Flux cored wire for duplex stainless steel and method of manufacturing the same

A method of manufacturing a flux cored wire for duplex stainless steel including a sheath and a flux filled into the sheath, the method comprising filling a mixed flux into the sheath;

• wherein the flux cored wire comprises about 24.0-30.0 wt % Cr, about 7.0-10.5 wt % Ni, about 2.0-4.0 wt % Mo), about 0.10-2.50 wt % Cu, about 0.40-1.00 wt % Si, about 1.5-3.0 wt % Mn, about 0.10-0.30 wt % N compound (converted value of N), and the remainder including iron (Fe) and inevitable impurities on the basis of a total weight of the wire;
• the flux comprises about 6.50-12.00 wt % of TiO2+SiO2+ZrO2+Al2O3, about 0.10-0.50 wt % of Li2O+K2O+Na2O, about 0.10-2.00 wt % of other oxides, and about 0.10-0.50 wt % of metal fluoride (converted value of F) on the basis of the total weight of the wire;
• and
• the flux is filled into the sheath at a ratio of about 26-35%.

A method of manufacturing a flux cored wire for duplex stainless steel including a sheath and a flux filled into the sheath, the method comprising filling a mixed flux into the sheath;

• wherein an apparent density of the mixed flux is about 3.50 g/L to about 4.50 g/L;
• and wherein particles of the mixed flux can all pass through a 60-mesh standard sieve;
• and wherein a ratio of the particles of the mixed flux which cannot pass through a 230-mesh standard sieve to the particles of the mixed flux with can pass through a 230-mesh standard sieve is from about 65% to about 85%;
• wherein the flux cored wire comprises about 24.0-30.0 wt % Cr, about 7.0-10.5 wt % Ni, about 2.0-4.0 wt % molybdenum), about 0.10-2.50 wt % Cu, about 0.40-1.00 wt % Si, about 1.5-3.0wt % Mn, about 0.10-0.30 wt % N compound (converted value of N), and the remainder including iron (Fe) and inevitable impurities on the basis of a total weight of the wire;
• the mixed flux comprises about 6.50-12.00 wt % of TiO2+SiO2+ZrO2+Al2O3, about 0.10-0.50 wt % of Li2O+K2O+Na2O, about 0.10-2.00 wt % of other oxides, and about 0.10-0.50 wt % of metal fluoride (converted value of F) on the basis of the total weight of the wire;
• and
• the mixed flux is filled into the sheath at a ratio of about 26-35%.