PROGRESS REPORT

ON

CORRELATION OF LABORATORY TESTS WITHFULL SCALE SHIP PLATE FRACTURE TESTS:

A STUDY OF STRAIN GRADIENTS

BY

E.P.KLIER F.C.WAGNER,J.L.FISHERandM. GENSAMER

Penn.wlvaniaStateCollegeUnderBureauofShipsContractNObs-31217

COMMITTEEON SHIPCONSTRUCTION

DIVISIONOF ENGINEERINGAND INDUSTRIALRESEARCH

NATIONALRESEARCHCOUNCIL

MTRB LIBRARY

ADVISORYTO

SHIP STRUCTURE COMMITTEE

UNDER

BureauofShips,NavyDepartmentContractNObs-34231

SERIAL NO. SSC-17

COPY NO. .! ‘.?.. .

DATE:JUNE 8,1949

CABLEADDRESSNARECO. W..hi.@o.. D. C.

NATIONAL RESEARCH COUNCIL2101CONSTITUTION AVENUE, WASHINGTON, D.C.

E.t.bli.h.d in 1916by th? h,.ti..al A.wlmm’of science,underits Conmsd.n.lCharterand Wzanizedwith the Cmmraticmof the Natimml?=i..tific

and TechnicalWcietksof the united Sites

DIVISIONOF ENGINEERINGAND INDUSTRIALRESEARCH

Jone 8.1S49

Chief,Bureauof ShipsWfy DepartmentWashington2.5,D. C.

De&r Sir:

Attaohedis ReportSerialifo.SS-17,entitlednCorrelationof LaboratoryTestswith Full %ale ShipPlateI’raoturel!eete:A Studyof StrainGradiente.” Thie reporthes beensubmittedby the oontraotorae a ProgreesReportofthe work done on ResearohProjeotSR-96underContre,otNObe-31217betweenthe Bureauof Ships,Navy Departmentand PennsylvaniaStateCollege.

?he reporthas been reviewedand aooeptancerecom-mendedby representativesOf the COmmitteeon ship CO~truotion~Divieionof Engineeringand IndustrialRessarch,FRC, Inamordance with the texmeof the contractbetweenthe Bureauof Shipe,Mavy Departmentat the NationalAoademyof fbi~oee.

CRS:mhEnoloeure

~/~::2

9C. RichardSoderberg,ChairmanDivisionof EngineeringandIndustrialResearoh

PREFACE——

The NavyDepartmentthroughthe Bureauof Ships is distributingthis reportto thoseagenciesand individualswho”were actively,associatedwith the researchwork, This reportrepresentsa part of the researchwork contractedfor underthe sectionof the Navy!sdirective‘Ito investigatethe designand constructionof weldedsteelmerchantvessels.11

The distrfoutionof thisreportis as ?O11OWS:

CopyNo. 1 - Chief,Bureauof Ships,Navy DepartmentcopyNo. 2 - Dr. D. W. Bronk,Chairman,NationalResearchCouncil

Committeeon Ship Construction

copy No. 3 ,-V. H. Schnee,ChairmanCopy ~!O. 4- J. i.’BatescopyNo. 5 - H. C. BoardmanCopy No. 6 - Paul FfieldcopyNo. 7 - M. A. GroesmanCopyNo. 8 - C. H. Herty,Jr.Copy No. 9 - A. B. KinzelCopyNo. 10,.-J. M. Lessens ~‘copyEo. U -”G. S. MikhalapovCopy No. 12.- J. Ormondroyd ‘“copy No. 13 - H. W. PierceCopy No. U - E. C. SmithCOPY IIOe 15 - T. T. I!atsonCOTJ No. 16 . Finn Jonaseen,ResearchCoordinator

Membe:-sof ProjectAdvisoryCommitteesSR-25,SFi-f?7,SR-92,SR-96,SR-98,SR-99,SR-1OOand S%101

COPY No. 16 - Finn Jonassen,Chairmencopy NO. 17 - R. H. AbornCopyNo. 18 - L. C. Blbbercopy No. 5 - H. C. Boardmencopy 1?0. 19 - T. J. DolanCopy No. 6- Paul.Ffieldcopy No. 7 - M.’”A.Grossman “.CopyNO. 8 - C. H. Herty,Jr.

,.,,,.’

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copyNo. 10 - J. M. Lessens ,.

Cow No. 21 - M. W. Lightner. “

copy No. 11 - G. S. l!i~lialapovcopy No. 12 - J. OrmondroydcopyNo. 22 - R. E. PetersonCopyNo. 13 - H. W. Piercecol?y NO. 23 - R. L. RickettCOpyNO. 14 - E. C.’SmithcopyNo. 15 - T. T. EatsonCOPY !{0. 24 - A. G. Bissell,Bureauof Ships,LiaisonCOpy1“’0.25 - MathewLetich,America:Bureauof Shipping,Liaison

-+???d%.—=—’—+$~ z~ “&; -; $.j-.;~u

COPy ]!0.26 - JamesI!lcIntosh,Ut S. OohstCiua,rd,LiaisonCOpy 1~0.27 -~ . . 4. J& -.~ -“~/@-LcopyNo. 28 - Comdr.R. D. Schmidtrnan,U. S, CoastGuard,LiaisoncOpY NO. 29 - ‘I. L. SOO-HOO,,Btu~eauof.Ships,Lia.j’soncopyNo. 30 - Wm. Spraragen,’WeldingResearchCouncil,LikisoncopyNo. 31 - R. E. Wiley,Bureauof Ships,I,iaj.s,onCOpy}~o.32 - J. L. Wilson,,@ericanBureauof Shipping,Liaison

Ship StructureCommittee

copy No. 33 - Rear AdmiralEllisReed-Hill,USCG - Chairmancopy1!0.34 - Rear AdmiralChs.rleeD.J!heelock,USN,Bureauof ShipscopyNo. 35 - BrigadierGeneralPaul J?.Yonnt,War DepartmentCOn7 No. 36 - Ca~tainJ. L. McGui~an.!J.S. ?:!aritimeCommissionco;> NO. 37 -copyN’o. 3 -

copy NO. 38 -copyro. 39 -copyNo. 40 -copy No. 28 -copyNO. 41 -COpY }?0.42 -COpYNo. 25 -COpy No. 26 -copyNo. 43 -copyNo. 44 -copy No. 31 -COpy !:0. 32 -COpy fro.16 -copy Ho. 45 -COpyNo. 46 -Copyi~o.30 -

D.’P. Brown,‘Americ~nBureau”of ShippingV, H. Schnee,Committeeon Ship Construction- Liaiaon

Ship St,ructmeSubcossnittee

CaptainC. M. Tooke,USN,Bureauof Ships,ChairmancaptainR. A. Hinners,lJSN,DavidTaylorModelBasinComdr.R. H. Lambert,USN, Bureauof ShipsComdr.R. D. Schmidtman,USCG,LT.S.CoastGuardHeadquartersW, G. Frederick,U. S. MaritimeCommissionFubertKempel,Ofiiice,Chiefof Transportation?War DepartmentMa.thewLetich,AmericanBureauof ShippingJamesIicIntosh,U. S. CoastGuardR. M. Robertson,Office,l’avalResearch,U. S. NavyV, II.Russo,U.,S. MaritimeCommissionp, Z. WileY,Bureauof Ships,U. S. NavyJ. L. Wilson,AmericanRureauof ShippingFinn Jonassen,LiaisonRepresentative,NRCE. H. Davidson.LiaisonRepresentative,AISIPaul Gerhart,~iaisonRepr&sentative,AISIwm. Spraragen,LiaisonRepresentative,~JRC

Navy Department

copy1!0.f+7- Comdr.R. S. Mandelkorn,LEiT,ArmedForcesCopyNo. 24 - A. G. Bissell,Bureauof Shipacopy NO. 48 - A. Amirikian,BureauOf Yards and DOcksCODY!?0. L9 - J. T. Jenkino,Bureauof ShipsCo;yNo. 50-copyNo. 51 -COpy No. 52 -copy NO. 53 -copy NO. 54 -Copies55 andcopy NO. 57 -cOpy NO. 58 -Copyi!o.59 -copyNo. 60 -

NoahKahn,lte~York NavalShipyardE. ii.MacCutcheon,Jr., DavidTaylorModelIT.R. Osgood,DavidTaylorModelBasinN. E. Promisel,Bureauof AeronauticsJohn Vasta.Bureauof Ships

