C23C2/0222

GALVANIZED STEEL SHEET FOR HOT PRESSING AND METHOD FOR PRODUCING HOT PRESSED MOLDED ARTICLE

To provide a galvanized steel sheet for hot pressing which can achieve heating for suppressing the occurrence of LME cracks in a short time during a hot pressing process, and a method of manufacturing a hot press-formed product obtained by performing hot pressing using the galvanized steel sheet. Disclosed is a galvanized steel sheet for use in hot pressing, including a galvanized layer and a base steel sheet, wherein internal oxide is present on a side of the base steel sheet from an interface between the galvanized layer and the base steel sheet, the base steel sheet including defined C, Si, Mn, and Cr, with the balance being iron and inevitable impurities, wherein the base steel sheet satisfies the following formula (1):


(2?[Si]/28.1+[Mn]/54.9+1.5?[Cr]/52.0)?0.05(1)

wherein, in the formula (1), [Si] represents a Si content in mass % of the base steel sheet, [Mn] represents a Mn content in mass % of the base steel sheet, and [Cr] represents a Cr content in mass % of the base steel sheet.

Method for manufacturing high manganese hot-dip galvanized steel sheet with excellent coatability and ultra-high strength, and high manganese hot-dip galvanized steel sheet manufactured by said method
10087511 · 2018-10-02 · ·

There are provided a method for manufacturing a high manganese hot-dip galvanized steel sheet having superior coatability and ultra-high strength, and a high manganese hot-dip galvanized steel sheet manufactured by the method. The method includes: cold rolling a hot-rolled steel sheet to form a cold-rolled steel sheet, the hot-rolled steel sheet including, by wt %, C: 0.3% to 1%, Mn: 8% to 25%, Si: 0.1% to 3%, Al: 0.01% to 8%, Cr: 0.1% to 2%, Ti: 0.01% to 0.2%, B: 0.0005% to 0.01%, Ni: 0.01% to 2%, Sn: 0.06% to 0.2%, and a balance of Fe and inevitable impurities; heating the cold-rolled steel sheet; cooling the heated steel sheet to, or maintaining the heated steel sheet; and performing a hot-dip galvanizing process on the cooled or temperature-maintained steel sheet by dipping the cooled or temperature-maintained steel sheet into a hot-dip galvanizing bath.

METHOD OF PRODUCING HOT-DIP GALVANIZED STEEL SHEET

A method includes: annealing a steel strip by conveying the steel strip through a heating zone, a soaking zone, and a cooling zone in this order inside an annealing furnace; and applying a hot-dip galvanized coating onto the steel strip discharged from the cooling zone. Reducing gas or non-oxidizing gas supplied into the soaking zone includes humidified gas and dry gas. While a width and a sheet passing speed of the steel strip passing through the soaking zone are constant, a variation of pressure in the annealing furnace is suppressed by adjusting a flow rate of the dry gas, and a variation range of an amount of moisture supplied into the soaking zone by the humidified gas is limited to 20% or less.

Production method for plated steel sheet using a steel sheet annealing device
10053749 · 2018-08-21 · ·

Provided is a method for producing plated steel sheet by means of an annealing device which includes at least one section and in which the at least one section is filled with a gas constituting a non-reducing atmosphere or a weakly reducing atmosphere to substantially improve the quality of plating onto hot-dipped steel sheet, including the plating properties, alloying properties, anti-pickup properties, plating adhesion properties, anti-flaking properties, anti-cratering properties and anti-ash properties, by using prior-art annealing equipment and heat-treatment cycle without any additional oxidation-reduction heat treatment process or large quantities of high-cost alloying elements.

