Low-alloy and high-strength galvanized plate and production method thereof

The invention discloses a low-alloy and high-strength galvanized plate and a production method thereof. Steel is prepared from the following chemical components by weight percent: 0.04-0.07% of C, equal to or less than 0.03% of Si, 0.3-0.4% of Mn, equal to or less than 0.015% of P, equal to or less than 0.012% of S, 0.020-0.045% of Als, equal to or less than 0.0050% of N, and Fe as balance. Only 0.3-0.4% of cheap Mn alloy is added into the galvanized plate, the low-alloy and high-strength galvanized plate with the yield strength of 260-355MPa and the ductility being more than 28% can be produced under a condition that no other alloying elements are added, and the low-alloy and high-strength galvanized plate has the characteristics of low production cost and good economic benefit. The composition design is optimized in the method, the technological parameters of hot rolling, cold rolling and galvanizing are correspondingly adjusted, Only 0.3-0.4% of cheap Mn alloy is added, and the low-alloy and high-strength galvanized plate with the yield strength of 260-355MPa and the ductility being more than 28% can be produced under a condition that no any other alloying elements are added. The method is low in production cost and can meet the performance requirement of the low-alloy and high-strength galvanized plate.