| 摘要 |
#CMT# #/CMT# Process for heat treatment for crack desensitizing assisted by a nickel (Ni)-based alloy environment of composition comprising (in wt.%) e.g. carbon (C) (= 0.10), manganese (Mn) (= 0.5), silicon (Si) (= 0.5), phosphorus (P) (= 0.015), sulfur (S) (= 0.015), Ni (>= 40), chromium (Cr) (12-40), cobalt (Co) (= 10), aluminum (Al) (= 5), molybdenum (Mo) (0.1-15), titanium (Ti) (= 5), boron (B) (= 0.01), copper (Cu) (= 5), and tungsten (W) (0.1-15 ), comprises maintaining the alloy at 950-1160[deg] C in an atmosphere containing 100 ppm of hydrogen mixed with neutral gas or in pure hydrogen. #CMT# : #/CMT# Process for heat treatment for crack desensitizing assisted by a nickel (Ni)-based alloy environment of composition comprising (in wt.%), carbon (C) (= 0.10), manganese (Mn) (= 0.5), silicon (Si) (= 0.5), phosphorus (P) (= 0.015), sulfur (S) (= 0.015), Ni (>= 40), chromium (Cr) (12-40), cobalt (Co) (= 10), aluminum (Al) (= 5), molybdenum (Mo) (0.1-15), titanium (Ti) (= 5), boron (B) (= 0.01), copper (Cu) (= 5), tungsten (W) (0.1-15 ), niobium (Nb) (0-10), tantalum (Ta) (= 10), and the remainder of iron (Fe), and unavoidable impurities obtained by elaboration, comprises maintaining the alloy at 950-1160[deg] C in an atmosphere containing 100 ppm of hydrogen mixed with neutral gas or in pure hydrogen. Independent claims are included for: (1) a manufacturing process of a piece of Ni-based alloy composition, comprising the heat treatment of crack desensitization assisted by the alloy environment; and (2) a part made of a Ni-based alloy, where the alloy is subjected to the heat treatment of desensitization. #CMT#USE : #/CMT# The process is useful to make structural components for nuclear reactors or fuel assemblies inserted into such reactors. #CMT#ADVANTAGE : #/CMT# The alloy has a good resistance: at high temperature and pressure; and against oxidation, corrosion, fluids and thermal or mechanical constraints. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Process: The crack desensitization treatment is carried out: at 950-1010[deg] C, preferably 1010-1160[deg] C; and on a semi-finished product, intended to undergo a treatment for changing its metallurgical structure. The treatment is an annealing, recrystallizing, mixing in solution or hardening, and carried out in non-oxidizing atmosphere. The treatment of crack desensitization is done on a product not undergoing the treatment for changing its metallurgical structure. The process further comprises machining and/or polishing of the alloy after desensitization. The desensitization treatment is carried out in the presence of a compound having a stronger affinity for oxygen than the alloy. In the desensitization treatment, the nickel-based alloy is placed in a case comprising walls made of metal alloys or compound, preferably the alloy is placed in a powder of metal or alloy or compound. Preferred Composition: The alloy composition comprises (in wt.%) C (= 0.08), Mn (= 0.35), Si (= 0.35), P (= 0.015), S (= 0.015), Ni(50-55), Cr (17-21), Co (= 1), Al (0.2-0.8), Mo (2.8-3.3), Ti (0.65-1.15), B (= 0.006), Cu (0.3), mixture of Nb and Ta (4.75-5.5), and the remainder of Fe and unavoidable impurities obtained by elaboration. Preferred Components: The nickel-based alloy is wrapped in a metal strip or alloy or compound having a stronger affinity for oxygen than that of nickel-based alloy, during the desensitization treatment. The compound is a metal comprising aluminum, zirconium, titanium, hafnium, or an alloy containing one of the metals or a compound of element comprising magnesium or calcium. The part is: an element for nuclear reactor fuel assembly structure; a grid spring or maintenance system, or a screw; an element of cooling circuits of a nuclear reactor; a pipe or a pin for cluster guide, or a spring guide or a heat exchanger, or a screw or bolt, or any other component of Ni-based alloys contacting with the fluid; a semi finished-product from which the parts are optionally prepared by a forming, machining or cutting process; or a sheet, strip or a wire, or a bar or a draft. #CMT#EXAMPLE : #/CMT# No suitable example given. |
