Electron-beam fusion welding of beryllium

Abstract

Ingot-sheet beryllium (Be) having three different chemistries and three different thicknesses was fusion-welded by the electron-beam process. Several different preheats were used to obtain 100 • percent penetration and crack-free welds. Cracking susceptability was found to be related to aluminum (Al) content; the higher Al-content material was most susceptable. However, adequate preheat allowed full penetration and crack-free welds to be made in all materials tested. The effect of a post-weld heat treatment on the _ mechanical properties of these compositions was also determined. The heat treatment produced no significant effect on the ultimate tensile strength. However, the yield strength was decreased and the. ductility was increased. These changes are attributed to the formation of AIFeBe 4 and FeBe 11 •

Numerical Modeling of δ-Ferrite Dissolution Kinetics in Austenitic Stainless Steels

“…Their as-cast microstructure below a certain temperature often exhibits a duplex-phase structure consisting of 8-ferrite and austenite. Unfortunately, the presence of 8-ferrite generally results in a deterioration of high temperature workability and corrosion resistance at room temperature, and introduces a ferromagnetic character to the material [1]. Hence, austenitic stainless steels produced by either conventional slab casting or strip casting, which is a recently emerged technology to produce thin stainless steel strips through a twin-roll casting module with hot rolling processes being omitted, need to undergo dissolution treatments to get the 8-ferrite phase dissolved.…”