An improved apparatus for the fractional quenching of molten metal

Abstract

The application relates to an improved molten metal grading quenching device, which comprises a chassis and a melting furnace arranged on the chassis, characterized in that an inlet is arranged at the front end of the chassis, an outlet is arranged at the rear end of the chassis, and an outlet sealing structure is arranged at the outlet; the melting furnace is arranged at the front end of the chassis and is communicated with the inlet, a workpiece channel is formed at the upper portion of the melting furnace, a cooling system and a pressing mechanism are sequentially arranged above the workpiece channel in the workpiece advancing direction, an air cooling structure and a water cooling structure are arranged below the workpiece channel close to the inlet, and a molten primary quenching structure is formed; a pressing adjusting mechanism, an outlet box, a phase change control structure, a water cooling jacket and the outlet sealing structure are sequentially arranged at the rear portion of the chassis in the workpiece advancing direction, a secondary quenching structure is formed at the water cooling jacket or at a flattening air cooling section; a control output end of a control system is connected with a PLC control control system, and the molten metal grading quenching device is formed. The device has the characteristics of simple structure, small volume, light weight and low price.

Description

TECHNICAL FIELD

[0001] The present application relates to an improved molten metal fractional quenching device, which is suitable for the tempering treatment of steel strip. It belongs to the technical field of metal heat treatment equipment. BACKGROUND

[0002] With the rapid development of the domestic tool field, the demand for steel strip is increasing, and the quality requirements are also increasing. The quality requirements for steel strip mainly include the consistency of the product metallographic structure, the uniformity of hardness, the flatness precision of the plate surface, and the requirements of fatigue resistance and temper resistance.

[0003] At present, in order to make the quality of steel strip products meet the requirements of the consistency of the metallographic structure, the uniformity of the hardness, the flatness precision of the plate surface, and the requirements of fatigue resistance and temper resistance, the domestic main fractional quenching process using nitrate as medium is adopted. However, the nitrate quenching process has the problems of secondary pollution, difficult control of water and environmental pollution. Although some people in western developed industrial countries have adopted molten metal fractional quenching process to achieve the quality requirements of steel strip products, due to the problems of complex structure, large volume, heavy weight and high price of the involved equipment, it is not suitable for popularization and use in China. Although some people in China have manufactured molten metal fractional quenching equipment referring to foreign equipment, and have used it tentatively for the manufacture of low-end products of wood narrow saw blade, due to the defects, it cannot be used for quenching treatment of wide and thick steel strip. SUMMARY

[0004] The purpose of the present application is to solve the problems of complex structure, large volume, heavy weight and high price of the existing molten metal fractional quenching equipment, and to provide an improved molten metal fractional quenching device. It has the outstanding substantial features and significant technical progress of simple structure, small volume, light weight and low price.

[0005] The purpose of the present application can be achieved by adopting the following technical solutions:

[0006] An improved molten metal grading quenching device, comprising a chassis and a melting furnace arranged on the chassis, and characterized in that: an inlet is arranged at the front end of the chassis, an outlet is arranged at the rear end of the chassis, and an outlet sealing structure is arranged at the outlet; the melting furnace is arranged at the front end of the chassis and communicates with the inlet, a workpiece channel is formed at the upper part of the melting furnace, a cooling system and a pressing mechanism are arranged in sequence above the workpiece channel along the workpiece advancing direction, and a forced air cooling structure and a water cooling structure are arranged below the workpiece channel close to the inlet, forming a molten primary quenching structure; a pressing adjusting mechanism, an outlet box, a phase change control structure, a water cooling jacket and an outlet sealing structure are arranged in sequence along the workpiece advancing direction at the rear part of the chassis, the pressing adjusting mechanism, the outlet box and the phase change control structure constitute a flattening forced air cooling section, and a secondary quenching structure is formed at the water cooling jacket or at the flattening forced air cooling section; the control ends of the cooling system, the pressing mechanism, the pressing adjusting mechanism, the phase change control structure, the water cooling structure and the forced air cooling structure of the molten primary quenching structure are connected with the control output ends of a PLC control system, forming a molten metal grading quenching device.

[0007] The object of the present application can also be achieved by adopting the following technical solutions:

[0008] Further, an asbestos fiber support structure is arranged at the inlet, and the asbestos fiber support structure is composed of an upper arc plate, a lower arc plate, a bottom plate and a fiber felt; a handle is welded on the upper arc plate, a sliding block is arranged on the lower arc plate, a sliding groove is opened on the bottom plate, the bottom plate is connected with the melting pool through screws, the fiber felt is clamped between the upper arc plate and the lower arc plate, and the upper arc plate and the lower arc plate are connected into an integrated body through screws.

[0009] Further, the forced air cooling structure is arranged at the inner recessed cavity of the melting furnace, forming a forced air cooling structure at the inlet end of the workpiece channel; the forced air cooling structure comprises a heat dissipation grid and an air inlet and an air outlet of the inner recessed cavity, the heat dissipation grid is located in the inner recessed cavity and communicates with the air inlet and the air outlet, so that cold air is blown into the air inlet and hot air is discharged from the air outlet, and the molten metal liquid is separated from the outside through the inner recessed cavity, forming a heat exchange structure. In actual application, the heat dissipation grid has a large heat exchange area, and a frequency conversion fan blows in appropriate air volume according to system setting to achieve the purpose of heat exchange.

[0010] Further, the water cooling structure is arranged at the lower side of the workpiece channel at the inlet, forming a water cooling structure at the inlet end of the workpiece channel; comprising a water inlet pipe, a heat exchange device and a water outlet pipe, the heat exchange device is a tubular structure, comprising an inner tube and an outer cooling tube, an intermediate tube is arranged between the inner tube and the outer cooling tube, an intermediate small tube is arranged in the inner cavity of the inner tube, a plurality of damping plugs and water distribution plates are arranged in the intermediate small tube, the two ends of the inner tube are respectively communicated with the water inlet pipe and the water outlet pipe, the intermediate small tube is fixedly connected to the inner wall of the inner tube through the water distribution plate, and the water inlet of the intermediate small tube is communicated with the inner tube; the water distribution plate is in the shape of "U", and the inner cavity thereof is communicated with the inner cavity of the intermediate small tube; the cooling water enters the intermediate small tube from the inner tube after entering the inner tube, and is uniformly sprayed to the water distribution plate along the axial direction of the tube through the plurality of damping plugs, and is sprayed to the heated surface of the inner tube through the guide grooves of the water distribution plate, forming a water heat exchange structure.

