welding outline 2012c rev 1

7/28/2019 Welding Outline 2012C Rev 1

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Fiber LASER Welding processing outline

AMADA LASER

V2012C


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Table of contents

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2

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5

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9

10

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14

15

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Appendix 1

Appendix 2

Table of contents

Fiber Laser Welding feature

Focal point (1)

Relation between laser focal point and welding

Process of key-hole shaped laser welding

Process of heat-transfer laser welding

Focal point (2)

Focal point (3)

CW (Continuous Waves) and pulse

Laser conditions number

Gas shield

Gap joint

Filler material

Initial setting for filler processing

Operation of filler setting

Processing condition of Fiber Laser Welding machine

Example of the application of condition by work

Example of the application of condition by work 2

Quality control guideline

Quality control guideline 2


Processing failure

Processing failure 2

Welding of different thickness parts

Spot welding with laser

Tack welding method

Create a new processing condition

Fiber Laser

Condition E number list


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Pulse area Pulse area

Fiber Laser Welding enables you to operate selecting the characteristic processing described below.

2

Fiber Laser Welding feature Fiber Laser that enables wide range processing

High speed

thin-sheet welding

Precise welding

Laser

power

Versatile

Low-distortion

welding

Finishing-less

welding with

smooth surface

Middle-thick sheet

weldingAluminum

welding

Laser spot

diameterSmallest Medium Large

Spatter area


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Focal point (1)Focal point (1) The element of focal point is an important way of thinking about laser processing.

Condensed lens

Spatter-protective

glass

In laser, there is a range that keeps approximately constant laser-spot-diameter. As

the range is wider, the processing is more stable. (so-called focal depth)

High power-density

Key-hole welding

Aluminum

processing

range

Low power-density

Heat-transfer welding

The focal depth depends on the quality of laser beam, the fiber diameter and focus lens.

3

Low power-density

Heat-transfer welding

DEFOCUS stands for making a distance of the position

(heights) between lens and material.

And it can change the diameter of laser spot welding.

Focal point

Practical laser focal point

Beam at focal point (example)

Beam diameter is about 450um in FLW.

Defocus beam (example)


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Find the differences by bead with bead-on-plateRelation between laser focal point and welding

Laser lightLaser light

Key-hole type Heat-transfer type

Equivalent to DF [0] Equivalent to DF10-50

Laser-spot-diameter changes the processing condition significantly


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Welding section

Laser irradiation (pulse drive msec)

0 -2 msec 2- 10- About 5 msec after irradiation

This chart shows the progress of laser welding (pulse example).

1 cycle is approximately 2/100 seconds so that it cannot be confirmed in the normal condition.

When laser irradiation

is stopped,

immediately the

keyhole is closed and

coagulated from the

boundary by the

cooled base material.

Laser

The light makes the

electrons on material

surface oscillate and

produce heat.

Electrons

Metal atoms that quickly

evaporate create a

repulsive force on the

weld metal side.

Evaporation reactive

force

The keyhole is accompanied

with wall-focusing effect

with special phenomenon of

electron beam welding and

laser welding

What happens in the material during

laser welding

In the initial step,

the material surfacestarts evaporation.

It takes 2 msec to get

sufficient heat.

Evaporation reactive

force pushes out the weld

part.

Repeating the laser light

irradiation and reflection

into the created

depression, the

depression becomes

deeper, then a keyhole is

created.

Laser reflect back

from the wall

When the forming of

keyhole is almost

finished, heat in the

weld part reaches the

material and the

penetration continues

to spread gradually.

As the pulse height is

higher, the keyhole

becomes larger and

deeper.

5

Process of key-hole welding


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Laser-lights power density changes the process of laser processing.

What happens in the material during

laser welding

6

Process of heat-transfer laser welding

At the end of welding, wave-shaped metal

is joined by the surface tension.

When gap and high feed rate are over

the tension, un-joined parts may occur.


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The diameter of laser focal point is an important parameter for processing.

It shows the relation between focal point diameter and processing.

When the focal point moves close to the lens, the reflected light comes back to the optical fiber.

= Minus focus is not allowed to use.

