Abstract: A gas-shielded arc welding method includes welding a steel plate having a tensile strength of 780 MPa or more while feeding a consumable electrode via a welding torch and flowing a shielding gas. The consumable electrode includes, in mass %, C: 0 to 0.20%, Si: 0 to 0.50%, Mn: 0 to 0.50%, Cr: 1.00% to 9.00%, S: 0.0020% to 0.0600%, and Ni: 0 to 0.50%. The shielding gas includes, in vol. %, at least one of CO2 and O2: 1% to 15% in total, with the remainder being Ar and unavoidable impurities. Welding is performed under the condition satisfying the relationship of 1?{?0.05×[CO2+O2]}+[Cr]?8.3, and [Cr] represents the content of Cr in the consumable electrode, and [CO2+O2] represents a total content of at least one of CO2 and O2 in the shielding gas.

Abstract: A welding system includes a welding torch that welds a workpiece by using a wire, a suction device that sucks shielding gas, and a sucked shielding gas supply path for allowing the sucked shielding gas to flow, wherein the welding torch includes a contact chip that guides the wire, a shielding gas supply nozzle that supplies the shielding gas to a weld zone, and a suction nozzle that surrounds a periphery of the wire protruding from the contact chip, and is opened toward a tip of the wire to suck the shielding gas.

Abstract: A gas-shielded arc welding method includes feeding a consumable electrode via a welding torch and performing welding while flowing a shielding gas. The welding torch includes a nozzle. An inner diameter of the nozzle is 15 mm or more. A nozzle-base material distance between a tip of the nozzle and a material to be welded is 22 mm or less. A ratio expressed by (the inner diameter of the nozzle/the nozzle-base material distance) is 0.7 or more and 1.9 or less.

Abstract: The present invention pertains to: a method for arc spot welding a steel plate having a carbon equivalent CeqBM of 0.35 or more (the carbon equivalent CeqBM is defined in the specification), the method being characterized in that a welding wire containing 98.5 mass % or more of Fe is used, and the ratio between the carbon equivalent CeqWM of a weld metal formed by the method (the carbon equivalent CeqWM of the weld metal is defined in the specification) and the carbon equivalent CeqBM of the steel plate, CeqWM/CeqBM is 0.2-1.0. According to the arc spot welding method, brittle fracture can be prevented and high joint strength can be obtained even when the C content in the steel plate is high.

Abstract: The purpose of the present invention is to provide a flux cored wire which has good high-temperature cracking resistance, and which enables the achievement of a welded part exhibiting excellent coating adhesion. The present invention relates to a metal flux cored wire for gas-shielded are welding, which contains, relative to the total mass of the wire, 0.02-0.30% by mass of C, 0.3-1.5% by mass of Si, 0.3-2.5% by mass of Mn, and oxide of at least one element selected from the group consisting of Si, Cr and Ni in an amount of 0.01-0.30% by mass in total, 0.020% by mass or less of S, and 0.3% by mass or less of Al, Ca, Mg, K and Na in total in the form of metals or alloys, with the balance made up of Fe and unavoidable impurities.

Abstract: A method for welding a galvanized steel sheet includes utilizing a pulse welding of repeatedly applying a pulse peak current and a base current, setting a welding speed to 100 cm/min or less, and using a shielding gas in which 1 vol % or more and 10 vol % or less of at least either one of CO2 and O2 is added to Ar. The pulse peak current has a pulse peak time being in a range of 7% or more and less than 50% of one period depending on a sheet thickness of the galvanized steel sheet.

Abstract: The present invention relates to a method for arc-welding a steel plate having a C content of 0.08-0.30% by mass, wherein the arc welding method comprises welding under a condition whereby X represented by formula (1) is 200 or less using a welding wire in which the total content of Cr and Ni thereof is 1.00% by mass or greater. (1): X=0.8×(300-279[C]W-25[Si]W-35[Mn]W-49[Ni]W-47[Cr]W-61[Mo]W) +0.2×(300-279[C]BM-25[Si]BM-35[Mn]BM-49[Ni]BM-47[Cr]BM-61[Mo]BM) (where [C]W, [Si]W, [Mn]W, [Ni]W, [Cr]W, [Mo]W, [C]BM, [Si]BM, [Mn]BM, [Ni]BM, [Cr]BM, and [Mo]BM are defined in the specification).

Abstract: The present invention pertains to: a method for arc spot welding a steel plate having a carbon equivalent CeqBM of 0.35 or more (the carbon equivalent CeqBM is defined in the specification) and containing 0.35 mass % or more of C, the method being characterized by forming a weld metal having a structure in which the proportion of an austenitic structure exceeds 80%; and a welding wire suitable for being used therefor. According to the arc spot welding method, brittle fracture can be prevented and high joint strength can be obtained even when the C content in the steel plate is high.

Abstract: A gas-shielded arc welding method includes welding a steel plate having a tensile strength of 780 MPa or more while feeding a consumable electrode via a welding torch and flowing a shielding gas. The consumable electrode includes, in mass %, C: 0 to 0.20%, Si: 0 to 0.50%, Mn: 0 to 0.50%, Cr: 1.00% to 9.00%, S: 0.0020% to 0.0600%, and Ni: 0 to 0.50%. The shielding gas includes, in vol. %, at least one of CO2 and O2: 1% to 15% in total, with the remainder being Ar and unavoidable impurities. Welding is performed under the condition satisfying the relationship of 1?{?0.05×[CO2+O2]}+[Cr]?8.3, and [Cr] represents the content of Cr in the consumable electrode, and [CO2+O2] represents a total content of at least one of CO2 and O2 in the shielding gas.

