A NiCrFe-based alloy brazing filler material to which Cu is added, and which has a low melting temperature, and is inexpensive and excellent in corrosion resistance and in strength, for use in manufacture of stainless-steel heat exchangers or the like, specifically, a NiCrFe-based alloy brazing filler material, including, in mass %, Cr: 15 to 30%; Fe: 15 to 30%; Cu: 2.1 to 7.5%; P: 3 to 12%; and Si: 0 to 8%; and the balance being Ni and unavoidable impurities, wherein the total content of Cr and Fe is 30 to 54%, and the total content of P and Si is 7 to 14%.

The exposed metal tip of the strike end of an SMAW welding electrode is covered with a protective coating formed from a binder and metal particles. Because metal particles rather than graphite particles are used to provide electrical conductivity to this protective coating, flare-up of the arc when initially struck is eliminated substantially completely. In addition, the potential for weld porosity problems is also eliminated, because the metal particles of the inventive electrode do not produce CO.sub.2 as a reaction by-product which can ultimately lead to improper welding technique.

A method of making pre-sintered preforms using a mixture of base superalloy particles and titanium-containing boron and silicon free braze alloy particles, such as for the repair of superalloy gas turbine engine components. Alloy particles as large as 2 mm provide reduced shrinkage when compared to prior art preforms. Braze material compositions disclosed herein are boron and silicon free and may have melting temperature ranges as low as 10 C., and they include no element not already present in the composition of the superalloy component.

There is provided a welding structure member excellent in corrosion resistance in an environment where high-concentration sulfuric acid condenses, the welding structure member including base material having a chemical composition containing, in mass percent, C0.05%, Si1.0%, Mn2.0%, P0.04%, S0.01%, Ni: 12.0 to 27.0%, Cr: 15.0% or more to less than 20.0%, Cu: more than 3 0% to 8.0% or less, Mo: more than 2.0% to 5.0% or less, Nb1.0%, Ti0.5%, Co0.5%, Sn0.1%, W5.0%, Zr1.0%, Al0.5%, N<0.05%, Ca0.01%, B0.01%, and REM0.01%, with the balance: Fe and unavoidable impurities, and the welding structure member including including weld metal having a chemical composition containing, in mass percent, C0.10%, Si0.50%, Mn3.5%, P0.03%, S0.03%, Cu0.50%, Ni: 51.0 to 69.0%, Cr: 14.5 to 23.0%, Mo: 6.0 to 17.0%, Al0.40%, Ti+Nb+Ta4.90%, Co2.5%, V0.35%, and W4.5%, with the balance: Fe and unavoidable impurities.

The present invention provides a tube body that is to be used in a high-temperature atmosphere and a method for stably forming a metal oxide layer on an inner surface of the tube body at a high area percentage.

The tube body that is to be used in a high-temperature atmosphere according to the present invention is constituted by a heat-resistant alloy containing Cr in an amount of 15 mass % or more and Ni in an amount of 18 mass % or more, and on the inner surface, an arithmetic average roughness (Sa) of three-dimensional surface roughness satisfies 1.5?Sa?5.0 and a skewness (Ssk) of a surface height distribution satisfies |Ssk|?0.30. The heat-resistant alloy may contain Al in an amount of 2.0 mass % or more. On the inner surface, a kurtosis (Sku) of a surface height distribution of the three-dimensional surface roughness may satisfy Sku?2.5.

A system for producing chemicals, such as, ethylene or gasoline, at high temperature (above 1100 degrees C.) having a feedstock source. The system includes a chemical conversion portion connected with the feedstock source to receive feedstock and convert the feedstock to ethylene or gasoline. The conversion portion includes a coil array and a furnace that heats the feedstock to temperatures in excess of 1100 C. or 1200 C. or even 1250 C. or even 1300 C. or even 1400 C. A method for producing chemicals, such as ethylene or gasoline, at high temperature.

A system for sealing an internal passage of a component includes a closure element positioned within the internal passage, and a joint material coupling the closure element to at least one passage wall that defines the internal passage. The system also includes a flexible braze element positioned proximate the closure element, the joint material, and the at least one passage wall.

There is provided a welding structure member excellent in corrosion resistance in an environment where high-concentration sulfuric acid condenses, the welding structure member including base material having a chemical composition containing, in mass percent, C0.05%, Si1.0%, Mn2.0%, P0.04%, S0.01%, Ni: 12.0 to 27.0%, Cr: 15.0% or more to less than 20.0%, Cu: more than 3.0% to 8.0% or less, Mo: more than 2.0% to 5.0% or less, Nb1.0%, Ti0.5%, Co0.5%, Sn0.1%, W5.0%, Zr1.0%, Al0.5%, N<0.05%, Ca0.01%, B0.01%, and REM0.01%, with the balance: Fe and unavoidable impurities, and the welding structure member including weld metal having a chemical composition containing, in mass percent, C0.10%, Si0.50%, Mn3.5%, P0.03%, S0.03%, Cu0.50%, Ni: 51.0 to 80.0%, Cr: 14.5 to 23.0%, Mo0.10%, Al0.40%, Ti+Nb+Ta4.90%, Co2.5%, V0.35%, and W4.5%, with the balance: Fe and unavoidable impurities.

A method for forming an article is disclosed, including laser welding a powder of an HTW alloy to a surface of a substrate along a weld path, forming a weld bead of the HTW alloy. The weld path is propagated along a weld direction, forming a cladding layer of the HTW alloy on the surface. The laser welding includes a laser energy density of at least about 11 kJ/cm.sup.2, and laser welding the powder to the surface includes a welding speed of about 5-20 ipm. The weld path oscillates essentially nonparallel to a reference line, establishing a cladding width wider than the weld bead width. The weld bead contacts itself along each oscillation such that the cladding layer is continuous and essentially free of cracks. A turbine bucket is disclosed including a squealer tip having the cladding layer with a cladding layer thickness of at least about 0.2 inches.

A process for producing an amorphous ductile brazing foil is provided. According to one example embodiment, the method includes providing a molten mass, and rapidly solidifying the molten mass on a moving cooling surface with a cooling speed of more than approximately 10.sup.5 C./sec to produce an amorphous ductile brazing foil. A process for joining two or more parts is also provided. The process includes inserting a brazing foil between two or more parts to be joined, wherein the parts to be joined have a higher melting temperature than that the brazing foil to form a solder joint and the brazing foil comprises an amorphous, ductile Ni-based brazing foil; heating the solder joint to a temperature above the liquidus temperature of the brazing foil to form a heated solder joint; and cooling the heated solder joint, thereby forming a brazed joint between the parts to be joined.