ArcelorMittal S.A.
METHOD FOR PRODUCING A WELDED STEEL BLANK AND ASSOCIATED WELDED BLANK

Abstract:

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.gtoreq.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.times.C+55.times.Mn+267.times.Si+49.times.Ni+5.times.Cr-79.ti- mes.Al-2.times.Ni.sup.2-1532.times.C.sup.2-5.times.Mn.sup.2-127.times.Si.s- up.2-40.times.C.times.Ni-4.times.Ni.times.Mn, and (b) a carbon content C.sub.WJ<0.15 wt. % or, if C.sub.WJ.gtoreq.0.15 wt. %, a softening factor FA.sub.WJ such that FA.sub.WJ>5000, where FA=10291+4384.1.times.Mo+3676.9Si-522.64.times.Al-2221.2.times.Cr-118.11.- times.Ni-1565.1.times.C-246.67.times.Mn.