Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing as high as TS: 1780 MPa or more, excellent resistance to resistance welding cracking, and excellent delayed fracture resistance after resistance welding by having a specific chemical composition, and a microstructure such that a prior austenite average grain size is 7 μm or less, a volume fraction of martensite is 90% or more, and at least 5 Nb-based precipitates having a grain size of less than 0.08 μm are present on average per 100 μm.sup.2 of a cross section parallel to a thickness direction of the member within a range of 100 μm in the thickness direction from a surface of the member, and such that a Ni diffusion region having a thickness of 0.5 μm or more is present in a surface layer of the member.

The present invention concerns a turbine part comprising a substrate made of nickel-based monocrystalline superalloy, comprising chromium and at least one element chosen among rhenium and ruthenium, the substrate having a γ-γ′ phase, an average mass fraction of rhenium and of ruthenium greater than or equal to 4% and an average mass fraction of chromium less than or equal to 5% and preferably less than or equal to 3%, a sub-layer covering at least a part of a surface of the substrate, characterised in that the sublayer has a γ-γ′ phase and an average atomic fraction of chromium greater than 5%, of aluminium between 10% and 20% and of platinum between 15% and 25%.

A welding method for a connector and a connection tube of a heat exchanger are proposed. The method includes: forming a diffusion layer on a surface of the connector, a corrosion potential of the diffusion layer being less than a corrosion potential of the connector; inserting a connection tube into the connector; brazing the connection tube to the connector by a brazing filler metal, a corrosion potential of a weld metal formed after brazing of the brazing filler metal being higher than the corrosion potential of the connector and less than a corrosion potential of the connection tube.

An article and a method of manufacturing the article is disclosed. The method includes providing the article including a substrate and a coating at least partially disposed on the substrate. The coating includes an outer surface. The coating further includes platinum and chromium. The method further includes applying cold work to the outer surface of the coating to produce a cold-worked layer extending from the outer surface of the coating to a cold work depth. The cold-worked layer includes approximately 45% cold work. The cold work depth is between about 30 microns to about 150 microns from the outer surface of the coating.

A process for coating a part by chemical vapor diffusion is provided and includes placing a powder mixture in a chamber, immersing the part partially in the powder mixture, and applying a heat treatment to the part. The powder mixture includes a first component and a second component forming a gaseous compound during the heat treatment so as to allow deposition of the second component on the part. The part includes a metal refractory allow and the second component forms a solid diffusion alloy by solid diffusion with a metal species of the refractory metal alloy to generate a coating. The solid diffusion allow generates a passivating oxide layer when subjected to oxidizing conditions.

Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing as high as TS: 1780 MPa or more, and excellent resistance to resistance welding cracking by properly adjusting its chemical composition and its microstructure such that a prior austenite average grain size is 7.5 μm or less, a volume fraction of martensite is 95% or more, and at least 10 Nb-based and Ti-based precipitates having a grain size of less than 0.10 μm are present on average per 100 μm.sup.2 of a cross section parallel to a thickness direction of the member within a range of 100 μm or less in the thickness direction from the surface of the member, and such that a B concentration in prior austenite grain boundaries is at least 3.0 times a B concentration at a position 5 nm away from the grain boundaries.

The invention relates to a process for manufacturing a part made of nickel-based monocrystalline superalloy containing hafnium. This process is noteworthy in that it comprises the following successive steps consisting in: —manufacturing a nickel-based monocrystalline superalloy that is not doped with hafnium, —manufacturing a part from this superalloy, —directly depositing on said part a layer of hafnium having a thickness of between 50 nm and 800 nm, —carrying out a diffusion treatment of the hafnium so as to form an interdiffusion layer at the surface of said part and to thus obtain a part made of nickel-based monocrystalline superalloy containing hafnium.

The invention relates to a process for manufacturing a part made of nickel-based monocrystalline superalloy containing hafnium. This process is noteworthy in that it comprises the following successive steps consisting in: —manufacturing a nickel-based monocrystalline superalloy that is not doped with hafnium, —manufacturing a part from this superalloy, —directly depositing on said part a layer of hafnium having a thickness of between 50 nm and 800 nm, —carrying out a diffusion treatment of the hafnium so as to form an interdiffusion layer at the surface of said part and to thus obtain a part made of nickel-based monocrystalline superalloy containing hafnium.

Provided are a high-strength cold-rolled steel sheet and a hot-dip galvanized steel sheet comprising in % by weight: 0.05 to 0.3% of carbon (C); 0.6 to 2.5% of silicon (Si); 0.01 to 0.5% of aluminum (Al); 1.5 to 3.0% of manganese (Mn); and the remainder being Fe and unavoidable impurities, the steel sheet has a microstructure comprised of, in an area fraction, ferrite in an amount of 60% or less, lath-type bainite of 25% or more, martensite of 5% or more, and lath-type retained austenite in an amount of 5%, wherein the ferrite has an average grain diameter of 2 μm or less and the ferrite satisfies Fn2, defined by relational expression 1, is 89% or more and Fa5, defined by relational expression 2, is 70% or less.

An electrode wire for use in an electrical discharge machining apparatus includes a metallic core and a layer of gamma phase brass disposed over the metallic core. Particles of beta phase brass are interspersed within the gamma phase brass layer. An oxide layer including zinc is disposed over the gamma phase brass layer.