Abstract: The present invention provides plated steel sheet for hot press use which is excellent in hot lubricity, coating adhesion, spot weldability, and coated corrosion resistance and a method of hot pressing plated steel sheet. The present invention is Plated steel sheet for hot press use and a method of hot pressing plated steel sheet characterized by being plated steel sheet for hot press use which contains an Al plating layer which is formed on one surface or both surfaces of said steel sheet, and a surface coating layer which is formed on said Al plating layer, said surface coating layer containing at least one Zn compound which is selected from a group comprised of Zn hydroxide, Zn phosphate, and a Zn organic acid.

Abstract: An Al-plated steel sheet includes: a steel sheet; an Al plating layer which is formed on one surface or both surfaces of the steel sheet and contains at least 85% or more of Al by mass %; and a surface coating layer which is laminated on the surface of the Al plating layer and contains ZnO and one or more lubricity improving compounds.

Abstract: A hot stamped high strength part in which the propagation of cracks which form at the plating layer at the time of hot stamping when hot stamping aluminum plated steel sheet is suppressed and the post painting anticorrosion property is excellent even without adding special ingredient elements which suppress formation of cracks in an aluminum plating layer is provided.

Abstract: A high strength hot dipped galvanized steel sheet is provided. By controlling the amount of addition of Ti instead of the addition of Nb or B, it is possible to obtain an effect of retarding recrystallization and grain growth even if annealing by a continuous annealing process in a temperature range of the general annealing temperature of 720° C. to a temperature of the lower of 800° C. or Ac3 temperature. By controlling the rolling and heat treatment conditions, it is possible to control the ferrite phase rate, grain size of the low temperature transformed phases, ratio of average values of the nano hardnesses of the ferrite phase and low temperature transformed phases, and fluctuations of hardnesses of the low temperature transformed phases in a composite structure steel of ferrite and low temperature transformed phases and obtain a high strength hot dipped galvanized steel sheet.

Abstract: A high strength hot dipped galvanized steel sheet is provided. By controlling the amount of addition of Ti instead of the addition of Nb or B, it is possible to obtain an effect of retarding recrystallization and grain growth even if annealing by a continuous annealing process in a temperature range of the general annealing temperature of 720° C. to a temperature of the lower of 800° C. or Ac3 temperature. By controlling the rolling and heat treatment conditions, it is possible to control the ferrite phase rate, grain size of the low temperature transformed phases, ratio of average values of the nano hardnesses of the ferrite phase and low temperature transformed phases, and fluctuations of hardnesses of the low temperature transformed phases in a composite structure steel of ferrite and low temperature transformed phases and obtain a high strength hot dipped galvanized steel sheet.

Abstract: A hot stamped high strength part in which the propagation of cracks which form at the plating layer at the time of hot stamping when hot stamping aluminum plated steel sheet is suppressed and the post painting anticorrosion property is excellent even without adding special ingredient elements which suppress formation of cracks in an aluminum plating layer is provided.

Abstract: The present invention solves the problem of melting of Al in heating before hot-stamping, which had been a problem in the past in applying hot-stamping to Al-plated steel sheet, and provides Al-plated steel sheet for hot-stamping and a method of hot-stamping using that Al-plated steel sheet to solve the problem of delayed fracture due to residual hydrogen, and, furthermore, a method of a rapid heating hot-stamping using that Al-plated steel sheet. The Al-plated steel sheet of the present invention is produced by annealing the Al-plated steel sheet as coiled in a box-anneal furnace for the time and at the temperature indicated in FIG. 5, and alloying of a plated Al and a steel sheet. Further, a method of rapid heating hot-stamping in the present invention is characterized by cutting out a stamping blank of an Al-plated steel sheet, and heating that blank in heating before hot-stamping by an average temperature with a rising rate of 40° C./sec or more and a time of exposure to an environment of 700° C.

