Calcium silicon treatment process with calcium cored wire is a mature refining technology. It is widely used in desulfurization, deoxidation, alloying and inclusion denaturation in steel.
The core of the solid calcium wire is a mixture of metal calcium and iron powder, and it is wrapped with cold rolled low-carbon steel strip. Its advantage is that it can be fed to a reasonable depth in molten steel without the mixing problem of calcium iron wire.
The quality of molten steel depends on the quantity and size of non-metallic inclusions that remain in the melt. Incorporating calcium into the molten metal reduces the amount of these inclusions, modifies their shape and composition and thus significantly improves the mechanical properties of the final product.
Moreover, the strong reducing property of calcium makes it possible to reduce the metal oxides that form in the steel. The globular shape of the calcium-bearing inclusions keeps its structure even during hot deformation, eliminating directional anisotropy and ensuring good ductility in all directions.
The cored wire consists of a pure solid calcium inner core wrapped with a cold rolled steel strip. The position of the solid calcium feed point has a significant impact on the amount of calcium absorbed into the molten steel. For optimal results, the feeding point should be situated as close as possible to the center of the molten metal flow and away from the argon blowing circle. This way the calcium is forced to descend into the molten steel, thus increasing its residence time and allowing it to be fully absorbed.
Due to the low density and high reactivity of Ca, it is difficult to introduce it into liquid steel at normal temperatures. Only when it is injected into the steel bath with a core wire can the contact between Ca and the oxygen (O) and sulfur (S) that it is intended to remove be established.
This method enables the calcium to be introduced in the liquid steel at an appropriate time without disturbing the slag-forming process. It also makes it possible to maintain the intimate contact between the metal calcium and molten steel as long as possible and prevents any contaminating reactions.
During the injection process, the core wire must be fed into the steel melt at an appropriate speed. The feeding speed has a significant impact on the absorption rate of the core wire and therefore needs to be carefully controlled. If the feeding speed is too low, the calcium will evaporate before it has been absorbed into the melt.
The conventional method of calcium treatment by adding a ferro-calcium alloy directly into the ladle or spraying calcium powder into the ladle cannot reach the deeper position of the molten steel, and it has a low recovery rate and high cost. The solid pure calcium cored wire developed by our factory overcomes this problem and has a much higher feeding efficiency.
The core wire is made of a pure calcium ingot and wrapped by a cold-rolled steel strip, which makes it easy to control the feeding amount. It can also reduce the consumption of calcium by absorbing it from the slag.
The silicon calcium cored wire is a mature refining technology and is widely used in smelting steel making, such as deoxidation, desulfurization, alloying, microalloying, inclusion denaturation and calcium treatment of continuous casting steel. Anyang Huatuo Metallurgy has three lines of powder wrapped cored wire and two lines of solid cored wire production equipment. If you have any requirements, please feel free to contact us.
Silicon islands on the weld surface are a normal (and unavoidable) byproduct of both solid and metal-cored wires used in gas metal arc welding. When these islands are large enough, they can obstruct the arc and the flow of molten weld metal. This can lead to lack of fusion, poor penetration and inclusions. Metal-cored wires with silicon control technology are designed to help reduce these problems by ensuring that the silicon islands are smaller and easier to see and remove. This helps reduce labor costs and rework time.
Visual inspection of the outer surface of the wires showed that they degraded to different degrees depending on the period and location of storage. For example, on the A wire stored in Gdansk and Warsaw, numerous corrosion precipitates were visible (Fig. 7a). EDS analysis of the precipitates revealed that they mainly consisted of iron oxides. A wire that was stored for a longer period showed many areas where the precipitates merged and covered larger surfaces (Fig. 7b).
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