Nippon Steel Corporation

Jeol Ltd.

Masahiro Matsuba

Shinji Kodama

Masafumi Azuma

Kenichiro Otsuka

Takuya Mitsunobu

Toyomitsu Nakamura

Yoichiro Mori

Masaaki Uranaka

Tasuku Zeniya

Shoko Oami

To further improve electrodeposition coating properties in a weld bead zone. A welded joint according to the present invention includes: a first steel sheet and a second steel sheet; and a weld bead zone formed by arc welding or laser welding, wherein at least one of the first steel sheet or the second steel sheet has a plating layer composed of a predetermined component and an oxide layer located on the plating layer in a non-heat-affected zone, and the weld bead zone has a weld metal and a slag layer formed on part of a surface of the weld metal, and the slag layer contains, by mass % when oxygen is excluded, Al: 1.0 to 45.0% and Mg: 1.0 to 30.0%, with the balance composed of Fe, easily oxidizable metallic elements, and impurities.

Welded joint

To more reliably suppress LME and blowhole formation while maintaining excellent corrosion resistance. A plated steel sheet according to the present invention, includes: a steel sheet as a base material; a plating layer located on at least part of a surface of the steel sheet; and an oxide layer located on a surface of the plating layer, where a chemical composition of the plating layer is made up of prescribed components, and Zn and impurities as the balance, and when a position at a depth of 5 nm from an uppermost surface of the oxide layer is observed by X-ray photoelectron spectroscopy (XPS), a value of an intensity ratio ([Al—O]+[Mg—O])/[Zn—O]) calculated from intensity of peaks respectively attributed to an Al—O bond, an Mg—O bond, and a Zn—O bond is 5.0 or more.

Plated steel sheet

An automobile undercarriage part of the present invention has a welded joint formed by base steel plate,

Automobile undercarriage part

An automobile undercarriage part of the present invention is an automobile undercarriage part including a welded joint in which a first steel sheet and a second steel sheet are overlapped and a fillet weld is formed between an end surface of the first steel sheet and a surface of the second steel sheet, in which a chemical composition of a weld metal that forms the welded joint contains, with respect to a total mass of the weld metal, by mass %, C: 0.02% to 0.20%, Si: more than 0% to less than 0.10%, Mn: 0.3% to 2.0%, Al: 0.002% to 0.30%. Ti: 0.005% to 0.30%, P: more than 0% to 0.015%, and S: more than 0% to 0.030%, and the following formula (1) and formula (2) are satisfied.[Al]+[Ti]>0.05  Formula (1)7×[Mn]−112×[Ti]−30×[Al]≤4.0  Formula (2)

The present invention provides a consumable electrode type gas shield arc welding method for performing arc welding of two steel sheets using a welding torch having a consumable electrode. The consumable electrode type gas shield arc welding method includes performing arc welding while a shielding gas having an oxygen potential &#x3b1; which is indicated by the following Expression (1) and ranges from 1.5% to 5% is supplied from the welding torch toward the consumable electrode, and blowing an oxidation promotion gas having an oxygen potential &#x3b2; which is indicated by the following Expression (2) and ranges from 15% to 50% at a flow velocity ranging from 1 to 3 m/sec over a weld bead and a weld toe portion which are formed by arc welding and are in a state of 700&#xb0; C. or higher,&#x3b1;=100&#xd7;([(O)]+[(CO)]/5)/([()]+[(O)]+[(CO)])&#x2003;&#x2003;Expression (1)&#x3b2;=100&#xd7;[(O)]/([()]+[(O)]+[(CO)])&#x2003;&#x2003;Expression (2) here, [V(X)] is a mixing ratio (volume %) of an inert gas included in the shielding gas, [V(O)] is a mixing ratio (volume %) of oxygen included in the shielding gas, [V(CO)] is a mixing ratio (volume %) of carbon dioxide included in the shielding gas, [V(X)] is a mixing ratio (volume %) of an inert gas included in the oxidation promotion gas, [V(O)] is a mixing ratio (volume %) of oxygen included in the oxidation promotion gas, and [V(CO)] is a mixing ratio (volume %) of carbon dioxide included in the oxidation promotion gas.

Consumable electrode type gas shield arc welding method and arc welding portion

A focused ion beam (FIB) system that can automatically set processing and scanning conditions under which a specimen is processed includes an arithmetic unit for selecting optical conditions for condenser lenses, multiple variable apertures, beam-deflecting electrodes, and an objective lens based on data entered into the input device. The arithmetic unit automatically calculates the processing and scanning conditions under which the specimen is processed by the focused ion beam, according to the selected-optical conditions. The system further includes a setting condition data output portion for outputting data based on the optical conditions and processing and scanning conditions selected and calculated by the arithmetic unit. The system further includes a FIB driver portion for driving the condenser lenses, beam-blanking electrodes, apertures, deflecting electrodes, and objective lens based on the optical conditions and processing and scanning conditions outputted from the data output portion.

Growing community of inventors

Tokyo, Japan

Masahiro Matsuba