METHOD OF MANUFACTURING TAPE FROM LOW-ALLOYED HEAT-RESISTANT STEEL Russian patent published in 1997 - IPC

FIELD: metal working. SUBSTANCE: invention concerns working of metals under pressure and can be utilized in rolling production, in particular, when manufacturing tape for spiral silvering of pipes at power plants. Method includes double-conversion cold rolling of hot- rolled plate-strips with intermediate and ultimate heat treatments. Novelty resides in that the first cold conversion is conducted with relative deformation degree 40-60% and heat treatments are carried out, respectively, in three and two steps. In the first step of intermediate heat treatment, plate-tape is maintained at 500-550 C for 4.5-5.0 h, in the second step at 800-820 C for 16-17 h, and in the third step, plate-tape is maintained in presence of water vapor with dew-point temperature 10-20 C. In the first step of ultimate heat treatment, tape is kept at 500-550 C for 2.5-3.0 h, and, after the second step, rolled tape is heated to 600-650 C with rate at least 3 C/min. EFFECT: enhanced efficiency of process. 4 cl, 4 tbl