The invention relates to an
electric arc additive manufacturing method of a conformal cooling passage with a circular cross section. According to the method, the inner surface of a rough machined moldis used as an additive datum plane, a consumable
electrode inert gas protection electric arc additive process is adopted, an internal conformal passage with a circular cross section is manufactured through a specific conformal additive path and a specific angle, a
cooling medium flows in the passage, and a flowing direction is parallel to the inner surface of a mold cavity. The method comprises the following steps of S1, designing a structure of a three-dimensional conformal passage with the circular cross section; S2, partitioning the passage structure, and milling the datum plane of a basebody; S3, carrying out additive manufacturing on the
lower half part of the passage; S4, carrying out additive manufacturing on an inner wall structure and other structures of the upper half part of the passage; and S5,
machining the inner surface of the mold cavity. The
electric arc additive manufacturing method of the conformal cooling passage with the circular cross section provided by the invention adopts a low-cost electric arc additive manufacturing process technology for realizing high-efficient manufacturing of the complicated conformal cooling passage of the large-size mold, and has the characteristics that raw materials are saved, the manufacturing cost is reduced, the mold
cooling efficiency is high, the cooling uniformity is good, and the like.