while transporting austenite loose coils,
A cooling bath filled with molten salt;
While having a configuration in which a plurality of flat rollers penetrating both side walls of the cooling tank in the width direction perpendicular to the conveying direction are arranged in parallel along the conveying direction, while immersing the loose coil in the molten salt of the cooling tank A group of flat rollers to be conveyed;
A receiving tank that is disposed below the cooling tank and receives the molten salt flowing out of the cooling tank;
Have a, a circulating means for returning the molten salt of the receiving tank to the cooling bath,
The cooling tank includes a tank member composed of a bottom plate and the both side walls along the conveyance direction of the loose coil, along the conveyance direction such that adjacent ends in the conveyance direction are nested. Loose coil in-line heat treatment equipment, characterized in that it has a multiple arrangement . An injection nozzle for injecting molten salt from the outside of the cooling tank toward the gap between the inner peripheral surface of the through hole of the both side walls through which the flat roller passes and the outer peripheral surface of the flat roller; The in-line heat treatment equipment for a loose coil according to claim 1, characterized in that In the flat roller group, the vertical position of the flat roller disposed between the inlet side and the outlet side of the cooling tank is the vertical position of the flat roller disposed on the inlet side and the outlet side of the cooling tank. The in-line heat treatment equipment for a loose coil according to claim 1, wherein the heat treatment equipment is lower. A weir nozzle is provided for injecting molten salt toward the flat rollers provided on the entry side and the exit side in the conveying direction of the loose coil from the upper side in the oblique direction to the upper side in the vertical direction outside the cooling tank. The in-line heat treatment equipment for a loose coil according to any one of claims 1 to 3. A loose coil in-line heat treatment method that cools with molten salt while transporting the austenite loose coil,
A plurality of tank members composed of a bottom plate and both side walls along the conveyance direction of the loose coil are arranged along the conveyance direction so that adjacent ends in the conveyance direction are nested. Filling a cooling bath with molten salt,
By rotating a plurality of flat rollers that penetrate both side walls of the cooling tank in the width direction orthogonal to the conveying direction in the same direction at a constant speed, the loose coil is moved on the molten salt of the cooling tank on the plurality of flat rollers. Transport while immersed in
A loose coil in-line heat treatment method, wherein the molten salt flowing out of the cooling bath is circulated back to the cooling bath. When the loose coil is transported while being immersed in the molten salt in the cooling tank, the loose coil is moved down from the inlet side of the cooling tank while being lowered in the molten salt liquid of the cooling tank. 6. The in-line heat treatment of a loose coil according to claim 5, wherein the in-line heat treatment of the loose coil according to claim 5, wherein the in-line heat treatment is carried out at a height, and then lifted while proceeding in a molten salt solution of the cooling bath. Method. When the loose coil is transported while being immersed in the molten salt of the cooling tank, the flat rollers provided on the inlet side and the outlet side of the cooling tank from the upper side in the oblique direction to the upper side in the vertical direction on the outer side of the cooling tank. The in-line heat treatment method for a loose coil according to claim 5 or 6, wherein the molten salt is sprayed toward the outside and the amount of molten salt flowing out of the cooling tank flowing out of the cooling tank is reduced.

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