Forming process of Mg-Y-Zn magnesium alloy bar

The invention discloses a forming process of an Mg-Y-Zn magnesium alloy bar. The forming process comprises the following steps that A, the Mg-Y-Zn magnesium alloy bar is smelted and semi-continuously cast; b, the cast ingot is subjected to homogenizing annealing treatment; c, taking out the ingot blank after the homogenizing annealing treatment, air-cooling to room temperature, turning, performing 30-40% upsetting deformation by adopting a hydraulic machine at the pressing speed of 10-50mm/s to obtain an Mg-Y-Zn alloy bar, and machining until the diameter phi is 125-135mm; d, before extrusion, the blank and the mold are subjected to heat preservation for 1-3 h at the temperature of 380-460 DEG C; after heat preservation is finished, an eccentric hole die is adopted for horizontal forward extrusion, the distance between the hole center and the dead center of the die is 20-35 mm, and a bar with the diameter phi being 20 mm is extruded from a die hole; the propelling speed of the hydraulic rod is 0.5-3.5 mm/s; t