Provided is a soldering system based on nickel, manganese, chromium, aluminum and titanium, a fracture free alternative to the soldering of nickel or cobalt-based alloys is created. Disclosed is an alloy which comprises, as alloy elements, at least the following (in % by weight): manganese, in particular from 10%-16%, very particularly preferably from 12% to 15%, chromium, in particular from 3% to 10%, very particularly preferably from 5% to 8%, aluminum, in particular from 1% to 6%, very particularly preferably from 2% to 4%, titanium, in particular from 1% to 6%, very particularly preferably from 2% to 4%, nickel, in particular nickel as balance, very particularly preferably nickel-based.

A Ni-based alloy for a welding material including, by mass, 0.001 to 0.1% of C, 18 to 25% of Co, 16 to 20% of Cr, 2.5 to 3.5% of Al, 9.0 to 15.0% of Mo+W, 0.001 to 0.03% of B and the balance being Ni and inevitable impurities.

The invention discloses a nickel based brazing filler metal in form of an alloy containing or consisting of between 20 wt % and 35 wt % chromium, between 7 wt % and 15 wt % iron and between 2.5 wt % and 9 wt % silicon, between 0 wt % and 15 wt % molybdenum, unavoidable impurities and the balance being nickel. The solidus temperature of the brazing filler shall be between 1140 C. and 1240 C. The brazing filler metal is suitable for production of catalytic converters and heat exchangers.

The invention also discloses a brazing method.

A submerged arc welding process using welding wire containing, based on the total mass of the welding wire, Ni: 50% or more by mass, Cr: 14.5% to 16.5% by mass, Mo: 15.0% to 17.0% by mass, W: 3.0% to 4.5% by mass, Fe: 4.0% to 7.0% by mass, and C, Si, Mn, P, S, Cu, V, Co, and Al: a predetermined amount or less, and a bonded flux containing, based on the total mass of the bonded flux, Al.sub.2O.sub.3: 35% to 55% by mass, SiO.sub.2: 5% to 25% by mass, CaO: 2% to 10% by mass, CaF.sub.2: 25% to 45% by mass, and Na.sub.2O: 2% to 4% by mass.

Provided is a brazing alloy powder with which the development of defect in a brazed portion is suppressed and which enables an increase in the joint strength of the portion to be joined. Also provided is a brazed joined component having a high joint strength of the portion to be joined. The brazing alloy powder includes particles which include 55 mass % or more of at least one element selected from Ni, Fe, and Co. The alloy powder includes not less than 10% alloy particles having an amorphous phase. In addition, d9060 m, where d90 is the grain diameter indicating 90% in an integral volume distribution curve according to a laser diffraction scattering method. The joined component includes a plurality of members joined with a brazing material including the brazing alloy powder.

In one aspect, methods of making freestanding metal matrix composite articles and alloy articles are described. A method of making a freestanding composite article described herein comprises disposing over a surface of the temporary substrate a layered assembly comprising a layer of infiltration metal or alloy and a hard particle layer formed of a flexible sheet comprising organic binder and the hard particles. The layered assembly is heated to infiltrate the hard particle layer with metal or alloy providing a metal matrix composite, and the metal matrix composite is separated from the temporary substrate. Further, a method of making a freestanding alloy article described herein comprises disposing over the surface of a temporary substrate a flexible sheet comprising organic binder and powder alloy and heating the sheet to provide a sintered alloy article. The sintered alloy article is then separated from the temporary substrate.

Nickel base superalloys, including in some embodiments 5% to 7% Fe, which were previously developed and used for their corrosion resistance, also possess favorable characteristics for use as a braze filler in repair or joining of superalloy substrates, such as those used to form turbine engine blades and vanes, heat exchangers, vessels, and piping. In particular, such corrosion-resistant nickel base superalloys have favorable characteristics for wide-gap brazing of gaps greater than one millimeter in superalloy substrates that preserves favorable material properties throughout the braze region in the substrate.

In a stainless steel flux cored wire comprising a stainless steel shell and a flux filling the shell, the amount of Si contained in the entire wire is 2.5% by mass or higher, preferably 3.0% by mass or higher in terms of SiO.sub.2, and the amount of at least one compound selected from the group consisting of polytetrafluoroethylene, graphite fluoride and perfluoropolyether contained in the flux is 0.005 to 0.10% by mass of the total mass of the wire in terms of F, preferably 0.020% by mass or higher. By employing such a constitution, in welding of CrNi-based and Cr-based stainless steels and other materials, fume generation and hexavalent chromium leaching can be significantly reduced, and excellent welding workability can be provided.

A method for applying a protective layer to protect against an impact stress includes mixing a sealing alloy in a powder form with a binder and water to form a pasty compound, applying the pasty compound on a surface to be protected, drying the applied pasty compound, and heating the dried applied pasty compound to a temperature of at least 800 C.

The invention provides a process for brazing two or three parts. A braze with a composition consisting of Ni.sub.resCr.sub.aB.sub.bP.sub.cSi.sub.d with 20 atomic percent<a<22 atomic percent; 1.2 atomic percentb3.6 percent; 12.5 atomic percentc14.5 atomic percent; 0 atomic percentd<1.5 atomic percent; incidental impurities0.5 atomic percent; and residual Ni is inserted between two or more parts to be joined to form a joint, the parts to be joined having a higher melting temperature than the braze. The joint is heated to a temperature of between 1020 C. and 1070 C. and cooled to form a brazed joint between the parts.