Abstract: This paper presents a method for calculating the life of steam turbine. The critical damage curve is introduced in this paper, which causes by the action of cumulative of low cycle fatigue and creep rupture. The curve is modified by giving a equation of the curve and depicting the curve. In steam turbine opration local, authors propose that the component hardness variation must be consider in calculating the life, and the equation must involve the hardness variation.

Key words: 低周疲劳损耗, 金属蠕变, 汽轮机转子