SEDL / STP / STP856-EB / STP34523S

Effects of Strain Aging in the Unloading Compliance J Test

Miglin, MT
Research metallurgist, technical advisor, research metallurgist, and supervisor, Babcock & Wilcox, a McDermott Company, Alliance, OH

Van Der Sluys, WA
Research metallurgist, technical advisor, research metallurgist, and supervisor, Babcock & Wilcox, a McDermott Company, Alliance, OH

Futato, RJ
Research metallurgist, technical advisor, research metallurgist, and supervisor, Babcock & Wilcox, a McDermott Company, Alliance, OH

Domian, HA
Research metallurgist, technical advisor, research metallurgist, and supervisor, Babcock & Wilcox, a McDermott Company, Alliance, OH

Pages: 16    Published: Jan 1985

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Abstract

The behaviors of two heats of SA 515 Grade 70 in the unloading compliance J test were compared. Tensile properties were measured for both heats of material; one heat was found to be susceptible to dynamic strain aging. This heat also exhibited a steeper drop in the slope of the J^I-R curve with increasing temperature, and serrated flow during the high-temperature J tests. The magnitude of the serrations varied during each test and with changes in loading displacement rate. Comparison with data from other carbon steels and weld metals showed that a large J^Ic drop with increasing temperature was associated with a large drop in ductility. J tests of strain-aging susceptible materials also showed a marked decrease in load drop from relaxation and peaks in load upon reloading at temperatures at the lower end of the temperature range of dynamic strain aging.