Arcaloy ER312 is a solid wire and is for welding dissimilar joints, in particular where there is a high carbon content. With its high potential ferrite content, greater dilution by a non-stainless steel base metal is possible. Multi-pass welds can have beads with low base metal dilution in them therefore having a very high in ferrite content. This high ferrite can become brittle at high temperature and even with a high interpass temperature for a long period of time. Its high chromium content gives scaling resistance up to about 2000ºF (1100ºC). Depending upon its form, Arcaloy ER312 can be used in the MIG or TIG processes. In the case of the MIG (GMAW), spray, pulse or short-arc modes of transfer are used depending on the gas used. With this process, shielding gases or argon with 1 or 2% oxygen are commonly used for 'spray' and a mixture of 90% helium - 7.5% argon - 2.5% carbon dioxide is used for 'short-arc'.
For TIG (GTAW), 100% argon or argon with some helium additions are used.