[0011] Further, in the water cooling structure, a heat-conducting medium is filled between the outer cooling tube and the intermediate tube to effectively control the linear relationship degree of heat taken away by water, and through the conduction of the heat-conducting medium, the phenomenon of solidification of molten metal due to rapid cooling caused by direct heat exchange between water and the outer cooling tube is reduced, so that the temperature is controllable.

[0012] Further, the lower pressing mechanism is a gantry structure, comprising a gantry and a sliding frame, a sliding groove structure is arranged on each of the two inner sides of the gantry, a sliding block is arranged in the sliding groove structure, the two sides of the sliding frame are directly connected with the sliding blocks or connected with the sliding blocks through connecting plates, the upper end of the sliding frame is connected with the worm lifting mechanism, and the two sides of the sliding frame are positioned and connected with the gantry through screws, forming a positionable up-and-down sliding connection structure; the bottom surface of the sliding frame is connected with an arc plate structure for pressing the workpiece, forming a lower arched pressing mechanism; the gantry is arranged on the guide rail of the melting furnace and can move and position horizontally on the guide rail, and the gantry is locked by screws after positioning on the guide rail, forming a movable structure.

[0013] Further, the worm lifting mechanism comprises a motor, a shaft coupling, and two worm gear structures, the motor is fixed on the gantry, the output shaft of the motor is connected with the worm gear structures through the shaft coupling, and the two worm gear structures are connected through an intermediate transmission shaft to form a linkage structure; the sliding frame is synchronously raised / lowered through the worm lifting mechanism.

[0014] Further, a scale is arranged in the lower pressing mechanism, which is used to display the up-and-down adjustment and positioning position of the sliding frame of the lower pressing mechanism to adapt to different workpiece thicknesses; the sliding frame is locked by locking screws after adjustment; the arc plate structure of the lower pressing mechanism comprises an upper arc plate, a lower arc plate and a fiber felt sandwiched between the upper arc plate and the lower arc plate, and the upper arc plate is provided with a passage for quickly replacing the fiber felt and a pressing plate for pressing the felt.

[0015] Further, the outlet sealing structure is an L-shaped outlet sealing structure, comprising a frame body, a pair or more pairs of air cylinders arranged at the front end of the frame body, a pair or more pairs of cross beams arranged in the inner cavity of the frame body, and a sealing fiber layer arranged on each of the opposite surfaces of each pair of cross beams; the cross beams are arranged on the upper and lower sides of the workpiece channel to seal the workpiece, the front part of the cross beam is connected with the telescopic rod of the air cylinder, and the rear end is fixed on the rear inner wall of the frame body, so that the air cylinder pushes the cross beam to seal the contact surface between the workpiece and the frame body and the outlet water cooling jacket through the fiber layer, to prevent or reduce the leakage of the protective atmosphere, and ensure that the workpiece is bright and not oxidized.

[0016] Further, the outlet box comprises a box body, a box cover, a swing cylinder, a pressing cylinder, an inspection door, a scraper group, a heater, a wiper and a nitrogen pipe, a thermocouple and a heat preservation asbestos layer are arranged in the inner cavity of the box body; after the steel strip is discharged from the melting furnace, the medium left on the surface is scraped off by the wiper, then the swing cylinder and the pressing cylinder 904 jointly flatten the steel strip through the compression scraper group, and the residual medium is wiped clean by the asbestos felt arranged above the compression scraper group; the heater is used for supplementing the loss of heat, so that the steel strip will not be phase changed; the nitrogen pipe fills the heated nitrogen into the box to protect the brightness of the steel strip.

[0017] Further, the water cooling jacket comprises a jacket body, a water inlet pipe, a communication pipe, a water outlet pipe, a partition plate and a graphite block arranged in the jacket body, and the cavity of the jacket body is welded into four cavities by steel plates, which are used for cooling the outlet of the steel strip to increase the strength and hardness of the workpiece; the cooling water enters from the water inlet pipe, flows into one of the lower cavities, returns to the other lower cavity through the lower part of the partition plate, enters one of the upper cavities through the water outlet pipe, enters the other upper cavity through the upper part of the partition plate, and then flows into the pool through the water outlet pipe; the graphite block arranged in the water cooling jacket is used for supporting the steel strip.

[0018] Further, the pressing adjusting mechanism is fixed on the base frame and comprises a worm lifting machine, a shaft coupling, a transmission shaft, a hand wheel, a connecting rod and a pin shaft; when the pressing mechanism needs to be adjusted forward and backward according to the process requirement, the worm box connected by the transmission shaft and the shaft coupling is shaken by the hand wheel, the worm is driven by the worm gear to move forward and backward along the axial direction, and then the pin shaft and the connecting rod connected with the pin shaft are driven to move horizontally, the pressing mechanism and the connecting rod are connected through the pin shaft, and the pressing mechanism is locked after reaching the specified position as required.

[0019] Further, the phase change control structure comprises a phase change base plate, a heater, a frame body, a connecting screw and a thermocouple; the phase change base plate is arranged below the outlet box and on the bottom surface of the workpiece, and is used together with the heater at the upper part of the outlet box to control the temperature of the workpiece, so that the workpiece is kept in the supercooled austenite state; the heat output is detected by the thermocouple and then controlled by the program.

[0020] Further, an auxiliary cooling structure is arranged between the pressing mechanism and the outlet box, which comprises a mounting frame, one of the water pipes, the other water pipe, a transmission rod, a swing mechanism and a crank handle; the swing mechanism moves up, down, left and right in the waist-shaped sliding groove on the plate member to which the crank handle is fixed, so as to adjust the cooling position of the water pipes to the steel belt and achieve the desired process requirements.

[0021] Further, an electric heating structure is arranged in the melting furnace to heat the melting furnace; a furnace lining is arranged on the inner side wall of the melting furnace, and a dust hood is arranged on the surface of the melting furnace to prevent pollution.

