BODY ASSEMBLY PROCESSLASER WELDING VS SPOT WELDING

AUTOMOTIVE LASER WELDINGLASER WELDING COMPARISON

Process Type Laser Type Application Area Advantages Disadvantages Remarks

Single Sided Process

• CO2 - High Power (6 kW)• Nd:YAG - Low Power (4 kW)

• Butt / Edge joint (brazing applications)

• Lap joint

• TWB – Door inner panels

• Roof to side structure• Sub assembly process• Closure hemming flange

• Good weld accessibility (Single Side Process)• Reduced width of - or elimination of - the flange, resulting in reduced vehicle weight.• Low operational cost

• Panel gap constraint (no clamping force)• Narrow penetration (nugget)• Tighter parts & assembly tolerance• Worse corrosion risk vs spot welding• High price

• Jig / fixtures needed for panels clamping / support to eliminate panel gap• Suitable as MIG welding (eg CO2) alternatives

Double Sided Process

• Laser Seam Stepper (LSS) - Low Power (2 kW)

• Lap joint • Respot process • Higher process speed (shorter cycle times)• Increased component strength by longer seams with higher torsional stiffness• ‘Build in’ clamping force function (eliminate panel gap)• Low operation cost

• Weld point accessibility same as spot welding gun

• Suitable as spot welding alternatives

AUTOMOTIVE LASER WELDINGCOST COMPARISON

Estimated Cost Resistance Spot Welding

GMAW (Mix Ag/CO2) Welding

Laser Welding

RemarksSingle Sided Process

Double Sided Process

Welding Equipment per set

RM 50k to 70k RM 60k to 70k RM 450k ???•Waiting estimation from vendor

Cost per Spot

Servo / Trans Gun – 70kW

Total : RM 0.0115 Total : RM

0.016 / 10mm length

Total : RM 0.008 / 25mm

length

Total : RM 0.012 / 30mm length

*Equivalent to 3 spot welding

Pneumatic Gun – 150kW

Total : RM 0.048

Resistance Spot Welding

GMAW (Mix Ag/CO2) Welding

Laser Welding

RemarksSingle Sided Process Double Sided Process

1 spot (general) =

4√tmin (Ø) 10mm (length)18 ~ 25mm

(length)*Straight pattern

30mm / LSS*Equivalent to 3 spot

welding* Zig-zag pattern

• Reference : i. Single Sided Process : Volvo practice ii. Double Sided Process : Photonics.com

WELDING EQUIVALENT APPROXIMATION

*Note : Please refer to calculation table on “Reference” section

REFERENCESLASER WELDING VS SPOT WELDING

AUTOMOTIVE LASER WELDINGLASER SEAM STEPPER (LSS)

FIGURE 1. Laser-Seam-Stepper (left without C-Gun; right with C-Gun)

FIGURE 2. Resistance spot welding vs. laser welding with COSY LSS1-C-Gun

1 laser weld seam = 2~3 spot points

Laser welding for the production of sheet metal components in body plants offers the following advantages: 

•  Higher process speed (shorter cycle times)•  Increased component strength by longer seams with higher

torsional stiffness• Efforts and costs comparable to today’s modern resistance

welding systems• Realization of high job safety requirements with reduced costs

AUTOMOTIVE LASER WELDINGNd : YAG LASER WELDING

Figure 1:Standard Operation

Figure 2:Schematic Diagram

Laser welding advantages:

•  Narrow weld profile• Consistent weld bead• No electrode wear (Non-contact process)• High spot accessibility (1 sided process)• No filler material

AUTOMOTIVE LASER WELDINGGENERAL GUIDANCE

CO2 LaserNd : YAG

Laser

AUTOMOTIVE LASER WELDINGREFERENCE FROM VOLVO

Email

AUTOMOTIVE LASER WELDINGCOSTING CALCULATION

Day Night Average0.355 0.219 0.287

ElementsVin (V) Iin (A) Powerin (kVA) Weld Time (Cycle) Energyin (kWh)

415 170 70.55 15 0.005879167 0.001687321Powerin (kW) Moving time / Spot (sec) Energyin (kWh)

7.2 5 0.01RM / hour

78.88RM / Tip Spot / Tip

2.4 6000

0.011530654

Powerin (kVA) Weld Time (Cycle) Energyin (kWh) Cost / Spot (RM)150 15 0.0125 0.0035875

Daily Production Working Day Spot / Man Salary / Man100 20 20 1500

RM / hour78.88

RM / Tip Spot / Tip2.4 6000

Forceweld (kN) Velocityelectrode (m/sec) Powerin (kW) Squeeze Time (cycle) Hold Time (cycle) Energyin (kWh)2.45 0.2 2.23 20 5 0.000494949

0.048202884

Vin (V) Iin (A) Powerin (kVA) Weld Speed (m/sec) Weld Length (m) Weld Time (sec) Cost / length (RM)15 95 1.425 0.005 0.01 2 0.000227208

Powerin (kW) Moving time / Spot (sec) Energyin (kWh)6 5 0.011666667

Car / roll RM / Roll Length (mm/car) RM/mm RM/10mm1000 86 250 0.000344 0.00344

Car / roll RM / Cylinder RM / Car RM/10mm500 118 0.236 0.00944

0.016455542

Powerin (kW) Weld Speed (m/sec) Weld Length (m) Weld Time (sec) Cost / length (RM)4 0.083 0.025 0.301204819 0.00009605

Powerin (kW) Moving time / Spot (sec) Energyin (kWh)6 5 0.008835341

0.008931392Powerin (kW) Weld Time (sec) Cost / length (RM)

2 2 0.00031889Powerin (kW) Moving time / Spot (sec) Energyin (kWh)

6 5 0.011666667

0.011985556Total

Lase

r Wel

ding

- 0.0116666677.5

- - - - - -

Doub

le S

ided

Pro

cess Weld Setting - -

Robot Power Apparent Power (kVA)

- 0

Total

- -

Sing

le Si

ded

Proc

ess

- - - - -

Weld Setting

Robot Power Apparent Power (kVA) - 0.0088353417.5

GMAW

( M

ix Ag

/ CO

2)

- -

Total

0.003348333

0.00344

0.00944

0

CO2 Gas - -

- - - -

CO2 Wire -

Weld Setting

Robot Power Apparent Power (kVA) -7.5

-

Total

Resis

tanc

e Sp

ot W

eldi

ngElectrical Tariff, RM / kWh

Parameters

- - -

- - -

-

-

-

-

Total

- -

-

- -

-

-

-

-

0.0004

Pneumatic / Air0.000142051

- - - -

- - -

Serv

o /

Tran

s Gun

Pneu

mati

c Gu

n

Welding Transformer

Manpower 0.0375

Water Pump 0.006573333

Electrode Tip

Water Pump 0.006573333

Electrode Tip 0.0004

0- - - -

Welding Transformer

Robot Power Apparent Power (kVA)9

0.00287

Cost / Spot (RM)