厚壁球铁断裂韧性的初步研究

THE STUDY OF FRACTURE TOUGHNESS ON HEAVYSECTION DUCTILE IRON

本实验从厚壁球铁模拟试块的不同部位取样(由表至里),加工成同样厚度的断裂韧性试样,分析了 K_Q、K_(max)与石墨形态的关系以及 P—△曲线和试样断口的特征,得到了积极有益的结论,并就 K_Q,K_(max)值对球化率不敏感的原因和 K_(IC)平面应变判据在球墨铸铁中失效的可能机理进行了初步探讨。

The samples which were obtained from different parts of the φ150 mm heavysection ductile iron model cylinder(from surface to center)were worked into fracture toughness testblocks with the same dementions.The relationship between K_Q,K_(max)and forms of graphites,the features of P-⊿ carves and the fracture behavior of the samples have been carefully studied. Meanwhile,the reason why the K_Q and K_(max)values are insensitive to the forms of graphites and the failure mechanism of the plane strain state criterion in ductile iron are discussed.