[0022] The present application has the following outstanding substantial features and significant technical progress:

[0023] 1. The present application is provided with an inlet device at the front end of the chassis, an outlet device at the rear end, an outlet sealing structure at the outlet; a melting furnace is arranged at the front end of the chassis and communicates with the inlet, a workpiece passage is formed at the upper part of the melting furnace, a cooling system and a pressing mechanism are arranged above the workpiece passage in sequence along the workpiece advancing direction, a forced air cooling structure and a water cooling structure are arranged below the workpiece passage close to the inlet, forming a first-stage melting quenching structure; a pressing adjusting mechanism, an outlet box, a phase change and control structure, a water cooling jacket and an outlet sealing structure are arranged in sequence along the workpiece advancing direction at the rear part of the chassis, forming a second-stage quenching structure; the control ends of the cooling system, the pressing mechanism of the first-stage melting quenching structure and the pressing adjusting mechanism, the phase change and control structure, the water cooling structure and the forced air cooling structure of the second-stage quenching structure are connected with the control output ends of the PLC control system, forming a graded quenching structure of molten metal; therefore, the problems of complex structure, large size, heavy weight and high price of the existing graded quenching equipment of molten metal can be solved, and the present application has the outstanding substantial features and significant technical progress of simple structure, small size, light weight and low price.

[0024] 2. The water cooling structure is arranged below the inlet of the workpiece (steel belt), the cooling water enters the intermediate small pipe from the water inlet pipe, is uniformly sprayed to the water distribution plate by the intermediate small pipe along the axial direction of the pipe through the damping plugs, is sprayed to the heated surface through the flow guide groove of the water distribution plate due to the eccentricity between the intermediate pipe and the inner pipe, and the heat of the steel belt transferred to the molten metal is conducted to the intermediate pipe through the outer cooling pipe and the medium, and the water between the intermediate pipe and the inner pipe carries away the heat and flows out from the other end through the water outlet pipe; therefore, the present application has the characteristics of uniform cooling and good effect.

[0025] 3. The application has the scale in the lower pressing mechanism, which is used to show the position of the sliding frame of the lower pressing mechanism, so as to adapt to different workpiece thicknesses; the sliding frame is locked by the locking screw after adjustment; the arc plate structure of the lower pressing mechanism comprises an upper arc plate, a lower arc plate and a fiber felt clamped between the upper arc plate and the lower arc plate, and the upper arc plate is provided with a passage for quickly replacing the fiber felt and a pressing plate for pressing the felt; therefore, the application has the characteristics of being suitable for various different specifications of workpieces (steel strips) and wide application range.

[0026] 4. The application can integrate the grading quenching and tempering process of the steel strip, and the quenched material can be timely tempered to ensure good product organization and bright and smooth surface. The labor intensity of operation is reduced through automatic program control, and the quality is more guaranteed. Meanwhile, the medium is easy to obtain, and the main materials are low-melting-point metals, water, nitrogen and air, which are environmentally friendly.

[0027] 5. The application effectively solves the unevenness of the air jet on the cross section of the relative strip surface in the annealing slow cooling section, while ensuring more sufficient cooling in the width direction of the strip, thereby reducing the internal stress of the strip during cooling and obtaining good flatness. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a structure schematic view of the embodiment of the application.

[0029] Figure 2 It is a structure sectional view of the A-A direction of

[0030] Figure 3-1 It is a structure schematic view of the asbestos fiber structure of the embodiment of the application.

[0031] Figure 3-2 It is a structure front view of the asbestos fiber structure of the embodiment of the application.

[0032] Figure 3-3 It is a structure sectional view of the A-A direction of Figure 3-2

[0033] Figure 4 It is a structure schematic view of the air cooling structure of the embodiment of the application.

[0034] Figure 5-1 It is a structure schematic view of the water cooling structure of the embodiment of the application.

[0035] Figure 5-2 It is a structure front view of the water cooling structure of the embodiment of the application.

[0036] Figure 5-3 It is a structure sectional view of the B-B direction of Figure 5-2

[0037] Figure 6 ​​Structure schematic diagram of the down-pressing mechanism of the embodiment of the present application.

[0038] Figure 7 Structure schematic diagram of the outlet sealing of the embodiment of the present application.

[0039] Figure 8-1 Structure schematic diagram of the outlet box.

[0040] Figure 8-2 Structure schematic diagram of the outlet box. Figure 8-1 A-A sectional view of the outlet box.

[0041] Structure schematic diagram of the water cooling jacket.

[0042] Figure 9-2 B-B sectional view of the outlet box. Figure 9-1 B-B sectional view of the outlet box.

[0043] Figure 10 Structure schematic diagram of the down-pressing adjusting mechanism.

[0044] Figure 11-1 Structure sectional view of the phase change controller.

[0045] Figure 11-2 Structure schematic diagram of the phase change controller.

[0046] Figure 12 Structure schematic diagram of the auxiliary cooling device. DETAILED DESCRIPTION Embodiment 1

[0048] With reference to Figures 1 to 12 , the embodiment 1 comprises a base frame 8 and a melting furnace 15 arranged on the base frame, an inlet 1 is arranged at the front end of the base frame 8 and an outlet 2 is arranged at the rear end of the base frame 8, an outlet sealing structure 7 is arranged at the outlet 2; the melting furnace 15 is arranged at the front end of the base frame 8 and communicates with the inlet 1, a workpiece channel is formed at the upper part of the melting furnace 15, a cooling system 2 and a down-pressing mechanism 3 are arranged above the workpiece channel in sequence along the workpiece advancing direction, a forced air cooling structure 14 and a water cooling structure 13 are arranged below the workpiece channel close to the inlet 1, forming a melting primary quenching structure; a down-pressing adjusting mechanism 10, an outlet box 5, a phase change control structure 11, a water cooling jacket 6 and the outlet sealing structure 7 are arranged in sequence along the workpiece advancing direction at the rear part of the base frame 8, the down-pressing adjusting mechanism 10, the outlet box 5 and the phase change control structure 11 constitute a flattening forced air cooling section, a secondary quenching structure is formed at the water cooling jacket 6 or at the flattening forced air cooling section; the cooling system 2 of the melting primary quenching structure, the down-pressing mechanism 3, the down-pressing adjusting mechanism 10, the phase change control structure 11, the water cooling structure 13 and the control end of the forced air cooling structure 14 are connected with the control output end of a PLC control system respectively, forming a molten metal graded quenching device.