Abstract: A hot stamped high strength part which is excellent in post painting anticorrosion property, which hot stamped high strength part has an alloy plating layer including an Al—Fe intermetallic compound phase on the surface of the steel sheet. The alloy plating layer is comprised from phases of a plurality of intermetallic compounds, a mean linear intercept length of crystal grains of a phase containing Al: 40 to 65 mass % among the phases of the plurality of intermetallic compounds is 3 to 20 ?m, an average value of thickness of the Al—Fe alloy plating layer is 10 to 50 ?m, and a ratio of the average value of thickness to the standard deviation of thickness of the Al—Fe alloy plating layer satisfies the following relationship: 0<standard deviation of thickness/average value of thickness?0.15.

Abstract: An Al-plated steel sheet includes: a steel sheet; an Al plating layer which is formed on one surface or both surfaces of the steel sheet and contains at least 85% or more of Al by mass %; and a surface coating layer which is laminated on the surface of the Al plating layer and contains ZnO and one or more lubricity improving compounds.

Abstract: The present invention provides plated steel sheet for hot press use which is excellent in hot lubricity, coating adhesion, spot weldability, and coated corrosion resistance and a method of hot pressing plated steel sheet. The present invention is Plated steel sheet for hot press use and a method of hot pressing plated steel sheet characterized by being plated steel sheet for hot press use which contains an Al plating layer which is formed on one surface or both surfaces of said steel sheet, and a surface coating layer which is formed on said Al plating layer, said surface coating layer containing at least one Zn compound which is selected from a group comprised of Zn hydroxide, Zn phosphate, and a Zn organic acid.

Abstract: A hot stamped high strength part in which the propagation of cracks which form at the plating layer at the time of hot stamping when hot stamping aluminum plated steel sheet is suppressed and the post painting anticorrosion property is excellent even without adding special ingredient elements which suppress formation of cracks in an aluminum plating layer is provided.

Abstract: The present invention has as its object the provision of steel sheet for hot stamping use which is excellent in part strength after hot stamping and delayed fracture resistance comprised of large C content high strength steel sheet in which effective hydrogen traps are formed in the steel material. The steel sheet of the present invention solves this problem by forming Fe—Mn-based composite oxides in the steel sheet and trapping hydrogen at the interfaces of the composite oxides and matrix steel and in the voids around the composite oxides. Specifically, it provides steel sheet for hot stamping use which is comprised of chemical ingredients which contain, by mass %, C: 0.05 to 0.40%, Si: 0.02% or less, Mn: 0.1 to 3%, S: 0.02% or less, P: 0.03% or less, Al: 0.005% or less, Ti: 0.01% or less, N: 0.01% or less, one or both of Cr and Mo in a total of 0.005 to 1%, and O: 0.003 to 0.03% and which have a balance of Fe and unavoidable impurities and which contains average diameter 0.

Abstract: High strength hot dipped galvanized steel sheet with little fluctuation in material quality at the time of production and excellent in shapeability is provided. By controlling the amount of addition of Ti instead of the addition of Nb or B, it is possible to obtain an effect of retarding recrystallization and grain growth even if annealing by a continuous annealing process in a temperature range of the general annealing temperature of 720° C. to a temperature of the lower of 800° C. or Ac3 temperature (easy annealing temperature region).

Abstract: The present invention solves the problem of melting of Al in heating before hot-stamping, which had been a problem in the past in applying hot-stamping to Al-plated steel sheet, and provides Al-plated steel sheet for hot-stamping and a method of hot-stamping using that Al-plated steel sheet to solve the problem of delayed fracture due to residual hydrogen, and, furthermore, a method of a rapid heating hot-stamping using that Al-plated steel sheet. The Al-plated steel sheet of the present invention is produced by annealing the Al-plated steel sheet as coiled in a box-anneal furnace for the time and at the temperature indicated in FIG. 5, and alloying of a plated Al and a steel sheet. Further, a method of rapid heating hot-stamping in the present invention is characterized by cutting out a stamping blank of an Al-plated steel sheet, and heating that blank in heating before hot-stamping by an average temperature with a rising rate of 40° C./sec or more and a time of exposure to an environment of 700° C.

