MATERIAL FOR WELDED STRUCTURE (VERSIONS) Russian patent published in 2000 - IPC

FIELD: materials for welded structures. SUBSTANCE: material for welded structure from aluminum alloy contains, wt.%: Mg 3.0-5.0; Mn 0.5-1.0; Fe up to 0.25; Si up to 0.25; Zn up to 0.40; and in cases of necessity, at least, one element is taken from group: Cr up to 0.25; Cu up to 0.20; Ti up to 0.20; Zr up to 0.20; the other elements up to 0.05 each, and 0.15 on the whole. In this case, Mn+2Zn exceeds 0.75, preferably, above 0.8. Volume fraction if material dispersoids amounts to above 1.2%. Crack velocity of material measured for R=0.1 is more than: 22 Mpa with da/dn=5×10^-4 mm/cycle, 26 Mpa at da/dn=5×10^-3 mm/cycle. Fatigue strength of material measured at simple bending with R= 0.1 in longitudinal- transverse direction is more than: 100 000 cycles at maximum stress above 280 MPa, 1 000 000 cycles at maximum stress above 220 MPa, 10 000 000 cycles above 200 MPa, and material welded by fusing has Vickers hardness in welded zone in excess of 80. Material may be produced in form of sheets with thickness of less than 2.5 mm only by hot rolling and is applicable in sea construction, manufacture of trucks, or as material used for welded bicycle frames. EFFECT: welded material featuring higher fatigue strength. 3 tbl, 1 ex