Observations on the near-nozzle behavior of an unsteady fuel spray through single cylindrical hole nozzle were made by phase Doopler anemometer and microphotographs. At the edge of the spray, droplet velocities have shown wave-like behavior. The average droplet velocity peaked during needle opening and closing. Droplet sizes tended to be small on the edge of spray. The near-nozzle spray angle taken from the micropho-tographs was time-dependent, even though it increased with gas-to-liquid density ratio as expected. The near-nozzle spray angle was the greatest on the initial stage arid decreased to a relatively constant value after about one third of the total injection duration regardless of the ambient gas conditions. even in the near-vaccum condition. The wider near-nozzle spray angle in the early stage is due to the flow characteri-stics inside the nozzle rather than aerodynamic interactions. However, once the spray was established, aerodynamic interactions are essential in the near-nozzle atomization.
Two metal cored composite wires were manufactured to satisfy AWS F7A4-EC-G specification. They were used to weld EH36 grade steels with three different fluxes. Variation of carbon, manganese, silicon, titanium, and boron contents which affect the weld metal strength in weld metal was investigated.