A small square billet tubular crystallizer that effectively reduces squareness
By designing a square cavity structure with multi-taper segments, the inner cavity of the copper tube of the small square tube crystallizer is optimized, and the problem of casting blank desquamation at high pull speed is solved, which significantly improves the quality of the casting blank and the uniformity of the blank shell, and reduces the Desquamation rate.
Patent Information
- Application Number
- CN201910005058.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-01-03
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2039-01-03
AI Technical Summary
At this stage, the casting quality of small square tube crystallizers has decreased at high pull speed, especially the desquamation defects have increased significantly. The existing copper tube cavity taper curve design cannot meet the conditions of efficient continuous casting, which affects heat transfer and uniform blank shell Grow.
A crystallizer copper tube cavity with a square cavity structure is designed, including multiple tapered segments with a taper range from 3.5% to 0.3%/m. The copper tube cavity is optimized through an integrated direct and arc transition. Shape to reduce air gap and improve contact density of the blank shell.
Under the same process conditions, the desquamation rate of the casting billet was significantly reduced, from 0.09% to 0.028%, which improved the quality of the casting billet, which was in line with the shrinkage law of water solidification at high pull speed, ensuring uniform growth of the blank shell and reduced air gap.
Smart Images
Figure CN109513889B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a crystallizer, in particular to a small square billet tubular crystallizer which effectively reduces de-squareness, and belongs to the technical field of crystallizers. Background Art
[0002] With the rapid development of my country's steel technology, continuous casting technology is also moving towards a high-efficiency trend. The key technology of efficient continuous casting is to make the high-temperature molten steel form a billet shell of a certain thickness and strength in a very short time when passing through the inner cavity of the crystallizer to resist the static pressure of the molten steel and ensure the smoothness of continuous casting. The core of efficient continuous casting is the crystallizer, and the design and optimization of the taper curve of the inner cavity of the crystallizer are particularly prominent. In order to adapt to the shrinkage deformation of the billet in the crystallizer and the thermal deformation of the crystallizer itself, the inner cavity of the crystallizer has a taper, which is large at the top and small at the bottom, so as to reduce the air gap thickness, improve cooling conditions, and improve the drawing speed and product quality. If the taper is too small, the air gap thickness is large, which affects the heat transfer of the crystallizer and restricts the increase in the billet drawing speed. If the taper is too large, the billet drawing resistance is large, which aggravates the wear of the crystallizer and may even break the billet and cause steel leakage accidents. At present, after the drawing speed is increased, the quality of the billet is significantly reduced, especially the defects of small square billets are significantly increased. The taper curve design of the inner cavity of the crystallizer copper tube cannot meet the needs of the existing process conditions. In view of this situation, the taper curve of the crystallizer copper tube needs to be redesigned. Summary of the invention
[0003] To solve the above problems, the present invention proposes a small square billet tubular crystallizer which can effectively reduce de-squareness, develops and designs the taper curve of the inner cavity of the crystallizer copper tube, controls the de-squareness of the small square billet casting, and solves the de-squareness problem of the casting.
[0004] The invention discloses a small square billet tube crystallizer which can effectively reduce de-squareness, comprising a cavity which is integrally formed by two groups of opposite surfaces and has a square cross-section; one group of opposite surfaces of the cavity is a straight surface, and the other opposite surface is a curved surface, and the straight surface and the curved surface include a first tapered section, a second tapered section, a third tapered section, a fourth tapered section and a fifth tapered section which are integrally formed; the first tapered section is located at 0 to 250 mm, and its taper range is 3.5 to 6.5% / m; the second tapered section is located at 250 to 450 mm, and its taper range is 2.0 to 3.0%) / m; the third tapered section is located at 450 to 500 mm, and its taper range is 1.0 to 2.0%) / m; the fourth tapered section is located at 450 to 500 mm, and its taper range is 2.0 to 3.0%) / m; the fifth tapered section is located at 450 to 500 mm, and its taper range is 3.5 to 6.5%) / m; the fifth ...2.0 to 3.0%) / m; the fifth tapered section is located at 450 to 500 mm, and its taper range is 2.0 to 3.0%) / m; the fifth tapered section is located at 450 to 500 mm, and its tap ~650mm, taper range 1.0~1.5)% / m; the fourth taper section position is 650~850mm, taper range 0.5~0.8% / m; the fifth taper section position is 850~900mm, taper range 0.1~0.3% / m; in the actual application process, under the same drawing speed conditions, the defect of billet de-squareness is significantly reduced, which conforms to the solidification shrinkage law of molten steel in the crystallizer under the existing high drawing speed. The contact between the billet shell and the copper tube is closer, the air gap is reduced, and the billet shell grows evenly, which can well solve the quality problem of small square billet de-squareness under high drawing speed.