[0049] In the embodiment:

[0050] The asbestos fiber support structure is provided at the inlet 1 and is composed of an upper arc plate 101, a lower arc plate 102, a bottom plate 104 and a fiber felt 103; a handle is welded on the upper arc plate 101, a sliding block is provided on the lower arc plate 102, a sliding groove is opened on the bottom plate 104, the bottom plate 104 is connected with the molten pool through screws, and the fiber felt 103 is clamped between the upper arc plate 101 and the lower arc plate 102.

[0051] In actual application, when the fiber felt needs to be replaced due to wear, the asbestos fiber support structure is pulled out from the sliding groove after the steel belt is lifted by the cylinder pushing the connecting rod, and a new asbestos fiber support structure can be replaced.

[0052] The air cooling structure 14 is arranged at the inner recessed cavity of the melting furnace 15 to form an air cooling structure at the entrance end of the workpiece channel.

[0053] As preferred, the air cooling structure 14 includes a heat dissipation grid 202 and air inlets 201 and outlets 203 of the inner recessed cavity, the heat dissipation grid 202 is located in the inner recessed cavity and communicates with the air inlets 201 and the air outlets 203, so that the cold air is blown into the air inlets 201 and the hot air is discharged from the air outlets 203, and the metal molten liquid is separated from the outside through the inner recessed cavity to form a heat exchange structure. In actual application, the heat dissipation grid has a large heat exchange area, and the frequency conversion fan blows in a suitable air volume according to the system setting to achieve the purpose of heat exchange.

[0054] The water cooling structure 13 is arranged at the lower side of the workpiece channel at the inlet 1 to form a water cooling structure at the entrance end of the workpiece channel.

[0055] As preferred, the water cooling structure 13 can include a water inlet pipe 301, a heat exchange device and a water outlet pipe 309, the heat exchange device is a tubular structure and includes an inner pipe 308 and an outer cooling pipe 307, an intermediate pipe 305 is arranged between the inner pipe 308 and the outer cooling pipe 307, an intermediate small pipe 302 is arranged in the inner cavity of the inner pipe 308, a plurality of damping plugs 303 and water distribution plates 304 are arranged in the intermediate small pipe 302, the two ends of the inner pipe 308 are communicated with the water inlet pipe 301 and the water outlet pipe 309 respectively, the intermediate small pipe 302 is fixedly connected to the inner wall of the inner pipe 308 through the water distribution plates 304, and the water inlet of the intermediate small pipe 302 is communicated with the inner pipe 308; the water distribution plates 304 are in a "U" shape, and the inner cavities thereof are communicated with the inner cavities of the intermediate small pipe 302; the cooling water enters the inner pipe 308 from the water inlet pipe 301, enters the intermediate small pipe 302 and is uniformly sprayed to the water distribution plates 304 along the axial direction of the pipe through the plurality of damping plugs 303, and is sprayed to the heated surface of the inner pipe 308 through the flow guide grooves of the water distribution plates 304 to form a water heat exchange structure.

[0056] In particular, in the water cooling structure 13, a heat conductive medium 306 can be filled between the outer cooling pipe 307 and the intermediate pipe 305 to effectively control the linear relationship of the heat removal by water, and through the conduction of the heat conductive medium 306, the direct heat exchange between water and the outer cooling pipe 307 is reduced to avoid the phenomenon of rapid solidification of the molten metal caused by vaporization, so that the temperature can be controlled.

[0057] In actual application, the water cooling structure 13 is arranged below the entrance of the workpiece (steel strip), the cooling water enters the intermediate small pipe 302 from the water inlet pipe 301, and the water is uniformly sprayed to the water distribution plate 304 through the intermediate small pipe 302 along the axial direction of the pipe by the damping plugs 303. Since the intermediate pipe 305 is eccentric to the inner pipe 308, the water is sprayed to the heated surface through the guide groove of the water distribution plate 304, the heat of the steel strip transferred to the molten metal is conducted to the intermediate pipe 305 through the outer cooling pipe 307 and the medium 306, and the water between the intermediate pipe 305 and the inner pipe 308 removes the heat and flows out from the other end through the water outlet pipe 309.

[0058] It should be noted that the water cooling structure 13 and the air cooling structure 14 can be used simultaneously or separately. When the workpiece is a narrow and thin steel strip, the required heat exchange amount is small, and the air cooling structure 14 can be used for cooling. When the workpiece is a wide and thick steel strip, the required heat exchange amount is large, and the water cooling structure 13 or the water cooling structure 13 and the air cooling structure 14 are used for cooling.

[0059] As a preferred embodiment, the downward pressing mechanism 3 is a gantry structure, including a gantry 401 and a sliding frame 402, a sliding groove structure 405 is arranged on each of the two inner sides of the gantry 401, a sliding block 404 is arranged in the sliding groove structure 405, the two sides of the sliding frame 402 are directly connected with the sliding block 404 or connected with the sliding block 404 through a connecting plate 403, the upper end of the sliding frame 402 is connected with a worm lifting mechanism 408, and the two sides of the sliding frame 402 are positioned and connected with the gantry 401 through screws, forming a positionable upward and downward sliding connection structure; the bottom surface of the sliding frame 402 is connected with an arc plate structure 412 for pressing the workpiece, forming a downward arch-shaped downward pressing mechanism; the gantry 401 is arranged on the guide rail of the melting furnace 15 and can move and position horizontally on the guide rail, and the gantry 401 is locked by screws after positioning on the guide rail, forming a movable structure.

[0060] In particular, the worm lifting mechanism 408 includes a motor 406, a shaft coupling 407, and two worm gear structures, the motor 406 is fixed on the gantry 401, the output shaft of the motor 406 is connected with the worm gear structures through the shaft coupling 407, and the two worm gear structures are connected through an intermediate transmission shaft 409 to form a linkage structure; the sliding frame 402 is synchronously lifted and lowered through the worm lifting mechanism 408.

