Underwater local dry laser welding of the tube-plate structure was performed first. The effects of laser power and welding speed on welding quality were studied. With the increase in the laser power or decrease in the welding speed, the melting zone (MZ) area and depth-width ratio of the welded joint increased, and metallurgical porosity also increased. When the laser power was 2 kW and the welding speed was 12 mm/s, a better metallurgical bond could be formed between the tube and plate, and there were fewer metallurgical pores in the welded joint. Due to a large amount of evaporation and ionization of water in the gap between the tube and plate, metallurgical pores formed in the welded joint. By adding a waterproof layer on the back of the substrate, the metallurgical porosity decreased from 2.1% to 0%. In order to investigate the influence of a water environment on welding quality, the in-air laser welding was performed. Compared to in-air welded joint, the MZ area, depth to width ratio, and grain size were smaller. The average microhardness of underwater welded joint was higher than that of in-air welded joint due to the refined crystalline strengthening. In addition, because the magnesium burning loss in an underwater environment was less than that in an in-air environment, the microhardness values at the top of the underwater MZ were similar to those at the bottom, while the microhardness values at the top and bottom of the in-air MZ were much different.

1.
L. E.
Ramírez Luna
,
A. Q.
Bracarense
,
E. C. P.
Pessoa
,
P. S.
Costa
,
G.
Altamirano Guerrero
, and
A. E.
Salas Reyes
, “
Effect of the welding angle on the porosity of underwater wet welds performed in overhead position at different simulated depths
,”
J. Mater. Process. Technol.
294
,
117114
(
2021
).
2.
L. G.
Han
,
X. M.
Wu
,
G. D.
Chen
,
Z. M.
Wang
, and
W. Y.
Fan
, “
Local dry underwater welding of 304 stainless steel based on a microdrain cover
,”
J. Mater. Process. Technol.
268
,
47
53
(
2019
).
3.
Y. H.
Shi
,
K.
Sun
,
S. W.
Cui
,
M.
Zeng
,
J. L.
Yi
,
X. Q.
Shen
, and
Y. Y.
Yi
, “
Microstructure evolution and mechanical properties of underwater dry and local dry cavity welded joints of 690 mpa grade high strength steel
,”
Materials
11
,
167
(
2018
).
4.
J.
Tomków
,
M.
Landowski
,
D.
Fydrych
, and
G.
Rogalski
, “
Underwater wet welding of S1300 ultra-high strength steel
,”
Mar. Struct.
81
,
103120
(
2022
).
5.
M. A.
Habib
,
H.
Keno
,
R.
Uchida
,
A.
Mori
, and
K.
Hokamoto
, “
Cladding of titanium and magnesium alloy plates using energy-controlled underwater three layer explosive welding
,”
J. Mater. Process. Technol.
217
,
310
316
(
2015
).
6.
Q. Z.
Wang
,
Z. X.
Zhao
,
Y.
Zhao
,
K.
Yan
, and
H.
Zhang
, “
The adjustment strategy of welding parameters for spray formed 7055 aluminum alloy underwater friction stir welding joint
,”
Mater. Des.
88
,
1366
1376
(
2015
).
7.
G. J.
Shannon
,
J.
Watson
, and
W. F.
Deans
, “
Investigation into the underwater laser welding of steel
,”
J. Laser Appl.
6
,
223
229
(
1994
).
8.
H.
Chen
,
N.
Guo
,
X. H.
Shi
,
Y. P.
Du
,
J. C.
Feng
, and
G. D.
Wang
, “
Effect of hydrostatic pressure on protective bubble characteristic and weld quality in underwater flux-cored wire wet welding
,”
J. Mater. Process. Technol.
259
,
159
168
(
2018
).
9.
Z. Y.
Huang
,
Z.
Luo
,
S. S.
Ao
, and
Y. C.
Cai
, “
Underwater laser weld bowing distortion behavior and mechanism of thin 304 stainless steel plates
,”
Opt. Laser Technol.
106
,
123
135
(
2018
).
10.
G. J.
Shannon
,
W.
