Algorithms to Estimate the Ductile to Brittle Transition Temperature, Upper Shelf Energy, and Their Uncertainties for Steel Using Charpy V-Notch Shear Area and Absorbed Energy Data

Toughness and the transition from ductile to brittle behavior are long-standing concerns for applications of ferritic steel such as line-pipe. Three algorithms have been developed fit a hyperbolic tangent curve any Charpy V-notch dataset estimate uncertainty (1) 85% shear appearance area temperature (2) upper shelf absorbed energy. To data (I) first algorithm relied on iterative estimation four-parameters; (II) second two parameters (after simplification based physical assumptions); (III) third only one parameter further simplification). The were written using open-source programing language, R. minimum input requirements experimental energy at least four temperatures four-parameter algorithm, two-parameter one-parameter algorithm. test quantity tests each can vary. described in detail demonstrated set 12 results (shear energy) API-5L grade X52 pipe with 4.5 mm thick bars. A future paper will compare wide variety sets clarify their applicability possible limitations.