Residual Stress Build UpBaseline NADCA TestDetermine how quickly stress builds?What happens when tensile drops?What other factors contribute?How virgin base H-13 is affected?

Baseline TestingPre - Dip tank testingvirgin specimenno surface treatmentspolished corners and sideProto X-rayinclude corners

Case Western specified measurement pointsbaselines

H-13Dip TankSpecimen2eachside7All corners square +.003 to -.003All corners have .010 radius

Cycles till measured0,10,100,500,1000,5000,10000,15000Dip tank testing no v or pImmersion aluminum12 seconds immersion24 seconds air coolWater based lube 50:1Repetitive cycles X-ray diffraction measuremicro hardness before and after readings - softeningmeasure corner crackingphotograph x-ray MEASURED surface area

H-13Dip TankSpecimen2eachside7All corners square +.003 to -.003All corners have .010 radiusPhotography not performed on this 1st specimen

Proto X-Ray Reading Criterialocation measurementsCorners 1,2,3,4,5,6,7,8Middle 1,3,5,73 points each corner (avg)3 points each middle (avg)45o at point #2 (middle) only for zero cyclesMeasurements in ksi -1ksi = 6.895MpaError range 5 with average 2 (zero-1000)Error range 8 with average 5 (5000 cycles)Error range 8 with average 4 (10,000 cycles)Error range 2 with average 1 (15,000 cycle)

Phase II Baseline Testing

H-13Dip TankSpecimenAll corners square +.003 to -.003All corners have .010 radius

Measured corners6ea per side x 4 = 24 pointsMeasured middle side 1,3,5,7Axial 3ea per side x 4 = 12Trans 3ea per side x 4 = 12

Total of 48 x-ray diffraction measurements from 36 locations 3.53.51.0Side 7Side 5Side 11.5Side 3

What the following data provesTensile relieved by crackingTensile rebuilds to higher levelsSubsequent cracking developsEach time tensile drops to lower level.

No Dip Cycles - BaselineAll but 4 measurements indicate polished compression

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 245o - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4Error +or- 1 to 3

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

8+5-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7+6+5+3-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1646159

2655356

3686362

4526148

5556453

6556750

7586350

8696669

Middle

1141115252531

3404230432530

5172720233942

7483929404526

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1414848

2494754

3474848

4304140

5394743

6575342

7424538

8515757

Middle

1121214192030

3303524332224

5112816203535

7373728383824

At 100 cycles tensile values have decreased slightly

1000 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1535553

2575155

3665848

4534945

5555652

6585347

7545752

8555958

Middle

1172419343632

3333428483033

5192821274131

7443928464530

At 1000 cycles tensile values are again increasing

2500 CYCLES

H-13 SpecimenCompressive

2500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1615354

2515150

3697164

4443636

5575857

6615450

7676461

867714871

Middle

1444244444244

3544240544240

5414242414242

7494636494636

At 2500 cycles tensile values are almost at same level as 10 cycles

10 CyclesAll compressive stress converts to tensile

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

8+5-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7+6+5+3-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1+64+61+59

2+65+53+56

3+68+63+62

4+52+61+48

5+55+64+53

6+55+67+50

7+58+63+50

8+69+66+69

Middle

1+14+11+15+25+25+31

3+40+42+30+43+25+30

5+17+27+20+23+39+42

7+48+39+29+40+45+26

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1+41+48+48

2+49+47+54

3+47+48+48

4+30+41+40

5+39+47+43

6+57+53+42

7+42+45+38

8+51+57+57

Middle

1+12+12+14+19+20+30

3+30+35+24+33+22+24

5+11+28+16+20+35+35

7+37+37+28+38+38+24

At 100 cycles tensile values have decreased slightly

500 CYCLES

H-13 SpecimenCompressive

500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 2Error +or- 1 to 2

1+53+55+53

2+57+51+55

3+66+58+48

4+53+49+45

5+55+56+52

6+58+53+47

7+54+57+52

8+55+59+58

Middle

1+17+24+19+34+36+32

3+33+34+28+48+30+33

5+19+28+21+27+41+31

7+44+39+28+46+45+30

At 500 cycles tensile values are again increasing

1000 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 3Error +or- 1 to 2

1+61+53+54

2+51+51+50

3+69+71+64

4+44+36+36

5+57+58+57

6+61+54+50

7+67+64+61

8+67+71+4871

Middle

1+44+42+44+44+42+44

3+54+42+40+54+42+40

5+41+42+42+41+42+42

7+49+46+36+49+46+36

At 1000 cycles tensile values are almost at same level as 10 cycles

5000 CYCLES

H-13 SpecimenCompressive

5000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 9Error +or- 3 to 8 range

1+73+70+70

2+64+53+58

3+72+72+70

4+53+62+69

5+83+87+81

6+69+76+60

7+81+87+65

8+66+68+6671

Middle

1+31+27+34+54+47+43

3+37+45+38+59+46+60

5+35+35+30+49+44+55

7+45+41+38+58+54+47

At 5000 cycles tensile values are almost at same level as 10 cycles

10000 CYCLES

H-13 SpecimenCompressive

10000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 6Error +or- 2 to 8 range