[0061] The outlet sealing structure 7 is an L-shaped outlet sealing structure, comprising a frame body 501, a pair or multiple pairs of air cylinders 502 arranged at the front end of the frame body 501, a pair or multiple pairs of cross beams 503 arranged in the inner cavity of the frame body 501, and a sealing fiber layer 504 arranged on each of the opposite surfaces of each pair of cross beams 503. The cross beams 503 are arranged on the upper and lower sides of the workpiece channel to seal the workpiece. The front part of the cross beam 503 is connected with the telescopic rod of the air cylinder 502, and the rear end is fixed on the rear inner wall of the frame body 501, so that the air cylinder 502 pushes the cross beam 503 to seal the contact surface between the workpiece and the frame body 501 and the outlet water cooling jacket through the sealing fiber layer 504, to prevent or reduce the leakage of the protective atmosphere, and ensure that the workpiece is bright and not oxidized.

[0062] The outlet box 5 comprises a box body 901, a box cover 902, a swing cylinder 903, a pressing cylinder 904, an inspection door 905, a scraper group 906, a heater 907, a wiper 908 and a nitrogen pipe 909. A thermocouple and a heat preservation asbestos layer are arranged in the inner cavity of the box body 901. After the steel strip is discharged from the melting furnace 15, the medium left on the surface is scraped off by the wiper 908, and then the swing cylinder 903 and the pressing cylinder 904 jointly press the steel strip through the pressing scraper group 906 to preliminarily flatten the steel strip and wipe off the residual medium by using the asbestos felt arranged above the pressing scraper group 906. The heater 907 is used to supplement the loss of heat, so that the steel strip will not be phase changed. The heated nitrogen is filled into the box through the nitrogen pipe 909 to protect the brightness of the steel strip.

[0063] The water cooling jacket 6 comprises a jacket body, an inlet pipe 801, a communication pipe 802, a water outlet pipe 803, a partition plate 804 and a graphite block 805 arranged in the jacket body. The cavity of the jacket body is welded by four cavities formed by steel plates, which are used to cool the outlet of the steel strip to increase the strength and hardness of the workpiece. The cooling water enters from the inlet pipe 801, flows into one of the lower cavities L1, returns to the other lower cavity L2 from the lower part of the partition plate 804, then enters one of the upper cavities L3 through the water outlet pipe 803, and then enters the other upper cavity L4 through the upper part of the partition plate 804, and finally flows into the pool through the water outlet pipe 803. The graphite block 805 is arranged in the water cooling jacket, which is used to support the steel strip.

[0064] The downward adjusting mechanism 10 is fixed on the base frame 8, and comprises a worm lifting machine 701, an adjusting coupling 702, a transmission shaft 703, a hand wheel 705, a connecting rod 704 and a pin shaft 706. When the downward mechanism 3 needs to be adjusted forward and backward according to the process requirement, the worm box connected by the transmission shaft and the coupling is shaken by the hand wheel 705, so that the worm is driven by the worm wheel to move forward and backward along the axial direction, and then the pin shaft 706 and the connecting rod 704 connected with the pin shaft 706 are driven to move horizontally. The downward mechanism is connected with the connecting rod 704 through the pin shaft, and the downward mechanism is locked after reaching the specified position as required.

[0065] The phase change controller 11 comprises a phase change base plate 601, a heating device 602, a phase change frame 603, a connecting screw 604 and a thermocouple 605; it is mainly used for temperature control of the steel strip together with the heater on the upper part of the outlet box to keep the steel strip in the supercooled austenite state. The heat output is detected by the thermocouple and then controlled by the program.

[0066] The embodiment 3 of the present application is characterized in that the melting furnace 15 is provided with an electric heating structure 9 for heating the melting furnace 15; the inner side wall of the melting furnace 15 is provided with a furnace lining 12, and the outer surface of the melting furnace 15 is provided with a dust hood to prevent pollution. Embodiment 2:

[0068] The embodiment 2 of the present application is characterized in that the lower pressing mechanism 3 is provided with a scale 411 for displaying the up and down adjustment position of the sliding frame 402 of the lower pressing mechanism 3 to adapt to different workpiece thicknesses; the sliding frame 402 is locked by the locking screw 410 after adjustment; the arc plate structure 412 of the lower pressing mechanism 3 comprises an upper arc plate, a lower arc plate and a fiber felt clamped between the upper arc plate and the lower arc plate, and is provided with a passage for quickly replacing the fiber felt and a pressing plate for pressing the felt. The rest is the same as embodiment 1. Embodiment 3:

[0070] The embodiment 3 of the present application is characterized in that the auxiliary cooling structure 4 is arranged between the lower pressing mechanism 3 and the outlet box 5, and the auxiliary cooling structure 4 comprises a mounting frame 1001, a water pipe 1002, a water pipe 1003, a transmission rod 1004, a swing mechanism 1005 and a rocking handle 1006; the mounting frame 1001 and the rocking handle 1006 are fixedly connected to a plate, a waist-shaped sliding groove is formed in the plate, the swing mechanism 1005 moves up and down and left and right in the waist-shaped sliding groove, so as to adjust the cooling position of the water pipe to the steel strip to meet the ideal process requirement. The rest is the same as embodiment 1.

[0071] In practical application, the related embodiments of the present application have the following advantages:

[0072] The asbestos fiber support structure 100 is a quick felt replacement structure, the upper arc plate 101 of the quick felt replacement structure is welded with a handle, the lower arc plate is provided with a sliding block, a sliding groove is formed in the bottom plate, and the bottom plate is connected with the melting furnace 15 by screws, and the upper arc plate and the lower arc plate clamp the fiber felt and are connected into a whole by screws.

[0073] When the fiber felt needs to be replaced due to wear, the cylinder pushes the connecting rod to lift the steel strip, the upper and lower arc plates are quickly pulled out of the sliding groove by manual operation, and a new spare part is replaced.

[0074] The new air cooling structure is provided, the melting furnace 15 is inwardly recessed to form a cavity, the cavity separates the metal molten liquid from the outside, the heat dissipation grid 202 is arranged in the cavity, the fan blows cold air into the cavity through the cavity port I (201), and hot air is blown out of the cavity through the cavity port O (203). The structure has large grid heat exchange area, and the frequency conversion fan blows in appropriate air volume according to system setting to achieve the heat exchange purpose.

