THERMAL STRESSES GENERATED IN THE LINING OF A STEEL LADLE
A. S. Nikiforov
and E. V. Prikhod’ko
Translated from Novye Ogneupory, No. 10, pp. 84 – 87, August, 2005.
Original article submitted May 20, 2005.
Conditions for the thermal regime of 25-ton steel ladles lined with periclase-carbon refractories are analyzed.
The input data for numerical analysis are the temperatures at the inner surface of the lining measured experi
mentally. Temperature profiles over the cross-section of the hot layer of the lining are calculated and then used
to determine thermal stresses in the refractory material. A conclusion is drawn that sharp temperature gradi
ents during the heating-up should be avoided. The currently employed heating regimes generate thermal
stresses that exceed the strength tolerance limits for refractory materials.
Heating-up of the refractory lining is a critical operation
for any metallurgical plant as it is being put in service. The
rapid heat-up of the lining is favorably looked upon by tech-
nologists since it allows one to save fuel and reduce the
standby time to a minimum. On the other hand, the heat-up
rate cannot be too high at the risk of excessive thermal
stresses that may generate cracking and spalling of the re-
fractory material and thus to shorten the campaign of the
To study thermal stresses generated by heating we con
sider the lining of a 25-ton steel ladle. The lining in question
was composed of five layers. The thickness of the operating
layer (hot layer) made of a periclase-carbon refractory was
135 mm, and that of the reinforcing layer (chamotte) was
65 mm. Sandwiched between these two layers is a rammed
mullite-corundum mixed layer 30 mm thick. The graded lin
ing was insulated from the metal casing by sheets of asbestos
cardboard 10 mm thick. In what follows, an analysis of ther
mal stresses will be given only for the hot layer of the graded
The input data for numerical analysis were temperatures
at the inner surface of the lining that were measured experi
mentally. The temperature at the inner surface of the lining
varying over time is shown in Fig. 1.
For solving the problem of inner heat exchange within
the hot layer, some simplifying assumptions were made. We
assume that the hot layer is uniform and isotropic, with con-
stant values of the specific heat capacity per unit volume c
× K)] and heat conductivity l [W/(m × K]. The mathe-
matical formulation of the problem is
0<y < H, (1)
where a is the thermal diffusivity, m
The temperature of the inner surface of the lining being
known, the boundary condition of the 1st kind is written as
Refractories and Industrial Ceramics Vol. 46, No. 5, 2005
1083-4877/05/4605-0360 © 2005 Springer Science+Business Media, Inc.
Pavlodar State University, Pavlodar, Republic of Kazakhstan.
0 2 4 6 8 10121416182022
Fig. 1. Temperature at the internal surface of the lining plotted as a
function of time.