Calcium silicon cored wire is a kind of linear material used in refining molten steel. It is composed of a core powder layer and a sheath made of steel sheet wrapped on the outer surface of the core powder layer.
When in use, the cored wire is continuously fed into the ladle through the wire feeder. When the sheath of the calcium silicate cored wire entering the ladle is melted, the core powder layer is exposed and directly contacts with the liquid steel for chemical reaction. Through the dynamic effect of argon stirring, it can effectively achieve the purposes of deoxidation, desulfurization and removal of inclusions, so as to improve the quality and performance of steel.
The Application of Calcium Silicon Cored Wire
It can be seen that in order to effectively purify the molten steel, the calcium silicate cored wire must meet two conditions:
(1) the active ingredients in the core powder layer must be able to immerse into every corner of the molten steel.
(2) The active ingredients in the core powder layer have enough ability to grab oxygen and sulfur atoms.
Under the existing technology, calcium is a commonly used core powder material. Although it is a strong deoxidizer, its specific gravity is relatively light, its melting point is relatively low, and it is easy to generate bubbles at high temperatures. Therefore, compared with calcium silicate cored wire, if it simply uses metal calcium as the core powder layer of the cored wire, it will appear that the cored wire starts to burn just after being sent into the refining furnace, and the cored wire cannot enter below the middle of the molten steel, The ideal purification effect cannot be achieved. Even if high-temperature-resistant wrapping materials and quick insertion measures are adopted, the combustion of the core powder layer cannot be completely hindered. In this case, the combustion of the core powder layer cannot achieve the ideal purification effect, and at the same time, it will cause a waste of calcium resources with high prices.
What materials are included in calcium silicon core powder?
The calcium silicate cored wire core powder includes the following materials by weight: 18-20 weight parts of silicon, 30-32 weight parts of calcium, 6-8 weight parts of osmium, 6-8 weight parts of sulfur, 5-7 weight parts of iron, 2-4 weight parts of boron, 1-3 weight parts of neodymium, 0.5-1.5 weight parts of lanthanum, 0.05-0.1 weight parts of ytterbium, 0.05-0.1 weight parts of samarium, 0.05-0.1 weight parts of yttrium and 0.005-0.01 weight parts of scandium.
In the process of implementation, 0.5 to 1.5 parts by weight of lanthanum and 0.05 to 0.1 parts by weight of ytterbium. The specific gravity of lanthanum and ytterbium is different, and their sinking rate in molten steel is also different. Ytterbium is heavier, located at the lower end of molten steel, and lanthanum is lighter, located at the upper end of molten steel. This distribution is conducive to deoxidation and desulfurization of molten steel. Not only that, lanthanum and ytterbium can also play a synergistic role with the elements in the above formula to increase their deoxidization and desulfurization capacity for molten steel. Of course, the addition amount of lanthanum and ytterbium should be limited, and improper addition amount will cause negative effects.
And 0.05~0.1 parts by weight of samarium. The specific gravity of samarium is between neodymium and lanthanum, which can help further enhance the deoxidization ability of calcium silicate cored wire powder. At the same time, a small amount of samarium can also improve the toughness and mechanical processing properties of molten steel after solidification. The addition amount of samarium should be limited, and improper addition amount will cause negative effects.
Through the improvement and optimization of the formula of calcium silicate cored wire core powder, a variety of rare earth elements with synergistic effects are introduced, which effectively improves the penetration rate and penetration range of calcium silicate cored wire core powder in molten steel. At the same time, the strong grasping ability of rare earth elements for oxygen and sulfur atoms also improves the ability of calcium silicate cored wire core powder to deoxidize and desulfurize in molten steel. In addition, due to the presence of rare earth elements, The additional amount of calcium silicate cored wire core powder can be far lower than that of ordinary cored wire, which not only saves the production cost but also reduces the dependence on metal, which is conducive to the benign development of ecological resources.
Now, do you know calcium silicon cored wire?