In the process of steelmaking and continuous casting of steel companies, molten steel must first pass through the crystallizer copper tube to exothermic cooling and solidification at a certain speed before it can change from liquid to solid.
With competitive price and timely delivery, SINOMETAL sincerely hope to be your supplier and partner.
To provide mould tubes with optimal physical and mechanical properties to customers’ specifications, mould tube products are supplied of the following materials:
These materials have different levels of hardness and thermal conductivities. We are highly experienced in choosing proper materials to meet the specific demands in heat resistance and thermal conductivities of customers’ applications. The physical and mechanical properties of these materials are compared in details in the following tables:
Material
Cu-DHP
Cu-Ag
Cu-Cr-Zr
Melting point
℃
℃
℃
Coefficient of thermal expansion at 20℃
1.68×10-5
1.68×10-5
1.70×10-5
Thermal
340 W/(m·K)
377 W/(m·K)
325 W/(m·K)
Recrystallization
330℃
370℃
700℃
Hardness at 20℃
Min. 85 HB
For more ccm mould tubeinformation, please contact us. We will provide professional answers.
Min. 90HB
Min. 120HB
The Taper of Copper Moulds is of vital importance to the performance and life.
We supply Copper Moulds of best suitable tapers and stronger anti-wearing plating for copper mould tubes and mould plates.
Ranging from Single Taper, Double Taper, Triple Taper to Multiple Taper we supply all variants.
Each mould taper is tested by the computer-operated taper monitor and the taper graph for each mould tube is delivered along with mould tubes.
Nevertheless, the mold also has a service life, reaching a certain amount of steel, and the inner layer must be replaced after wear.
Although there are some companies that repair and rebuild or trade in copper pipes that are replaced during use, they are all repairs in the traditional sense, and they are plated with the original metal material – hard chrome. It has no practical significance to completely change the performance of copper pipes, increase the amount of steel passing through, and reduce costs.
The copper mould tube is a continuous steel casting equipment that receives the molten steel injected from the intermediate tank and solidifies it into a solid billet shell according to the specified cross-sectional shape. It is the most critical component of the continuous casting machine. Its structure, material and performance parameters play a decisive role in the quality of the billet and the production capacity of the casting machine. There are many types of copper mould tubes on the market. According to the taper of the copper mould tube, there are single-taper CMTs, multi-taper CMTs and continuous-taper CMTs.
The taper of the inner wall of the single-taper copper mould tube is a single constant value, but the shrinkage deformation of the billet during the continuous casting process is not a linear process, so the single-taper copper mould tube has certain defects and is not suitable for large-scale application in actual production.
The continuous casting machine with multiple tapers or continuous tapers can better adapt to the shrinkage deformation of molten steel during production. In recent years, many domestic and foreign researchers have done a lot of research on the taper of the copper mould tube. It is generally believed that the solidification shrinkage of high-temperature molten steel conforms to the square root change, so it is believed that designing the taper of the CMT as a parabola should be the most appropriate. So far, the following optimized copper mould tube with continuous tapers have been developed at home and abroad:
As the name suggests, the funnel-shaped copper mould tube is a CMT that looks like a funnel in appearance. The shape of the original vertical bending-shaped copper mould tube is a vertical section in the upper half, an arc in the lower part, and the side panels can be adjusted. The designers of the Arvedi plant changed the cross-sectional shape of the upper mouth to the shape of a funnel. The modified copper mould tube has a vertical shape in the upper half and then connects with the arc section in the lower part. The improved new funnel-like shape occupies about 80% of the total length of the CMT, which occupies a very large proportion.
The funnel-shaped copper mould tube changes the situation of the traditional CMT being the same in any cross-section. When cooling in the copper mould tube, the thickness and shape of the billet will gradually decrease. However, during the continuous casting process, the billet will shrink and deform during solidification, especially during the continuous casting process, the billet will have many surface defects. Therefore, the original intention of the research and design of this type of copper mould tube is to reduce the deformation rate of the two-phase zone, so that the deformation rate of the solid-liquid zone is less than the set critical value when the solidification shrinkage occurs in the billet.
