Application of cored wire technology in casting achieves the following purposes by means of steel ladle metallurgy:

1.    Refining to obtain clean steel of low contents of oxygen and Sulphur;

2.    Adding calcium processing to change the properties of the inclusions;

3.    Adding alloy elements to adjust chemical composition precisely.

Intensifying Final Deoxygenation

Final deoxygenation to intensify molten steel by using wire feeding method is to replace other aluminum adding measures with ladle wire feeding aluminum method to convert dissolved oxygen in steel into aluminium oxide and reduce addition amount greatly whilst stabilizing the content of residue aluminum of steel to a certain quantity. In general, dosage of aluminum is 0.20-0.40kg/t and yield rate achieves 90% to 100%.

Adding Calcium

Adding calcium is to change aluminosilicate formed by aluminium oxide in steel or aluminium deoxidation into liquid calcium aluminate under casting temperature by adding calcium into steel by using cored wire technology (the most is in the form of CaSi alloy) to reduce its quantity, change its shape and downsize it to achieve the purpose of purifying molten steel and improving performance of steel (non-directionality, toughness, machinability and resistance to hydrogen induced cracking). According to different types of steel, 0.15-0.5kg of calcium is generally input into motel steel per ton.

Alloy Composition

When feeding other alloys into molten steel by using cored wire, especially when it is hard to add normally or cannot add steadily, because it is added into the depth of molten steel directly without being exposed to air or slag and it has a large contact area and time with molten steel, not only the addition efficiency is high and the stability is good, but also the addition amount of element can be precisely controlled, fine adjustment of composition within the range of analysis error is available so that it can meet the strict technical requirements and define and control the thermal parameters of the subsequent manufacturing process well. 

• [Editor:张德众]