Charpy V-Notch Impact Behaviour of Structural Steels Subjected to Specific Manufacturing Conditions - Part II: Notch Manufacturing Conditions

摘要

The influence of notch manufacturing on the Charpy V-notch impact behaviour is undesirable and impairs the informative value of the V-notch impact tests. For this reason, specific investigations are carried out in the present part II to resolve more precisely the influence of specifically varied notch manufacturing conditions - surface work hardening, roughness, and residual stresses - on the Charpy V-notch impact behaviour of steel specimens. Here, a solid starting point is provided by the effects of significant geometric parameters on the impact energy (part I), which were obtained from specimens of the same steels manufactured under approximately constant conditions. Specifically varied notch manufacturing conditions (part II) can, as shown, exert an influence on the notch impact energy. The notch impact energy decreases with increasing roughness of the notch root surface and similarly with increasing surface work hardening. Residual stresses caused by manufacturing have virtually no influence. Thus for practical purposes, manufacturing of the notched specimen should be carried out under constant and specified conditions. Attention must be paid to wear of the employed cutting tools.