Negative Influence by Three-roll Expanding/Piercing Process on Steel Tube Surface Quality

Based on analysis of negative influence by the three-roll expanding/piercing process on steel tube surface quality and relevant experimental proofs, it is concluded that the three-roll expanding/piercing process makes it rather difficult to get desirable metal deformation and flow, and that increasing the tube diameter expansion rate results in severe additional deformation, thus considerably weakening the tube surface quality.