Influences Of Cold Rolling And Annealing On Formability Of HTCR 5052 Aluminum Alloy Sheets

5XXX aluminum alloy is a kind of non heat treated aluminum alloy,with a small specific gravity,high specific strength,good corrosion resistance,weldability and easy processing and other advantages,it is is an important material in transportation industry.5052 aluminum alloy is one of the most widely used 5XXX alloy.High-throughput continuous casting and rolling process(HTCR process)is a new and efficient production technology of aluminum alloy plate blank.The process has the advantages of short process,high production efficiency,energy saving and environmental protection.The internal structure of 5052 alloy sheet produced by High-throughput continuous casting and rolling process is uneven and the performance is not stable for the reason of faster solidification rate of aluminum liquid in continuous casting process and higher temperature reduction rate of plate in continuous hot rolling process.In this paper,6mm thick 5052 alloy sheet produced by High-throughput continuous casting and rolling process was used as experimental material,the effect of intermediate annealing,cross-rolling,cold rolling rate and the final annealing temperature on the microstructure,texture,mechanical property and formability of the finished sheet were researched by microstructure analysis,energy spectrum analysis,macro texture analysis,mechanical properties and formability test.The main results are as follows:1.The microstructure of 6mm thick 5052 alloy sheet produced by continuous casting and rolling process is the rolling structure.After intermediate annealing,the microstructure of the plate changes into recrystallized structure and a large number of fine Al-Fe particles are precipitated in the grain.The 5052 alloy sheet with intermediate annealing was cold rolled to 2mm,it takes shorter time to complete the recrystallization process.The recrystallization activation energy of cold rolled sheet with intermediate annealing is 164.3 KJ/mol,which is 18% lower than cold rolled sheet without intermediate annealing.2.The 5052 alloy cold rolled sheet with 480?×8h intermediate annealing andthe sheet without intermediate annealing both have brass texture,S texture and copper texture component.The maximum strength of rolling texture in the sheet with intermediate annealing is 11,which is 35% lower than the sheet without intermediate annealing.In addition,cube texture component with maximum strength of 5 is obtained in the cold rolled sheet with intermediate annealing.The 5052 alloy recrystallization sheet with intermediate annealing and the sheet without intermediate annealing both have cube texture and S texture component.The maximum strength of recrystallization texture in the sheet with intermediate annealing is 6.6,which is 15%higher than the sheet without intermediate annealing.3.The n value of the 5052 alloy finished sheet with 480 ? ×8h intermediate annealing is 0.396,which is 12.6% higher than the sheet without intermediate annealing.The r value of the 5052 alloy finished sheet with intermediate annealing is0.696,which is 10.5% lower than the sheet without intermediate annealing.The(35)r value of the 5052 alloy finished sheet with intermediate annealing is-0.084,which is54.8% higher than the sheet without intermediate annealing.The cup convex value of the 5052 alloy finished sheet with intermediate annealing is 9.73,which is 1.1%higher than the sheet without intermediate annealing.Compared with the finished sheet without intermediate annealing,the formability of the sheet with intermediate annealing is improved obviously.4.The cold rolling deformation rate and annealing temperature both have significant influence on the mechanical properties and formability of 5052 alloy finished sheet.When the cold rolling deformation rate is 66.7% and the final sheet is annealed at 400? for 3 hours,the tensile strength is 190.8Mpa,the yield strength is86.8Mpa,the elongation is 26%,the mechanical properties are the best;the average n value is 0.409,the average r value is 0.695,(35)r value is-0.08,cup convex value is 9.9,the forming performances are also best.5.The cross rolling sheet contains typical rolling texture components distributed along the ? orientation line,and the direct cold rolling sheet contains typical rolling texture components distributed along the ? orientation line.The maximum texture strength of the sheet with the cross rolling A process is 19,which is 10.5% higherthan the direct cold rolling sheet;the maximum texture strength of the sheet with the cross rolling B process is 23,which is 26.1% higher than the direct cold rolling sheet.The cross rolling finished sheet contains cubic texture and brass texture,and the direct cold rolling finished sheet contains cubic texture and R texture.The cube texture strength of the finished sheet with the cross rolling A process is 2.9,which is47.3% lower than the direct cold rolling sheet;the cube texture strength of the sheet with the cross rolling B process is 2.6,which is 52.7% lower than the direct cold rolling sheet.6.The average n value of the sheet with the cross rolling A process is 0.378,the average n value of the sheet with the cross rolling B process is 0.38,they are 8.9%higher than the direct cold rolling sheet.The average r value of the sheet with the cross rolling A process is 0.77,the average r value of the sheet with the cross rolling B process is 0.764,they are almost same with the direct cold rolling sheet.The(35)r value of the sheet with the cross rolling A process is-0.156,which is 16.1% higher than the direct cold rolling sheet;the(35)r value of the sheet with the cross rolling B process is-0.09,which is 51.6% higher than the direct cold rolling sheet.The convex values of two kinds of cross rolling sheet are 9.7 and 9.67,respectively,which are0.8% higher than the direct cold rolling sheet.Compared with the direct cold rolling sheet,the formability of cross rolling finished sheet is improved significantly.