2013 Volume 31 Issue 3 Pages 216-221
980 MPa grade Cr-Ni weld metal with martensite and retained austenite was produced by single-pass GMAW. Its impact behavior was evaluated using the Charpy impact test. It was found that (1) strain-induced martensite transformation from the retained austenite enhances the impact absorbed energy at various temperatures and contents of oxygen in weld metal; (2) increasing the oxygen content in weld metal reduces the impact absorbed energy; and (3) at 233K, strain-induced martensite transformation can change the fracture mode of the weld metal with extremely low oxygen content from brittle to ductile, but it has no such effect at higher oxygen content levels. Oxide promotes ductile fracture. An increase in the oxygen content lowers the vTrs.
