Nilai Ketangguhan dan Bentuk Struktur Mikro dari Perubahan Kuat Arus pipa Spiral

Submerged Arc Welding is a welding process used for fabrication of pipes, for example spiral welded pipes. The technique can be operated automatically and has a high reliability in many various welding aplication. Some factor affecting the strength of weld metals are heat input, current, chemical composition of filler and flux, welding speed and cooling rate.
The purpose of this reased is to obtaine micro structure containing acicular ferrite which give high toughness of the submerged arc welded pipes.
Material used in this experiment was API 5L X-52 spiral welded steel pipes, Welding was carried out using voltage of 35 volt, welding speed of 13,67 mm/s whereas current was varied, namely 800 Amper, 825 Amper, 850 Amper, 875 Amper and 900 Amper. A series of mechanical properties test were carried out
including micro structure form and toughness.
The result show that, an increase in weld current make increased the amount of acicular ferrite and toughness number is increase.