Gas Atmosphere Formed in Casting by Full Mold Process

Archives of Metallurgy and Materials

A. Chojecki¹  J. Mocek¹ 

[1] AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY, FACULTY OF METALS ENGINEERING AND INDUSTRIAL COMPUTER SCIENCE, AL. A. MICKIEWICZA 30, 30-059 KRAKÓW, POLAND

关键词: Keywords: bentonite;    thermostability;    DTA/TG analysis;    XRFS analysis;    mechanical properties;    bentonite soda – activation;   

DOI  :  10.2478/amm-2014-0176

学科分类：金属与冶金

来源: Akademia Gorniczo-Hutnicza im. Stanislawa Staszica / University of Mining and Metallurgy

【 摘 要 】

A test mold was designed to investigate the full mold process. Pressure changes in a gap developing between the pattern made of foamed polystyrene and the raising column of liquid alloy were determined. Studies were conducted pouring molds with cast iron and with AK11 silumin. It was found that pressure is significantly higher in the case of cast iron, due to a higher rate of pattern decomposition and more advanced dissociation of hydrocarbons. The increase in pressure was observed to have no significant effect on changes in the pouring rate as it was compensated by higher metallostatic pressure. The increase of pressure occurs immediately after the start of pouring, it reaches a maximum and then stabilizes or decreases smoothly as a result of the drop in metallostatic pressure. The temperature of pouring has a significant effect on the decomposition rate of hydrocarbons evolving from the metal. During pouring of cast iron, the presence of hydrogen was revealed. It was particularly evident across the gas-permeable coating, where the concentration has exceeded 40%. Hydrogen precipitation was accompanied by an evolution on the casting surface of considerable amounts of pyrolytic carbon. It was found that gases forming in the gap were totally free from oxygen.

【 授权许可】

Unknown