Improvement To The Fatigue Strength Of Drop-forged Specimens By Airless Blast Cleaning

Author:  Kloos, Kaiser, Oppermann
Source:  Conf Proc: ICSP-3, (p.533-540)
Doc ID:  1987046
Year of Publication:  1987
Abstract:  
Drop-forged components are usually airlessly blast cleaned after heat treatment in order to remove the oxide scales. It has been shown in many investigations that this type of treatment also offsets the negative influence of decarburization because it causes strain hardening and introduces residual compressive stresses. The interaction between the shot and the structure of the oxide scales is comprehensively investigated. The results were obtained during "Increasing the Fatigue Strength of Drop-forged Components by Means of a Defined Peening Treatment" research project. The objective of this work was first to carry out an investigation into the influence of the type of shot, the shot hardness, the peening time and the shot size on the bending fatigue behaviour (R = 0) of the material Ck 45 V (R[m] = 813 N/mm[2]). The optimum peening conditions thus found were then applied to other typical forge alloys after usual heat treatments. The peening was applied to the decarburized surfaces with oxide scales which typically appear after forging and the various heat treatments.