D155缸体铁豆缺陷问题的解决措施

Measures to Solve Cold Shot Metal Problem of D155 Cylinder Block

介绍了D155缸体的生产工艺及生产过程中铸件存在的铁豆缺陷,对可能造成这种缺陷的原因进行逐一排查。在严格控制浇注操作和浇注温度后,铁豆废品率仍然较高的情况下,采取了如下工艺改进措施:在砂芯对应易产生铁豆的部位增设一个承接铁豆的凹坑,凹坑尺寸为50 mm×30 mm×15 mm,与铸件相连接部位的深度为5 mm;在容易进铁液的通气孔正下方的芯头部位再增设1个凹坑,用来承接从通气孔倒灌入芯头的铁液,避免其通过上型与砂芯间的间隙进入型腔,减少提前进入型腔的铁液。生产结果显示:D155缸体铁豆废品率从1.563%降低到0.065%,效果显著。

The casting production process of D155 model cylinder block and cold shot metal defect existing in its production process was introduced. The reasons could cause this defect were investigated and analyzed one by one. Ureter the condition that after the pouring temperature and pouring operation having been strictly controlled,the cold shot rejection rate was still quite high,the following method improvements were adopted：setting a small concave pit on the cores to collect the shot metal,the dimensions of the pit was of 50 min×30 mm×15 mm and the depth of the pit neck to connected with the casting was of 5mm. Besides,setting another pit in the location of the core print directly under the venting hole that the mohen metal was easy to enter into,to collect the molten metal entering into the core print from the venting hole and thereby to prevent the molten metal to enter the mold cavity through the gaps between cope and the core,to reduce amount of molten metal entering in advance into mold cavity. Tbe production result showed that the cold shot rejection rate of the D155 block was decreased from 1.563% to 0.065%. The effect was obvious.