SEDL / STP / STP733-EB / STP33442S

Characterization of the Fracture Behavior of Fine-Grained High-Strength Low-Alloy (HSLA) Steels and Iron-Base Alloys Under Low-Temperature and Mechanical Environments

Krishnadev, MR
Associate professor, Laval University, Quebec

Cutler, LR
Graduate students, Laval University, Quebec

Sojka, GJ
Graduate students, Laval University, Quebec

Gauvin, P
Students, Laval University, Quebec

Hamel, G
Students, Laval University, Quebec

Pages: 19    Published: Jan 1981

Download this paper for $25 PDF (696K)          View License Agreement
Abstract

This paper discusses the use of different fractographic techniques to characterize the fracture morphology of high-strength low-alloy (HSLA) steels with a variety of fine-grained microstructures and iron-base alloys strengthened by intermetallic precipitates in order to understand the various fracture mechanisms controlling their fracture resistance under low-temperature and mechanical environments. The fractographic techniques that have been used are conventional techniques, scanning electron fractography, sectioning techniques, and a newly developed chemical polishing method in conjunction with the Nomarski interphase contrast technique. The mechanical tests that have been used are tensile, notched-tensile, instrumented impact testing with precracked Charpy V-notch specimens, low-cycle fatigue, and high-cycle fatigue. A comprehensive characterization of the fracture morphology of the HSLA steels developed for arctic applications has resulted. Important features of the fracture (such as “splitting,” striations, ductile tearing, quasi-cleavage, microvoid coalescence, unit fracture path, persistent slip bands) have been identified and related to the mechanical behavior of the materials.