Prediction of High-Frequency Induction Hardening Depth of an AISI 1045 Specimen by Finite Element Analysis and Experiments

Abstract

A high-frequency induction hardening analysis method was established based on electromagnetic-thermal translation analysis (cosimulation). The same conditions as those used in the experiment were applied to the high-frequency induction hardening analysis, using the temperature-dependent material properties of AISI 1045. Cooling parameters coincided with the cooling conditions of water in the analysis. The hardening depth of the high-frequency induction-hardened specimen was measured using a micro Vickers hardness tester, and the hardening depth and hardening pattern were verified in terms of the resulting metallurgical structure. Experimental results were compared with those obtained from finite element analysis (FEA) simulations. The hardening pattern was confirmed with AISI 1045 heating to temperatures above 746 degrees C, corresponding to the A2 transformation point, and then cooling to below 200 degrees C. There was good agreement between experimental and FEA results for the heating and cooling temperatures, as well as the hardening depth and hardened area. When AISI 1045 was heated above the A2 transformation point, its structure transformed from ferrite to austenite; thus, it changed from a magnetic material to a non-magnetic material. FEA of the magnetic flux density and Joule heat density during the heating period revealed that high-frequency induction hardening is favorable for surface hardening.