Influence of Ferrite Content on Fatigue Strength of Quenched and Tempered 42CrMoS4 Steel

• Main Author: Hanno, Mithaq Elias
• Format: Others
• Language: English
• Published: KTH, Materialvetenskap 2012
• Subjects: Quenched and Tempered Steel; Fatigue strength; Ferrite Content
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102023

Specimens of steel 42CrMoS4 were quenched from the austenite (γ) and the ferrite (α) + austenite + cementite phase fields to produce fully martensitic matrices with 0 – 14 % ferrite dispersed in the matrix. After tempering at 300°C or 600°C mechanical and fatigue properties were determined. As expected yield strength, tensile strength and hardness decreased with increased tempering temperature and ferrite content. Quite unexpected, the fatigue properties were mildly affected. A small amount of ferrite, approximately 3% even appears to improve the fatigue strength. Then, at even higher ferrite amounts, slightly below 20% the fatigue strength appears to decrease again.