[0075] The inlet main water cooling system is provided, when the product is wide and thick steel strip, the required heat exchange amount is large, and therefore the water cooling system must be used. The inlet main water cooling system is arranged below the steel strip inlet, cooling water enters the intermediate small pipe 302 from the water inlet 301, the water is uniformly sprayed to the water distribution plate 304 through the axial pipes of the intermediate small pipe 302 and a plurality of damping plugs 303, the intermediate pipe 305 is eccentric to the inner pipe 308, the water is sprayed to the heated surface through the guide groove of the water distribution plate 304, the heat of the steel strip transferred to the metal molten liquid is conducted to the intermediate pipe 305 through the medium 306 and the outer cooling pipe 307, and the water between the intermediate pipe 305 and the inner pipe 308 carries away the heat and flows out through the water outlet pipe 309.

[0076] In order to effectively control the linear relationship degree of the water carrying away the heat, the heat conducting medium is filled between the outer cooling pipe 307 and the intermediate pipe 305, the heat is conducted through the medium, the direct heat exchange between the water and the outer cooling pipe 307 is reduced to avoid the phenomenon that the metal molten liquid is solidified due to rapid cooling, and the temperature can be controlled.

[0077] The steel strip pressing mechanism is provided, the device is a gantry structure, the gantry 401 can move on the guide rail of the melting pool. When the position is set, the screw is locked with the pool guide rail, and the worm gear box driven thereby can also be self-locked in the axial direction. The sliding frame 402 drives the sliding block 404 to slide up and down in the sliding groove 405 fixed to the gantry through the left and right connecting plates 403, after the two sides of the sliding frame are adjusted with the production line reference, the two worm elevators 408 are integrated through the intermediate transmission shaft 409, and the sliding frame is synchronously lifted through the motor 406, the shaft coupling 407 and the like. The pressing mechanism is adjusted to the position, and the scale 411 can display the position. Different steel strips are positioned at different positions. The sliding frame 402 is locked by the locking screw 410 after being adjusted.

[0078] The arc-shaped plate 412 is provided with a passage for quickly replacing the fiber felt and a press plate for pressing the felt.

[0079] The L-shaped outlet seal is provided, one pair or more pairs of air cylinders 502 can be mounted on the frame body 501 according to the working condition, the air cylinders 502 are locked with the cross beam 503 through nuts, and the cross beam 503 is provided with the sealing fiber felt. During the running of the steel strip, the air cylinders 502 push the cross beam 503 to seal the steel strip and the frame body through the fiber felt 504, the leakage amount of the protective atmosphere is effectively reduced, and the brightness of the steel strip is ensured, so that the steel strip is not oxidized.

[0080] With the development of the metal strip rolling mill technology, the strip product is wider and thinner, and the flatness requirement of the product is higher and higher. For the automobile industry, the flatness of the plate reaches ±10IU, and the plate convexity reaches 10μm, which makes the rolling technology have higher requirements; and the good or bad of the plate shape depends on the distribution of the residual internal stress of the strip, and the residual internal stress is generated in addition to most of the sources from the rolling process; the control of the cooling speed is one of the influencing factors, and in the high temperature annealing cooling process, the cooling speed and the cross section cooling uniformity are important factors affecting the plate shape. In the prior art, the gas cooling method is generally used. However, due to the unreasonable gas cooling structure of the prior art, there are defects of too fast or too slow gas cooling speed, and the cooling speed is too fast or too slow in the high temperature quenching annealing of the strip 1080-900℃, thereby causing uneven cooling, poor stress relieving effect, easy deformation and other problems.

[0081] In practical application, the steel strip is pulled by the S roller, passes through the asbestos fiber support structure 100 and enters the melting furnace 15, the depth and horizontal position of entering the melting furnace 15 are adjusted up and down and front and back according to different product specifications, models and materials. The heat exchange of the high temperature steel strip is coordinated by the air cooling system, the inlet water cooling system, the servo control cooling system 2, the auxiliary cooling device 4 and the electric heating system 9, the control cooling speed Vk is on the left side of the product C curve, the steel strip organization is supercooled austenite, and the temperature and cooling intensity of the melting pool are controlled in the process requirement range through the program.

[0082] In order to adjust the high quality of the quenched and tempered steel strip, the better process in the world at present is the staged quenching: the traditional martensite transformation process (such as oil quenching, water quenching, etc.) is changed into two controllable stages. The austenitized steel strip is cooled in the molten metal for the first time (the temperature is above the martensite transformation point Ms of the product), and the microstructure of the product is still austenite (we call it supercooled austenite), and then the martensite phase change is carried out after the product is out of the melting pool.

[0083] The purpose achieved: the internal organization shrinkage caused by rapid cooling is effectively separated from the expansion caused by the martensite phase change in the subsequent process, the organization stress and phase change stress are generated in different stages, and a good foundation is laid for the excellent organization, flatness and other performance indicators of the product.

[0084] The medium used in the application is safe and reliable, and the automatic control is adopted, which is one of the most core equipment in the process of austenite to martensite in the quenching process of the excellent steel.

[0085] After the steel strip comes out of the furnace, it is pressed into the molten pool by the pressing mechanism for staged quenching, and after coming out of the pool, it enters the outlet box 5, the water cooling jacket 6, the outlet seal 7, and then the next process equipment. There is an asbestos fiber felt support under the steel strip at the inlet, and after entering the pool, a main water cooling system and an air cooling system (selected according to different processed workpieces) are provided below, and servo cooling and auxiliary cooling are designed afterwards. The lower pressing mechanism 3 is adjusted by the lower pressing mechanism adjusting mechanism 10 according to process requirements. The scraper and electric heating system in the outlet box are designed with a phase change controller to ensure that the steel strip is above the martensite transformation point Ms, which lays a foundation for easy flattening afterwards.

[0086] The cooling and heating of the equipment are effectively controlled by the thermocouple in cooperation with the program to control the temperature and cooling intensity. The servo cooling, lower pressing mechanism, and air volume are adjusted by the servo motor in cooperation with the servo system. The scraper in the outlet box scrapes the residual molten metal on the surface of the steel strip clean under the action of the air cylinder.

[0087] The structure diagram is an expression of the product, and the specific process route and operation mode are as follows:

[0088] The workpiece (steel strip) is pulled by the S roller, enters the molten pool (furnace) after passing through the asbestos fiber support, and its depth and horizontal position are adjusted up and down and forward and backward according to product specifications, models, and different materials. The heat exchange of the high-temperature workpiece (steel strip) is coordinated by the air cooling system, the water cooling system, the servo control cooling system, the auxiliary cooling structure, and the electric heating system 9, and the control cooling speed Vk is on the left side of the product C curve. The workpiece (steel strip) is in a supercooled austenite state, and the temperature and cooling intensity of the molten pool are controlled within the process requirements range through the program.

