Abstract: The reliability and stability of materials is the base for the structural safety assessment. The mechanical property parameters of GH4133B superalloy used in turbine disk of a type of aero-engine are measured at ambient temperature, and analyzed by using the statistical analysis technique. The mechanical property parameters, such as tensile strength, yield strength, percentage elongation, reduction of cross-section area, Brinell hardness and impact toughness, are statistically analyzed by using the normal probability density function, and DAgostino test procedure is adopted to detect the statistical results. The mean-range chart is introduced to examine the periodical stability of GH4133B at different test stages. The global stability and reliability of mechanical property parameters of GH4133B are investigated by using Weibull distribution model. The results demonstrate that the mechanical parameters of GH4133B, whose values possess the property of periodical stability, are fitted with the normal probability density function approximately. The three-parameter Weibull distribution is fit for the reliability assessment of GH4133B. The global stability and reliability of GH4133B all meet the requirements of practical service and application.

Key words: Mechanical property, Reliability, Stability, Statistical analysis, Turbine disk