Mcnaught
,
W. F.
Deans
, and
J.
Watson
, “
High power laser welding in hyperbaric gas and water environments
,”
J. Laser Appl.
9
,
129
136
(
1997
).
11.
X. D.
Zhang
,
E.
Ashida
,
S.
Shono
, and
F.
Matsuda
, “
Effect of shielding conditions of local dry cavity on weld quality in underwater Nd:YAG laser welding
,”
J. Mater. Process. Technol.
174
,
34
41
(
2006
).
12.
N.
Guo
,
X.
Xing
,
H. Y.
Zhao
,
C. W.
Tan
,
J. C.
Feng
, and
Z. Q.
Deng
, “
Effect of water depth on weld quality and welding process in underwater fiber laser welding
,”
Mater. Des.
115
,
112
120
(
2017
).
13.
X. D.
Zhang
,
W. Z.
Chen
,
E.
Ashida
, and
F.
Matsuda
, “
Relationship between weld quality and optical emissions in underwater Nd:YAG laser welding
,”
Opt. Lasers Eng.
41
,
717
730
(
2004
).
14.
N.
Guo
,
Y. L.
Fu
,
X.
Xing
,
Y. K.
Liu
,
S. X.
Zhao
, and
J. C.
Feng
, “
Underwater local dry cavity laser welding of 304 stainless steel
,”
J. Mater. Process. Technol.
260
,
146
155
(
2018
).
15.
G. Y.
Chen
,
B.
Wang
,
S.
Mao
,
P. X.
Zhong
, and
J.
He
, “
Research on the ‘∞’-shaped laser scanning welding process for aluminum alloy
,”
Opt. Laser Technol.
115
,
32
41
(
2019
).
16.
X. H.
Han
,
Z. B.
Yang
,
Y.
Ma
,
C. Y.
Shi
, and
Z. B.
Xin
, “
Porosity distribution and mechanical response of laser-MIG hybrid butt welded 6082-T6 aluminum alloy joint
,”
Opt. Laser Technol.
132
,
106511
(
2020
).
17.
W.
Tao
and
S. L.
Yang
, “
Weld zone porosity elimination process in remote laser welding of AA5182-O aluminum alloy lap-joints
,”
J. Mater. Process. Technol.
286
,
116826
(
2020
).
18.
X. H.
Zhan
,
Y. Q.
Zhao
,
Z. M.
Liu
,
Q. Y.
Gao
, and
H. C.
Bu
, “
Microstructure and porosity characteristics of 5A06 aluminum alloy joints using laser-MIG hybrid welding
,”
J. Manuf. Process.
35
,
437
445
(
2018
).
19.
Y. Q.
Zhao
,
Y. F.
Wu
,
M. L.
Chen
,
Y. Z.
Gu
, and
X. H.
Zhan
, “
Research on the stripping performance during dual laser-beam bilateral synchronous welding of 2219 aluminum alloy T-joint for spacecraft
,”
J. Manuf. Process.
45
,
33
45
(
2019
).
20.
Q.
Cheng
,
N.
Guo
,
Y. L.
Fu
,
G. H.
Wang
,
M. Q.
Yu
, and
J. L.
He
, “
Investigation on in-situ laser cladding 5356 aluminum alloy coating on 5052 aluminum alloy substrate in water environment
,”
J. Mater. Res. Technol.
15
,
4343
4352
(
2021
).
21.
H.
Hosseini-Tayeb
and
S. M.
Rafiaei
, “
Enhanced microstructural and mechanical properties of Stellite/WC nanocomposite on Inconel 718 deposited through vibration-assisted laser cladding
,”
Int. J. Miner. Metall. Mater.
29
,
327
334
(
2022
).
22.
X. H.
Zhan
,
J. C.
Chen
,
J. J.
Liu
,
Y. H.
Wei
,
J. J.
Zhou
, and
Y.
Meng
, “
Microstructure and magnesium burning loss behavior of AA6061 electron beam welding joints
,”
Mater. Des.
99
,
449
458
(
2016
).
You do not currently have access to this content.