缩孔是大型铸锻件中常发现的宏观缺陷,一般存在于钢锭及铸件的上部或冒口处。如果缩孔深及锭身,由于它象根管子故习惯上称为缩管。在钢锭里有时还会产生二次缩管(即二次缩孔)。当钢锭开坯时切头量不足,缩管 Shrinkage is a macro-defects often found in large castings and forgings, usually in the upper part of the ingot and casting or riser. If the shrinkage hole deep and the body, it is customary because of its root canal shrink tube. Sometimes in the ingot will produce secondary shrink tube (ie secondary shrinkage). When the ingot billet when the lack of cut, shrink tube