Control of scale formation and removal during continuous processing

Principal investigator: Brian Gleeson

University: University of Pittsburgh

Industry partner: ATI Specialty Rolled Products

Allegheny Technologies Incorporated (ATI), headquartered in Pittsburgh, is a longstanding global manufacturer of technically advanced specialty materials and complex components. ATI recently commissioned a state-of-the-art Hot-Rolling and Processing Facility (HRPF), a $1.2 billion investment to position the company as a global leader in the production of specialty flat-rolled products. The HRPF has allowed ATI to add new advanced alloys to its portfolio, including ATI 6230TM, a Ni-based superalloy designed for high-temperature applications. However, the secondary processing of this and other advanced superalloys made possible through the HRPF have introduced unforeseen challenges that can affect product yields and, ultimately, market competitiveness. Specifically, certain coil products exposed to a gas-fired continuous-anneal furnace atmosphere can be left with an unwanted, green-tinted surface at the completion of the descaling stages.

The focus of this study will be to better understand the kinetics and structural phases associated with this green-tint formation by developing a laboratory-scale testing procedure at the University of Pittsburgh that replicates the tint-product formation behavior found in practice. The understanding gained will be used to formulate a tractable descaling procedure that maps the thermal-exposure history during continuous annealing to descaling response. Included in this study is the response to acid pickling formulations that are meant to result in clean final products. The proposed project is fully aligned with the goals of the Manufacturing PA Innovation Program by leveraging university expertise and capabilities to advance Pennsylvania-based manufacturing. Moreover, insights gained from this university-industry collaboration will be applied to the processing of current and future superalloys, helping to unlock new possibilities within the markets that ATI serves.