Device and method for achieving core part press-down technology in continuous casting round billet solidification process

Abstract

A device for achieving a core part press-down technology in a continuous casting round billet solidification process includes a plurality of round billet radial press-down devices distributed along an axial array of round billets outside a press-down interval of the round billets. The press-down interval is an area from 0.65 of a solid phase ratio of the round billets to solidification end points. Each round billet radial press-down device includes a plurality of press-down rollers. A forming hole for extruding the round billets is formed between the press-down rollers. Two adjacent round billet radial press-down devices are arranged in the manner of staggering. The device can effectively solve the defect problems of porosity, segregation and the like in the core of the continuous casting round billets, the yield of the continuous casting round billets is increased, and the production cost is reduced.

Claims

1. A device for achieving a core part press-down technology in a continuous casting round billet solidification process, comprising a plurality of round billet radial press-down devices distributed along an axial array of round billets outside a press-down interval of the round billets, and the press-down interval being an area from 0.65 of a solid phase ratio of the round billets to solidification end points; wherein each round billet radial press-down device comprises three press-down rollers distributed along a circumference of a central axis of the round billets in an array; a forming hole for extruding the round billets is formed between the three press-down rollers of each round billet radial press-down device; and forming holes of the round billet radial press-down devices near forming ends of the round billets and the forming holes of the round billet radial press-down devices near solidification ends of the round billets are formed in a gradual change manner from a triangle to a circle; wherein two adjacent round billet radial press-down devices are arranged in a manner of staggering by 180 degrees; wherein a water cutting plate is arranged at an outer side of each press-down roller, and a shape of the water cutting plate corresponds with a roller shape of each press-down roller; and wherein the press-down rollers of each round billet radial press-down device have a function of opening and closing along a radial direction of the round billets.

2. The device according to claim 1, wherein a total number of the round billet radial press-down devices are two to five.

3. The device according to claim 1, wherein each press-down roller is made of heat-resistant steel.

4. A method for achieving a core part press-down technology in a continuous casting round billet solidification process by using the device for achieving the core part press-down technology in the continuous casting round billet solidification process according to claim 1, the method comprising the following steps: step 1: importing a material, a diameter and a casting speed of each of the round billets, a crystallizer water amount of a casting machine and a water amount of a secondary cooling zone into a finite element analysis software; determining a solid phase ratio at a beginning of press-down through a finite element analysis, and determining a starting position and an ending position of a press-down interval; step 2: running the round billets from an outlet of the casting machine to the round billet radial press-down devices along an axial direction of the round billets, when the round billets reach the round billet radial press-down devices, the round billets start to be pressed down by the round billet radial press-down devices, and after all the round billets pass through the round billet radial press-down devices, the press-down is stopped; and step 3: spraying cooling water onto an outer surface of each press-down roller to cool each press-down roller during the press-down of the round billet radial press-down devices, and the cooling water after cooling flowing back to an equipment cooling water system of the casting machine along the water cutting plate of each press-down roller.

5. The method according to claim 4, wherein a press-down rate of a single round billet radial press-down device is 5%-40%, and a total press-down rate of the device for achieving a core part press-down technology in a continuous casting round billet solidification process is 10%-60%.

6. A device for achieving a core part press-down technology in a continuous casting round billet solidification process, comprising a plurality of round billet radial press-down devices distributed along an axial array of round billets outside a press-down interval of the round billets, and the press-down interval being an area from 0.65 of a solid phase ratio of the round billets to solidification end points; wherein each round billet radial press-down device comprises two press-down rollers distributed along a circumference of a central axis of the round billets in an array; a forming hole for extruding the round billets is formed between the two press-down rollers of each round billet radial press-down device; and forming holes of the round billet radial press-down devices near forming ends of the round billets and forming holes of the round billet radial press-down devices near solidification ends of the round billets are formed in a gradual change manner from an elliptic to a circle; wherein two adjacent round billet radial press-down devices are arranged in a manner of staggering by 90 degrees; wherein a water cutting plate is arranged at an outer side of each press-down roller, and a shape of the water cutting plate corresponds with a roller shape of each press-down roller; and wherein the press-down rollers of each round billet radial press-down device have a function of opening and closing along a radial direction of the round billets.

