The engineers started closing the rollerdoor the moment they saw a foreigner walking toward them.
Standing around laughing in blue overalls and yellow hard hats, they went quiet the moment I started walking up the drive. I asked if I could take a peek behind the door. They said it was a secret.
Still, I managed to catch a glimpse of two floors’ worth of the 10-story-tall machine Beijing hopes will play a major role in driving China’s aviation and aerospace industries: an 80,000-ton closed-die hydraulic press forge.
Repeated requests for a tour of the forge were declined. Both Zhang Jian, the head of propaganda at Erzhong Group, the company that built and operates the forge, and Wang Yu, the secretary of the board of directors of Erzhong’s Shanghai-listed unit, said that the forge is “confidential.”
It’s not immediately clear what about the machine – which is painted green with Erzhong Group printed across it in red Chinese characters – is so secret.
The machine is the biggest of its kind in the world. The biggest forge in the U.S. can exert only 50,000 tons of pressure, and is operated by Alcoa AA +0.93% in Ohio. France has a 65,000-ton machine, and Russia has a machine capable of exerting 75,000 tons of pressure.
But the technology China is using is nothing new. It is based on modifications of Russian designs from the 80s, according to a person involved in the development process.
More sensitive is was China can potentially do with it.
Press forging involves shaping a piece of metal under high pressure by squeezing it into a mold. That alters the flow of the metal’s grain – its internal structure – allowing engineers to create stronger and lighter components than would be possible by just beating them into shape or welding them together. Greater pressure results in stronger components.
The Erzhong forge can exert up to 80,000 tons of downward pressure using five columns. Flipped upside down, it could lift China’s Liaoning aircraft carrier, with room to spare for a handful of submarines. Airbus is using the Russian forge to make landing gear components for the A380, the world’s biggest passenger plane. Having the world’s biggest forge should allow China to produce large components of higher strength than possible elsewhere.
The technology was pioneered during WWII by Germany, which didn’t have a sufficient supply of steel and so had to mold its air force out of more brittle, but lighter metals, according to Tim Heffernan, a writer who has researched the U.S. forge program. The end of the war brought the start of the jet age, and the U.S. government provided support for the building of forges around the country, so that the country was able to produce light planes that were sufficiently strong to withstand supersonic speeds.
Alcoa’s forge has been producing parts for Boeing and Airbus for decades. The company says it supplies almost all forged wheel and brake components for U.S. military aircraft and helicopters, including the F-35 Joint Strike Fighter, the U.S. military’s newest fighter jet.
Erzhong hasn’t explicitly said what the forge will be used for, but academics involved in its development process said there are potential military applications.
The first component produced by the forge at its official launch in April last year was the landing gear for the C919, China’s long-awaited and much behind schedule narrow-bodied passenger aircraft being built by the Commercial Aircraft Company of China.