1+75+84+84

2+81+81+80

3+79+71+77

4+79+78+77

5+77+87+85

6+88+84+73

7+76+90+97

8+83+81+8671

Middle

1+32+35+42+40+53+49

3+33+39+37+59+31+56

5+10+41+23+48+75+13

7+39+59+51+53+55+51

At 10000 cycles tensile has increased above the 5000 cycle point

15000 CYCLES

H-13 SpecimenCompressive

15000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 2Error +or- 1 range

1+50+67+75

2+61+73+65

3+59+69+70

4+38+59+54

5+48+66+57

6+72+72+76

7+76+72+73

8+43+62+6571

Middle

1+32+34+30+50+52+50

3+37+37+23+37+31+29

5+27+34+26+50+55+47

7+45+41+33+52+53+46

At 15000 cycles tensile values move lower again

100 CyclesTensile stress values reduced by cracking

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 245o - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4Error +or- 1 to 3

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

85-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7653-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1646159

2655356

3686362

4526148

5556453

6556750

7586350

8696669

Middle

1141115252531

3404230432530

5172720233942

7483929404526

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 3Error +or- 2 to 3

1+41+48+48

2+49+47+54

3+47+48+48

4+30+41+40

5+39+47+43

6+57+53+42

7+42+45+38

8+51+57+57

Middle

1+12+12+14+19+20+30

3+30+35+24+33+22+24

5+11+28+16+20+35+35

7+37+37+28+38+38+24

At 100 cycles tensile values have decreased slightly

1000 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1535553

2575155

3665848

4534945

5555652

6585347

7545752

8555958

Middle

1172419343632

3333428483033

5192821274131

7443928464530

At 1000 cycles tensile values are again increasing

2500 CYCLES

H-13 SpecimenCompressive

2500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1615354

2515150

3697164

4443636

5575857

6615450

7676461

867714871

Middle

1444244444244

3544240544240

5414242414242

7494636494636

At 2500 cycles tensile values are almost at same level as 10 cycles

500 CyclesTensile stress again on the rise

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 245o - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4Error +or- 1 to 3

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

85-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7653-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1646159

2655356

3686362

4526148

5556453

6556750

7586350

8696669

Middle

1141115252531

3404230432530

5172720233942

7483929404526

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1414848

2494754

3474848

4304140

5394743

6575342

7424538

8515757

Middle

1121214192030

3303524332224

5112816203535

7373728383824

At 100 cycles tensile values have decreased slightly

1000 CYCLES

H-13 SpecimenCompressive

500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 2Error +or- 1 to 2

1+53+55+53

2+57+51+55

3+66+58+48

4+53+49+45

5+55+56+52

6+58+53+47

7+54+57+52

8+55+59+58

Middle

1+17+24+19+34+36+32

3+33+34+28+48+30+33

5+19+28+21+27+41+31

7+44+39+28+46+45+30

At 500 cycles tensile values are again increasing

2500 CYCLES

H-13 SpecimenCompressive

2500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1615354

2515150

3697164

4443636

5575857

6615450

7676461

867714871

Middle

1444244444244

3544240544240

5414242414242

7494636494636

At 2500 cycles tensile values are almost at same level as 10 cycles

1000 CyclesTensile stress approaching values seen at 10 cycles

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 245o - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4Error +or- 1 to 3

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

85-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7653-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1646159

2655356

3686362

4526148

5556453

6556750

7586350

8696669

Middle

1141115252531

3404230432530

5172720233942

7483929404526

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1414848

2494754

3474848

4304140

5394743

6575342

7424538

8515757

Middle

1121214192030

3303524332224

5112816203535

7373728383824

At 100 cycles tensile values have decreased slightly

1000 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1535553

2575155

3665848

4534945

5555652

6585347

7545752

8555958

Middle

1172419343632

3333428483033

5192821274131

7443928464530

At 1000 cycles tensile values are again increasing

2500 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 3Error +or- 1 to 2

1+61+53+54

2+51+51+50

3+69+71+64

4+44+36+36

5+57+58+57

6+61+54+50

7+67+64+61

8+67+71+4871

Middle

1+44+42+44+44+42+44

3+54+42+40+54+42+40

5+41+42+42+41+42+42

7+49+46+36+49+46+36

At 1000 cycles tensile values are almost at same level as 10 cycles

5000 CyclesTensile stress continuing increase

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 245o - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4Error +or- 1 to 3

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

85-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7653-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1646159

2655356

3686362

4526148

5556453

6556750

7586350

8696669

Middle

1141115252531

3404230432530

5172720233942

7483929404526

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1414848

2494754

3474848

4304140

5394743

6575342

7424538

8515757

Middle

1121214192030

3303524332224

5112816203535

7373728383824

At 100 cycles tensile values have decreased slightly

1000 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1535553

2575155

3665848

4534945

5555652

6585347

7545752

8555958

Middle

1172419343632

3333428483033

5192821274131

7443928464530

At 1000 cycles tensile values are again increasing

2500 CYCLES

H-13 SpecimenCompressive

2500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1615354

2515150

3697164

4443636

5575857

6615450

7676461

867714871

Middle

1444244444244

3544240544240

5414242414242

7494636494636

At 2500 cycles tensile values are almost at same level as 10 cycles

5000 CYCLES

H-13 SpecimenCompressive

5000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 9Error +or- 3 to 8 range

