Head, Fracture Section, Engineering Department, The Welding Institute, Research Laboratory, Abington, Cambridge,
Pages: 27 Published: Jan 1984
This paper comprises a study of the resistance to the propagation of a ductile tear in 316 stainless steel parent plate in all six orientations, and submerged-arc and manual metal arc weld metal and heat-affected zone (HAZ) regions in stainless weldments at 370 and 540°C. Tests were carried out in bending and tension in both load and displacement control at 370°C. The propagation resistances of the various regions are assessed from the measurement of resistance curves and maximum load toughness using both crack tip opening displacement (CTOD) and J-integral parameters.
The T-L orientation appears to have the poorest resistance to tearing of the four normal cracking orientations for parent plate. The S-L orientation, however, has the worst toughness overall. Heat-affected zone toughness of both manual and submerged-arc welds is equivalent to parent plate. Submerged-arc weld metal toughness is comparable with the T-L orientation in plate material. Manual metal arc weld metal toughness is inferior to the toughness exhibited by submerged-arc and the four normal cracking orientations in parent plate. Increasing the test temperature from 370 to 540°C for manual metal arc weld metal appears to produce a distinct increase in resistance to ductile crack propagation.
Provided adequate thickness constraint is ensured, maximum load toughness determinations from the standard laboratory three-point bend geometry would appear to give conservative estimates of tensile instabilities under load control. The relevance of this behavior is discussed in terms of the use of single-parameter design curve methods for the estimate of tolerable flaw sizes in structural applications
stainless steel, welded joints, plate, bend tests, crack propagation, ductile fracture, fracture toughness
Paper ID: STP32563S