Method for preventing high-line threaded steel finished product from being discharged

Abstract

The present application relates to the technical field of rolled steel thread steel wire rod production, in particular to a method for preventing high thread steel finished product from being punched out, comprising: sequentially rolling the blank by using a rough rolling mill group, a medium rolling mill group, a pre-precision rolling mill group, a BGV mill group and a reducing sizing mill group; the rough rolling mill group comprises No. 1-No. 6 rolling mills, the medium rolling mill group comprises No. 7-No. 12 rolling mills, the pre-precision rolling mill group comprises No. 13-No. 18 rolling mills, the BGV mill group comprises No. 19-No. 26 rolling mills, and the reducing sizing mill group comprises No. 27-No. 30 rolling mills; wherein, after rolling by using the pre-precision rolling mill group, the blank is cooled by using a first water tank and a second water tank; and after rolling by using the BGV mill group, the blank is cooled by using a third water tank and a fourth water tank; when cooling by using each water tank, the steel head part of a certain length needs not to be cooled. The method can improve the problem of the thread steel finished product being punched out, so as to ensure that the production of the thread steel can be stably carried out.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rolled steel thread steel wire rod production, in particular to a method for preventing high-line thread steel finished product from being discharged. BACKGROUND

[0002] In the production process of thread steel, the main rolling line is generally composed of a rough rolling mill group of 6 rolling mills, a medium rolling mill group of 6 rolling mills, a pre-precision rolling mill group of 6 rolling mills, a BGV mill group of 8 rolling mills, and a reducing and sizing mill group of 4 rolling mills.

[0003] However, the phenomenon of thread steel finished product hooking and being discharged frequently occurs when the last rolling mill of the main rolling line is rolled (the last pass), which causes the production of thread steel to be difficult to proceed stably. SUMMARY

[0004] The present application aims to provide a method for preventing high-line thread steel finished product from being discharged, which can improve the problem of thread steel finished product being discharged to ensure that the production of thread steel can proceed stably.

[0005] The embodiments of the present application can be implemented as follows:

[0006] The present application provides a method for preventing high-line thread steel finished product from being discharged, comprising:

[0007] The billet is sequentially rolled by the rough rolling mill group, the medium rolling mill group, the pre-precision rolling mill group, the BGV mill group, and the reducing and sizing mill group; the rough rolling mill group includes rolling mills No. 1-6, the medium rolling mill group includes rolling mills No. 7-12, the pre-precision rolling mill group includes rolling mills No. 13-18, the BGV mill group includes rolling mills No. 19-26, and the reducing and sizing mill group includes rolling mills No. 27-30; wherein,

[0008] After rolling by the pre-precision rolling mill group, the first water tank and the second water tank are also used for cooling; and after rolling by the BGV mill group, the third water tank and the fourth water tank are also used for cooling;

[0009] When cooling by the first water tank, the steel head with a length of 15-18 cm is not cooled;

[0010] When cooling by the second water tank, the steel head with a length of 12-15 cm is not cooled;

[0011] When cooling by the third water tank, the steel head with a length of 15-18 cm is not cooled;

[0012] When cooling by the fourth water tank, the steel head with a length of 12-15 cm is not cooled.

[0013] In the optional embodiment, the step of rolling by using the 30th rolling mill comprises the following steps: marking the upper and lower roll lateral ribs and extending the marks to the end surface of the roll before installing the roll ring, and aligning the marks of the upper and lower roll when installing the marked roll ring.

[0014] In the optional embodiment, the billet is sequentially rolled by using the rough rolling mill set, the medium rolling mill set, the pre-precision rolling mill set, the BGV mill set and the reducing sizing mill set, and the method further comprises the following steps:

[0015] When the specification of the produced threaded steel is Φ6mm, the 18th rolling mill in the pre-precision rolling mill set is controlled so that the tolerance diameter range after rolling is 19.3mm-19.7mm, and the out-of-roundness is ≤0.4mm; the 19th-26th rolling mills in the BGV mill set are controlled to be rolled for 8 passes, and the tolerance diameter range after rolling is 7.8mm-8.1mm, and the out-of-roundness is ≤0.25mm; the temperature of the head of the rolled piece entering the BGV mill set is controlled to be ≥960℃, the temperature of the head of the rolled piece entering the reducing sizing mill set is controlled to be ≥950℃; and the depth of the lateral rib of the finished roll ring after rolling by the 30th rolling mill is 0.6mm.

[0016] In the optional embodiment, when the specification of the produced threaded steel is Φ6mm, the opening rolling temperature is 950-1000℃, and the finish rolling temperature is 925-955℃.

[0017] The rolling speed of the 18th rolling mill is 10.51m / s, the rolling speed of the 26th rolling mill in the BGV mill set is 63.1m / s, and the rolling speed of the reducing sizing mill set is 80.7m / s in the early stage and 105m / s in the later stage.

[0018] In the optional embodiment, the billet is sequentially rolled by using the rough rolling mill set, the medium rolling mill set, the pre-precision rolling mill set, the BGV mill set and the reducing sizing mill set, and the method further comprises the following steps:

[0019] When the specification of the produced threaded steel is Φ8mm, the 18th rolling mill in the pre-precision rolling mill set is controlled so that the tolerance diameter range after rolling is 19.3mm-19.7mm, and the out-of-roundness is ≤0.4mm; the 4 rolling mills in the BGV mill set are controlled to be rolled for 4 passes, and the tolerance diameter range after rolling is 12.4mm-12.7mm, and the out-of-roundness is ≤0.25mm; the temperature of the head of the rolled piece entering the BGV mill set is controlled to be ≥960℃, the temperature of the head of the rolled piece entering the reducing sizing mill set is controlled to be ≥950℃; and the depth of the lateral rib of the finished roll ring after rolling by the 30th rolling mill is 0.7mm.

