Hu Yueyue

Bio: Hu Yueyue is an academic researcher from Zhengzhou University. The author has contributed to research in topics: Ultimate tensile strength & Martensite. The author has an hindex of 5, co-authored 6 publications receiving 67 citations.

Effect of initial microstructures on the properties of Ferrite-Martensite Dual-Phase pipeline steels with Strain-Based design

Abstract: This study aims to investigate the effect of initial microstructures on the properties of ferritemartensite dual-phase pipeline steels with strain-based design. For this purpose, the as-received acicular ferrite steels were first austenitized at 920 °C for 15 minutes followed by air cooling and water quenching to produce ferrite-pearlite and ferrite-martensite microstructure, respectively. Subsequently, the steels with ferrite-pearlite, ferrite-martensite and as-received acicular ferrite microstructure were intercritically annealed at 820 °C for 10 minutes followed by water quenching to produce three different ferrite-martensite dual-phase microstructures. Tensile tests, Vickers hardness and Charpy impact tests were carried out to investigate the mechanical properties. Scanning electron microscope was used to analyze the microstructures and tensile fractographs. The results showed that all the tensile specimens of these three different ferrite-martensite dual-phase steels fractured in ductile mode, however, their microstructures and mechanical properties varied significantly. By contrast, the ferrite-martensite dual-phase steel derived from acicular ferrite initial microstructure had optimal combination of the strength, toughness and deformability, which provided a good candidate for the pipeline steels with strain-based design used in severe geological environments.

Hot-rolling large-deformation-resistance pipeline steel and preparation method thereof

Abstract: The invention discloses a hot-rolling large-deformation-resistance pipeline steel and a preparation method thereof. The hot-rolling large-deformation-resistance pipeline steel comprises the following components in percentage by mass: not more than 0.12% of C, not more than 0.35% of Si, not more than 2.0% of Mn, not more than 0.02% of P, not more than 0.01% of S, not more than 0.11% of Nb, not more than 0.08% of V, not more than 0.05% of Ti, not more than 0.06% of Al, not more than 0.012% of N, not more than 0.50% of Cu, not more than 0.60% of Cr, not more than 0.50% of Mo, not more than 0.60% of Ni, not more than 0.005% of B, not more than 0.01% of Ca and the balance of Fe and inevitable impurities. The preparation method comprises the following steps of: carrying out air cooling after hot rolling, and then carrying out water cooling to 100-300 DEG C or immediately carrying out water cooling to 100-300 DEG C after hot rolling, wherein the tensile strength of the steel is not less than 600MPa. The hot-rolling large-deformation-resistance pipeline steel has higher strain hardening index, larger uniform elongation and lower yield ratio, thereby having higher deformation-resistance capacity than that of the common pipeline steels. A steel plate with the thickness of 10-25mum is made into a steel pipe so that the pipeline steel can meet the high-pressure conveying requirements of petroleum and natural gas.

Effect of holding time at an intercritical temperature on the microstructure and tensile properties of a ferrite-martensite dual phase steel

Abstract: Fil: Balbi, Marcela Angela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Rosario. Instituto de Fisica de Rosario. Universidad Nacional de Rosario. Instituto de Fisica de Rosario; Argentina