Plate shape modulation method for quenched plate with thin specification of 10 mm and below

Abstract

The invention discloses a plate shape modulation method for a quenched plate with the thin specification of 10 mm and below, and relates to the technical field of heat treatment quenching. The method comprises the steps that the included angle between an upper nozzle and an upper roller face of a quenching machine is controlled to be equal to the included angle between a lower nozzle and a lower roller face of the quenching machine; the height of the roll gap is set to be x + h, x is the distance between a lower nozzle of the quenching machine and the lower roll surface, and h is the thickness of the steel plate; and controlling the distance between the upper roller surface and the upper surface of the steel plate to be 0 when the steel plate is quenched. The shape of the quenched and tempered plate can be controlled, deformation in the unified direction is improved, straightening is facilitated, or the straightness required by customers is met without straightening.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment and quenching, in particular to a plate shape modulation method for a thin quenching plate of 10 mm or less. Background Art

[0002] At present, thin-gauge quenched and tempered plates of 10mm and below have serious deflection after quenching due to inaccurate parameter settings, and cannot meet the straightness requirements of customers. Some steel plates are difficult to straighten due to plate shape problems such as single-sided waves and head and tail S-bends. In order to ensure the straightness requirements of the steel plates, repeated straightening or re-quenching or tempering to relieve stress straightening are required, which increases production costs and energy consumption. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the disadvantages of the prior art and provide a plate shape modulation method for a thin quenched plate of 10 mm or less.

[0004] In order to solve the above technical problems, the technical solution of the present invention is as follows: A method for adjusting the shape of a thin quenched plate of 10 mm or less, comprising: Control the angle between the upper nozzle and the upper roller surface of the quenching machine to be equal to the angle between the lower nozzle and the lower roller surface of the quenching machine; The height of the roll gap is set to x+h, where x is the distance between the lower nozzle of the quenching machine and the lower roll surface, and h is the thickness of the steel plate; When the steel plate is quenched, the distance between the upper roller surface and the upper surface of the steel plate is controlled to be 0.

[0005] As a preferred solution of the plate shape modulation method of the thin quenched plate of 10 mm and below described in the present invention, it also includes: setting the water ratio to 1.2~1.4.

[0006] As a preferred solution of the plate shape modulation method of the thin quenched plate of 10 mm or less of the present invention, after setting the water ratio to 1.2-1.4, it also includes: Determine the minimum value w of the total water volume, and set the water supply volume to w / 2.2~2.4.

[0007] As a preferred solution of the plate shape modulation method of the thin quenched plate of 10 mm and below described in the present invention, it also includes: controlling the water pressure of the high-pressure water to 0.8±0.03MPa, and controlling the water pressure of the low-pressure water to 0.4±0.05MPa.

[0008] As a preferred solution of the plate shape modulation method of the thin quenched plate of 10 mm and below described in the present invention, it also includes: controlling the roller speed of the quenching machine to 0.25~0.48m / s.

[0009] The beneficial effects of the present invention are: (1) The present invention controls the distance between the upper roller and the upper surface of the steel plate to be 0 during quenching of the steel plate, which can inhibit the surface deformation of the steel plate to a certain extent and offset a part of the thermal stress deformation caused by rapid cooling of the steel plate.

[0010] (2) The present invention sets the water ratio to 1.2-1.4, which meets the requirement of a small difference in upper and lower water volumes.

[0011] (3) The present invention can control the shape of the quenched and tempered plate and improve it to deform in a uniform direction, which is convenient for straightening or meets the straightness requirements of customers without straightening. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0013] Figure 1 This is an operation schematic diagram of step S101 in the plate shape modulation method for a thin quenched plate of 10 mm or less provided by the present invention; Figure 2 This is a schematic diagram of the operation of step S102 in the plate shape modulation method for thin quenched plates of 10 mm or less provided by the present invention. DETAILED DESCRIPTION

[0014] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific implementation modes and in combination with the accompanying drawings.

[0015] The present application provides a method for adjusting the shape of a thin quenched plate of 10 mm or less, the method specifically comprising the following steps: Step S101: Control the angle between the upper nozzle of the quenching machine and the upper roller surface to be equal to the angle between the lower nozzle of the quenching machine and the lower roller surface.

[0016] For details, see Figure 1 , ensure that the upper nozzle and the lower nozzle of the quenching machine are symmetrically arranged, that is, the angle between the upper nozzle and the center of the roll gap and the angle between the lower nozzle and the center of the roll gap are both α.

[0017] Step S102: setting the height of the roll gap to x+h, wherein x is the distance between the lower nozzle of the quenching machine and the lower roll surface, and h is the thickness of the steel plate.

