The present invention relates to a pre-stressed steel sheet and a method a method of manufacturing the same.

An embodiment of the present invention provides a pre-stressed steel sheet comprising: a base material; and a plurality of weld lines formed on the base materials, wherein the average spacing between each pair of the weld lines is equal to or greater than five times the width of the weld lines and equal to or less than half the width of the steel sheet.

According to an aspect of the present invention, a pre-stressed steel sheet having improved bendability can be provided, and accordingly when the pre-stressed steel sheet is applied to a structural member such as a girder or beam, the bendability of a structure can be improved.

A contact tip assembly having an electric contact unit containing a contact tip with an electric energy source, where the electric contact unit is positioned at a distance away from the outlet opening of a guide.

A three-dimensional (3D) metal object manufacturing apparatus is configured to increase the oxidation of ejected melted metal drops for the formation of metal support structures during manufacture of a metal object with the apparatus. The oxidation can be increased by either increasing a distance between the ejector head and a platform supporting the metal object or by providing an air flow transverse to the direction of movement of the melted metal drops, or both.

An additively manufactured object formed by depositing weld bead layers, each of the weld bead layers being obtained by melting and solidifying a filler metal made of a mild steel, the additively manufactured object includes a plurality of the weld bead layers having a ferrite phase with an average grain diameter of 11 μm or less in a part except for a surface oxide film.

A welding or additive manufacturing system includes a contact tip assembly having first and second exit orifices. A wire feeder is configured to deliver a first and second wire electrodes through the exit orifices. An arc generation power supply is configured to output a current waveform to the wire electrodes simultaneously, through the contact tip assembly. The current waveform includes a bridging current portion, and a background current portion having a lower current level than the bridging current portion. The bridging current portion has a current level sufficient to form a bridge droplet between the wire electrodes before the bridge droplet is transferred to a molten puddle during a deposition operation. Solid portions of the wire electrodes do not contact each other during the deposition operation. The bridge droplet is transferred to the molten puddle during a short circuit event between the molten puddle and the wire electrodes.

In preparing a built-up object by depositing beads, in a step of dividing into the bead model, a trapezoidal bead model a cross section of which is a trapezoidal shape is applied to a position where the bead is formed in a portion not adjacent to an existing bead, and a parallelogram bead model a cross section of which is a parallelogram is applied to a position where the bead is formed adjacent to a bead that is already formed, in the parallelogram bead model opposite sides in the deposition direction of the bead being parallel to each other, and opposite sides in the bead arrangement direction being parallel to a side of another bead mode that is adjacent.

Wire arc additive manufacturing-spinning combined machining device and method are provided. The machining device includes a spinning mechanism and a fused deposition modeling mechanism. The spinning mechanism includes a machine tool and a spinning head. The spinning head is installed on the machine tool by a main shaft, and the main shaft is configured to drive the spinning head to rotate to achieve the movement in three vertical directions. The spinning head includes a spinning base and balls. Each of the balls is installed in a corresponding one of arc grooves at a bottom of the spinning base. The fused deposition modeling mechanism includes a moving track, a robot and a heat source generator. The arc moving track is arranged around the machine tool in a surrounding mode. The robot is movably installed on the moving track. The heat source generator is installed at a tail end of the robot.

A generalized additive modeling approach to separate global geometric shape deformation from surface roughness is provided. Under this statistical framework, tensor product basis expansion is adopted to learn both the low-order shape deformation and high-order roughness patterns. The established predictive model enables the optimal geometric compensation for product redesign to reduce shape deformation from the target geometry without altering process parameters. Experimental validation on WAAM manufactured cylindrical walls of various radi shows the effectiveness of the proposed framework.

A laminate shaping method includes: a unit step repeatedly performed, the unit step including a step of forming a laminate shaped portion by laminating metal layers formed of weld beads, and a step of forming a processed side surface by cutting a shaped portion side surface facing a second direction intersecting a first direction, in which, in the step of forming the processed side surface, the shaped portion side surface is cut so that a receiving portion projecting in the second direction with respect to the processed side surface is formed at an uppermost layer of the laminate shaped portion in the first direction, and when the unit step is repeated, in the step of forming the laminate shaped portion, a new metal layer is laminated so as to overlap an upper surface of the receiving portion in the first direction.

An arc welding apparatus and corresponding method includes a torch, a non-consumable electrode and a consumable electrode both disposed within the torch, a wire feeder configured to feed the consumable electrode in a vicinity of the non-consumable electrode, a first power source and a second power source that provide independent current, respectively, to the non-consumable electrode and the consumable electrode, and a weld process controller to control outputs of the first power source and the second power source such that a concentrated arc is formed, as a heat source, between the non-consumable electrode and a workpiece, and an inter-electrode arc is formed between the consumable electrode and the non-consumable electrode to melt the consumable electrode. The approach is characterized by low heat input, low distortion, low spatter, and the relative high speed or high deposition of laser and laser-MIG hybrid and other forms of multi-wire/multi-electrode welding, cladding, and additive manufacturing.