Effect of the Shear Component of Loading on the Damage and Microrelief of Fractures of Specimens of Low-Carbon Steel

Resumo

Special features of the microrelief of fractures of notched specimens of steel 20 tested under shear, opening and mixed loading modes are studied by x-ray diffraction analysis and analysis of fracture surfaces. The degree of the damage of the specimens is assessed. It is shown that increase in the contribution of the shear component lowers the degree of distortion of crystal structure on the fracture surface, which agrees with reduction of the area of the plastic zone, of the depth of the fracture microrelief, and of the relative width of the shear region. The physical broadening of the x-ray diffraction line obtained from the fracture surface is shown to be correlated with the mode of loading of the specimen.