Forging and rolling integrated manufacturing process of large-diameter ultrahigh-strength high temperature resisting magnesium alloy shell part

[0024] Example 1

[0025] First, semi-continuous electromagnetic casting is used to prepare an ingot with a diameter of φ400mm and a length of 2500mm, with a composition of Mg-9.20Gd-2.90Y-0.20Ag-0.05Er-0.39Zr (wt.%). After the casting is completed, it is annealed at 225℃ for 14h. , The ingots with a diameter of φ380mm and a length of 800mm were machined out, and the temperature was kept at 520℃ for 15h for homogenization annealing. The ingot is forged and billeted. Before forging, the ingot is kept at 490°C for 10 hours. The upper and lower anvils are heated to 350°C, and the ingot is forged and deformed at a slow speed of 10mm/s on a vertical hydraulic press. The specific process is: Take the height direction of the cylindrical blank and the two arbitrarily vertical radial directions respectively as the Z, Y and X directions; first, perform 6 passes along the Z, Y and X directions, the pass deformation is 30%, and the cylindrical The blank is pressed into a hexahedron; then, using Y or X as the axis, roll and compress the edges and corners for 4 passes, the deformation of each pass is 20%, and the hexahedron is pressed into a 14-hedron; finally, the upsetting is upset and the reduction is 25%. Press into an approximate cylinder. Reheat to 480℃ for 1h. After being out of the furnace, repeat the forging process with the height direction of the new cylinder and any two vertical radial directions as Z, Y and X, and finally press it into an approximate cylinder with a height of 330mm. After forging, it is air-cooled to room temperature. Machine perforated at the center of the blank, the hole size is φ260mm. After holding at 480°C for 6 hours, the ingot is formed by one-shot ring rolling on the rolling mill. During rolling, the driving roll speed is 10r/min, the core roll linear feed speed is 0.4mm/s, and the taper roll is reduced in the high direction. The diameter is 2mm, the rolling deformation is 54%, the roll temperature is 250℃, and the outer diameter is 941mm, the height is 328mm, and the wall thickness is 74mm. The shell is air-cooled to room temperature. Carry out T6 treatment on the shell parts, the solution treatment system is 430℃ heat preservation for 1h, and then carry out 48h aging heat preservation at 210℃. The tensile mechanical properties of T6 state are listed in Table 1.

[0026] Example 2

[0027] First, semi-continuous electromagnetic casting is used to prepare ingots with a diameter of φ450mm and a length of 2500mm with a composition of Mg-8.92Gd-2.23Y-0.28Ag-0.12Er-0.36Zr (wt.%), such as figure 1 As shown, the stress-relieving annealing is kept at 200°C for 16 hours, and an ingot with a diameter of φ420mm and a length of 1075mm is machined out, and the ingot is subjected to homogenization annealing at 490°C for 20 hours. The ingot is forged and billeted. Before forging, the ingot is kept at 520°C for 10 hours, the upper and lower flat anvils are heated to 325°C, and the forging deformation is carried out at a slow speed of 6mm/s on a vertical hydraulic press. The specific process is as follows: The height direction of the blank and the two arbitrarily vertical radial directions are respectively the Z, Y and X directions; firstly, the upsetting is carried out 3 passes along the Z, Y and X directions with a pass deformation of 40%, and the cylindrical blank is pressed into Hexahedron; then take Y or X as the axis, roll and compress the edges and corners 6 passes, with 20% deformation of each pass, and press the hexahedron into an 18-hedron; finally stand up and upset, and press it down by 20% to approximate Cylinder. Reheat to 510℃ for 0.5h. After being out of the furnace, repeat the forging process with the height direction of the new cylinder, and any two vertical radial directions as Z, Y and X directions. After forging, return to the furnace for 1 hour at 500°C, repeat the forging process after the furnace is released, and finally press it into an approximate cylinder with a height of 490mm, and cool to room temperature in air. The hole size is φ265mm in the center of the ingot. After holding the ingot at 510°C for 6 hours, the ingot is ring-rolled twice on the ring rolling mill. During rolling, the driving roller speed is 12r/min, and the core roller linear feed speed is 0.2mm/s. The deformation of the first ring rolling is 20%, the reduction of the tapered roll in the high direction is 3mm, and the roll temperature is 250°C. After the first ring rolling, enter the furnace at 500°C for 1h, the second ring rolling deformation is 55%, the height reduction of the tapered roll is 3mm, the roll temperature is 280°C, the rolled outer diameter is 1200mm, and the height is 484mm. Shell parts with a wall thickness of 60mm, air-cooled to room temperature. See specific physical objects image 3 left. T6 treatment is carried out on the shell parts, the solution treatment system is 410℃ for 2h, and the aging system is 225℃ for 12h. The tensile mechanical properties of T6 state are listed in Table 1.

[0028] Example 3

[0029] First, semi-continuous electromagnetic casting is used to prepare ingots with a diameter of φ450mm and a length of 2500mm, with a composition of Mg-8.71Gd-2.64Y-0.25Ag-0.12Er-0.35Zr(wt.%), and heat-relief annealing at 250℃ for 14h, and mechanical processing An ingot with a diameter of φ420mm and a length of 1075mm is produced and homogenized and annealed at 500℃ for 15h. The ingot is forged and billeted. Before forging, the ingot is kept at 510°C for 12h, the upper and lower anvils are heated to 300°C, and then 8mm/s slow multi-directional forging is performed on a vertical hydraulic press. The specific process is as follows: The two radial directions in the height direction and any vertical direction of the shaped blank are respectively Z, Y and X directions; firstly, the upsetting is carried out 4 passes along the Z, Y and X directions, with a pass deformation of 35%, and the cylindrical blank is pressed Turn into a hexahedron; then use Y or X as the axis to roll and compress the edges and corners for 4 passes, the deformation of each pass is 15%, and the hexahedron is pressed into a 14-hedron; finally, the upsetting is upset, the reduction is 20%, and it is pressed into Approximately cylinder. Reheat to 510℃ for 1.5h. After being out of the furnace, repeat the above forging and annealing process twice with the height direction of the new cylinder and any two vertical radial directions as Z, Y and X, and finally press it into an approximate cylinder with a height of 500mm. After forging, air-cool to room temperature. , See in kind figure 2 中7#. The center of the blank is mechanically perforated, and the hole size is φ270mm. After holding the ingot at 490°C for 6 hours, the ingot was ring-rolled 3 times on the ring rolling mill. During rolling, the driving roll speed is 16r/min, and the core roll linear feed speed is 0.2mm/s. The deformation of the first rolling is 20%, the reduction of the tapered roll in the high direction is 2mm, the temperature of the roll is 270℃, and the first ring rolling is completed and returned to the furnace for 1 hour at 480℃. The deformation of the second rolling is 42%, the reduction of the tapered roll in the high direction is 3mm, the temperature of the roll is 290℃, and the second ring rolling is completed and returned to the furnace at 470℃ for 1.5h. The deformation of the third rolling is 42%, the height reduction of the tapered roll is 3mm, the temperature of the roll is 300℃, the outer diameter is 1700mm, the wall thickness is 35mm, and the height is 492mm. The shell is air-cooled to room temperature. See specific physical objects image 3 right. T6 treatment is performed on the shell parts, the solution treatment system is 410℃ for 1.5h, and the aging process is 230℃ for 12h. The tensile mechanical properties of T6 state are listed in Table 1.

[0030] Table 1 Mechanical properties of magnesium alloy shell parts in examples

[0031]