Transição dúctil-frágil do aço naval ASTM A 131

Abstract

The shipbuilding industry appears quite advanced in terms of construction, materials development and in relation to the study of new manufacturing processes. When it comes to steel applied to the shipping industry, is clearly identified in this scenario the ASTM A131 steel, used in the construction of offshore oil drilling in vessels of medium and large, which has high strength, good toughness, and good weldability. In this work the transition from ductile-brittle behavior of ship steel ASTM A131 Grade A was lifted performing Charpy impact tests at various temperatures. The assay was performed in standardized specimens in accordance with ASTM E23, which were subjected to various temperatures between 200 ° C and -50 ° C. The curve of energy absorbed versus temperature allowed determination of the material parameters and this temperature range at which the material undergoes changes from ductile to brittle. The measured change in impact resistance with temperature, the mechanism of fracture, the fracture surface characteristics analyzed using the technique of Scanning Electron Microscopy (SEM) and stereomicroscopy was used as a way to determine the existence of this transition ductile fragile steel.