Explore more content. Mechanism of solidification cracking during welding of high strength steels for subsea linepipe. Cite Download Weld solidification cracking is an important issue in fusion welding. If undetected, the cracking defects can act as stress concentration sites which lead to premature failure via fatigue, as well as offer favourable sites for hydrogen assisted cracking and stress corrosion cracking.
Solidification of an NH 4 Cl-H 2 O solution in a square cavity with a free surface has been studied numerically and experimentally. Theoretical and experimental results indicate that i surface tension forces spawn a cellular flow at the top of the cavity and enhance its development with increasing time, ii water enrichment of the top cell induces remelting of adjoining solid, and iii final steady-state conditions are characterized by a liquidus front whose thickness increases with increasing depth. However, predicted and observed results differ with respect to the chronological pattern of multicellular flow development and the time required to achieve steady-state conditions. Differences are attributed to selected model assumptions and to uncertainties concerning mushy region structure.
Chahal, Monica. Such a combination of microstructural attributes makes the resulting MPS material well-suited for high-performance electronic and photovoltaic applications. The MPS method was conceived based on a well-known phenomenon of coexisting solid-liquid regions in radiatively-melted Si films on SiO2. Through our investigations, we have discovered that multiple exposures of an initially amorphous precursor in air within the solid-liquid coexistence regime can lead to the generation of such a material. In the course of this thesis, we have also identified the optimal processing conditions for obtaining such a microstructure, as well as the physical factors that control the process.