Abstract: A combustion line, having a combustion liner body and rings welded inside the liner body, is fabricated by enlarging the diameter of each ring so that the spacing between the outer pheripheral surface of the ring and the inner peripheral surface of the liner body may fall within a predetermined range. Subsequently tacking the ring and the liner body by lap resistance welding in the state in which the diameter of the ring has been enlarged; thereafter, brazing the rings and the liner body which have been tacked.

Abstract: A method of connecting superconducting wires have the steps of preparing a connecting superconducting wire piece, exposing the filaments of the superconducting layers to be connected and the filaments of the connecting superconducting wire piece by partially dissolving and removing the coating layers, inserting the filaments of the superconducting wires to be connected into the filaments of the connecting superconducting wire piece such that the filaments of the connecting superconducting wire piece cross and envelope the filaments of the superconducting wires to be connected, fitting a metallic connecting pipe on the region where the filaments cross each other, and crimping the metallic connecting pipe onto the crossing filaments thereby tightly fixing and connecting the exposed filaments to each other.

Abstract: A rotor shaft for steam turbines has a journal portion to be supported by a bearing. The journal portion is provided with a sleeve for a bearing made of an alloy of bainite structure comprising 0.04 to 0.35% C, 0.2 to 2% Mn, less than 1% Si, 0.5 to 3% Cr, less than 5% Ni, and less than 0.5% V, having yield strength of more than 50 kg/mm.sup.2 and Lt of less than 24. The sleeve is divided into two semicylindrical segments, and they are arranged on a small diameter portion of the shaft adjacent to said journal portion, welded into one piece, and subjected to stress relief treatment at a temperature higher than a temperature of tempering conducted to the sleeve before welding. The welded sleeve is fitted on the journal portion by shrink-fit so that the sleeve can be served as a superior bearing.

Abstract: A vacuum chamber for welding in which to place a workpiece is hermetically connected to a vacuum chamber for an electron beam gun in which to place an electron beam gun, and the former is kept at a vacuum of 1.times.10.sup.-4 Torr while the latter, at a vacuum of 1.times.10.sup.-6 Torr. The distance between the electron beam gun and the surface of the workpiece is made greater than the mean free path of gas molecules and metal vapor molecules generated in treating, e.g., 1.85 m. Two focusing coils are arranged to prevent the expansion of the electron beams.

Abstract: An electron beam welding machine comprises an electron gun including a first beam adjusting means, a second beam adjusting means disposed spaced from the first beam adjusting means so as to be movable in the direction of an electron beam path, and position adjusting means for adjusting the position of the second beam adjusting means through rotary movement about an axis perpendicularly crossing the electron beam path and linear movements on a plane perpendicular to the electron beam path. The machine further includes a mirror and light source mounted on the electron gun to emit light on the electron beam path, and photodetectors mounted on the opposite sides of the second beam adjusting means so as to face the electron gun and a workpiece, whereby the correct position of the second beam adjusting means is detected.

Abstract: An electron beam welding apparatus is provided with a magnetic shielding pipe for preventing electron beams emitted from being deflected by stray magnetic fields, and a removing device for removing metal deposit accumulated on a tip portion of the magnetic shielding pipe, which tip portion faces to a weld formed by welding of materials to be welded. The removing device is provided with at least a pair of shutters which move along a tip face of the tip portion to prevent the metal deposit from accumulating on the tip portion. The pair of shutters provides in their central portion a hole for passing electron beams therethrough when they are closed so that welding can continue irrespectively of the movement of the shutters.