[0020] In the optional embodiment, when the specification of the produced threaded steel is Φ8mm, the opening rolling temperature is 950-1000℃, and the finish rolling temperature is 955-985℃.

[0021] The rolling speed of the 18th rolling mill is 16.09 m / s, the rolling speed of the 22nd rolling mill in the BGV mill train is 39.43 m / s, the rolling speed of the former stage of the reducing and sizing mill train is 57.18 m / s, and the rolling speed of the later stage of the reducing and sizing mill train is 91.5 m / s.

[0022] In the optional embodiment, the billet is sequentially rolled by the rough rolling mill train, the intermediate rolling mill train, the pre-finishing rolling mill train, the BGV mill train, and the reducing and sizing mill train, and the method further comprises the following steps:

[0023] When the specification of the produced threaded steel is Φ10 mm, the 18th rolling mill in the pre-finishing rolling mill train is controlled to make the tolerance diameter range of the rolled product be 19.3-19.7 mm, and the out-of-roundness be ≤0.4 mm; two rolling mills in the BGV mill train are controlled to be rolled for two passes, and the tolerance diameter range of the rolled product be 15.6-16.0 mm, and the out-of-roundness be ≤0.3 mm; the temperature of the head of the rolled product entering the BGV mill train is controlled to be ≥940℃, the temperature of the head of the rolled product entering the reducing and sizing mill train is controlled to be ≥930℃; and the depth of the cross rib of the finished product roll ring rolled by the 30th rolling mill is 0.9 mm.

[0024] In the optional embodiment, when the specification of the produced threaded steel is Φ10 mm, the starting rolling temperature is 950-1000℃, and the final rolling temperature is 955-985℃.

[0025] The rolling speed of the 18th rolling mill is 16.38 m / s, the rolling speed of the 20th rolling mill in the BGV mill train is 24.5 m / s, the rolling speed of the former stage of the reducing and sizing mill train is 36.6 m / s, and the rolling speed of the later stage of the reducing and sizing mill train is 58.6 m / s.

[0026] In the optional embodiment, the billet is sequentially rolled by the rough rolling mill train, the intermediate rolling mill train, the pre-finishing rolling mill train, the BGV mill train, and the reducing and sizing mill train, and the method further comprises the following steps:

[0027] When the specification of the produced threaded steel is Φ12 mm, the 18th rolling mill in the pre-finishing rolling mill train is controlled to make the tolerance diameter range of the rolled product be 19.3-19.7 mm, and the out-of-roundness be ≤0.4 mm; two rolling mills in the BGV mill train are controlled to be rolled for two passes, and the tolerance diameter range of the rolled product be 15.6-16.0 mm, and the out-of-roundness be ≤0.3 mm; the temperature of the head of the rolled product entering the BGV mill train is controlled to be ≥940℃, the temperature of the head of the rolled product entering the reducing and sizing mill train is controlled to be ≥930℃; and the depth of the cross rib of the finished product roll ring rolled by the 30th rolling mill is 1.1 mm.

[0028] In the optional embodiment, when the specification of the produced threaded steel is Φ12 mm, the starting rolling temperature is 950-1000℃, and the final rolling temperature is 875-905℃.

[0029] The rolling speed of the No. 18 rolling mill is 15.93 m / s, the rolling speed of the No. 20 rolling mill in the BGV mill train is 23.9 m / s, the rolling speed of the front stage of the reducing mill train is 30.83 m / s, and the rolling speed of the rear stage is 40.7 m / s.

[0030] The method for preventing the high-speed wire reinforced steel product from being punched out has the following beneficial effects:

[0031] The method for preventing the high-speed wire reinforced steel product from being punched out provided by the embodiment of the present application ensures that the head of the rolled piece is in a certain high-temperature state when entering the reducing mill train for rolling, improves the flatness of the rolled piece entering the last rolling mill, avoids the bending of the head of the rolled piece caused by the previous pass from affecting the running direction of the head of the rolled piece in the next pass, and ensures that the rolled piece can smoothly pass through the outlet of the last rolling mill and enter the induction channel, thereby improving the problem of the product being punched out. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0033] Figure 1 It is a schematic diagram of the identification of the upper and lower roll horizontal rib tooth edge in the present application;

[0034] Figure 2 It is a schematic diagram of the identification alignment of the upper and lower roll in the present application;

[0035] Figure 3 It is a temperature curve diagram of the embodiment 1 of the present application;

[0036] Figure 4 It is a temperature curve diagram of the comparative example 2 of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the application claimed, but merely represents selected embodiments of the application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the application without creative labor fall within the scope of the application.

[0039] It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0040] It should be noted that the features in the embodiments of the application can be combined with each other without conflict.

[0041] The application provides a method for preventing high-line threaded steel product from being punched out, which can effectively improve the problem of threaded steel product being punched out, so as to ensure that the production of threaded steel can be stably carried out.

[0042] It should be noted that the above-mentioned "punched out" refers to that after the last pass in the rolling process, for example, the product is punched out from the 30-stand, due to the bending phenomenon of the head of the product, the product cannot be smoothly punched into the outlet in place, and the outlet after the roll ring is punched.

[0043] It should be noted that the above-mentioned "high line" refers to the wire rod rolled by the "high-speed non-twist rolling mill".

[0044] The method for preventing high-line threaded steel product from being punched out comprises: rolling the billet by a rough rolling mill group, a medium rolling mill group, a pre-precision rolling mill group, a BGV mill group and a reducing and sizing mill group in sequence; the rough rolling mill group comprises No. 1-6 rolling mills, the medium rolling mill group comprises No. 7-12 rolling mills, the pre-precision rolling mill group comprises No. 13-18 rolling mills, the BGV mill group comprises No. 19-26 rolling mills, and the reducing and sizing mill group comprises No. 27-30 rolling mills, wherein the No. 30 rolling mill is the last pass.

