College - Author 1
College of Engineering
Department - Author 1
Materials Engineering Department
Degree Name - Author 1
BS in Materials Engineering
College - Author 2
College of Engineering
Department - Author 2
Materials Engineering Department
Degree - Author 2
BS in Materials Engineering
Date
6-2023
Primary Advisor
Blair London, College of Engineering, Materials Engineering Department
Abstract/Summary
Vertical ring rolling is a forging process which forms seamless metal rings through applying a large force at elevated temperatures onto component materials stabilized by cylindrical mandrels. Carlton Forge Works, a company which produces rings of superalloy materials such as INCO718 and 718Plus, is experiencing a consistent failure of mandrels due to extreme conditions. An analysis of the lifetime (bulk material, heat treatment, and use) was performed, which aided in the identification of process variables tied to mandrel failure. Experiments were formed surrounding three variables of the mandrel heat treatment: Austenitization temperature, quenching temperature, and tempering conditions, with the goal of analyzing the degradation of mandrels prior to failure with hardness measurements. Rockwell Hardness C (HRC) was used in each of the three experiments. The first experiment assessed incomplete austenitization due to overcrowded furnaces at 1400˚F and 1550˚F. Secondly, quenching for 10 minutes at 70˚F, 100˚F and 150˚F, was performed to simulate quench vat conditions. Finally, extra tempering at 300˚F, 400˚F, 500˚F, 570˚F, 700˚F, 900˚F and 1400˚F was performed to replicate over-tempering of the mandrels during rolling. Hardness degradation below the HRC range of superalloy rings (35-40 HRC) was used to numerically fit the lifetime of components and propose solutions for mandrel failure.
URL: https://digitalcommons.calpoly.edu/matesp/265