The results of studies on the use of magnesium alloy in modern Tundish for production of vermicular graphite cast irons were described. This paper describes the results of using a low-magnesium ferrosilicon alloy for the production of vermicular graphite cast irons. The paper presents a vermicular (and nodular) graphite in different walled castings. The results of trials have shown that the magnesium Tundish process can produce high quality vermicular graphite irons under the specific industrial conditions of Foundries - Odlewnie Polskie S.A. in Starachowice. In this work describes too preliminary studies on the oxygen state in cast iron and their effect on graphite crystallization.
The paper presents the results of studies of the effect of chromium concentration on the solidification process, microstructure and selected properties of cast iron with vermicular graphite. The vermicular graphite cast iron was obtained by an Inmold process. Studies covered the cast iron containing chromium in a concentration at which graphite is still able to preserve its vermicular form. The effect of chromium on the temperature of eutectic crystallization and on the temperature of the start and end of austenite transformation was discussed. The conditions under which, at a predetermined chromium concentration, the vermicular graphite cast iron of a pearlitic matrix is obtained were presented, and the limit concentration of chromium was calculated starting from which partial solidification of the cast iron in a metastable system takes place. The effect of chromium on the hardness of cast iron, microhardness of individual phases and surface fraction of carbides was disclosed.
The results of studies on the use of magnesium alloy in modern Tundish + Cored Wire injection method for production of vermicular graphite cast irons were described. The injection of Mg Cored Wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire for the production of vermicular graphite cast irons at the; Tundish + Cored Wire to be injected methods (PE) for pearlitic-ferritic matrix GJV with about 25 %ferrite content. The results of calculations and experiments have indicated the length of the Cored Wire to be injected basing on the initial sulfur content and weight of the treated melt. The paper presents a microstructure matrix and vermicular graphite in standard sample and different walled castings. The results of numerous trials have shown that the magnesium Tundish + PE Method process can produce high quality vermicular graphite irons under the specific industrial conditions of the above mentioned foundries.
Reason for and risks of using of cast iron with vermicular graphite for typical construction parts. Ultrasound checking of graphite shape. Factors influencing plausibility of result. Difference between laboratory and operation application. Roughness, parallelism, stabilityand size dimension of walls. Conditions, proposals for simplification and productivity enhancement of castings checking. Recommendation.
The paper deals with possibility to improve operating performance of cast-iron heat exchangers by providing them with a copper alloy (CuTi2Cr) with the use of the flame spraying method. A test exchanger was cast of a gray cast iron with vermicular graphite in ferriticpearlitic matrix obtained in production conditions at KAW-MET Iron Foundry with the wire method used to vermicularize the material. The test samples were two plates cast in sand molds, of which one was given a flame-sprayed CuTi2Cr coat on one side. The operating performance of such model cast-iron heat exchangers, with and without CuTi2Cr coating, was tested on a set-up for determining the heat flow rate (thermal power) transferred by the heat exchanger to environment. The obtained results indicate that the value of the heat flow rate characterizing the CuTi2Cr-coated cast-iron heat exchanger was by 10% higher compared to the flow rate of heat conveyed to environment by the heat exchanger without coating.