Process method for improving comprehensive mechanical property of 2219 aluminum alloy ring piece

Abstract

The invention relates to the technical field of metal material deformation heat treatment processes and discloses a process method for improving the comprehensive mechanical property of a 2219 aluminum alloy ring piece so that coarse residual crystalline phases of the large-size 2219 aluminum alloy ring piece can be fully crushed and crystalline grains can be refined and equiaxed, thus, the strength and the plasticity of the 2219 aluminum alloy ring piece are improved at the same time, and the anisotropy is decreased. The process method comprises the steps of multi-directional forging, punching, mandrel supporter broaching, piecewise rolling and heat treatment. In the multi-directional forging step, the heating temperature of a blank is 500 DEG C-520 DEG C, and the final forging temperature is higher than or equal to 380 DEG C. Piecewise rolling comprises the steps that in the first stage, the ring blank is heated to 420 DEG C-460 DEG C and subjected to hot rolling on a ring rolling machine, and the hot rolling deformation quantity is 30%-40%; and in the second stage, the ring piece subjected to hot rolling is air-cooled to 240 DEG C-280 DEG C and is continuously subjected to medium and low temperature rolling on the ring rolling machine, and the deformation quantity is 15%-25%.

Description

technical field [0001] The invention relates to the technical field of deformation heat treatment of metal materials, in particular to a process method for improving the comprehensive mechanical properties of a 2219 aluminum alloy ring. Background technique [0002] 2219 aluminum alloy is an Al-Cu-Mn alloy, which has good high and low temperature mechanical properties, welding performance and fracture toughness. 2219 aluminum alloy is fully used in the storage tanks of my country's active launch vehicles. With the development of my country's heavy-duty launch vehicle, its structural scale continues to increase, and the outer diameter of the transition ring for the storage tank reaches The ingot diameter required for forming is over The solidification cooling rate of super-large ingots is low, and the cooling rate along the radial direction is not uniform. In addition, the Cu element content in 2219 aluminum alloy reaches 5.8-6.8%, which exceeds the limit solubility, so th...

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Problems solved by technology

But if this process is used to manufacture large-scale 2219 aluminum alloy rings, there are the following problems: (1) there are 5 procedures in the C-TMT process, the process route is long, and the operation is complicated, which is not conducive to the industrial production of large-scale rings; 2) The C-TMT process adopts the continuous rolling (cooling while rolling) process to obtain deformation storage energy for the 7000 series thin plate, which utilizes the characteristics of fast cooling speed during the deformation process of the thin plate, and cannot adapt to large sizes and slow temperature drop during the forming process (3) The continuous rolling deformation of C-TMT process reaches 50-90%, while there are a large number of coarse residual crystal phases in the 2219 aluminum alloy, and the size of the ring is large, and the large deformation Low-temperature deformation will cause the risk of deformation and cracking of the ring; (4) C-TMT process uses short-term (10-60min) recrystallization and solid solution to achieve grain refinement of 7000-series aluminum alloy sheet, but the 2219 aluminum alloy has A large number of coarse residual crystalline phases, short-term recrystallization and solid solution cannot achieve sufficient solid solution of coarse residual crystalline phases, which will lead to a decrease in the mechanical properties of the material

However, the treatment method of strong cold deformation by equal radial extrusion is difficult to apply to the industrial production of large forgings, and this process also uses short-term recrystallization and solid solution to achieve grain refinement, which cannot fully realize the residual crystalline phase of 2219 aluminum alloy. Solid solution is not conducive to the improvement of the performance of large 2219 aluminum alloy rings

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