7. The device according to claim 6, wherein a total number of the round billet radial press-down devices are two to five.

8. The device according to claim 6, wherein each press-down roller is made of heat-resistant steel.

9. A method for achieving a core part press-down technology in a continuous casting round billet solidification process by using the device for achieving the core part press-down technology in the continuous casting round billet solidification process according to claim 6, the method comprising the following steps: step 1: importing a material, a diameter and a casting speed of each of the round billets, a crystallizer water amount of a casting machine and a water amount of a secondary cooling zone into a finite element analysis software; determining a solid phase ratio at a beginning of press-down through a finite element analysis, and determining a starting position and an ending position of a press-down interval; step 2: running the round billets from an outlet of the casting machine to the round billet radial press-down devices along an axial direction of the round billets, when the round billets reach the round billet radial press-down devices, the round billets start to be pressed down by the round billet radial press-down devices, and after all the round billets pass through the round billet radial press-down devices, the press-down is stopped; and step 3: spraying cooling water onto an outer surface of each press-down roller to cool each press-down roller during the press-down of the round billet radial press-down devices, and the cooling water after cooling flowing back to an equipment cooling water system of the casting machine along the water cutting plate of each press-down roller.

10. The method according to claim 9, wherein a press-down rate of a single round billet radial press-down device is 5%-40%, and a total press-down rate of the device for achieving a core part press-down technology in a continuous casting round billet solidification process is 10%-60%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which:

(2) FIG. 1 is a schematic diagram of defects of porosity and segregation in the prior art;

(3) FIG. 2 is a schematic diagram of round billets after being drilled in the prior art;

(4) FIG. 3 is a schematic structural diagram of embodiment 1 of the present invention;

(5) FIG. 4 is a schematic diagram of a round billet radial press-down device with an arc triangular forming hole according to embodiment 1 of the present invention;

(6) FIG. 5 is a schematic diagram of a round billet radial press-down device with a circular forming hole according to embodiment 1 of the present invention;

(7) FIG. 6 is a schematic diagram of a round billet radial press-down device with a triangular forming hole according to embodiment 2 of the present invention;

(8) FIG. 7 is a schematic structural diagram of embodiment 3 of the present invention;

(9) FIG. 8 is a schematic diagram of a round billet radial press-down device with an elliptic forming hole according to embodiment 3 of the present invention;

(10) FIG. 9 is a schematic diagram of a round billet radial press-down device with a circular forming hole according to embodiment 3 of the present invention; and

(11) FIG. 10 is a schematic structural diagram of mounting of a water cutting plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(12) It should be noted that all directional indicators (such as upper, lower, left, right, front and rear) in the embodiment of the invention are only used to explain the relative positional relationship, movement, and the like. between various components under a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indicator will also change accordingly.

Embodiment 1

(13) As shown in FIGS. 3-5, the embodiment provides a device for achieving a core part press-down technology in a continuous casting round billet solidification process. The device for achieving a core part press-down technology in a continuous casting round billet solidification process comprises two round billet radial press-down devices 2. The two round billet radial press-down devices 2 are distributed along an axial straight line array of round billets 1 outside a press-down interval of the round billets 1, and the press-down interval is an area from 0.85 of a solid phase ratio of the round billets 1 to solidification end points (behind an effective secondary cooling area and in front of a pulling and straightening machine). Each round billet radial press-down device 2 comprises three press-down rollers 3 distributed along a circumference of a central axis of the round billets 1 in an array. Each press-down roller 3 is made of heat-resistant steel roller. A forming hole 4 for extruding the round billets 1 is formed between the three press-down rollers 3 of each round billet radial press-down device 2. The forming holes 4 of the round billet radial press-down devices 2 near forming ends of the round billets 1 are arc triangular, as shown in FIG. 4. The forming holes 4 near solidification ends of the round billets 1 are circular, as shown in FIG. 5. Two adjacent round billet radial press-down devices 2 are arranged in a manner of staggering by 180 degrees. An interval between the two adjacent round billet radial press-down devices 2 is 1 m. A water cutting plate 5 is arranged at an outer side of each press-down roller 3, as shown in FIG. 10. A shape of the water cutting plate 5 corresponds with a roller shape of each press-down roller 3. The press-down rollers 3 of each round billet radial press-down device 2 have a function of opening and closing along a radial direction of the round billets 1.

