Kabushiki Kaisha Kobe Seiko Sho

Kobe Steel, Ltd.

Fusaki Koshiishi

Tsuyoshi Kurokawa

Hiroyuki Shimizu

Takaaki Ito

Kei Yamazaki

Kazuhiko Ito

Yasuyuki Yokota

Tetsuo Suga

Isao Aida

Keiichi Suzuki

Masahiro Honma

Hajime Uchiyama

A pulsed arc welding method using carbon dioxide gas alone or a mixed gas made mainly of carbon dioxide gas as a shield gas, provides a pulse current of alternately repeating first and second pulses as a weld current. The first pulse and the second pulse have a pulse waveform of a different pulse peak current level and a different pulse width, respectively, and the following conditions are satisfied: peak current of the first pulse (I1)=300 to 700 A; peak period (T1)=0.3 to 5.0 ms; base current I1=30 to 200 A, base period (T1)=0.3 to 10 ms; peak current of the second pulse (I2)=200 to 600 A; peak period (T2)=1.0 to 15 ms; base current (I2)=30 to 200 A; and base period (T2)=3.0 to 20 ms.

Pulsed arc welding method

A plating-free solid wire for arc welding has pits opening on its circumference, and wider inside than at each opening, and/or pits having a portion non-irradiated with an externally incoming light. A sulfide and a polyisobutene-containing oil are present in the pits and/or on the wire surface, the latter being present in an amount of 0.1-2 g/10 kg of wire. Twenty or more pits are present in total per and along wire circumference. The effective pit length ratio is 0.5% inclusive-50% exclusive. 0.1-2 g of the oil is present per 10 kg of wire. 0.01-0.5 g/10 kg of 0.1-10-&mgr;m-particle-dia MoS is present in &ldquo;bottleneck-like and/or cave-like pits&rdquo;, on the wire surface or immediately under the wire surface. A 2-10 mass ppm/total wire mass of K compound in K is present in the pits and/or on the wire surface. These ensure good feedability and lubricating properties, and less spatters.

Plating-free solid wire for MAG welding

Realized is a welding wire containing flux used for a gas shielded arc welding of a direct current/positive polarity mode, with use of which a quantity of sputter generated is small, a good weldability is realized and a weld metal with an excellent toughness is obtained in all the welding positions under application of a welding current in the range of a low current to a medium current, or in a definite manner in the range of 50 to 300 A. The flux contains 0.7 to 3 wt % Al, 0.1 to 1.0 wt % Mg and 1.2 to 5 wt % BaF , each content being a value in wt % to a total weight of the wire and the sum of a content of Al plus a content of Mg multiplied by 3 being in the range of 1.3 to 5 wt %, a filling ratio of the flux to the total weight of the wire is in the range of 5 to 30 wt %, a total Mn content in a steel sheath and the flux combined is in the range of 0.2 to 1.9 wt % and a total Si content in the steel sheath and the flux combined in the range of 0.001 to 0.9 wt %.

Gas shielded arc welding flux cored wire

Described is a solid wire for MAG welding which has no copper plating on the wire surface and which has good welding workabilities such as a reduced amount of generated spatters and good arc stability in the MAG welding of steel sheets. A solid wire for MAG welding comprises, as chemical components for the wire, 0.01 to 0.15 wt % of C, 0.20 to 1.00 wt % of Si, 0.70 to 1.70 wt % of Mn, 0.30 wt % or below of Ti, 0.025 wt % or below of S, 0.020 wt % or below of O, and the balance being Fe and inevitable impurities, wherein said wire is applied on the surface thereof with at least one compound serving as an arc stabilizer and selected from the group consisting of a K compound and a Cs compound in such a way that when an amount of the K compound to be applied to (calculated as K) is taken as Appm relative to the weight of said wire and an amount of the Cs compound (calculated as Cs) is taken as Bppm, a value of (A+3B) is in the range of 2 to 15 ppm. The wire has such a structure as not to be plated with copper on the surface thereof.

Solid wire for mag welding

Growing community of inventors

Fujisawa, Japan

Fusaki Koshiishi