| 摘要 |
The invention discloses a steel plate resistant to zinc-induced crack and a manufacturing method therefor. A low-alloy steel subjected to low C-ultra low Si-high Mn-low Al-(Ti + Nb) microalloying treatment is taken as a basis; the A1 content in the steel is appropriately reduced; the conditions are controlled so that Mn/C ‰¥ 15, [(%Mn) + 0.75(%Mo)] x (%C) ‰¤ 0.16, Nb/Ti ‰¥ 1.8 and Ti/N is between 1.50 and 3.40, CEZ ‰¤ 0.44% and the B content is ‰¤ 2ppm, Ni/Cu > 1.50; a Ca treatment is performed and the Ca/S ratio is controlled between 1.0 and 3.0, with (%Ca) x (%S) 0.28 ‰¤ 1.0 x 10 -3 ; and a TMCP process is optimized, so that a finished steel plate has a micro-structure of ferrite + bainite colonies which are tiny and dispersedly distributed, with an average grain size of not greater than 10 µm, has homogeneous and excellent mechanical properties, excellent weldability and zinc-induced crack resistance, and is thus especially suitable as a zinc-spray coated corrosion-resistant steel plate for marine structures, a zinc-spray corrosion-resistant steel plate for extra-high voltage power transmission structures, a zinc-spray coated corrosion-resistant steel plate for coast bridge structures, and the like. |
