The present invention discloses a wire rod for an ultrahigh-strength steel cord and a manufacturing method thereof. The manufacturing method includes: smelting molten steel where inclusions in sizes ≥5 μm are at a number density ≤0.5/mm.sup.2 and sizes of inclusions are ≤30 μm; casting the molten steel into an ingot blank with a center carbon segregation value of 0.92-1.08; cogging the ingot blank into an intermediate blank with a center carbon segregation value of 0.95-1.05; rolling the intermediate blank into a wire rod; and performing temperature control cooling on the wire rod to obtain a wire rod with high purity, high homogeneity and tensile strength ≤1,150 MPa. The wire rod may be used for an ultrahigh-strength steel cord with single tensile strength ≥3,600 MPa.

A decarburization end point determination method includes: estimating the carbon concentration and oxygen concentration of the molten steel and carbon dioxide gas concentration of exhaust gas in the vacuum chamber by using measurement values of the carbon concentration and the oxygen concentration of the molten steel, a measurement value of internal pressure of the vacuum chamber, and a model formula; correcting a parameter included in the model formula to reduce at least one of a difference between an estimate value and a measurement value of the oxygen concentration and a difference between an estimate value and a measurement value of the carbon dioxide gas concentration of the exhaust gas; estimating the carbon concentration of the molten steel by using the model formula in which the parameter is corrected; and determining timing when an estimate value reaches a target value as the completion time point of the vacuum decarburization treatment.

A decarburization end point determination method includes: estimating the carbon concentration and oxygen concentration of the molten steel and carbon dioxide gas concentration of exhaust gas in the vacuum chamber by using measurement values of the carbon concentration and the oxygen concentration of the molten steel, a measurement value of internal pressure of the vacuum chamber, and a model formula; correcting a parameter included in the model formula to reduce at least one of a difference between an estimate value and a measurement value of the oxygen concentration and a difference between an estimate value and a measurement value of the carbon dioxide gas concentration of the exhaust gas; estimating the carbon concentration of the molten steel by using the model formula in which the parameter is corrected; and determining timing when an estimate value reaches a target value as the completion time point of the vacuum decarburization treatment.

A steel consists of, in mass %, C: 0.25 to 0.45%, Si: 0.10 to 0.50%, Mn: 0.40 to 0.70%, P: 0.015% or less, S: 0.005% or less, Cr: 0.80 to 1.50%, Mo: 0.17 to 0.30%, V: 0.24 to 0.40%, Al: 0.005 to 0.100%, N: 0.0300% or less, O: 0.0015% or less, and the balance being Fe and impurities, and satisfies Formula (1) to Formula (4) described in the present specification, wherein: its microstructure is composed of ferrite and pearlite having a total area fraction of 5.0 to 100.0%, and a hard phase having a total area fraction of 0 to 95.0%; a proportion of a total area of CaO—CaS—MgO—Al.sub.2O.sub.3 composite oxides with respect to a total area of oxides in the steel is 30.0% or more; and a number density of oxides having an equivalent circle diameter of 20.0 μm or more is 15.0 pieces/mm.sup.2 or less.

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.

The stainless steel contains 0.0001 mass % or more and 0.15 mass % or less of C, 0.30 mass % or more and 2.0 mass % or less of Si, 0.1 mass % or more and 15 mass % or less of Mn, 5 mass % or more and 30 mass % or less of Ni, 0.0001 mass % or more and 0.01 mass % or less of S, 16 mass % or more and 25 mass % or less of Cr, 0 mass % or more and 5 mass % or less of Mo, 0 mass % or more and 0.005 mass % or less of Al, 0 mass % or more and 0.0010 mass % or less of Mg, 0.0010 mass % or more and 0.0060 mass % or less of 0, and 0.0001 mass % or more and 0.5 mass % or less of N, and at least includes an inclusion with an equivalent circle diameter of 5 μm or more, having the average composition of 5 mass % or more of MnO, 20 mass % or more of Cr.sub.2O.sub.3+Al.sub.2O.sub.3, 1 mass % or more of Al.sub.2O.sub.3, and 5 mass % or less of Ca0. The number density of the inclusion having the composition is 0.5 inclusions/mm.sup.2 or less.

A high-performance Nd—Fe—B isotropic magnetic powder and a preparation method thereof are disclosed. The method includes S1, smelting and refining ingredients under vacuum to obtain an alloy ingot, crushing the alloy ingot to obtain an alloy block, wherein the smelting is conducted at a temperature of 1,350-1,450° C., and the refining is conducted at a temperature of 1,335-1,430° C. and a pressure of 900-1,100 Pa in an inert gas atmosphere for 3-7 minutes; S2, melting the alloy block obtained in step S1 to obtain an alloy solution, rapidly quenching the alloy solution to form a Nd—Fe—B rapidly-quenched alloy plate; S3, crushing the Nd—Fe—B rapidly-quenched alloy plate obtained in step S2 to obtain a magnetic powder; S4, subjecting the magnetic powder to a crystallization heat treatment in an inert gas atmosphere, and cooling to obtain the Nd—Fe—B isotropic magnetic powder.

There is provided a carburized bearing that is excellent in rolling contact fatigue life with a change in structure under a hydrogen-generating environment. In the carburized bearing, a chemical composition of a core portion consists of, in mass %, C: 0.25 to 0.45%, Si: 0.10 to 0.50 %, Mn: 0.40 to 0.70 %, P: 0.015% or less, S: 0.005% or less, Cr: 0.80 to 1.50%, Mo: 0.17 to 0.30%, V: 0.24 to 0.40%. Al: 0.005 to 0.100%, N: 0.0300% or less, O: 0.0015% or less, and the balance being Fe and impurities, and satisfies Formula (1) to Formula (4) described in the present specification. A proportion of a total area of CaO—CaS—MgO—Al.sub.2O.sub.3 composite oxides with respect to a total area of oxides in the carburized leaping is 30.0% or more, and a number density of oxides having an equivalent circle diameter of 20.0 μm or more is 15.0 pieces/mm.sup.2or less.

A dual-phase stainless steel or dual-phase stainless steel seamless pipe has a certain composition, the dual-phase stainless steel or dual-phase stainless steel seamless pipe having a microstructure containing 20 to 70% austenitic phase and 30 to 80% ferritic phase by volume, the dual-phase stainless steel or dual-phase stainless steel seamless pipe having a yield strength, YS, of 448 MPa or more, and containing oxide inclusions of which oxide inclusions having an average particle diameter of 1 μm or more have a number density of 15/mm.sup.2 or less, and at most 50 mass % of the oxide inclusions having an average particle diameter of 1 μm or more are oxide inclusions containing aluminum.

A decarburization refining method for molten steel under reduced pressure. The method includes an oxygen-blowing decarburization and a rimmed decarburization. Using operation data taken at a time when oxygen-blowing decarburization is started and a time when oxygen-blowing decarburization is ended, an amount of carbon removed while the oxygen-blowing decarburization is performed is estimated. Based on the estimated amount of carbon removed, a carbon concentration in molten steel at a time when the rimmed decarburization is started is estimated. Using the estimated value as the carbon concentration in molten steel at the time when the rimmed decarburization is started, a change over time in the carbon concentration in molten steel while the rimmed decarburization is performed is calculated. Based on the calculated change over time in the carbon concentration in molten steel while the rimmed decarburization is performed, a determination is made about a time when the rimmed decarburization is ended.