INVESTIGATION OF FRACTURED STEEL PLATES REMOVED FROM WELDED SHIPS.
Progress rept. for 30 Dec 48.
NATIONAL BUREAU OF STANDARDS WASHINGTON D C
Pagination or Media Count:
The relations previously reported between the nature of the fractures in the plates and their notched bar properties are confirmed by the tests of the additional plates. With increases of 10 percent to 45 percent in the number of plates tested in the various groups, there were no significant changes in the average values of the notched bar properties, and with few exceptions the new data fell within the previously reported ranges of values. In general the transition temperatures of the plates involved in the more recent casualties were lower than the averages for plates tested previously. This may be an indication of a significant trend toward lower transition temperatures of the plates involved in failures, but the evidence is not sufficient to warrant a definite conclusion. Tensile tests using different types or sizes of test specimens were made on several of the plates. In nearly all of these duplicate tests slightly higher values of the tensile strength, and considerably higher percentages of elongation were obtained with the smaller specimens. The manganesecarbon ratios of 6 of the plates were higher than was found for any of the plates tested previously. There was no correlation between these higher manganesecarbon ratios and the transition temperatures of the plates or the nature of the fractures which occurred in service.
- Metallurgy and Metallography
- Marine Engineering