Abstract
This paper addresses the relationship between surface integrity and fatigue life of hard turned AISI 52100 steel (60-62 HRC), with grinding as a benchmark. The impact of superfinishing on the fatigue performance of hard turned and ground surfaces is also discussed. Specifically, the surface integrity and fatigue life of the following five distinct surface conditions are examined: hard turned with continuous white layer, hard turned with no white layer, ground, and superfinished hard turned and ground specimens. Surface integrity of the specimens is characterized via surface topography measurement, metallography, residual stress measurements, transmission electron microscopy (TEM), and nano-indentation tests. High cycle tension-tension fatigue tests show that the presence of white layer does not adversely affect fatigue life and that, on average, the hard turned surface performs as well or better than the ground surface. The effect of superfinishing is to exaggerate these differences in performance. The results obtained from this study suggest that the effect of residual stress on fatigue life is more significant than the effect of white layer. For the hard turned surfaces, the fatigue life is found to be directly proportional to both the surface compressive residual stress and the maximum compressive residual stress. Possible explanations for the observed effects are discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 337-346 |
| Number of pages | 10 |
| Journal | Materials Science and Engineering: A |
| Volume | 459 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Jun 25 2007 |
Funding
The first two authors would like to acknowledge the support of the following people in this work: Dr. F. Hashimoto of Timken Research, Dr. Mahen Patel of Hardinge Inc. for providing collets, step chucks and advice, Mr. Jim Kasparik of Kennametal Inc. and Mr. Kenny Lanxton of Valenite Inc. for providing cBN inserts and tool holders, Dr. John McGraw of Carpenter Technologies for the raw material and Mr. Jeff Frim of Braddock Metallurgical for heat treatment. The research work performed at Oak Ridge National Laboratory was sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of FreedomCAR and Vehicle Technology Program, as part of the High Temperature Materials Laboratory User Program, Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the U.S. Department of Energy under contract number DE-AC05-00OR22725.
Keywords
- Fatigue life
- Hard turning
- Surface integrity