Nippon Steel Nisshin Co., Ltd.

Nisshin Steel Co., Ltd.

Tomokazu Nobutoki

Takefumi Nakako

Kazuaki Hosomi

Hiroshi Asada

A welded member includes a hot dip Zn-based alloy coated steel sheet as a base material and has excellent corrosion resistance and weld bead shear strength. In the welded member in which a lower sheet and an upper sheet, which are hot dip Zn-based alloy coated steel sheets, are stacked and arc-welded together, a weld bead is formed so that a cross-sectional width W satisfies the following formula 2T&#x2264;W&#x2264;6T, and a blowhole occupancy Br represented by the following formula becomes not more than 50%: Br=(&#x3a3;di/L)&#xd7;100, where T represents a thickness of the hot dip Zn-based alloy coated steel sheet, di represents a length of an i-th blowhole observed in X-ray radiography, and L represents a length of the weld bead.

Welded member and method for manufacturing same

Hot dip Zn-based alloy coated steel sheets (') are arc-weld in such a way that (a) a current waveform is a pulsed current waveform in which (i) a peak current and a base current alternate with each other at a pulse period of 1 ms to 50 ms and (ii) an average welding current is 100 A to 350 A and (b) an average welding voltage is 20 V to 35 V. Each of the hot dip Zn-based alloy coated steel sheets (&#x2032;) includes a coating layer that contains Zn as a main component and that contains Al at a concentration of 1.0% by mass to 22.0% by mass, and has a coating weight W of 15 g/mto 250 g/m.

Arc welding method for hot-dip galvanized steel plate having excellent appearance of welded part and high welding strength, method for manufacturing welding member, and welding member

The present invention provides a method for producing a TIG-welded stainless steel tube without adding Hto a shielding gas, while inhibiting generation of a weld defect. The method is a method for producing a TIG-welded stainless steel tube and includes the steps of bending a stainless steel strip in a width direction so as to butt both edges against each other and TIG-welding the both edges thus butted. A pulse waveform of a pulse frequency of 40 Hz to 300 Hz is used as a current waveform of a welding power source.

Method for producing TIG welded stainless steel tube, TIG welded stainless steel tube, and TIG welded stainless member

Provided are: an arc welding method that suppresses occurrences of blow holes in initial parts and final parts in a Zn plated steel sheet and reduces the occupancy ratio for blow holes in the welded part as a whole; and a welded joint.

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Tokyo, Japan

Tomokazu Nobutoki