flux composition for a flux - cored wire to be used for welding and surfacing steels with the gas - shielded process comprises flux ingredients in the following amounts , by weight %: rutile concentrate : 20 - 53 ferromanganese : 10 - 22 . 8 ferrosilicon : 1 . 3 - 6 sodium fluosilicate : 1 - 5 calcined magnesite : 1 . 3 - 10 electrocorundum : 1 . 6 - 7 . 5 iron powder : balance .