Low-Cycle Fatigue Evaluation of Coke Drum Base Materials and Welded Joints - A Summary of OSU Research Project and Future Work

Abstract

Abstract Coke drums are critical units in the delayed coking process to produce lightweight oil products from heavy residual oil. The fulfillment of the designed coke drum lifetime is often obstructed by low-cycle fatigue damage over cyclic thermal and mechanical loading. Considering the tremendous cost of drum replacement and production loss due to shutdown, the coke drum lifetime extension is of great economic significance in the oil and gas industry. A research project regarding coke drum fabrication and repair was initiated in the Manufacturing & Materials Joining Innovation Center (MA2JIC) at the Ohio State University in 2016. The project includes two phases of work. The first phase of the study (2016∼2019) focused on the external weld repair of coke drum materials, while the ongoing second phase of the study (2019∼2023) addressed coke drum fabrication and repair. A novel low-cycle fatigue testing approach was developed using Gleeble thermo-mechanical simulator and was applied to evaluating the performance of coke drum base materials and welded joints under cyclic deformation. The project goal is to improve the fundamental understanding of materials and joint performance that allows the optimization of coke drum design, fabrication, and repair. In this technical paper, the key methodologies and achievements of the project will be introduced, and some future work will be proposed for the next step.