DALMINE S.P.A. Patent applications |
Patent application number | Title | Published |
20140299236 | HIGH STRENGTH MEDIUM WALL QUENCHED AND TEMPERED SEAMLESS STEEL PIPES AND RELATED METHOD FOR MANUFACTURING SAID STEEL PIPES - Disclosed herein are embodiments of a seamless quenched and tempered steel pipe which can have a wall thickness WT higher than or equal to 6 mm and lower than or equal to 35 mm. Some embodiments of the steel pipe can have a chemical composition comprising C, Mn, Si, Cr, Ni, Mo, Al, N, Ca, Nb, Ti, V, Zr, and Ta based on the composition weight, the remaining being iron and impurities. In some embodiments, wherein (V+Nb) content is lower than 0.07 wt %; defining a first parameter P1=(60×C)+Cr+[5×e | 10-09-2014 |
20140299235 | HEAVY WALL QUENCHED AND TEMPERED SEAMLESS STEEL PIPES AND RELATED METHOD FOR MANUFACTURING SAID STEEL PIPES - Disclosed herein are embodiments of a seamless quenched and tempered steel pipe having a wall thickness (WT) higher than or equal to 35 mm and lower than or equal to 80 mm. Embodiments of the steel pipe can comprise C, Mn, Cr, Ni, Mo, Al, Ca, N, Nb, Ti, Zr, and Ta. Further, for some embodiments of the steel pipe wherein, defining a first parameter P1=50×C+Cr+10×Mo+70×V, the chemical composition can satisfy a first condition P1≦8.0. | 10-09-2014 |
20120204994 | HEAVY WALL STEEL PIPES WITH EXCELLENT TOUGHNESS AT LOW TEMPERATURE AND SULFIDE STRESS CORROSION CRACKING RESISTANCE - Embodiments of the present disclosure comprise carbon steels and methods of manufacturing thick walled pipes (wall thickness greater than or equal to about 35 mm) there from. In one embodiment, a steel composition is processed that yields an average prior austenite grain size greater than about 15 or 20 μm and smaller than about 100 μm. Using this composition, a quenching sequence is provided that yields a microstructure of greater than or equal to about 50% by volume, and less than or equal to about 50% by volume, lower bainite, without substantial ferrite, upper bainite, or granular bainite. After quenching, pipes may be tempered. The quenched and tempered pipes may exhibit yield strengths greater than about 450 MPa (65 ksi) or 485 (70 ksi). Mechanical property measurements find the quenched and tempered pipes suitable for 450 MPa grade and 485 MPa grade, and resistance to sulfide stress corrosion cracking. | 08-16-2012 |
20120199255 | HIGH STRENGTH STEEL PIPES WITH EXCELLENT TOUGHNESS AT LOW TEMPERATURE AND SULFIDE STRESS CORROSION CRACKING RESISTANCE - Low-alloy steels and methods of manufacturing pipes having a wall thickness greater than or equal to about 8 mm and less than or equal to about 35 mm therefrom are provided. In one embodiment, a steel composition is processed that yields an average prior austenite grain size greater than about 15 or 20 μm and smaller than about 100 μm. A quenching sequence has been determined that yields a microstructure of greater than or equal to about 60% martensite by volume, and less than or equal to about 40% by volume lower bainite, without substantial formation of ferrite, upper bainite, or granular bainite. The yield strength of the quenched and tempered pipes may be greater than about 70 ksi, 80 ksi, or 90 ksi. The quenched and tempered pipes are suitable for 70 ksi, 80 ksi, and 90 ksi grades and resistant to sulfide stress corrosion cracking. | 08-09-2012 |