(14) It should be noted that when one of the round billet radial press-down devices 2 is mounted near the solidification ends of the round billets 1, an electromagnetic stirring device at the end needs to be moved upward.

(15) A method for achieving a core part press-down technology in a continuous casting round billet solidification process by using the aforementioned device for achieving the core part press-down technology in a continuous casting round billet solidification process, the method comprises the following steps:

(16) Step 1: importing a material, a diameter and a casting speed of the round billets 1, a crystallizer water amount of a casting machine and a water amount of a secondary cooling zone into a finite element analysis software. In the embodiment, the diameter of the round billets 1 is 600 mm and the material is Q235 steel; the round billets 1 are cast by a full arc continuous casting machine at a casting speed of 0.22 m/s, with an arc radius of 14 m; and a target diameter of 570 mm; determining a solid phase ratio at a beginning of press-down to be 0.85 through a finite element analysis, and, determining a starting position and an ending position of a press-down interval;

(17) Step 2: running the round billets 1 from an outlet of the casting machine to the round billet radial press-down devices 2 along an axial direction of the round billets, when the round billets 1 reach the round billet radial press-down devices 2, the round billets 1 start to be pressed down by the round billet radial press-down devices 2, and after all the round billets 1 pass through the round billet radial press-down devices 2, the press-down is stopped; and

(18) Step 3: spraying cooling water onto an outer surface of each press-down roller 3 to cool each press-down roller 3 during the press-down of the round billet radial press-down devices 2, and the cooling water after cooling flowing back to an equipment cooling water system of the casting machine along the water cutting plate 5 of each press-down roller 3 to prevent the cooling water from falling onto the surfaces of the round billets 1 and enable the round billets 1 to be rapidly cooled.

(19) It should be noted that running of the round billet radial press-down devices 2 are controlled in synchronization with the casting machine to meet the normal operation of the casting machine, and a linear speed of each press-down roller 3 is not lower than a billet casting speed of the continuous casting machine.

(20) A press-down rate of a single round billet radial press-down device 2 is 5%, and the total press-down rate of the device for achieving a core part press-down technology in a continuous casting round billet solidification process is 10%.

(21) The continuous casting round billets 1 sequentially pass through a crystallizer, an effective secondary cooling zone and an air cooling zone to enter the press-down interval, and then sequentially pass through the two round billet radial press-down devices 2. The diameter of the continuous casting round billets 1 is reduced from 600 mm to 570 mm, and at this time, the continuous casting round billets 1 are completely solidified and are straightened by a pulling and straightening machine.

(22) After the press-down treatment, a central porosity level is decreased from 2.0-1.5 to 1.0, and a central segregation level is less than 1.0.

Embodiment 2

(23) The embodiment provides a device for achieving a core part press-down technology in a continuous casting round billet solidification process. The device for achieving a core part press-down technology in a continuous casting round billet solidification process comprises three round billet radial press-down devices 2. The three round billet radial press-down devices 2 are distributed along an axial straight line array of round billets 1 outside a press-down interval of the round billets 1, and the press-down interval is an area from 0.65 of a solid phase ratio of the round billets 1 to solidification end points (behind an effective secondary cooling area and in front of a pulling and straightening machine). Each round billet radial press-down device 2 comprises three press-down rollers 3 distributed along a circumference of a central axis of the round billets 1 in an array. Each press-down roller 3 is made of heat-resistant steel. A forming hole 4 for extruding the round billets 1 is formed between the three press-down rollers 3 of each round billet radial press-down device 2. The forming holes 4 of the round billet radial press-down devices 2 near forming ends of the round billets 1 are flat triangular, as shown in FIG. 6. The forming holes 4 near solidification ends of the round billets 1 are circular, as shown in FIG. 5. The forming holes 4 of the middle round billet radial press-down devices 2 are arc triangular. Two adjacent round billet radial press-down devices 2 are arranged in a manner of staggering by 180 degrees. The interval between the two adjacent round billet radial press-down devices 2 is 1 m A water cutting plate 5 is arranged at an outer side of each press-down roller 3. A shape of the water cutting plate 5 corresponds with a roller shape of each press-down roller 3. The press-down rollers 3 of each round billet radial press-down device 2 have a function of opening and closing along a radial direction of the round billets 1.