[0045] In the application, four water tanks are arranged in the main rolling line, wherein the first water tank and the second water tank connected with each other are arranged after the pre-precision rolling mill group, and optionally, the first water tank and the second water tank are arranged after the No. 18 rolling mill (downstream of the process flow); the third water tank and the fourth water tank connected with each other are arranged after the BGV mill group, and optionally, the third water tank and the fourth water tank are arranged after the No. 26 rolling mill (downstream of the process flow); the method for preventing high-line threaded steel product from being punched out further comprises: after rolling by the pre-precision rolling mill group, the first water tank and the second water tank are further used for cooling, and after rolling by the BGV mill group, the third water tank and the fourth water tank are further used for cooling.

[0046] In order to improve the problem of the threaded steel product punching out, when the first water tank is used for cooling, the steel head of 15-18 cm long is not cooled, that is, the part of the steel head of 15-18 cm long (for example, 15 cm, 16 cm, 18 cm, etc.) is not subjected to water cooling; when the second water tank is used for cooling, the steel head of 12-15 cm long is not cooled, that is, the part of the steel head of 12-15 cm long (for example, 12 cm, 14 cm, 15 cm, etc.) is not subjected to water cooling; when the third water tank is used for cooling, the steel head of 15-18 cm long is not cooled, that is, the part of the steel head of 15-18 cm long (for example, 15 cm, 16 cm, 18 cm, etc.) is not subjected to water cooling; when the fourth water tank is used for cooling, the steel head of 12-15 cm long is not cooled, that is, the part of the steel head of 12-15 cm long (for example, 12 cm, 13 cm, 15 cm, etc.) is not subjected to water cooling.

[0047] In the cooling operation after the pre-finishing rolling mill set is rolled and after the BGV mill set is rolled, a part of the steel head is kept not to be cooled, so that the head of the rolled piece is in a certain high temperature state when entering the reducing sizing mill set for rolling, the flatness of the rolled piece entering the last rolling mill is improved, the bending of the head of the rolled piece caused by the last pass is avoided to affect the head of the rolled piece in the next pass, and it is ensured that the rolled piece can smoothly pass through the exit guide of the last rolling mill, thereby improving the problem of the product punching out, that is, a part of the steel head of a certain length is set to be not cooled, so as to ensure the temperature of the head of the rolled piece entering the BGV mill set and the reducing sizing mill set, reduce the bending of the steel head caused by water cooling, and further reduce the bending of the head of the product after rolling, so as to ensure that the rolled piece can smoothly enter the exit guide.

[0048] It should be noted that when the first water tank, the second water tank, the third water tank and the fourth water tank are used for cooling, there is a part of the steel head that is not cooled, and in the production process, the head of the rolled piece can be moved out of each water tank before cooling is started, so as to avoid accidental cooling of the steel head that does not need to be cooled.

[0049] It should be further noted that when the steel head has not been moved out of the water tank, the cooling water outlet can be blocked first to ensure that the steel head will not be subjected to water cooling. In some embodiments, a flying shear can be arranged in the BGV mill set to cut off the steel head whose temperature is accidentally reduced, so that the steel head entering the BGV mill set is not cooled.

[0050] Optionally, the temperature detection device can be arranged in the 19th-26th rolling mills of the BGV mill set, and when it is detected that the temperature of the steel head is higher than the temperature of the rolled piece after the first water tank and the second water tank are started, it is indicated that the steel head (the head of the rolled piece) has not been subjected to water cooling in the first water tank and the second water tank.

[0051] In order to further ensure that the steel head does not produce bending and punching out, please refer to Figure 1 and Figure 2The method for preventing high-line screw steel finished product from being discharged also comprises the following steps: before the step of rolling by using the No. 30 rolling mill, marking the upper and lower rollers at the tooth edge of the transverse rib and extending the mark to the end surface of the roller before installing the roller ring, and aligning the marks of the upper and lower rollers when installing the marked roller ring. In this way, the upper and lower rollers are aligned when being installed by marking, so as to eliminate the upper and lower pressure difference caused by the stagger of the inner diameter and the transverse rib in the rolling process, and further avoid the phenomenon of hooking after the rolled piece becomes the finished product. Moreover, before rolling by the No. 30 rolling mill, a part of the steel head is not cooled when being cooled by each water tank, so that the steel head will not be bent due to cooling, and the deformation of the rolled piece entering the No. 30 rolling mill is stable, and the flatness of the rolled piece entering the No. 30 rolling mill is ensured. In combination with the marking on the roller ring to optimize the assembly of the roller ring and eliminate the upper and lower pressure difference, the flatness of the head after the rolled piece exits the No. 30 rolling mill is ensured, and the head will not be bent to smoothly pass through the exit of the No. 30 rolling mill (the last pass) and enter the channel, so as to effectively improve the problem of the finished product being discharged from the No. 30 rolling mill.

[0052] It should be noted that, compared with the way of directly aligning the hole groove and the crescent of the upper and lower roller rings in the related art, the way of ensuring the alignment of the upper and lower rollers by marking the tooth edge of the transverse rib before installing the roller ring and extending the mark to the end surface of the roller has the advantages of convenience and easy operation, and can further effectively ensure the alignment of the upper and lower rollers.

[0053] In a more preferable embodiment, different numbers of passes can be rolled according to different specifications of the screw steel, and the number of passes is smaller when the diameter of the specification is larger. The specific rolling operation comprises the following steps:

[0054] When the specification of the produced screw steel is Φ6mm, the No. 18 rolling mill in the pre-rolling mill group is controlled, so that the tolerance diameter range after rolling is 19.3mm-19.7mm (for example: 19.3mm, 19.5mm, 19.7mm, etc.), and the out-of-roundness is ≤0.4mm; the No. 19-No. 26 rolling mill of the BGV mill group is controlled to roll for 8 passes, and the tolerance diameter range after rolling is 7.8mm-8.1mm (for example: 7.8mm, 8.0mm, 8.1mm, etc.), and the out-of-roundness is ≤0.25mm; the temperature of the head of the rolled piece entering the BGV mill group is controlled to be ≥960℃, the temperature of the head of the rolled piece entering the reducing mill group is controlled to be ≥950℃; and the depth of the transverse rib of the finished product roller ring after rolling by the No. 30 rolling mill is 0.6mm.

