1 Friction Stir Welding
17
Table 1.3 FSW of magnesium alloys at different plate thickness, tool material, spindle speed and
welding speed
workpiece
material
Thickness
(mm)
Tool material Spindle speed
(rpm)
Welding speed
(mm/min)
Reference
AM60
20
Tool steel
2000
120
[13]
AZ31
4
65Mn steel
375–2250
20–375
[69]
AZ31
6.3
–
800–3500
100
[70]
AZ31B
4
Tool steel
1250
250–750
[33]
AZ31B
3.2
H13
1200–1750
305–762
[10]
AZ31B-H24
4
D2 (SKD11)
1250–2500
87–342
[30]
AZ31B-H24
3.2
–
1500, 2000
78–204
[46]
AZ61A
6
High-carbon
steel
1200
90
[53]
ZK60
3, 6
–
600–2000
100–400
[36]
AMX60
4
SKD61 tool
steel
1100
200–400
[6]
1.5.4 Steel
Nowadays, the FSW technique is being focused on joining various types of steel
as it being the most important engineering material. Steel constitutes the major
components in various structures, buildings, machines, etc. FSW studies have been
conducted on mild steel (AISI 1010), low-carbon steel, austenitic stainless steel
(316L, 304L), super-austenitic stainless steel, high-strength low-alloy (HSLA-65)
steel, super duplex stainless steel (SAF 2507), duplex stainless steel (DH-36), creep
resistance steel (P91, P92). The process parameters and the tool materials depend
on the particular variety of steel as well as the plate thickness. For FSW of steel,
shielding by an argon gas environment is provided to protect both the weld zone
and tool from oxidation. As already mentioned, FSW produces much lower heat
compared to fusion welding. Thus, the chances of metallurgical changes in the HAZ
of the material are lesser in case of the former. Moreover, chances of distortion and
residual stresses in steel are also lesser in case of FSW which makes it suitable
for welding of thicker plates as demanded in shipbuilding and heavy manufacturing
industries. The issue of hydrogen cracking in steels is also non-existent in case of
FSW as it is a solid-state joining process. FSW of different types of steel at different
plate thickness, tool material, spindle speed and welding speed is given in Table 1.4.
1.5.5 Titanium Alloys
It is possible to weld a variety of titanium-based alloys to be welded by conventional fusion-based technique, viz. gas tungsten arc welding (GTAW). However,
17
Table 1.3 FSW of magnesium alloys at different plate thickness, tool material, spindle speed and
welding speed
workpiece
material
Thickness
(mm)
Tool material Spindle speed
(rpm)
Welding speed
(mm/min)
Reference
AM60
20
Tool steel
2000
120
[13]
AZ31
4
65Mn steel
375–2250
20–375
[69]
AZ31
6.3
–
800–3500
100
[70]
AZ31B
4
Tool steel
1250
250–750
[33]
AZ31B
3.2
H13
1200–1750
305–762
[10]
AZ31B-H24
4
D2 (SKD11)
1250–2500
87–342
[30]
AZ31B-H24
3.2
–
1500, 2000
78–204
[46]
AZ61A
6
High-carbon
steel
1200
90
[53]
ZK60
3, 6
–
600–2000
100–400
[36]
AMX60
4
SKD61 tool
steel
1100
200–400
[6]
1.5.4 Steel
Nowadays, the FSW technique is being focused on joining various types of steel
as it being the most important engineering material. Steel constitutes the major
components in various structures, buildings, machines, etc. FSW studies have been
conducted on mild steel (AISI 1010), low-carbon steel, austenitic stainless steel
(316L, 304L), super-austenitic stainless steel, high-strength low-alloy (HSLA-65)
steel, super duplex stainless steel (SAF 2507), duplex stainless steel (DH-36), creep
resistance steel (P91, P92). The process parameters and the tool materials depend
on the particular variety of steel as well as the plate thickness. For FSW of steel,
shielding by an argon gas environment is provided to protect both the weld zone
and tool from oxidation. As already mentioned, FSW produces much lower heat
compared to fusion welding. Thus, the chances of metallurgical changes in the HAZ
of the material are lesser in case of the former. Moreover, chances of distortion and
residual stresses in steel are also lesser in case of FSW which makes it suitable
for welding of thicker plates as demanded in shipbuilding and heavy manufacturing
industries. The issue of hydrogen cracking in steels is also non-existent in case of
FSW as it is a solid-state joining process. FSW of different types of steel at different
plate thickness, tool material, spindle speed and welding speed is given in Table 1.4.
1.5.5 Titanium Alloys
It is possible to weld a variety of titanium-based alloys to be welded by conventional fusion-based technique, viz. gas tungsten arc welding (GTAW). However,