THE EFFECT OF WELDING PARAMETERS ON HIGH-STRENGTH SMAW ALL-WELD-METAL- PART-2 - AWS E10018-M AND E12018-M

Three AWS A5.5-81(1) all-weld-metal test assemblies were welded, each with one of E10018-M and El 201 8-M type electrodes from standard prod uction batches, varying the welding parameters, in such a way as to us e high heat input and high interpass temperature (hot), medium heat in put and medium interpass temperature (medium) and low heat input and l ow interpass temperature (cold). Mechanical proper ties and metallogra phic studies were performed in the as-welded condition. The Following results were achieved: the three all-weld-metals from E10018-M electro des satisfied the AWS requirements, despite the fact that the measured properties varied slightly. With the E12018-M electrodes, the medium test specimen was the only one that fulfilled the AWS requirements. Th e cold test specimen showed a yield strength that exceeded the maximum requirement of the norm and the hot specimen did not achieve the mini mal value of tensile strength. AII the test specimens satisfied elonga tion and toughness requirements. Metallographic studies showed that as the heal input increased, the percentages of recrystallized zones inc reased, the grain size became larger and, in the columnar regions, the re was a small increment of acicular ferrite and ferrite with second p hase at the expense of primary ferrite. These results showed the E1001 8-M alloy to be markedly less sensitive to the variations of heat inpu t than the E12018-M. With the E12018-M electrode, it is necessary to w eld under strict control and with precise conditions, as found for E11 018-M electrodes in Part 1 of this work, in which the same study was p erformed with the latter type of electrode.