A method for reducing surface roughness of an article includes contacting a surface of an article with a molten metal agent, the surface having an initial roughness; altering at least a portion of the surface in the molten metal agent; and removing the surface from contact with the agent; wherein, after the removing step, the surface has a processed roughness that is less than the initial roughness.

A method for reducing surface roughness of an article includes contacting a surface of an article with a molten metal agent, the surface having an initial roughness; altering at least a portion of the surface in the molten metal agent; and removing the surface from contact with the agent; wherein, after the removing step, the surface has a processed roughness that is less than the initial roughness.

A hot-dip galvanized steel sheet wherein the hot-dip galvanized steel sheet comprises a base steel sheet and a hot-dip galvanized layer, a ferrite phase is, by volume fraction, 50% or less in a range of ⅛ thickness to ⅜ thickness centered at a position of ¼ thickness from the surface of the base steel sheet, a hard structure is 50% or more, wherein the hot-dip galvanized steel sheet has the hot-dip galvanized layer in which Fe is 5.0% or less and Al is 1.0% or less, and columnar grains formed of a ζ phase is 20% or more in an entire interface between the plated layer and the base steel sheet, on the surface of the base steel sheet in which a volume fraction of a residual austenite is 3% or less and a ratio of a volume fraction of the hard structure is 0.10 times or more to 0.90 times or less of that of the hard structure in the range of ⅛ thickness to ⅜ thickness in a range of 20 μm depth in a steel sheet direction originating an interface between the hot-dip galvanized layer and the base steel sheet, and wherein the hot-dip galvanized steel sheet has a refined layer at the side of the interface in the base steel sheet, and wherein an average thickness of the refined layer, an average grain size of ferrite in the refined layer and a maximum size of the oxide included in the refined layer are defined respectively.

Methods of strengthening surface regions of high-strength transformation induced plasticity (TRIP) steel are provided. The method may comprise shot peening at least one region of an exposed surface of a hot-formed press-hardened component comprising a high-strength steel. Prior to shot peening, the component has a microstructure comprising ≧about 5% by volume retained austenite in a matrix of martensite. The shot peening is conducted at a temperature of <about 150° C. and forms at least one hardened surface region comprising ≦about 2% by volume austenite. The TRIP steel may be zinc-coated and having a surface coating comprising zinc and substantially free of liquid metal embrittlement (LME). Zinc-coated hot-formed press-hardened components, including automotive components, formed from such methods are also provided.

Methods of strengthening surface regions of high-strength transformation induced plasticity (TRIP) steel are provided. The method may comprise shot peening at least one region of an exposed surface of a hot-formed press-hardened component comprising a high-strength steel. Prior to shot peening, the component has a microstructure comprising ≧about 5% by volume retained austenite in a matrix of martensite. The shot peening is conducted at a temperature of <about 150° C. and forms at least one hardened surface region comprising ≦about 2% by volume austenite. The TRIP steel may be zinc-coated and having a surface coating comprising zinc and substantially free of liquid metal embrittlement (LME). Zinc-coated hot-formed press-hardened components, including automotive components, formed from such methods are also provided.

A support tooling for porous preforms intended to be infiltrated by a molten metal includes a rack including two suspension bars each extending longitudinally along a first direction, the suspension bars being held spaced apart from one another along a second direction perpendicular to the first direction; a plurality or porous preform supports removably mounted on the suspension bars, each support including a first portion connected to one of the suspension bars by a connection sliding along a third direction perpendicular to the first and second directions and a second portion extending from the first portion and including support elements which are able to hold a porous preform by point or linear contact.

A support tooling for porous preforms intended to be infiltrated by a molten metal includes a rack including two suspension bars each extending longitudinally along a first direction, the suspension bars being held spaced apart from one another along a second direction perpendicular to the first direction; a plurality or porous preform supports removably mounted on the suspension bars, each support including a first portion connected to one of the suspension bars by a connection sliding along a third direction perpendicular to the first and second directions and a second portion extending from the first portion and including support elements which are able to hold a porous preform by point or linear contact.

A method for producing a hot-dip galvanized steel sheet includes supplying humidified gas to the soaking zone 12 in a manner such that: in passes in which the steel sheet moves upward, the humidified gas is supplied from first humidified gas supply ports 40A to 40E provided at positions higher by 1.0 m or more and 5.0 m or less than the centers of lower hearth rolls 54 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone; and in passes in which the steel sheet moves downward, the humidified gas is supplied from second humidified gas supply ports 42A to 42E provided at positions lower by 1.0 m or more and 5.0 m or less than the centers of the upper hearth rolls 52 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone.

Provided is a continuous hot-dip galvanizing apparatus comprising: a vertical annealing furnace having heating, soaking zone, and cooling zones therein; and a hot-dip galvanizing line downstream of the cooling zone. The heating, soaking, and cooling zones each have, in its upper portion, at least one upper hearth roll and, in its lower portion, at least one lower hearth roll. The soaking zone has a first and second humidified gas supply ports to supply a humidified gas having a dew point of 10° C. to 30° C. to the soaking zone. The first and second humidified gas supply ports are 1.0 m to 5.0 m lower than the center of the lower and upper hearth rolls, respectively, and overlap the steel sheet. The first humidified gas supply port is provided only for an ascending pass and the second humidified gas supply port is provided only for a descending pass.

The present disclosure provides methods of preparing heterostructures of a carbon-based structure and a metal oxide structure. Also provided are heterostructures formed via the methods described herein and devices comprising such heterostructures.