Abstract: A repair welding method according to at least one embodiment is for a member in which a first end and a second end of a parent material are connected by welding and includes: a step of removing a portion including at least a part of a first heat-affected zone of an existing welded portion of the member; and a step of performing repair welding after removing the portion. In a cross-section including the parent material and the existing welded portion, all intersection portions between the first heat-affected zone of the existing welded portion and a second heat-affected zone due to the repair welding have an intersection angle between the first heat-affected zone and the second heat-affected zone of 70° to 110°.

Abstract: A repair welding method according to at least one embodiment is for a member in which a first end and a second end of a parent material are connected by welding and includes: a step of removing a portion including at least a part of a first heat-affected zone of an existing welded portion of the member; and a step of performing repair welding after removing the portion. In a cross-section including the parent material and the existing welded portion, all intersection portions between the first heat-affected zone of the existing welded portion and a second heat-affected zone due to the repair welding have an intersection angle between the first heat-affected zone and the second heat-affected zone of 70° to 110°.

Abstract: Bolt holes 16 are formed in a joint part 14 of a turbine housing 12, with flanged bolts 40 screwed in the bolt holes 16. A flange part 32 of a bearing housing 30 is sandwiched between bearing surfaces 44a of the flanged bolts 40 and an inner end face 14b of the joint part 14. A sealing ring 48 is interposed in an annular space s. Before the flanged bolts 40 are fastened, there is formed a height difference G equivalent to a compression allowance h for the sealing ring 48, between an outer end face 60a of the joint part 14 and a bolt receiving surface 32a of the flange part 32. The flanged bolts 40 are screwed into the bolt holes 16 until the bearing surfaces 44a make tight contact with the outer end face 60a so as to resiliently deform the sealing ring 48.

Abstract: Bolt holes 16 are formed in a joint part 14 of a turbine housing 12, with flanged bolts 40 screwed in the bolt holes 16. A flange part 32 of a bearing housing 30 is sandwiched between bearing surfaces 44a of the flanged bolts 40 and an inner end face 14b of the joint part 14. A sealing ring 48 is interposed in an annular space s. Before the flanged bolts 40 are fastened, there is formed a height difference G equivalent to a compression allowance h for the sealing ring 48, between an outer end face 60a of the joint part 14 and a bolt receiving surface 32a of the flange part 32. The flanged bolts 40 are screwed into the bolt holes 16 until the bearing surfaces 44a make tight contact with the outer end face 60a so as to resiliently deform the sealing ring 48.

Abstract: A method of extending a life expectancy of a high-temperature piping, includes removing a heat insulation material which covers the piping having a high creep rupture risk, and lowering an outer surface temperature of piping, wherein a width of an exposed portion obtained is twice or more a distance from a peeled-off end portion of the exposed portion to a portion where a compressive stress is asymptotical to 0 after a change in stress between a tensile stress and the compressive stress occurring in the piping due to the removal of the heat insulation material is made from the tensile stress to the compressive stress, and the distance is calculated based on the following formulae, ?x=5, ? = 3 ? ( 1 - v 2 ) a 2 ? h 2 4 here, ? is a Poisson's ratio, a is an average radius of the piping, and h is a plate thickness of the piping.

Abstract: Bolt holes 16 are formed in a joint part 14 of a turbine housing 12, with flanged bolts 40 screwed in the bolt holes 16. A flange part 32 of a bearing housing 30 is sandwiched between bearing surfaces 44a of the flanged bolts 40 and an inner end face 14b of the joint part 14. A sealing ring 48 is interposed in an annular space s. Before the flanged bolts 40 are fastened, there is formed a height difference G equivalent to a compression allowance h for the sealing ring 48, between an outer end face 60a of the joint part 14 and a bolt receiving surface 32a of the flange part 32. The flanged bolts 40 are screwed into the bolt holes 16 until the bearing surfaces 44a make tight contact with the outer end face 60a so as to resiliently deform the sealing ring 48.