[0089] After the workpiece (steel strip) comes out of the molten pool, the molten liquid on the steel strip is preliminarily removed by the elastic scraper, and then under the action of the air cylinder, three pairs of scrapers wrapped with asbestos fiber scrape off the residual metal liquid. The molten liquid flows into the pool along the slope, and a small amount of it drips into the small box below the scraper, which is cleaned regularly. Nitrogen gas warmed by the electric heating at the bottom is introduced into the outlet box to protect the steel strip from oxidation and ensure its surface brightness. The heating tube at the top and the phase change controller at the bottom keep the temperature in the box above the martensite transformation point through thermocouple detection, while maintaining the fluidity of the metal medium.

[0090] In this embodiment, the water cooling jacket set according to the product process can cool the steel strip (mainly thin strip), and the product is provided with an L-shaped seal.

Claims

1. An improved apparatus for the fractional quenching of molten metal comprising a base frame (8) and a melting furnace (15) arranged on the base frame, characterized in that: The application discloses a molten metal grading quenching device, which comprises a chassis (8), a molten furnace (15), a cooling system (2), a pressing mechanism (3), a wind cooling structure (14), a water cooling structure (13), a phase change control structure (11), a water cooling jacket (6), an outlet sealing structure (7), an outlet box (5), a pressing adjusting mechanism (10), an inlet (1) and an outlet, wherein the inlet (1) is arranged at the front end of the chassis (8), the outlet is arranged at the rear end of the chassis (8), the outlet sealing structure (7) is arranged at the outlet, the molten furnace (15) is arranged at the front end of the chassis (8) and communicates with the inlet (1), a workpiece channel is formed at the upper portion of the molten furnace (15), the cooling system (2) and the pressing mechanism (3) are sequentially arranged above the workpiece channel in the workpiece advancing direction, the wind cooling structure (14) and the water cooling structure (13) are arranged below the workpiece channel and close to the inlet (1), a molten primary quenching structure is formed, the pressing adjusting mechanism (10), the outlet box (5) and the phase change control structure (11) constitute a flattening wind cooling section, the water cooling jacket (6) or the flattening wind cooling section forms a secondary quenching structure, the control ends of the cooling system (2), the pressing mechanism (3), the pressing adjusting mechanism (10), the phase change control structure (11), the water cooling structure (13) and the wind cooling structure (14) of the molten primary quenching structure are connected with the control output ends of a PLC control system, and the molten metal grading quenching device is formed, an asbestos fiber support structure is arranged at the inlet (1), the asbestos fiber support structure is composed of an upper arc plate (101), a lower arc plate (102), a bottom plate (104) and a fiber felt (103), a handle is welded on the upper arc plate (101), a sliding block is arranged on the lower arc plate (102), a sliding groove is formed on the bottom plate (104), the bottom plate (104) is connected with the molten pool through screws, the fiber felt (103) is clamped between the upper arc plate (101) and the lower arc plate (102), and the upper arc plate (101) and the lower arc plate (102) are connected into an integrated body through screws, the wind cooling structure (14) is arranged at the inner recessed cavity of the molten furnace (15) to form a wind cooling structure for the inlet end of the workpiece channel, the wind cooling structure (14) comprises a heat dissipation partition (202), an air inlet (201) and an air outlet (203), the heat dissipation partition (202) is located in the inner recessed cavity and communicates with the air inlet (201) and the air outlet (203), so that cold air is blown into the air inlet (201) and hot air is discharged from the air outlet (203), the molten metal liquid is separated from the outside through the inner recessed cavity, and a heat exchange structure is formed, the phase change control structure (11) comprises a phase change bottom plate (601), a heating device (602), a phase change frame body (603), a connecting screw (604) and a thermocouple (605), the phase change control structure (11) is arranged below the outlet box (5) and located on the bottom surface of the workpiece, and is used for temperature control of the workpiece together with the heating device at the upper portion of the outlet box (5), so that the workpiece is kept in a supercooled austenite state, and the heat output is detected by the thermocouple and controlled by a program.

2. An improved molten metal fractional quenching apparatus as claimed in claim 1 wherein: The water cooling structure (13) is arranged at the lower side of the workpiece channel at the inlet (1), forms a water cooling structure at the inlet end of the workpiece channel, comprises a water inlet pipe (301), a heat exchange device and a water outlet pipe (309), the heat exchange device is a tubular structure, comprises an inner pipe (308) and an outer cooling pipe (307), an intermediate pipe (305) is arranged between the inner pipe (308) and the outer cooling pipe (307), an intermediate small pipe (302) is arranged in the inner cavity of the inner pipe (308), a plurality of damping plugs (303) and water distribution plates (304) are arranged in the intermediate small pipe (302), the two ends of the inner pipe (308) are communicated with the water inlet pipe (301) and the water outlet pipe (309) respectively, the intermediate small pipe (302) is fixedly connected to the inner wall of the inner pipe (308) through the water distribution plates (304), the water inlet of the intermediate small pipe (302) is communicated with the inner pipe (308); the water distribution plates (304) are in a "U" shape, the inner cavities of the water distribution plates (304) are communicated with the inner cavities of the intermediate small pipe (302); cooling water enters the inner pipe (308) from the water inlet pipe (301), then enters the intermediate small pipe (302) and is sprayed to the water distribution plates (304) along the axial direction of the pipe through the plurality of damping plugs (303) to uniformly spray water to the water distribution plates (304), the water is sprayed to the heated surface of the inner pipe (308) through the guide grooves of the water distribution plates (304) to form a water heat exchange structure; in the water cooling structure (13), a heat conducting medium (306) is filled between the outer cooling pipe (307) and the intermediate pipe (305) to effectively control the linear relationship degree of heat carried away by water, through the conduction of the heat conducting medium (306), the direct heat exchange between water and the outer cooling pipe (307) to produce vaporization is reduced, the phenomenon that the molten metal solidifies due to too fast cooling is avoided, and the temperature can be controlled.

