| Popis: |
Six 56" × 19.8 mm, API X70 PSL2 pipes were produced from three different plate suppliers and then three samples in pipe transverse direction and perpendicular to welding seam were taken out from welding area of each supplier. Sampling carried out from weld metal, HAZ and base metal of each sample, then all 27 prepared samples were analyzed. Afterwards the amounts of 14 alloying elements were considered. The results showed that content of Carbon, Sulfur, Boron, Phosphorous, Copper, Manganese, Aluminum, Titanium and Molybdenum have been increased in the HAZ and Silicon, Nickel, Chrome, Vanadium and Niobium decreased. So it is predicted that an increase in Carbon, Aluminum, Phosphorous, Sulfur and Boron content, also a decrease in Silicon, Chrome and Nickel will cause a drop in the HAZ toughness and an increase in Titanium, Manganese, Copper and Molybdenum content, also decrease in Vanadium and Niobium will cause a rise in HAZ toughness. |
