THE TOUGHNESS OF HIGH HARDNESS LAMINAR COMPOSITE STEEL AS INFLUENCED BY SPECIMEN AND CRACK ORIENTATION

摘要

The purpose of the present paper is to extend the study of high hardness laminar composite steel and establish the orientation influence using static and dynamic toughness measurements. The toughness behavior of high hardness laminar composite steel (high carbon, approximately Rc 60, hard layer metallurgically bonded to a medium carbon, approximately Rc 50, softer layer) was investigated. The effort focused on the effect of test temperature, specimen orientation, and crack location on toughness. Charpy V-notch specimens with the notch extending through both the hard and soft layers were tested over a series of temperatures to provide transition curves for both the longitudinal and transverse directions. These transition curves are compared to those obtained from specimens that were surface notched on either the hard or soft side. By precracking similar oriented specimens, information on the fracture toughness was obtained over approximately the same range. These data show the effect of the interface between the hard and soft layers on the various toughness parameters. Lastly, stress corrosion cracking was investigated and K sub ISCC values provided. (Modified author abstract)