Abstract: A method for welding a galvanized steel sheet includes utilizing a pulse welding of repeatedly applying a pulse peak current and a base current, setting a welding speed to 100 cm/min or less, and using a shielding gas in which 1 vol % or more and 10 vol % or less of at least either one of CO2 and O2 is added to Ar. The pulse peak current has a pulse peak time being in a range of 7% or more and less than 50% of one period depending on a sheet thickness of the galvanized steel sheet.

Abstract: A gas-shielded arc welding method includes feeding a consumable electrode via a welding torch and performing welding while flowing a shielding gas. The welding torch includes a nozzle. An inner diameter of the nozzle is 15 mm or more. A nozzle-base material distance between a tip of the nozzle and a material to be welded is 22 mm or less. A ratio expressed by (the inner diameter of the nozzle/the nozzle-base material distance) is 0.7 or more and 1.9 or less.

Abstract: The present invention provides the following: a covered flux which has a low chromium content and which can improve the fatigue strength of a weld in additional welding; and a covered electrode. The covered flux used for a covered electrode has a composition that contains, relative to the total mass of the covered flux, 35-55 mass % of a metal carbonate (in terms of CO2), 10-30 mass % of a metal fluoride (in terms of F), and 8.5-20 mass % of Mn and/or 7.5-20 mass % of Ni. In addition, the covered electrode is obtained by coating an iron-based core wire with this covered flux.

Abstract: The purpose of the present invention is to provide a flux cored wire which has good high-temperature cracking resistance, and which enables the achievement of a welded part exhibiting excellent coating adhesion. The present invention relates to a metal flux cored wire for gas-shielded are welding, which contains, relative to the total mass of the wire, 0.02-0.30% by mass of C, 0.3-1.5% by mass of Si, 0.3-2.5% by mass of Mn, and oxide of at least one element selected from the group consisting of Si, Cr and Ni in an amount of 0.01-0.30% by mass in total, 0.020% by mass or less of S, and 0.3% by mass or less of Al, Ca, Mg, K and Na in total in the form of metals or alloys, with the balance made up of Fe and unavoidable impurities.

Abstract: A welding system includes a welding torch that welds a workpiece by using a wire, a suction device that sucks shielding gas, and a sucked shielding gas supply path for allowing the sucked shielding gas to flow, wherein the welding torch includes a contact chip that guides the wire, a shielding gas supply nozzle that supplies the shielding gas to a weld zone, and a suction nozzle that surrounds a periphery of the wire protruding from the contact chip, and is opened toward a tip of the wire to suck the shielding gas.

Abstract: Provided is a flux-cored wire which can be MIG-welded at any welding position using a pure Ar gas as a shielding gas. A flux-cored wire having a flux filled in the outer skin thereof, wherein TiO2, Al2O3, SiO2 and ZrO2 are contained in amounts of 4.7 to 8.5% by mass, 0.5 to 3.5% by mass, 0.5 to 2.0% by mass and 0.8 to 3.0% by mass, respectively, and metal oxides are also contained in the total amount of 8.0 to 13.5% by mass all relative to the total mass of the wire, and the amount of a metal fluoride is limited to 0.02% by mass or less (including 0% by mass).

Abstract: There is provided a flux-cored wire containing flux within a stainless steel or mild steel outer cover for use in stainless steel welding and gas-shielded arc welding using a shielding gas. The flux-cored wire contains, based on the total mass of the flux-cored wire, predetermined amounts of C, Si, Mn, P, S, Cr, Ti, and O. The remainder are Fe and incidental impurities. The shielding gas is pure Ar gas.

Abstract: Provided is a flux-cored wire that is for build-up welding, can obtain a target welding metal composition by means of a low number of layers, and has a low base material dilution. The flux-cored wire for build-up welding, which is such that flux fills the inside of an outer skin, has a composition satisfying the belowmentioned formula (I) when, with respect to the total mass of the flux, the total content (F equivalent value) of alkali metal fluorides and alkaline earth metal fluorides is A (mass %), the total content of alkali metal elemental metals and alkaline earth metal elemental metals is B (mass %), and the total content of alkali metal oxides and alkaline earth metal oxides is C (mass %): 0.3?[A/{1+0.7×(B+2C)}]?2.0??(I).

Abstract: A parallel scanning circuit outputs a parallel scanning signal for making forward and backward scanning lines parallel. A vertical correlation detection circuit detects a portion where the change in luminance in the vertical direction exceeds a predetermined value on the basis of a luminance signal, and outputs a movement control signal representing the distance of movement on the screen of the scanning line. A retrace period reversion circuit reverses the lime axis of the movement control signal in a retrace period. A clamping circuit clamps the movement control signal to a predetermined DC voltage at the timing of horizontal synchronizing signal. A synthesizing circuit synthesizes the parallel scanning signal and the movement control signal, and feeds a synthesized signal as a vertical velocity modulation signal to a vertical velocity modulation coil.

Abstract: A video signal of an interlaced scanning system having 525 scanning lines and a vertical scanning frequency of 60 Hz is converted to a video signal having 1050 scanning lines and a vertical scanning frequency of 120 Hz, for displaying an image by bidirectional scanning. A vertical synchronizing signal is subjected to offset processing by a ¼ horizontal scanning period when an odd field is started, thereby keeping interlaced relation between odd and even fields. The vertical synchronizing signal is subjected to offset processing by a ½ horizontal scanning period every frame, so that the scanning direction for each scanning line is reversed every frame.

Abstract: A video signal converter converts a video signal to a required form. The required form of the signal is the display format for displaying the signal. The input signal is converted to a digital signal and stored in a memory using the output of a first clock pulse generator synchronized to the horizontal synchronizing signal of the input signal. The digital signal is read out from the memory using the output of a second clock pulse generator synchronized to the vertical synchronizing signal of the input signal from a position specified by the controller. The output digital signal is then reconverted to an analog signal.