铸造过程中渣粒运动轨迹及夹渣位置研究  

Study on Slag Particles Moving Trail and Slag Inclusion Position in Casting Process

作　　者：饶磊[1,2] 胡启耀[2] 朱炼兵[2] 

机构地区：[1]河海大学机电工程学院,江苏常州213022 [2]南昌大学机电工程学院,江西南昌330031

出　　处：《铸造》2012年第12期1433-1438,共6页Foundry

基　　金：国家自然科学基金项目(51165030)

摘　　要：铸件中的夹渣缺陷破坏了材料的连续性,易形成局部应力集中和疲劳裂纹扩展源,严重地影响了铸件的服役性能。由于渣粒数量众多,运动轨迹复杂,对其运动轨迹及停留位置预测较困难。本文通过铝合金应力框铸件的浇注试验,基于分散相粒子模型进行了充型和凝固过程中渣粒运动轨迹跟踪,分析了等直径二氧化硅渣粒在铸件和浇注系统各个关键位置的运动特征,获得了充型和凝固过程中金属液的流动规律、温度变化特点对渣粒运动轨迹及最终停留位置的影响规律。结果表明,金属液在充型过程中的局部流场特点和充型路径对夹渣缺陷的分布有较大的影响,型腔中产生涡旋流场处和流量较大的区域均易出现夹渣缺陷。同时验证了冒口具有明显的局部集渣作用,合理的开设和布置冒口能有效地降低铸件夹渣率。采用分散相粒子模型能有效地预测铸造过程中夹渣粒子的运动轨迹,为提高铸件质量提供参考。Slag inclusion defects break continuity of casting material, so stress concentration and fatigue crack propagation source easily occurred in these positions and slag inclusion defects lower the service property of castings seriously. Because slag particles have large quantity and complex moving trail, predicting the moving trail and finial position is difficult. In this paper, aluminum alloy stress box casting has been poured and particle movements tracing in pouring and solidification process has been done by dispersed phase model. The uniform diameter SiO2 particles movement characteristic at key positions of casting and gating system has been analyzed. Particles moving trail feature and finial location distribution rules have been gotten, which influenced by melt flow rule and temperature changing characteristic in casting process. The results show that local flow field and filling path have important influence on slag inclusion defects distribution in casting. The positions with vortex flow field or high flow rate are always slag inclusion defects generating zone. Meanwhile, riser has significant slag trap function, which can lower slag inclusion rate in casting by reasonable riser location. Slag particle moving trail in casting process can be predicted by dispersed phase model, which provides helpful references for improving casting quality.

关 键 词：渣粒 运动轨迹 夹渣 位置 

分 类 号：TG245[金属学及工艺—铸造]