Accession Number:

AD0604868

Title:

A METALLOGRAPHIC INVESTIGATION OF THE FACTORS AFFECTING THE NOTCH TOUGHNESS OF MARAGING STEELS.

Descriptive Note:

Technical rept.,

Corporate Author:

UNITED STATES STEEL CORP MONROEVILLE PA

Report Date:

1964-07-01

Pagination or Media Count:

58.0

Abstract:

This report describes the results of an investigation of nine maraging steels with widely varying notch toughness 25 to 70 ft-lb Charpy V-notch energy at 190 ksi yield strength. Extraction fractography was used in conjunction with such techniques as light microscopy, thin-film electron microscopy, microprobe analysis, and electronand X-ray-diffraction analysis to identify the causes for the difference in toughness among the nine steels. The results of the investigation indicate that by examining extraction fractographs with metallographic, X-ray- and electrondiffraction, and microprobe techniques it is possible to isolate the major factors responsible for low notch toughness in maraging steels. Thin-film transmission-electron microscopy and analysis of insoluble residue, while generally substantiating the results obtained by analysis of the fractographs, are less definite and therefore less useful than the fractographic studies.

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE