An analysis of the service of high-alumina plates of ladle slide gates

Abstract

The generally known advantages of slide equipment over stoppers in teeming steel from ladles [i, 2] has been responsible for the broad introduction of stopper-free teeming of steel in the USSR and abroad.At present about 80% of the steel melted in the USSR is teemed from ladles equipped with slide gates both in top and bottom pouring into molds and in pouring into pony ladles.Periclase and high-alumina compositions have found the widest use in the USSR as materials for production of slide-gate plates [1][2][3]. High-alumina plates are well recommended in top pouring of carbon and alloy steels into molds accompanied by an increased number of openings and closings [4,5]. An analysis of certificate data of 299 lots of plates made it possible to establish the high stability of the AI203 (95.5-96.8%%) and Fe203 (0.6-0.7%) contents in them. At the same time, significant variations in open porosity Popen (7.5-14%) and compressive strength Ocomp (120-250 N/mm2)% related to it were noted. An analysis of the results of teeming of metal showed that the number of disturbances in teeming (emergency opening of the gate, passage of metal between the plates, leakage of it into the steel teeming channel) is related not only to wear of the plates but also to a significant degree to disturbances of a technical and organizational character such as a reduction in metal temperature, failures of equipment, and poor assembly and installation of the slide gates and their elements. Therefore, for a further analysis, only disturbances of the method of pouring related directly to wear of the sliding surfaces of the plates, *A. P. Presnyakov, G. S. Mit'kova, Z. Ya. Pavlenko, T. P. Kolpashnikova, and G. A. Kopylov participated in the work. there and subsequently, wt. % is given. $Technical Specification 14-8-213-75 in effect in the period considered specified AI203 of 95% min, Fe203 of 0.8% max, Popen of 14% max, and Ocomp of 120 N/mm 2 min. All-Union