(24) It should be noted that when one of the round billet radial press-down device 2 is mounted near the solidification ends of the round billets 1, an electromagnetic stirring device at the end needs to be moved upward.

(25) A method for achieving a core part press-down technology in a continuous casting round billet solidification process by using the aforementioned device for achieving the core part press-down technology in a continuous casting round billet solidification process, the method comprises the following steps:

(26) Step 1: importing a material, a diameter and a casting speed of the round billets 1, a crystallizer water amount of a casting machine and a water amount of a secondary cooling zone into a finite element analysis software. In the embodiment, the diameter of the round billets 1 is 360 mm and the material is Q345 steel; casting is performed at a casting speed of 0.8-1 m/s; and a target diameter of 300 mm; determining a solid phase ratio at a beginning of press-down to be 0.65 through a finite element analysis, and, determining a starting position and an ending position of a press-down interval;

(27) Step 2: running the round billets 1 from an outlet of the casting machine to the round billet radial press-down devices 2 along an axial direction of the round billets, when the round billets 1 reach the round billet radial press-down devices 2, the round billets 1 start to be pressed down by the round billet radial press-down devices 2, and after all the round billets 1 pass through the round billet radial press-down devices 2, the press-down is stopped; and

(28) Step 3: spraying cooling water onto an outer surface of each press-down roller 3 to cool each press-down roller 3, during the press-down of the round billet radial press-down devices 2, and the cooling water after cooling flowing back to an equipment cooling water system of the casting machine along the water cutting plate 5 of each press-down roller 3 to prevent the cooling water from falling onto the surfaces of the round billets 1 and enable the round billets 1 to be rapidly cooled.

(29) It should be noted that running of the round billet radial press-down devices 2 are controlled in synchronization with the casting machine to meet the normal operation of the casting machine, and a linear speed of each press-down roller 3 is not lower than a billet casting speed of the continuous casting machine.

(30) A press-down rate of a single round billet radial press-down device 2 is 5.56%, and the total press-down rate of the device for achieving a core part press-down technology in a continuous casting round billet solidification process is 16.7%.

(31) The continuous casting round billets 1 sequentially pass through a crystallizer, an effective secondary cooling zone and an air cooling zone to enter the press-down interval, and then sequentially pass through the two round billet radial press-down devices 2. The diameter of the continuous casting round billets 1 is reduced from 360 mm to 300 mm, and at this time, the continuous casting round billets 1 are completely solidified and are straightened by a pulling and straightening machine.

(32) After the press-down treatment, through observation of macrostructure, the segregation in the core part of the billets is basically eliminated, and the segregation in ½ region and ¼ region is completely eliminated. A central porosity level is better than 0.5 and a shrinkage cavity does not exist.

