FRACTO-METALLOGRAPHIC ANALYSIS OF FATIGUE CRACK GROWTH IN PEARLITIC STEELS
High-strength prestressing steel wires are one of the two constituents of prestressed concrete structures.It has undergone strong plastic deformations which modify drastically its microstructure at the two basic microstructural levels,namely the pearlite colony and the pearlitic lamellae 1-4 in the form of progressive slenderizing and orientation of the colonies parallel or quasi-parallel to wire axis or cold drawing direction 1,2 as well as increasingly closed packing and orientation of the lamellae also in the drawing direction 3,4.This paper deals with the macroscopic consequences of such a microstructural arrangement,in the matter of fatigue performance (in the Paris regime of cracking) of the progressively drawn pearlitic steel wires.Whereas in the hot rolled bar the crack advances in pure mode Ⅰ (with almost no crack deflection),in the cold drawn wire the crack grows under a global mode Ⅰ,but with a certain local mode Ⅱ,I.e.,frequent local deflections are observed in the fatigue crack path,as a consequence of the microstructural orientation described in previous paragraphs.This tortuous crack path is one of the basic explanations of the improvement of fatigue performance in the cold-drawn wire.
J.Toribio B.González J.C.Matos
Department of Materials Engineering,University of Salamanca E.P.S.,Campus Vinato,Avda.Requejo 33,49022 Zamora,Spain
国际会议
第二届国际非均质材料力学会议(The Second International Conference on Heterogeneous Material Mechanics)
安徽黄山
英文
440
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）