Why is it called Wumeng Iron Army? What's the history?

An artillery regiment of the Chengdu Military Region that has gone through the baptism of war is known as the "Wumeng Iron Army." The artillery regiment became a model for the entire army in 1998. In 2000, this regiment-level unit made another first-class meritorious service.

It’s just an honorary title, just like "Steel Seventh Company" or "Great Service Company X"