Effects of magnesium and heat treatment on ears in deep drawing of rolled 2S aluminum sheets

Abstract

It was found that production of ears in deep drawing of rolled sheets depended upon directional properties of the sheets and the orange peel effect of cup depended upon the effects of additional elements and grain size. The directional properties of rolled sheets depended upon many factors such as additional elements, reduction ratio, intermediate annealing, final annealing, etc.The authors investigated the relation between ears and orange peel effect or heat treatment on rolled 2S sheets containing magnesium.The results obtained were summarized as follows.(1) In the specimen containing 0.20% of Mg, grain size was larger and orange peel effect was observed. On the other hand, in the specimen containing 0.57% of Mg, the height of ears was less in both directions of 45° and 0-90°.(2) In the specimen which had been treated and held for a long time at higher soaking temperature, ears had a tendency to be produced in 45° direction. On the contrary, in the specimen which had been treated and held for a shorter time at lower soaking temperature, it had a tendency of orange peel effect.(3) In the specimen which had intermediately been annealed at higher draft in hot working (draft of 99.8%), higher cars were produced in 0-90° direction with orange peel effect. However, in the specimen which had not intermediately been annealed, ears produced in 45° direction were higher with no orange peel effect. These results corresponded well with those of pole figures.(4) When the reduction ratio in cold working was larger, the ears produced in 45° direction were higher and when the reduction ratio was smaller, orange peel effect was observed.