The present invention relates to a steel material composite, comprising a core layer of a higher-strength or high-strength steel and, integrally bonded to the core layer on one or both sides, an outer layer of ferritic, chemically resistant steel. Corresponding flat steel products are distinguished by favourable properties with respect to their strength, ductility, low sensitivity to hydrogen-induced crack formation and favourable corrosion resistance. The present invention also relates to a method for producing a corresponding steel material composite and to the use of such steel material composites in vehicle structures and in particular in bodywork structures.

Structure including joint structure of dissimilar materials comprises a roof panel and a skeletal body. The roof panel has a bent portion at its end and is a panel member made of an aluminum alloy. The skeletal body has a support portion for supporting the first member and is made of steel. The roof panel and the skeletal body are joined by continuous welding of a vicinity of an apex of the bent portion of the roof panel and the support portion of the skeletal body, a reinforcing plate is joined to the roof panel at least partially along the joining portion with the skeletal body.

A method for producing a part includes providing a first and a second precoated sheet (1,2), butt welding the first and second precoated sheets (1) to obtain a blank (15), and heating the blank (15) to a heat treatment temperature at least 10 C. lower than the full austenitization temperature of the weld joint (22) and at least 15 C. higher than a minimum temperature T.sub.min: $T_{\min }\left(C.\right)=\mathrm{AC}3\left(\mathrm{WJ}\right)-\frac{{}_{\mathrm{IC}}^{\max }}{100}\left(\mathrm{Ac}3\left(\mathrm{WJ}\right)-673-40\mathrm{Al}\right).$ where Ac3(WJ) is the full austenitization temperature of the weld joint (22) ${}_{\mathrm{IC}}^{\max }=(1-\frac{\left(1+\right)(}{}$

A method for producing a welded blank (1) includes providing two precoated sheets (2), butt welding the precoated sheets (2) using a filler wire. The precoating (5) entirely covers at least one face (4) of each sheet (2) at the time of butt welding. The filler wire (20) has a carbon content between 0.01 wt. % and 0.45 wt. %. The composition of the filler wire (20) and the proportion of filler wire (20) added to the weld pool is chosen such that the weld joint (22) has (a) a quenching factor FT.sub.WJ: FT.sub.WJ?0.9FT.sub.BM?0, where FT.sub.BM is a quenching factor of the least hardenable substrate (3), and FT.sub.WJ and FT.sub.BM are determined: FT=128+1553?C+55?Mn+267?Si+49?Ni+5?Cr?79?Al?2?Ni.sup.2?1532?C.sup.2?5?Mn.sup.2?127?Si.sup.2?40?C?Ni?4?Ni?Mn, and (b) a carbon content C.sub.WJ<0.15 wt. % or, if C.sub.WJ?0.15 wt. %, a softening factor FA.sub.WJ such that FA.sub.WJ>5000, where FA=10291+4384.1?Mo+3676.9Si?522.64?Al?2221.2?Cr?118.11?Ni?1565.1?C?246.67?Mn.

There is provided a resistance spot welding apparatus including a first rod-shaped electrode body, second rod-shaped electrode body, first ring-shaped member, second ring-shaped member, first elastic body, and second elastic body. The first rod-shaped electrode body and second rod-shaped electrode body are arranged facing each other, the first rod-shaped electrode body is inserted into a through hole of the first ring-shaped member, the first elastic body is connected to an opposite side of first ring-shaped member to second rod-shaped electrode body side, the first rod-shaped electrode body and first ring-shaped member are not electrically connected to each other, the second rod-shaped electrode body is inserted into a through hole of the second ring-shaped member, the second elastic body is connected to an opposite side of second ring-shaped member to first rod-shaped electrode body side, and the second rod-shaped electrode body and second ring-shaped member are not electrically connected each other.

A method for butt-welding of sheet metal, especially bodywork in the motor vehicle industry, where at least two flat workpieces with any desired contours are fed to a machining process. In a first sub-process, the workpieces are positioned in relation to one another forming a minimal gap and secured in place with holding means. In another sub-process, the position and width of the gap are measured continuously immediately before welding together and the measurements are used to control a laser welding head. The laser welding head is fit with a rotatable twin-spot lens, where the relative alignment of a main spot to an auxiliary spot is controlled depending on the absolute position of the gap and the gap width during the welding process while the processing lens of the laser welding head is rotated around the laser beam axis with the angle of rotation alpha.

There is provided a blank in which two or more starting materials that overlap each other are joined with each other by laser welding, including the blank has a single layer region, in which only one of the starting materials is present, and a multi-layer region, in which two or more of the starting materials overlap each other, laser welding is continuously applied to the multi-layer region and the single layer region, and one end of a laser weld zone is located at an end portion of the single layer region of the blank, and the one end forms a concave-shaped welding end portion having a concave shape when the blank is viewed from an end face.

A method for forming a large metallic component, a friction stir welded component and a friction stir welded blank are provided. The method includes positioning a first metallic plate and a second metallic plate in an abutting arrangement. The first metallic plate and the second metallic plate have corresponding faying surfaces at a point of abutment. A backing plate is attached spanning the point of abutment adjacent the faying surfaces. The first metallic plate is friction stir welded to the second metallic plate to form a friction stir weld along the faying surfaces. The backing plate receives an end of a friction stir welding tool curing the friction stir welding. The backing plate is removed to form a welded blank. The welded blank is formed into a component form. The component is heat treated and aged to form the large metallic component. The friction stir weld in the welded blank has a stable microstructure having little or no abnormal grain growth during elevated temperature forming, heat treatment and aging.

According to an exemplary embodiment of the present disclosure, disclosed is an aluminum coated blank that includes a first coated steel sheet; a second coated steel sheet connected to the first coated steel sheet; and a joint portion that connects the first coated steel sheet to the second coated steel plate at a boundary between the first coated steel sheet and the second coated steel sheet.

Structural members for a vehicle at least partially configured for supporting bending loads and methods for manufacturing such structural members are provided. A structural member includes a main piece with a substantially U-shaped cross-section comprising a bottom, a first side wall and a second side wall, wherein the main piece comprises a region configured for supporting bending loads. The structural member includes a first patch having a first patch edge and an opposite second patch edge, wherein the first patch is attached to the main piece by continuous laser welding inside the first patch substantially along the first patch edge and along the second patch edge at least in the region configured for supporting bending loads.