Abstract
In this study, the corrosion resistance of type D 308 L and D 316 L weld metals was evaluated by test in boiling solution of 65% nitric acid.
The experimental results are as follows.
(1) Chromium is beneficial to decrease corrosion rate. Manganese and Nickel have no effect.
(2) The fully austenitic weld metal has a stronger corrosion resistance than the partially ferritic weld metal as welded condition, but adverse in weld metals with sensitizing heat treatment.
(3) Weld metals aged at temperature of 650 to 750°C have remarkably high rates of corrosion attack.
(4) In the partially ferritic weld metal, chromium carbide (Cr 23 C 6) precipitates in the grain boundary and interior of ferrite-phase ane the carbide precipitation in the austenitic grain boundary is extremely reduced, so the corrosion resistance is improved.
