|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Late News Posters
||PP-53: Investigation of Microstructural Variation on Yield Strength of X-70M Spiral Welded Line Pipe Steel
||Ashish Singh, Pushpendra N Mahida, Pankaj Mittal
|On-Site Speaker (Planned)
Development of high strength line pipe steel is crucial for safe and cost-effective transportation of oil and gas across the world. Acicular ferrite (AF) micro structure is desired for the optimized properties including high strength and high toughness of thermo-mechanical control processed (TMCP) steel. Even though a lot of efforts are made in optimizing the chemical composition and TMCP parameters of line pipe steel, localized low yield strength regions were observed during hydro testing of spiral pipes having thickness 10.9mm and diameter 762 mm. In order to better understand these localized low yield strength regions, microstructural and mechanical characterizations were performed. Higher amount of pearlite bands and grain size variation were observed in the low yield strength region when compared to acicular ferrite microstructure in high yield strength regions. Various hot rolling conditions which resulted in localized low yield strength properties were investigated.