Development Of A New Cast-Steel Riser Covering Flux

In the casting process of cast steel parts, the quality of casting steel can be improved by using a cast steel riser covering flux, because the flux can delay the solidification time of molten steel in the riser,and enhance the feeding capacity of the molten steel in the riser to the casting. However, with the development of casting technology and more higher requirement for the quality of casting steel,conventional cast steel riser covering flux couldn't fit for increasingly requirement of cast steel production. Therefore,it has important significance to develop a new kind of cast steel riser covering flux.In this paper, the condition of the covering flux on molten steel was simulated by a high-temperature box-electric heater, at the same time, a time-temperature curve was obtained with a multi-channel data collector. Firstly, the effects of components on heat-insulation and heating were researched by single factor testing method. The results show that, when the content of expanded graphite was 8-18wt%, perlite was 12-20wt% and euthermic agent was 10wt%, the property of dilatability, euthermic and heat-insulating was great, the cost of covering flux was reasonable. Secondly, the components of new covering flux were optimized by orthogonal experiment. With the results that, the best components were Al 4-8wt%, fuel ash 25-35wt%, perlite 15-18wt%, acidification graphite 14-18wt%, carbon powders 10-15wt%, trigger agent 2-3wt%, others 18-22wt%.Finally, production test further proves that the developed cast steel riser covering flux has both euthermic and heat preservation effects. The flux can improve the feeding capabilities of risers obviously, and reduce efficient height of risers, save molten steel, and improve qualities and producing rate of castings. Therefore, the developed cast steel riser covering flux is an effective cover flux.