Abstract: The edge shear delamination of A709M-50F-2ZT steel plate seriously affects the product quality. In order to prevent such edge layer defects from recurring, the 30 mm thick A709M-50F-2ZT edge shear layered steel plate was taken as the research object. With the help of metallographic microscope, scanning electron microscope, etc., the metallographic structure and inclusions were analyzed. The results show that the internal cracks in the area of 1/3 to 1/4 of the thickness of the steel plate are the main cause of shear cracking. The shear delamination of the edge of the steel plate was eliminated in actual production by improving the purity of molten steel, reducing pouring overheating, strengthening the maintenance of continuous casting equipment.

Key words: A709M-50F-2ZT steel plate, bilateral shear layering, internal crack, process optimization