This paper deals with the creep strain generated during PWHT by both experimental data of inherent strain and numerical results of that. The experiment of inherent strain was done by using Cr-Mo steel and SHT490 steel. The initial yielding stress and 0.2% proof stress were measured at high temperature. The main conclusions obtained were as the following:
(1) the creep strain of PWHT is generated during the heating process.
(2) the creep strain of PWHT is estimated by the strain hardening.
(3) the creep strains of Cr-Mo steel and SHT590 steel can be estimated by the equation with the stress index and the strain index being not depend on the kind of steel, but only one creep constant changing by the kind of steel.
