Hot-dipped aluminum-zinc or hot-dipped zinc-aluminum-magnesium multiphase steel having yield strength of greater than or equal to 450 mpa and rapid heat-treatment hot plating manufacturing method therefor

Abstract

A hot-dipped aluminum-zinc or zinc-aluminum-magnesium multiphase steel having a yield strength of greater than or equal to 450 MPa and a rapid heat-treatment hot plating manufacturing method therefor. The steel comprises the following components, in percentage by weight: 0.06-0.12% of C, 0.05-0.30% of Si, 1.0-1.8% of Mn, P≤0.015%, S≤0.015%, N≤0.04%, Cr≤0.50%, and further comprises one or both of Ti or Nb, with 0-0.045% of Nb and 0-0.045% of Ti, the balance being Fe and other unavoidable impurities. In addition, the following conditions also need to be met: 0.25≤(C+Mn/6)≤0.40; Mn/S≥150; when no Ti is contained, Nb meets 0.01%≤(Nb−0.22C−1.1N)≤0.03%; when no Nb is contained, Ti meets 0.3≤Ti/C≤0.6; and when Ti and Nb are added in a compound mode, 0.03%≤(Ti+Nb)≤0.07%. According to the present invention, the obtained hot-dipped aluminum-zinc or hot-dipped zinc-aluminum-magnesium steel plate has a yield strength ≥450 MPa, a tensile strength ≥500 MPa and an elongation ≥14%, and also has good strength, toughness and corrosion resistance. The production method therefor has a low cost and a high yield. The steel plate can be used for steel structure buildings such as roofs and walls, and used in household appliances, photovoltaic industries, etc.

Dependencies are inferred from the claim text.