Rolling Contact Fatigue Life of Cavitation-Peened Steel Gear

Abstract

The purpose of this study is to investigate the effect of cavitation peening on the rolling contact fatigue life of steel gears. The steel rollers and gears cavitation-peened under different conditions were fatigue-tested using a roller testing machine and a gear testing machine. After the cavitation peening, the surface hardness and the surface compressive residual stress of the steel rollers and gears were increased. On the other hand, the surface roughness was not increased so much. As a result, the fatigue life of most cavitation-peened rollers and gears was longer than that of the non-peened ones. In particular, the fatigue life was significantly improved by using a modified nozzle for a high-speed water jet to obtain a greater peening effect. It is suggested from these that the cavitation peening is good for the increase in fatigue life of steel gears, because the peening effect is obtained with less increase of the surface roughness.

Fatigue Strength of Steel Rollers and Gears Treated by Cavitation Peening with Short Processing Time (A Case of Processing Time of 1 min and 5 min)

“…CP is effective for the increase in fatigue life of steel gears, because the increase in surface hardness and surface compressive residual stress is obtained with less increase in surface roughness (5) . Our previous study revealed that the fatigue life of cavitation-peened steel rollers increased with increasing processing time of the CP within a processing time of 30 min.…”

Rolling Contact Fatigue Life of Steel Rollers Treated by Cavitation Peening and Shot Peening

“…On the other hand, cavitation peening (CP), which does not require shots unlike SP, is a surface treatment method, and it can provide the increase in hardness and compressive residual stress near surface with less surface roughness change. Our previous study (2) revealed that the rolling contact fatigue (RCF) life of cavitation-peened rollers increased with increasing processing time of the CP within 30 min. Therefore, in this study, the steel rollers were treated by the CP and the SP to ensure the same surface roughness of the peened steel rollers, and their RCF tests were performed in order to investigate the influence of the CP and the SP on the RCF life of the steel rollers.…”

Improvement of the Fatigue Strength of Stainless Steel SUS316L by a Cavitating Jet with an Associated Water Jet in Water

“…Cavitation shotless peening can introduce compressive residual stress to mitigate stress corrosion cracking or to eliminate fretting fatigue, 8,12,14) and enhance the fatigue strength of metallic materials. 11,13,[15][16][17][18][19] In order to develop cavitation shotless peening for practical applications, it is very important to enhance the cavitation impact to achieve better results and shorten the processing time.…”

“…[8][9][10][11][12][13][14][15][16][17][18][19] A high-speed water jet with cavitation bubbles is called a cavitating jet. However, in this paper, since the jet is introduced into a water filled chamber, we call this "a cavitating jet in water".…”

“…However, cavitation impact can also be utilized to improve the surface in the same way as shot peening. [1][2][3][4][5][6][7][8][9][10] As shot are not required, the peening method using cavitation impact is called "cavitation shotless peening" [11][12][13][14][15][16][17][18][19] or simply "cavitation peening". 20) One of the major advantages of cavitation shotless peening is that the peened surface is very smooth compared with a shot peened one, as there are no collisions between solid materials.…”