Welding Qt Steels. The main concern when welding high strength QT steels is hydrogen assisted cold cracking HACC and heat affected zone HAZ softening. In some cases PWHT can.
P 12 I I I. In addition to the refining and tempering effect on the weld metal of the previous weld pass the smaller heat input of multi pass welding compared with that of single pass welding helps in achieving a fast cooling rate. G4021 Grade 700Q ASTM A 514.
Also preheat should NOT exceed 400F for thickness up to 1-12 or 450F for thickness over 1-12.
The material of the study is QT Steel welded joint made by PT. Also preheat should NOT exceed 400F for thickness up to 1-12 or 450F for thickness over 1-12. G4021 Grade 700Q ASTM A 514. Armour grade QT steel has well established weld compatibility with ASS and HNS consumables and they are used in.