[0055] Further, when the specification of the produced threaded steel is Φ6mm, the rough rolling temperature is 950-1000℃ (for example: 950℃, 980℃, 1000℃, etc.), the finish rolling temperature is 925-955℃ (for example: 925℃, 940℃, 955℃, etc.); the rolling speed of the 18# rolling mill is 10.51m / s, the rolling speed of the 26# rolling mill in the BGV unit is 63.1m / s, the rolling speed of the former stage of the reducing sizing unit is 80.7m / s, and the rolling speed of the later stage is 105m / s.

[0056] When the specification of the produced threaded steel is Φ8mm, the 18# rolling mill in the pre-finish rolling unit is controlled so that the tolerance diameter range after rolling is 19.3mm-19.7mm (for example: 19.3mm, 19.5mm, 19.7mm, etc.), and the out-of-roundness is ≤0.4mm; the 4 rolling mills in the BGV unit are controlled to roll for 4 passes, and the tolerance diameter range after rolling is 12.4mm-12.7mm (for example: 12.4mm, 12.5mm, 12.7mm, etc.), and the out-of-roundness is ≤0.25mm; and the temperature of the head of the rolled piece entering the BGV unit is controlled to be ≥960℃, and the temperature of the head of the rolled piece entering the reducing sizing unit is controlled to be ≥950℃; the depth of the cross rib of the finished ring after rolling of the 30# rolling mill is 0.7mm.

[0057] Optionally, when rolling with the BGV unit, the 19#-22# rolling mills can be used.

[0058] Further, when the specification of the produced threaded steel is Φ8mm, the rough rolling temperature is 950-1000℃ (for example: 950℃, 980℃, 1000℃, etc.), the finish rolling temperature is 955-985℃ (for example: 955℃, 970℃, 985℃, etc.); the rolling speed of the 18# rolling mill is 16.09m / s, the rolling speed of the 22# rolling mill in the BGV unit is 39.43m / s, the rolling speed of the former stage of the reducing sizing unit is 57.18m / s, and the rolling speed of the later stage is 91.5m / s.

[0059] When the specification of the produced threaded steel is Φ10mm, the 18# rolling mill in the pre-finish rolling unit is controlled so that the tolerance diameter range after rolling is 19.3mm-19.7mm (for example: 19.3mm, 19.5mm, 19.7mm, etc.), and the out-of-roundness is ≤0.4mm; the 2 rolling mills in the BGV unit are controlled to roll for 2 passes, and the tolerance diameter range after rolling is 15.6mm-16.0mm (for example: 15.6mm, 15.8mm, 16.0mm, etc.), and the out-of-roundness is ≤0.3mm; and the temperature of the head of the rolled piece entering the BGV unit is controlled to be ≥940℃, and the temperature of the head of the rolled piece entering the reducing sizing unit is controlled to be ≥930℃; the depth of the cross rib of the finished ring after rolling of the 30# rolling mill is 0.9mm.

[0060] Optionally, when rolling with the BGV unit, 19-20 rolling mills can be used.

[0061] Further, when the specification of the produced threaded steel is Φ10mm, the opening rolling temperature is 950-1000℃ (for example, 950℃, 980℃, 1000℃, etc.), the final rolling temperature is 955-985℃ (for example, 955℃, 970℃, 985℃, etc.); the rolling speed of the 18 rolling mill is 16.38m / s, the rolling speed of the 20 rolling mill in the BGV unit is 24.5m / s, the rolling speed of the former stage of the reducing sizing unit is 36.6m / s, and the rolling speed of the later stage is 58.6m / s.

[0062] When the specification of the produced threaded steel is Φ12mm, the 18 rolling mill in the pre-precision rolling unit is controlled to make the tolerance diameter range of the rolled product be 19.3-19.7mm (for example, 19.3mm, 19.5mm, 19.7mm, etc.), and the out-of-roundness be ≤0.4mm; the two rolling mills in the BGV unit are controlled to roll for two passes, and make the tolerance diameter range of the rolled product be 15.6mm-16.0mm (for example, 15.6mm, 15.8mm, 16.0mm, etc.), and the out-of-roundness be ≤0.3mm; and the temperature of the head of the rolled piece entering the BGV unit is controlled to be ≥940℃, and the temperature of the head of the rolled piece entering the reducing sizing unit is controlled to be ≥930℃; the depth of the cross rib of the finished product roll ring rolled by the 30 rolling mill is 1.1mm.

[0063] Optionally, when rolling with the BGV unit, 19-20 rolling mills can be used.

[0064] Further, when the specification of the produced threaded steel is Φ12mm, the opening rolling temperature is 950-1000℃ (for example, 950℃, 980℃, 1000℃, etc.), the final rolling temperature is 875-905℃ (for example, 875℃, 890℃, 905℃, etc.); the rolling speed of the 18 rolling mill is 15.93m / s, the rolling speed of the 20 rolling mill in the BGV unit is 23.9m / s, the rolling speed of the former stage of the reducing sizing unit is 30.83m / s, and the rolling speed of the later stage is 40.7m / s.

[0065] The pre-precision rolling unit and the BGV unit are controlled for threaded steels of various specifications to realize control of different process sizes, which can effectively avoid the problem that the head of the rolled piece is too large to intensify the deformation of the steel head after the finished product roll is pressed in, so as to further improve the problem of the finished product punch outlet. Moreover, strict control of the tolerance size can avoid serious overage phenomenon, which can also further improve the problem of the finished product punch outlet.

