Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Shoko Oami

Shinji Kodama

Koichi Sato

Yoshiaki Nakazawa

Yasuaki Naito

Tasuku Zeniya

Masahiro Matsuba

Yujiro Tatsumi

Masahiro Ogawa

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 fillet arc welded joint formed by fillet arc welding at least two metal members, comprising a remelted and solidified portion obtained by irradiating a laser at a weld toe portion of the fillet arc welding of at least one metal member and a region including a boundary of the heat affected zone caused by the fillet arc welding at the surface of that metal member, the remelted and solidified portion being a range from a surface of the metal member to a depth of &#xbd; or less of the thickness of that metal member, an average effective crystal grain diameter of prior austenite at a heat affected zone from a boundary of the remelted and solidified portion at the surface of the metal member to a depth of 0.1 mm in the thickness direction of the metal member being 20 &#x3bc;m or less.

Fillet arc welded joint and method for producing same

This welded structure member includes a base metal member including a first surface and a second surface; a joined metal member including an abutting surface of which an end surface abuts onto the first surface; a weld bead which is formed on the first surface; and a weld overlay section which is formed on the second surface of the base metal member, in which the weld bead includes a weld bead end section in a position which is separated to the front of the abutting end section.

Welded structure member and manufacturing method thereof

The present invention provides a fillet welded joint and a method of production of a fillet welded joint which can raise the productivity of the method of production of a fillet welded joint and a fillet welded joint without sacrificing the strength against fatigue fracture of the welded structural member. The fillet welded joint of the present invention is a fillet welded joint formed by fillet welding at least two metal members, wherein, on the surface of at least one of the metal members, the fillet welded joint comprises a press bead of a rib-shaped projection provided by press-forming so as to project upward to the side having a weld bead formed by the fillet welding, and part of the press bead contacts or overlaps the weld bead.

Growing community of inventors

Tokyo, Japan

Shoko Oami