Special“PieaponsProject

Basin

56 - U. S.”FavalEngineeringExperimentStationNew York XavalShipyard,MaterialLaboratoryIndustrialTeeti.ngLaboratory,PhiladelphiaNavalShipyardPhiladelphiaNayalShipyardSan FranciscoNavalShipyard

copyNO. 61 -David ~aylorModelBasin,Attn:Libra~Copies62 and 63 .-PublicationsBoard,Navy llepartrientvia RuShips,Code 330cCopiee&+ and 65 - T’ecbnicalLibrary,Bureauof Ships,Code 337-L

U. S,,Cpait”G&-d

Copy No. 66 -copy No. 67 -copy1?0.6s -COPyNO. 69 -

copy No, 70 -

CopyNo. 71 -

CopyNo. 18 -

copy No. 8 -copy No. IA -

COpy No. 72 -copyNo, 73 -

Copy1!0.75 -co~y i!O. 8 -cOpy NO. 76 -copy No. 77 -copy No. 7$3-copy WO. 79 -COPy No. 80 -CopyNo. 21 -copy No. 81 -COpy NO. 16 -copy Ho. 82 -

CaptainR. B. Lank,,Jr..,USCGCapta+nG. A. Tyler,I$3CGTestingand D,evslopmeqtDivision,U. S. CoastGuardAca+emy,New London

,,U. S. MaritimeConimi3sion

E. E. Martinsky

Representativesof AmericanIronand Steel InstituteCommitteeon ManufacturingProblems

C. M.

L. C.C. H.3. c.

C> A.

Parker,Secreta~’,GeneralTe@nical Committse,AmericanTronand SteelInstituteBibber.Garnegie-IllinoisSteelCorD.Herty,“Jr.,B&,lilehemSteel~ompany”.%iith,,RepublicSt@l Company

WeldingReeearch.?~uncil

Adama CODYiio.7LIiierettChapman Co;f No: 36

Committeeon ShipSteel

P.,F. MehljChairmenC. H. Herty,Jr., Vice ChairmanWm. M. Baldwin,Jr.Chas.S. BarrettR.,11.BrickS. L, HoytI. R. KramerM, W. LightnerT. S. WashburnFinn Jonassen,TechnicalDirectorR, H. Rari.ngjTechnicalSecretary

- LaMotteGrover. Wn. Spraragen

Copy ITo.83 - C. R. Soderberg,Chairman,Div.Eng.& Ind.Research,NRCCopy No. 3 - V. R. Schnee,Chairman,Committeeon Ship Constructioncopy No. 16 - Finn .lonassen,ResearchCoordinator,Committeeon Ship ConstructionCOpy NO. 84 - E. P. Klier,Investigator,ResearchProjectSR-96COpy No. 85 - F. C. Wagner,Investigator,ResaarchProjectSR-96copy Noe 86 - J. L. Fisher,Investigator,ResearchProjectSR-96COPY No. 87 - 11.Gensamer,Inveetiga.tor,ResearchProjectSR-96Copy ~iO. 88 - S. T. Carpenter,Investigator,ResearchProjectSR-% .”copy NO. 89 - L. J. Ebert,Investigator,ReeearchProjectSR-99copy No. 10 - J. U. Lessens, Investigator,ResearchProjectS~-101

—. —

copy No. ‘Y1- C. W. MacGre&or,Investigator,ResearchF’rejectSI?-102CopyNo. 91 - C~ B. Voldrich,Investigator,ResearchProjectSR-1OO ‘.COPYNO. 92 - ClarenceAltenburger,GreatLikesSteelCompanycopy No. 93 - A. B. Eagsa,r,Suu Oil CompanycopyNo. 94 - E. L. Cochrane,MassachusettsIneti.tuteof Technol.oflJcopy No. 95- GeorgeEllinger,NationalBureauof StandardsCOpY ~~0.96- M. F, Hawkes.CarneRieInstitute”of Technolom

Low,”Jr.j GeneralElect>icCompanyNewmark,Un5.versityof IllinoisNorton,MassachusettsInstituteof TechnologyReich,GeneralElectricCompanyRohl,Carnegie-IllinoisSteelCorp.Roop,SwarthmoreCollegeStout,LehighUniversity

Copj NO. 9’7- W. F. Hess,fieneeel~erPo~ytechr,icInetitute--CopyNo. ‘3$3- 0. J. Horger,Timken RollerBearingCompanycopy No. 99 - Bruce JOhDS ton, Frit ?, Laboratory,’;Lei~ighUnj.versity ,copyNo. 100 - P. E. Kyle,CornellUniversityCopy No. 101 - J. R.copyNo. 102 - N, M,Copy No. 103 - J. T.Copy No. 10L - W. A.CopyNo, 105 - L. J.COpy NO. 106 - W. P.CopyNo. 107 - R. D.copy NO. 108 - SaylorSnyd&, Ca&e.gie-Illin~iaSteelCorp.CopyNo. 109 - J. F. Wal.laoe,WatertownArsenallaboratory (staff)copy No. 110 thru 134 - Sir Chas.Wright,British.Toint,.ServicesMiesion(NavjJcopy No. 135 - Carl A. Zapffe, CarlA, ,ZapffeLaboratoriesGOpyNO. 136 - InternationalNickelCo., Ino.,Attn: ‘f.F. ,ArmstrongCopyNo. 137 - TransportationCorpsBoard,Brooklyn,New YorlcCopies138 tbru 142 - Libraryof“Congresa”via Bureauof Ships,Code 330cCopyI!oJ L!+:- File Copy,Committeeon Ship Steelcopyno.“l&+- NACA,Attn: ,Ma~erialsResearchCoordination,U. S. ~avyCopiesU5 thru 149 - Bureaiif Sh;ps

‘::=v+;_:~y&’ %4copy No. 150 -

%%%: :% -4. ~ - C.&+-AQ-n L+A+LJJ%z.:f+copyNO. 153 -&v da% %6 %+Q&@zz d/J’h-q .copy No. 154 - ~.~.M\LLGQ-CA-V=V@@M r.c+aw ea. f,. ~ +( ’.>-=

Copy No. 155 ..-0...D .~ c1.u.jx$copy No. 155 -Copy No. 156 - -copy 1!0.157 -

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copyNo, 15s -CopyNo. 159 -copy No. 160 -COPY 170. 161 - ,,COPYFO. 162 -COpy,No. 163 -COpy No, 16A -CopyNo. 165 -copyNO. 166,,-.COpyNo. 167 -COpyNO. 166 -COpy Poe 169 -copy No. 170 -COPY No. 171 -

PROGRESSREPORT

Navy Bureauof ShipsContractNObs-31217

ProjectSR-96

COBRELATIONOF LAEORATOIWTESTSWITHFULL SCALESHIP PLATEFIL4CTURETESTS:

A STUDYOF STILLINGRADIENTS.

By: E. P. KlierF. C. 7iagnerJ. L. FisherM. Gensemer

*

MineralIndustrialExperimentStationSchoolof MineralIndustriesThe PennsylvaniaStateCollegeStateCollege,Pennsylvania

@&e

ABSTRACT

LIST OF TABLRS

LIST OF FIGURES

I - PUBIOSE

II - INTRODUCTION

A - ContinuityB - Theoryc - HistoricalD - FactsBearingon the ProblemE - Personnel

III - MATERIALS

IV - METHODSOF TEST

A - HardnessTestsB - MetallographicTestsC - X-Ray.halysis

v - RESULTSAlW3DISCUSSION

A- X-RayAnalysisB - HardnessGradientsof BrokenCharpyBarsc - HardnessGradf.entsof Bent CharpyBarsD- HardnessGradientsof LargeFracturedPlatesE - Metallography

W - CONCLUSIONS

i

ii

iii

1

1.

4

4

6

u

Vj

-i-

ARS1’RACT——

Straingradientsnormalto fracturesurfaceswere determined.Theee

fracturesurfaces were developedunderthe followingconditionsof test:

(1) V-notchCharpybarsbrokenby impactat variouslocationswithinthe

transitionzone,(2) V-notchCharpybrs bent,but not completelybroken,

by impactabcvethe transitiontemperature,(3) S1OW bendScbdt tYPebars

brokenbelowthe transitiontemperature,and (L) 72-inchwide,centernotdb

tensilespeoimensbrokenwith ductileand brittlebehavior.

The straingradientswere studiedby meansof hardnesstests,metallo-

graphicmethodsand X-rayanalysis.