[0066] No matter which specification of screw steel is produced, when the last pass is used, the depth of the finished product roll ring transverse rib is controlled to ensure easy steel removal after rolling, thereby further reducing the occurrence of head bending.

[0067] It should be noted that a diameter gauge is arranged after the No. 18 rolling mill of the pre-finishing rolling mill group and the No. 26 rolling mill of the BGV mill group to facilitate real-time detection of the diameter tolerance value after rolling.

[0068] It should be further noted that the opening rolling temperature, finishing rolling temperature and rolling speed are controlled for different specifications of screw steel to improve the strength and toughness of each specification of screw steel.

[0069] In the related art, the head (steel head) of the rolled piece is first cooled and the cooling is most obvious during the rolling process. If the temperature of the rolled piece is controlled by the water tank, forced water penetration is adopted throughout the process, which intensifies the cooling of the steel head. When the temperature is lower than the rolling load force (the module rolling capacity is greater than or equal to 750 DEG C), equipment failure occurs. In the present application, the head of the rolled piece does not penetrate water when the water tank is used for cooling control. The length of the head of the rolled piece that does not penetrate water is controlled to the required length by means of heat detection before entering the water tank and controlling the rolling speed before entering the water tank. Thus, the temperature of the head of the rolled piece is ensured, and the upper and lower deformations of the rolled piece are stable when the rolled piece bites into the No. 30 rolling mill. Only in this way, the rolled piece can be in a flat state when it exits the No. 30 rolling mill, and the head does not bend and rush out. Although the temperature control of each section has no direct effect on the rush-out of the No. 30 rolling mill, unreasonable control of the non-cooling section of the water tank will affect the rush-out of the No. 30 rolling mill. Moreover, since the present application is high-speed wire rod rolling, controlled rolling and controlled cooling rolling can be adopted to improve the organization and performance of the steel. Therefore, the opening rolling temperature and the process temperature can be determined according to different specifications of screw steel, and the controlled rolling and controlled cooling are achieved by the water tank to achieve the required product organization and performance.

[0070] When the high-speed wire rod is rolled at a speed of more than 15 m / s, the rolled piece will be heated. The faster the speed, the higher the temperature rise. In order to control the temperature of the rolled piece corresponding to each rack, the cooling water amount of the water tank in front of the rack needs to be adjusted to achieve the corresponding cooling. The head of the rolled piece does not need to pass through the water tank for cooling. For example, when the specification of the screw steel is Φ6 mm, the temperature of the head of the rolled piece entering the reducing and sizing mill group is controlled to be greater than or equal to 950 DEG C. The third water tank and the fourth water tank corresponding to the head of the rolled piece are removed, and then the cooling is started to avoid the head of the rolled piece forcibly penetrating the corresponding water tank for cooling, which causes the temperature of the head of the rolled piece to be much lower than 950 DEG C. Only when the head of the rolled piece is not cooled and the high temperature of the head of the rolled piece is ensured, can the subsequent rolling be stable.

[0071] In order to ensure the normal production of the rough rolling mill group, the medium rolling mill group, the pre-precision rolling mill group, the BGV mill group and the reducing and sizing mill group, and the stability of the tension, the metal volume of the rolled piece per second passing through each mill group needs to be equal, that is, the principle of equal metal second flow in the continuous rolling mill group needs to be met, and if the second flow between the racks is seriously inconsistent, the steel will be pulled and stacked between the mill groups, and the process accident of breaking or stacking between the mill groups will be caused, so the method can ensure excellent rolling quality and avoid the occurrence of process accidents by adopting different rolling speeds for different specifications of the threaded steel.

[0072] In order to prevent the threaded steel finished product from being punched out, the outlet diameter of each specification of the finished product (that is, the diameter of the outlet guide hole) needs to be reasonably selected, wherein when the specification of the threaded steel is Φ6mm, the maximum diameter of the threaded finished product is 7.9mm according to the national standard, and the outlet guide hole with a diameter of 14mm can be selected; when the specification of the threaded steel is Φ8mm, the maximum diameter of the threaded finished product is 10.5mm according to the national standard, and the outlet guide hole with a diameter of 18mm can be selected; when the specification of the threaded steel is Φ10mm, the maximum diameter of the threaded finished product is 12.8mm according to the national standard, and the outlet guide hole with a diameter of 22mm can be selected; and when the specification of the threaded steel is Φ15.1mm, the maximum diameter of the threaded finished product is 25mm according to the national standard, and the outlet guide hole with a diameter of 14mm can be selected.

[0073] Example 1

[0074] The opening rolling temperature is 950℃, and the final rolling temperature is 925℃.

[0075] The billet is rolled by the No.1-No.6 rolling mills of the rough rolling mill group.

[0076] The No.7-No.12 rolling mills of the medium rolling mill group are rolled.

[0077] The No.13-No.18 rolling mills of the pre-precision rolling mill group are rolled, the specification of the threaded steel produced is Φ6mm, the No.18 rolling mill in the pre-precision rolling mill group is controlled, the speed of the No.18 rolling mill is 10.51m / s, so that the tolerance diameter range after rolling is 19.3mm, and the out-of-roundness is ≤0.4mm; after rolling through the pre-precision rolling mill group, the first water tank and the second water tank are used for cooling; wherein when the first water tank is used for cooling, the part of the steel head with a length of 15cm is not cooled, when the second water tank is used for cooling, the part of the steel head with a length of 12cm is not cooled, and the temperature of the head of the rolled piece entering the BGV mill group is controlled to be ≥960℃.