Embodiment 3

(33) As shown in FIGS. 7-9, the embodiment provides a device for achieving a core part press-down technology in a continuous casting round billet solidification process. The device for achieving a core part press-down technology in a continuous casting round billet solidification process comprises four round billet radial press-down devices 2. The four round billet radial press-down devices 2 are distributed along an axial straight line array of round billets 1 outside a press-down interval of the round billets 1, and the press-down interval is an area from 0.75 of a solid phase ratio of the round billets 1 to solidification end points (behind an effective secondary cooling area and in front of a pulling and straightening machine). Each round billet radial press-down device 2 comprises two press-down rollers 3 distributed along a circumference of a central axis of the round billets 1 in an array. Each press-down roller 3 is made of heat-resistant steel. A forming hole 4 for extruding the round billets 1 is formed between the two press-down rollers 3 of each round billet radial press-down device 2. The forming holes 4 of the round billet radial press-down devices 2 near forming ends of the round billets 1 and the forming holes 4 of the round billet radial press-down devices 2 near solidification ends of the round billets 1 are formed in a gradual change manner from an elliptic to a circle. Specifically, the forming holes 4 of the three round billet radial press-down devices 2 near the forming ends of the round billets are elliptic, and the forming holes 4 of the round billet radial press-down devices 2 near the solidification ends of the round billets 1 are circular. Two adjacent round billet radial press-down devices 2 are arranged in a manner of staggering by 90 degrees. An interval between the two adjacent round billet radial press-down devices 2 is 1 m. A water cutting plate 5 is arranged at an outer side of each press-down roller 3. A shape of the water cutting plate 5 corresponds with a roller shape of each press-down roller 3. The press-down rollers 3 of each round billet radial press-down device 2 have a function of opening and closing along a radial direction of the round billets 1.

(34) It should be noted that when one of the round billet radial press-down devices 2 is mounted near the solidification ends of the round billets 1, an electromagnetic stirring device at the end needs to be moved upward.

(35) A method for achieving a core part press-down technology in a continuous casting round billet solidification process by using the aforementioned device for achieving the core part press-down technology in a continuous casting round billet solidification process, the method comprises the following steps:

(36) Step 1: importing a material, a diameter and a casting speed of the round billets 1, a crystallizer water amount of a casting machine and a water amount of a secondary cooling zone into a finite element analysis software. In the embodiment, the diameter of the round billets 1 is 300 mm and the material is 15CrMo steel; casting is performed at a casting speed of 0.7-1 m/s; and a target diameter of 180 mm; determining a solid phase ratio at a beginning of press-down to be 0.75 through a finite element analysis, and determining a starting position and an ending position of a press-down interval;

(37) Step 2: running the round billets 1 from an outlet of the casting machine to the round billet radial press-down devices 2 along an axial direction of the round billets, when the round billets 1 reach the round billet radial press-down devices 2, the round billets 1 start to be pressed down by the round billet radial press-down devices 2, and after all the round billets 1 pass through the round billet radial press-down devices 2, the press-down is stopped; and

(38) Step 3: spraying cooling water onto an outer surface of each press-down roller 3 to cool each press-down roller 3, during the press-down of the round billet radial press-down devices 2, and the cooling water after cooling flowing back to an equipment cooling water system of the casting machine along the water cutting plate 5 of each press-down roller 3 to prevent the cooling water from falling onto the surfaces of the round billets 1 and enable the round billets 1 to be rapidly cooled.

(39) It should be noted that running of the round billet radial press-down devices 2 are controlled in synchronization with the casting machine to meet the normal operation of the casting machine, and a linear speed of each press-down roller 3 is not lower than a billet casting speed of the continuous casting machine.

(40) A press-down rate of a single round billet radial press-down device 2 is 10%, and the total press-down rate of the device for achieving a core part press-down technology in a continuous casting round billet solidification process is 40%.

(41) The continuous casting round billets 1 sequentially pass through a crystallizer, an effective secondary cooling zone and an air cooling zone to enter the press-down interval, and then sequentially pass through the two round billet radial press-down devices 2. The diameter of the continuous casting round billets 1 is reduced from 300 mm to 180 mm, and at this time, the continuous casting round billets 1 are completely solidified and are straightened by a pulling and straightening machine.

(42) After the press-down treatment, through observation of macrostructure, a central porosity level is reduced to 1.5 or below, and a central segregation level is reduced to 1.0 or below.