It is concludedthat true cleavageseparationis not accompaniedby a

measurablestraingradientbut most ‘Ibrittle!!or Itcleavagettfractures,so

classifiedon the basisof grossappearance,containsomeareasseparatedby

a shearmechanism.

,’.’

Table1

Table2

Table3

,.!,

?:

..,.

;.-11-

LIST OF TABI@,. .,,.

.). ,

~

ChemicalCompositionof the Steels 16

FractqrePhenomenain.CharpyV-Notch 17

Test Bars

FracturePhenomenain LnrgePlate 18

Specimens

.,.+

,,, ,

,,.. .

,,

... ,

Figure 1

Figure:2

Figure 3

Figure ~

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure10

Figure11

Figure 12

Figure13

Figure1/,

- iii -

LIST OF FIGUTUIS*

IdealizedFormsof StrainGradient. 19

X-rayPnttoins”‘SteelA. 20

The FractureMidwayThroughthe SpecimenSteelDr. 21

This is a ftil.yductilespecimen.(cf.Figures26 & 27).

The FractureMidwayThroughthe SpecimenSteelC.This

is a fullybrittlespecimen.

HardnessContours- Steelc.

energyabsorption3 ft. lbs.

HardnessGradient- SteelC.

energyabsorption3 ft. lbs.

HardnessContours- SteelE.

ene~gyab~orption7 ft. lbs.

HardnessGradient- SteelE.

energyabsorption7 ft. lbs.

(cf.Figures5 & 6),

Testedat -22°F;

Testedat -22°F;

Testedat 36°F;

Testedat 36%;

The Charecterof the Fractureat the Baeeof the

NOtchSteelE. (cf.Figures7 & 8).

The FractureNlidwayThroughthe Specimen

SteelIi. (cf.Figwes 7 & 8).

The Fractureat the Back of the Specimen

SteelE. (cf.Figuree7 & 8).

HardnessContours- SteelDr. Teetedat -39%;

energyabsorption10 ft. lbs.

HardnessGradient- SteelDr. Testedat -3903’;

energyabsorption10 ft. lbs.

HardnessContoure- SteelC. Teated at 50°F;

energyabsorption13 ft. lbs.

22

23

’24

25

26

27

28

29

30

31

32

Figure15

Figure16

Fignre17

Figure18

Figure19

Figure20

Figure21

Figure22

Figure23

Figure24

Figure25

,,, Figure26

Figure27

-iv-”

HardneesGradient- SteelC. Testedat 50%7;

energyabsorption13 ft. lbs.

HardnesaContours- SteelE. Teatedat 75°F;

energyabsorption16 ft. lb?.

Hardness‘Gr~&ient- SteelE. Testedat.75QF;

energyabsorption

HardnessContours

energyabsorption

HardnessGradient

energyabsorption

HardnessContouw

energyabico@ ‘.zn

HardnessGrddiont

energyabsimpti.on

HardnessContours

energyabsorption

HardnessGradient

energyabsorption

HardnessContours

energyabsorption

HardndssGradiQr,t

energyabsorption

Hardnese”Contours

energyabsorption

Hardn6ssGradient

energyabsorption

16 ft. Ibs .

- StselDr. Tested,at 16°F;

27.5ft. lbs.

- SteelDr. Testedat 16°F;

27.5ft. ibs.

- Steel I)?’.Testedat 64°F;

46.5ft. Ibe.

-“SteelDr. Teetedat 64%;

46’.5ft. lbs.

- SteelC. Te.atedat 113°F;

52ft.lbs.

- SteelCo Testedat 113°F;

52 ft. Ibs.

- SteelE. Testedat 17001’;

54 ft, lbs.

- SteelE. Testedat 170°F;

54 ft. lbs.

- SteelDr.,Testedat 1.26°F;

30.5ft. lbe.

-SteelDr. Testedat 126°F;

30.5ft. lbs,

Page

33

34

35

36

37

3$

39

40

41

42

43

44

45

.-v -

Figure28 “ H.ardness’CcnItours’- Steel.C. Testedat 212°F;.

energyab~orption+30ft. lbs.

~Figure29 HdrdfiessGradient.- Ste.elC. Testedat 212%;

energyabsorption80 ft. lbs.

“’Figure30 HardnessContours- SteelE, Teetedat 212°F;

energyabsorption7TIf%, lbs.

Figure31 HardnessGradient-SteelE. Teetedat 212°F; ‘

energyabsorption70 ft. lbs.

Figure32 HardneasContours- SteelC. Testedat 212°F;

angleof bend = 9°, no crackformed. Kinetic

Energyof Hammera 13 ft. lbs.

Figure33 HardnessContours- SteelC. Testedat 212°F,

angleof bend s 22°, emallcrackformed. “‘

KineticEnergy.of Hhmmers 34 ft. lbs.

‘Hartiess.Contours-’SteelC, Testedat 212°F,Figure3.!+

angleof bend : sgo, crackthrough1/3 of section.

KizleticEner~ of Hammer= 54 ft. lbs.,,

Figure35 Photographof PlateC-3.

Figure36 “‘

Figure37

:Figure38 ‘ ‘“’

Figure39

.~Figure40

Figure41

Figure42

Figure43

Line Drawing.ofFlatec-3,

HardnessContours- SpecimenNo. 1; PlateC-3.

HardneseContours- SpecimenJJo.2; PlateC-3.

HardnessContours- SpecimenNO. 3, PlateC-3.

HardneesContours- SpecimenNo. 4,”PlateC-3.

Photographof Plate22-IX. ,.

Line”Drawingof Plate22-IK.

Hardness..Contouis- SpecimenNo: 1; Plate22-I.K.

I-&&

46

47

@

49

50

51

52

53

‘5h

54

55

55

56

57

%

58

.—

-vi-

Figure.&l+ HardnessContours- SpecimenNo. 2, Plate22-M.

Figure.45 HardnessContours-SpecimenNo, 3, Plate22-IX.

Fi==e 46 HardnessContours-

Figure1+7 HardnessContours-

Figure48 Photographof Plate

Specimen

Specimen

N-l+A.

Figure49 Line Drawingof PlateN-l-A.

Figure50 HardneseContours- Specimen

Figure51 HardnessContours- Specimen

Figure52 HardnessContours- Specimen

Figure53 HsnxlneseContours- Spatimen

No. L, Plate22-lK.

No. 5, Plate22-lK,

II?O.1.,PlateN-1-A.

No. 2, PlateN-l-A.

No. 3, PlateIT-1-A.

NO. 4, PlateN-l-A.

Figure54 DeformetionTwinsin SteelC. NitalEtch x 6CXJ.

Figure55 StrainLinee in SteelDr. NitalEtchx 600

Fignre56 The Fracturefo~ SpecimenI!o.4 Plate22-IK

showingDeformationTwinsand Transitionfrom

Brittleto DuctileFailuro. NitalEtch x 500.

The Fracturefor SpecimenNo. 5 Plate.?2-IK

showingBritt3.e cracksof inter-endintra-granul.ar

Figure57

Figure58

Figure59

types. ]IitalEtch

AnotherRegionfor

Nitd Etch x 500.

x 500,

SpecimensNo. 5 Plate22-IK.

Characterof theFracturein SpecimenNo. 4

Plate22-lK. NitalEtch x 500.

&g

59

59

6C

60

61

62

62

63

63

64

65

66

67

68

69

7’0

—

I PWRPOSE

The purposeof this investigationwas to determinethe

the straingradient”at brittle“fracturesand at

II INTRODUCTION

J1-Continui@

characterietiesof

ductilefractures,

In the ProgressReport~of September15, 1946 “itwas indicatedthat a

reportwas beingpreparedrelatingto the etudyof etraingradientsas re-

vealedby hardneesmeasurementson impactbara fracturedat varicuslevaleof

energyabsorption.Th~e initialwork has been expandedto inolude(1) compar-

able testson lar’gefract~ed platee(2)X-Rayanalysesof strainat fractured

surfacesand (3) metallcgraphic

abovework is reportedhere.

B- ‘1’heory

examinationcf fracturedsectione. All of the

In attemptingto rationalizethe differe.nce,betweenbrittleand ductile

behftvicrin steel,,it has been s.uggeetedthat impcrtantinformationmightbe

gainedby an extensivestudycf straingradientsnormalto the fracturesur-

face. This suggestionis basedon twa facts:(1) a ductilefractme is

associatedwith a much higherenergyabsorptionthan a,brittlefractureand

, (2) the intensityand extentof plastic,strainare ind,icesof the energy

abeorpticn.Thus a studybasedon fact (2) couldconceivablyprovidedatato

explainfact (1),whichis the eseencecf the brittlechipplateprcblem.