[0078] The 19th-26th rolling mills of the BGV mill train are rolled by 8 passes, the rolling speed of the 26th rolling mill is 63.1 m / s, the tolerance diameter range after rolling is 7.8 mm, and the out-of-roundness is ≤0.25 mm; and after passing through the BGV mill train, the third water tank and the fourth water tank are used for cooling, wherein, when the third water tank is used for cooling, the part of the steel head with a length of 15 cm is not cooled, when the fourth water tank is used for cooling, the part of the steel head with a length of 12 cm is not cooled, and the temperature of the head of the rolled piece entering the reducing and sizing mill train is controlled to be ≥950℃.

[0079] The 27th-30th rolling mills of the reducing and sizing mill train are rolled, the speed of the 27th and 28th rolling mills is 80.7 m / s, and the speed of the 29th and 30th rolling mills is 105 m / s; wherein, when the 30th rolling mill is used for rolling, the upper and lower roll horizontal rib tooth edges are marked before the roll ring is installed, and the mark is extended to the end face of the roll, and when the marked roll ring is installed, the marks of the upper and lower rolls are aligned. The depth of the horizontal rib of the finished roll ring after rolling of the 30th rolling mill is 0.6 mm.

[0080] Example 2

[0081] The opening rolling temperature is 1000℃, and the finish rolling temperature is 955℃.

[0082] The billet is rolled by the 1st-6th rolling mills of the rough rolling mill train.

[0083] The 7th-12th rolling mills of the intermediate rolling mill train are rolled.

[0084] The 13th-18th rolling mills of the pre-finishing rolling mill train are rolled, and the specification of the deformed steel bar produced is Φ8 mm, the 18th rolling mill in the pre-finishing rolling mill train is controlled, the speed of the 18th rolling mill is 16.09 m / s, so that the tolerance diameter range after rolling is 19.7 mm, and the out-of-roundness is ≤0.4 mm; after rolling through the pre-finishing rolling mill train, the first water tank and the second water tank are used for cooling; wherein, when the first water tank is used for cooling, the part of the steel head with a length of 18 cm is not cooled, when the second water tank is used for cooling, the part of the steel head with a length of 15 cm is not cooled, and the temperature of the head of the rolled piece entering the BGV mill train is controlled to be ≥960℃.

[0085] The 19th-22nd rolling mills of the BGV mill train are rolled by 4 passes, the rolling speed of the 22nd rolling mill is 39.43 m / s, the tolerance diameter range after rolling is 12.4 mm, and the out-of-roundness is ≤0.25 mm; and after passing through the BGV mill train, the third water tank and the fourth water tank are used for cooling, wherein, when the third water tank is used for cooling, the part of the steel head with a length of 18 cm is not cooled, when the fourth water tank is used for cooling, the part of the steel head with a length of 15 cm is not cooled, and the temperature of the head of the rolled piece entering the reducing and sizing mill train is controlled to be ≥950℃.

[0086] The 27th-30th rolling mills of the reducing and sizing mill group are rolled, the speed of the 27th and 28th rolling mills is 57.18 m / s, and the speed of the 29th and 30th rolling mills is 91.5 m / s; wherein, when the 30th rolling mill is used for rolling, before the installation of the roller ring, the marks are made on the tooth edges of the upper and lower rollers, and the marks are extended to the end faces of the rollers, and when the marked roller ring is installed, the marks of the upper and lower rollers are aligned. The depth of the horizontal rib of the finished product roller ring after the rolling of the 30th rolling mill is 0.7 mm.

[0087] Example 3

[0088] The open rolling temperature is 1000℃, and the finish rolling temperature is 985℃.

[0089] The billet is rolled by the 1st-6th rolling mills of the rough rolling mill group.

[0090] The 7th-12th rolling mills of the intermediate rolling mill group are rolled.

[0091] The 13th-18th rolling mills of the pre-finishing rolling mill group are rolled, and the specification of the threaded steel produced is Φ10 mm, the 18th rolling mill in the pre-finishing rolling mill group is controlled, the speed of the 18th rolling mill is 16.38 m / s, so that the tolerance diameter range after rolling is 19.5 mm, and the out-of-roundness is ≤0.4 mm; after rolling through the pre-finishing rolling mill group, cooling is carried out by using the first water tank and the second water tank; wherein, when the first water tank is used for cooling, the part of the steel head with a length of 16 cm is not cooled, when the second water tank is used for cooling, the part of the steel head with a length of 13 cm is not cooled, and the temperature of the head of the rolled piece entering the BGV mill group is controlled to be ≥940℃.

[0092] The 19th-22nd rolling mills of the BGV mill group are rolled in 2 passes, the rolling speed of the 20th rolling mill is 24.5 m / s, the tolerance diameter range after rolling is 16.0 mm, and the out-of-roundness is ≤0.3 mm; and after passing through the BGV mill group, cooling is carried out by using the third water tank and the fourth water tank, wherein, when the third water tank is used for cooling, the part of the steel head with a length of 16 cm is not cooled, when the fourth water tank is used for cooling, the part of the steel head with a length of 14 cm is not cooled, and the temperature of the head of the rolled piece entering the reducing and sizing mill group is controlled to be ≥930℃.

[0093] The 27th-30th rolling mills of the reducing and sizing mill group are rolled, the speed of the 27th and 28th rolling mills is 36.6 m / s, and the speed of the 29th and 30th rolling mills is 58.6 m / s; wherein, when the 30th rolling mill is used for rolling, before the installation of the roller ring, the marks are made on the tooth edges of the upper and lower rollers, and the marks are extended to the end faces of the rollers, and when the marked roller ring is installed, the marks of the upper and lower rollers are aligned. The depth of the horizontal rib of the finished product roller ring after the rolling of the 30th rolling mill is 0.9 mm.

[0094] Example 4

[0095] The open rolling temperature is 960℃, and the finish rolling temperature is 905℃.

[0096] The blank is rolled by No. 1-No. 6 rolling mills of a rough rolling mill set.

