摘要
传统煤粉潮模砂铸造生产,由于煤粉的添加,能够改善铸件表面质量和有效防止粘砂。但是,煤粉在高温下会产生多种有毒有害的气体和固体物质,一方面对环境产生污染,损害工人健康;另一方面其中的含硫气体物质渗入铁液,极有可能影响球铁铸件球化。本文以球墨铸铁件为研究对象,研究了煤粉湿型砂铸造生产的梯形球墨铸铁件的微观组织。研究结果表明,煤粉潮模砂铸造的球墨铸铁件总体上石墨分布较稀疏,在最表层几乎看不到球墨的存在;随着铸件壁厚的减小,珠光体级别越来越高。其原因是煤粉在高温下分解产生的含硫物质渗入到铸件表层降低了球化元素的作用,随着铸件壁厚减小冷却速度加快会促使珠光体的生成。
The quality of castings can be improved and burning-on can be effectively prevented due to the addition of pulverized coal in green sand.However,sulfur-containing substance and other toxic and harmful gases will be produced by pulverized coal at high temperature.On the one hand,it will pollute the environment and damage the health of workers.On the other hand,sulfur-containing substance can infiltrate into molten iron and affect the modularization of nodular iron castings.The results show that the graphite distribution of ductile iron casting by green sand is sparse,and the existence of nodular graphite can hardly be seen in the surface layer.With the decrease of casting wall thickness,the pearlite grade becomes higher and higher.The reason is that the sulfur substance produced by the decomposition of pulverized coal at high temperature infiltrates into the surface of the casting,which reduces the effect of spheroidizing elements.With the decrease of the wall thickness of the casting,the cooling rate is accelerated,which is conducive to the formation of pearlite.
作者
刘树江
宋刚
丁迎生
杨忠诚
聂卓越
顾云会
朱世根
LIU Shu-jiang;SONG Gang;DING Yan-sheng;YANG Zhong-cheng;NIE Zhuo-yue;GU Yun-hui;ZHU Shi-gen(Dehualong(Tianjin)Power Transmission Machinery Industry Trade Co.,Ltd.,Tianjin 300202,China;Tianjin Zhenghe Metal Products Co.,Ltd.,Tianjin 301609,China;Donghua University,Shanghai 200051,China)
出处
《铸造设备与工艺》
2021年第2期26-30,共5页
Foundry Equipment & Technology
关键词
煤粉湿型砂
梯形试块
微观组织
nodular iron
pulverized coal
green sand
ladder-shaped
microstructure