Sinceit ie knownthat tbe energyabeorbedb>]pl~tic strainingincreaaes

witliboth the volumeof strainedmetaland tlieintensityof the strain,it

(1) - Numbersreferto itemsin Bibliography

-2-

,.,, .followsthat brittlebehavior,as contrastedwith ductilebehavior,must be

associatedwith”either(1)a smaller.voltie of strainedmetalor (2) lower

strainintensity.” F&ui% 1 schematicallyiQ@trates thesetwo possiblecliffer-

encesbetweenductileand brittlefractures.,.,.... ....,..,.,,

In Figure1(a),the strainintensityat the fracturesurf!aceis repre-

sentedas being constsiitfor all fractures,brittleand ductile. But the

ductile”fractureis representedby the gradualstraingradient,and will, there-

fore;be’associatedwith’a largevolumeof strainedmetaland..coneequentily

a largeefiergyabsorption;‘thebrittlefractureis representedby the steep

straingradientand will,therefore,be associatedwith’a smellvolumeof

strained‘metal“andconsequentlya smil~eoergyabsorption.:.ThusFigure1(a)

illustratesalternative(1)‘above.Alternative(2) is illustratedby Figurel(b).

Here,the strainintensityat the fracturesurfaoeis representedas beinghigh

for ductilefracturesand low for brittlefractures.Sinceenergyabsorption

increaseswith intensityof plasticetrain,it followsthat the fracture‘“”’

associatedwith high strainintensitywill absorba largesmovntof energyand

will be ductile,whilethe fractureassociatedwith the low strainintensity,:

will not absorbmuch energy,end will be brittle.,., ,,

(Fj.g,~e1 ~nd the,’subsequentdata of this reportassume;trainto be a,,,, .,linearfunctionof hardness. While this is not strictlytrue,it is a satis-

factoryapproximation,and ,straingradientsare representedin thisreportby,.

hardnessgradients),.,,.. ,.

c - Historical “ ., ,,...

‘Theextentof”plasticstrain“inthe iinpauttest hasbeen sttiie’dby

SauerwaldandWieland2,Moser3and others4)5> 6. Reviewsof the notch impact

,,,

-3-

test havebeen made by Fettweiss7$

and.MacGregorand Fisher . A studyof these

worksrevealsthe following:

(1) No extensiveanalysi.eof straining

of high sensitivity.Thus details

may have escapeddetection,

has been’undertaken

abo.~tthe vel~e of

(2) h’ocorrelatedanalysisof the volumeof strainedmetal

by method.s

st,rai.nedmetal

developedat

variauspointsin the transitionregionhas been publj.shed.This iS

an importantgap to be filled.

The presentwork is intendedto supplydata on both of thesepoints;

D - FactsBearinuon theProbl.6m—-. ——

Due“tothe characterof matter,any subs~ance;to a gre~teror Iess extent,,..

will functionas a “diffractiongratingfor X-rays. In ~~1 instancesof diffrac-,’

tion,the samefundamentalfactorsare operative,but optimumconditionsobtain

when the materialto be invcatig,clxxlhas a well developedspacelattice. Wlen

such is the case,and disregardingthe effectsof grainsize,well a:~i:edmaxima

in the diffractionspectraarisefor a giventype of spacelatticeat rtgor-

oualydefineddiffractionangles. Manyfactorscontributeto the finalappear-

anceof the individualspeetrallines,but thosefactorswhich alterthe appear-

ance of a givenlineas a functionof pinsticstrains.resomewhatlimited. This

wouldserveto decreasethe uncertaintyin the evaluationof a givenpattern

exceptthat$unfortunately,no one-to-onecorrespondencehoe everbeen ascer-

tainedas existingbetweenany of tho factorsmeasureda~d the degreeof plastic

strain. For instance,the obtainingof cliffused lineswhich is frequently

takenas indicatinga stateof plasticstrn.incan resultfrom chemicalcomposi-

tiongradients,elasticstraingradients,particleeizeand,certainlynot least

—.

important,externalgeometryof

of a fracturesurfacethislast

usuallycannotb,e

certainlypresent

be important.

E - Personnel

-4-

the cliffractj.ngsurface. In the exarnine.tion

factormay be a most importantfactor,which

modified. The effectsof

in a plasticallydeformed

elasticstraingradientsare most

metal,whileparticlesizemay well

The staffparticipatingin thiswork consistedof:

M, Gensemer,E. P. KlierJ. L. FisherF.C.WagnerJ.O.NlackM. A.BishopSelmaKrauseMina MoessenP.VonadaH. Colyer

TechnicalRepresentativeInvestigatorInvestigatorInvestigatorInvestigatorResearchAssistaz%DraftingTechnicalLaborTechnicalLaborTechnicalLabcr

TII MATERIALS

1$9Detailedinformationon the eteelsusedwill be foundi.nearlierreports .

Chemicalanalysesare containedin Table1,

Threesectioneof 72-inchwide plateewhich had beenbrokenby the center

9notchtensile testin the coureeof previousinvestigationsme shownby

Figures35, 41 and .+8. Specimensfrom theseplateswere usedfor hardness

contoursurveys.

IV METHODOF TEST—-—.

A-Hardness—-,——

StandardLH (longitudinalspecimenswith the notchperpendicularto tl?e

plate surface)V-notchCharpybarswere brokenat temperaturesselectedto

coverthe entiretransitionzone. Temperatures,energiesand fractwe

appearancesare listed

Afterfracturing

-5-

in TableII.

the barswere nickelplatedto preservethe fracture

surfaceand were sectionedon the centerplaneperpendicularto the notch.

The half specimenswere nextmountedin a plasticwhtihset,at room temperature,

and were polished. Finally,a regularpatternof indentationswas’made on the

polishedsurfaceusinga Vickersdiamondand a 1000 g. loadon a Tukonhard-

ness testingmachine. Preliminarytestshad shownthattheseconditionsof

testwouldeliminateany effectsof @e,inorientation,but wouldprecludean

appronch to the fracturecloserthan0.01 inohes. This degreeof sensitivity

is adequateto revealmacroetopicdetailof the straingradient. Preparation

qnd testingof specimensfrom the largefracturedplateswa~ done,in like

manner.

Thesehardnesedatawere plottedon a scaledlikeness

and linestonnectingpointsof equalhardnesswere drawn.

of the speciinens

Thie processgave

a hardnesscontourmap md, consequently,an approximatestraincOntO~ maP.

In“orderto permitrepieeentationof the n~rdness“gradientin a more easily

visualizedmanner,the linearhardnessgradientsat the base of the notchand

at a pointmidwaythroughthe fractufe,were determinedand plotted.

ThreeCharpyspecimensof steelC were testedin the conventionalmanner

exceptthat the hammer’was not raisedto its full height,ht rather“toa

heightinsufficientto causecompletefractureof the bars. The hammerre-

boundedafterstrikingthe bar, but was arrestedbeforeit couldstrikethe.,. . ,.

bar a eecond.time, Cond5.tionsof testwere ae follows:

,,.,;

,’

,.

-6-

Test,A

Temperature‘F 212

K, E. of Hammer 13

BendAnglo

Crack

These specimens

B-Metallom?aDhv

9°

None

were eectioned,mounted,

Test B’

212

34

22°

VeryShallow

polishedand teeted as

TestC

212

54

38°

113 throughBar

describedabove.

Ilicrosectionsweremade of all specimens,and photomicrographsof the impact

specimenewere takenat the

Microstructumlevidenceof

was observedand recorded.

notch,midwaythroughthe bar and at the back side.

Neunmnr,Bands~ strainlinesand graindeformation

C-X-RayAnaIvsis-——

Specimensof steelO

face and ductile’fraoture

representingthe virginmetal,a brittlefracturesur-

eurfaceswere used. In orderto insurea cleanand

completebreakat tke fracturestifrices,the Schrwdttypebar was ueed and wae

biokenby the elow’bend technique..4Sachs type camerawith both cassetteand,,, .

specimenstaticnuy was ‘used.Exposureswere madewith K 0< radiation.

