Abstract: Provided is a glass composition including the following components in mass %: 45?SiO2?80; 10?B2O3?40; 0.1?Al2O3?20; 0.1?(MgO+CaO)?10; 0?(Li2O+Na2O+K2O)?5; and 0.1?T-SnO2?2, where T-SnO2 represents total tin oxide calculated as SnO2, wherein 0?MgO/(MgO+CaO)?0.50 is satisfied on a mass basis. This glass composition is suitable for stably manufacturing a low-permittivity glass fiber.

Abstract: Second member 20 includes a material that is difficult to weld to first member 10. In first member 10, recess 11 is formed by press molding such that a lower surface of first member 10 opposite to second member 20 protrudes. Third member 30 is arc-welded toward at least a bottom of recess 11 via penetrating part 21 of second member 20. Second member 20 is compressed by flange 31 and first member 10 by solidification contraction of third member 30, and second member 20 is therefore fixed between flange 31 of third member 30 and first member 10.

Abstract: A welding tip includes a tip body having a wire insertion bore along a central axis and a leaf spring configured to press a welding wire onto a feeding point disposed on an inner surface of the wire insertion bore. The tip body 1a has an aperture on an outer circumferential surface on the distal end side. The leaf spring has a first end that is a free end disposed on the distal end side of the tip body and a second end fixed to the tip body. The aperture includes a first aperture accommodating the leaf spring and second apertures disposed in communication with the first aperture and configured to discharge wear particles created during welding to the outside.

Abstract: A pulse arc welding device is controlled so as to alternately repeat a peak current period in which a welding current is a peak current and a base current period in which the welding current is a base current smaller than the peak current, feed a welding wire to an object at a feeding speed while the welding current flows through the welding wire, generate an arc between the welding wire and the object, and weld the object. So as to keep an arc length of the arc to be constant, in the base current period, the feeding speed is set to a first feeding speed and, in the peak current period, the feeding speed is set to a second feeding speed which is larger than the first feeding speed and corresponds to the first feeding speed. By this method, good welding quality with reduced spattering and suppressed undercut can be obtained.

Abstract: A first member and a second member are formed of metal materials of the same type and a third member is formed of a material of a different type that is difficult to weld to the first member and the second member. The first member and the second member are welded to each other via a through hole with the third member interposed therebetween in a region corresponding to a first protrusion. For the first member and the third member, and the second member and the third member, each of respective outer peripheral portions of an overlapping portion of the first member and the third member and an overlapping portion of and the second member and the third member is welded.

Abstract: A joint structure includes a first material (1), a second material (2) weldable to the first material, and a third material (3) at least a portion of which being sandwiched between the first material and the second material, having a through opening portion at the sandwiched portion, and including a material that is difficult to be welded to both the first material and the second material, the first material and the second material welded the via through opening portion. At least one of the first material and the second material is provided with a protrusion (14) inserted in the through opening portion. A first gap (4) is provided between an inner peripheral surface of the through opening portion and the protrusion. A second gap (5) is provided between the first material and the second material, the second gap having a size depending on a plate thickness of the first material in a region corresponding to the protrusion. Under a condition in which the second gap has a size of greater than or equal to 0.

Abstract: A second member is made of a material difficult to be welded to a first member. A first step includes forming a third member by welding a first filler material to the first member through a through-portion of the second member. A second step includes forming a fourth member by covering a surface of the third member with a second filler material and welding the fourth member to the second member.

Abstract: DC arc welding is performed by alternating a short-circuit period and an arc period. The arc period includes first to fourth periods. A welding current is raised to a first current value in the first period, lowered to a second current value with a time slope in the second period, kept at the second current value in the third period, and raised to a third current value then kept at the value in the fourth period. A wire feeding speed is constant throughout the short-circuit period and the arc period. In the second period, a welding output is under constant voltage control. In the third period and the fourth period, the welding output is under constant current control of the welding output.

Abstract: A junction structure includes a first material that is a metallic material, a third material that is a metallic material and is weldable to the first material, and a second material which is a nonferrous metallic material or a nonmetallic material. The second material is sandwiched and fixed between the first material and the third material by lap joining. At least one of the first material or the third material has a weld zone where the first material and the third material are melted and joined together, and at least one exhaust groove or at least one exhaust hole around the weld zone. The at least one exhaust groove or the at least one exhaust hole penetrates a thickness of the at least one of the first material or the third material.

