Residual Stress After Surface Hardening – An Explanation of How Residual Stress Is Created
L. Markegård, H. Kristoffersen:
RESIDUAL STRESS AFTER SURFACE HARDENING – AN EXPLANATION OF HOW RESIDUAL STRESS IS CREATED,
New challenges in heat treatment and surface engineering – conference in honour of prof. Božidar Liščić (09 – 12 June 2009, Dubrovnik – Cavtat, Croatia)
Driving forces behind the rise of residual stress are defined as well as basics that Core expansion is due to its average temperature and that forces within the part always have to balance, creating stress and reaction stress. Thermal and transformation strain vs. temperature curve are used to explain the process. An Elongation Potential is defined at a time when the plastic elongation of the Surface Layer is at its maximum. At this time the influence of process parameters are discussed. It is mentioned how we can understand results from Satoh tests in this context. Simulations are run with Sysweld on a piece at 4 different process conditions and material properties selected to highlight the conclusions.