V - RESULTSAND DISCUSSION

A-X -RqvTests

The X-raydata are presentedin F igure2. Pattern(a) is for the virgin

metal. Tbe pointof interestis the resolveddoubletleadingto two lineson

the pattern(<~ and< ~). Thoselineeare typicaland are used as reference

lines. Patterns(b),(c), (d),and (e)were tn.kenon duc”~ilefract~lres~f aces.

From the lack

existsat the

of resolutionof the doubletit may be etatedthatextensivestrain

fracturesurface. Fincllyin pmttern(f),takenOn a brittle

fracturesurface,

the strain}if it

the doubletis

existsfor the

-’7-

resolvsdas in pattsrn(a). This meansthat..

brittlefra.ctu.re,was insufficientto be picked

Up by.thisX-my diffrm.tiontechnique.Sinceit is estimatedtho.tthe X-ray

procedureused will reveala straingradientof .0001inchthicknees,it ie

indicatedthat a straingradient,if it existsadjscentto the brittlefrr.cture

surface,must be no thickertkn 0.0001inch. A gra.dient of this exteutcould,

underno circwsstanccw,leadto high energyabsorptionin its development.From

thisit followsthatfor practicalpurposes~ the straingradientconstruction

presentedin Figurelb conformswitlitileexperimentalresults.

Additionalinformationin termsof metnll.ographicdatapertainto th;.spoint.

Thus,in Figure 3) the frocturesurface is typicalof a duchilefailure. The

metallcgraphicstructureshowsa highlytornand deformedzonee.tthe fracture

edge. This zoneo.ppearsto be of the orderof .01 inch thick. This region

rapidlypassesintoa zoneof much lowerplaSticstrain~rIzom, howeverj in

whichplasticstrainis stillappreciable,cm indicatedby the distortedgrains.

-In Figure4 the fracturepresentedis to.brittlefracture. Thereis nO evi.donce”

of plasticstrainaccompanyingthis frc.cture.The metellographicdata~ there-

fore,me in full agreementwith the X-raydata,for the considerationof the

‘ideal)!brittleand ductiletypoeof failure. Add;.tionaldata concerningthe’

metallographyof mlmt mightbe consideredintermediatetypesof failureare

presentedin subsequentsections.

The X-rciyand metallogra.phicdata

aceeptanoe.ofthe straingradienttype

the straingradienttypepresentedin

tionsat the fracturesurface.

whichhc.ve“beenprese~itedargueagainst

prbsentedin Figurela. By elimination

Figurelb appearsto destribethe condi-

-8-

B4H~~ne~~ Gradients,0f B~OkenCharpY Barg

Hardnessgradientdataare presentedin Figures5 to 8 .snd12 to 34, in

the formsof contourmaps and lineargradientsat the notchand at the ceuter

of the Charpyspecimens.Theabdatawill be consideredin groupsbadedon sim-

ilarityof enerf$absorptionand posi“tionin’the iraneitionzone.

Group1 - Low EnergyAbsorption,(<7 ft. Ibs.) Figures5,6,7,and 8. The

,speoimenof steelC ( Figures5 and 6) with an energyabsorptionof 3 ft. 10S.

would be considered‘)100~granular!tby conventionalueage. The hardnessc~iltO~

indicatesvery slightetrainsat the notchand underthe tup, but the crack

itselfwas not accompaniedby strainwhichwas discernibleby the hardnessmeas-

uringtechniqueused. Thesesameremarkeapplyto the specimenof eteelE

(Figures7“and 8), with the exceptionsthatthie fracture.showd slightlymore

sheartinderthe tup and greaterstrainat this location. Photomicrographsof

this specimen( Figures9,‘10,..and I.1)are~in agreementwith the hardnesadata.

It is,evidehtthat the crackin.thisspecimenwas compl..etedbeforethe major

~part of the straining”occurred. Thisfollowsfrom the fact that it wouldnot be

@e&ible to’sti%ifi‘an.untrackedspecimenat the tup withoutcaueinga ccurespond-

ing &trainat the motch. Hence,most of “theetrain at the t~ must have reeulted

from bendingof the”epecimenaf$er completionof the brittleportionof the crack*

Group”2- MediumLow”EnergyAbsorption(10-16ft. lbs.) Figtime.512-17..The

hardnesscontoursof khisgroupare similarto thossof group1 with the excep-

tion the strainat the notchand the tup is greater,and consequentlythe length

of the brittlecrackthroughunstraitwdmetalis shorter, The same.analysisof

strainingpriorto; and after,formationof the brittlecrackapplies. Notice

thatthe brittleportionof the crackis stillnot accompanied..by a macroscopic

straingradient.

-9-

Group 3 - MediumHi?hEnergyAbso@.ion.(27.5- 54.0ft. lbs.) Figures

18-25. The hardnesscontiov.rsof this groupare similarto thoseof groups1

and 2 with the cxoeptio~lsthat the zofleeof strainat the notchand th6 tup

are stillgreaterand are extendedsuffici.ently,at 45° to the specimenaxis,

to contacteachotherbeneaththe crack.(e.g.Figurelb’). Theresti~~exist

regionsof brittlefracture,however,showingn,omacroscopicstraingradient,

with the poesibleexceptionsof curvesE in Figures16 and 23. Theseslight

etraingradientslikelyresultfrom the appreciablebondingwhichoccurredprior

to the formationof the crackratherthanfrom a mechanismaccompqningthe

brittlecrack. ‘Notethe markedrise of the B curves,whichobviouslyreflects

the extensionof the strainedzonesat the notchand tup.

Group4 - HighEnergyAbsorption(>’70ft. ibs.) Figures26-31. These

fractureswere fullyductiluonos. The hardnesscontoursshowthat the region

of no strainat the centerof the barshas vanished. However,tineintensityof

the strainat the centm of the bars ie stillmuch lowerthem it is near the,’

notchand tup.

Thesestraingradientstudiesof brokenChe.rpybarslead to threeobserva-

tions:

a- A ductilecrackin a Charpybar is not accompaniedby a distinctfva

and uniformmacrostopicstraingradient,for if it werejtheA and B curves of

the totallyductilefractureswouldbe alike.

b - A brittlecrackin a Charpybar can be propagated

free,or slightlystrainedmaterial~ withoutimpositionof

gradient.

througheitherstrain-”

0. macrostopicstrain

c - The macrosco~picstraingradientsof a brokenCharpybar largelyreflects

the strainresultingfrom bendingactionsratherthanany crackpropagation

phenomena.

.

-1o-

,C-Hardness”Contotisof BentCharm Bars

The hardnesscontoursof the threeCharpyb~rswhichwere struckby a

Che.rpyhcmunorpos.+essingenergyinsufficientto causecompletefractureare

shown in Figures32, 33, and sl~,

Figure32 illustrates‘the‘distributionof the etrainpriorto crackforma-

tionfor conditionsof testunderwhichductilefracturewouldoccurif energy

sufficicntti effect’fracturewere availnble. Noticethe steepstraingradient

renderthe “notchand, to a les’ecr degree,at the tup,and the strainfreemetcl

near‘tothe neutralaxis.

Figure33 cliff ers fromFigure3’2in degreeonlywith the exceptionthata

shallowductilecrackextendsfrom the notch.

In FigureZ; the betidingactionhas proceededsufficientlyto causestrain

at the centerof the bar,and the ductilecrackis extendedfurtherintothe

materialstrainedby”bending. The straindistributionand intensityresemble

thoseof Figure2S~ whichrepresentsthe snmosteeltestedat the same temperat-

ure but with energywhichwas sufficitmtto causetotalfracture.

,,

D - HardnessGrc.dicntsin LargeFracturedPlates.—.

It is evident,from resultspresmted ‘above,thattilestraingradientsin

brokenCharpybars are largdlyreflectionsof the amountof bendingpriorand

subsequentto the formationof thd crack. Consequently,it was realizedearly

in the couzseof this investigationthatfractureswhichhad occurredundsrthe

actionof tensileforcesonly should.be includedin the straingradientstudies.

For thisreason,specimensfrom T2-i.nchwide plates~ whichhad been fractured

in the centernotch

PlateC-3 will

tensiletest,

be considered

were examined.

first. From the chevronmarks (Figure35)

-11-

it is evidentth?.tthisplatefailedwith a !Ibrittlet!crackterminatingat the

notch. Figure36 indicatesorient[!.tionsend locstionsof the hardnesssurvey

specimens.Figuree37-40show the hardnesscentaurs,fromwhichtwo significe.nt

o’csorvationscan be made:

(1) Some portionsof this s~ittl,esCr:,Ckare not accompaniedby o dis-

cerniblemacroscopicstraingradient,i.e.~ the brisehardnessof the plateex-

tendsunchangedto the cracksurface.

