Pure calcium cored wire for steelmaking is an excellent deoxidizing agent. It can penetrate steel slag on the surface of liquid steel ladle easily, shorten the time that the pure calcium strip absorbs in the molten steel, reduce the burning loss of metal calcium and improve the absorption efficiency of the calcium addition.
Traditionally, calcium is added to molten steel by spraying or dusting. However, this method has many disadvantages such as high oxidation burning loss rate and low calcium yield. Moreover, it is difficult to control the addition quantity and quality in this way. In order to overcome these problems, a new way of adding calcium has been developed. This is to use a pure solid calcium cored wire.
This wire has a powder additive package (deoxidizer, desulfurization agent and alloy) wrapped in it. During the feeding process, the cored wire will enter a deep portion of the molten steel pool and stay there for a long time. This prevents the oxidation and burning of the additives by air or slag and increases their absorptivity. This way the treatment effect can be achieved more efficiently. Moreover, the use of cored wire also reduces the amount of slag produced and can avoid the nozzle blockage problem. This way, the efficiency of calcium treatment can be significantly improved.
The addition of pure calcium through core wire is widely used in the refining process outside the furnace (cored wire injection) in steelmaking to deeply reduce oxygen (O) and sulfur (S), change the composition of inclusions, prevent caster nozzle clogging of Aluminum killed steel and improve mechanical properties. Due to the low density and low boiling point of Calcium, its efficient use in molten steel requires special addition techniques.
The encapsulated pure metal calcium sheath of the cored wire makes it possible to achieve the abovementioned purposes with high efficiency, and it is also advantageous in terms of costs, consistency and automation.
Inner package raw materials - alloy additives (deoxidizer, desulfurization agent and core powder) are uniformly crushed into the required particle size and then wrapped in a steel sheath by an automatic cored wire machine. The finished alloy cored wire is then wound into coils. During transportation and storage, it is protected with a moisture-proof film or covered with a refractory shrouded nozzle.
Calcium metal has a strong affinity with oxygen and sulfur. It also has low density and a low melting point and boiling point. This makes it difficult to add to liquid steel, and can cause problems like nozzle blockage in continuous casting of aluminum killed-steel. Cored wire can solve these problems by allowing the addition of calcium to occur deep in ladle.
To achieve high calcium recovery, the feed speed of the cored wire needs to be reasonable and the core layer composition must be properly adjusted. In addition, the alloying powder is required to be well bonded with the steel and not leak out of the core. This is why we recommend that the manufacturer use professional cored wire production equipment. Moreover, the quality of the cored wire is largely dependent on technical process parameters such as consistency of the powder metric weight, powder blends and lock seaming. Cored wire can be used for deoxidation, desulfurization, alloying and inclusion denaturation in secondary metallurgy.
Pure calcium has strong affinity with oxygen and sulfur. In the presence of oxygen and sulfur, it can form oxides and oxysulfides CaO and CaS respectively. These can clog the nozzles of the steel melting equipment. During the casting process, they can also cause holes in the metal. Therefore, it is necessary to eliminate them. Cored wire injection is the most efficient way to introduce calcium into liquid steel.
During the casting process, the core wire penetrates into the molten steel and causes chemical reactions. This method helps to avoid the formation of long strips of sulfide inclusions and improves the anisotropy of the metal.
The alloy core wire has the advantage of high penetration into the molten steel and shortens the smelting time. It also reduces the consumption of metallurgy additives, and is highly effective in deoxidation and desulfurization. The alloy can also change the shape of nonmetallic inclusions and improve the quality of molten steel.
English
Write a Message