The Effect of Silicon on the Brittle Fracture of Ferritic-Pearlitic Steels

Abstract

The effect of silicon on the brittle fracture characteristics of ferritic-pearlitic steels has been investigated by means of both Charpy impact and double cantilever beam tests.
Although the increase of silicon content largely raised the Charpy impact transition temperature at the same pearlite colony size, the brittle fracture propagation-arrest properties determined by the DCB test was not affected by silicon content. Since the Charpy transition temperature was closely related to the temperature for cleavage fracture initiation obtained by the fatigue notched COD test, the brittle fracture initiation properties is expected to be deteriorated by increasing silicon content. Such brittle fracture characteristics were in quite good agreement with the temperature dependence of lower yield stress.