Synthetic S–N curves for sintered steels based on density, hardness, and local stress parameters: A data analysis

While components produced by melt metallurgy have long been subject to established rule sets for proof of strength, a comparable guideline has now been developed for press-and-sinter powder metallurgical components, taking into account their characteristic residual porosity. This paper presents a method that enables the generation of a synthetic S–N curve using hardness, density, and local stress parameters as input parameters. The development of this method required a comprehensive literature review, gathering data on fatigue strength parameters in relation to density, hardness, as well as specimen geometry and load information. The compiled data was utilized to deduce relationships and formulate an algorithm capable of estimating fatigue strength associated with a 50% failure probability. Moreover, the method can supply information regarding the S–N curve’s trajectory within the finite life region. Coupled with results on statistical scatter derived from the literature, comprehensive synthetic S–N curves for sintered steels can be constructed.