ARW Presentation

8/7/2019 ARW Presentation

1/41

w w w . a s p . o r g

www.a-sp.org

Development of Starting WeldSchedules for AHSS

SORPAS Modeling of Starting Point Weld Schedules with

Experimental Evaluation and Validation

Michael L. Kuntz University of WaterlooDonald F. Maatz Jr. RoMan Engineering Services

Eric Pakalnins - Chrysler

John C. Bohr General MotorsTed Coon & Armando Joaquin - FordAuto/SteelPartnership


2/41


Background

Starting Point Weld Schedules Used by automotive manufacturers for first welds as

a basis for weld schedule development Schedules depend on the governing metal thickness

(GMT) and material coating

Schedules currently in use for mild steel and HSLA(IISI Groups 1 and 2) need to be adjusted for AHSS(Groups 3 and 4) to produce acceptable weld quality

Developing starting point weld schedules is potentiallytedious and material intensive due to the wide range of material combinations.


3/41


Objectives

Phase I Verify starting point weld schedules for IISI Groups 3

and 4 AHSS using the SORPAS finite elementsoftware, and

Suggest schedule improvement if necessary because of undersized welds or other observed defects.

Phase II Verify RSW Weld Schedule Effectiveness by:

Peel Inspection Mechanical Evaluation Metallographic Analysis


4/41w w w . a s p . o r g

Scope of Work

Weld schedules developed with A/S-P member input AC & MFDC OEM production Cu-Zr electrode tips

AC: AWS D8.6 ball nose , 4.8 mm contact face diameter MFDC: ISO 5821 B nose, 6/8 mm contact face diameter

Thickness combinations: Test A: 2T stack-up, similar thickness Test B: 2T stack-up, thickness ratio 1:2.5

Test C: 3T stack-up, mild and BH steels to group 3 and 4

AC electrode MFDC electrode


5/41w w w . a s p . o r g

3T Stack-Up Thickness Combinations

3T Simulations with thin Mild Steel (140YS/270TS)

Uncoated Gages(mm) Coated Gages(mm)

#1 #2 #3 #4 #5 #6

Thin (mild) 1.08 0.92 0.76 0.64 0.76 0.64

Thick 2.70 2.30 1.90 1.60 1.90 1.60

Thick 2.70 2.30 1.90 1.60 1.90 1.60

Stack-upDescription

1.601.901.601.902.302.70Thick

1.601.901.601.902.302.70Thick

0.640.760.640.760.921.08Thin (mild)#6#5#4#3#2#1

Coated Gages(mm)

Uncoated Gages(mm)Stack-upDescription

3T Simulations with thin BH Steel


6/41w w w . a s p . o r g

Phase I - Simulation

Steels that were selected for simulation: Bare and Zn-coated IISI Groups 3 and 4

TRIP 800 MPa DP 600 MPa DP 980 MPa

Uncoated Hot Stamped Boron Bare and Zn-coated IISI Groups 1 and 2

Mild 140 YS/270TS BH 210 MPa


7/41w w w . a s p . o r g

Simulation Parameters

SORPAS v.7 FEA software Squeeze time - 5 cycles

Current specified by RMS with a constant currentcontrol power supply 60 Hz AC with a conduction angle of 60%

Axissymetric 2.5d model with 500 elements SORPAS interface condition parameter - 1.0

10C water cooling HDGI coating weight of 75 g/m 2 per side for coated

materials


8/41w w w . a s p . o r g

AC Welding Simulation Results Summaries


9/41w w w . a s p . o r g

AC - Uncoated Steel Schedules

AC Weld Schedules (For Squeeze Time Use 5 cycles)

Uncoated IISI Group 3 (High Strength >500-800 MPa) and Group 4 (Ultra High Strength >800 MPa)

Test GMTRange (mm)

WeldForce(lbs)

WeldTime

(cycles)

CoolTime

(cycles)

Numberof

Pulses

WeldSequence(Cycles)

HoldTime

(Cycles)

WeldCurrent

(kA)

ElectrodeShank Diameter

(mm)