Focal point(2)

Key-hole

weldingProcessing statusHeat-transfer

welding

Heat-transfer

welding

Impossible

to process

Impossible to

process

Welding part

The position of focal point

Df=0.45mm

Deep penetration

Large-stroke weavingLow penetration

Smooth

Low penetration

Smooth

High speed

Many smokesOther features

High reflection

Weak in gapHigh reflection

Weak in gap

Beam direction


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This page shows the relation between processing application purpose and focal point position.

Some material types may not make the spot diameter longer.

When the focal point moves close to the lens, the reflected light comes back to the light fiber.

= Minus focus is not allowed to use.

Focal point (3)

Focal-point

position

Df=0.45mmBeam direction

DangerDangerDangerA1050, A1100, Brass

DangerDangerA5052

SEC

SPC

Danger

FP+40

Danger

FP+30FP+10

Danger

FP+20

DangerHigh-reflection materialsuch as Cu, Ag, Au, Pt

SUS

FP+50FP 0Material type


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CW (Continuous Wave) and pulseCW (Continuous Wave) and pulse

In pulse, the light is created for one shot

intermittently, and intricately like the leftpicture with the circles overlapping in a row.

(in case of the duty of 60% or less.)

9

1 pulse

Weld pooldiameterOverlap

Pulse laser welding system

CW laser welding system

In CW, the light moves continuously while

welding material, so that it realizes high

speed processing with high heat amount.

(Small weaving stroke stands for the cooling

and solidifying line.)


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In laser, the maximum average power shows the performance of laser oscillator.

Additionally , in pulse irradiation, duty ratio and single-pulse energy are important.

During pulse oscillates,,, time

Average power W (watt)Average power W (watt)

timeAverage value

Look at the moment of pulse time

Set power W (watt)Set power W (watt)

timeInstantaneous power value

Look at only one pulse time

Reference : Pulse energy J (joule)Reference : Pulse energy J (joule)

Shows one-pulse energy (heat amount)

10

W

dimensions

Laser conditions number

time

Frequency Hz (hertz)Frequency Hz (hertz)

time

Number of pulse outputs in one second.

time

Duty % (percent)Duty % (percent)

timeON/OFF ratio (%) in one cycle

ON

set power x duty

OFF ON Duty 70%


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At approximately 400 degree Celsius, mild steel materials start oxidizing at the surface.

Using a shield gas, it is possible to protect the bead from oxidizing.

11

Gas shield

Shield Colour MapStainless Steel 304

1.E+03 1.E+04 1.E+05

Oxygen Dencity (ppm vol.)

ShieldComplete

ShieldEnable

(bead-sideyellow)

Yellow

(Gold)

BrownishYellow

(DarkGold)

Violet

MetallicBlue

GrayishBlue

Gray

Oxygen density must be 5000 ppm or less.

(Ar purity 99.5 or more)

Traveling direction

Tilt the side nozzle to the traveling direction to

make the nozzle gap small.

Gas flows to the direction of processing point

so that the shield effect improves.

Oxygen density and bead coloring (burn) data example


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12

Joint of the gap between materials, how to deal withGap joint

Beam weavingBeam weaving

Un-joined in the gap between materials

The reason why the gap between materials are

un-joined is mainly the laser light does not reach

the materials.

Weld the edge surfaces of materials and join the gap with filling.

Margin

s-10%t

By welding the edge of gap with sufficient heat, the fluid level oscillates

and sinks in and and surface tension occurs.

And then the gap is filled.

Margin

s-30%

t

Stir the focal point


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For overlaying, the filler wire that is appropriate to materials must be mounted to machine.The following chart is the generally applied wires.

Processing design for laser build up welding

13

Filler material

A5183-WY

A5356-WY0.81.6A5183A5356A5052

Z 3312YGW12

0.91.6Solid wire for MS CO2 weldingSPHC

Z 33210.81.6Y308 for stainless MIGSUS304

A5356-WY0.81.6A5356A6000 series

1.01.6

0.81.6

Wire diameter

A1100A1100

Z 3316

or Z 3312

YGW12

Solid wire for MS TIGMIG

or solid wire for CO2 welding

SPCC

SECC

JISApplied wirecommonly known asWelding

material

Depends on the specification of feeding device, such as the spool diameter and filler diameter. Confirm the machine.

