Clean steel production of AMS 6308 with inclusion entrainment prediction through modern process monitoring

This project proposes to evaluate the transition of traditionally double-melted Alloy 53 to a double-refined ESR-VAR processing to providing superior cleaning of the alloy. In this case, Alloy 53 electrodes will generated by state of the art, clean air-melt processing prior to being put through the rigorous ESR-VAR process leading to improved quality at a cost neutral rate. In so doing, we will introduce an advanced VAR process monitoring tool, VARmetric™ capable of identifying final melt conditions that lead to the creation of solidification defects or that would lead to exogenous material inclusions in the final ingot. Here we propose to evaluate the efficacy of these technologies to drive overall processing conditions to favor defect free ingots of Alloy 53. This includes simultaneously creating melting conditions that provide for stable solidification profiles while not creating the turbulent flow necessary to entrain exogenous material in the interior of an ingot. Phase 1 of this project consists of two main goals: 1) To characterize the inclusion content in Alloy 53 under current production methods by determining the size, type, distribution, and locations of inclusions in double vacuum melt Alloy 53 material using the ASTM E45 standard and to compare those with Alloy 53 generated from the double refining melt approach proposed here; and 2) to computationally simulate inclusion particle tracking in a VAR furnace operating without and with the application of external magnetic fields. By determining conditions that lead to turbulent flow, and then identifying applied fields effective at stabilizing the turbulent melt pool conditions, we can predict the uniform heat flux required to make defect free Alloy 53 under all conditions. During the Phase I Option, we will relegate these theoretical predictions into practice utilizing the research VAR located at Ampere Scientific. In this case, we will artificially introduce exogenous material (calcium-aluminate) into the interior of an electrode. During melting, the material will be released and will float on top of the melt pool.  These experiments serve several purposes: a) to further establish an ingot characterization standard with and without inclusion defects; b) to inform the monitoring and control of turbulent melt conditions that lead to entrainment; and c) to establish the efficacy of control of arc distributions leading to quality control increases. The overall goal of these studies is to prepare for industrial trials at Ellwood Quality Steels during a Phase II effort to evaluate the quality of the metal as compared to traditional processing techniques. The results provided here will provide the baseline for scaling the technology to commercial scale.