C21C7/068

Manufacture of low carbon steel
11047015 · 2021-06-29 · ·

Embodiments include a method of making steel with low carbon content which includes preparing a heat of molten steel composition in a steelmaking furnace to a tapping temperature ranging from 2912 to 3060 degrees F. and tapping into a ladle the molten steel composition having an oxygen level is about 700 to 1000 ppm. The molten steel composition is then transported to a ladle metallurgy furnace, where the molten steel composition is further heated and one or more elements are added to the molten steel composition. The molten steel composition is then transported from the ladle metallurgy furnace to a vacuum tank degasser. The molten steel composition is then decarburized and one or more elements are added to the molten steel composition at the vacuum tank degasser for deoxidization and desulphurization. The molten steel composition is then transported to a ladle metallurgy furnace to further adjust chemistry and temperature.

Non-oriented electrical steel sheet and production method thereof

A steel containing C: not more than 0.0050%, Si: 0.1-5.0%, Mn: 0.02-3.0%, sol. Al: not more than 0.0050%, P: not more than 0.2%, S: not more than 0.0050%, N: not more than 0.0040%, T. Ca: 0.0010-0.0080%, T. O: not more than 0.0100% and having (T. Ca/T. O) of not less than 0.50 but not more than 2.0 by decarburizing to a C content of not more than 0.0050%, adding Si, decreasing Al as much as possible, and adding Ca is melted to form a slab. The slab is subjected to a hot rolling at a coiling temperature of not lower than 550° C., a cold rolling and a finish annealing, or the slab is subjected to a hot rolling, a hot band annealing at a temperature of 900-1150° C., a cold rolling and a finish annealing to thereby produce a non-oriented electrical steel sheet.

Non-oriented electrical steel sheet and production method thereof

A steel containing C: not more than 0.0050%, Si: 0.1-5.0%, Mn: 0.02-3.0%, sol. Al: not more than 0.0050%, P: not more than 0.2%, S: not more than 0.0050%, N: not more than 0.0040%, T. Ca: 0.0010-0.0080%, T. O: not more than 0.0100% and having (T. Ca/T. O) of not less than 0.50 but not more than 2.0 by decarburizing to a C content of not more than 0.0050%, adding Si, decreasing Al as much as possible, and adding Ca is melted to form a slab. The slab is subjected to a hot rolling at a coiling temperature of not lower than 550° C., a cold rolling and a finish annealing, or the slab is subjected to a hot rolling, a hot band annealing at a temperature of 900-1150° C., a cold rolling and a finish annealing to thereby produce a non-oriented electrical steel sheet.

PROCESS FOR INJECTING PARTICULATE MATERIAL INTO A LIQUID METAL BATH
20200385829 · 2020-12-10 ·

The invention relates to a process for injecting particulate material into a liquid metal bath wherein the liquid metal bath contains species to be oxidized, wherein the particulate material is carried to the liquid bath by means of a first gas stream. The solids injection rate is controlled such that the liquid bath temperature and/or the evolution of the liquid bath temperature is maintained within a pre-defined temperature range and the penetration depth of the first gas stream into the liquid bath is controlled by adjusting the flow of the first gas stream. At least one second gas stream is injected into the liquid, wherein the first and the second gas streams are an oxidizing gas, in particular oxygen, and the sum of the gas flows of the first and the second gas streams is determined based on the mass of the species to be oxidized and on the desired time for oxidizing the mass of the species.

PROCESS FOR INJECTING PARTICULATE MATERIAL INTO A LIQUID METAL BATH
20200385829 · 2020-12-10 ·

The invention relates to a process for injecting particulate material into a liquid metal bath wherein the liquid metal bath contains species to be oxidized, wherein the particulate material is carried to the liquid bath by means of a first gas stream. The solids injection rate is controlled such that the liquid bath temperature and/or the evolution of the liquid bath temperature is maintained within a pre-defined temperature range and the penetration depth of the first gas stream into the liquid bath is controlled by adjusting the flow of the first gas stream. At least one second gas stream is injected into the liquid, wherein the first and the second gas streams are an oxidizing gas, in particular oxygen, and the sum of the gas flows of the first and the second gas streams is determined based on the mass of the species to be oxidized and on the desired time for oxidizing the mass of the species.

Fe-Cr-Ni ALLOY AND METHOD FOR PRODUCTION THEREOF

Ti, N, Al, Mg, and Ca concentrations are controlled in order to prevent aggregation of TiN inclusions. Furthermore, not only is a FeCrNi alloy having superior surface property provided, but also a method is proposed in which the FeCrNi alloy is produced at low cost using commonly used equipment. The FeCrNi alloy includes C0.05%, Si: 0.1 to 0.8%, Mn: 0.2 to 0.8%, P0.03%, S0.001%, Ni:16 to 35%, Cr: 18 to 25%, Al: 0.2 to 0.4%, Ti: 0.25 to 0.4%, N0.016%, Mg: 0.0015 to 0.008%, Ca0.005%, O: 0.0002 to 0.005%, freely selected Mo: 0.5 to 2.5% in mass % and Fe and inevitable impurities as the remainder, wherein Ti and N satisfy % N% Ti0.0045 and the number of TiN inclusions not smaller than 5 m is 20 to 200 pieces/cm.sup.2 at a freely selected cross section.

Fe-Cr-Ni ALLOY AND METHOD FOR PRODUCTION THEREOF

Ti, N, Al, Mg, and Ca concentrations are controlled in order to prevent aggregation of TiN inclusions. Furthermore, not only is a FeCrNi alloy having superior surface property provided, but also a method is proposed in which the FeCrNi alloy is produced at low cost using commonly used equipment. The FeCrNi alloy includes C0.05%, Si: 0.1 to 0.8%, Mn: 0.2 to 0.8%, P0.03%, S0.001%, Ni:16 to 35%, Cr: 18 to 25%, Al: 0.2 to 0.4%, Ti: 0.25 to 0.4%, N0.016%, Mg: 0.0015 to 0.008%, Ca0.005%, O: 0.0002 to 0.005%, freely selected Mo: 0.5 to 2.5% in mass % and Fe and inevitable impurities as the remainder, wherein Ti and N satisfy % N% Ti0.0045 and the number of TiN inclusions not smaller than 5 m is 20 to 200 pieces/cm.sup.2 at a freely selected cross section.

CROSS-CORRELATION OF METRICS FOR ANOMALY ROOT CAUSE IDENTIFICATION

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.

Production method for smelting clean steel from full-scrap steel using duplex electric arc furnaces

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.

Production method for smelting clean steel from full-scrap steel using duplex electric arc furnaces

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.