Study on the Heat Indication Test of Turbine Rotor Forgings

Abstract

A lot of problems concerning the heat indication test were settled by the use of a model apparatus of heat indication test and by the application of some advanced techniques of metallurgical experiments. Main points are as follows. (1) Proposal of type C' deflection. (2) Two kinds of type C deflection which are caused by the non-uniform distribution of Mo dissolved in matrix could be eliminated only by heat treatments. (3) Types A, D and C' of deflection which are considered attributable to the non-uniform thermal emissivity of forging surface could be completely remedied by the coating of a mixture of flake graphite powder and heat resistance paint. Consequently, no heat treatment is necessary to eliminate these three types of deflection. (4) Introduction of a new specification concerning the heat indication test. At the heat indication test, only types B and C should be examined closely. The rotor forgings showing other types of deflection i.e. A, D and C' are not ccnsidered unsuitable as turbine or generator rotors.