Large Forgings: Microstructural Evolution and Residual Stresses Due to Quenching Treatments-A Combined Numerical and Experimental Approach

• Published in: Materials performance and characterization 2014-12, Vol.3 (4), p.118-136
• Main Authors: Boniardi, Marco, Guagliano, Mario, Casaroli, Andrea, Andreotti, Riccardo, Ballerini, Filippo
• Format: Article
• Language: English
• ISSN: 2165-3992; 2379-1365; 2165-3992
• DOI: 10.1520/MPC20130089

Based on numerical and experimental data, an FEM model was implemented to simulate quench treatments on large forging components. After experimental validation of convection coefficient laws between water and component surface, time-temperature curves were determined for a large forged piece for different corss section of the component itself. Then superimposing these curves to the continuous cooling transformation diagram for the material, it was possible to identify the microstructural constituents of the steel after quenching. The component residual stress field was obtained by implementing the volumetric expansion law due to the phase transition during cooling. The ability to simulate the heat treatment of heavy size parts must be considered very useful due to quickly managing of all variables that govern the problem (initial and final temperatures, holding times, quenching mode, size, and geometry of components) and the possibility to predict final characteristics of the workpiece.