为生产高质量、高性能要求的不锈钢活塞顶,对其化学成分、铸造工艺及热处理工艺进行了优化分析,结合酯硬化水玻璃砂工艺出现的缺陷问题提出了防止措施,为批量生产合格铸件奠定了基础.实际生产经验表明,气孔是生产过程中的主要缺陷,通过减少发气源、增强排气及控制浇注工艺等措施取得了较好效果;在ZG20Cr13基础上添加Ni、Mo合金元素,并采用95 0℃保温2～3h油淬、65 0℃保温2～3h回火的调质处理工艺,满足了零件的性能要求.

The 240 en-block piston rings were produced by self-designed shell core in practical plant conditions,and the microstructure and properties of the piston rings were compare with that produced by green-sand.The results show that the technical parameters of the piston rings produced by shell core process can meet the technical criterion of the piston ring completely.The hardness of the piston rings produced by the two processes is almost equivalent,while the complex properties of the piston rings produced by shell core process are better in metallurgical microstructure,bending strength and abrasion resistance etc.

The housing castings produced with former casting method had defect revealed by magnetic traces congregation which were analyzed with numeral simulation software and concluded that the defects were the oxide inclusion caused due to the turbulence and splash of the mold-filling iron melt stream and the oxide dross which was formed in the later mold-filling period and then floated to the surface layer and congregated.At last,by adopting bottom gating system,keeping the ingates from striking the mold and core,ensuring enough filling space in the front of filling stream,setting filter before the ingates,and setting nodular iron-special exothermic risers on the hot spots etc.,the secondary oxide dross inclusion was effectively eliminated and the shrinkage defect was also prevented and so that the process yield was increased.

采用模拟软件Magma对铝合金轴箱前盖铸造工艺方案的充型及凝固进行模拟,分析对比了2种方案各自的优缺点。综合考虑,确定采用水平压边胃口顶注方式,并在此基础上采取保温砂套、局部冷却水管激冷等改进工艺,实现了冒口的圆满补缩,铸件获得了良好内部质量。同时在压边冒口下方增设内浇道以及使用过滤片,确保了铸件外观质量。

动车组铝合金电机端盖采用金属型重力浇铸成型,树脂砂造芯铸造工艺。通过在型腔上开设排气,解决了铸件浇不足等缺陷,合理地利用型腔内的气体,解决了铸件局部缩凹缺陷,最终开发出质量良好的铸件。