Comparison of Surface Characteristics and Thermal Residual Stress Relaxation of Laser Peened and Shot Peened AISI 4140

  1. Prof. Dr.-Ing Lothar Wagner Chairman of ICSP8
  1. Rainer Menig,
  2. Volker Schulze and
  3. Otmar Vöhringer

Published Online: 7 FEB 2006

DOI: 10.1002/3527606580.ch64

Shot Peening

Shot Peening

How to Cite

Menig, R., Schulze, V. and Vöhringer, O. (2003) Comparison of Surface Characteristics and Thermal Residual Stress Relaxation of Laser Peened and Shot Peened AISI 4140, in Shot Peening (ed L. Wagner), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527606580.ch64

Editor Information

  1. TU Clausthal, Institut für Werkstoffkunde und Werkstofftechnik, Agricolastr. 6, D-38678 Clausthal-Zellerfeld, Germany

Author Information

  1. Institut für Werkstoffkunde I, Universität Karlsruhe (TH), Karlsruhe, Germany

Publication History

  1. Published Online: 7 FEB 2006
  2. Published Print: 12 MAY 2003

ISBN Information

Print ISBN: 9783527305377

Online ISBN: 9783527606580

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Keywords:

  • laser peened AISI 4140;
  • shot peened AISI 4140;
  • comparison of surface characteristics;
  • thermal residual stress relaxation

Summary

Laser peening is a relatively new mechanical surface treatment which causes deep zones bearing compressive residual stresses. This is accomplished by applying shock waves to the material surface using short laser pulses. Quenched and tempered steel AISI 4140 was laser peened using a Nd:glass slab laser with a pulse energy of 25 Joule and a wavelength of 1053 nm. Afterwards the mechanically affected zones were analyzed according to their topography, residual stress state and work hardening state and compared to shot peened samples. It is well known that the effect of mechanical surface treatments strongly depends on the stability of the induced residual stress state. Therefore, annealing treatments at different temperatures and times were performed to analyze the thermal residual stress relaxation behavior. Using an iterative mathematical procedure based on a least squares algorithm the activation enthalpy for thermal residual stress relaxation was determined and the responsible mechanisms were identified. The results were evaluated according to the amount of cold work caused by the different surface treatments.