Holographic Determination of the Yield Strength of a Welded Stainless Steel Pressure Vessel.

摘要

The strength and toughness of a high energy rate formed (HERF'ed) stainless steel,as influenced by the heat input from a variety of welds,are being measured. Using holographic interferometry, a welded spherical pressure vessel constructed from HERF'ed stainless steel with a composition of 21percent Cr, 6percent Ni, 9percent Mn, 0.23percent N,balance Fe was examined. Holographic examination of the weld vicinity shows that plastic deformations in the heat affected zones reach a maximum at a distance of 5mm on either side of the weld,and tails off for another 20mm to zero strain. The yield and ultimate strengths of the heat affected zones,based on the thin wall relation and using the wall thickness just above the weld,is nearly that of the parent material. However,the mode of deformation indicates that if the heat affected zones were either of higher strength or narrower,the pressure vessel would be stronger. Several more vessels are being electron beam welded using different weld parameters,and these will be examined to determine how the strength of the vessel is affected. (ERA citation 02:003479)