(2)Some portionsof this ‘tbrittl.etlcrackire accompaniedby fairlysteep

and shallowstraingradient+,whichcan occurin the centerof the pi.fite(e.g.

Figure351)but lwhichare especiallymarkedat the plateemface (e.g.Figure40).

Theeoobservedfactscompelthe conclusionthat thoseLocationson the

crackwhich are urmccompaniedby a etraingradientwere cracksindeedpriorto

the separationof the materialat thoselocationson the cre.ckwhich are accom-

paniedby a straingradient. The most obviousof the possibleexplanationsfor

this markedvariationin the straingradientsat di.ffercntlocationson the

same IIbrittlellcrackis that the reducedconstraintresultir,gfrom the growth

of the crackallowedappreciableplasticstrs.inat the locationswhichwere

lastto separate. But in amy event?thesespecimensindicatethatc.crack,

whichwouldbe classifiedas !Jbrittlo!]by conventionalcriteria,may or may not

be accompaniedby a macrostopicstraingradient.

Plate22-lKie shownin lin~drawingby Figure42. From its photograph,

Figure41$ it is evidentthat the crackwae !~ductile!ifrom the notchto the

locationof specimenNo. 4$ thence‘}brittle!!to the plcteedge. With the addi-

tionalobservationthatthe ductileportionsof this crackshow the expected

straingradient,(FQurcs 43-47)the resmrkspertainingto platepreviously

discussedapply. ,. ,,

,.

~.

Plate N-1-A is shownin line

Figure48, it is evidentthatthe

-12-

drawingby Figure48. From its photograph,

crackoriginatedat the notchnnd extended

in the 1!ductiletlmode for approximately1/2 inchbeforethangingto the !lbrittlell

mode. It shouldbe noted9that thisplatewas unusualin that it absorbed

approximately1/3 of the maximumenergyobservedfor a totally‘1ductilet!speci-

men of the s?mematerial. The straingradientsof thosespecimensnear the

notch,Figures50, 51, and 52, closelyresemblefindingsfrOm the PrevioustwO

plates. Figure 53, however,which represents‘Ibrittle!!behavior,differs

markedlyfrom the otherSbrittlo!!contoursin its demonstrationof definiteand

uniformlydevelopodmacrostopicstraingradient. In thisrespect,Figure53 is

not unlikepreviouslydiscussedcontourmopswhich represent‘tductile!’behavior

(cf.Figure43), with the exceptionthat the gradientslopedoes not sharply

incrcceein steopnessnear to the fracture. It is suggeetedthat the “brittle

gradient’]of Figure53 mightbe relatedto the unusuo.llyhigh energy?.bscrption,

in th~t it couldbe reflectinggeneralstrainingin a zonebetweenthe notch,.

and the plateedge rather“thann strainincidentc.1to, or necessaryfor, propa-

gationof the crack,

E - liietdlograph~

Results.ofmital.lographicexaminationare“presentedin Tables2 and 3,

and in Figures3, 9 to llj and 54 to 59.

.Inthe tables,frccturetypesaro listedas ‘tbrittle,‘t‘tductile,” and

‘tbrittle-ductile,’)The lastmentioneddesignationindicatesuncertaintyas to

the typeof behavior. It shouldbe emphasizedthat theseclassificationare

based.onmetallo’grmphicdata only,

Figures9, 10, and 11, respectively,

sdctionswhich intersectthe crackat the

illustratethe microstructurosof

baseof thenotch,midwaythroughthe

1

-13-

bar and at the backof the bar,of a !Jbrittle!!specimen($teel.E, 36°E). The

straingradientsof thisspecimenare representedby Figureo7 and 8. It can

be seenthat the hardnessdata and m.icrostructui%sme in rwyeenent,with the

exceptionthatmicrostruct,lme(Figure9) showsevidenceof considerableplastic

strainin a very restrictedzoneat the base of the notch,whiohstrainis not

evidentin the hardneeaconto~ (Figure7). This ~!dis.c.greomentt!unqueetionc.bl.y

reflectsthe greatersensitivityof metallographicexamination,as comparedwith

the hardnesstests,and stronglysuggeststhat the strningradientsat ductile

fractmes are actunllymuch steeperand reachmuch higherstrqinvaluesvery,, ,,

necr (< 0.01”)to the cracksurfacethan is indicatedby the M.rdneescontours.

Figure10 clearlydemonstratesthe total.lack of any metnl.lographicme.nifesta-

tionsof strainat s.cleancleavageseparation.,.

Figures5/,and 55, respectivelyillustratedeformationtwinsand strain

lines,not necessrn’ilytypical,ocmrring in brokenCharpyb~rs.

Figure56 representsthe locationin plate,22-l-Kat whichthe cre,clr,,

chnngodfrom the ‘!ductil.elrto thG ‘Ibrittle!tmode. iiotetho typicalevidence,,, .,,-.. .,,..,’

of an appreciablestraingradientadjocentto the ductilepart and the clean,

etrain-freecleavageadjscentto the brittlepartof the crack.

Figure57 representsa !Ibrittlel)locationof the cremkin plate22-1-K.

The previouslymentionedcharacteristicsof Q cleavagefracturdare illustrated.

Note also the typicaltrans-crystallinepath,which is interruptedby a very

shortinter-crystallineseparationat the pecrlitegrainnear crackmidpoint.

Figure58 illustratesthe abovementionedcharacteristicof a cleavage

crackand in addition,rcve:llsinterestingbehaviorof the crackin the ferritd

grainnear its midpoint. Noticehow the crcckbranchwas rnuwatedwithinthe

ferrite.grain.

—

-14-

“Figure59 representsa cleavagecrack. Of interest.isthe deformation

of the ferritef~agmen@ whichevidentlysuf~eredConsiderablestrain,

althoughttiecraokcausedno discerniblestrainin the main body of the ferrite

or pearli$egraine. ,,

,,

VI CONCLUSIONS,, ,,..,,

1- ‘“”;The etraingradienta; some’~ocationson any Sbrittlell&ra”ck,if it

!,~,’;. ,..,. existsindeed,ie so restricted’aS to depth’that it is not detecthble”by

,,X-rayor metallographictests.

:<

,, ; ,; ,,.., ,.:

2 -“’ The straingradientsat somelocationson most’‘brittle’$crackbis,.;,,; .;

not characteristicallydifferentfrom the straingradients0$”a“1$diet’~lei!,. . ,, ,,,,,1,,’‘.+i! ., >. i,:..,.:

crack.

3- Fractureswhichwouldbe classifiedas “b~itt,le”by convehtf.onalusage,, ,’ ,. .’,

e.g.,by,CYOSSappearance,generallydisplay”’both Of”the abovetwo typesof*;:r ‘,,:.:~.!. .,.1 : .:.,:

straingradients.,: ,!.’.”

4- ““ Figure1(b) schematicallyrepresentsthe differencebetweensepara-,,:~~

tionby shearand separationby cleavagewithrespectto etraingradients,,,, . ., .,,,, ,,, .

exceptthatthe cross-hatchedareashouldbe isiieaetiably””amal~.,,.,,...,;.,..:.:

,..’..: !.”

,. (

,., .

,,, ...

,,.

-15-

REFERENCES ““’”“

1.

2.

3*

l+.

5.

6.

7.

8.

ProgressReport- ResearchProjectSR-96,SerialNo. SSC-9,Contract

NObs-31217datedMarch19, 1947.

F. Sauerwaldand H. Yieland: Z, Metallk.~ (1925)‘p.358/63and 392/9;

St. und Eisen46 (1926)p. 5.46.

M. Moser:KruppesheMonatsh.2 (1921)p. 225/40. St. und EisenQ (1922)

p. 90/7;Z. V. D. 1. ~ (1922)p, 43.

R. Hinzmann: Dissertation.Techn.Hochsch.Berlin,1925.

F. Sch~e: Materialpr~. Anst. a,d. Eidg.Techn.HochschuleZ}rich1913,

Vol.10a.p. 1/16;St. und Eisen~ (1911+)p. 1266,

F. Sch’~eand E. Brunner: Intern.Verb.KopenhagenerKongress1909 III,2,p

1/6;St. und Eisen~ (1909)p. 1453.

