Evaluation of Microstructure and Mechanical Properties of Seamless Steel Pipes API 5L Type Obtained by Different Processes of Heat Treatments

This research presents the influence of manufacturing processes and heat treatments on the resulting microstructures and mechanical properties of an API 5L PSL2 seamless steel pipe. Three different conditions are considered - as rolled, normalized and quenched and tempered - to obtain the grades X42R, X42N and X70Q, respectively. Scanning electron microscopy techniques was used to characterize the resultant microstructures. Tensile, hardness, impact, fracture toughness (J integral) and fatigue crack growth tests (da/dN x ΔK) were used to study the materials mechanical behavior. The results sh...