The invention provides an electric
smelting forming method of a CAP1400 main steam
pipe penetration piece which is efficient, low in cost and excellent in mechanical properties. According to the method, an electric
smelting head and a substrate are connected to the two poles of a power source; while forming, a
metal raw material wire is conveyed to the surface of the substrate by a conveying mechanism and the electric
smelting head; under the protection of the accumulation of granular accessories, the
electric arc is generated between the
raw material wire and the substrate to melt partial surfacing accessories to form a
molten slag pool; the current flows through the
raw material wire and the
molten slag pool to form resistance heat and electro-
slag heat; under the actions of the three composite high-energy heat sources, namely the
electric arc heat, the resistance heat and the electro-
slag heat, the raw material wire is melted to form a local
molten pool on the surface of the substrate; the raw material wire and the accessories are fed continuously; the relative movement of the electric smelting head and the substrate is controlled by a computer according to the stratified
slicing data of a formed part so as to realize quick cooling and layer-by-layer solidification accumulation of the
molten pool on the substrate, and finally, the main steam
pipe penetration piece is formed by virtue of layer-by-layer accumulation.