【摘要】 本文通过图象分析仪,采用小岛分析法,研究了四级锚链钢（20SiMnCrNiMo）在四种调质态下的延性断裂表面的分形（fractal）维数（D_F）。分析了延性断裂韧性(J_0.2)与其断裂表面的 D_F 间关系。实验结果表明:对试验钢而言,随着断裂表面的 D_F 增加,J_0.2的自然对数呈线性地下降。由此可见,利用分形维数作延性断裂的特征参数是可行的。与传统的试验方法相比,这是分析材料断口的有效新方法,它可利用材料破坏的断口直接地去分析并推知其断裂特性。更多还原

【Abstract】 The fractal dimension（D_F）of ductile fracture surface forgrade 4 cable chain steel（20SiMnCrNiMo）under four kinds of hardened and tempered states is studied by means of quantimet and slit island analysismethod.The relationship between ductile fracture toughness(J_0.2andfractal dimension of fracture surface is analysed.It has been showed thatin J_0.2decrease linearly with increasing of D_F of fracture surface.So,itis feasible to take the fractal dimension as a feature parametar of ductilefracture.Compared with convetional testing methods,the new method is aneffective way in analysing fracture of matarials.The fracture character ofmaterials can be infered by analysing fracture surface of failure samples.更多还原