The present disclosure relates to a steel for pressure vessels used in a hydrogen sulfide atmosphere, and relates to a steel material for pressure vessels having excellent resistance to hydrogen induced cracking (HIC) and a manufacturing method thereof.

A system and method for installing and removing a porous plug relative to a port of metallurgic ladle includes an extendable boom rotatable about vertical axis and pivotable up and down at a first end of the boom. A mast is coupled to a second end of the boom and rotatable about multiple axes relative to the boom to position or maintain the mast in a given orientation, such as in alignment with the port of the ladle in response to rotatable or pivotable movement of the boom. The mast includes a slider mast that is translatable along the length of the mast to insert the plug or retract the plug. The mast may also include jaw grippers to secure the plug and may be configured to rotate the plug relative to the mast. The system may automatically control the position and orientation of the boom, mast, and slider mast.

When performing dephosphorization treatment of hot metal by adding a refining agent as a lime source and an oxygen source (dephosphorizing agent(s) and a gaseous oxygen source into the hot metal accommodated in a hot metal holding container, the refining agent used is a refining agent having an Ig-loss value of from 4.0% by mass to 35.0% by mass and including 60% by mass or more of quicklime.

A method removes phosphorus from a phosphorus-containing substance. In the method, the phosphorus-containing substance that is used as a raw material for metal smelting or refining is reacted with a nitrogen-containing gas so that phosphorus in the phosphorus-containing substance is removed through nitriding. Prior to a treatment of a nitriding removal of phosphorus from the phosphorus-containing substance, a treatment is performed in which the phosphorus-containing substance is heated to an unmolten state temperature range so as to react with a reducing agent, thereby reducing at least a part of metal oxide in the phosphorus-containing substance.

The present disclosure provides a method of making low carbon steel. The method includes tapping the liquid steel out of a primary steelmaking furnace. Deoxidizing the liquid steel. Transferring the deoxidized liquid steel to a ladle metallurgy furnace. Removing sulfur at the ladle metallurgy furnace. Adding fluxes and arcing the liquid steel to prevent sulfur reversion. Transferring the liquid steel from the ladle metallurgy furnace to an RH degasser for carbon removal. The removal of oxygen and sulfur prior to transferring the liquid steel to the RH degasser facilitates nitrogen removal and prevents carbon pick up during the step sulfur removal.

Liquid metal degassing device comprising a chamber containing a liquid metal bath, a device for circulating a gas through a purification chamber and in that the purification chamber comprises a getter material configured to trap dihydrogen from the circulating gas. Method for degassing a liquid metal bath to reduce the hydrogen concentration of the liquid metal comprising the following steps a) Preparing a liquid metal bath, preferably an aluminum alloy b) Circulating a gas, c) Exchanging hydrogen from the circulating gas with the liquid metal such that the hydrogen dissolved in the liquid metal bath diffuses into the circulating gas and enriches the circulating gas with dihydrogen, d) Purifying the circulating gas enriched with dihydrogen in a purification chamber comprising a getter material configured to trap dihydrogen from the circulating gas.

Liquid metal degassing device comprising a chamber containing a liquid metal bath, a device for circulating a gas through a purification chamber and in that the purification chamber comprises a getter material configured to trap dihydrogen from the circulating gas. Method for degassing a liquid metal bath to reduce the hydrogen concentration of the liquid metal comprising the following steps a) Preparing a liquid metal bath, preferably an aluminum alloy b) Circulating a gas, c) Exchanging hydrogen from the circulating gas with the liquid metal such that the hydrogen dissolved in the liquid metal bath diffuses into the circulating gas and enriches the circulating gas with dihydrogen, d) Purifying the circulating gas enriched with dihydrogen in a purification chamber comprising a getter material configured to trap dihydrogen from the circulating gas.

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.