A, B 0.70 - 0.79 480 9 0 1 9 2 8.0 15.9

A, B 0.80 - 0.99 670 9 0 1 9 2 8.0 15.9

A, B 1.00 - 1.29 670 10 0 1 10 2 9.0 15.9A 1.30 - 1.59 950 12 0 1 12 2 10.0 15.9

A,C 1.60 - 1.89 1200 7 1 2 7-1-7 5 10.5 19.0

A,C 1.90 - 2.29 1660 7 1 3 7-1-7-1-7 5 11.5 19.0

A,C 2.30 - 2.69 1660 8 2 3 8-2-8-2-8 10 12.0 19.0

A,C 2.70 - 3.00 1900 8 2 3 8-2-8-2-8 10 12.5 19.0


10/41w w w . a s p . o r g

AC - Coated Steel Schedules

AC Weld Schedules (For Squeeze Time Use 5 cycles)

Coated IISI Group 3 (High Strength >500-800 MPa) and Group 4 (Ultra High Strength >800 MPa)

Test GMTRange(mm)

WeldForce(lbs)

WeldTime

(cycles)

CoolTime

(cycles)

Numberof

Pulses

WeldSequence(Cycles)

HoldTime

(Cycles)

WeldCurrent

(kA)

ElectrodeShank Diameter

(mm)

A, B 0.70 - 0.79 480 14 0 1 14 2 9.0 15.9

A, B 0.80 - 0.99 670 14 0 1 14 2 9.5 15.9A 1.00 - 1.29 670 16 0 1 16 2 10.0 15.9

A 1.30 - 1.59 950 7 1 3 7-1-7-1-7 5 11.0 15.9

A,C 1.60 - 1.89 1200 8 2 3 8-2-8-2-8 5 11.5 19.0

A,C 1.90 - 2.29 1660 8 2 4 8-2-8-2-8-2-8 5 12.5 19.0


11/41w w w . a s p . o r g

Test A DP980 Results


12/41w w w . a s p . o r g

Test B TRIP800 Results


13/41


14/41


Test C DP980-Mild Steel Results


15/41


Test C DP980-BH Results


16/41


DC Welding Simulation Results Summaries

DC U d S l S h d l


17/41


DC - Uncoated Steel Schedules

Uncoated IISI Group 3 (High Strength >500-800 MPa) and Group 4 (Ultra High Strength >800 MPa)

Test GMT Range(mm)Weld Force

(N)Weld Time

(ms)Weld Current

(kA)Hold Time

(ms)

Electrode

FaceDiameter

(d 2)

ElectrodeWidth

(d 1)

A, B 0.70 - 0.79 2800 210 6.5 105 6 16

A, B 0.80 - 0.99 3400 210 7.6 105 6 16

A, B 1.00 - 1.294400 270 9.3 135 6 16

A 1.30 - 1.59 5300 350 10.6 175 8 20

A,C 1.60 - 1.89 6400 440 11.2 220 8 20

A,C 1.90 - 2.29 7700 560 12.0 280 8 20

A,C 2.30 - 2.69 8500 670 12.5 335 8 20

A,C 2.70 - 3.00 10200 880 13.6 440 8 20

DC C t d St l S h d l


18/41


DC - Coated Steel Schedules

Coated IISI Group 3 (High Strength >500-800 MPa) and Group 4 (Ultra High Strength >800 MPa)

Test GMT Range(mm)Weld Force

(N)Weld Time

(ms)Weld Current

(kA) Hold Time

ElectrodeFace

Diameter(d 2)

ElectrodeWidth

(d 1)

A, B 0.70 - 0.79 2800 230 7.8 115 6 16

A, B 0.80 - 0.99 3400 250 8.5 125 6 16A 1.00 - 1.29 4400 310 10.1 155 6 16

A 1.30 - 1.59 5300 400 11.5 200 8 20

A,C 1.60 - 1.89 6400 480 12.4 240 8 20

A,C 1.90 - 2.29 7700 600 13.2 300 8 20

Test A DP600 Res lts


19/41


Test A DP600 Results

Test A TRIP800 Results


20/41


Test A TRIP800 Results

Test B DP600 Results


21/41


Test B DP600 Results

Test C DP600 Mild Steel Results


22/41





23/41



Test C DP980-BH Results


24/41


Test C DP980 BH Results

Phase I - Conclusions


25/41


Phase I Conclusions

Starting point RSW schedules were checked using thecommercially available SORPAS v.7 software

