铸钢件产品阀门的三大件:阀体、阀盖和闸板的铸造工艺设计大都采用普通暗冒口和冷铁等措施来获得致密的阀门铸件。工艺出品率一直比较低,在50％左右,而且缩松和砂眼时有发生,有时还比较严重。通过对阀盖铸件冒口设计的改进,在保证铸件质量和产品使用性能的前提下,工艺出品率有了明显的提高。 原阀盖铸造工艺见图1,一箱四件布置,两法兰相对,中间设置φ130mm×190mm普通暗冒口,阀盖小头设置φ85mm×130mm暗冒口。这一设置不仅工艺出品率低,只有53％,而且造型操作时冒口顶部容易露背砂,在CO_2硬化、表面烘干及浇注过程 Steel Castings Three big pieces of the valve: the valve body, valve cover and gate of the casting process design mostly used ordinary dark riser and cold iron and other measures to obtain a dense valve castings. Craft production rate has been relatively low, about 50%, and shrinkage and trachoma have occurred, and sometimes more serious. Through the improvement on the design of the riser of bonnet casting, the yield of technology has been obviously improved under the premise of guaranteeing the casting quality and the product performance. The original valve cover casting process shown in Figure 1, a box of four layout, the two flanges relative, the middle set φ130mm × 190mm common dark riser, small head cover set φ85mm × 130mm dark riser. This setting is not only a low yield of technology, only 53%, and the top of the riser when modeling operation easy to reveal the back sand, CO_2 harden, surface drying and pouring process