Embodiment 4

(43) The embodiment provides a device for achieving a core part press-down technology in a continuous casting round billet solidification process. The device for achieving a core part press-down technology in a continuous casting round billet solidification process comprises five round billet radial press-down devices 2. The five round billet radial press-down devices 2 are distributed along an axial straight line array of round billets 1 outside a press-down interval of the round billets 1, and the press-down interval is an area from 0.65 of a solid phase ratio of the round billets 1 to solidification end points (behind an effective secondary cooling area and in front of a pulling and straightening machine). Each round billet radial press-down device 2 comprises two press-down rollers 3 distributed along a circumference of a central axis of the round billets 1 in an array. Each press-down roller 3 is made of heat-resistant steel. A forming hole 4 for extruding the round billets 1 is formed between the two press-down rollers 3 of each round billet radial press-down device 2. The forming holes 4 of the round billet radial press-down devices 2 near the forming ends of the round billets 1 and the forming holes 4 of the round billet radial press-down devices 2 near the solidification ends of the round billets 1 are formed in a gradual change manner from an elliptic to a circle. Specifically, the forming holes 4 of the three round billet radial press-down devices 2 near the forming ends of the round billets are elliptic, and the forming holes 4 of the round billet radial press-down devices 2 near the solidification ends of the round billets 1 are circular. Two adjacent round billet radial press-down devices 2 are arranged in a manner of staggering by 90 degrees. An interval between the two adjacent round billet radial press-down devices 2 is 1 m. A water cutting plate 5 is arranged at an outer side of each press-down roller 3. A shape of the water cutting plate 5 corresponds with a roller shape of each press-down roller 3. The press-down rollers 3 of each round billet radial press-down device 2 have a function of opening and closing along a radial direction of the round billets 1.

(44) It should be noted that when one of the round billet radial press-down devices 2 is mounted near the solidification ends of the round billets 1, an electromagnetic stirring device at the end needs to be moved upward.

(45) A method for achieving a core part press-down technology in a continuous casting round billet solidification process by using the aforementioned device for achieving the core part press-down technology in a continuous casting round billet solidification process, the method comprises the following steps:

(46) Step 1: importing a material, a diameter and a casting speed of the round billets 1, a crystallizer water amount of a casting machine and a water amount of a secondary cooling zone into a finite element analysis software. In the embodiment, the diameter of the round billets 1 is 200 mm and the material is Q235B steel; casting is performed at a casting speed of 0.8-1.3 m/s; and a target diameter of 80 mm; determining a solid phase ratio at a beginning of press-down to be 0.65 through a finite element analysis, and determining a starting position and an ending position of a press-down interval;

(47) Step 2: running the round billets 1 from an outlet of the casting machine to the round billet radial press-down devices 2 along an axial direction of the round billets, when the round billets 1 reach the round billet radial press-down devices 2, the round billets 1 start to be pressed down by the round billet radial press-down devices 2, and after all the round billets 1 pass through the round billet radial press-down devices 2, the press-down is stopped; and

(48) Step 3: spraying cooling water onto an outer surface of each press-down roller 3 to cool each press-down roller 3, during the press-down of the round billet radial press-down devices 2, and the cooling water after cooling flowing back to an equipment cooling water system of the casting machine along the water cutting plate 5 of each press-down roller 3 to prevent the cooling water from falling onto the surfaces of the round billets 1 and enable the round billets 1 to be rapidly cooled.

(49) It should be noted that running of the round billet radial press-down devices 2 are controlled in synchronization with the casting machine to meet the normal operation of the casting machine, and a linear speed of each press-down roller 3 is not lower than a billet casting speed of the continuous casting machine.

(50) A press-down rate of a single round billet radial press-down device 2 is 12%, and the total press-down rate of the device for achieving a core part press-down technology in a continuous casting round billet solidification process is 60%.

(51) The continuous casting round billets 1 sequentially pass through a crystallizer, an effective secondary cooling zone and an air cooling zone to enter the press-down interval, and then sequentially pass through the two round billet radial press-down devices 2. The diameter of the continuous casting round billets 1 is reduced from 200 mm to 80 mm, and at this time, the continuous casting round billets 1 are completely solidified and are straightened by a pulling and straightening machine.

(52) After the press-down treatment, through observation of macrostructure, a central porosity level and a central segregation level are both reduced to 1.0 or below.

(53) The above embodiments are only used to illustrate without limiting the technical solution of the invention. Although the invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can still be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which should be covered by the scope of the claims.