[0018] Specifically, the plane distance x between the lower nozzle of the quenching machine and the lower roller surface is measured, and the thickness of the steel plate is determined to be h, and then the height of the roller gap is set to x+h.

[0019] Step S103: When the steel plate is quenched, the distance between the upper roller surface and the upper surface of the steel plate is controlled to be 0.

[0020] Specifically, when the steel plate is quenched, the distance between the upper roller and the upper surface of the steel plate is 0, which can inhibit the deformation of the steel plate surface to a certain extent and offset part of the thermal stress deformation caused by the rapid cooling of the steel plate.

[0021] It should be noted that when there is a steel plate in the quenching machine, the height of the roller gap needs to be raised to x+h to ensure that the upper roller surface fits the upper surface of the steel plate.

[0022] Step S104: Set the water ratio to 1.2-1.4.

[0023] Specifically, the water ratio is set at 1.2~1.4 through the measurement of the gravitational acceleration of cooling water to meet the requirement of a small difference in upper and lower water volumes.

[0024] Step S105: Determine the minimum value w of the total water volume, and set the water supply volume to w / 2.2~2.4.

[0025] Specifically, according to performance confirmation, the minimum total water volume is w (not exceeding the total water volume set in the pipeline), which can be evenly distributed to each group of gaps or set in a larger front and smaller back manner. The overall upstream water volume is w / 2.2~2.4, and the downstream water volume is automatically displayed according to the water ratio.

[0026] Step S106: Control the high-pressure water pressure to 0.8±0.03MPa, and control the low-pressure water pressure to 0.4±0.05MPa.

[0027] Step S107: Control the quenching machine roller speed to 0.25-0.48 m / s.

[0028] Specifically, by reducing the roller speed, the deformation suppression time is prolonged.

[0029] The following is further described by means of specific examples.

[0030] Embodiment: NM450 steel plate with a thickness of 8 mm and a size of the steel plate: 8 mm×2500 mm×6000 mm.

[0031] The quenching process is: the roll gap is set to x+h=13mm, the water ratio is set to 1.3, the total water volume is required to be 2000, and the water volume of the first set of gap nozzles is set to 580m 3 / h, the water volume of the second set of gap nozzles is 450m 3 / h, the high-pressure water pressure reached 0.8MPa, the low-pressure was not used, and the roller speed was set to 0.38m / s.

[0032] After on-site adjustment, the plate shape was slightly buckled when the same water volume was used, and finally the first 580m 3 / h after 450m 3 / h flow setting; when using a water ratio of 1.2, the steel plate has a bow back phenomenon, and finally a water ratio of 1.3 is adopted; when the roller speed is set to 0.4m / s, the tail of the steel plate is slightly warped, and finally the roller speed is reduced to 0.38m / s. Finally, the steel plate does not need to be straightened, and the straightness is measured to be 4mm / 2m, which meets customer needs. It can be directly inspected on the surface and then put into storage for shipment, and it does not need to be put into the furnace for quenching or tempering to relieve stress and straighten again, which reduces production costs and energy consumption.

[0033] Therefore, the technical solution of the present application can control the shape of the tempered plate and improve it to deform in a uniform direction, which is convenient for straightening or meets the straightness requirements of customers without straightening.

[0034] In addition to the above embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A method for adjusting the shape of a thin quenched plate of 10 mm or less, characterized in that: include: Control the angle between the upper nozzle and the upper roller surface of the quenching machine to be equal to the angle between the lower nozzle and the lower roller surface of the quenching machine; The height of the roll gap is set to x+h, where x is the distance between the lower nozzle of the quenching machine and the lower roll surface, and h is the thickness of the steel plate; When the steel plate is quenched, the distance between the upper roller surface and the upper surface of the steel plate is controlled to be 0.

2. The method for adjusting the shape of a thin quenched plate of 10 mm or less according to claim 1, characterized in that: Also includes: Set the water ratio to 1.2~1.

4.

3. The method for adjusting the shape of a thin quenched plate of 10 mm or less according to claim 1, characterized in that: After the water ratio is set to 1.2-1.4, the method further comprises: Determine the minimum value w of the total water volume, and set the water supply volume to w / 2.2~2.

4.

4. The method for adjusting the shape of a thin quenched plate of 10 mm or less according to claim 1, characterized in that: Also includes: Control the high-pressure water pressure to 0.8±0.03MPa, and control the low-pressure water pressure to 0.4±0.05MPa.

5. The method for adjusting the shape of a thin quenched plate of 10 mm or less according to claim 1, characterized in that: Also includes: Control the quenching machine roller speed to 0.25~0.48m / s.

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