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≤W≤6T, and a blowhole occupancy Br represented by the following formula becomes not more than 50%: Br=(Σdi/L)×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.

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≤W≤6T, and a blowhole occupancy Br represented by the following formula becomes not more than 50%: Br=(Σdi/L)×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.

A bonding system for bonding a semiconductor element to a substrate is provided. The bonding system includes a substrate oxide reduction chamber configured to receive a substrate. The substrate includes a plurality of first electrically conductive structures. The substrate oxide reduction chamber is configured to receive a reducing gas to contact each of the plurality of first electrically conductive structures. The bonding system also includes a substrate oxide prevention chamber for receiving the substrate after the reducing gas contacts the plurality of first electrically conductive structures. The substrate oxide prevention chamber has an inert environment when receiving the substrate. The bonding system also includes a reducing gas delivery system for providing a reducing gas environment during bonding of a semiconductor element to the substrate.

The invention relates principally to a welded steel part with a very high mechanical strength characteristics obtained by heating followed by hot forming, then cooling of at least one welded blank obtained by butt welding of at least one first and one second sheet consisting at least in part of a steel substrate and a pre-coating which is constituted by an intermetallic alloy layer in contact with the steel substrate, topped by a metal alloy layer of aluminum or aluminum-based alloy. This welded steel part claimed by the invention is essentially characterized in that the metal alloy layer (19, 20) has been removed from the edges (36) in direct proximity to the weld metal zone (35), while the intermetallic alloy layer (17, 18) has been left in place, and in that over at least a portion of the length of the weld metal zone (35), the ratio between the carbon content of the weld metal zone (35) and the carbon content of the substrate (25, 26) of either the first or the second sheet (11, 12) having the higher carbon content (Cmax) is between 1.27 and 1.59. The invention likewise relates to a method for the fabrication of a welded steel part as well as the use of this welded steel part for the fabrication of structural or safety parts for automotive vehicles.

A method of forming a ferrous metal case-hardened layer using additive manufacturing. The method includes delivering, by a material delivery device, a filler material to a surface of a substrate. The substrate includes a first ferrous metal. The filler material includes a second ferrous metal and a carbon-based material. The method also includes directing, by an energy delivery device, an energy toward a volume of the filler material to join at least some of the filler material to the substrate to form a component.

Forward feeding for feeding a welding wire in a direction of a workpiece and backward feeding for feeding in an opposite direction to the forward feeding are alternately performed, and the welding wire is fed at a wire feeding speed cyclically changed in a predetermined cycle and at a predetermined amplitude to perform welding by repeating an arc period and a short-circuit period. Provided during forward feeding, stopping feeding of the welding wire from a time of an elapse of a half cycle of a change of the wire feeding speed to an elapse of a first feeding stop period, and feeding the welding wire forward at a first feeding speed from an elapse of the first feeding stop period to an elapse of a predetermined period. The welding wire is fed backward after the elapse of the predetermined period.

Forward feeding for feeding a welding wire in a direction of a workpiece and backward feeding for feeding in an opposite direction to the forward feeding are alternately performed, and the welding wire is fed at a wire feeding speed cyclically changed in a predetermined cycle and at a predetermined amplitude to perform welding by repeating an arc period and a short-circuit period. Provided during forward feeding, stopping feeding of the welding wire from a time of an elapse of a half cycle of a change of the wire feeding speed to an elapse of a first feeding stop period, and feeding the welding wire forward at a first feeding speed from an elapse of the first feeding stop period to an elapse of a predetermined period. The welding wire is fed backward after the elapse of the predetermined period.

A pulse welding period includes a first peak period for supplying a first peak current to a welding wire, a first base period for supplying a base current smaller than the first peak current to the welding wire, a second peak period for supplying a second peak current to the welding wire after alternately repeating the first peak period and the first base period (n1) times (n is an integer equal to or larger than 2), and a second base period for supplying the base current to the welding wire. The second peak current is larger than the first peak current, and droplets are transferred from the welding wire during the second peak period or the second base period.

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 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 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 C. or higher,
=100([V.sub.1(O.sub.2)]+[V.sub.1(CO.sub.2)]/5)/([V.sub.1(X)]+[V.sub.1(O.sub.2)]+[V.sub.1(CO.sub.2)])Expression (1)
=100[V.sub.2(O.sub.2)]/([V.sub.2(X)]+[V.sub.2(O.sub.2)]+[V.sub.2(CO.sub.2)])Expression (2) here, [V.sub.1(X)] is a mixing ratio (volume %) of an inert gas included in the shielding gas, [V.sub.1(O.sub.2)] is a mixing ratio (volume %) of oxygen included in the shielding gas, [V.sub.1(CO.sub.2)] is a mixing ratio (volume %) of carbon dioxide included in the shielding gas, [V.sub.2(X)] is a mixing ratio (volume %) of an inert gas included in the oxidation promotion gas, [V.sub.2(O.sub.2)] is a mixing ratio (volume %) of oxygen included in the oxidation promotion gas, and [V.sub.2(CO.sub.2)] is a mixing ratio (volume %) of carbon dioxide included in the oxidation promotion gas.

A method for joining a first part formed of an aluminum material to a second part formed of a steel material by metal inert gas welding and cold metal transfer is provided. An aluminum filler material forms a fillet joint between the parts and provides a structure for automotive body applications, such an aluminum bumper extrusion joined to a steel crush box connection. The first part includes a notch for hiding the start and end of the joint. A transition plate formed of a mixture of aluminum material and steel material can be disposed between the first part and the second part to provide the notch. The second part can include a mechanical fastener further joining the parts together. In another embodiment, the second part includes a plurality of dimples and is welded to the first part along the dimples.