EFFECT OF COLD-ROLLING ON CREEP-BEHAVIOR OF A 10CR-30MN AUSTENITIC STEEL

The effect of cold-rolling on creep deformation has been investigated for 10Cr-30Mn austenitic steels containing 0.003, O.11 and 0.55 mass% carbon. After 20% cold-rolling at room temperature, the specimens were subjected to creep test; at 873K for up to about 10000h. The test res ults were compared with those of solution-annealed specimens. The cold -rolling caused a decrease in minimum creep rate epsilon(min) and an i ncrease in time to rupture t(r) at high stresses and short times. At l ow stresses and long times, however, the effect of cold-rolling on the epsilon(min) and t(r) depended on carbon concentration and test durat ion. The t(r) of the specimens was described by t(r) = 1.45/(epsilon(m in).Omega(p)), where Omega(p) is the creep damage parameter given by O mega(p) = dln epsilon/d epsilon. Both the epsilon(min) and Omega(p) ar e correlated with the microstructural evolution during creep, such as the precipitation of sigma phase, M(23)C(6) and the recrystallization of deformed grains produced by cold-rolling.