Abstract: A method is proved for hot pressing hot rolled steel sheet, cold rolled steel sheet, Al-based plated steel sheet or Zn-based plated steel sheet, where the hot pressed sheet can exhibit a strength of at least about 1200 Mpa, and my be prevented from exhibiting hydrogen embrittlement. The steel sheet may include between about 0.05 to 0.5 wt % C, and/or it may be plated with an Al-based or Zn-based plating material. The steel sheet may be heating to a temperature greater than an Ac3 temperature and not more than about 1100° C. before pressing. An atmosphere can be provided during heating which contains not more than about 6 vol % of hydrogen and a dew point of not more than about 10° C. The exemplary methods may be used to form high strength parts which may be used, e.g., in automobiles.

Abstract: High-strength parts and a method for producing them can be provided, where such parts exhibit hydrogen embrittlement resistance and strength after high-temperature forming. For example, the atmosphere in a heating furnace can contain less than about 10% hydrogen and/or have a dew point of about 30° C. or less. The amount of hydrogen penetrating a steel sheet during heating can thereby be reduced. After forming, quench hardening in a die assembly and post-working can be performed. Post-working can include shearing followed by re-shearing or compression forming; punching with a cutting blade having a continuously reduced base width; punching with a tool having a curved blade and a protrusion at the tip of the cutting blade, where the curved blade may include a shoulder portion of given radius and/or angle; fusion cutting; etc. Tensile residual stresses after punching can be reduced and resistance to hydrogen embrittlement can be improved.

Abstract: The present invention provides a method of hot pressing using hot rolled and cold rolled steel sheet or Al-based plated steel sheet or Zn-based plated steel sheet enabling a strength of at least 1200 MPa to be obtained after high temperature forming and with extremely little possibility of hydrogen embrittlement and such hot pressed parts, that is, a method of hot pressing a high strength automobile parts comprising using steel sheet containing as steel compositions by wt % C:0.05 to 0.5% or steel sheet plated mainly with Al or Zn to produce automobile members by hot pressing during which making the heating temperature before pressing Ac3 or more to 1100° C. or less, making the hydrogen concentration in the heating atmosphere 6 vol % or less, and making the dew point 10° C. or less and such hot pressed parts.

Abstract: Disclosed is the provision of a non-aging, highly anti-seed and anti-black-speck steel plate for enameling without relying upon decarbonization-denitrification annealing involving increased production cost, and without the addition of expensive elements, such as niobium and titanium involving increased alloying cost. This steel plate is produced by adopting a steel composition comprising, by weight, carbon: not more than 0.0018%, silicon: not more than 0.020%, manganese: 0.10 to 0.30%, phosphorus: 0.010 to 0.030%, sulfur: not more than 0.030%, aluminum: not more than 0.005%, nitrogen: 0.0008 to 0.0050%, boron: not more than 0.0050% and not less than 0.6 time the nitrogen content, and oxygen: 0.010 to 0.05%, and regulating the chemical composition of the steel and regulating mainly hot rolling conditions to regulate the form of nitrides.

Abstract: Disclosed is the provision of a non-aging, highly anti-seed and anti-black-speck steel plate for enameling without relying upon decarbonization-denitrification annealing involving increased production cost, and without the addition of expensive elements, such as niobium and titanium involving increased alloying cost. This steel plate is produced by adopting a steel composition comprising, by weight, carbon: not more than 0.0018%, silicon: not more than 0.020%, manganese: 0.10 to 0.30%, phosphorus: 0.010 to 0.030%, sulfur: not more than 0.030%, aluminum: not more than 0.005%, nitrogen: 0.0008 to 0.0050%, boron: not more than 0.0050% and not less than 0.6 time the nitrogen content, and oxygen: 0.010 to 0.05%, and regulating the chemical composition of the steel and regulating mainly hot rolling conditions to regulate the form of nitrides.