Measurement and correction of residual stress gradients in aeronautical gears after various induction surface hardening treatments

Abstract Surface hardening is used in the aerospace industry to increase the fatigue life of critical structural components. Processes such as induction hardening are gradually replacing traditional non-environmental friendly surface treatments. Modern induction generators allow simultaneous heating with medium and high frequencies. A large range of process parameters are then available and may be varied to obtain a given hardened depth but with different residual stress distributions. In this paper, residual stress and microhardness gradients are measured in spur gears after four different types of induction surface treatment. An accurate methodology is proposed to measure and correct XRD results for layer removal and X-ray elastic constant variations from case to core. The results indicate that induction parameters have a significant effect on the residual stresses and that the best type of treatment could be contour hardening with a significant preheating and a final dual-frequency heating. The propose methodology could be adapted for measurements in other complex parts presenting deep microstructural and residual stress gradients.

[1]  W. P. Evans,et al.  Mathematical Correction for Stress in Removed Layers in X-Ray Diffraction Residual Stress Analysis , 1958 .

[2]  H. Danninger,et al.  Influence of surface residual stresses on gigacycle fatigue response of high chromium cold work tool steel , 2008 .

[3]  P. Bocher,et al.  Computational quantification and correction of the errors induced by layer removal for subsurface residual stress measurements , 2012 .

[4]  M. Prime.  Cross-sectional mapping of residual stresses by measuring the surface contour after a cut , 2001 .

[5]  Alexander M. Korsunsky,et al.  Residual stresses in induction-hardened gear teeth mapped by neutron diffraction , 2002 .

[6]  S. L. Semiatin,et al.  Induction Heat Treatment of Steel , 1986 .

[7]  Teresa Maria Berruti,et al.  X-ray residual stress measurement on mechanical components with high curvature , 2003 .

[8]  Yang-ming Chang,et al.  Residual stress measurement by X-ray diffraction , 1972 .

[9]  Valery Rudnev,et al.  Handbook of Induction Heating , 2002 .

[10]  A. Tjernberg.  Fatigue lives for induction hardened shafts with subsurface crack initiation , 2002 .

[11]  G. A. Webster,et al.  Residual stress distributions and their influence on fatigue lifetimes , 2001 .

[12]  B. Höhn,et al.  Influence of shot peening on bending tooth fatigue limit of case hardened gears , 2002 .

[13]  G. Beck,et al.  Prediction of residual stress and distortion of ferrous and non-ferrous metals: Current status and future developments , 2002 .

[14]  J. Hoffmeister,et al.  Residual Stress Prediction for Dual Frequency Induction Hardening considering Transformation Plasticity during Austenitization , 2012 .

[15]  Paul S. Prevéy,et al.  X-RAY DIFFRACTION RESIDUAL STRESS TECHNIQUES , 1986 .

[16]  M. N. James,et al.  Residual stresses and fatigue performance , 2007 .

[17]  P. Prevéy,et al.  X-RAY DIFFRACTION CHARACTERIZATION OF THE RESIDUAL STRESS AND HARDNESS DISTRIBUTIONS IN INDUCTION HARDENED GEARS , 1995 .

[18]  P. Vomacka,et al.  Influence of process parameters for induction hardening on residual stresses , 2001 .

[19]  Paul S. Prevéy,et al.  CURRENT APPLICATIONS OF X-RAY DIFFRACTION RESIDUAL STRESS MEASUREMENT , 1996 .

[20]  D. Coupard,et al.  Residual stresses in surface induction hardening of steels : Comparison between experiment and simulation , 2008 .

[21]  Srečko Glodež,et al.  Computational model for the analysis of bending fatigue in gears , 2002 .