Heat-affected zone

About: Heat-affected zone is a research topic. Over the lifetime, 18787 publications have been published within this topic receiving 231744 citations.

Reinforced solder, brazing and welding compositions and methods for preparation thereof

Abstract: A solder, brazing or welding composition having improved physical properties, comprising a continuous phase ranging from about 40% to about 99% by volume of a solder, brazing or welding metal or alloy, and a disperse phase ranging from about 60% to about 1% by volume and comprising a reinforcing material in particulate or fibrous form, the reinforcing material being graphite, silicon carbide, a metal oxide, an elemental metal, and/or a metal alloy A process for preparing the composite comprises providing a solder, brazing or welding metal or alloy, melting the metal or alloy, cooling the metal or alloy to a semi-solid state, subjecting the metal or alloy to vigorous shearing while in the semi-state, adding a reinforcing material as defined above to the metal or alloy during at least one of the cooling and shearing steps in an amount ranging from about 60% to about 1% by volume of the total volume, the reinforcing material being and remaining in particulate or fibrous form as a disperse phase, and solidifying the resulting composite The composite may have a non-dendritic microstructure or may be amorphous

Low Temperature Sensitization of Welded Type 304 Stainless Steel

Abstract: It has been shown that the sensitization of Type 304 stainless steel occurs at temperatures well below the normal isothermal temperature range for sensitization. A prerequisite for this low temperature sensitization (LTS) is the presence of chromium carbide nuclei along grain boundaries. This paper shows that the thermal exposure during welding can nucleate the grain boundary carbides necessary for subsequent LTS. Quantitative transmission electron microscopy studies show that no new carbides nucleate during an LTS heat treatment at 400 C. However, carbides that were nucleated at the time of welding grow during the LTS heat treatment. These findings are consistent with the proposed nucleation and growth LTS model. Using an accelerated test for intergranular stress corrosion cracking (IGSCC) in high temperature, high purity, 8 ppm oxygen water, it has been found that the rate of LTS in a Type 304 stainless steel weld heat affected zone obeys an Arrhenius temperature dependence which predicts that ...

Welding method combining laser welding and MIG welding

Abstract: Welding of deep penetration is obtained in a sustrate by a method which comprises first melting the joint portion of the substrates by MIG welding and then focusing a laser beam in the bottom surface of a crater formed in consequence of the MIG welding thereby effecting laser welding of the crater.