Carbon steel forgings, manufactured in accordance with ASTM A105, are generally used for piping applications. These forged carbon steel piping components (including flanges, fittings, and valves, etc) are used for ambient- and higher-temperature service in pressure systems. The A105N, which is designated with a suffix “N”, denotes that the A105 forging shall be furnished in normalized condition. If the forgings are used for piping applications of ASME BPVC or ASME B31, the material shall be its identical equivalent of SA-105 or SA-105N. In short, the heat treatment of normalization distinguishes A105N from A105, or SA-105N from SA-105.
Although normalization is a prevalent heat treatment procedure for ASTM A105 forgings, it is not a mandatory requirement except for the following piping components: