李旻的回答：

碳钢锻件，为美国钢铁材料标准，主要用于阀门。国内有这种材料，主要为部分锻造厂生产，原料以替代品为多；部分钢厂可以生产锻坯，只有个别钢厂可以生产成分和性能满足美标要求的轧材。

青春女孩的回答：

应该是 a105m吧 standard specification for carbon steel forgings for piping applications this specification2 covers forged carbon steel piping components for ambient- and higher-temperature service in pressure systems. included are flanges, fittings, valves, and similar parts ordered either to dimensions specified by the purchaser or to dimensional standards such as the asme and api specifications referenced in section 2.