Papers by Keyword: Induction Furnace

Abstract: The objective of this study is to investigate the effect of adding some alloying elements (including iron, aluminum, chromium, cobalt, and titanium) to 90 wt. % copper – 10 wt. % nickel alloy on the hardness property. Copper-nickel synthetic alloys were prepared in an induction furnace, in an argon/7% vol. hydrogen atmosphere in cylindrical boron nitride crucibles. They were then homogenized at 950°C for 10 hours in the same protective atmosphere. Vickers hardness measurements, microstructure examination, and Energy Dispersive Spectrometry (EDS) mapping analysis were performed for all synthetic alloys. Hardness measurements results show that the addition of all the alloying elements used in this investigation improve the hardness of the 90 wt. % copper – 10 wt. % nickel alloy. It was concluded that the aluminum was the most effective alloying element on the hardness value for 90 wt. % copper – 10 wt.% nickel alloy.

Abstract: This study contains results of carbonaceous SHS-refractory materials application for binding of the graphite products and melting of metals in the induction furnaces. The opportunity of producing strong graphite-graphite bond up to 5 MPa by means of the carbonaceous refractory material that demonstrated high chemical stability in the aggressive liquid metals and alloys environment has been shown. The results of the industrial tests of melting crucibles made of carbonaceous SHS-refractory materials have been presented in the case of aluminium melting. It has been shown that such crucibles stability is 5-6 times higher than that of standard graphite crucibles in aluminium melting conditions. The obtained research results testify that developed carbonaceous material is applied for lining of the induction furnace of melting unit is allow to increase the number of nonferrous metals (bronze) melting cycles from 5 to 6 times in comparison with the traditional graphite crucible melting. High chemical stability of the material to oxidizing environment as well as to metal melts is provided by formation of high-melting compounds in the carbonaceous exothermic systems during SHS-process.

Abstract: Stainless steelmaking dust contains significant levels of Cr-bearing phases (typically 0.28~16.5%). In this study, stainless steel was produced in an induction furnace, dust generated during the smelting process is collected in order to classify dust formation mechanisms and effects of operation parameters of smelting process on the formation of Cr(VI) species in the dust. The results showed that approximately 60% of dust generated during stainless steelmaking process by induction furnace is due to entrainment of charge fines, about 30% of dust formed due to metal and slag splashing result in oxygen and argon injection, and only about 10% of dust are formed through vaporization from the melt bath. In addition, the Cr-bearing phases in the dust mainly generate due to slag and metal splash. It can increase Cr(VI) content in the dust by increasing the chromium content in the molten steel, the amount of slag former and temperature of molten. To accelerate the cooling rate during the sampling period will decrease the Cr(VI) content in the dust.

Abstract: The medium frequency induction furnace power control system of industrial grade includes the microcontroller STC89C52RC, power converters, data amplifiers, analog to digital converter, stepper motor and excitation regulator, etc. The medium frequency generator’s output voltage and current signals are passed to the power converter to transform the millivolt DC signal into a linear relationship. The outputs from the power amplifier controlled by the data conversion single-chip are input through the ADC. The signals are compared with the power base value set by the user to calculate the control commands, to control the stepper motor action and control the stepper motor to forward or reverse, as well as to adjust the excitation current. Therefore, the medium frequency generator output power is stable. The heating temperature of the work pieces are precise controlled. A detailed description of the system's hardware and software composition and design methods are illustrated in this paper.