INFLUENCE OF CHROMIUM ON THE MECHANICAL-PROPERTIES AND MICROSTRUCTURE OF WELD METAL FROM A HIGH-STRENGTH SMA ELECTRODE

In the present work, the influence of Cr on mechanical properties and MiCrostructure of weld metal from a high-strength SMA electrode is analyzed by considering 12 experimental low-alloy low-hydrogen iron powder AWS E10018, E11018, E12018-M type covered electrodes. These electrodes were manufactured to obtain in the weld deposits Cr contents ranging from 0 to 1.8%, with two different Mn levels for each Cr content, maintaining the amount of other elements at a fixed value. All-weld-metal specimens and production-type single V-groove welds were mechanically tested in the as-welded and stress-relieved conditions, and a metallographic study was conducted. Chromium was found to be deleterious to toughness with only a minor influence due to Mn variations. A postweld heat treatment led in all cases to a reduction of toughness. Increasing Cr content in the welds produced, a higher proportion of acicular ferrite and a general refinement of the microstructure.