The advantage of the H2 copper mould tube process is that the internal space of the tube produced by it is very large, which can make the high-temperature molten steel flow large, and at the same time, it has a natural deceleration effect.
The H2 copper mould tube has a bulging shape that passes through the entire tube from top to bottom and then continues to a certain position in the middle before it ends. Because the H2 CMT has a bulging shape, in order to straighten the bulging shape of the continuous casting billet, a set of rollers is designed and added at the outlet. The length of this set of rollers is twice as long as the length without the straightening roller, so the stress on the billet shell will be much reduced.
Secondly, when the internal space of the H2 copper mould tube cavity is increased, more molten steel can be introduced into the tube for cooling during continuous casting production. The increase in the internal space of the tube will also lead to the increase in the size of the crystallizer, making the inlet and outlet design of the cooling water more in line with the actual production needs, ensuring that the liquid steel level does not fluctuate greatly, reducing friction resistance, cracks, and surface defects of the ingot.
The inlet and outlet of the parallel plate straight copper mould tube are relatively flat, and the high-temperature liquid steel to be injected into the tube can flow out from both sides.
The cross-section of the inner cavity of the copper tube of this type of CMT is rectangular. In the initial stage of continuous casting cooling, the billet shell is relatively thin and may deform, causing production defects in the billet. The use of this type of mould tube can avoid this situation. In each coordinate position of the inner cavity of the tube, the liquid metal can be continuously cooled during continuous casting production to form a billet with consistent thickness.
The cross-sectional shape of the inner cavity of the convex copper mould tube is different from that of the previous mould tube. The inner wall of the uppermost part of the CMT is convex from the inside to the outside, and the angle between the two adjacent walls of the tube cavity is an obtuse angle, which is generally 96°. Then it slowly transitions downward to a plane, and the angle between the two adjacent walls of the tube cavity gradually decreases to the most common 90°. Then, as the continuous casting process proceeds, the temperature of the billet gradually decreases due to the cooling effect of the billet, and the convex billet shell shrinks and deforms and gradually becomes a rectangular surface. The cross-sectional shape change of the inner wall of the copper tube should be consistent with the law of the shrinkage deformation of the billet, so that the inner wall of the copper mould tube can have good continuous contact with the outer surface of the billet shell, reducing the generation of air gaps and making the heat transfer process better. The billet shell at the corner of the billet can change evenly like the billet shell at other positions. Therefore, the billet shell at the corner of the billet can have a certain strength to reduce steel leakage and crack defects on the surface and inside of the billet.
The benefit of using a convex copper mould tube is that it can increase the production speed of the ingot by more than 50%, and at the same time, the quality of the ingot produced has also been greatly changed. However, the convex crystallizer also has its own disadvantages: although the convex tube reduces the air gap so that there is good contact between the ingot and the inner wall of the copper tube, it will aggravate the surface deformation of the ingot when it leaves the mould tube(the shrinkage in the middle of the ingot is less than that in the corner area, resulting in a deformation defect of the ingot with a convex middle). After the occurrence of this surface deformation defect, it will bring certain difficulties to the subsequent production cooling process of the ingot, increase the cost of the production process, and reduce production efficiency.
The shape of the diamond copper mould tube is closer to the shape of a diamond when looking down from the top of the tube, so it is called a diamond copper mould tube.
This CMT is different from other types of CMTs in shape and length. For example:
(1) The length of the copper tube can be increased by 100mm-200mm on the original basis, so that the continuous casting production time of the ingot in the tube can be increased, making the solidification thickness of the ingot thicker.
(2) A parabolic taper with a larger taper than the previous copper mould tube is selected. This design can ensure that the shell of the ingot can change evenly.
(3) Starting from 300 mm~400 mm below the upper mouth of the copper mould tube and continuing to the outlet of the diamond tube, the taper of the corner part of the copper tube is smaller than the taper of the middle position or there is no taper. This method is used to reduce the wear of the corner position. The middle part of the copper tube is still selected with a parabolic taper.