Abstract: An upper plate is arranged on the top surface of a lower vertical plate to form a T-type joint, and a penetration promoter is applied on the surface of the upper plate of the T-type joint. Subsequently, when performing non-consumable electrode arc welding, a penetration width w of a molten pool on the side of the vertical plate after penetrating through the back side of the vertical plate is formed equal to or greater than the vertical plate thickness if a lower vertical plate thickness is the same thickness as an upper plate thickness or thinner than the upper plate thickness, and the penetration width of the molten pool is formed equal to or greater than the upper plate thickness if the lower vertical plate thickness is thicker than the upper plate thickness, thereby forming a penetration shape having a desired welding metal part.

Abstract: The present invention has an object to reduce residual stress in a tensile direction of a weld on the inner side in contact with reactor water of austenitic stainless steel piping, and to change the residual stress into compressive stress, to reduce stress corrosive cracking. The present invention provides a welding process for stainless steel piping of laminating two types of welding wire made of different materials in a groove of austenitic stainless steel piping, including at least one of a first layer penetration welding step of performing a predetermined back bead width on the back side of the groove bottom and a tack welding step, a first lamination welding step of lamination welding of austenitic stainless steel wire from the bottom to the top of the groove, and a second lamination welding step of lamination welding of nickel-base alloy wire to a final layer at the top of the groove.

Abstract: Provided are an underwater processing apparatus which can effectively prevent water from entering a shield for a workpiece having a surface ruggedness, and in which variation in a gas flow for a processing part is reduced, a processing method and an application thereof to a nuclear reactor, and the under water processing device is composed of a shield means which locally cover the processing part with the gas in order to prevent water from entering the shield member, the shield means having a solid wall formed of a member which is slidable in a part where it make contact with the workpiece, and adapted to make contact with the workpiece and to be moved up and down by a pressing force, and a water jetting means for forming a water curtain around the outer periphery of the solid wall.

Abstract: A Mg alloy member with an anticorrosive coating free from any environmental load can be produced by using a solution for chemical conversion treatment for anticorrosive coating, which comprises 0.05 to 1 mol/l of an oxoacid compound of heavy metal selected from Mo, W and V and has a pH of 2 to 6 adjusted by sulfuric acid or nitric acid, and is characterized by contacting the surface of Mg alloy preferably containing 2 to 10% Al with the solution, thereby forming a specific oxide film and, if necessary further forming a fluorine-containing organic film on the film, the resulting Mg alloy member being used in electrically driven blowers, note-type personal computers, various household electrical appliances, etc.

Abstract: A Mg alloy member with an anticorrosive coating free from any enviromental load can be produced by using a solution for chemical conversion treatment for anticorrosive coating, which comprises 0.05 to 1 mol/l of an oxoacid compound of heavy metal selected from Mo, W and V and has a pH of 2 to 6 adjusted by sulfuric acid or nitric acid, and is characterized by contacting the surface of Mg alloy preferably containing 2 to 10% Al with the solution, thereby forming a specific oxide film and, if necessary further forming a fluorine-containing organic film on the film, the resulting Mg alloy member being used in electrically driven blowers, note-type personal computers, various household electrical appliances, etc.

Abstract: Reduction of air resistance which acts on the conventional motor-driven blower is limited because crushed protrusions are formed on the surface of the plate of the impeller of the conventional motor-driven blower, and this air resistance is a significant impediment to an increase of the operating speed of the motor-driven blower. Thus, an impeller is provided which comprises a front plate having a suction opening, a back plate disposed opposite to the front plate, and a plurality of blades disposed between the front plate and the back plate. At least either the front plate or the back plate is formed integrally with the blades.