Residual stress analysis of gray cast iron manufacturing processes

Abstract

ABSTRACT Much research has focused on residual stress detection, analysis and elimination for alloy materials. There is however limited work considering residual stress in gray cast iron materials (HT200, 250, 300, 350) which are commonly used in heavy machine tool components. Herein an experimental program is undertaken to quantify the influence of typical machine tool production processes (casting, treatments, machining) on component residual stress. In addition, for a select component element (a guideway mounting surface), an extended measurement program tracks residual stress and surface deviations over a two-year period, quantifying the time-dependent behavior of production-induced stresses during initial in-service conditions. The experimental program establishes the relationship between material carbon content and component residual stress, with greater carbon content resulting in less residual stress. For the aging treatments (heating, vibration, natural aging), the program quantifies and ranks the achievable stress reductions (68.74%, 36.83%, 29.1%, respectively). Finally, the extended measurement program demonstrates that within 2 months of production, greater than 99% of process-induced residual stress has been released and surface deviation is less than 0.5 μm per month.