Comparison of mechanical and metallurgical properties of hollow and solid forged products

Some mechanical and metallurgical properties of hollow and solid long forged products are compared. The metallurgical properties include such micro- and macro-structural characteristics as the grain size and grain flow patterns. Mechanical evaluation was performed by means of hardness testing. Some theoretical analyses were also carried out. The results indicate that the hollow or mandrel forged products possess better properties. Both the mechanical and metallurgical properties are more uniform and homogeneous through the thickness direction in such products. By contrast, in the solid forged parts, there is a gradient in the micro- and macro-structural properties from the surface to the internal areas. These non-uniformities can reduce the quality and reliability of such products and cause manufacturing problems in the processes that follow.