| Popis: |
Ductile iron is currently one of the most popular construction materials. Its mechanical properties are close to those of steel. The basic material in the production of ductile iron is gray iron, which can be produced in a cupola or in an electric induction or electric arc furnace. After tapping the gray cast iron from the furnace, the gray cast iron is processing into ductile iron. This process is called modification. Magnesium and its alloys and cerium are most often used as modifiers. In addition to the modification, the cast iron must then be inoculated. This paper deals with the impact of gray cast iron modification on the working environment. The experiments were performed in two foundries, where three modification technologies were used: the pouring method, the Tundisch cover and the Flottret method. The aim of the experiments was to determine how the individual modification methods affect the development of magnesium vapor, the content of carbon monoxide in the working environment and the temperature in the working environment. During the experiments, the CO content and temperature were measured before the modification itself, immediately after the modification and one hour after the modification. The greatest development of CO occurred after the modification. This was most significant in the pouring method. A similar situation occurred in the case of a change in temperature. Within one hour of the start of the modification, both the CO content and the ambient temperature returned to the original level before the modification. |
