Abstract: Steam turbine can remain a safe production state for a long period under the environment
of high temperature and high pressure if it has certain good strength and intensity. The methods of
Wahl, M-V and finite element analysis were used in analysis of intensity for a subcritical state turbine
diaphragm. The results showed that the maximum stress of the diaphragm appeared at the blade’s
enter side of the blade root, the maximum strain appeared at the equatorial plane at an inner diameter
of the inner ring, and the maximum stress of the board appeared at the inner diameter of the inner ring
which was vertical to the equatorial plane. The errors of finite element method and Wahl method were
smaller, so it proved the reliability of finite elements analysis.

Key words: turbine diaphragm, finite elements analysis, Wahl method, intensity analysis