The present invention provides a gas turbine combustor that has a fuel injection nozzle using a fluid other than liquid fuel to atomize the liquid fuel and that can suppress a reduction in power generation efficiency resulting from a heat loss while promoting the atomization of the liquid fuel. The gas turbine combustor is adapted to mix liquid fuel with combustion air led from a compressor, burn the mixture, and supply combustion gas generated to a gas turbine. The gas turbine combustor includes a fuel injection nozzle that atomizes the liquid fuel into fine liquid droplets. The fuel injection nozzle includes a first system adapted to supply the liquid fuel and a second system adapted to supply a fluid for atomizing the liquid fuel. Low-boiling liquid fuel is supplied to the second system as the fluid. The second system is adapted to heat and supply the low-boiling liquid fuel.

Gas turbine combustor

Stability of (Ti, M)C (M = Nb, V, Mo and W) carbide in steels using first-principles calculations

Thermomechanical processing of advanced high strength steels

Interphase precipitation of nanometer-sized carbides in a titanium–molybdenum-bearing low-carbon steel

The effects of Ti, Ti–Mo, and Ti–Nb microalloy additions on the precipitation strengthening in three experimental high-strength low-alloy steels have been investigated. The objective of this work was to study the carbide precipitation under the conditions of continuous cooling and interrupted cooling. It was found that titanium molybdenum complex carbide, (Ti, Mo)C, can strongly maintain nanometer-scaled sizes and has the largest contribution to the hardness as compared to titanium carbide, TiC, and titanium niobium complex carbide, (Ti, Nb)C. The result emphasizes that (Ti, Mo)C particles possess an excellent behavior of thermal stability.

Precipitation hardening of high-strength low-alloy steels by nanometer-sized carbides

A ferritic steel precipitation-strengthened by manometer-sized carbides was developed to obtain a high strength hot-rolled sheet steel having tensile strength of 780 MPa grade with excellent stretch flange formability. Manganese in a content of 1.5% and molybdenum in a content of 0.2 % were added to 0.04 % carbon Ti-bearing steel in order to lower austenite-ferrite transformation temperature for fine carbides and to retard generating of pearlite and large cementites, respectively. Tensile strength of hot-rolled sheet steel increased with titanium content and it was achieved to 800 MPa in a 0.09 % Ti steel. Microstructure of the 0.09 %Ti steel was ferrite without pearlite and large cementites. Fine carbides of 3 nm in diameter were observed in rows in the ferrite matrix of the 0.09 % Ti steel with transmission electron microscope. The characteristic arrangement of the nanometer-sized carbides indicates that the carbides were formed at austenite-ferrite interfaces during transformation. By energy dispersive X-ray spectroscopy, the carbides were found to contain molybdenum in the same atomic concentration as titanium. Crystal structure of the nanometer-sized carbides was determined to be NaCI-type by X-ray diffractometry. The calculated amount of precipitation-strengthening by the carbides was approximately 300 MPa. This is two or three times higher than that of conventional Ti-bearing high strength hot-rolled sheet steels. Based on the results obtained in the laboratory investigation, mill trial was carried out. The developed hot-rolled high strength sheet steel exhibited excellent stretch flange formability.

Development of High Strength Hot-rolled Sheet Steel Consisting of Ferrite and Nanometer-sized Carbides

Disclosed are an ultra-high-strength steel sheet having both a tensile strength of as high as 1400MPa or above and excellent formability and an advantageous process for manufacturing the same. A high-strength steel sheet having both a composition which contains by mass C: 0.12 to 0.50%, Si: 2.0% or less, Mn: 1.0 to 5.0%, P: 0.1% or less, S: 0.07% or less, Al: 1.0% or less, and N: 0.008% or less with the balance being Fe and unavoidable impurities, and a structure which comprises, in terms of area fraction, autotempered martensite: 80% or more, ferrite: less than 5%, bainite: 10% or less, and retained austenite: 5% or less and in which the average number of precipitated iron carbide particles of 5nm to 0.5[mu]m in the autotempered martensite is 5OE04 or above per mm2.

High-strength steel sheet and process for production thereof

Disclosed is a high-strength steel plate having superior ductility and stretch flangeability and a tensile strength (TS) of 980 MPa or higher, and having 0.17-0.73% C, 3.0% or less Si, 0.5-3.0 or less Mn, 0.1% or less P, 0.07% S, 3.0% or less Al, 0.010% or less N, and 0.7% or more Si + Al, an area ratio of martensite of 10-90% with respect to the entire steel plate composition, a residual austenite amount of 5-50%, and an area ratio of bainitic ferrite in the upper bainite of 5% or less with respect to the entire steel plate composition. Twenty-five percent or more of the aforementioned martensite is tempered martensite, and the total of the area ratio of the aforementioned martensite with respect to the entire steel plate composition, the aforementioned residual austenite amount and the area ratio of the aforementioned bainitic ferrite in the upper bainite with respect to the entire steel plate composition is 65% or more. The area ratio of polygonal ferrite with respect to the entire steel plate composition is 10% or less (including 0%), and the average amount of C in the aforementioned residual austenite is 0.70% or more.

High-strength steel plate and manufacturing method thereof

A high strength pressed member has excellent ductility and stretch flangeability and tensile strength of 780-1400 MPa, with a predetermined steel composition and steel microstructure relative to the entire microstructure of steel sheet, where area ratio of martensite 5-70%, area ratio of retained austenite 5-40%, area ratio of bainitic ferrite in upper bainite 5% or more, and total thereof is 40% or more, 25% or more of martensite is tempered martensite, polygonal ferrite area ratio is above 10% and below 50% to the entire microstructure of steel sheet, and average grain size is 8 μm or less, average diameter of a group of polygonal ferrite grains is 15 μm or less, the group of polygonal ferrite grains represented by a group of ferrite grains of adjacent polygonal ferrite grains, and average carbon content in retained austenite is 0.70 mass % or more and tensile strength is 780 MPa or more.

High-strength steel sheet and method for manufacturing same

PROBLEM TO BE SOLVED: To provide a hot press member having excellent ductility which has TS of 1,300 to 1,450 MPa and El of ≥8%, to provide a steel sheet for the hot press member, and to provide a method for producing the hot press member. SOLUTION: The hot press member having excellent ductility has a composition comprising, by mass, 0.15 to 0.30% C, 0.05 to 3.0% Si, 1.0 to 4.0% Mn, ≤0.05% P, ≤0.05% S, 0.005 to 0.1% Al and ≤0.01% N, and the balance Fe with inevitable impurities, and has a microstructure where the area ratio of a ferritic phase occupied in the whole structure is 5 to 65%, the area ratio of a martensitic phase occupied in the whole structure is 35 to 95%, and also, the average grain size of the ferritic phase and the martensitic phase is ≤7 μm. COPYRIGHT: (C)2010,JPO&INPIT

Yoshimasa Funakawa

Papers

Development of High Strength Hot-rolled Sheet Steel Consisting of Ferrite and Nanometer-sized Carbides

High-strength steel sheet and process for production thereof

High-strength steel plate and manufacturing method thereof

High-strength steel sheet and method for manufacturing same

Hot press member having excellent ductility, steel sheet for the hot press member and method for producing the hot press member