Abstract: The invention relates to a method for producing a steel composite in which at least two steel sheets that consist of different steel grades are placed against each other, hot rolled together, and then possibly cold rolled and in which after the rolling, the composite material, which is thus produced from at least two layers with different steel compositions, is diffusion annealed, wherein the annealing temperature is set so as to select the chemical potential of the steel materials to correspond to the following equation: ?C,material 1>?C,material 2, where material 1 has a lower carbon content than material 2 so that an uphill diffusion of carbon takes place between material 1 and material 2.

Abstract: A method of forming an assembly in which a metal extension element is connected with a metal stub element, by an intermediate element. The intermediate element extends between first and second ends. The intermediate element is positioned to locate its first end spaced apart from the stub element. An inner end of the extension element is spaced apart from the second end of the intermediate element. Heating elements are located between the elements, to heat the proximal portions of the elements to a hot working temperature, at which the heated portions are subject to plastic deformation. The heating elements are removed, and while the intermediate element is rotating, the first end is urged against the stub element to bond the intermediate element with the stub element. While the extension element is rotating, the inner end is urged against the second end to bond the extension element and the intermediate element.

Abstract: A method for joining materials such as metal alloys that includes a first component, wherein the first component includes a first alloy having a known austenization temperature below which martensite forms when the component is heated and then cooled at a predetermined rate of cooling; a second component, wherein the second component includes a second alloy; and a welding apparatus operative to create a weld between the first and second components without crossing the austenization temperature of the first alloy.

Abstract: Provided are strain hardened high strength nickel based alloy welds that yield improved properties and performance in joining high strength metals. The advantageous weldments include two or more segments of ferrous or non-ferrous components, and fusion welds, friction stir welds, electron beam welds, laser beam welds, or a combination thereof bonding adjacent segments of the components together, wherein the welds comprise a strain hardened nickel based alloy weld metal composition including greater than or equal to 10 wt % Mo based on the total weight of the nickel based alloy weld metal composition. Also provided are methods for forming the welds from the nickel based alloy weld compositions. The strain hardened high strength nickel based alloy welds are useful in the oil, gas and petrochemical industry in applications for natural gas transportation and storage, oil and gas well completion and production, and oil and gas refinery and chemical plants.

Abstract: This invention concerns a method, materials, and products involving the joining of titanium aluminide to steel by welding each to an iron-based alloy interlayer or connecting piece. The interlayer can be friction welded to the steel and friction welded to the TiAl. The interlayer alloy can be an iron-based superalloy such as A-286. The friction welding of the TiAl to the interlayer can be done in three steps, each with increased pressure between the parts, with a total time of about 30 seconds. Joint strength of 412 MPa can be achieved for a 25.4 mm weld face diameter. The product can be a turbocharger rotor. The connecting piece (4) is composed of an alloy comprising the following composition in weight percent, Ni, less than or equal to 31.99, Fe, greater than 45.69, preferably, Ni, less than or equal to 30, Fe, greater than 50; and optimally, Ni, less than or equal to 28, Fe, greater than 52.