F. Fettweiss: Archivf[r Eisenh\ttenwesenApril 1929,Vol.10, p. 660.

C. W, MacGregorand J, C. Fishert Jrnl...AppliedMechanicsQ ~flarch(1944)

p. A28/A34.

9. FinalReport- ResearchProjectSR-92}SerialNo.

‘datedJanuary1947.

10. FinalReport- ResearchProjectSR-93,SerialNo.

datedJune 1947.

SSS-8,Contractl!Obs-31.222,

SSC-1.0,Contractl!Obs-31224,

11. C, S. Barrett: Structureof Metalep. 305. LlcGraw-HillBook Company,

New York (1943).

-16 - L

. .

TABLE I. . .

ChemicalCompositionsof the Steels

,.., .’ ””,

m THERMALTR.EATMEii’f~ % &“”’m.,... ,,,,:.,: .,.

A As-rolled 0.26 0.50. .,0.02:

c As-rolled o.2~; .! 0..4$, :.:Q,Q2.:“

Dr As-rolled 0.22 0.55 0.,16,,...,,.’

E As-rolled 0.20 0.33 0.15

c-3-A Same as C above,,.,,

22-’lK Same as Ilrabove

N-l-A As-rolled.,

0.17 0.53 3“39

TAB:EII

Spec.

KRI-5KRA-1KRG-4KFrF-6

I-28I-51-21-19

31W-3RRB-1RRC-3R31-1

Steel

DrDrJrDr

Gccc

~EEE

TestTerm,,‘F

-40-91852

-30254598

22477

100

FracturePhenomenain CharpyV-l~otchTest Ears ‘

FractureTypeand Lo6ation ‘ DeformationStiuctureand Location

E.A~l# “ ‘Notch Center ~~“ Back Iiotch Center Back. .

—- — —.-..

m ‘“ d, “. B B-D lT.13.3 17=3. s=I1.2’?.5 ~z B D S.L04 N.B. S.L.46.5 D B D S.L. y.2.

80.5 DS.L..

D D S.L. ~-.,.A. S.L.

B B B N.ti. ~,;:BO N.13.3; D B D S.L. “~~.B.(2) S.LC :

D 3 D S.L. ““’B.,,. S.L. tz D B-D D s.Lo S.L., S,L. F<

,B B B-D ~:..B. 1~.B. “i~.B. & ‘S.L.

1: B-D B B S&. ~:e~. N<.B,5L B B-J B-D s.I,. N.B. s.,L.70 D D

1 - B = Brittle2 - D :=Ductile

3- N.B.= NeumannBands4 - S.L. z StrainLines

.

I) S.L. S.L. S*L.

(deformationtwins) ::...

.. .. .

TABLE 111—.

FractureF%enornenain LargePlateSpecimens

~m(lfNIA(2)rIA(3)NIA(4)

I C:3(1)C-3(Z)c-3.(3)C-3(4)

22-lK(l)

!

22-M(2)22-lK(3)22-lK(4)22-IK(5)

101to

104

FractureTypa& Location6 DeformationStructure& Location.1. 2. 3 1. 2.- 3.

~1 D D.,D D D ~L.3 CL, ~L .. ..

D!2. B

D — — —o B — — —

B B B-D S.il.’—B B B }!.B.fi S.L.(r) N.B.—B B B-D ROB. N.BO & S.L.(r)~.B B B a.L. N.E. S.L.

D DD B-DB-D BB B

DDB-DBB

~. ~ S.L.~..”.,’=“.L. S.L.S.L. 4S.L.(r) Cars— —

1 -D= Ductile2 -B= Brittle3 - S.L. = StrainLines4.- SOL...= StrainL@es highlyrestricted5.- N.B. = Neumannbands (deformationtwins6 - Specimennumberand locationmay be takenfrom appropriate~

line drawing(figures35,42, ad 49). Locations 1, 2, and3 are left,centerand rightportionsof.“transversespecimenslookingin directionof crackpropagation;they denoteleft,centerand right portionsof longitudinalspecimenswith thenotchto the left.

S.L.S.L.—

1:-J0)

I

FIG. I IDEALIZED FORMS OF STRAIN GRADIENT

1_______——‘ii’\\\\ \!%\ ‘\\\ \ .\\\ \\ -.—.>. —————’-— ——————-

BASE H1

(b)

‘\ ---_____ __

\\

( “%\&\\\?.. ::_’ ______

~\

iD–N Essi

\ I

l-—————x—————L------DISTANCE FROM CRACK DISTANCE FROM CRACK

20

Fig. 2 - X-ray Patterns Steel A

21

Fig. 3 The Fracture Midwey Through the Specimen Steel Dr.Thi6 18 a fully ductile specimen. (Cf. Fig. 26 C?27)Nital Etch x 600.

.22

Fig. 4 - The Fracture Midway Through the Spec~men Steel C.This is a fully brittle specimen. (Cf. Fig. 5 & 6)Nital Etch x 600.

FIG. S

DPH CONTOURS STEEL C

v- NoTcH SpEaktEN

A B TESTED AT -22°F

ENERGY ABSORPTION 3 FT.-LBS.

,/15~

/20+

/20 *

0.0 0.3 0.4

WIDTH-INCHES

24

22a

20C

18Ca<~

: 16C

Tr&n

I4C

12C

I 0(

4FIG. 6

HARDNESS GRADl ENT STEEL C

V- NOTCH SPECIMEN

TESTED AT ’22 ‘F -

ENERGY ABSORPTION 3 FT -LB

CURVE A

●

0.1

—

0.2

DEPTH BELOW FRACTURE - INCHES

25

wJmw1-(J3

k

w

m .—-..>— .—.

<

o‘+

obT--

26

220

200

180

nuo-J~ 160*Tza~ 140

120

I 00

FIG. 8

+ARDNESS GRADIENT STEEL E

V- NOTCH SPECIMEN _

TESTED AT 36 *F

ENERGY ABSORPTION 7 FT. - LBS.

\CURVE B .

0. I 0.2

DEPTH BELOW FRACTURE - INCHES

27

Fig.

‘,

9- The Character of the Frecture at the Base of theNotch Steel E, (Cf. Fig. 7 & 8). Nital Etch X 600.

Fig, 10 - The Fracture Miduay Through the !3peclmen Steel E.(Cf. Fig. 7 & 8). Nital Etch x 600.

29 “

Fig. 11 - The Fracture at the back of the Specimen Steel E.(Of. Fig. 7&8). Nital Etch x600.

FIG. [ 2

DPH CONTOURS STEEL or

V-NOTCH SPECIMEN

TESTED AT -39 OF

‘)0

ENERGY ABSORPTION I’D FT.-LBS.

17 A-, *A I I - \

1, II0, I 0,2

\

I0.3

WIDTH-INCHES

31

E00

\\ #

120

100

DEPTF

FIG. [3

HARDNESS GRADIENT STEEL D r

V-NOTCH SPECI MEN _.

TESTED AT ’39 “F

ENERGY ABSORPTION 10 FT. -LBS.

CURVE A I I

2+5---F0.1 0-2

BELOW FRACTURE - INCHES

FIG. I 4

DPH cONTOURS STEEL C

V-NOTCH 9PECI MEN

TESTED AT 50 “F

A B ENERGY ABSORPTION 13 FT. -LBS.

,176 .132,S[60 1s0

./s5 )=130 “/.26.5

r

‘Y

/90 ,/44,5 .1/4 170;llo

I

)

(

1,/90 *117

~~

I I/30? .1 3

>

.115,5@

,133.5

k

/30 / o

\fn ‘7°

~ 30 >; <y

!/%3.5

!/25

I

/ / [’2”5I

o.I 0,2

WIDTH-INCHES

I

I0.3

uto

33

240FIG. t 5

HARDNESS GRADlENT STEEL C

220 ~V ‘NOTCH SPECIMEN

TESTED AT 500 F

ENERGY ABSORPTION 13 FT -LBS.

200

n

~ 180

0<iX 160&o CURVE A

I40

\‘Q

120 ~>L .g’

o\CURvE 8

I 000.1 0.2

DEPTH BELOW FRACTURE - INCH ES

u-i

wmJ

(nwsv

*5-.01

s1-0

3

<

35

220

200

180

160

140

120

100

1

FIG. 17

IARDNESS GRADIENT STEEL E

V-NOTCH SPECIMEN –

TESTED AT 75 “F

:NERGY ABSORPTION 16 FT-LB S.

