摘要:
A Ni-added steel plate contains, by mass %, C: 0.03% to 0.10%, Si: 0.02% to 0.40%, Mn: 0.3% to 1.2%, Ni: 5.0% to 7.5%, Cr: 0.4% to 1.5%, Mo: 0.02% to 0.4%, Al: 0.01% to 0.08%, T.O: 0.0001% to 0.0050%, P: limited to 0.0100% or less, S: limited to 0.0035% or less, and N: limited to 0.0070% or less with a remainder composed of Fe and inevitable impurities, in which a Ni segregation ratio at a position of ¼ of a plate thickness away from a plate surface in a thickness direction is 1.3 or less, a fraction of austenite after deep cooling is 2% or more, an austenite unevenness index after deep cooling is 5.0 or less, and an average equivalent circle diameter of austenite after deep cooling is 1 μm or less.
摘要:
A Ni-added steel plate contains, by mass %, C: 0.03% to 0.10%, Si: 0.02% to 0.40%, Mn: 0.3% to 1.2%, Ni: 5.0% to 7.5%, Cr: 0.4% to 1.5%, Mo: 0.02% to 0.4%, Al: 0.01% to 0.08%, T•O: 0.0001% to 0.0050%, P: limited to 0.0100% or less, S: limited to 0.0035% or less, and N: limited to 0.0070% or less with a remainder composed of Fe and inevitable impurities, in which a Ni segregation ratio at a position of ¼ of a plate thickness away from a plate surface in a thickness direction is 1.3 or less, a fraction of austenite after deep cooling is 2% or more, an austenite unevenness index after deep cooling is 5.0 or less, and an average equivalent circle diameter of austenite after deep cooling is 1 μm or less.
摘要:
A steel for a welded structure includes the following composition: by mass %, C at a C content [C] of 0.015 to 0.045%; Si at a Si content [Si] of 0.05 to 0.20%; Mn at a Mn content [Mn] of 1.5 to 2.0%; Ni at a Ni content [Ni] of 0.10 to 1.50%; Ti at a Ti content [Ti] of 0.005 to 0.015%; O at an O content [O] of 0.0015 to 0.0035%; and N at a N content [N] of 0.002 to 0.006%, and a balance composed of Fe and unavoidable impurities. In the steel for a welded structure, the P content [P] is limited to 0.008% or less, the S content [S] is limited to 0.005% or less, the Al content [Al] is limited to 0.004% or less, the Nb content [Nb] is limited to 0.005% or less, the Cu content [Cu] is limited to 0.24% or less, the V content [V] is limited to 0.020% or less, and a steel composition parameter PCTOD is 0.065% or less, and a steel composition hardness parameter CeqH is 0.235% or less.
摘要:
The present invention provides high strength steel having unprecedentedly superior CTOD (fracture toughness) properties satisfying not only the CTOD properties of the FL zone at −60° C., but also the CTOD properties of the ICHAZ zone in small and medium heat input multilayer welding etc. and a method of production of the same.The steel of the present invention is steel superior in CTOD properties of the heat-affected zone containing, by mass %, C: 0.015 to 0.045%, Si: 0.05 to 0.2%, Mn: 1.5 to 2.0%, Cu: 0.25 to 0.5%, Ni: 0.7 to 1.5%, P: 0.008% or less, S: 0.005% or less, Al: 0.004% or less, Ti: 0.005 to 0.015%, Nb: 0.005% or less, 0: 0.0015 to 0.0035%, and N: 0.002 to 0.006%, PCTOD: 0.065 or less, CeqH: 0.235 or less and the balance consisting of Fe and unavoidable impurities.
摘要:
In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by a fluorescent X-ray analysis method using an energy dispersion type spectroscope, or by other chemical or physical measurements, to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.
摘要:
A steel having excellent HAZ toughness can be used for ships, buildings, pressure containers, linepipes, and so forth. The steel is of a Ti--Mg--O system steel containing at least 40 pcs/mm.sup.2 of oxide and composite oxide particles of Ti and Mg having a size of 0.001 to 5.0 .mu.m. A steel having excellent HAZ toughness can be produced, and the safety of structures using this steel can be remarkably improved.
摘要:
A Ti--Al intermetallic compound has a compressibility of at least 25% at room temperature and a superior high temperature oxidation resistance and consists essentially of about 40 to 52 atomic percent of Ti, about 48 to 60 atomic percent of Al, and 10 to 1000 atomic ppm of at least one of P, As, Se, or Te.
摘要:
A steel for a welded structure includes the following composition: by mass %, C at a C content [C] of 0.010 to 0.065%; Si at a Si content [Si] of 0.05 to 0.20%; Mn at a Mn content [Mn] of 1.52 to 2.70%; Ni at a Ni content [Ni] of 0.10% to 1.50%; Ti at a Ti content [Ti] of 0.005 to 0.015%; O at an O content [O] of 0.0010 to 0.0045%; N at a N content [N] of 0.002 to 0.006%; Mg at a Mg content [Mg] of 0.0003 to 0.003%; Ca at a Ca content [Ca] of 0.0003 to 0.003%; and the balance composed of Fe and unavoidable impurities. A steel component parameter PCTOD is 0.065% or less, and a steel component hardness parameter CeqH is 0.235% or less.
摘要:
The present invention provides a common rail formed by bonding a common rail body and a common rail holder which has a pressing surface and a convex bonding surface, by means of a heat pressure bonding process and a liquid phase diffusion bonding process, wherein the height H of the convex bonding surface satisfies 1 μm≦H≦50 μm, and the common rail holder includes a deformation introducing portion in which an area of a cross-section parallel to the pressing surface is smaller than the area of the pressing surface.
摘要:
A method of production of 780 MPa class high strength steel plate excellent low temperature toughness comprising heating a steel slab of containing, by mass %, C: 0.06 to 0.15%, Si: 0.05 to 0.35%, Mn: 0.60 to 2.00%, P: 0.015% or less, S: 0.015% or less, Cu: 0.1 to 0.5%, Ni: 0.1 to 1.5%, Cr: 0.05 to 0.8%, Mo: 0.05 to 0.6%, Nb: less than 0.005%, V: 0.005 to 0.060%, Ti: less than 0.003%, Al: 0.02 to 0.10%, B: 0.0005 to 0.003%, and N: 0.002 to 0.006% to 1050° C. to 1200° C. in temperature, hot rolling ending at 870° C. or more, waiting for 10 seconds to 90 seconds, then cooling from 840° C. or more in temperature by a 5° C./s or more cooling rate to 200° C., then tempering at 450° C. to 650° C. in temperature for 20 minutes to 60 minutes.