Weld schedules for both AC and DC RSW of both coated and

bare AHSS were evaluated and found to give acceptable results The given starting point weld schedules can be used to ensureacceptable weld size during the development of production RSWschedules

The schedules are intentionally hot as they are designed toproduce large welds over a wide range of conditions

Expulsion can be expected with these schedules and the

necessary safety precautions should be exercised These RSW schedules are not optimized for production

conditions

Phase II - Validation


26/41


Phase II Validation

Evaluate the starting point weld schedules for variouscombinations of steel grades and gauges

590R 1.20, 1.40, 1.54 DP600 1.20, 1.60, 1.97, 2.20 DP750 1.50 (planned for DP780, substituted) DP780 1.15, 1.60

TRIP800 1.00, 1.50 DP980 1.40, 1.60, 1.92

Weld sample coupons based on AWS D8.9M:2002

Size and weld placement determined by material gauge All 3T assemblies produced with 2 x 6 coupons

Assembly and Inspection Procedure


27/41


y p

Peel samples (weld 5 samples, evaluate 3) Visual inspection per AWS D8.1M:2007, Section 5.1 Peel inspection per AWS D8.1M:2007, Section 5.3

Tensile-shear and cross-tension samples (weld 5 samples,evaluate 3)

Weld property determination per AWS D8.9M:2002, Section 11.6 Static peak load

Evaluate results per AWS D8.1M:2007, Section 5.4

Metallographic (weld 2 samples, evaluate 1) Sample preparation per AWS D8.9M:2002, Section 11.5

Micro-hardness and un-etched photo not required Evaluate results per AWS D8.1M:2007, Section 5.2

Peel Test Requirements


28/41


ee est equ e e ts

Test inspection requirements - Peel Samples Visual inspection per AWS D8.1M:2007, Section 5.1

Surface imperfection inspection without magnification Indentation measurement with depth gauge

Peel inspection per AWS D8.1M:2007, Section 5.3 Weld size requirements based on GMT and requirements of

Table-2 Fracture mode

Tensile Test Requirements


29/41


q

Test inspection requirements mechanicals (TS & CT) Weld property determination per AWS D8.9M:2002, Section 11.6

Static pull @ 10 mm/min Evaluate results per AWS D8.1M:2007, Section 5.4

Weld size Fracture mode

Peak load weld strength (per Equations Below)

Metallographic Test Requirements


30/41


g p q

Test inspection requirements - metallographic Sample preparation per AWS D8.9M:2002, Section 11.5

Micro-hardness and un-etched photo not required Etched photomicrograph at 10X

Evaluate results per AWS D8.1M:2007, Section 5.2 Fused nugget diameter

Depth of penetration Welding discontinuities

Porosity Voids Cracks

Internal Surface

Results Indentation AC


31/41


1.201.401.541.201.601.971.15

1.501.601.001.501.401.601.92

1.2/2.2

1.15/1.6

1.0/1.5

1.4/1.92

1.0/2.2

1.0/1.92

0.45 0.42 0.360.49 0.47 0.44

1.11

0.41

0.59

0.590.50

0.52 0.52

0.66 0.660.55 0.55

0.480.59

1.05

0.64 0.61 0.450.29 0.42

0.39 0.38

0.48 0.49 0.500.77 0.83 0.68

0.52

0.360.420.460.36

Weld IndentationMaterial A

(Top)Material B

(Middle)Material C(Bottom)

Test2 - Top 2 - Bottom 4 - Bottom

30%Limit

Peel Sample Weld Indentation (mm)

DP750DP780 (B) 0.41 0.420.470.53TRIP800TRIP800

DP980

0.45

0.470.630.37

590R590R (B)

590RDP600DP600DP600DP780

DP600DP980 (B)

DP600DP980 (B)

DP600DP780 (B)TRIP800

DP980 (B)

DP980 (B)DP980 (B)

0.480.41 0.37

0.32 0.370.66

0.41 0.40

----

590R590R (B)

