AUSTENITIC STAINLESS STEEL WELD MATERIALSnA DATA COMPILATION AND REVIEW

摘要

Data on austenitic stainless steel weld materials was com¬piled and reviewed to provide a central data source for additional, more extensive analysis of the effects of LMFBR service conditions on weld deposited metal. Mechanical property (tensile and creep-rupture) data generated in the HEDL Weldment Program is given in conjunction with a general review of weld metallurgy, including the role of ferrite, ferrite measurement, hot-cracking mechanisms, thermal effects and mechanical properties. A limited analysis of these data showed that:n1. Irradiation effects in weld materials are generally con¬sistent with trends established for wrought stainless steels, but, due to the higher initial strengths, the weld metal tends to ex¬hibit a lower damage accumulation rate.n2. A useful rule for welding structures intended for ele¬vated-temperature service is that the weld-deposit ferrite levels be restricted to <10% and generally minimized to a degree con¬sistent with preventing hot-microfissuring. Then mechanical pro¬perties of austenitic stainless steel welds depend largely on the austenite matrix rather than on the second-phase ferrite.n3. Specimens taken from multiple-pass weldments usually exhibit high tensile yield strength and low ductility compared to the wrought parent materials. Although the presence of ferrite may contribute a small strength increment, the major increase is due to weld-induced prestrain and residual stress. High tensile yield strengths and low ductilities are largely recoverable by post-weld annealing.