3. An improved molten metal fractional quenching apparatus as claimed in claim 1, wherein: The lower pressing mechanism (3) is a gantry structure, including a gantry (401) and a sliding frame (402), two sliding groove structures (405) are arranged on the inner sides of the gantry (401), sliding blocks (404) are arranged in the sliding groove structures (405), the two sides of the sliding frame (402) are directly connected with the sliding blocks (404) or are connected with the sliding blocks (404) through connecting plates (403), the upper end of the sliding frame (402) is connected with a worm lifting mechanism (408), the two sides of the sliding frame (402) are positioned and connected with the gantry (401) through screws, a positionable upper and lower sliding connection structure is formed, the bottom surface of the sliding frame (402) is connected with an arc plate structure (412) for pressing a workpiece, a lower arch-shaped lower pressing mechanism is formed, the gantry (401) is arranged on a guide rail of a melting furnace (15) and can move and be positioned horizontally on the guide rail, the gantry (401) is locked by screws after being positioned on the guide rail, and a movable structure is formed, the worm lifting mechanism (408) comprises a motor (406), a shaft coupling (407) and two worm gear / worm structures, the motor (406) is fixed on the gantry (401), the output shaft of the motor (406) is connected with the worm gear / worm structures through the shaft coupling (407), and the two worm gear / worm structures are connected through an intermediate transmission shaft (409) to form a linkage structure, the sliding frame (402) is synchronously lifted and lowered through the worm lifting mechanism (408), a scale (411) is arranged in the lower pressing mechanism (3) and is used for displaying the position of the sliding frame (402) of the lower pressing mechanism (3) in the up and down adjustment and positioning, so that different workpiece thicknesses can be adapted, and the sliding frame (402) is locked by lock screws (410) after being adjusted, the arc plate structure (412) of the lower pressing mechanism (3) comprises upper and lower arc plates and fiber felt clamped between the upper and lower arc plates, a passage for quickly replacing the fiber felt and a pressing plate for pressing the felt are arranged on the upper arc plate.

4. An improved molten metal fractional quenching apparatus as claimed in claim 1, wherein: The outlet sealing structure (7) is an L-shaped outlet sealing structure, comprising a frame body (501), one or more pairs of air cylinders (502) are arranged at the front end of the frame body (501), one or more pairs of cross beams (503) are arranged in the inner cavity of the frame body (501), and a sealing fiber layer (504) is arranged on the opposite surfaces of each pair of cross beams (503); the cross beams (503) are arranged on the upper and lower sides of a workpiece channel and seal the workpiece, the front part of the cross beam (503) is connected with the telescopic rod of the air cylinder (502), and the rear end is fixed on the rear inner wall of the frame body (501), so that the air cylinder (502) drives the cross beam (503) to seal the contact surface between the workpiece and the frame body (501) and the outlet water cooling jacket through the sealing fiber layer (504), so as to prevent or reduce the leakage of the protective atmosphere and ensure that the workpiece is bright and not oxidized.

5. An improved molten metal fractional quenching apparatus as claimed in claim 1, wherein: The outlet box (5) comprises a box body (901), a box cover (902), a swing cylinder (903), a pressing cylinder (904), an inspection door (905), a scraper group (906), a heater (907), a wiper (908) and a nitrogen pipe (909), a thermocouple and a thermal insulation asbestos layer are arranged in the inner cavity of the box body (901); after the steel belt is discharged from the melting furnace (15), the medium left on the surface is scraped off by the wiper (908), then the swing cylinder (903) and the pressing cylinder (904) jointly flatten the steel belt by pressing the scraper group (906) and use the asbestos felt arranged above the scraper group (906) to wipe off the residual medium; the heater (907) is used for supplementing the loss of heat so that the steel belt will not change phase; the heated nitrogen is filled into the box through the nitrogen pipe (909) to protect the brightness of the steel belt.

6. An improved molten metal fractional quenching apparatus as claimed in claim 1 wherein: The water cooling jacket (6) comprises a jacket body, a water inlet pipe (801), a communication pipe (802), a water outlet pipe (803), a partition plate (804) and a graphite block (805) arranged in the jacket body, the cavity of the jacket body is welded into four cavities by steel plates, which are used for cooling the outlet of the steel belt to increase the strength and hardness of the workpiece; the cooling water enters from the water inlet pipe (801), flows into one of the lower cavities (L1), returns from the lower part of the partition plate (804) to the other lower cavity (L2), then enters one of the upper cavities (L3) through the water outlet pipe (803), enters the other upper cavity (L4) through the upper part of the partition plate (804) and flows into the pool through the water outlet pipe (803); the graphite block (805) is arranged in the water cooling jacket and is used for supporting the steel belt.

7. An improved molten metal fractional quenching apparatus as claimed in claim 1 wherein: The downward adjusting mechanism (10) is fixed on the base frame (8) and comprises a worm lifting machine (701), an adjusting coupling (702), a transmission shaft (703), a hand wheel (705), a connecting rod (704) and a pin shaft (706); when the downward mechanism (3) needs to be adjusted forward and backward according to the process requirement, the worm box connected by the transmission shaft and the adjusting coupling is shaken by the hand wheel (705), the worm is driven by the worm wheel to move forward and backward along the axial direction, then the pin shaft (706) and the connecting rod (704) connected with the pin shaft (706) are driven to move horizontally, the downward mechanism and the connecting rod (704) are connected through the pin shaft, and the downward mechanism is locked after reaching the specified position as required.

8. An improved molten metal fractional quenching apparatus as claimed in claim 1 wherein: Auxiliary cooling structure (4) is arranged between the pressing mechanism (3) and the outlet box (5), and the auxiliary cooling structure (4) comprises a mounting frame (1001), one of water pipes (1002), the second water pipe (1003), a transmission rod (1004), a swing mechanism (1005) and a crank (1006); the mounting frame (1001) and the plate of the crank (1006) are fixedly connected, the plate is provided with a waist-shaped sliding groove, the swing mechanism (1005) moves up, down, left and right in the waist-shaped sliding groove, so that the cooling position of the water pipe to the steel belt is adjusted, and the ideal process requirement is achieved; the electric heating structure (9) is arranged in the melting furnace (15), so that the melting furnace (15) is heated; the lining (12) is arranged on the inner side wall of the melting furnace (15), and the dust cover is arranged on the outer surface of the melting furnace (15) to prevent pollution.

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