A Forming Process of Large-diameter, Medium-Strength, and Heat-resistant Magnesium Alloy Thick-walled Cylindrical Parts

Abstract

The invention discloses a large-diameter moderately-strong heat-resisting magnesium alloy thick-wall barrel-shaped piece forming process. The process includes the steps of large-furnace smelting, semi-continuous casting, homogenizing annealing, varying-temperature multi-direction forging, mechanical punching, ring rolling forming and aging treatment. The varying-temperature multi-direction forging is conducted on an oil press, pressing speed is 200-400mm / min, upsetting reduction in pass is 30-40%, drawing down reduction in pass is 5-10%, blank before ring rolling forming is kept at the temperature of 380-400 DEG C for 4-8 hours, and rolling deformation is 60-80%. The thick-wall barrel-shaped piece 700-1100mm in outer diameter, 50-100mm in wall thickness and 300-700mm in height is manufactured. The thick-wall barrel-shaped piece is high in strength and good in heat resistance and meets size and performance requirements of structural parts in the aerospace field.

Description

technical field

[0001] The invention relates to the field of deformation processing of magnesium alloys, in particular to the field of forging and ring rolling deformation of a Mg-Al-Ag magnesium alloy. Background technique

[0002] At present, large-diameter thick-walled cylindrical parts, as important structural parts in the aerospace field, are made of aluminum alloys. With the rapid development of the aerospace field, material weight reduction has become an urgent requirement in this field. If these large-diameter thick-walled cylindrical parts are made of magnesium alloys, significant weight reduction can be achieved (magnesium alloys are one-third lighter than aluminum alloys). It is difficult to prepare thick-walled cylindrical parts from magnesium alloys. Magnesium alloy has a close-packed hexagonal crystal structure with few slip systems and poor deformation ability at room temperature; the thermal deformation temperature range is narrow and the heat dissipation i...

Examples

Embodiment 1

[0023] Example 1: Using a large furnace to melt raw materials, a Mg-8.0Al-0.5Ag-0.4Zn-0.1Mn-0.1RE-0.01Ca (wt.%) magnesium alloy ingot with a diameter of Ф530mm was cast by semi-continuous casting. The ingot is processed by mechanical car skin, cutting, chamfering, etc., and finally an ingot with a diameter of Ф480mm and a length of 700mm is processed, such as figure 1 shown. The ingot is subjected to bipolar homogenization annealing. The annealing process is as follows: after holding at 250-300 °C for 10-12 hours, the temperature is raised to 380-410 °C for 20-30 hours, and air-cooled to room temperature. The ingot is heated to 410°C for 10 hours, and the ingot is forged by upsetting and multi-directional forging on a hydraulic press. The amount is 5-10%, and the temperature of the upper and lower cutting boards is 150-200 °C. During the forging process, when the surface temperature of the ingot is lower than 350 ℃, it is annealed back to the furnace, and the annealing tempe...

Embodiment 2

[0024] Example 2: First, use a large furnace to melt the alloy raw materials, and then semi-continuously cast a Mg-8.0Al-0.5Ag-0.4Zn-0.1Mn-0.1RE-0.02Ca (wt.%) alloy ingot with a diameter of Ф550mm. The ingot is processed by mechanical turning, cutting, chamfering, etc., and finally an ingot with a diameter of Ф500mm and a length of 780mm is processed. The ingot is subjected to bipolar homogenization annealing. The annealing process is as follows: after holding at 250-300 °C for 10-12 hours, the temperature is raised to 380-410 °C for 20-30 hours, and air-cooled to room temperature. The ingot was kept at 400°C for 16 hours, and the ingot was forged by upsetting and multi-directional forging on a hydraulic press. -10%, the temperature of the upper and lower cutting boards is 150-200℃. During the forging process, when the surface temperature of the ingot is lower than 350 ℃, it is annealed back to the furnace, and the annealing temperature is 390 ℃ and the holding time is 8h. E...

