汽车发动机的缸体、缸盖、进排气管及某些通气、通水的铸件,由于诸多因素的影响,在铸造过程中容易产生砂眼、气孔、局部组织疏松等缺陷,致使大批零件报废。多年来,为了解决这个问题,一方面努力提高铸造技术,采用先进的铸造工艺,另一方面采用镶套、压套等方法,在一定程度上可修复一些零件,减少铸件废品率。但这些方法 Due to the influence of many factors, the cylinder body, cylinder head, intake and exhaust pipes, and some castings of ventilation and water are prone to produce defects such as trachoma, porosity and local loose structure in the casting process, resulting in the scrap of a large number of parts. Over the years, in order to solve this problem, on the one hand efforts to improve the casting technology, the use of advanced casting technology, on the other hand using the set, pressure sleeve and other methods, to some extent, can repair some parts, reduce casting reject rate. But these methods