湿型砂性能影响因素研究

Study of Influencing Factors on Properties of Wet Sand

湿型粘土砂造型工艺作为铸造生产的重要组成部分,对生产质量具有举足轻重的作用。通过含水量、碾砂时间、死粘土、添加剂和膨润土变化对型砂性能的影响进行试验研究。结果显示:含水量超过膨润土吸水能力后,随着加水量增加,型砂强度和透气性降低、紧实率提升;在一定时间范围内,随着碾砂时间延长,强度、透气性和紧实率增加,105℃可检测水分成降低趋势;在过多含水量情况下,加入适量死粘土可提升强度,但过多的死粘土会导致强度降低;型砂中加入煤粉类添加剂会降低紧实率和热湿拉强度;膨润土中蒙脱石含量会影响所制备型砂性能。

As an important part of casting production,wet clay sand molding process plays an important role in production quality.The effects of water content,grinding time,dead clay,additives and bentonite on the properties of molding sand were studied.The results showed that when water content exceeded the water absorption capacity of bentonite,the strength and permeability of molding sand decreased and the compacting rate increased with the increase of water added.In a certain time range,with the extension of grinding time,the strength,air permeability and compacting rate increase,and the moisture formation can be detected at 105℃.In the case of excessive water content,adding proper amount of dead clay can improve the strength,but too much dead clay will cause the strength to decrease;Adding pulverized coal additives to molding sand can reduce compaction rate and hot wet tensile strength.The content of montmorillonite in bentonite will affect the properties of molded sand.