Carbon and low-alloy steels are susceptible to brittle fracture at low temperatures.  However, “low temperature” is a relative term.  Some steels are brittle at ambient temperature, while other steels remain ductile down to temperatures well below ambient.

The API579-1/ASME FFS-1 fitness-for-service  standard includes an assessment of brittle fracture in carbon and low-alloy steel pressure vessels, piping, and storage tanks.  This assessment, which is based primarily on Section VIII of the ASME Boiler and Pressure Vessel Code, compares the lowest anticipated operating temperature with the minimum allowable operating temperature of the material of construction.

Quest Reliability can perform brittle fracture assessments of critical assets in accordance with API 579-1/ASME FFS-1.  Moreover, we can go beyond the standard assessment when necessary.  Levels 1 and 2 of the API/ASME brittle fracture assessment suffer from a number of limitations.  For example, they do not account for the presence of planar flaws, weld residual stress or transient thermal stresses.  When one or more of these factors are present, we perform a rigorous fracture mechanics analysis of the component of interest in order to assess the risk of brittle fracture.

For further information about Brittle Fracture Assessment please contact us.