Abstract: A heat exchanger including: a heat exchanger main body forming a flow path through which a fluid circulates; heat transfer tubes arranged side by side so as to extend in an extending direction of the flow path; and a baffle plate group having a plurality of baffle plates provided with gaps therebetween in the extending direction of the flow path while supporting the heat transfer tubes. The baffle plates are provided so as to each occupy only a portion of the flow path cross section when viewed from the extending direction of the flow path, and the baffle plates of the baffle plate group are provided such that at least a portion of mutually occupied areas do not overlap, and that the entire area of the flow path cross section is occupied by combining the mutually occupied areas, as seen from the extending direction of the flow path.

Abstract: A method for manufacturing a machine component includes a process of estimating post-heat-treatment strength for the intermediate form of a base material after a certain mechanical working process is performed, and a process of comparing the estimated strength with reference strength required for a final form. According to a result of the comparison, heat treatment of the base material is performed after one of the mechanical working processes is performed.

Abstract: A heat treatment method of an impeller includes a heat treatment preparation process of arranging the impeller within a vacuum furnace, an impeller covering process of covering an outer peripheral surface of the impeller in a circumferential direction by a heat uniformizing jig made of a radiation conversion material which radiates transferred heat as radiant heat, and a heat treatment process including a heating process and a cooling process in which heat treatment is performed by heating or cooling the impeller covered with the heat uniformizing jig from the periphery using a heater.

Abstract: A heat treatment method of an impeller includes a heat treatment preparation process of arranging the impeller within a vacuum furnace, an impeller covering process of covering an outer peripheral surface of the impeller in a circumferential direction by a heat uniformizing jig made of a radiation conversion material which radiates transferred heat as radiant heat, and a heat treatment process including a heating process and a cooling process in which heat treatment is performed by heating or cooling the impeller covered with the heat uniformizing jig from the periphery using a heater.

Abstract: A method for manufacturing a machine component includes a process of estimating post-heat-treatment strength for the intermediate form of a base material after a certain mechanical working process is performed, and a process of comparing the estimated strength with reference strength required for a final form. According to a result of the comparison, heat treatment of the base material is performed after one of the mechanical working processes is performed.