Quenched And Residual Stress Of High Strength Aluminum Alloy Plate

The high strength aluminum alloy thick plate with a small proportion, theintensity ratio of specific strength and specific stiffness of a series of advantages,is widely used in aerospace, weapons, equipment, and automobile industries inrecent years. Thick aluminum alloy plate after solid solution quenching afteraging a large number of dispersion strengthening precipitates may be its strengthsignificantly improved. Intense cooling process is very easy in the slab togenerate serious residual stress of quenched, so that the thick plate bending andwarpage in the subsequent machining, will also affect the dynamic use of thematerial properties such as fracture toughness, stress corrosion resistance and soon. Therefore, in order to meet the needs of industry, control the size of theresidual stress of quenched very great practical significance. Using the finiteelement analysis methods, the use of the quenching process of deform softwaresimulation of thick aluminum alloy plate, quenching temperature distribution atthe same time point tracking technology to quench curve, quenching residualstress distribution field; System to study the residual stress after quenching thealloy plate to eliminate the process, specific research contents and results:1. X-ray diffraction method measured by the residual stress correctionprocess, the residual stress distribution plate surface along the thicknessdirection. The results showed that the plate along the thickness direction sidesurface of the central part of the stress is tensile stress, its maximum tensilestress is located from the upper surface of130mm at76MPa;Plates near thesurface at the upper and lower stress are basically compressive stress, themaximum compressive stress is located in the lower surface of the platesat-113MPa.2. Using finite element software deform-3D simulation of the aluminumalloy plate quench process, the quenching temperature distribution while takingadvantage of tracking technology to quench curve, quenching residual stressdistribution field. Plates inside and outside in the quenching process there is alarge temperature gradient, the maximum temperature gradient of up to370°C. When quenched to500s.The Enthusiasm of temperature would make the board alot of residual stress after quenching. After quenching, the residual stress in theplate on the performance of the outside pressure is within the pull. Themaximum compressive stress at the surface of the plates is-150MPa; themaximum tensile stress in the plates near the core part, as153MPa.Plates afterquenching, the residual stress of the three-way is within the pull externalpressure. In the long generous direction, mainly due to the role of the X to theresidual stress, Y, and Z to the residual stress is very small.3. Using the Deform-3D simulation of the plates of pad compressionmethod to eliminate the quenching residual stress of the process, optimizing thecontrol parameters of the pad width and reduction. To develop the pros and consof the direction pad compression plates to eliminate the residual stress of theprocess program, and the compression process was simulated. The analysis hasbeen both positive and negative direction pad compression plates residual stressdistribution through a point of tracking technology. The results showed that forthe first time under the pressure of the pressure2.4mm3.6mm and then reversethe residual stress of the enable the board to get better control. When first using3.6mm compression, available to board a smaller residual stress values largeror smaller this critical amount of compression is not conducive to effectivecontrol of residual stress.2.4mm after the pressure of the second reverse, theboard of the X direction stress component value as a whole has become moreuniform; compressive stress on the side reduced to zero-57MPa-135MPa, centralto the under surface of the tensile stress reduced to less than45MPa.