Abstract: Disclosed herein is a nickel-based heat-resistant material with improved cyclic oxidation properties. The nickel-based heat-resistant material containing gadolinium (Gd) according to the present invention is capable of suppressing the de-lamination of an oxide layer and increasing stability of the oxide layer, thereby forming an overall thin and uniform oxide layer, and has an advantage in that the formation of a nitride may be suppressed since nitrogen is prevented from penetrating through the oxide layer. In addition, due to the slow oxidation rate, there is an advantage in that an Al depletion layer (a ?? denuded zone) by the formation of an oxide layer may be formed to be very thin compared to that of a specimen having no gadolinium added.

Abstract: Disclosed herein is a nickel-based heat-resistant material with improved cyclic oxidation properties. The nickel-based heat-resistant material containing gadolinium (Gd) according to the present invention is capable of suppressing the de-lamination of an oxide layer and increasing stability of the oxide layer, thereby forming an overall thin and uniform oxide layer, and has an advantage in that the formation of a nitride may be suppressed since nitrogen is prevented from penetrating through the oxide layer. In addition, due to the slow oxidation rate, there is an advantage in that an Al depletion layer (a ?? denuded zone) by the formation of an oxide layer may be formed to be very thin compared to that of a specimen having no gadolinium added.

Abstract: According to the present invention, a Ni-base superalloy is comprised 2.0 to 6.0 wt. % of cobalt (Co), 8.0 to 12.0 wt. % of chromium (Cr), 5.0 to 9.0 wt. % of tungsten (W), 3.5 to 6.0 wt. % of aluminum (Al), 3.0 wt. % or less of titanium (Ti), 5.0 to 10.0 wt. % of tantalum (Ta), 0.05 to 0.15 wt. % of carbon (C), 0.02 wt. % or less of boron (B), 0.05 wt. % or less of zirconium (Zr), with the remainder being composed of nickel (Ni) and unavoidable impurities.

Abstract: The present disclosure relates to a Ni-based superalloy with excellent oxidation resistance and creep properties, which is suitable for parts of energy plants and chemical plants under a corrosive oxidative/reductive atmosphere, which stainless steel cannot withstand, through adjustment of alloy components and control of process conditions and a method of manufacturing the same. The Ni-based superalloy includes: chromium (Cr): 20˜26 wt %, tungsten (W): 13˜17 wt %, molybdenum (Mo): 1˜5 wt %, manganese (Mn): 0.1˜1.0 wt %, silicon (Si): 0.1˜0.6 wt %, aluminum (Al): 0.1˜1.0 wt %, lanthanum (La): 0.01˜0.06 wt %, carbon (C): 0.01˜0.20 wt %, and the balance of nickel (Ni) and unavoidable impurities.

Abstract: There is provided a method for alloy design combining a response surface method and an artificial neural network that can significantly reduce the number of times, the time, and the cost for experiments by designing the minimum experiments using a response surface method, obtaining results through actual experiments, and modeling the obtained results using an artificial neural network. The method for alloy design combining a response surface method and an artificial neural network designs an experiment using a response surface method, obtains a result through an actual experiment, and models alloy composition by applying the obtained result to an artificial neural network.

Abstract: A Ni-based single crystal superalloy with good resistance to creep deformation and creep life at a high temperature is formed by adjusting the quantity of relatively inexpensive alloy elements while minimizing the quantity of expensive alloy elements. The Ni-based single crystal superalloy with good creep properties comprises Co: 11.5˜13.5%, Cr: 3.0˜5.0%, Mo: 0.7˜2.0%, W: 8.5˜10.5%, Al: 4.5˜6.5%, Ti: 0.5˜2.0%, Ta: 6.0˜8.0%, Re: 2.0˜4.0%, Ru: 0.1˜2.0% in Weight %, with the rest of the superalloy comprising Ni and other inevitable impurities. In addition, the superalloy has a mixed structure of the ? matrix and ?? particles.

Abstract: An apparatus and method for measuring the crystallographic orientation relationship of neighboring grains and the characteristics of grain boundaries using a goniometer of a transmission electron microscope are disclosed to check the orientation relationship between two crystals and the characteristics of grain boundaries with a small error in real time. An apparatus for measuring the orientation relationship between neighboring grains and the characteristics of grain boundaries by using a goniometer of a transmission electron stereoscope, the apparatus comprising a goniometer mounted at a transmission electron microscope and a measurement unit for revealing the characteristics of grain boundaries of a specimen by linear-algebraically interpreting the relationship between crystal axes and tilt axes of the specimen using the goniometer.

Abstract: An apparatus and method for measuring the crystallographic orientation relationship of neighboring grains and the characteristics of grain boundaries using a goniometer of a transmission electron microscope are disclosed to check the orientation relationship between two crystals and the characteristics of grain boundaries with a small error in real time. An apparatus for measuring the orientation relationship between neighboring grains and the characteristics of grain boundaries by using a goniometer of a transmission electron stereoscope, the apparatus comprising a goniometer mounted at a transmission electron microscope and a measurement unit for revealing the characteristics of grain boundaries of a specimen by linear-algebraically interpreting the relationship between crystal axes and tilt axes of the specimen using the goniometer.

Abstract: The present invention suggests a method of heat treatment of a Ni-based superalloy that improves resistance against creep, fatigue and stress corrosion cracking while being economical and easy, and a Ni-based superalloy produced by using the same. The method and the superalloy of the present invention include solution treatment at the high temperature region during a heat treatment process after manufacturing or final cold working fabrication. Immediately following the solution treatment, the material is slowly cooled at 1˜15° C./minute down to the intermediate temperature region for aging treatment. After the slow cooling stage, aging treatment is directly performed by holding it at the intermediate temperature region for the prescribed time. Lastly, the aging treatment is followed by air-cooling stage.