Measurement and simulation of residual stresses in grey cast iron as a function of shake-out temperature

Abstract

ABSTRACT A high shake-out temperature after casting is beneficial from a production point of view due to the need of a shorter cooling line in the foundry. However, a higher shake-out temperature might also lead to increased residual stresses due to faster cooling. In order to get a good agreement between simulated and measured temperature curves it is important to adjust material data and heat transfer coefficients accordingly. A reduction of the thermal conductivity of the sand by 25% and a drastically increased HTC were the main adjustments. From the residual stress simulation, the most important lesson learned was the necessity to include the sand in the calculation. Especially internal sand cores can greatly restrict the thermal contraction of the casting. After this fine-tuning of the simulation a good agreement with measurements was obtained. It could be verified that an increased shake-out temperature will lead to significantly increased residual stresses.