涂料的烧结性及防气孔效果的研究

An Investigation on the Effect of Sintering Character of Foundry Coating on the Prevention of Subsurface Pinhole Defect in Steel Castings

含氮树脂砂易引起低碳钢铸件产生皮下气孔,为防止气孔的产生,本文对几种烧结型防气孔涂料及其效果进行了实验研究,结果表明,好的涂料配方具有理想的烧结性,因而具有屏蔽砂芯(型)气体的好效果.文中根据扫描电镜(SEM)观察和电子探针微区分析(EPMA)结果,提出了烧结型涂料的防气孔机制.

It is generally known that use of nitrogen-containing resin-bonded sand is apt to lead to subsurface pinhole defects in low-carbon steel castings. The composition of sintering coatings and its effect on preventing such defects have been experimentally investigated. The results show that the bauxite coating provides excellent sintering character and is found to be capable of shielding the casting from core gas. The mechanism is also studied by SEM and EPMA. It is concluded that bauxite coating is useful to steel casting production if nitrogen- containing resin-bonded sand is to be used.