Nitrogen sealing device for preventing secondary oxidation in headless continuous casting and rolling
By setting up a nitrogen-sealed box between the descaling box and the F1 finishing mill, the contact between air and the high-temperature intermediate billet is isolated, thus solving the problem of secondary iron oxide scale in the continuous casting and rolling process without end and improving the surface quality of the finished product.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TANGSHAN QUANFENG SHEET CO LTD
- Filing Date
- 2025-07-21
- Publication Date
- 2026-04-28
AI Technical Summary
In the process of continuous casting and rolling without end, especially when producing thin specifications, the high inlet temperature of the finishing mill can easily generate secondary iron oxide scale, which affects product quality and selling price.
A nitrogen-sealed box is installed between the descaling box and the F1 finishing mill. The nitrogen-sealed box isolates the air from the high-temperature intermediate billet, preventing the formation of secondary iron oxide scale.
It effectively prevents the formation of secondary iron oxide scale and improves the surface quality of the finished product.
Smart Images
Figure CN224168336U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a nitrogen sealing device for preventing secondary oxidation in headless continuous casting and rolling, belonging to the field of steel rolling technology in the metallurgical industry. Background Technology
[0002] Headless continuous casting and rolling is a new process for strip steel production in recent years. The high-temperature slab cast from the continuous casting machine enters the No. 1 heating furnace for heating. After being heated in the No. 1 heating furnace, the slab is descaled by the No. 1 descaling machine and then enters the roughing mill for rough rolling. The intermediate slab after rough rolling in the roughing mill enters the No. 2 heating furnace for heating. After being heated in the No. 2 heating furnace, the intermediate slab is descaled by the No. 2 descaling machine and then enters the finishing mill for finishing rolling. After finishing, the strip steel is cooled by laminar flow and then sheared by flying shear. The sheared strip steel enters the coiling unit for coiling.
[0003] In the process of continuous casting and rolling without a head, especially when producing thin-rolled specifications, the inlet temperature of the finishing mill is as high as 1150-1200℃. The high temperature makes it very easy to generate secondary iron oxide scale. After being rolled by the finishing mill, iron oxide defects are easily generated on the surface, which affects the product quality, resulting in second-grade products and directly affecting the product price. Utility Model Content
[0004] The purpose of this invention is to provide a nitrogen sealing device for preventing secondary oxidation in continuous casting and rolling without a head, which can effectively prevent the formation of secondary iron oxide scale when the rolled workpiece enters the finishing mill, improve the surface quality of the finished product, and solve the problems existing in the background technology.
[0005] The technical solution of this utility model is:
[0006] A nitrogen sealing device for preventing secondary oxidation in continuous casting and rolling without a head is provided. The device is installed between the descaling box and the F1 finishing mill and includes a nitrogen sealing box, a nitrogen pipe, an electrically controlled valve, a flow meter, and a nitrogen pipeline. The nitrogen sealing box has an inlet and an outlet at both ends that are compatible with the strip steel. The nitrogen sealing box is connected to the nitrogen pipeline through the nitrogen pipe and the nitrogen pipeline. The electrically controlled valve and the flow meter are installed on the nitrogen pipeline.
[0007] The nitrogen sealing box is a rectangular box whose length matches the distance between the descaling box and the F1 finishing mill.
[0008] The nitrogen sealing box is a rectangular sealing box consisting of an upper cover plate, four side baffles and a bottom plate. The box is equipped with a conveyor roller that works with the strip steel.
[0009] The nitrogen gas pipeline consists of two lines, which are respectively connected to the top of the nitrogen-sealed box on both sides.
[0010] The beneficial effects of this utility model are: by setting a nitrogen-sealed box in the area between the fine descaling box and the F1 rolling mill, and filling it with nitrogen to seal it, the contact between air and high-temperature intermediate billet is isolated, effectively preventing the formation of secondary iron oxide scale after fine descaling, and greatly improving the surface quality of the finished product. Attached Figure Description
[0011] Figure 1 This is the front view of the present utility model;
[0012] Figure 2 This is a top view of the present invention;
[0013] In the diagram: 1. Nitrogen sealing box; 2. Nitrogen pipe; 3. Fine descaling box; 4. Electrically controlled valve; 5. Flow meter; 6. Nitrogen pipeline; 7. F1 finishing mill; 8. Strip steel; 9. Oxygen meter. Detailed Implementation
[0014] The present invention will be further described below with reference to the accompanying drawings and examples.
[0015] See attached document Figure 1-2 A nitrogen sealing device for preventing secondary oxidation in continuous casting and rolling without a head is provided. The device is located between the descaling box 3 and the F1 finishing mill 7. It includes a nitrogen sealing box 1, a nitrogen pipe 2, an electrically controlled valve 4, a flow meter 5, and a nitrogen pipeline 6. The nitrogen sealing box 1 has an inlet and an outlet at both ends that are respectively matched with the strip steel 8. The nitrogen sealing box 1 is connected to the nitrogen pipe 2 and the nitrogen pipeline 6. The electrically controlled valve 4 and the flow meter 5 are installed on the nitrogen pipeline 6.
[0016] In this example, refer to the appendix. Figure 1-2 The nitrogen sealing box 1 is a rectangular sealing box consisting of an upper cover plate, four side baffles and a bottom plate. It is 3000mm long, 900mm high and 1500mm wide. It is set between the descaling box 3 and the F1 finishing mill 7. The F1 finishing mill 7 is the first mill of the finishing mill group. The box includes a conveyor roller table that cooperates with the intermediate billet.
[0017] On both sides of the top of the operating side, a nitrogen pipe 2 is introduced to connect with the nitrogen sealing box 1 for blowing in nitrogen. In actual use, an oxygen meter detection instrument 9 and an electronically controlled valve 4 are added to form a closed-loop control.
[0018] By sealing the area between the descaling box 3 and the F1 finishing mill 7 with nitrogen, the contact between oxygen in the air and the high-temperature intermediate billet is reduced, effectively preventing the formation of secondary iron oxide scale after descaling and greatly improving the surface quality of the finished product.
Claims
1. A nitrogen sealing device for preventing secondary oxidation in headless continuous casting and rolling, characterized in that: The device is located between the descaling box (3) and the F1 finishing mill (7), and includes a nitrogen sealing box (1), a nitrogen pipe (2), an electrically controlled valve (4), a flow meter (5) and a nitrogen pipeline (6). The nitrogen sealing box (1) has an inlet and an outlet at both ends that are compatible with the strip (8). The nitrogen sealing box (1) is connected to the nitrogen pipeline (6) through the nitrogen pipe (2). The nitrogen pipeline (6) is equipped with an electrically controlled valve (4) and a flow meter (5).
2. The nitrogen sealing device for preventing secondary oxidation in headless continuous casting and rolling according to claim 1, characterized in that: The nitrogen sealing box (1) is a rectangular box whose length matches the distance between the descaling box (3) and the F1 finishing mill (7).
3. The nitrogen sealing device for preventing secondary oxidation in headless continuous casting and rolling according to claim 2, characterized in that: The nitrogen sealing box (1) is a rectangular sealing box consisting of an upper cover plate, four side baffles and a bottom plate. The box is equipped with a conveyor roller that works with the strip steel.
4. The nitrogen sealing device for preventing secondary oxidation in headless continuous casting and rolling according to claim 1, characterized in that: The nitrogen pipe (2) consists of two lines, which are respectively connected to the top two sides of the nitrogen sealing box (1).