Wire diameter must be selected and changed depending on the thickness to process (volume to fill) .

See the filler diameter of processing condition chart.

Good

Processing on

corner part

Toomu

ch

overlay

ing


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For overlaying, the position of filler wire feeding nozzle is important.

Practical operation for laser build up welding

14

Initial setting for filler processing

LCD shows the status seen from top.

Head moves

Set a little behind

the target.Set the head in an

appropriate height and fix

the position where the

wire touches the material.

To see the filler

wire tip

LCDscre

en

For wire welding, make the laser spot

bigger, or use weaving together.

Nozzle

The processing condition must be set E10 with beam weaving

for placing importance on stability.


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Processing condition is decided by the parameters of material type, thickness and E number.

Processing condition of fiber laser welding

machine

Such as open and fillet, material thickness/leg length

settingDF[1]Weaving filler E10

Spare 3Reserve3E11

E27

Do not use/change for wire dedicated purpose or fixed

macro such as overrideProhibited to use Customization forspecial purpose)

E28

E30

PurposeDEFOCUSNameNo.

DF[1]

DF[1]

DF[2]

DF[1]

DF[0]

DF[2]

DF[1]

Weaving

Spare 2

Spare 1

Filler standard

Flat

Standard

High speed

Hard pulse

Standard pulse

For gap gap= sheet thickness 30%

For flat finishing, standard gap t X30%

R finishing, flat finishing

General purpose stable condition for standard gap

High speed welding, lap welding application

Gap processing, corner processing

Overheated part, edge condition and minimum

deformation under the standard setting

E9

E6

E5

E4

E7

E3

E8

E2

E1

For using filler wire, with weaving is recommended. Get advice for the special conditions such as , .

Amada fiber laser system performs processing

based on the standard condition chart


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According to the quality required for each product, condition files are selected.

Practical operation of

processing condition

17

Example of the application of

condition by work

Welding with deep penetration

Welding on a smooth surface

Overlaying with fillet for weld strength

Thin sheet welding with minimum distortion Use E1 with appropriate material type and thickness

Use E4 with appropriate material type and thickness



Lap welding Select a thicker sheet and use E3

NameNo.

WV-F

WV

Spare 2

Spare 1

Filler STD

Flat

Standard

High speed

Hard pulse

STD pulse

E9

E6

E5

E4

E7

E3

E10

E8

E2

E1

Goes through

lapped sheets


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According to the shape/quality of each part,

select and apply a condition file.

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Example of the application of

condition by work 2

Product to be welded tightly with fine bead

composed of fillet welding (overlaying)

aWelds down the edge ofmaterial in a wide-width bead

b. Large crater on the end edge part

Product to be welded smoothly

composed of some complicated shapes

With appropriate material type/thickness, switch

E5E2

With appropriate material type/thickness, switch

E4E10

With appropriate material type/thickness

E5 set SLOPEDOWN

Note that the switch is the same focal point condition (blueblue, redred)!

NameNo.

WV-F

WV

Spare 2

Spare 1

Filler STD

Flat

Standard

High speed

Hard pulse

STD pulse

E9

E6

E5

E4

E7

E3

E10

E8

E2

E1

On a corner or small part, use pulse with low speed not to cause too much weld.

When changing the conditions that switch gas condition, focal point position

and weaving or not, the processing is paused once and restarted.

In this case, the processing is paused at the switch part.

In a product with various joint types, you need to change the condition in order to process.


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Welding feasibilityWelding feasibility

Intensity (penetration)Intensity (penetration)

Outer appearance (burn/bead)Outer appearance (burn/bead)

Distortion and accuracy mattersDistortion and accuracy matters

Crack and pinCrack and pin--holeholeCorrosiveness and durabilityCorrosiveness and durability

Other qualities in the environment for using.Other qualities in the environment for using.

19

In welding process, depending on the products function and feature, the quality is common to be required strictly.

The followings are the qualities required particularly.

