Light? Strong? Tough? Cheap? A new material developed in Korea promises all of the above, and could throw open wide doors in many industries, including small arms development.

The weight and efficacy of small arms is highly dependent on the materials used to make them. Lightweight materials like aluminum or polymer are used wherever possible, and only where they are absolutely needed, such as the pressure-bearing barrel and locking surfaces, are heavier materials like steel applied. A good material for small arms construction should be both light and strong, with a high specific strength, while also being ductile and tough. Beyond that, however, materials suitable for small arms production also need to be easy to work in multiple ways (suitable for stamping, machining, welding, forging, etc), and, perhaps above all, cheap. It's these last two requirements that exclude, with few exceptions, titanium, which is extremely strong and tough, from being a good material for this purpose.

Production process tests

In their experiment, the researchers melted about 40 kg (88 lb) of the steel alloy in an induction furnace with a protective argon atmosphere and cast it into a rectangular ingot, Kim reported. Following a homogenization treatment—1150°C (2102°F) for 2 hours—the ingot was hot-rolled into strips 3 mm (0.12 in) in thickness. The hot-rolled strips were cold-rolled into 1-mm (0.04-in) -thick sheets that were next annealed at 870 to 900°C (1598 to 1652°F) for 2 to 60 minutes. The sheets were then immediately water-quenched or rapidly cooled to 25°C (77°F).

"All the steps except for the casting are very similar to the existing processes for industrial sheet steel production," he noted.

Subsequent joining tests showed that "our steel can be welded by electrical resistance spot welding, laser welding, and argon TIG welding," Kim said.

He stressed that the team's B2-dispersion method is really more important than the new alloy: "Steel scientists all over the world can make many variants of our steel for their own applications based on the novel microstructure, which comprises a steel alloy matrix and intermetallic precipitates."

The Pohang University researchers are now working with the South Korean company Posco, one of the world's largest steel manufacturers, to scale up their technology.

"We are planning a mill trial production of our steel this year at Posco, not for direct commercialization but for checking possible difficulties that are frequently met during scale-up," he said. "If everything goes smoothly, you may see our steel on the market in two to three years."