Stainless steel producer, machine builder converge engineering talents to commission multiple processing lines
Above: Fagor Arrasate lines (like slitting, shown) typically process several hundred thousand tons per year at North American Stainless’ main plant and service centers.
Stainless steel producer, machine builder converge engineering talents to commission multiple processing lines
April 2018 - It takes some time to prove that a product or service works as intended, without defect, and in a manner that is repeatable and effective.
North American Stainless has developed a long-term partnership with Fagor Arrasate because the two companies are able to work together to engineer and customize metal processing equipment that performs cleanly, safely and efficiently on high volumes of material.
“We are the largest stainless producer in the U.S. with the largest melt shop production,” says Ignacio Pascual, manager of marketing and product development at North American Stainless (NAS). Its melt shop capacity is 1.4 million tons per year; hot-rolled coil production capacity is 1.2 million tons; and cold rolling capacity approaches 1 million tons. “The totals produced depend on product mix,” says Pascual. “Several hundred thousand tons a year are processed through Fagor lines,” he adds, including shearing, cut-to-length, slitting and multi-blanking equipment.
NAS is a subsidiary of Acerinox SA of Spain, which also owns Columbus Stainless in South Africa and Baru Stainless in Malaysia. Acerinox founded NAS in 1990 as a joint venture with an American partner. “It was built to produce sheet and coil 60 inches wide because, at the time, nobody in the United States produced stainless steel coils that were 60 inches wide,” Pascual says.
“We aren’t buying off a shelf. It’s all custom to what we need,” Ignacio Pascual says of processing line selections.
Within a few years, the American partner sold its shares back to Acerinox. Today, NAS has grown “to the point where we are the largest producer of stainless flat-rolled (coils, sheets and plates) and long products (bars, angle bar, wire rod and rebar) in the United States.”
Acerinox’s long relationship with Fagor Arrasate has had a bearing on the development of NAS. “We did a backward integration starting with cold rolling. In 2003, we added long products. And we added lines as capacity grew,” says Pascual.
“When we started building the plant [in Kentucky], we could refer to Acerinox’s experience with Fagor. We had the benefit of hindsight already in place at our Spanish mills, which is one of the reasons we started buying and installing Fagor equipment here.”
Design fluidity
“One of the things the operators like and the management team likes is that these are proven lines. We took general designs from other locations and then turned to Fagor’s engineering department to say, ‘We like how this line works in Spain but we wanted to incorporate design changes in some areas,’” says Pascual.
Over the years, “the safety aspects of many lines have evolved, as has productivity with new PLCs and automation.”
Fagor has a large engineering department, he says, including electrical, mechanical, hydraulic and pneumatic engineers. “We aren’t buying off a shelf. It’s all custom to what we need. When we are going through what features we want, we can ask them for particular solutions. Because they are global, they may have already designed something like that for another customer and can transfer some of those ideas to us. They have a lot of know-how and are able to source ideas from anywhere.”
Integrated producer
NAS operates a total of nine Fagor stainless steel processing lines across its main plant in Ghent and service centers in Wrightsville, Pennsylvania; Pendergrass, Georgia; Guelph, Ontario; and Apodaca, Mexico.
The service centers perform shearing, slitting, blanking and multi-blanking. There are industry-specific processes, too. For example, the plant in Pennsylvania blanks small panels for the sides of washing machines.
“The lines we commission for the mill are designed for volume. The cut-to-length lines at the mills cut larger sheets at high volume,” according to Pascual. “At our service centers, we perform multi-blanking in Mexico and Pennsylvania. The design of each line is different,” he says. NAS indicates to Fagor the intended end markets for each line. For example, its multi-blanking line serves the appliance sector.
A 10th line has been ordered and will be installed in Ghent later this year. Pascual describes it as a coil builder line. “You take a large coil, thread a leader strip of secondary material and weld that to another coil so that when you are rolling coil and reducing gauge, you can roll the whole coil and cut off the leader strip. It’s a way to maximize the amount of stainless you are rolling from each master coil,” he explains.
NAS service centers perform shearing, slitting, blanking and multi-blanking. The plant in Pennsylvania blanks small panels for the sides of washing machines.
Maximizing yield
Phil Conway, director of sales for the steel division of Fagor Arrasate USA in Willowbrook, Illinois, expands on what this new line actually does.
“The buildup line is designed for an internal process in the mill,” he notes, not one performed for the sake of end-use applications.
The next step down the line is the Z mill, which is a reversible cold-rolling process. “In order to save scrap, we weld leader strips on the heads and tails of coils. The material between the work rolls on the cold mill and mandrel, say 30 feet of material, normally never gets processed because you need tension on the rolls.”
However, using the coil buildup line, “we weld reusable material on each end of the coil so it can be cut off and resent to the beginning of that line,” Conway says. The leader strips can be used a dozen times before it’s sent back to the furnace for remelt.
A vacuum lifter places leader strip at the coil head, straightens the leader strip, then unwinds the coil, welds it and winds to the end of coil, where another strip is welded to the tail end. The coil, now with both head and tail, is rewound and moved to the cold mill.
Conway says NAS has traditionally used leader strips to get more yield out of coils through annealing lines and cutoff machines. The buildup line “streamlines that early on and not in annealing. It also improves the quality of the leader strips because they are not being annealed. [Annealed strips often] come out with wicked waves.” By attaching strips at the beginning of the rolling mill, the heads and tails won’t be heat affected so, after being sheared from the master coil, they are just sent back to the mill’s front end. “A significant amount of prime material is saved,” which can go directly to end users.
Conway says the coil buildup line, as it’s dealing with mill master coils, will be a long line installed parallel to an existing annealing/pickling line.
Control and safety
NAS, says Pascual, puts a premium on reliability with equipment. “That is toward plant productivity, which impacts our workers—a certain portion of what they earn is tied to production. If an employee works on a line that has few breakdowns, they are happy with the line.”
The Fagor equipment, he continues, is “really well built—that is our experience at Acerinox and at NAS. They have features that are important to us. One is automation. All the lines we installed have a high degree of automation, such as variable frequency drive systems, PLC control, instrumentation that allows us to control yields and dimensions. The amount of information we get [from the machinery] is impressive.”
Even more important, Pascual adds, “is we place a high premium on safety. As a large industrial company with a lot of machines, it is a very high priority. The Fagor lines have a lot of safety features. I assume a lot of [equipment manufacturers] include those but the way that they install it here, with barriers, doors and gates, an operator cannot get into the line where he can get hurt.”
He notes that access is always at floor level. “There are no catwalks or stairs that operators have to climb up. It would be almost impossible to fall into a looping pit. Even to an extent that a line is set up manually, and a barrier is open, the system warns the user with flashing lights.”
A bonus for NAS is that Fagor’s service technicians are relatively close by. “We feel it’s a big advantage that there is a U.S.-based service management division. If we have a problem with a machine, or want to try something new—like running a different grade and determining if it will cut properly—they help us on a real-time basis with service and support. We are known for being a cost-efficient producer,” says Pascual, “so the choice of production equipment is very important.” MM
