The toughness experiments indicate that the fracture of macro-structure of the austenite-bainite ductile cast iron is of brittle fracture, while the fracture of micro-structure is of mainly ductile fracture with dimple appearance.

• 韧性实验表明:奥氏体-贝氏体球铁的断口,宏观结构呈脆性断口,微观结构呈韧性断口,即主要形成韧窝断口。