Papers by Keyword: Casting Powder

Abstract: The article deals with analysis of defects indicated in large forgings in the course of ultrasonic testing. The aim of the metallographic analysis of the defects was to establish whether and to what extent casting or filling powders took part in their emergence that had been used when casting the ingots from which the forgings were made.

Abstract: This paper proposed the measuring device for the casting powder crystallization and the crystalline proportion test by the double thermocouple. The two different dual platinum-rhodium thermocouple wires are acted as heating element and temperature measurer at the same time, so that, the temperature of both wires apart can be controlled accurately. Adjusting the two wires distance discretionarily, the crystalline state can be observed under the different range of temperature of flux film on the both sides. The fast temperature raising and high efficiency of metering technology is designed for the measurement device and achieved great sense to research the casting powder characters in the crystallizer.

Abstract: The basic idea of the work was to analyze the effect of the wollastonite mineral CaO SiO2 content in the continuous casting powder related to the SEN erosion. In order to realize the research, experiments were conducted in the laboratory conditions. The research, experiment, was realized in the Magnohrom Kraljevo laboratory, and cryptonym furnace EV16 was used for refractory material behavior. Cut SEN pieces from the slag zone in the reduction atmosphere were treated in the furnace with three types of casting powder of different mixtures ratio of SRD1 (without wollastonite) and SRD2 (with wollastonite): Casting powder 1 - SRD1/SRD2 = 50/50 %, Casting powder 2 - SRD1/SRD2 = 25/75 % and Casting powder 3 - SRD1/SRD2 = 75/25 %. Temperature of the experiment was in the range of 15200C – 15400C, and treatment time was changed simulating the average casting time of the heat; one heat (45 min), two heats (90 min), and three heats (135 min). The experiment pointed out that the erosion of the SEN was reduced with the increased ratio of wollastonite in the casting powder. The erosion rate of the SEN exposed to the casting powder 2 in the laboratory conditions was 0.0055 mm/min, whilst the erosion rate of the SEN exposed to the casting powder 3 (with the least wollastonite content) was 0.0075 mm/min. Erosion rate of SEN exposed to the casting powder 2 was lower for the 26.27 % related to the casting powder 3, and 17.90% lower than the erosion rate of the casting powder 1 (the erosion rate of the casting powder 1 was 0.0067 mm/min). These laboratory experiments are very consistent with results obtained in the plant conditions [1,2,3]. At that time, results indicated that SRD1 casting powder without wollastonite has the erosion rate 46 % higher than SRD2 casting powder with wollastonite. On the basis of the laboratory researches and earlier plant conditions researches it could be concluded that wollastonite mineral content in the casting powders has significant effect on the SEN erosion, in the way that the SEN erosion rate was decreased with the increased wollastonite content in the casting powders.