To fulfill the required quality, the

control elements to improve are

Material controlMaterial control

Previous process controlPrevious process control

Welding machine controlWelding machine control

Welding process controlWelding process controlAfterAfter--welding process controlwelding process control

Here are the examples of quality control in laser welding process taking from the past cases of laser welding machine control and welding process control.

Material control

Normally, materials examination is done when prototyping, sometimes the welding situation changes due to the oxide coating with rust, impurities,

various errors in processing.

A good first step is to be careful about the material features and to decide approximate material control.

Oxide

coating on

welding

surface,

sticky tape,

etc.

Rust, grease,

etc.

Quality control guideline

SK materials, aluminum alloy, etc. are the

materials that are originally easy to crackdue to the depressions and conditions.

Furthermore, aluminum oxide coating

makes the welding status worse.

SUS316 and SUS430 are the materials that

crack and become weak by the lack of

penetration.

Titanium and nickel occasion welding

failure depending on the gas selection.


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The most dependable and simple way is to have regular processing with regular materials and check if it is a regular result or

not? (go to the next page)

20

Machine control


The quality elements of laser welding machine are the three of laser light, gas and traceability.

Especially the control of laser light is important, so here is an example as a guideline of processing machine control.

Oscillation part Beam SW Light fiber

Collimated lens Focus lens Protective glass Material

Route of laser light

A laser light irradiates a material going through the several devices as the above chart.

The protective glass and focus lens are able to be visually checked by eye before operation.However, in the case that can not be checked by eyes and the failures in other parts are not able to be found.

Oscillator panel shows

the status of this part in

the power monitordisplay (W).


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Quality control guideline 3 An example of quality control is below. Select your way of quality control referring them.

Surface plate

Prepare and fix an area to put certain

materials, somewhere on the plate where

is not used so much or a material-

dedicated table at the side.

SUS304 t2.0 is recommended as the

material.

SUS304 t 2.0

Creates a program only to put a

bead on the material surface. Programming exampleJOB nameWELCHECK

M102L P[1]R[1]Cm/min CN100

L P[2]R[1]Cm/min CN100E No(4)

LASERON

L P[3]R[1]Cm/min CN100

LASEROFF

L P[4]R[1]Cm/min CN100

END

Front

Back

yyyy mm dd Ichiro

Records the date, PIC, etc.

and compare to the

master.

For the back surface

status, select the

optimum condition (that

can see easily).

According to the work status, execute WELCHECK regularly, check

the back surface and start the processing.

?

When the bead status

changes, the

modification in the

override and condition

setting are necessary.

Sometimes the others

and machine

maintenance are also

needed.

Be sure the certain position, height and condition to process.

Do not change the teaching also, without special reason.

SUS2.0 E4


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Crack occursCrack occursImprovement example: Keep the material temperature high. (decrease the processing speed, increase the duty, etc.) Improvement example: Make the shape of bead surface convex. (R shape of angle joint, filler wire, etc.) Improvement example: Avoid the stress from concentrating. ( release from constraint, divide the line, fine tack welding, etc.)

The crack improvement causes burns with increasing heat input, the distortion may increase.Moreover, sometimes the crack is not improved because of the material feature.

Crater crack

Lateral bead crack

Vertical bead crack

Names of majur welding crack failures

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Processing failure

Embitterment of welding metalEmbitterment of welding metal

If there is no crack, brittle metals are created and the strength to resist shock decrease.

As it depends on the feature of solidified metal body, this problem may be difficult to clear.

The typical materials are the one with heat processing (hardening, annealing), high carbon steel and tool steel.

Improvement example: Increase duty and change CW.

Improvement example: Use the appropriate filler wire.


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Blowhole occursBlowhole occurs

Improvement example: Eliminate the failure elements on the joint surface.(When getting oxide coating/thin coating, occurs a blowhole.

Improvement example: Have the bead condition to penetrate.(Key hole bead that does not penetrate occurs blowhole.

Improvement example: Increase the shield effect and use nitrogen for gas.(When bead oxidizes, occurs blowhole. Using nitrogen, the hole becomes small.)

