French steelmaker Aubert & Duval have announced a new high purity steel alloy that could allow future firearms barrels to be stronger, be tougher, and last longer. The steel, called “ARMAD”, is a 3% chromoly steel made with a similar composition to their GKH (33CrMoV12-9) steel used for small arms barrels, such as those used on the FAMAS rifle. Where ARMAD differs is in how it is made, rather than what it is made from. Aubert & Duval has developed a very precise process that uses both electric arc furnace and laddle furnace stages, which results in very low levels of impurities – significantly less than 50 parts per million of phosphorous and less than 5 parts per million of sulfur. The high purity results in a steel with a finer and more uniform grain structure, which means it can be heat treated to higher hardnesses while retaining its strength – meaning gun barrels made out of the stuff should last longer, while being both stronger and tougher than those made of more conventional steels. A technical article describing the new steel and the process to make it has been published by Forge & Fonderie magazine, but Aubert & Duval provided an English language document to TFB for publication:
EDIT: Above link doesn’t work. Here is another link.
As this image shows, ARMAD’s refined process results in a much more uniform grain structure than other steel grades. ARMAD shown in the green box on the left, 32CrMoV12-10 on the right:
You can’t buy barrels made out of ARMAD just yet, but Aubert & Duval has sent material to several barrel manufacturers in both the United States and Europe for testing. Maybe someday, high hardness steels of this type will be standard for small arms barrels, who knows?