| 摘要 |
PURPOSE:To improve the feedability of a flux cored welding wire, the deviation at the preceding end of the wire and the moisture absorption resistance thereof by limiting the ratio of the sectional area in the sheath of said wire to the entire sectional area of the wire and preventing the remaining of an opening part in the sheath part. CONSTITUTION:After a flux is packed in a steel pipe, the pipe is drawn to a required size. Thus there is no opening part 8 in a sheath part 9. In the section of the welding wire, the ratio of the sectional area of the sheath to the entire sectional area of the wire is set at 0.55-0.85. Further the wire is subjected to applying a metallic film on the surface of the welding wire or allowing the lubricative fats and oils in the stage of wire drawing to remain at 0.2-1.5gr per 10kg the wire on the wire surface. The reasons for limiting the area ratio lie in this range if the ratio is below 0.55 the wire breaks even when bent slightly and has poor feedability. On the other hand, if the ratio exceeds 0.85, the absolute quantity of the packed flux and the alloy quantity are deficient and the required strength, toughness and coverage of bead surfaces with slag are degraded. |