Metal sheet with a ZnAl coating

The present invention provides a method for manufacturing a metal sheet. In this method, at least one of the following equations is satisfied: Z d + 18 ln ( Z d ) < 8 ln ( P V ) - 27.52 ( A ) fO 2 < 2.304 .Math. 10 - 3 ( 27.52 + Z d + 8 ln ( V P

Method for the fabrication of a resistance spot weld

A method for the fabrication of a resistance spot weld containing not more than two Liquid Metal Embrittlement cracks having a depth of 100 ?m or more, the method includes the following successive steps of providing at least two first zinc or zinc-alloy coated sheets having a first steel substrate of a first steel, with TS>900 MPa, a thickness of the zinc or zinc-alloy coated sheets being between 0.5 and 2.5 mm; measuring C1.sub.av(100), Si1.sub.av(100), Mn1.sub.av(100), Al1.sub.av(100), Cr1.sub.av(100), designating respectively the average content of C, Si, Mn, Al, Cr in the zone D.sub.100 of the first steel substrate comprised between 0 and 100 micrometers under the zinc or zinc-alloy coating; then calculating a factor CSI.sub.1 of the first steel CSI.sub.1=C1.sub.av(100)+(Si1.sub.av(100)/32)+(Mn1.sub.av(100)/14)?(Al1.sub.av(100)/48)+(Cr1.sub.av(100)/11) then; performing resistance spot welding on at least 10 welds with a certain intensity. A second steel sheet can be provided depending on measurements.

Non-magnetic stainless steel wire as an armouring wire for power cables

A non-magnetic stainless steel wire with an adherent corrosion resistant coating is disclosed. The surface of the non-magnetic stainless steel is pre-treated so as to be sufficiently free from oxides and form a good adhesion with the above corrosion resistant coating. The non-magnetic stainless steel wire is used as a armoring wire for a power cable for transmitting electrical power.

HIGH-STRENGTH HOT-DIP GALVANIZED STEEL SHEET HAVING EXCELLENT PLATING SURFACE QUALITY AND ADHESION, AND METHOD OF MANUFACTURING THE SAME
20180119263 · 2018-05-03 ·

Provided is a method of manufacturing a hot-dip galvanized steel sheet. According to an aspect of the present invention, the method may include preparing a base steel sheet, forming a iron (Fe)-plated layer on the prepared base steel sheet, oxidation heating the steel sheet having the Fe-plated layer formed thereon at a temperature ranging from 600 C. to 800 C., maintaining the heated steel sheet at a temperature ranging from 750 C. to 900 C. for 5 seconds or more in a reducing atmosphere with a dew point of between -30 C. to 5 C. including 20 ppm or less of oxygen, 1 vol % to 20 vol % of H.sub.2, and N.sub.2 as well as unavoidable gases as a remainder, cooling the maintained steel sheet, and plating the cooled steel sheet by dipping in a hot-dip galvanizing bath.

Precoated sheets for manufacturing press-hardened coated steel parts

A cold-rolled sheet is provided. The cold-rolled sheet includes a steel substrate with a carbon content C.sub.0 between 0.07% and 0.5%, expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate. The substrate has a decarburized area on the surface of each of the two principal faces. The depth p.sub.50% of the decarburized area is between 6 and 30 micrometers, and p.sub.50% is the depth at which the carbon content is equal to 50% of the content C.sub.0. The sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating.

METHOD AND DEVICE FOR REACTION CONTROL
20180100209 · 2018-04-12 ·

A method for controlling surface reactions on a steel strip running through a furnace includes, successively, a first section, a second section, and a third section separated by a sealing element, an atmosphere in the second and third sections being oxidizing and reducing respectively, the method including: heating, in the first section, the steel strip to between 600 and 750 C., while causing the atmosphere therein to be slightly oxidizing and to include: an H.sub.2 content inferior to 2%; an O.sub.2 content inferior to 0.1%; an H.sub.2O or CO.sub.2, or H.sub.2O+CO.sub.2 content superior to 0.03%; a controlled dew point ranging from 50 to 15 C.; and a controlled concentration of CO+CO.sub.2 maintained below 2%. All percentages are expressed in terms of volume.