Effect of Pre-deformation on Properties of SUPER304H Tube

The heat-resistant steel tube SUPER304H used for ultra-supercritical (USC) boiler was pre-performed with deformations of 0,15% and 20%, and then to aged at 700 ℃ for 100, 1 000, 5 000 h. The effets of pre-deformation on properties of the tubes before and after aging were studied. The results show that room temperature strength, hardness and short-term high temperature strength of the deformed tubes increased with the increase of pre-deformation, but the plasticity reduced sharply with a certain value retained. The hardness changes of aged tubes mainly depended on pre-deformation instead of aging time, however, its short-term high temperature strength was deceased by aging treatment. The pre-deformation less than 20% had limited affect on the SUPER304H tubes′ creep rupture properties.