Lignite based thermal power plant superheater boiler tubes failed very frequently due to several reasons in Turkey and this causes the thermal power plants stops. This thesis consists of an accelerated test apparatus design for the life assessment of thermal power plant boiler tubes. The intended assessment consists of determining the best boiler candidate material which is exposed to corrosion, erosion and creep under thermal power plant condition. The most severe problems in Turkey power plants are 28% erosion, 22% long term overheating (creep) due to deposit formation and 22% short term overheating. The aimed apparatus will simulate the working conditions of super-heater boiler tubes of thermal power plants. In the beginning it is planned to construct three main parts. These main parts are loading system, heating system and blowing system. In the loading system the stress which will be applied to the tubes is increased in order to shorten the test time. For the same purpose the accelerated erosive particles in the blowing system will be chosen larger than the particles in the power plants. The tests are going to be conducted by comparing the material loss of boiler tubes or comparing the rupture times of boiler tubes. In this study, the real life of the boiler tubes will not be determined but the relative lives of boiler tube to each other will be determined in order to choose best material from the available candidate.