33results about How to "Production cost economy" patented technology

The invention discloses low-temperature X80HD (High Density) large-deformation pipeline steel with great wall thickness and a production method thereof, belonging to the technical field of medium-thickness plate production and longitudinal submerged arc welded tube production. A steel plate comprises the following chemical components in percentage by mass: not less than 0.04% and not greater than 0.09% of C, not greater than 0.35% of Si, not less than 1.5% and not greater than 1.85% of Mn, not greater than 0.012% of P, not greater than 0.004% of S, not less than 0.02% and not greater than 0.05% of Nb, not less than 0.008% and not greater than 0.025% of Ti, not less than 0.10% and not greater than 0.50% of Ni, not less than 0.10% and not greater than 0.45% of Cr, not less than 0.10% and not greater than 0.30% of Cu, not less than 0.10% and not greater than 0.35% of Mo, not less than 0.020% and not greater than 0.070% of Alt, not greater than 0.0005% of B, not greater than 0.0050% of Ca, and the balance of Fe and inevitable impurities. A preparation method of the steel plate comprises the processes such as converter smelting, external refining, continuous casting, heating, controlled rolling, relaxation phase change control and quick cooling; a texture of the rolled steel plate is ferrite, bainite and a little M / A (Martensite / Austenite), wherein ferrite content is 60%-85%, and bainite and M / A content is 15%-40%. The obtained X80HD large-deformation pipeline steel has high strength and toughness, a high work-hardening index, high uniform ductility, a low yield ratio and good deformation resistance.