|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||High Performance Steels
||Understanding Microstructural Evolution in a Thick Gauge High Strength Niobium-microalloyed Line Pipe Steel
||Monowar Hossain, Xingshuo Wen, Michael Mulholland, Bertram Ehrhardt, Steven Jansto , Gregory Thompson, Nilesh Kumar
|On-Site Speaker (Planned)
For higher productivity, oil and gas are increasingly being transported at higher pressures through steel pipelines which has necessitated development of thick gauge high strength – high toughness line pipe steels. In this work, the microstructural evolution of Nb-microalloyed API Grade X70 line pipe steel has been investigated to understand microstructural variation across the thickness of the 22 mm hot-rolled steel samples from hot-band coils for spiral pipe. The microstructure of the steel sample was probed using optical microscope, scanning electron microscope, and electron backscattered diffraction to characterize different phases, grain size, grain boundary character, aspect ratio, and texture. These microstructural parameters were observed to vary across the depth of the plate. TEM analysis of the steel is performed to characterize and quantify nano-sized Nb containing precipitates. An in-depth understanding of microstructure of the steel will allow its correlation with and prediction of mechanical properties such as ductile-brittle transition temperature.
||Iron and Steel, Characterization, Other