An analysis of thermal processes in the heating furnace for treating continuous cast bars before tube production is presented. In accordance with the proposed scheme modernizing construction of the furnace floor, calculations of the temperature dynamics and uniformity in concast bars are performed. Advantages and disadvantages of this scheme are noted. For radiative heat transfer the modified zonal method has been used. The main features of the method are high accuracy and reduction of the calculation time by ten and hundreds of times. © 2017 Begell House Inc.. All rights reserved.