Abstract:
In a method for producing a grain-oriented electrical steel sheet, grooves each having a given length and extending in a direction including a direction perpendicular to a transportation direction of the grain-oriented electrical steel sheet are formed at given intervals in the transportation direction by irradiating the surface of the grain-oriented electrical steel sheet with a laser beam while scanning the surface of the grain-oriented electrical steel sheet with the laser beam. Further, in the method for manufacturing a grain-oriented electrical steel sheet, the laser beam is a continuous-wave laser beam having a laser wavelength λ of 1.0 μm to 2.1 μm, power density Pd [W/mm2] which is obtained by dividing laser beam intensity P by a focused beam area S is 5×105 W/mm2 or more, and the power density Pd [W/mm2] and scanning speed V [mm/s] of a focused spot of the laser beam on the surface of the grain-oriented electrical steel sheet satisfy a relationship of 0.005×Pd+3000≦V≦0.005×Pd+40000.
Abstract:
A predetermined steel containing Te: 0.0005 mass % to 0.0050 mass % is heated to 1320° C. or lower to be subjected to hot rolling, and is subjected to annealing, cold rolling, decarburization annealing, and nitridation annealing, and thereby a decarburized nitrided steel sheet is obtained. Further, an annealing separating agent is applied on the surface of the decarburized nitrided steel sheet and finish annealing is performed, and thereby a glass coating film is formed. The N content of the decarburized nitrided steel sheet is set to 0.0150 mass % to 0.0250 mass % and the relationship of 2×[Te]+[N]≦0.0300 mass % is set to be established. Note that [Te] represents the Te content and [N] represents the N content.
Abstract:
The present invention provides an oriented substrate for forming an epitaxial thin film thereon, which has a more excellent orientation than that of a conventional one and a high strength, and a method for manufacturing the same. The present invention provides a clad textured metal substrate for forming the epitaxial thin film thereon, which includes a metallic layer and a silver layer bonded to at least one face of the metallic layer, wherein the silver layer has a {100} cube texture in which a deviating angle Δφ of crystal axes satisfies Δφ≦9 degree. The textured metal substrate can be manufactured by subjecting the silver sheet containing 30 to 200 ppm oxygen by concentration to the orienting treatment of hot-working and heat-treating, and bonding the metal sheet with the oriented silver sheet by using a surface activated bonding process.
Abstract:
A nitriding treatment (Step S6) in which an N content of a decarburization-annealed steel strip is increased is performed between start of a decarburization annealing (Step S4) and occurrence of secondary recrystallization in a finish annealing (Step S5). In hot rolling (Step S1), a silicon steel material is held in a temperature range between 1000° C. and 800° C. for 300 seconds or longer, and then finish rolling is performed.
Abstract:
A silicon steel material is heated in a predetermined temperature range according to contents of B, N, Mn, S, and Se (step S1), and is subjected to hot rolling (step S2). Further, a finish temperature Tf of finish rolling in the hot rolling is performed in a predetermined temperature range according to the content of B. Through these treatments, a certain amount of BN is made to precipitate compositely on MnS and/or MnSe.
Abstract:
A slab having a predetermined composition is heated to 1280° C. or more. The slab is hot-rolled to obtain a hot-rolled steel sheet. The hot-rolled steel sheet is annealed to obtain an annealed steel sheet. The annealed steel sheet is cold-rolled to obtain a cold-rolled steel sheet. The cold-rolled steel sheet is decarburization annealed to obtain a decarburization annealed steel sheet. The decarburization annealed steel sheet is coiled in a coil state. The coil-state decarburization annealed steel sheet is finish-annealed. The cold-rolled steel sheet is heated to a temperature of 800° C. or more at a rate of 30° C./sec or more and 100° C./sec or less during increasing temperature of the cold-rolled steel sheet in the decarburization annealing or before the decarburization annealing. The decarburization annealed steel sheet is heated at a rate of 20° C./h or less within a temperature range of 750° C. or more and 1150° C. or less during increasing temperature of the decarburization annealed steel sheet in the finish annealing.
Abstract:
The present invention provides high strength hot rolled steel plate for line-pipes superior in low temperature toughness, and a method of production of the same, containing, by mass %, C: 0.01 to 0.1%, Si: 0.05 to 0.5%, Mn: 1 to 2%, P: ≦0.03%, S: ≦0.005%, O: ≦0.003%, Al: 0.005 to 0.05%, N: 0.0015 to 0.006%, Nb: 0.005 to 0.08%, and Ti: 0.005 to 0.02%, where N−14/48×Ti>0% and Nb—93/14×(N−14/48×Ti)>0.005%, and a balance of Fe and unavoidable impurities, said steel plate characterized in that its microstructure is a continuously cooled transformed structure, a reflected X-ray intensity ratio {211}/{111} of the {211} plane and {111} plane parallel to the plate surface in the texture at the center of plate thickness is 1.1 or more, and an in-grain precipitate density of the precipitates of Nb and/or Ti carbonitrides is 1017 to 1018/cm3.
Abstract:
Steel sheet having a high {222} plane integration comprising steel sheet having an Al content of less than 6.5 mass % characterized by one or both of (1) a {222} plane integration of one or both of an αFe phase and γFe phase with respect to the steel sheet surface being 60% to 99% and (2) a {200} plane integration of one or both of an αFe phase and γFe phase with respect to the steel sheet surface being 0.01% to 15%.
Abstract:
The present invention provides a fine grain surface layer steel part having a high proof strength ratio equal to or higher than that of conventional quenched and tempered materials, that is, a fine grain surface layer steel part containing, by mass %, C: 0.45% to 0.70%, Nb: 0.01% to 0.60%, Si: 0.10% to 1.50%, Mn: 0.40% to 2.0%, P: 0.10% or less, S: 0.001% to 0.15%, and N: 0.003% to 0.025% and having a balance of Fe and unavoidable impurities, where the surface layer and inside at all or part of the part have structures of different average particle sizes of ferrite crystal grains surrounded by high angle grain boundaries of a misorientation angle of 15 degrees or more and a method of production of that part comprising warm forging locations where strength is required to a predetermined shape at 1000° C. to 800° C. during which working so as to give an equivalent strain of 1.5 or more.
Abstract:
Reheating a grain-oriented electrical steel sheet slab comprising predetermined components to 1280° C. or more and a solid solution temperature of inhibitor substances or more, hot rolling, annealing, and cold rolling it, decarburization annealing it, nitriding it in a strip running state, coating an annealing separator, and finish annealing it during which making a precipitation ratio of N as AlN after hot rolling 20% or less, making a mean grain size of primary recrystallization 7 μm to less than 20 μm, and making a nitrogen increase ΔN in the nitridation within a range of Equation (1) and making nitrogen contents σN1 and σN2 (front and back, mass %) of a 20% thickness portion of one surface of the steel strip (sheet) within a range of Equation (2): 0.007−([N]−14/48×[Ti])≦ΔN≦[solAl]×14/27−([N]−14/48×[Ti])+0.0025 Equation (1) |σN1−σN2|/ΔN≦0.35 Equation (2)