590R

---

DP600DP600DP780

DP750

--

-

0.53 0.50

0.48 0.42

0.32

0.36 / 0.660.35 / 0.480.30 / 0.45

0.450.420.480.58

0.420.52

0.410.49

0.570.60 0.49 0.37

0.420.64 0.64 0.63

0.470.60

0.67 0.731.06 0.79 0.781.26

-

----

---

DP780TRIP800

DP980

MildMild

DP600

DP780 (B)TRIP800TRIP800

DP980DP980 (B)DP980 (B)

4165r20a

4165r16a

4165r17a

4165r18a

4165r19a

4165r12a

4165r13a

4165r14a

4165r15a

4165r8a

4165r9a

4165r10a

4165r11a

4165r1a

4165r2a

GMT

0.45

4165r3a

4165r4a

4165r5a

4165r6a

4165r7a

DP600

4 - Top0.410.500.530.370.440.69

0.35

0.450.480.30

0.42 / 0.58

0.30 / 0.660.30 / 0.58

Results Indentation DC


32/41


4 - Top

GMT

Weld IndentationMaterial A

(Top)Material B


Test2 - Top 2 - Bottom 4 - Bottom

30%Limit

Peel Sample Weld Indentation (mm)

1.201.401.541.201.601.971.151.501.601.001.501.401.601.92

1.2/2.2

1.15/1.6

1.0/1.5

1.4/1.92

1.0/2.2

1.0/1.92

0.450.42

0.590.350.450.480.30

0.20

0.20

0.27

0.25 0.250.17 0.17 0.19

DP600DP980 (B)

----

--

----

--

-

590R-

DP600

0.19

0.31

DP780

DP600

-

0.480.36

0.360.420.46

0.25

0.200.160.20

0.55 0.58 0.85

0.33 0.36 0.310.28 0.260.27

0.30 0.29 0.320.17 0.20 0.21

0.260.25

0.68 0.66 0.44

0.31 0.31 0.470.18

0.54

0.31 0.27 0.32

0.51 0.44 0.42

0.310.480.210.13

0.18

0.20 0.220.15 0.18 0.16

0.19

0.25 0.28 0.26

0.450.43

0.21

0.620.43 0.40

0.60 0.42 0.740.65 0.37 0.490.75

DP980 (B)

DP600

---

TRIP800TRIP800

DP980

DP980 (B)

DP980 (B)DP980 (B)


DP600DP780DP750

DP780 (B)

590R (B)590R

DP600DP600

DP780 (B)

DP980

Mild

TRIP800

DP980 (B)DP980 (B)

DP600DP780

Mild

TRIP800TRIP800

DP980

DP750

590R

590R

DP600

590R (B)

4165r13d

4165r18d

4165r19d4165r20d

4165r14d

4165r15d

4165r16d4165r17d

4165r9d

4165r10d

4165r11d

4165r12d

4165r5d

4165r6d

4165r7d

4165r8d

4165r1d

4165r3d

4165r4d

4165r2d

0.45

0.68

0.28

0.450.460.440.20

0.92 0.30 / 0.660.30 / 0.58

0.480.58

0.36 / 0.660.35 / 0.480.30 / 0.450.42 / 0.58

Results Mechanical Testing AC


33/41


1.201.401.541.201.601.971.15

1.501.601.001.501.401.601.92

1.201.151.001.40

685.7790.3281.0685.7589.1

790.31248.9382.2

419.7589.1726.5419.7

4165r19a4165r20a

DP600

1687.7

1588.0

1101.01461.7

1069.2

1196.81871.01250.01836.8

5553.3

5838.3

4004.3

1283.81617.81866.4

2370.0

1304.82008.92744.6

3419.23349.2

5408.8

5624.7

4785.03616.0

6042.0

4897.8

4048.0

3550.2

Mechanical Verification - AWS D8.1M:2007Material A

(Top)Material B


TestCT AveragePeak Load

GMT

TS AveragePeak Load

D8.1TS

D8.1CT

1659.7

DP600DP600DP780

1818.5

1557.2

1912.71886.31531.8

2242.2

590R590R (B)

590R

TRIP800

DP600

DP750DP780 (B) 2555.51290.1

5053.76204.0

TRIP800DP980

DP600DP980 (B)

DP980 (B)

-

1452.72087.53076.2

DP980 (B)DP980 (B)

2493.3

TRIP800

DP600DP780 (B)

4327.0

1304.81557.21290.12493.3

-

-------

590R590R (B)

