The invention relates to the cast steel industry, particularly to a process for repair-
welding a
steel casting through flux-cored wire CO2 gas shielded
welding. During the application, the process for repair-
welding steel casting products is characterized by selecting a flux-cored wire matched with a
casting base material, determining
welding process parameters reasonably, selecting a welding current of 150-300 A, a welding
voltage of 23-40 V, a wire extension length of 15-25mm, a welding speed of 45-90 mm / s, a gas flow of 20-25 L / min, and performing WPQ (welding procedure qualification ) according to the IX volume of ASME (American Society of Mechanical Engineers). The process for repair-welding the
steel casting through the flux-cored wire CO2 gas shielded welding solves the problem of low efficiency, high labor intensity, multiple joints and
slag removal difficulty of manual SMAW (
shielded metal arc welding), eliminates defects such as microcracks,
porosity and
slag inclusion of a repair-welding area, when compared with the SMAW, can improve the working efficiency to 3-5 times, reduces production costs to more than 50%, enables the
hydrogen content of
weld metal to be lower than 2.0 ppm and
corrosion resistance to be strong, guarantees that physical and chemical properties accord with and exceed requirements of corresponding cast steel material standards, and is applicable to high-grade, precise and top-notch steel castings and steel castings of
high pressure hydrogen valves.