AWS G2.3M-G2.3:2012 pdf download.Guide for the Joining of Solid Solution Austenitic Stainless Steels
1.1 Scope. This guide presents a description of solid solution austenitic stainless steels and the most commonly used welding processes and procedures for joining these materials. The most commonly used welding processes, including shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), submerged arc welding (SAW), and flux core arc welding (FCAW), are discussed in detail; laser beam, electron beam, plasma arc,resistance, and braze welding are not covered in great detail.
The welding processes discussed in this guide include recommended welding parameters, filler metals, shielding gases,and fluxes. Procedure qualifications, inspection and repair considerations and methods, and cleaning and safety con-siderations are also discussed. Practical information has been included as figures, tables, and graphs that should prove useful for determining the capabilities and limitations in the joining of austenitic stainless steels. This guide does not address martensitic, ferritic, or duplex stainless steels.
1.2 Units of Measure. This standard uses both the International System of Units (SI) and U.S. Customary Units. The latter are shown with brackets ([ ]) or in appropriate columns in tables and figures. The measurements may not be exact equivalents; therefore, each system should be used independently.
ferrite. A solid solution phase with the body-centered cubic (BCC) crystal structure. The term "ferrite”" as discussed inthis document is“delta ferrite." The presence of ferrite during solidification increases resistance to weld metal solidi-fication cracking but can also promote formation of brittle intermetallics such as sigma phase during subsequent high temperature exposure. Delta ferrite forms during the solidification of molten stainless steels containing iron alloyed with ferrite-promoting elements including chromium, molybdenum, silicon, niobium, titanium, aluminum, vanadium,or tungsten.
heat tint. Also called discoloration. Any change in surface color from that of the unaffected base metal; usually associ-ated with oxidation. Heat tint may occur on the weld, weld heat-affcted zone (HAZ), or base metal as a result of heating from welding or other thermal processes. Heat tint colors may range from pale bluish-gray to deep blue, and from a pale straw color to a black crusty coating.
passivation. The chemical treatment of a stainless steel with a mild oxidant so as to remove free iron from the surface and speed up the process of forming. a protective/passive layer. However, passivation is not effective for the removal of heat tint or oxide scale on stainless steel.AWS G2.3M-G2.3 pdf download.