Microstructure influence on fatigue behaviour of nodular cast iron

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:556

Article

Canzar, P.¹  Tonkovic, Z.¹  Kodvanj, J.¹ 

[1] Univ Zagreb, Fac Mech Engn & Naval Architecture, Inst Appl Mech, Zagreb 10000, Croatia

关键词: Nodular cast iron;    Microstructure;    Experiment;    Cyclic tests;    Fatigue;    Crack growth;   

DOI  :  10.1016/j.msea.2012.06.062

来源: Elsevier

【 摘 要 】

The present paper evaluates the fatigue life of ductile nodular cast iron EN-GJS-400-18LT with four different microstructures. Characterisation of the graphite morphology and the matrix microstructure is performed on 50 samples for every material type. Tensile stress-strain curves, symmetrical and unsymmetrical stress-strain hysteresis loops, cyclic stress-strain curves, crack resistance curves and fatigue life curves of these four microstructures are obtained. Experimental results show that size, shape and distribution of the graphite nodules has no significant influence on cyclic hardening of the material but they play a great role in the crack initiation and propagation process. It is shown that the larger irregularly shaped nodules reduce fracture toughness and fatigue strength. Furthermore, the results demonstrated that pearlitic phase does not strongly affect fatigue life if its proportion does not exceed 10%. The monitoring of crack length during the tests is performed by an optical method developed in the present work. (c) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

Free