Chamfered crystallizer narrow-face copper plate for improving cooling strength of bevel of chamfered blank

Abstract

The utility model belongs to the technical field of solidification and continuous casting of steel, and particularly relates to a narrow-face copper plate of a chamfering crystallizer, which is used for improving the cooling strength of an inclined plane of a chamfering blank. A working surface of the narrow-surface copper plate, which is in contact with molten steel, consists of three parts, namely a middle area and chamfering areas on two sides. A protective layer (including an electroplated layer, a spraying layer or a laser cladding layer and the like) is not additionally arranged on the working face of the upper area and the chamfering area of the copper plate, the material of the areas is consistent with that of a copper plate base body, and the height corresponding to the areas is 250-450 mm. The narrow-face copper plate of the chamfering crystallizer is favorable for improving the cooling strength of the inclined face of a chamfering blank and improving the lubricating function of covering slag between the copper plate and a solidification shell, so that the surface quality of a casting blank is improved, and meanwhile the risk that edge breakage occurs to protective layers at the edges and corners of the copper plate can be eliminated.

Description

Technical Field

[0001] The utility model relates to the technical field of steel solidification and continuous casting, in particular to a chamfered crystallizer narrow-face copper plate used for improving the cooling strength of the chamfered billet inclined surface. Background Art

[0002] Transverse cracks at the corners of slabs have long been one of the world's problems that have plagued metallurgical workers. In recent years, chamfered crystallizer technology has become the main control method and research hotspot for transverse cracks at corners, and has been promoted on a large scale at home and abroad. Production practice has found that for chamfered crystallizers with frequent width adjustment operations on the continuous casting line, the corners of the electroplated layer of the narrow copper plate often crack, causing the crystallizer to be offline before its life cycle, which seriously increases production costs. Statistical studies have shown that the location of the cracks mostly occurs in the range of 0 to 200 mm from the meniscus of the crystallizer, corresponding to the range of 0-300 mm from the upper edge of the copper plate. In addition, when the chamfered crystallizer is used to produce peritectic steel grades, the inclined surface of the ingot is prone to scarring. The reason is that after the surface coating has been corroded for a long time by the protective slag in the meniscus area and the steel-water interface, its thermal conductivity deteriorates, resulting in insufficient cooling of the inclined surface of the ingot, and microcracks appear in the ingot shell along the bottom of the vibration mark in the meniscus and nearby areas of the crystallizer.

[0003] Chinese utility model patent No. 201120136707.7 proposes a chamfered crystallizer narrow copper plate with a combined cooling water channel. The patent proposes that the working surface of the copper plate may not have a coating, but does not point out the specific position without the coating, and does not explain the design method of the coating thickness. It cannot solve the problem of corner collapse in a targeted manner, and does not mention how to increase the cooling strength of the chamfered copper plate slope by adjusting the coating.

[0004] To this end, the utility model proposes a chamfered crystallizer narrow surface copper plate for improving the cooling strength of the chamfered blank inclined surface. Utility Model Content

[0005] The principle of the utility model is that in view of the fact that the thermal conductivity of the existing protective layer (including electroplating layer, spraying layer or laser cladding layer, etc.) on the working surface of the copper plate is significantly lower than that of the copper substrate, which easily reduces the thermal conductivity effect. Therefore, through the design of the thickness of the protective layer in different areas, a chamfered crystallizer narrow-face copper plate for improving the cooling strength of the chamfered billet slope is provided, while achieving the goal of eliminating the edge collapse of the corner protective layer and improving the surface quality of the casting billet.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] An embodiment of the utility model provides a chamfered crystallizer narrow copper plate for improving the cooling strength of the chamfered blank inclined surface, the working surface of the copper plate in contact with the molten steel consists of three parts: a middle area and chamfered areas on both sides, in the upper area of ​​the copper plate, no protective layer is added to the working surface of the chamfered area, the protective layer includes an electroplating layer, a spray layer or a laser cladding layer, the material of this area is consistent with the copper plate substrate, and the corresponding height range of this area is 250 to 450 mm.

[0008] Optionally, for the upper region without the protective layer, a protective layer may be added or not added to the working surface of the middle region connected to the chamfered region.

[0009] Optionally, the thickness of the protective layer on the surface of the copper plate can be increased linearly or nonlinearly from top to bottom, and the working surface of the copper plate is smooth and flat as a whole.

[0010] Optionally, the protective layer may not be provided in the middle region, thereby facilitating lubrication between the solidified shell and the copper plate, preventing corrosion and peeling of the protective layer in the meniscus region, and increasing the service life of the copper plate.

