| 摘要 |
<p>A basic type flux-cored wire for gas shielded arc welding of the present invention comprises a steel sheath and a basic type flux composition filled in the steel sheath. The basic type flux composition contains, based on the weight of the total wire, one kind or two or more kinds selected from a group consisting of fluorides of Ca, Ba, Mg and Sr in the total amount of from 0.5 to 3%; one kind or two or more kinds selected from a group consisting of carbonates of Ca, Ba and Sr and complex oxides thereof in the total amount of from 0.5 to 3%; one kind or two or more kinds selected from a group consisting of fluorides, oxides and carbonates of alkali metals in the total amount of from 0.01 to 0.1%; and an iron powder in an amount of from 1.3 to 37.5%. The basic type flux composition and/or the steel sheath contain 1.0 to 2.5% of Mn and 0.4 to 1.4% of Si based on the weight of the total wire. Further, the amounts of the metal powders and non-metal powders contained in the basic type flux composition satisfy a relation of (metal powders/non-metal powders >/= 2), and the amounts of Mn and Si contained in the basic type flux composition and/or the steel sheath satisfy a relation of (1.0 </= Mn/Si </= 2.5). Optionally, the above flux composition and/or the steel sheath may contain, based on the weight of the total wire, Ti and/or Ti oxide in the total amount of 0.01 to 0.10% (calculated as TiO2), and the basic type flux composition may contain 0.08 to 1.5% of Mg based on the weight of the total wire. With this construction, it is possible to provide the basic type flux-cored wires for gas shielded arc welding capable of enhancing the usability characteristics without degrading the crack resistance and the low-temperature toughness, and of being used in either polarity of DC-EN and DC-EP.</p> |
