If homogenizing anneding treatment is not or insufficiently carried out to the 2A12 alloy ingot,the head and of tube ingot will be heavily broken during head flattening before the cold drawing step.

• 2A12合金铸锭如果不进行均匀化退火或均匀化不充分,生产薄壁管时,管坯在冷拔前打头时端头破碎严重,打头困难;