Going Beyond Larsen Miller

Stress Relieving is a vital process in the spring industry. It is a CTQ Factor and depends on several variables of interest. We initiate this project with the aim of creating better standards for Heat Treatment and to overcome the limitations of the much known Larsen Miller equation, which uses Time-Temperature to calculate Thermal Effect.  The extrapolation of equivalent recipes using Larsen Miller is often inaccurate. The objective of this project is to clearly determine the variables associated with stress relieving of springs and hence, to come up with a proven mathematical relation between these variables and residual stresses. This can be done by a methodology known as Design and Analysis of Experiments. It is an effective tool to make inferences about a process, by making purposeful changes to the influencing variables. This would enable us to calculate alternative high speed stress relieving recipes with better quality and time efficiency.