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 method of extending the corrosion resistance of a ground anchoring region of a steel or alloy fence or trellis post already having a sacrificial coating or non-sacrificial coating along an entire length of the fence or trellis post, said method including the step of applying at least one additional coating to the ground anchoring region so as to extend the corrosion resistance of the ground anchoring region. The at least one additional coating can be a sacrificial coating and/or non-sacrificial coating.

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.

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.

Provided are a zinc-base plated steel material comprising a base steel and a zinc-based plated layer and a post-treatment film, which are sequentially formed on the base steel. The post-treatment film comprises an oxide or oxide salt of at least one group A element selected from B, Al, V, and Fe and an organic compound, wherein the content of oxygen atoms in the post-treatment film is 50 atom % or more, and wherein when the mole number of oxygen atoms forming a covalent bond with hydrogen in the post-treatment film is a and the mole number of oxygen atoms not forming the covalent bond with hydrogen is b, a/b is 0.3 or greater; and a composition for forming the post-treatment film.

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.

A hot-dip galvanized steel sheet including: a hot-dip galvanizing layer on at least one side of a base steel sheet. The hot-dip galvanizing layer has a Fe content of more than 0% to 3.0% and an Al content of more than 0% to 1.0%. The hot-dip galvanized steel sheet includes a Fe—Al alloy layer provided on an interface between the hot-dip galvanizing layer and the base steel sheet and a fine-grain layer provided in the base steel sheet and directly in contact with the Fe—Al alloy layer. The Fe—Al alloy layer has a thickness of 0.1-2.0 μm. The fine-grain layer has an average thickness of 0.1-5.0 μm, includes a ferrite phase with an average grain diameter of 0.1-3.0 μm, and contains oxides of one or more out of Si and Mn, a maximum diameter of the oxides being 0.01-0.4 μm.

The present invention provides steel sheet products having controlled compositions that are subjected to two-step annealing processes to produce sheet products having desirable microstructures and favorable mechanical properties such as high strength and ultra-high formability. Steels processed in accordance with the present invention exhibit combined ultimate tensile strength and total elongation (UTS.Math.TE) properties of greater than 25,000 MPa-%. Steels with these properties fall into the category of Generation 3 advanced high strength steels, and are highly desired by various industries including automobile manufacturers.

The present invention relates to an alloy-coated steel sheet comprising: a steel sheet, and Al—Mg—Si—Zn alloy layer positioned on the steel sheet, wherein the Al—Mg—Si—Zn alloy layer comprises a Mg—Zn alloy phase, and wherein the Mg—Zn alloy phase comprises MgZn.sub.2 and Mg.sub.2Zn.sub.11, and the Mg—Zn alloy phase further comprises at least one of MgZn, Mg.sub.21Zn.sub.25, Mg.sub.51Zn.sub.20 and Mg.sub.2Zn.sub.3.

An exhaust component for a motor vehicle with improved corrosion resistance, including a housing with outer walls that define an internal volume and one or more inner walls that divide the internal volume into an exhaust chamber and an interior chamber. The interior chamber is isolated from the exhaust chamber and the external environment. At least part of one outer wall or one inner wall is made of a diffusion surface alloyed metal sheet. The diffusion surface alloyed metal sheet comprises a secondary metal that is formed to a primary metal substrate by diffusion. The diffusion surface alloyed metal sheet includes edges that are oriented toward and exposed to the interior chamber. As a result, the primary metal substrate at the edges of the diffusion surface alloyed metal sheet is protected from exposure to corrosives such as salt spray in the external environment and urea in the exhaust chamber respectively.