[0011] The beneficial effects of the chamfered crystallizer narrow copper plate for improving the cooling strength of the chamfered blank inclined surface according to the embodiment of the utility model include, for example:

[0012] The working surface of the narrow copper plate of the chamfering crystallizer for improving the cooling strength of the chamfered billet slope that contacts the molten steel consists of three parts: the middle area and the chamfered areas on both sides. In the upper area of ​​the copper plate, no protective layer is added to the working surface of the chamfered area. The protective layer includes an electroplating layer, a spraying layer or a laser cladding layer. The material of this area is consistent with the copper plate substrate, and the corresponding height range of this area is 250-450mm. The narrow copper plate of the chamfering crystallizer for improving the cooling strength of the chamfered billet slope achieves the goal of eliminating the edge collapse of the corner protective layer and improving the surface quality of the billet by designing the thickness of the protective layer in different areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 A schematic diagram of the structure of a narrow copper plate of a chamfered crystallizer for improving the cooling strength of the chamfered blank slope provided in this embodiment;

[0015] Figure 2A cross-sectional view of the middle region provided for this embodiment, wherein the shaded portion represents the protective layer;

[0016] Figure 3 This is a cross-sectional view of the chamfered area provided for this embodiment, wherein the shaded portion represents the protective layer.

[0017] Icons: 10-working surface; 11-middle area; 12-chamfering area; 100-narrow copper plate of the chamfered crystallizer used to improve the cooling strength of the chamfered billet slope. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0021] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used. It is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present utility model.

[0022] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0023] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0024] Transverse cracks at the corners of slabs have long been one of the world's problems that have plagued metallurgical workers. In recent years, chamfered crystallizer technology has become the main control method and research hotspot for transverse cracks at corners, and has been promoted on a large scale at home and abroad. Production practice has found that for chamfered crystallizers with frequent width adjustment operations on the continuous casting line, the corners of the electroplated layer of the narrow copper plate often crack, causing the crystallizer to be offline before its life cycle, which seriously increases production costs. Statistical studies have shown that the location of the cracks mostly occurs in the range of 0 to 200 mm from the meniscus of the crystallizer, corresponding to the range of 0-300 mm from the upper edge of the copper plate. In addition, when the chamfered crystallizer is used to produce peritectic steel grades, the inclined surface of the ingot is prone to scarring. The reason is that after the surface coating has been corroded for a long time by the protective slag in the meniscus area and the steel-water interface, its thermal conductivity deteriorates, resulting in insufficient cooling of the inclined surface of the ingot, and microcracks appear in the ingot shell along the bottom of the vibration mark in the meniscus and nearby areas of the crystallizer.

[0025] To this end, the utility model proposes a chamfered crystallizer narrow surface copper plate 100 for improving the cooling strength of the chamfered blank inclined surface.

[0026] Figure 1 The overall three-dimensional structure of the chamfered crystallizer narrow copper plate 100 for improving the cooling strength of the chamfered blank slope is given. Figure 2 and Figure 3 The cross-sectional structure diagram of the chamfered narrow copper plate of the crystallizer and the surface protection layer is given. Figure 1 It can be seen that the working surface 10 of the narrow copper plate in contact with the molten steel consists of three parts: a middle area 11 and chamfered areas 12 on both sides. Figure 2 1 is a schematic diagram of the cross section of the middle area 11. When the thickness of the surface protective layer changes linearly from top to bottom, assuming that the thickness of the protective layer at the upper and lower edges of the copper plate are fixed to X and D (unit: mm), respectively, the total height of the copper plate is H (unit: mm), and the distance from the upper edge of the copper plate is y (unit: mm), then the relationship between the thickness δ of the protective layer in the middle area and y is: δ = (DX) * y / H + X; Figure 3 Schematic diagram of the cross section of the chamfered area 12, in the range of 0 to s (unit: mm) from the upper edge of the copper plate, the thickness of the protective layer is 0 mm, in the range of s to H from the upper edge of the copper plate, the thickness of the protective layer is consistent with the middle area. The range of s value proposed by the utility model patent is 250 to 450 mm.

[0027] Specifically, since the friction between the copper wall and the steel shell is smaller and the copper plate itself has poorer wettability to molten steel, the middle area 11 may not be provided with a protective layer, thereby facilitating lubrication between the solidified shell and the copper plate, while solving the corrosion and peeling problems of the protective layer in the meniscus area and improving the service life of the copper plate.

[0028] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A chamfering mold narrow copper plate for improving the cooling strength of the chamfered billet slope, wherein the working surface (10) of the copper plate in contact with molten steel consists of a middle area (11) and chamfered areas (12) on both sides, and is characterized in that: In the upper area of ​​the copper plate, no protective layer is added on the working surface (10) of the chamfered area (12), and the protective layer includes an electroplating layer, a sprayed layer or a laser cladding layer. The material of this area is consistent with the copper plate substrate, and the corresponding height range of this area is 250 to 450 mm.

2. The chamfered crystallizer narrow surface copper plate for improving the cooling strength of the chamfered blank slope according to claim 1, characterized in that: For the upper region without a protective layer, a protective layer may be added or not added on the working surface (10) of the middle region (11) connected to the chamfered region (12).

3. The chamfered crystallizer narrow surface copper plate for improving the cooling strength of the chamfered blank slope according to claim 1, characterized in that: The thickness of the protective layer on the surface of the copper plate increases linearly or nonlinearly from top to bottom, and the working surface (10) of the copper plate is smooth and flat as a whole.

4. The chamfered crystallizer narrow surface copper plate for improving the cooling strength of the chamfered blank slope according to claim 1, characterized in that: The protective layer is not provided in the middle area (11), thereby facilitating lubrication between the solidified shell and the copper plate, preventing corrosion and peeling of the protective layer in the meniscus area, and improving the service life of the copper plate.

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