| 摘要 |
<p>PURPOSE: A method for the dephosphorization of high nickel containing molten steel employing AOD is provided to effectively lower phosphorus concentration in molten steel without rephosphorization. CONSTITUTION: The method includes the steps of (i) blending Fe-Ni with steel scraps and then refining the blends in an electric furnace wherein at the point that the terminal temperature of refining process is 1600±20°C, P, S and S in molten steel satisfies:£P|<=0.02%,£S|<=0.008%,£C|<=0.1%; (ii) injection of specific amount of Fe-Si into high Ni concentration molten steel for the purpose of adjusting £Si| after tapping high Ni concentration molten steel from an electric furnace into a ladle, wherein the £Si| in molten steel is regulated between 0.3 and 0.35%; (iii) charging above £Si| adjusted high Ni concentration molten steel into AOD(argon oxygen decarburization); (iv) dephosphorization by lateral injection of oxygen and argon into molten steel in an amount of 0.2-0.6Nm¬3/min/ton·molten steel while injecting fluorite and lime so that high Ni concentration molten steel is conditioned as follows: basicity 3-4, CaO concentration in slag 0-45%, concentration of iron oxides 18-33%; and (v) tapping dephosphorized molten steel into ladle without deoxidation to prevent rephosphorization. The amount of lime to be injected into the molten steel is 30 to 40kg per 1ton-molten steel and further the amount of fluorite to be injected together with the lime is 15-20% of the amount of lime.</p> |
