The main products include: square copper mould tube, rectangular copper mould tube, round copper mould tube, H-shaped and other copper mould tube, and mold assembly and technical consulting services
The quality of the copper mould tube has a great influence on the yield and quality of the billeta
It is the only way to improve the working efficiency of continuous caster to increase the service life of copper mould tube.
Through the addition of about 0.1% silver, strength is significantly enhanced with no loss in thermal conductivity.
Cr and Zr precipitation hardening provides this alloy with high strength, high resistance to heat, and thermal conductivity.Special coatings LMM GROUP We use hard chrome plating to increase the life of mould tubes.
The taper of LMM GROUP copper mould tubes developed from single taper to multi-taper, parabola and so on.
The 0.4 ~ 0.5 mm thick ni-co alloy plating layer was added between the inner surface of the copper tube of the mold and the chromium plating layer as a transition layer. Accurate chromium plating Composite copper plating tube. Therefore, the service life of the mold copper tubes is prolonged.
Smelting/Casting: 2 line Smelting furnace and continuous casting machine
Forging/Extrusion: 9 sets Hydraulic Press
23 various units CNC Machines
2 Sets Special CNC Processing Machines
1 line Copper Annealing Furnace
2 lines One electro plating Line for tube and plate each
1 set Tensile Strength Machine
5 sets Harness meters
2 sets Thickness meters
1 set Ultrasonic flaw detection machine
We have complete facilities to process every copper mould tube,galvanize plating, hardness testing to provide accurate Chromium plating to the Mould Tubes to achieve high performance in heat resistance
Smelting/Casting < Forging/Extrusion < Machining < Electro-plating < Quality Assurance
The company strictly according to modern enterprise management requirements set up a perfectquality assurance system, Our Mould Tubes high precision and meet hardness requirement, perfect taper, and coated layer. and passed the ISO9001:2008 quality management system certification,ISO14001:2004 environmental management system certification, OHSAS18001:1999 occupationalhealth and safety management system certification.
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Mould Tubes is a kind of accessories used in cast steel continuous casting machine. The molten steel is directly cast in the copper tube of the crystallizer, and is continuously cooled and formed in the copper tube to pull out the billet.
In the process of steelmaking and continuous casting in steel companies, molten steel must first pass through the mold copper tube at a certain speed to cool and solidify before it can change from liquid to solid.
continuous casting process
It is required that the copper moulds must have the characteristics of wear resistance, high temperature resistance, corrosion resistance, high strength, high hardness, and good heat dissipation. Therefore, the crystallizer copper moulds is composed of bimetal, the base layer is copper (silver copper), and the inner layer is High-performance special metal coating (0.08-0.1 hard chrome or nickel-plated alloy). Nevertheless, the copper mould tube also has a service life, and it must be replaced after a certain amount of excess steel is reached, and the inner layer is worn out.
The shape is curved or straight, and the inner cavity is a single cone, multiple cones or a parabolic surface.
Arc radius: R6m～R15m,
Inner diameter: ∮120mm～∮450mm,
Cooling water working pressure: 0.50MPa～1.20 Mpa
Cooling water velocity: 8m/s～~15m/s
The commonly used taper of single taper copper mould tube is 0.6~0.7%/m, and the maximum taper of 140~150mm billet is 0.9%/m. If the taper is too small, it is easy to cause deviation angle longitudinal cracks, and if the taper is too large, it will increase the drawing resistance and mold wear.
The cavity size is divided into two types: nominal size and actual size. The honorary size is generally named after the cast ring peep grid produced. For example, if a billet of i50mm×150mm is produced, the copper tube is simply referred to as a 150mm copper mould tube.
Copper mould tubes coating material:
At present, the mould tube coating is generally plated with Cr. The hardness of the Cr coating is very high (>HV600), but the thickness is relatively thin (0.06-0.12mm), and it is quickly worn away during use, and the wear resistance of the Cr coating is limited.
Although the hardness of Ni, Ni-Fe, and Co-Ni coatings is lower than that of Cr coatings, the thickness of the coatings can be increased, so the wear resistance and service life of mould tube can be improved. In recent years, it has been widely used on the copper plate of the plate ring crystallizer.
1. mould tubes taper
Since the solidification of the cast slab in the mold is accompanied by volume shrinkage, the inner cavity of the copper plate of the mold must be designed in a shape with a large top and a small bottom, which is the so-called mold taper. Mold taper is divided into width direction and thickness direction.
Taper in the width direction: The taper in the width direction of the mold is more important than the taper in the thickness direction. Therefore, the so-called crystallizer taper refers to the taper in the width direction of the crystallizer.
The shrinkage of the slab is related to the casting speed. Theoretically, the mold taper should change according to the casting speed.
2. Mould tubes width
The setting of the crystallizer width should take into account all the shrinkage from the complete solidification of the liquid steel and cooling to room temperature. According to the composition of the steel and the continuous casting machine and other factors, the total shrinkage is preferably 1.3%~2.5%, and 1.5% for ordinary deep-drawing steel.
3. Cooling intensity of mould tubes
The heat taken away by the billet per unit area per unit time is called cooling intensity. The greater the cooling intensity, the faster the molten steel solidifies, so the casting speed can also be appropriately accelerated.
The factors affecting the cooling strength of the crystallizer are mainly the thermal conductivity of the inner wall of the crystallizer and the flow rate and flow rate of the cooling water in the crystallizer.