[0005] As a preferred embodiment, adjacent straight surfaces and curved surfaces are transitioned by rounded corners.
[0006] As a preferred embodiment, the width and height of the cavity are 120×120mm~165×165mm, the length of the cavity is 850~950mm, the end of the cavity close to the first tapered section is the upper opening of the crystallizer, and the end of the cavity close to the fifth tapered section is the lower opening of the crystallizer.
[0007] Compared with the prior art, the present invention has a small square billet tubular crystallizer which effectively reduces de-squareness; in an actual production process, under the same process conditions, the quality of the billet is greatly improved, and the de-squareness rate of the billet is reduced from 0.09% to 0.028%. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 It is a schematic diagram of the radial cross-section structure of the present invention.
[0009] Figure 2 It is a schematic diagram of the overall structure of the present invention. DETAILED DESCRIPTION
[0010] Embodiment 1:
[0011] like Figure 1 The small square billet tubular crystallizer shown in the figure is effective in reducing de-squareness, comprising a cavity 1 which is made of two sets of opposite surfaces in one piece and has a square cross-section; one set of opposite surfaces of the cavity 1 is a straight surface 2, and the other opposite surface is a curved surface 3, and the straight surface 2 and the curved surface 3 include a first tapered section 4, a second tapered section 5, a third tapered section 6, a fourth tapered section 7 and a fifth tapered section 8 which are made in one piece; the first tapered section 4 is located at 0 to 250 mm, and its taper range is 3.5 to 6.5% / m; the second tapered section 5 is located at 250 to 450 mm, and its taper range is 2.0 to 3.0%) / m; the third tapered section 6 is located at 100 to 250 mm, and its taper range is 10 to 250% / m; the third tapered section 7 is located at 250 to 450 mm, and its taper range is 2.0 to 3.0%) / m; the third tapered section 8 is located at 100 to 250 mm, and its taper range is 10 to 250% / m. The position of the fourth tapered section 7 is 650-850mm, and the taper range is 0.5-0.8% / m; the position of the fifth tapered section 8 is 850-900mm, and the taper range is 0.1-0.3% / m. In the actual application process, under the same drawing speed, the defect of billet de-squareness is significantly reduced, which conforms to the solidification and shrinkage law of molten steel in the crystallizer under the existing high drawing speed. The contact between the billet shell and the copper tube is closer, the air gap is reduced, and the billet shell grows evenly, which can well solve the quality problem of small square billet de-squareness under high drawing speed.
[0012] In yet another embodiment, the adjacent straight surfaces 2 and curved surfaces 3 are transitioned by rounded corners.
[0013] In another embodiment, the width and height of the cavity 1 are 120×120mm~165×165mm, the length of the cavity 1 is 850~950mm, the end of the cavity 1 close to the first tapered section 4 is the upper opening of the crystallizer, and the end of the cavity 1 close to the fifth tapered section 8 is the lower opening of the crystallizer.
[0014] The above embodiments are only preferred implementations of the present invention, so all equivalent changes or modifications made according to the structures, features and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.
Claims
1. A small square billet tubular crystallizer which effectively reduces de-squareness, characterized in that: The invention comprises a cavity which is integrally formed by two groups of opposite surfaces and has a square cross-section; one group of opposite surfaces of the cavity is a straight surface, and the other opposite surface is a curved surface; the straight surface and the curved surface include a first tapered section, a second tapered section, a third tapered section, a fourth tapered section and a fifth tapered section which are integrally formed; the first tapered section is located at 0 to 250 mm, and its taper range is 3.5 to 6.5% / m; the second tapered section is located at 250 to 450 mm, and its taper range is 2.0 to 3.0% / m; the third tapered section is located at 450 to 650 mm, and its taper range is 1.0 to 1.5% / m; the fourth tapered section is located at 650 to 850 mm, and its taper range is 0.5 to 0.8% / m; the fifth tapered section is located at 850 to 900 mm, and its taper range is 0.1 to 0.3% / m; The adjacent straight surfaces and curved surfaces are transitioned by rounded corners; The width and height of the cavity are 120×120mm~165×165mm, the length of the cavity is 850~950mm, the end of the cavity close to the first tapered section is the upper opening of the crystallizer, and the end of the cavity close to the fifth tapered section is the lower opening of the crystallizer.