The application of cored wire technology in casting is mainly through ladle metallurgy to achieve the following purposes:
1. Refining to obtain clean steel with low oxygen and sulfur content;
2. Give calcium treatment to change the characteristics of inclusions;
3. Add alloying elements to precisely adjust the chemical composition of molten steel.
Using wire feeding method to strengthen the final deoxidation process of molten steel is to use ladle feeding alu wire to replace other adding aluminum measures after tapping of molten steel, so as to achieve the transformation of dissolved oxygen in the steel into alumina. And while the residual aluminum content of the steel is stabilized at a certain order of magnitude, the amount of aluminum added is greatly reduced. Under normal circumstances, the amount of aluminum is 0.20-0.40kg/t, and the yield is 90%-100%.
Its main task is to use cored wire technology to add calcium (mostly in the form of CaSi cored wire) to steel. The aluminum oxide in the steel and the aluminosilicate formed when aluminum is deoxidized are transformed into calcium aluminate that is liquid at the pouring temperature, thereby reducing its quantity, changing its shape, and reducing its size. Finally, the purpose of purifying molten steel and improving the properties of steel (anisotropy, toughness, machinability, and resistance to hydrogen-induced cracking, etc.) is achieved. According to the different types of steels, 0.15-0.5kg calcium is generally added to each ton of molten steel.
When using cored wire to feed other alloying elements to molten steel, especially when it is difficult to add normally or the addition is unstable, because it can be directly added to the depth of molten steel without contact with air and slag, and make it under higher pressure, and it has a larger contact area and time with molten steel. Therefore, not only the addition efficiency is high, the results are stable, but the addition amount of the elements can be accurately controlled, and the composition can be fine-tuned within the range of analysis error. Thus, it can meet the strict technical requirements for use, and better regulate and control the heat treatment parameters of the subsequent manufacturing process.