Determining the thermally-stressed state of motor-driven bowls for transporting liquid slag

Abstract

Slag bowls were chosen as the object of research, as important components of blast furnace, steelmaking, and ferroal-loy shops of metallurgical enterprises. The main problem of operation of any slag trucks is their limited durability and fre-quent destruction of slag bowls. The reason for these problems is changes in the shape of the bowls during operation, manifested in the formation of narrowing places in the area of the support ring – for rail-mount-ed bowls, destruction of supporting pins – for rail-mounted slag trucks, or cracks in the walls. Those defects appear as a result of cyclic thermal effects of liquid slag on the bowl. Based on the results of computer simulation, it was established that the main role in the destruction of the support pins of motor-driven slag bowls belongs to temperature changes. The temperature stresses arising in the bowl are localized in the area of the slag mirror (200–250MPa for 25L steel, 280–350MPa for 30HML steel). The results provide grounds for improving the pre-sented slag bowl to reduce temperature stresses in its walls and structures of the supporting trunnions. The results report-ed here are explained by the fact that with uneven heating of elastic bodies, tempera-ture stresses appear, which, under certain configurations of temperature loads, lead to the destruction of structures. The find-ings from these studies are recommended to be used at enterprises for the design and manufacture of slag bowls, as information on the localization of dangerous places of the structure. In addition, the data pre-sented here could be useful for metallurgi-cal enterprises for detailed technical diag-nosis of bowls in their dangerous places.