Abstract: A junction structure includes a first metallic material, a second material different in type from the first metallic material, and a welding wire as a third material similar to the first metallic material. The second material is stacked on the first material. The molten metal of the third metallic material is deposited by arc welding into the through part of the second material so as to form a flanged or tapered bead, so that the first and third metallic materials and the second material are fixed together.

Abstract: Provided is an arc welding control method for performing control in an arc period, the control including: first control of increasing welding current (Ia) to first current value (I1) in a range from 200 A to 300 A inclusive at first gradient (S1) and maintaining welding current (Ia) at first current value (I1) for first period (T1); second control of reducing welding current (Ia) from first current value (I1) to second current value (I2) at second gradient (S2) and maintaining welding current (Ia) at second current value (I2) for second period (T2); third control of increasing welding current (Ia) from second current value (I2) to third current value (I3) higher than first current value (I1) at third gradient (S3); and fourth control that is started to reduce welding current (Ia) from third current value (I3) within 0.5 ms after welding current (Ia) reaches third current value (I3) under the third control.

Abstract: A joint structure includes: a first same-type metal member; a second same-type metal member that can be mutually welded with the first same-type metal member; and a different-type member that has a penetrating portion, is interposed between the first same-type metal member and the second same-type metal member. In the plate thickness direction of an emission region in which a laser beam is emitted toward the penetrating portion, the plate thickness at the emission region of the first same-type metal member positioned on the side on which the laser beam is emitted is a predetermined thickness corresponding to a first gap. The first same-type metal member and the second same-type metal member are fused and bonded together via the penetrating portion, and the different-type member is compressed and fixed, such that the different-type member is fixed to the first same-type metal member and the second same-type metal member.

Abstract: A second member has a through-portion penetrating toward a first member. An overlapped surface of the second member with the first member includes a recess. The recess is recessed so as to surround an entire periphery of the through-portion. A sealing material is injected into the recess from an injection hole to close a gap between overlapped surfaces of the first member and the second member.

Abstract: A second member has a through-portion penetrating toward a first member. An overlapped surface of the second member with the first member includes a recess. The recess is recessed so as to surround an entire periphery of the through-portion. The recess is provided with a sealing material. The sealing material closes a gap between overlapped surfaces of the first member and the second member.

Abstract: An arc welding method alternately generates a short-circuit state and an arc state. In the method, short circuits are generated also in the arc period. This more than doubles the total number of short circuits, which is the sum of the short circuits generated in the short circuit period and those generated in the arc period. This enables a thin plate to be arc welded at a higher speed, while reducing its burn-through.

Abstract: A method of controlling arc welding with a consumable electrode includes repeating the following periods in sequence: a short-circuit welding period to perform short-circuit arc welding; a pulse welding period to perform pulse welding; and a cooling period in which the welding current output is zero.

Abstract: Disclosed is an arc welding control method of controlling a welding current in short-circuit arc welding of feeding a welding wire toward a base metal and alternating a short-circuit state and an arc state. The arc welding control method includes: executing, in the short-circuit state, a first increase in the welding current with a first slope, a first decrease in the welding current to a first bottom value after executing the first increase, a second increase in the welding current with a second slope after executing the first decrease, and a second decrease in the welding current to a second bottom value that is smaller than the first bottom value after executing the second increase to shift a state to the arc state.

Abstract: Arc welding, in which a welding wire serving as a consumable electrode is fed toward a base material and a welding current alternately including a peak current and a base current is caused to flow through the welding wire and the base material, is performed such that after a short-circuit between the welding wire and the base material is detected, a feeding speed of the welding wire is changed from a first feeding speed to a second feeding speed that is on a negative side from the first feeding speed when a speed in a direction in which the welding wire is fed toward the base material is defined as positive.

Abstract: Provided is an arc welding device that performs welding by alternately repeating a short-circuit period provided with a short-circuit state in which a welding wire and a base material are short-circuited, and an arc period provided with an arc state in which an arc is generated between the welding wire and the base material. A calculation unit calculates an integrated power value by integrating power supplied to the welding wire within a predetermined period, after the welding wire is short-circuited. A controller reduces a welding current to be supplied to welding wire when the integrated power value is larger than a predetermined threshold.

Abstract: In arc welding in which a welding wire serving as a consumable electrode is fed toward a base material and a welding current is caused to flow through the welding wire and the base material to alternately repeat a reverse polarity period and a positive polarity period, after a short circuit between the welding wire and the base material is detected, a feeding speed of the welding wire is changed from a first feeding speed to a second feeding speed on a negative side of the first feeding speed when a speed in a direction toward the base material is defined as positive.