Abstract: A method of extending a life expectancy of a high-temperature piping, includes removing a heat insulation material which covers the piping having a high creep rupture risk, and lowering an outer surface temperature of piping, wherein a width of an exposed portion obtained is twice or more a distance from a peeled-off end portion of the exposed portion to a portion where a compressive stress is asymptotical to 0 after a change in stress between a tensile stress and the compressive stress occurring in the piping due to the removal of the heat insulation material is made from the tensile stress to the compressive stress, and the distance is calculated based on the following formulae, ?x=5, ? = 3 ? ( 1 - v 2 ) a 2 ? h 2 4 here, ? is a Poisson's ratio, a is an average radius of the piping, and h is a plate thickness of the piping.

Abstract: Bolt holes 16 are formed in a joint part 14 of a turbine housing 12, with flanged bolts 40 screwed in the bolt holes 16. A flange part 32 of a bearing housing 30 is sandwiched between bearing surfaces 44a of the flanged bolts 40 and an inner end face 14b of the joint part 14. A sealing ring 48 is interposed in an annular space s. Before the flanged bolts 40 are fastened, there is formed a height difference G equivalent to a compression allowance h for the sealing ring 48, between an outer end face 60a of the joint part 14 and a bolt receiving surface 32a of the flange part 32. The flanged bolts 40 are screwed into the bolt holes 16 until the bearing surfaces 44a make tight contact with the outer end face 60a so as to resiliently deform the sealing ring 48.

Abstract: In order to provide a welding structure of a tube header and tube stubs which successfully improves the durability thereof against creep and fatigue damage of the tube stubs without interposing a component of a different material between the tube header and the tube stubs, i.e. requiring additional components, a welding structure of the present invention comprises: a tube header (2) being made of ferritic heat resisting steel; a plurality of tube stubs (4) which are welded onto an outer surface of the tube header, each of the tube stubs having a bended section, in which the plurality of tube stubs (4) are made of austenite stainless steel, and welded to the tube header (2) by using nickel base alloy as a welding material.

Abstract: A damage evaluation method and apparatus of a metal material which is capable of determining whether a flaw in the metal sample is originated by the creep damage or in the manufacturing process, and also capable of estimating a remaining life of the metal component. The damage evaluation method of a metal material by the present invention is a method for evaluating a flaw in the metal sample comprising the steps of mounting onto a metal surface including an internal flaw and on both sides of the flaw a transmitting probe for transmitting an ultrasonic waves and a receiving probe for receiving the ultrasonic waves, transmitting the ultrasonic waves towards the internal flaw and receiving the diffracted wave from the flaw for determining whether or not a flaw is present in the metal, based on the analysis of the distribution of the diffracted waves and an analysis of the sample as to whether voids (creep voids) are present and, if present, the distribution of the voids.

Abstract: A damage evaluation method and apparatus of a metal material which is capable of determining whether a flaw in the metal sample is originated by the creep damage or in the manufacturing process, and also capable of estimating a remaining life of the metal component. The damage evaluation method of a metal material by the present invention is a method for evaluating a flaw in the metal sample comprising the steps of mounting onto a metal surface including an internal flaw and on both sides of the flaw a transmitting probe for transmitting an ultrasonic waves and a receiving probe for receiving the ultrasonic waves, transmitting the ultrasonic waves towards the internal flaw and receiving the diffracted wave from the flaw for determining whether or not a flaw is present in the metal, based on the analysis of the distribution of the diffracted waves and an analysis of the sample as to whether voids (creep voids) are present and, if present, the distribution of the voids.

Abstract: A damage evaluation method and apparatus of a metal material which is capable of determining whether a flaw in the metal sample is originated by the creep damage or in the manufacturing process, and also capable of estimating a remaining life of the metal component. The damage evaluation method of a metal material by the present invention is a method for evaluating a flaw in the metal sample comprising the steps of mounting onto a metal surface including an internal flaw and on both sides of the flaw a transmitting probe for transmitting an ultrasonic waves and a receiving probe for receiving the ultrasonic waves, transmitting the ultrasonic waves towards the internal flaw and receiving the diffracted wave from the flaw for determining whether or not a flaw is present in the metal, based on the analysis of the distribution of the diffracted waves and an analysis of the sample as to whether voids (creep voids) are present and, if present, the distribution of the voids.