Stress relief cracking in copper-precipitation strengthened HSLA-100 steel
McNutt, Steven A.
Losz, J. Mauro B.
MetadataShow full item record
The US Navy is currently developing a new family of high-strength , low-alloy steels which derive a significant portion of their strength from copper precipitation. These highly weldable steels require little or no preheat. resulting in substantial cost savings. The first of these steels. HSLA-80, has been certified for ship construction, but recent studies have indicated some susceptibility to stress relief cracking in weldments. HSLA-100, a modification of HSLA-80, is now being considered for several higher-strength naval structures. Stress-relief cracking has not been studied previously in this steel and is the subject of investigation in this work. The steel weldments were loaded below their yield strength, heated to temperatures of 550°-650° C, and permitted to stress relieve for one hour. At all temperatures, the steel exhibited susceptibility to stress relief cracking in certain stress ranges. Optical and scanning electron microscopy exhibited intergranular cracking which always traversed the coarse-grained region of the heat-affected zone. Auger and transmission electron microscopy indicated high concentrations of alloying elements at the grain boundaries. Stress-relief cracking was associated with the diffusion of alloying elements to the prior austenite grain boundaries.
Approved for public release; distribution is unlimited
Showing items related by title, author, creator and subject.
Stress effects on transfer from virtual environment flight training to stressful flight environments McClernon, Christopher K. (Monterey, California: Naval Postgraduate School, 2009-06);The purpose of this research was to investigate the effects that stress training has on stressful flight operations to mitigate the human factors preconditions to aircraft accidents. In addition, stress training implementation ...
Ballantine, James Clement, Jr. (Massachusetts Institute of Technology, 1967-06);The objective of this thesis is to obtain an understanding of the variation in stress on the cardinal axes of a circular penetration with elliptical reinforcements in a simulated stiffened cylindrical pressure vessel. The ...
An exploration of cognitive agility as quantified by attention allocation in a complex environment Mariscal, Miriam C. (Monterey, California: Naval Postgraduate School, 2017-03);This thesis supports the Army's mission to establish a measure for cognitive agility in soldiers. It examines attention-allocation patterns as quantified by eye-tracking data collected while subjects played a military-relevant ...