A hot stamped body comprising a steel base material and an Al—Zn—Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 85.0% of an Mg—Zn containing phase and 15.0 to 90.0% of an Fe—Al containing phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, Mg.sub.2 Zn.sub.3 phase, and MgZn.sub.2 phase, and the Fe—Al containing phase comprises at least one of an FeAl phase and Fe—Al—Zn phase and an area ratio of the Fe—Al—Zn phase in the main layer is 10.0% or less.

A dust core including a metal magnetic powder and a resin, in which the metal magnetic powder shows a particle diameter of more than 0 μm and 200 μm or less, a number percentage of 5.0% or more of metal magnetic particles among the metal magnetic particles composing the metal magnetic powder are at least partially surface-coated with an inorganic compound including an alkaline earth metal, in a coating part coating the metal magnetic particles, an amount of the alkaline earth metal is 10.0 mass % or more, when a total amount of a metal element included in the coating part is 100 mass %, is provide. The dust core is superior in a corrosion-resistance.

A dust core including a metal magnetic powder and a resin, in which the metal magnetic powder shows a particle diameter of more than 0 μm and 200 μm or less, a number percentage of 5.0% or more of metal magnetic particles among the metal magnetic particles composing the metal magnetic powder are at least partially surface-coated with an inorganic compound including an alkaline earth metal, in a coating part coating the metal magnetic particles, an amount of the alkaline earth metal is 10.0 mass % or more, when a total amount of a metal element included in the coating part is 100 mass %, is provide. The dust core is superior in a corrosion-resistance.

Provided is a method for manufacturing a high-strength galvanized steel sheet. Heating in a first half of oxidizing treatment is performed at a temperature of 400° C. to 750° C. in an atmosphere having a particular O.sub.2 concentration and a particular H.sub.2O concentration, and heating in a second half of the oxidizing treatment is performed at a temperature of 600° C. to 850° C. in an atmosphere having a particular O.sub.2 concentration and a particular H.sub.2O concentration. Subsequently, heating in a heating zone for reduction annealing is performed to a temperature of 650° C. to 900° C. at a particular heating rate in an atmosphere having a particular H.sub.2 concentration and a particular H.sub.2O concentration with the balance being N.sub.2 and inevitable impurities, and soaking in a soaking zone for the reduction annealing is performed in an atmosphere having a particular H.sub.2 concentration and a particular H.sub.2O concentration with the balance being N.sub.2 and inevitable impurities.

Provided is a method for manufacturing a high-strength galvanized steel sheet. Heating in a first half of oxidizing treatment is performed at a temperature of 400° C. to 750° C. in an atmosphere having a particular O.sub.2 concentration and a particular H.sub.2O concentration, and heating in a second half of the oxidizing treatment is performed at a temperature of 600° C. to 850° C. in an atmosphere having a particular O.sub.2 concentration and a particular H.sub.2O concentration. Subsequently, heating in a heating zone for reduction annealing is performed to a temperature of 650° C. to 900° C. at a particular heating rate in an atmosphere having a particular H.sub.2 concentration and a particular H.sub.2O concentration with the balance being N.sub.2 and inevitable impurities, and soaking in a soaking zone for the reduction annealing is performed in an atmosphere having a particular H.sub.2 concentration and a particular H.sub.2O concentration with the balance being N.sub.2 and inevitable impurities.

A MIG welding method for carbon steels using an Ar shielding gas. The method includes short-circuiting a welding wire and a base material. The average short-circuiting frequency in welding is 20 Hz to 300 Hz and the maximum short-circuiting period is 1.5 s or less.

A Ni-plated steel sheet includes a base steel sheet and a Ni-based coating layer that is disposed on a surface of the base steel sheet. The distribution of carbon concentration in a depth direction obtained by performing GDS analysis on the Ni-plated steel sheet has a peak indicating the carbon concentration that is equal to or more than twice the carbon concentration of a thickness middle portion of the base steel sheet in the vicinity of an interface between the base steel sheet and the Ni-based coating layer.

A Ni-plated steel sheet includes a base steel sheet and a Ni-based coating layer that is disposed on a surface of the base steel sheet. The distribution of carbon concentration in a depth direction obtained by performing GDS analysis on the Ni-plated steel sheet has a peak indicating the carbon concentration that is equal to or more than twice the carbon concentration of a thickness middle portion of the base steel sheet in the vicinity of an interface between the base steel sheet and the Ni-based coating layer.

A normalizing heat-treated steel sheet having good low-temperature impact toughness and a method for manufacturing the same is provided. The normalizing heat treated steel sheet of the present invention contains, by weight %, C: 0.04 to 0.1%, Si: 0.05 to 0.5%, Mn: 1.0 to 2.0%, Sol. Al: 0.015 to 0.04%, Nb: 0.003 to 0.03%, Ti: 0.005 to 0.02%, Cu: 0.35% or less, Ni: 0.05 to 0.8%, N: 0.002 to 0.008%, P: 0.01% or less (excluding 0%), S: 0.003% or less, and a balance of Fe and unavoidable impurities and has a steel microstructure composed of 70 to 90 area % of polygonal ferrite having a grain size of 20 μm or less, and 10 to 30 area % of spheroidized pearlite.

A normalizing heat-treated steel sheet having good low-temperature impact toughness and a method for manufacturing the same is provided. The normalizing heat treated steel sheet of the present invention contains, by weight %, C: 0.04 to 0.1%, Si: 0.05 to 0.5%, Mn: 1.0 to 2.0%, Sol. Al: 0.015 to 0.04%, Nb: 0.003 to 0.03%, Ti: 0.005 to 0.02%, Cu: 0.35% or less, Ni: 0.05 to 0.8%, N: 0.002 to 0.008%, P: 0.01% or less (excluding 0%), S: 0.003% or less, and a balance of Fe and unavoidable impurities and has a steel microstructure composed of 70 to 90 area % of polygonal ferrite having a grain size of 20 μm or less, and 10 to 30 area % of spheroidized pearlite.