Zinc-aluminum-magnesium coated steel plate and preparation method thereof

The invention relates to a zinc-aluminum-magnesium coated steel plate and a preparation method thereof.The method comprises the steps that in-furnace annealing is conducted on strip steel, technological parameters of in-furnace annealing are controlled, and a steel matrix is obtained; wherein the process parameters comprise the in-furnace dew point, the in-furnace oxygen content and the strip steel speed; carrying out hot dipping on at least part of the surface of the steel substrate, and controlling the technological parameters of hot dipping to obtain a zinc-aluminum-magnesium coated steel plate; wherein the technological parameters of the hot dipping comprise the oxygen content of the furnace nose and the dew point of the furnace nose. The technical problem that flaky zinc slag is likely to appear on the surface of an existing zinc-aluminum-magnesium coated steel plate is solved. 本申请涉及一种锌铝镁镀层钢板及其制备方法，所述方法包括：对带钢进行炉内退火，并控制所述炉内退火的工艺参数，得到钢基体；其中，所述工艺参数包括：炉内露点、炉内氧含量以及带钢速度；对所述钢基体的至少部分表面进行热浸镀，并控制热浸镀的工艺参数，得到锌铝镁镀层钢板