Accession Number:

AD0600937

Title:

WELDING CHARACTERISTICS OF MARAGING STEELS - II.

Descriptive Note:

Technical rept.

Corporate Author:

UNITED STATES STEEL CORP MONROEVILLE PA

Personal Author(s):

Report Date:

1964-04-01

Pagination or Media Count:

22.0

Abstract:

Results of the study showed that 2-inch-thick plates from three production heats of 180- to 210-ksi-yield-strength grades of maraging steel were susceptible to weld-heataffected-zone cracking. The cracks were internal originating at or adjacent to the overaged region in the heataffected zone, appeared to be exclusively associated with areas of nonmetallic inclusions, and were parallel to the rolled plate surface. Results of metallographic examination indicated that the inclusions were titanium carbides, nitrides, or carbonitrides, and aluminum oxides. The results also indicated that specimens having a solution-annealed-and-aged prior microstructure and welded with a 300 F preheat exhibited a lower crack susceptibility than specimens having a solution-annealed prior microstructure and welded with no preheat. The results suggested that the cracks initiate where a plane of weakness area of concentrated inclusions intersects the aged region where the stress is high because of the combined effects of shrinkage and transformation forces. The cracks then propagate along the planes of weakness under the influence of long-range shrinkage stress. Generally, the results of the present work suggest that the observed weldheat-affected-zone cracks could be eliminated by 1 eliminating the planes of weakness or 2 reducing the amount of shrinkage andor transformation stress induced by welding. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE