Effects Of Shot Peening On The Corrosion Fatigue Properties Of Spring Steels

Author:  Kaiser, B.
Source:  Conf Proc: ICSP-3, (p.667-674)
Doc ID:  1987026
Year of Publication:  1987
Abstract:  
Besides heat treatment and mechanical surface strengthening methods to improve the fatigue limit, corrosion preventing procedures have to be employed for longer durability of safety components such as vehicle springs. These springs are corrosion protected by different systems of varnish coats today. A preceding shot peening process not only results in an improvement of fatigue strength but also in a clean and enlarged metallic surface giving better adhesive conditions for the varnish coat. Shot peening, however, can not fundamentally modify the state of active corrosion fatigue in which low-alloy, high-strength spring materials are when attacked by tap water or sodium chloride solution without or with a damaged corrosion protection layer. Although the basic mechanisms of corrosion fatigue fo steels in active or passive conditions have been examined in detail already only little information is known about the corrosion fatigue behavior of spring steels. To study the corrosion fatigue properties of three typical spring steels and to determine optimal corrosion protecting methods, extensive research work is being carried out. This paper deals with some results of corrosion fatigue tests with the spring steel 50 CrV 4 and the comparison between mechanically polished and shot peened specimens.