[0097] No. 7-No. 12 rolling mills of a medium rolling mill set are rolled.

[0098] No. 13-No. 18 rolling mills of a pre-finishing rolling mill set are rolled, and the specification of the produced threaded steel is Φ12mm. The speed of No. 18 rolling mill in the pre-finishing rolling mill set is 15.93m / s, so that the tolerance diameter range after rolling is 19.6mm, and the out-of-roundness is ≤0.4mm. After rolling through the pre-finishing rolling mill set, the first water tank and the second water tank are used for cooling. When the first water tank is used for cooling, the part of the steel head with a length of 17cm is not cooled. When the second water tank is used for cooling, the part of the steel head with a length of 14cm is not cooled. The temperature of the head of the rolled piece entering the BGV mill set is controlled to be ≥940℃.

[0099] No. 19-No. 22 rolling mills of the BGV mill set are rolled in two passes. The rolling speed of No. 20 rolling mill is 23.9m / s, and the tolerance diameter range after rolling is 15.8mm, and the out-of-roundness is ≤0.3mm. After rolling through the BGV mill set, the third water tank and the fourth water tank are used for cooling. When the third water tank is used for cooling, the part of the steel head with a length of 15cm is not cooled. When the fourth water tank is used for cooling, the part of the steel head with a length of 13cm is not cooled. The temperature of the head of the rolled piece entering the reducing and sizing mill set is controlled to be ≥930℃.

[0100] No. 27-No. 30 rolling mills of the reducing and sizing mill set are rolled. The speed of No. 27 and No. 28 rolling mills is 30.83m / s, and the speed of No. 29 and No. 30 rolling mills is 40.7m / s. When No. 30 rolling mill is used for rolling, before the installation of the rolling ring, the marks are made on the upper and lower rolling mill horizontal rib tooth edges and extended to the end surface of the rolling, and when the marked rolling ring is installed, the marks of the upper and lower rolling are aligned. The depth of the horizontal rib of the finished rolling ring of No. 30 rolling mill is 1.1mm.

[0101] Comparative Example 1

[0102] The difference between Comparative Example 1 and Example 1 is that when the first water tank, the second water tank, the third water tank and the fourth water tank are used for cooling, the whole rolled piece is cooled, i.e. the steel head is also cooled.

[0103] Comparative Example 2

[0104] The difference between Comparative Example 2 and Example 1 is that when the first water tank and the second water tank are used for cooling, the whole rolled piece is cooled, i.e. the steel head is also cooled, i.e. the non-cooling section of the steel head of the rolled piece cooled by the first water tank and the second water tank is 0. Moreover, when the third water tank and the fourth water tank are used for cooling the rolled piece, the part of the head of the rolled piece with a length less than 8cm is not cooled, i.e. the non-cooling section of the rolled piece is less than 8cm.

[0105] Comparative Example 3

[0106] The difference between Comparative Example 3 and Example 1 is that the whole rolled piece is cooled, i.e. the steel head is also cooled, when cooled by the third water tank and the fourth water tank.

[0107] Comparative Example 4

[0108] The difference between Comparative Example 4 and Example 1 is that the whole rolled piece is cooled, i.e. the steel head is also cooled, when cooled by the first water tank and the third water tank.

[0109] Comparative Example 5

[0110] The difference between Comparative Example 5 and Example 1 is that the whole rolled piece is cooled, i.e. the steel head is also cooled, when cooled by the second water tank and the fourth water tank.

[0111] Examples 1-4 all improve the phenomenon of the finished product being punched out, but Comparative Examples 1-5 all have different degrees of the phenomenon of the finished product being punched out; among them, Figure 3 is the temperature curve of each steel in Example 1, Figure 4 is the temperature curve of each steel in Comparative Example 2, according to the temperature curve, the temperature difference of Example 1 is smaller than that of Comparative Example 2, which can ensure that Example 1 will not be punched out, but Comparative Example 2 will be punched out.

[0112] In summary, the method for preventing the finished high-line deformed steel bar from being punched out can improve the problem of the finished deformed steel bar being punched out, so as to ensure that the production of the deformed steel bar can be stably carried out.

[0113] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any change or replacement that can be easily thought of by those skilled in the art within the technical range disclosed by the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preventing high-line threaded steel finished product from being discharged, characterized in that, The application relates to a method for rolling a blank into a threaded steel bar. The blank is rolled by a rough rolling mill set, a medium rolling mill set, a pre-precision rolling mill set, a BGV mill set and a reducing sizing mill set in sequence; the rough rolling mill set comprises No.1-No.6 rolling mills, the medium rolling mill set comprises No.7-No.12 rolling mills, the pre-precision rolling mill set comprises No.13-No.18 rolling mills, the BGV mill set comprises No.19-No.26 rolling mills, and the reducing sizing mill set comprises No.27-No.30 rolling mills; wherein, After rolling by the pre-precision rolling mill set, the blank is cooled by a first water tank and a second water tank; and after rolling by the BGV mill set, the blank is cooled by a third water tank and a fourth water tank; When the blank is cooled by the first water tank, the steel head with a length of 15-18 cm is not cooled; When the blank is cooled by the second water tank, the steel head with a length of 12-15 cm is not cooled; When the blank is cooled by the third water tank, the steel head with a length of 15-18 cm is not cooled; When the blank is cooled by the fourth water tank, the steel head with a length of 12-15 cm is not cooled; The step of rolling by the No.30 rolling mill comprises the following steps: before the rolling ring is installed, marking is made on the rib tooth edge of the upper and lower rollers and the marking is extended to the end surface of the roller, and when the rolling ring with the marking is installed, the marking of the upper and lower rollers is aligned.

