我厂产品中,盖子等类型的小型铜铸件很多,在以往生产中,次品与废品率大,常因补制工作打乱生产计划,影响生产任务的顺利完成,次废品主要是表面粗糙、缩孔、缩松,而技术要求很高的防爆件,稍有缩松现象,也得报废.自从采用硬型铸造以后不但保证了质量得到组织致密具有较高的机械性能的铸件,同时还有下述几个优点:(1)用硬型铸造,不必造型,作一小部 I plant products, covers and other types of small pieces of copper castings in the past, in the past, the rate of defective products and rejects, often due to make up the work to disrupt the production plan, affecting the successful completion of production tasks, secondary wastes mainly rough surface, Shrinkage, shrinkage, and high technical requirements of the explosion-proof parts, a slight shrinkage phenomenon, have to scrap. Since the use of hard casting not only to ensure the quality of the organization obtained by the organization of dense high mechanical properties of castings, as well as The following advantages: (1) with hard casting, no modeling, make a small