Technologies are disclosed herein for cross-correlating metrics for anomaly root cause detection. Primary and secondary metrics associated with an anomaly are cross-correlated by first using the derivative of an interpolant of data points of the primary metric to identify a time window for analysis. Impact scores for the secondary metrics can be then be generated by computing the standard deviation of a derivative of data points of the secondary metrics during the identified time window. The impact scores can be utilized to collect data relating to the secondary metrics most likely to have caused the anomaly. Remedial action can then be taken based upon the collected data in order to address the root cause of the anomaly.

A production method for smelting clean steel from full-scrap steel using duplex electric arc furnaces. Electric arc furnaces located in two positions are connected in series, wherein the electric arc furnace in a first position is dephosphorization electric arc furnace, and the electric arc furnace in a second position is a decarbonization electric arc furnace. The production method includes: performing smelting by combining a decarbonization electric arc furnace and 1-3 dephosphorization electric arc furnaces; a specific process of performing the smelting includes: in a charging period of the 1-3 dephosphorization electric arc furnaces, adding the full-scrap steel for the smelting, lime, slag in the decarbonization electric arc furnace, auxiliary materials and carbon powder or a carbon block into the dephosphorization electric arc furnace.

A production method for smelting clean steel from full-scrap steel using duplex electric arc furnaces. Electric arc furnaces located in two positions are connected in series, wherein the electric arc furnace in a first position is dephosphorization electric arc furnace, and the electric arc furnace in a second position is a decarbonization electric arc furnace. The production method includes: performing smelting by combining a decarbonization electric arc furnace and 1-3 dephosphorization electric arc furnaces; a specific process of performing the smelting includes: in a charging period of the 1-3 dephosphorization electric arc furnaces, adding the full-scrap steel for the smelting, lime, slag in the decarbonization electric arc furnace, auxiliary materials and carbon powder or a carbon block into the dephosphorization electric arc furnace.

A molten steel refining method includes throwing a powder to molten steel while heating the powder with a flame formed by combustion of a hydrocarbon gas at the leading end of a top blowing lance. The lance height of the top blowing lance (the distance between the static bath surface of the molten steel and the leading end of the lance) is controlled to 1.0 to 7.0 m, and the dynamic pressure P of a jet flow ejected from the top blowing lance calculated from equation (1) below is controlled to 20.0 kPa or more and 100.0 kPa or less. P=.sub.g U.sup.2/2 . . . (1) wherein P is the dynamic pressure (kPa) of the jet flow at an exit of the top blowing lance, .sub.g the density (kg/Nm.sup.3) of the jet flow, and U the velocity (m/sec) of the jet flow at the exit of the top blowing lance.

A molten steel refining method includes throwing a powder to molten steel while heating the powder with a flame formed by combustion of a hydrocarbon gas at the leading end of a top blowing lance. The lance height of the top blowing lance (the distance between the static bath surface of the molten steel and the leading end of the lance) is controlled to 1.0 to 7.0 m, and the dynamic pressure P of a jet flow ejected from the top blowing lance calculated from equation (1) below is controlled to 20.0 kPa or more and 100.0 kPa or less. P=.sub.g U.sup.2/2 . . . (1) wherein P is the dynamic pressure (kPa) of the jet flow at an exit of the top blowing lance, .sub.g the density (kg/Nm.sup.3) of the jet flow, and U the velocity (m/sec) of the jet flow at the exit of the top blowing lance.

A non-heat treated steel bar according to the present disclosure has a chemical composition consisting of, in mass percent, C: 0.39 to 0.55%, Si: 0.10 to 1.00%, Mn: 0.50 to 1.50%, P: 0.010 to 0.100%, S: 0.040 to 0.130%, Cr: 0.05 to 0.50%, V: 0.05 to 0.40%, Ti: 0.10% to 0.25%, Al: 0.003 to 0.100%, and N: 0.020% or less, with the balance being Fe and impurities, and satisfying Formula (1). A number density of Al.sub.2O.sub.3-based inclusions in each of which Al.sub.2O.sub.3 is contained at 70.0% or more in mass % and AREA is not less than 3 m is 0.05 to 1.00/mm.sup.2.

0.60C+0.2Mn+0.25Cr+0.75V+0.81Mo1.00 (1)

A non-heat treated steel bar according to the present disclosure has a chemical composition consisting of, in mass percent, C: 0.39 to 0.55%, Si: 0.10 to 1.00%, Mn: 0.50 to 1.50%, P: 0.010 to 0.100%, S: 0.040 to 0.130%, Cr: 0.05 to 0.50%, V: 0.05 to 0.40%, Ti: 0.10% to 0.25%, Al: 0.003 to 0.100%, and N: 0.020% or less, with the balance being Fe and impurities, and satisfying Formula (1). A number density of Al.sub.2O.sub.3-based inclusions in each of which Al.sub.2O.sub.3 is contained at 70.0% or more in mass % and AREA is not less than 3 m is 0.05 to 1.00/mm.sup.2.

0.60C+0.2Mn+0.25Cr+0.75V+0.81Mo1.00 (1)

A process for manufacturing a slag conditioning agent for steel desulfurization is shown in which a dried slag material Obtained from a secondary steelmaking process is mixed with quicklime particles. The quicklime particles react with moisture in the slag material to dry the slag material and produce a blend of slag material, hydrated lime and any unreacted quicklime. The blend is then sieved to separate out the hydrated lime. The retained dried fraction after sieving is then mixed with an Al.sub.2O.sub.3 mass fraction from which the slag conditioning agent can be collected. The slag conditioning agent has an equivalent mass ratio which is between 0.55 and 1.5.

A molten iron refining method having, an auxiliary material, and an oxidizing gas supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained/fed in a converter-type vessel, and molten iron is subjected to a refining process. A pre-charged cold iron source is charged into the converter-type vessel at an amount not larger than 0.15 times. A furnace-top-added cold iron source that's part or all of the cold iron source and added from a furnace top is fed during the refining process. A burner at a leading end of the top-blowing lance that spray holes through which a fuel and a combustion-supporting gas are ejected. During the refining process, a powdery auxiliary material processed into powder that's part of the auxiliary material is blown in, to pass through a flame formed by the burner.

A molten iron refining method having, an auxiliary material, and an oxidizing gas supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained/fed in a converter-type vessel, and molten iron is subjected to a refining process. A pre-charged cold iron source is charged into the converter-type vessel at an amount not larger than 0.15 times. A furnace-top-added cold iron source that's part or all of the cold iron source and added from a furnace top is fed during the refining process. A burner at a leading end of the top-blowing lance that spray holes through which a fuel and a combustion-supporting gas are ejected. During the refining process, a powdery auxiliary material processed into powder that's part of the auxiliary material is blown in, to pass through a flame formed by the burner.