November_December_2021_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 2 1 1 8 approach and procedures used at Dav- enport that had served to satisfy auto- motive customers such as Ford. The original workplan for the launch of Alcoa Tennessee had been laid out to support the launch of the 2017 Super Duty, with delivery of the first coils to Ford’s Kentucky Truck Plant in February 2016. But the addi- tional volume requirements for the F-150 simply could not be met with- out the new Tennessee capacity. Ford made it clear it would not accept the loss of a single production unit in what would be the most scrutinized launch in a century. Filling the production gap became the focus of an intense team effort, followed at the highest levels of management of both companies. The hard reality was that there was no way to change the equipment ready date (ERD) of April 15, 2015. And the ERD was simply the starting point of the qual- ification work. Qualifying 6xxx ABS is complex and time consuming because it covers several long lead time process- es, such as confirmation of the natu- ral aging behavior, structural adhesive bonding performance, and the prove- out runs at the stamping plants. Further, in Alcoa Tennessee’s case, the metal destined for structural- ly bonded parts needed to be finished at Davenport, from which the test sam- ples had to be prepared and then put through weekslong adhesive durability testing. In addition, the affected stamp- ing plants needed to run production trials for each gauge and alloy combi- nation—and do so during the launch ac- celeration period. All of this preparation work required months of intense coop- eration between the two companies. To save time, the two parties agreed to follow the same accelerated qualifica- tion process used by Davenport, using the equipment verification coils as the qualification coils, precluding any sec- ond guessing of production processes. By focusing on a list of parts that would not require pretreatment, the fastest schedule would make the first produc- tion coils available for delivery by the end of August 2015, about four months past the crossover point between de- mand and capacity. Novelis was in a better position than Alcoa at this point. It had some open capacity in Kingston, Ontario, for thin-gauge skin parts and it could con- vert some 5xxx parts to batch anneal, as long as they did not require the surface pretreatment that was part of the new integrated lines. Other than adding the new process routes to the qualification process, the increased volume could be contained within the plant’s existing infrastructure. Alcoa’s situation was more diffi- cult because its auto body sheet (ABS) capacity was sold out, and additional volume depended on the conversion of its North Plant. The facility had origi- nally opened in 1942 to produce aircraft sheet for WWII, followed by a wide vari- ety of sheet and foil products until the mid-1980s. In 1987, the plant had com- pleted a massive modernization to pro- duce can body stock. Its streamlined process and extremely efficient three- stand continuous cold rolling mill pro- duced more than 500,000 metric tons of 3104-H19 aluminum sheet every year for almost 30 years. The automotive expansion an- nounced in 2013 was a complete trans- formation that dwarfed those that had taken place in Davenport or Oswe- go, plants that had either produced or rolled aluminum ABS for decades. Switching from can body stock to ABS would touch every aspect of the pro- duction path, from the melt shop to the continuous heat treat line to cus- tomer-facing business systems. The only missing component would be the surface finishing that would contin- ue to be done in Davenport. Compli- cating matters, the planned heat treat line was not a simple copy of the new Davenport line, but a modified de- sign with increased capacity. Success would require an active collaboration between Ford and Alcoa’s entire auto- motive business, including the Alcoa Technical Center in Pittsburgh, the Au- tomotive Customer Center in Farm- ington Hills, Michigan, and Davenport Works in Iowa. A number of Davenport employees familiar with ABS relocated to Tennessee, among them Leslie Shu- man who joined the effort as director of operations readiness, having overseen the launch of the new Davenport lines. ALCOA RAMPS UP VOLUME The Tennessee can stock flow path depended on recycled cans, while ABS is rolled from alloys with much less tol- erance for impurities. Alcoa and Ford had agreed that their allocation of scrap from Ford’s stamping plants would be returned to Tennessee in a closed-loop arrangement. The Tennessee ingot/ can recycling manager Johnny Kincaid quipped, “We used to call it can rec, now it’s car rec.” The North ingot plant was converted to low head compos- ite casting tools to increase productiv- ity and reduce scrap losses, with ingot widths from 1600 to 2030 mm to cover the product range ordered by Ford. Tennessee has some of the larg- est continuous pusher furnaces in the world, capable of holding 48 ingots. These furnaces would prove critical to the quality and consistency require- ment for high-volume ABS. Despite this being the first time Alcoa produced ABS in pusher furnaces, homogenization of the ingots caused no major problems and the North Plant was ingot qualified for Davenport in November 2014. Build- ing on that success, Davenport would later convert to pushers. Perhaps the key piece of equip- ment in any aluminum rolling opera- tion is the hot mill. Tennessee’s 1940s vintage five-stand continuous mill had been rebuilt in 1990 as part of the can stock modernization. The chief require- ment remaining was to specify the met- allurgical parameters for 6xxx alloy ABS, such as target temperatures and reduc- tion schedules. Tennessee Operations hired Ryan White, Davenport’s hot mill metallurgist, to develop the practices necessary to make a product transpar- ent to Ford’s manufacturing process, matching the strength, formability, surface quality, and dimensional tol- erances of the Davenport product. As the effort evolved, the process expe- rience of Tennessee in producing can body stock proved valuable because controlling temperature, deformation schedules, and surface are key to both products. White brought the quality