A steel sheet has a chemical composition with a steel structure containing, by volume fraction, soft ferrite: 0-30%, retained austenite: 3-40%, fresh martensite: 0-30%, pearlite and cementite: 0-10%, and a remainder including hard ferrite. In the steel sheet, a number proportion of retained austenite having an aspect ratio of 2.0 or more in the total retained austenite is 50% or more, and a soft layer having a thickness of 1-100 μm is present. In the soft layer, a volume fraction of ferrite grains having an aspect ratio of less than 3.0 is 50% or more, and a volume fraction of retained austenite is 50% or more of the volume fraction of the retained austenite of the inside of the steel sheet. A peak of an emission intensity at a wavelength indicating Si appears in a range of more than 0.2 μm to 5 μm or less from the surface.

A high-strength galvanized steel sheet includes a steel sheet having a steel composition having a specific component composition, a steel structure containing martensite and bainite at more than or equal to 70% (including 100%), ferrite at less than 20% (including 0%), and retained austenite at less than 5% (including 0%) in terms of area ratio, the amount of diffusible hydrogen in steel being less than or equal to 0.20 mass ppm; and a galvanizing layer provided on a surface of the steel sheet, having a content amount of Fe of 8 to 15% in mass %, and having an coating weight per one surface of 20 to 120 g/m.sup.2, wherein the amount of Mn oxides contained in the galvanizing layer is less than or equal to 0.050 g/m.sup.2, and a tensile strength is more than or equal to 1100 MPa and a yield ratio is more than or equal to 0.85.

The present invention relates to a high-strength steel sheet which satisfies a specific chemical component composition, and which is configured such that: when the metal structure thereof is observed with a scanning electron microscope, polygonal ferrite is 30 to 60% by area; when the metal structure thereof is observed with an optical microscope, MA mixed structure is 21% by area or less; when the metal structure thereof is measured by an X-ray diffraction method, retained austenite is 8% by volume or more; an area ratio of polygonal ferrite having a circle equivalent diameter of 35.0 μm or more is 0% and an area ratio of polygonal ferrite having a circle equivalent diameter of 10.0 μm or more and less than 35.0 μm is 10% or less in the polygonal ferrite; and connectivity as defined by a specific relational expression is 10% or more.

In one aspect of the present invention, a hot-dip galvannealed steel sheet includes a steel sheet and a hot-dip galvannealed layer on the surface of the steel sheet. The steel sheet has a predetermined composition and has an average oxygen concentration of 0.10 mass % or less in the region of 1 μm from the interface between the steel sheet and the hot-dip galvannealed layer toward the steel sheet. The metal microstructure of the steel sheet at a position of t/4 where t represents the sheet thickness of the hot-dip galvannealed steel sheet includes 50 to 85 area % of martensite, 15 to 50 area % of bainite, and 5 area % or less of ferrite.

A friction material comprises an Fe part which contains Fe as a main component, a coating layer formed on a surface of the Fe part, and a friction part formed on a surface of at least a part of the coating layer, and the coating layer comprises a first coating layer and a second coating layer which have a specific average thickness and a specific component in order from Fe part side, and in the second coating layer, in order of positions at which the thickness is 20%, 40%, 60% and 80% of the second coating layer from the side of the first coating layer to the side opposite thereto, a Cu content increases and a Ni content decreases.

An amorphous metal ribbon includes a plurality of laser irradiation mark rows each including a plurality of laser irradiation marks arranged in a row, in which when a distance between the laser irradiation mark rows that are adjacent to each other is set as d1, a distance between the laser irradiation marks in the laser irradiation mark row is set as d2, a diameter of the laser irradiation mark is set as d3, and a number density D of the laser irradiation marks is set as (1/d1)×(1/d2), the number density D of the laser irradiation marks is 0.05 pieces/mm.sup.2 or more and 0.50 pieces/mm.sup.2 or less, and when an area occupancy rate A of the laser irradiation marks is set as D×(d3/2).sup.2×π×100, the area occupancy rate A of the laser irradiation marks is 0.0035% or more and 0.040% or less.

A metallic component includes a core formed of steel. A zinc alloy layer is disposed on the core. The zinc alloy layer is formed of zinc and a very small amount of aluminum, such as 0.14 weight percent or less. A method of creating a component includes providing a steel core, providing a zinc bath consisting of essentially of 0.01 to 0.14 weight percent aluminum, and hot dipping the steel core into the zinc bath to form a zinc coating on the steel core resulting in a zinc-coated steel component. The aluminum may be provided in even lower contents, such as less than 0.08 weight percent, or even less than 0.05 weight percent. The zinc-coated steel component may then be spot welded to another component without first annealing the zinc-coated component. Rather, heat treating is performed locally at the weld joint by the welding procedure alone.

A machine component includes a core made up of a steel for machine structural use, and a medium carbon-containing layer and a high carbon-containing layer formed of the steel for machine structural use, the medium carbon-containing layer covering the core, the high carbon-containing layer covering the medium carbon-containing layer and having a carbon concentration of 0.8-1.5%. The high carbon-containing layer is made up of a martensitic structure having carbides dispersed therein and a residual austenitic structure, wherein spheroidized carbides with an aspect ratio of 1.5 or less constitute 90% or more of a total number of the carbides, and the number of spheroidized carbides on prior austenite grain boundaries is 40% or less of the total number of the carbides.

A slide member is provided with a base material, a plated slide layer and an intermediate plated layer. The plated slide layer contains a solid lubricant. The intermediate plated layer is disposed between the base material and the plated slide layer, the intermediate plated layer increasing cohesion of the base material and the plated slide layer. The plated slide layer has a content of the solid lubricant in a range from 30 to 70 vol %, inclusive.

There is provided a hot-stamped body including: a steel base metal; and a metallic layer formed on a surface of the steel base metal, wherein the metallic layer includes: an interface layer that contains, in mass %, Al: 30.0 to 36.0%, has a thickness of 100 nm to 15 μm, and is located in an interface between the metallic layer and the steel base metal; and a principal layer that includes coexisting Zn phases and insular FeAl.sub.2 phases, is located on the interface layer, and has a thickness of 1 μm to 40 μm. This hot-stamped body is excellent in fatigue properties, corrosion resistance, and chipping resistance.