CURVE A

0.1 0.2

DEPTH BELOW FRACTURE - INCHES

FIG. 18

DPH CONTOURS STEEL Dr

WIDTH -lNCHEs

37

FIG. 19

HARDNESS GRADlENT STEEL DI

V-NOTCH SPECI MEN

TESTED AT 16 ‘F

ENERGY ABSORPTION 275 FT.- LBS

9

0

/

./z

/00

/ 0“-c-~” CUR VE B

0-

0.1 0.2

DEPTH BELOW FRACTURE -1 NCH ES

38

39

k-lFIG. 21

@ HARDNESS GRADlENT STEEL Dr

220V-NOTCH SPECIMEN

TESTED AT 64*F

ENERGY ABSORPTION 46.5 FT-LBS

180 ,

160

140 -

00~%= >0

0

120

I 00

b

CURVE A

● *

/“ \“

0/ ‘“*/ CURVE B

//

&

I I

0.1 0.2

DEPTH BELOW FRACTURE - INCHES

FIG. 22

DPH CONTOURS STEEL C

V-NOTCH SPECI MEN

A BTESTED AT I I 3 ‘F

ENERGY ABSORPTION 52 FT.-LBS.

WI DTH-lNCHEs

240

220

200

n

~ 180J

ox

i160

:n

14C

I 2C

10(

●

k●

9

FIG. 23

HARDNESS GRADIENT STEEL C

V -NOTCH SPECIMEN

TESTED AT I13°F

ENERGY ABSORPTION 52 FT.-LBS.

CURVE A

\

●

0°

/ CURVE B/

?’ ~

o. I 0.2

DEPTH BELOW FRACTURE - INCHES

FIG. 24

D PH CONTOUR S STEEL E

V-NOTCH SPECIMEN

TESTED AT 170 “F

~ B ENERGY ABSORPTION 54 FT.-LBS.

K/+o-

,(0>~w?fwqy

I I I I0.I 0!2 0.3

WIDTH-INCHES

43

FIG. 25

HARDNESS GRADl ENT sTEEL E

v -NOTCH SPECIMEN -

TESTED AT 170 ‘F

ENERGY ABSORPTION 54 FT. -I-B:-.. —..

\

●

●

m 1

/ “ CURVE B ‘\0/A ●

M’ 0

0.1 0.2

DEPTH BELOW FRACTURE -INCHES

,.’ L+

45

220<

200 b

CURVE A●

./A\

4I 80 K

n

q l!” C:RVE\oh

~ 160 \“

ix0.n

140FIG. 27

HARDNESS GRADlENT STEEL Df

12 0V-NOTCH SPECIMEN

TESTED AT 126 ‘F

ENERGY ABSORPTION 80.5 FT-LB s.

I100

I

0.1 0.2

DEPTH BELOW FRACTURE - INCHES

Mi

Uim

aml

dG

L

zIll

‘T––=––

-:’

—

V)w

N-.c)

—

-6

240FIG. 29

HARDNESS GRADlENT STEEL C

V-NOTCH SPECI MEN -220

TESTED AT 212 “F

● ENE;GY ABSORPTION 80 FT. - LBS.

200●

CURVE A

n●

●

u o

q 180/

/ ‘o

0 0 oOgSt

o CURVE B--.+ _ .- /~

i 0

X 16 0mn

140

120

loo~ Io. I 0.2

DEPTH BELOW FRACTURE -INCHES

49

240FIG. 31

HARDNESS GRADIENT STEEL E●

220 V-NOTCH SPECIMEN –

TESTED AT 212 “F

ENERGY ABSORPTION 70 FT-LBS

200CURVE A

og 180

0~-.CURVE B

o 0x

i —~~ 160 .s

● O’\

a●

●

140

120

1000. I 0.2

DEPTH BELOW FRACTURE - INCHES

1130- 0

0 \,,

!30- ! 120-

/

120 +/’ 7

~)@ O1.l.oW<p:i.LL,

‘$2 jJ~~;-

a

120-.J

u!0

D

!20- 120-

! 20 120 ,*

10 IM 1s0

([

o ‘7” ‘e” ‘ ’40 ’30Iao

I 70

0!0SCALE IN INCJWS

& CA

51

-a

0-(N‘N

II

Ic-lco

0-0

52

/‘\ ,

/’” ..\-’ . ......_.._J\~‘) ~-–--””“-”----- “–” ““””\~_

\ ,’”(“-”””””5”””\ \

53

&.,4

!+

PLATE C-3

.0..,,0. OF SP, clklc.s

__ c: ~___—.– .—. ––.. .- ,.,., ”., ——- .— — -

L---. --—

.0., A ,.,’ ,,2.,

Fig.36 - Line Drawingof PlateC-3.

.,, . . CONTOURS

I KG. LOAD

,.,,, c ,*PEC .0

Fig.37 - HardnessContours- SpeciimnNo. 1, PlateG3.

55

D P H ,..,0”.s

KG LOAD

,,

T:,..

,6. , ,,...0-

!,0,,,. ‘m’

%%. %

,6, ,,,. , ,,,.

,6. $ !60 ,,0.E4.

o ‘“”,,0.

Fig.38- HardnessContoursSpecimenNo. 2, PlateC-3

o P. CONTOURS

, .’ mm

,,.,, .3

,,,.. .0.3

;. 0’6 o.i& 02

,CALL .1. l...~,

Fig.39 - HardnessContoureSpecimenNo. 3, PlateC-3

56

., P CONTOURS

. . LOA,

., AT, .3sm. .04

Fig./+0- HardnessContoursSpecimenNo. 4, PlateC-3

58

-— c , —WCTILC+ --- - a.’,,,, FRACTURE ‘—

r’y’-- ‘w X —.0 % —-

Fig. L@ -

o P,H. CJXTO”P5, w. mm

PM,, 22-,.

.,,, WI

Fig. Id - HardnessContoursSpecimenNo. 1, Plate22-lK.

59

Fig.l+k- HardnessContoursSpecimenNo. 2, Plate22-lK.

Fig. 45 - Hardness ContoursSpecimenNo.3, Plate22-lK.

60

0.,?. Cn.m”.,

( KG mmKATE ,2.,.

s,,. m.

Fig . k6 - Hardnesm GontOuraSpecimenHo. l+,Plate22-lK.

OP. .0.,0 ”.,

, .’. ,0..

,,.,. 22,.

wig. 1+7- Herdness ContoursspecimenNo. 5, Plate22-lK.

61

62

m,,, .! ALOCATION OF SPECIMENS

k. —..,. ...+.. --—- FR,’T..E —— .—.

p. ..,%... .L

I

‘~..—.%-~,~? IJ~i m u “f

NOT. : A ,,EC. ,,3,4,

, ,,s., ,

I

II

—3. 7[, ———..

{

c H ,RACT”61 IS OF WCTIU NATURE FOR APPROXIMATELY @,,,ROu cur. WANCE Calrm.c.

Fig. L9 - Line Drawingof PlateN-1-A.

0? H CONTOURSKG m.,

m.,, N,.

0’0 0:2 0:4 & ..i5CALE !N INCHES

Fig. 50 - HardnessContoursSpecimenNo. 1, PlateN-l-A

63

w“ CONTOURS

, . . LOAD

Fig. 51 - HardnessContoursSpecimenNo. 2, Plate N-1-A

, ,. ‘0.,0.,,

. . LOA,

,,.,, ., A

s-c .0 3

Fig. 52 - HardnessContoursSpecimenNo. 3, PlateN-l-A

,,..

Fig. 53 - HardnessCOntOUrSSpecimenNO. 4, Pkte N-1-A

65

Fig: 54 - Deformation TWiIIB in Steel C. IiitalEtch x 600.

66

Fi~, 55 - Strain Lines in Steel Dr. Nital Etch x 600.

67

Fig. 56 - The Fracture for Specimen No. 4 Plate 22-lK showing DeformationTwine and Transition from Brittle to Ductile Failure. IUtal Etchx 500

Fig. 57 - The Fracture for Specimen No. 5 Plate 2>1K ehowing Brittle Crack%of inter-and intra-granular types. Nital Etch x 500

69

Fig. 58 - Another Region for SPeoimens No. 5 plate 2~lK.Nital Etch x 500

70

Fig. 59 - Character of the Fracture in Specimen No. 4Plate 22-M. Nitel Etch x 500.