1+73+70+70

2+64+53+58

3+72+72+70

4+53+62+69

5+83+87+81

6+69+76+60

7+81+87+65

8+66+68+6671

Middle

1+31+27+34+54+47+43

3+37+45+38+59+46+60

5+35+35+30+49+44+55

7+45+41+38+58+54+47

At 5000 cycles tensile values are almost at same level as 10 cycles

10000 CyclesTensile stresses at highest levels

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 245o - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4Error +or- 1 to 3

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

85-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7653-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1646159

2655356

3686362

4526148

5556453

6556750

7586350

8696669

Middle

1141115252531

3404230432530

5172720233942

7483929404526

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1414848

2494754

3474848

4304140

5394743

6575342

7424538

8515757

Middle

1121214192030

3303524332224

5112816203535

7373728383824

At 100 cycles tensile values have decreased slightly

1000 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1535553

2575155

3665848

4534945

5555652

6585347

7545752

8555958

Middle

1172419343632

3333428483033

5192821274131

7443928464530

At 1000 cycles tensile values are again increasing

2500 CYCLES

H-13 SpecimenCompressive

2500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1615354

2515150

3697164

4443636

5575857

6615450

7676461

867714871

Middle

1444244444244

3544240544240

5414242414242

7494636494636

At 2500 cycles tensile values are almost at same level as 10 cycles

5000 CYCLES

H-13 SpecimenCompressive

10000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 6Error +or- 2 to 8 range

1+75+84+84

2+81+81+80

3+79+71+77

4+79+78+77

5+77+87+85

6+88+84+73

7+76+90+97

8+83+81+8671

Middle

1+32+35+42+40+53+49

3+33+39+37+59+31+56

5+10+41+23+48+75+13

7+39+59+51+53+55+51

At 10000 cycles tensile has increased above the 5000 cycle point

15000 CyclesTensile stress drops off again by larger amount when visible cracking develops

ZERO CYCLES

H-13 SpecimenCompressive

No CyclesTensile

Axial KSITransverse KSI - Point 245o - Point 2

CornerError +or- 2 to 4Error +or- 2 to 4Error +or- 1 to 3

1-14-12-11-56-36

2-17-20-19-64-48

3-4-8-5-64-36

4-8-11-9-56-30

5-5-7-9-51-23

6-13-20-18-53-38

7-12-11-13-64-42

85-1-6-55-25

Middle

1-9-14-16-61-61-55-38

3-8-612-65-56-61-37

5-22-20-21-53-59-56-40

7653-48-51-58-22

Polishing after machining creates compressive values.

10 CYCLES

H-13 SpecimenCompressive

10 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1646159

2655356

3686362

4526148

5556453

6556750

7586350

8696669

Middle

1141115252531

3404230432530

5172720233942

7483929404526

After only 10 cycles all readings indicate high tensile levels

.

100 CYCLES

H-13 SpecimenCompressive

100 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1414848

2494754

3474848

4304140

5394743

6575342

7424538

8515757

Middle

1121214192030

3303524332224

5112816203535

7373728383824

At 100 cycles tensile values have decreased slightly

1000 CYCLES

H-13 SpecimenCompressive

1000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1535553

2575155

3665848

4534945

5555652

6585347

7545752

8555958

Middle

1172419343632

3333428483033

5192821274131

7443928464530

At 1000 cycles tensile values are again increasing

2500 CYCLES

H-13 SpecimenCompressive

2500 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 2 to 4Error +or- 2 to 4

1615354

2515150

3697164

4443636

5575857

6615450

7676461

867714871

Middle

1444244444244

3544240544240

5414242414242

7494636494636

At 2500 cycles tensile values are almost at same level as 10 cycles

5000 CYCLES

H-13 SpecimenCompressive

15000 CyclesTensile

Axial KSITransverse KSI

CornerError +or- 1 to 2Error +or- 1 range

1+50+67+75

2+61+73+65

3+59+69+70

4+38+59+54

5+48+66+57

6+72+72+76

7+76+72+73

8+43+62+6571

Middle

1+32+34+30+50+52+50

3+37+37+23+37+31+29

5+27+34+26+50+55+47

7+45+41+33+52+53+46

At 15000 cycles tensile values move lower again

What was confirmed? Cycling of tensile stresses and micro cracking occurs on first 10 shot of unprotected steel. Virgin steel with no surface treatment and only polished compression, changes rapidly to tensile stresses increases between 100 & 10000 cycles Visible tensile stress reading at 15000 occurs Beneficial prior to use to induce high levels of subsurface compressive stress values when die is NEW to prevent initial cracking.