4. The material of the Mould tubes
The materials used for the inner wall of the crystallizer mainly include the following four types: copper, copper alloy, copper plate coating, and infiltration layer.
5. The life of the mould tubes
The service life of the crystallizer actually refers to the length of time that the cavity of the crystallizer maintains the original design size and shape. The life of the crystallizer can be expressed by the length of the cast slab poured into the mold; under normal operating conditions, a mold can cast a slab 10,000 to 15,000m long. It is also expressed by the number of furnaces poured from the beginning of use to the repair of the crystallizer. The range is 100~150 furnaces.
6. Copper tubes inner wall thickness
Usually the minimum allowable value of the inner wall of the crystallizer is 6~10mm.
The section of the mold copper tubes must change with the continuous shrinkage of the section of the billet, and the taper of the copper tubes must be appropriate.
Excessive taper will cause the crystallizer to squeeze the slab shell, making it difficult for the drawing and leveling machine to pull the slab, increasing the friction between the slab shell and the inner wall of the mould tube, aggravating the wear of the inner wall of the mould tube, increasing copper on the surface of the slab, and breaking, Accidents such as leakage. Below the meniscus of the copper tube, because the cooling intensity of the corner is greater than that of the face, the corner is the first to leave the inner wall of the crystallizer, and an air gap is formed. Under the action of the air gap in this area, a hot spot will be formed, causing the temperature on the same cross section The gradient is different, and under the action of shrinkage stress, cracks in the billet shell are caused. If the taper is too small, the air gap will increase, the effective heat flow will be less, the billet shell will be thinner, and steel breakout accidents will easily occur.
If the taper is too small, the rotation of the corner will be intensified, and it is easy to induce corner cracks and longitudinal depressions. The reverse taper mainly depends on the section of the billet, the casting speed and the high temperature shrinkage of the steel. Due to the non-uniformity of the air gap thickness and the irregular formation of the longitudinal air gap, the single taper crystallizer cannot completely eliminate the influence of the air gap, which is especially prominent in the production of low carbon peritectic steel. With the development of continuous casting technology, molds with double taper, triple taper, multi taper and parabolic taper have appeared. The parabolic taper mold is more in line with the solidification and contraction shape of the billet shell in the longitudinal direction, thereby eliminating the adverse effects caused by the air gap, increasing the heat transfer effect of the mold, and laying the foundation for efficient continuous casting.
Taper measurement method
There are two ways to express the taper of the copper pipe, one is the taper per meter of length, and the other is the size deviation of the two opposite surfaces of the upper and lower openings of the copper pipe. Some steel mills and copper pipe manufacturers often use the latter taper expression method to measure whether the taper of copper pipes meets the design requirements. Copper pipe taper measurement uses electronic taper measuring instrument and dial indicator. The electronic taper measuring instrument consists of a measuring trolley, a special charger, a portable meter printer and a taper measuring software. The measurement results show the dimensional deviation and the total taper per meter length with a measurement accuracy of 0.01mm. The dial indicator measures the size deviation of the upper and lower ports, and the measurement accuracy is 0.01mm.
1) First connect the measuring trolley, charger and portable meter printer.
2) Lay the copper tube flat, put the measuring trolley into the upper opening of the copper tube, and level the push rod of the trolley.
3) Call out the size of the copper tube to be tested from the portable meter printer, and then adjust to zero.
4) After pressing the “Start” button from the meter head, push the measuring trolley evenly to the lower opening of the copper pipe.
5) Press the “End” button from the meter head, and the printer will print out the taper measurement value to complete the taper measurement of the copper tube.
Practice has proved that defects such as cracks and diamond changes are formed in the finisher, so it is very necessary to check the finisher before pouring:
1. Check whether there is any serious damage on the surface of the copper tube and copper plate in the inner cavity of the finisher.
If the crack at the corner of the slab or the surface scratch depth is greater than 1mm, it must be replaced. At the same time, it is necessary to check whether the cooling water pressure of the crystallizer is normal and there must be no water seepage.
2. Check whether the vibration device of the finisher is operating normally.
3. The corner gap of the inner wall of the combined crystallizer should be less than 0.3mm, and copper gaskets should be used to make the contact plate on the wide and narrow surfaces form an angle of 135° to prevent the continuous casting machine from leaking at the start.
4. Check whether the foot kun at the lower mouth of the crystallizer is rotating. The nozzles at the foot kun and the grid must be complete without clogging. The flat mouth of the flat nozzle should be in the horizontal position.
Q:I have some special requirement about specifications,can you do it?
A:Yes.We have a well-rounded product range, which endows us with the capability of applying many special specifications. Please feel free to contact us with yours.
Q:Do you accept OEM service?
A:Yes, we do.
Q:What is your delivery time?
A:It depends on the size/complexity of your order and our own production schedule. Usually we provide a faster delivery than the industry’s average.
Q:What is the payment term?
A:Our payment terms are negotiable.
Q:Can I have my own logo on the product?
A:Sure, we can apply your own logo on the products according to your drawings
No matter what the use, LMMGROUP offers high-quality mold tube at competitive prices for your next industrial needs project.
We dedicated to research of new technologies, continuously develop various sizes，materials and special shapes, large and super large size mould tubes. Also developed various types of high efficiency copper mould tube for continuous casting machine.
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