Improvement example: Tilt the head, use the high frequency wave (50-300Hz) pulse.(In specific materials, sometimes brings effect.)

In this case, burn occurs because of increasing heat input. And sometime the hole may not disappear for the material feature.

Blowhole

23

Processing failure 2

Distortion/burn occurDistortion/burn occur

When the input power is stronger than the fixed welding length, it appears noticeably.The burn can be improved by shield gas, but it is difficult to make the distortion zero.

Improvement example: Make the focal point small and processing speed high.Improvement example: Use pulse.Improvement example: For long length welding, divide it and weld in order from the center of work to outside.


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The welding of the sheets with different thickness, the welding way is different depending on the joint, however, the laser

with small heat transfer is comparatively easier than Tig.

In laser welding, the sheet thickness to weld is not a problem. Select the condition according to the penetration depth.

t1

t2

From an oblique direction,

irradiate the light.

t1

t2

Weld in the

condition of 2t.

t1 t2

Weld in the

condition of 1t.

t1

t1Weld in the

condition of 2t.

t1

t2

Weld in the

condition of 2t.

t1

t3

Weld in the condition of 2t.

t1

t3

In case of 3t-condition welding t6

In the 3mm-condition of penetration

depth, it is possible to weld all 6mm from

the both sides.

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Different thickness welding

Reference

Lap welding case


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Laser spot weldingIn laser spot welding, it is possible to weld stopping for each time, and also moving.

By making the frequency wave and duty low, the interval of laser beam irradiations becomes long. As a

result, it looks like spot welding.

Feed rate 120cm/min 1200mm/min

FW Hz(2 times irradiation/sec)

In the above condition,

12006020mm/sec

20mm210mm

It becomes 10mm-pitch spot welding.

When making the feed rate 2 times of 240cm/min = 2400mm/min, the pitch becomes 2 times as 20mm.

Moreover, when making the FW 4Hz with the same rate, the pitch becomes half as 5mm.

Reference

Spot welding with laser

25


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Reference

Without tack welding, the situation in the above chart happens.

With tack welding, the line does not open so that it brings good welding.

Tack welding is very important in laser welding also.

Tack welding

Tack welding method

26


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Create a teaching program of bead-on-plate, and take a look at the bead status changing the number of Processing speed/Laserpower W/Frequency wave Hz.

(Notes) When handling new materials and prototyping, the conditions for users are convenient to use.

Set the mode key edit, select the material thickness from list and press down detail key.

Take note of the standard condition (current value) of material to use.

Touch the control panel and change the condition number to use.

Create the teaching program of bead-on-plate using the above condition number. !Beware of the reflection light !

Process with the set condition and confirm the bead. easy to see the difference comparing to the standard condition.)

Proceed referring to the below chart (an example).

Speed Power FW Duty Main gas Side gas STD condition Increse power W Decrease power W Increase duty % Decrease duty % Increase FW Hz

Decrease FW Hz

Change power and

speed with same %

Material type: Material thickness: Condition number:

(Notes) The minimum number (guarantee) of power is 10% of rated power.

For the gas value, 50L/min is the maximum flow amount to set.

When changing the frequency waves even duty is flat, one pulse energy changes.

Create a new processing condition

27

Reference


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Appendix 1

Appendix 1 Fiber Laser

Doped coreDoped coreDoped coreDoped core

Reference


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Appendix 2

Appendix 2 Condition E number list

PurposeSymbolNameNo.

Weaving filler

Weaving

Spare 2

Spare 1

Filler standard

Flat

Standard speed

High speed

Hard pulse

Standard pulse

Sheet thickness and leg length setting such as open,

fillet

For gap gap=sheet thickness t x 30%)

Reserve 2

Reserve 1

For flat finishing, standard gap t x 20%

R finishing, flat finishing

General-purpose stable condition in the standard

gap

High speed welding, lap welding application

Gap processing, corner processing.

Overheated part, edge condition, minimum

distortion in the standard setting.

E9

E6

E5

E4

E7

E3

E10

E8

E2

E1

Utilize this chart, putting a copy on the wall.

welding outline 2012c rev 1

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