590RDP600DP600DP600DP780

DP750

3046.26527.0

3985.03921.3

790.31180.2

419.7382.2281.0589.1

1184.0

--

-

----

--

DP980 (B)

DP780TRIP800

DP980

MildMild

DP600

DP780 (B)TRIP800TRIP800

DP980DP980 (B)DP980 (B)

4165r15a4165r16a4165r17a4165r18a

4165r11a4165r12a4165r13a4165r14a

4165r7a

4165r8a4165r9a4165r10a

4165r3a4165r4a4165r5a4165r6a

4165r1a4165r2a

Results Mechanical Testing DC


34/41


Mechanical Verification - AWS D8.1M:2007Material A

(Top)Material B


TestCT AveragePeak Load

GMT

TS AveragePeak Load

D8.1TS

D8.1CT

1.201.401.541.201.601.971.151.501.601.001.501.401.601.92

1.201.151.001.40

685.7

419.7

382.2

790.3

1283.81617.81866.41304.8

589.1726.5419.7790.3

1248.9

685.7589.1790.3

1180.2

281.0

1611.31280.22348.2

1884.32668.0

589.1

419.7382.2281.0

3022.33422.2

1802.2

1763.32676.32843.21598.7

1085.84165r1d 3232.8

6906.36668.24004.76821.76326.07995.7

-

--

-

--

TRIP800

DP780DP750

DP780 (B)

DP600

590R590R (B)

590R

DP980 (B)

-

DP600

--

DP980

---

3060.36226.7

4647.55755.7

1290.12493.3

4179.0

7802.5

8193.7

3606.3

2555.51290.1

1557.2

1304.83813.74889.3

7711.8

2370.02493.33046.24004.3

1557.2

2744.6

2760.82976.2

2008.9

2242.2

959.8

2780.32010.0

-

DP980 (B)

DP600

---

-

DP980

DP750

DP600

DP980 (B)

DP980 (B)DP980 (B)


DP600DP780

DP600DP600

DP780 (B)

DP600DP600DP780

-

TRIP800

Mild

TRIP800TRIP800

DP980

Mild

TRIP800

DP980 (B)DP980 (B)

590R

590R590R (B)

4165r19d4165r20d

4165r14d

4165r15d4165r16d4165r17d

4165r11d4165r12d4165r13d

4165r18d

4165r7d4165r8d4165r9d

4165r10d

4165r4d

4165r2d

4165r5d4165r6d

4165r3d

Metallographic Inspection


35/41


1.15 mm DP780 Galvanized / 1.15 mm DP780 GalvanizedAC 7 DC 7



36/41


1.20 mm DP600 Galvanized / 2.20 mm DP600 GalvanizedAC 15 DC 15



37/41


1.40 mm DP980 Galvanized / 1.92 mm DP980 BareAC 18 DC 18

Phase II - Summary (1 of 2)


38/41


Weld Schedules AC and DC schedules specify different electrodes

Direct comparison of results difficult

DC schedules had lower gauge transition to large electrodes AC @ 1.60 mm vs. DC @ 1.30 mm Affected amount of visible surfacing cracking and measurable

indentation in materials between the transition gauges Material between 1.30 and 1.60 mm (Trials #3 & #8) Longer hold times for DC

Minor reduction in void formation (Trial #19) Nearly all schedules evaluated produced expulsion Indentation may predetermine peel weld size (Trials #11 & #19)

Phase II - Summary (2 of 2)


39/41


Visual surface inspection No evidence of surface cracking

Did not use magnification device

Most indentation measurements in excess of 30% limit DC slightly better due to electrode geometry

Mechanical evaluation All peak loads exceeded requirements of AWS D8.1

Many results 2x or 3x greater than requirements

Metallographic evaluation Over 50% of welds with surface cracks

More evidence of AC surface cracks than DC

Acknowledgements


40/41


Kevin Chan, Huys Industries simulation work on DCweld schedules

Wenqi Zhang, SWANTEC Software and Engineering

ApS technical support with SORPAS software

FOR MORE INFORMATION


41/41


Contact:Mike Bzdok, Project Manager(248) 945-4778

[email protected] Pakalnins(248) 576-7454

[email protected]

ARW Presentation

Documents

Transcript of ARW Presentation