An ultrasonic vibration cavitation erosion experiment was performed to study the thermal effect during the erosion process. The ring affected zone was observed on the sample surface around the erosion pit at the incipient stage of the cavitation erosion. The results of the surface testing on roughness, hardness, and chemical composition proved that the zone was caused by thermal effect, and that the zone surface experienced a tempering process with the temperature higher than $300°C$. Numerical simulation results show that the high temperature domain in the bubble directly contacting the solid wall is a necessary condition for the occurrence of the tempering process on the zone surface, or the heat in the bubble can hardly be transferred to the solid wall under the effects of the great temperature gradient in the bubble and the quick cooling process in the water.

1.
Hammitt
,
F. G.
, 1980,
Cavitation and Multiphase Flow Phenomena
,
McGraw-Hill
,
New York
, p.
241
.
2.
Nowotny
,
H.
, 1942,
Destruction of Materials by Cavitation
,
VDI-Verlag
,
Berlin
.
3.
Gavranek
,
V. V.
,
Bol’shutkin
,
D. N.
, and
Zel’dovich
,
V. I.
, 1960, “
Thermal and Mechanical Action of a Cavitation Zone on the Surface of a Metal
,”
Fiz. Met. Metalloved.
,
10
, pp.
262
268
. 0031-9007
4.
Knapp
,
R. T.
,
Daily
,
J. W.
, and
Hammit
,
F. G.
, 1970,
Cavitation
,
McGraw-Hill
,
New York
.
5.
Wu
,
C. C.
, and
Robert
,
P. H.
, 1993, “
Shock-Wave Propagation in a Sono-Luminescence Gas Bubble
,”
Phys. Rev. Lett.
0031-9007,
70
(
22
), pp.
3424
3427
.
6.
Ying
,
C. F.
, and
An
,
L.
, 2002, “
High Temperature and High Pressure Distribution in Gas Bubbles Generated by Sound Cavitation
,”
Sci. China, Ser. A: Math., Phys., Astron.
,
32
(
4
), pp.
305
313
. 0031-9007
7.
Nishi
,
T.
,
Shibata
,
H.
,
Tsutsumi
,
K.
,
Ohta
,
H.
, and
Waseda
,
Y.
, 2002, “
Measurement of Thermal Diffusivity of Steels at Elevated Temperature by a Laser Flash Method
,”
ISIJ Int.
0915-1559,
42
(
5
), pp.
498
503
.
8.
Knapp
,
R. T.
, 1955, “
Recent Investigations of Cavitation and Cavitation Damage
,”
Trans. ASME
,
77
, pp.
1045
1054
.
9.
Plesset
,
M. S.
, and
Ellis
,
A. T.
, 1955, “
On Mechanism of Cavitation Damage
,”
Trans. ASME
,
77
, pp.
1055
1064
.
10.
Wang
,
Z. C.
,
Zhang
,
Y.
, and
Zhang
,
X. Q.
, 2001, “
Thermal Effect of Cavitation Erosion
,”
Chinese Journal of Materials Research
,
15
(
6
), pp.
287
290
.
11.
Gregory
,
E.
, and
Simons
,
N.
, 1958,
The Heat-Treatment of Steel
,
Pitman & Sons
,
London
.