温度对01420铝锂合金轧制开裂及晶粒细化的影响

Effects of Temperatures on Rolling Failure and Grain Refinement of 01420 Al-Li Alloy

采用形变热处理方法制备了01420铝锂合金细晶板材,研究了预热温度、中间退火温度对板材轧制开裂及晶粒细化的影响。结果表明：板材在低温（〈300℃）轧制时常常开裂,将开轧温度提高到400℃,在53%～70%轧制变形量后将板材在340～400℃退火2h,可解决开裂问题。但中间退火温度对最终的再结晶晶粒大小有很大影响：温度为400℃时,合金发生了明显的部分再结晶,位错密度大大降低,虽获得了82%变形量的无开裂的板材,但再结晶后的晶粒粗大,平均晶粒尺寸约为16μm。温度为340、370℃时,合金发生了回复,无明显的再结晶发生,且退火温度越低,所保留的位错密度越高,81%轧制变形量的合金再结晶晶粒尺寸约为11μm。

Fine grained 01420 Al-Li alloy sheet was produced by thermo-mechanical processing. The effects of preheating temperatures, intermediate annealing temperatures on failure and grain refinement of 01420 Al-Li alloy plate were investigated. The results show that roiling at low temperatures （〈300℃） usually lead to a failure of the plate. Enhancing the preheating temperature to 400℃ and annealing the plate at 340～400℃, 2h at 53%～70% in rolling reductions, the failure in plate can be avoided. However, the annealing temperatures have significant influences on the final recrystallized grain size. Annealing at 400℃, although any crack in the sheet did not appear after 82% rolling reduction, the density of dislocations decreased as a result of partially recrystallization occurrence, which results in a coarse grain structure with about 16 μm in grain size after recrystallization. Reheated at 340℃ or 370℃, recovery occurs rather than recrystallization, and higher density of dislocations can be remained when annealing at 340℃, the grain size of the sheet with 81% rolling reduction after recrystallization is about 11 μm.