2. The method for preventing high-line screw steel finished product from being discharged according to claim 1, characterized in that, The blank is rolled by a rough rolling mill set, a medium rolling mill set, a pre-precision rolling mill set, a BGV mill set and a reducing sizing mill set in sequence, and the method further comprises the following steps: When the threaded steel bar with a specification of Phi 6 mm is produced, the No.18 rolling mill in the pre-precision rolling mill set is controlled so that the tolerance diameter range after rolling is 19.3 mm-19.7 mm and the out-of-roundness is less than or equal to 0.4 mm; the No.19-No.26 rolling mills in the BGV mill set are controlled to roll for 8 passes and so that the tolerance diameter range after rolling is 7.8 mm-8.1 mm and the out-of-roundness is less than or equal to 0.25 mm; the temperature of the head of the rolled piece entering the BGV mill set is greater than or equal to 960 DEG C, the temperature of the head of the rolled piece entering the reducing sizing mill set is greater than or equal to 950 DEG C; and the depth of the rib of the finished product rolling ring of the No.30 rolling mill is 0.6 mm.

3. The method for preventing high-line screw steel finished product from being discharged according to claim 2, characterized in that, When the threaded steel bar with a specification of Phi 6 mm is produced, the opening rolling temperature is 950-1000 DEG C and the final rolling temperature is 925-955 DEG C; The rolling speed of the No.18 rolling mill is 10.51 m / s, the rolling speed of the No.26 rolling mill in the BGV mill set is 63.1 m / s, and the rolling speed of the reducing sizing mill set is 80.7 m / s in the early stage and 105 m / s in the later stage.

4. The method for preventing high-line screw steel finished product from being discharged according to claim 1, characterized in that, The blank is rolled by a rough rolling mill set, a medium rolling mill set, a pre-precision rolling mill set, a BGV mill set and a reducing sizing mill set in sequence, and the method further comprises the following steps: When the specification of the produced threaded steel is Φ8mm, the No.18 rolling mill in the pre-finishing rolling mill group is controlled to make the tolerance diameter range of the rolled product 19.3mm-19.7mm, and the out-of-roundness ≤0.4mm; the four rolling mills in the BGV mill group are controlled to roll for four passes, and the tolerance diameter range of the rolled product is 12.4mm-12.7mm, and the out-of-roundness ≤0.25mm; and the temperature of the head of the rolled piece entering the BGV mill group is ≥960℃, and the temperature of the head of the rolled piece entering the reducing and sizing mill group is ≥950℃; the depth of the cross rib of the finished product roll ring rolled by the No.30 rolling mill is 0.7mm.

5. The method for preventing high-line screw steel finished product from being discharged according to claim 4, characterized in that, When the specification of the produced threaded steel is Φ8mm, the starting rolling temperature is 950-1000℃, and the final rolling temperature is 955-985℃; The rolling speed of the No.18 rolling mill is 16.09m / s, the rolling speed of the No.22 rolling mill in the BGV mill group is 39.43m / s, and the rolling speed of the reducing and sizing mill group is 57.18m / s in the early stage and 91.5m / s in the later stage.

6. The method for preventing high-line screw steel finished product from being discharged according to claim 1, characterized in that, The blank is rolled by the rough rolling mill group, the medium rolling mill group, the pre-finishing rolling mill group, the BGV mill group and the reducing and sizing mill group in sequence, and specifically further comprising: When the specification of the produced threaded steel is Φ10mm, the No.18 rolling mill in the pre-finishing rolling mill group is controlled to make the tolerance diameter range of the rolled product 19.3mm-19.7mm, and the out-of-roundness ≤0.4mm; the two rolling mills in the BGV mill group are controlled to roll for two passes, and the tolerance diameter range of the rolled product is 15.6mm-16.0mm, and the out-of-roundness ≤0.3mm; and the temperature of the head of the rolled piece entering the BGV mill group is ≥940℃, and the temperature of the head of the rolled piece entering the reducing and sizing mill group is ≥930℃; the depth of the cross rib of the finished product roll ring rolled by the No.30 rolling mill is 0.9mm.

7. The method for preventing high-line screw steel finished product from being discharged according to claim 6, characterized in that, When the specification of the produced threaded steel is Φ10mm, the starting rolling temperature is 950-1000℃, and the final rolling temperature is 955-985℃; The rolling speed of the No.18 rolling mill is 16.38m / s, the rolling speed of the No.20 rolling mill in the BGV mill group is 24.5m / s, and the rolling speed of the reducing and sizing mill group is 36.6m / s in the early stage and 58.6m / s in the later stage.

8. The method for preventing high-line screw steel finished product from being discharged according to claim 1, characterized in that, The blank is rolled by the rough rolling mill group, the medium rolling mill group, the pre-finishing rolling mill group, the BGV mill group and the reducing and sizing mill group in sequence, and specifically further comprising: When the specification of the produced threaded steel is Φ12mm, the No.18 rolling mill in the pre-finishing rolling mill group is controlled to make the tolerance diameter range of the rolled product 19.3-19.7mm, and the out-of-roundness ≤0.4mm; the two rolling mills in the BGV mill group are controlled to roll for two passes, and the tolerance diameter range of the rolled product is 15.6mm-16.0mm, and the out-of-roundness ≤0.3mm; and the temperature of the head of the rolled piece entering the BGV mill group is ≥940℃, and the temperature of the head of the rolled piece entering the reducing and sizing mill group is ≥930℃; the depth of the cross rib of the finished product roll ring rolled by the No.30 rolling mill is 1.1mm.

9. The method for preventing high-line screw steel finished product from being discharged according to claim 8, characterized in that, When the specification of the produced screw steel is Φ12mm, the opening rolling temperature is 950-1000℃, and the final rolling temperature is 875-905℃; The rolling speed of the 18# rolling mill is 15.93m / s, the rolling speed of the 20# rolling mill in the BGV mill set is 23.9m / s, the rolling speed of the former stage of the reducing mill set is 30.83m / s, and the rolling speed of the later stage is 40.7m / s.

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