Preparation of superstructure welding instructions and operations the upper and lower frame of the roof of the electric arc furnace of the steelmaking unit

In this research, CEN ISO / TR 15608 sheet with a thickness of 25 to 40 mm was used by various types of corner and groove welding of this complex section for superstructure ofthe upper and lower frame of the electric arc furnace roof of the steelmaking unit with desirable quality and without complexity. Special instructions for welding. Heavy dutywelding, non-distortion and cracking is an important issue that requires control of base metals, welding materials, preheating and other factors. Quantum analysis was used toaccurately determine the chemical composition of the sheet. According to the prepared welding instructions, a special electrode E7018-1 H4R with a diameter of 3.25 to 4 mmwas used due to the precise control of dilution and temperature between passes,otherwise there was a possibility of freezing cracks in the welded parts. Reducing thelevel of residual stresses resulting from welding at the joint and facilitating the removal of hydrogen was the most important task. Finally, the welded part was delivered afterdimension mapping for non-complexity with an accuracy of 0.2 mm and non-destructive testing was performed in all stages to evaluate the quality and health of the welds

Keywords:

Preheating , Welding instructions , Filler metal E7018-1 H4R , Distortion