Embodiment 3

[0025] Example 3: First, use a large furnace to melt the alloy raw materials, and then semi-continuously cast a Mg-9.0Al-0.8Ag-0.4Zn-0.1Mn-0.1RE-0.01Ca (wt.%) magnesium alloy ingot with a diameter of Ф600mm. The ingot is processed by mechanical car skin, cutting, chamfering, etc., and the final ingot size is Ф550mm in diameter and 650mm in length. The ingot is subjected to bipolar homogenization annealing. The annealing process is as follows: after holding at 250-300 °C for 10-12 hours, the temperature is raised to 380-410 °C for 20-30 hours, and air-cooled to room temperature. Upsetting and drawing multi-directional forging is performed on the ingot on a hydraulic press, with a reduction speed of 200-400mm / min, a reduction of 30-40% for upsetting passes, a reduction of 5-10% for elongated passes, and the temperature of the upper and lower anvils. 150-300℃. The ingot was heated to 410°C for 8h before forging. During the forging process, when the surface temperature of the in...

technical field

[0001] The invention relates to the field of deformation processing of magnesium alloys, in particular to the field of forging and ring rolling deformation of a Mg-Al-Ag magnesium alloy. Background technique

[0002] At present, large-diameter thick-walled cylindrical parts, as important structural parts in the aerospace field, are made of aluminum alloys. With the rapid development of the aerospace field, material weight reduction has become an urgent requirement in this field. If these large-diameter thick-walled cylindrical parts are made of magnesium alloys, significant weight reduction can be achieved (magnesium alloys are one-third lighter than aluminum alloys). It is difficult to prepare thick-walled cylindrical parts from magnesium alloys. Magnesium alloy has a close-packed hexagonal crystal structure with few slip systems and poor deformation ability at room temperature; the thermal deformation temperature range is narrow and the heat dissipation i...

Examples

Embodiment 1

[0023] Example 1: Using a large furnace to melt raw materials, a Mg-8.0Al-0.5Ag-0.4Zn-0.1Mn-0.1RE-0.01Ca (wt.%) magnesium alloy ingot with a diameter of Ф530mm was cast by semi-continuous casting. The ingot is processed by mechanical car skin, cutting, chamfering, etc., and finally an ingot with a diameter of Ф480mm and a length of 700mm is processed, such as figure 1 shown. The ingot is subjected to bipolar homogenization annealing. The annealing process is as follows: after holding at 250-300 °C for 10-12 hours, the temperature is raised to 380-410 °C for 20-30 hours, and air-cooled to room temperature. The ingot is heated to 410°C for 10 hours, and the ingot is forged by upsetting and multi-directional forging on a hydraulic press. The amount is 5-10%, and the temperature of the upper and lower cutting boards is 150-200 °C. During the forging process, when the surface temperature of the ingot is lower than 350 ℃, it is annealed back to the furnace, and the annealing tempe...

Embodiment 2

[0024] Example 2: First, use a large furnace to melt the alloy raw materials, and then semi-continuously cast a Mg-8.0Al-0.5Ag-0.4Zn-0.1Mn-0.1RE-0.02Ca (wt.%) alloy ingot with a diameter of Ф550mm. The ingot is processed by mechanical turning, cutting, chamfering, etc., and finally an ingot with a diameter of Ф500mm and a length of 780mm is processed. The ingot is subjected to bipolar homogenization annealing. The annealing process is as follows: after holding at 250-300 °C for 10-12 hours, the temperature is raised to 380-410 °C for 20-30 hours, and air-cooled to room temperature. The ingot was kept at 400°C for 16 hours, and the ingot was forged by upsetting and multi-directional forging on a hydraulic press. -10%, the temperature of the upper and lower cutting boards is 150-200℃. During the forging process, when the surface temperature of the ingot is lower than 350 ℃, it is annealed back to the furnace, and the annealing temperature is 390 ℃ and the holding time is 8h. E...

Embodiment 3

[0025] Example 3: First, use a large furnace to melt the alloy raw materials, and then semi-continuously cast a Mg-9.0Al-0.8Ag-0.4Zn-0.1Mn-0.1RE-0.01Ca (wt.%) magnesium alloy ingot with a diameter of Ф600mm. The ingot is processed by mechanical car skin, cutting, chamfering, etc., and the final ingot size is Ф550mm in diameter and 650mm in length. The ingot is subjected to bipolar homogenization annealing. The annealing process is as follows: after holding at 250-300 °C for 10-12 hours, the temperature is raised to 380-410 °C for 20-30 hours, and air-cooled to room temperature. Upsetting and drawing multi-directional forging is performed on the ingot on a hydraulic press, with a reduction speed of 200-400mm / min, a reduction of 30-40% for upsetting passes, a reduction of 5-10% for elongated passes, and the temperature of the upper and lower anvils. 150-300℃. The ingot was heated to 410°C for 8h before forging. During the forging process, when the surface temperature of the in...

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