SAE8000 series fatigue index file

SAE8xxx Steel fatigue file index :

Created: Aug19-2009 Updates: June2016 Jul,Sep,Oct2018 Jan2019

Note! : The files in this directory are offered by the AISI Bar Fatigue committee members as a set of example files for the construction of web based material fatigue property databases. They are meant for information and research use only, not for design.

AISI Bar Fatigue Project 4-Point Bending Specimen Description:
- 4-Point bending fixture (picture)
- 4-Point bending specimen (picture)
- Geometry and Kt of 4pt Bending specimens (graph)
- Kt of 4-Point bending specimens (text file)
- Bending specimen geometry (text file)
SAE8615 series
- Shallow vs Deep Case Study:
  Objective: Use 8615 (a low carbon carburizing steel) to determine
  the effect of Low Hardness Core and Shallow vs Deep Case depths.
  Note that IGO also differs. All samples in this series from same heat of steel.
  (wt.% Sulfur= 0.035)
- SAE8615 Simulated Core __ | __ Fitted AISI Iter. 155
  Const.Ampl. Axial Quench+Temper HRc=20
  PartialTensile Tensile+Cyclic Met.Report FatigueReport
- SAE8615 Simulated Core
  Const.Ampl. 4-Point Bending, Quench+Temper HRc=30 AISI Iter. 156
  Met.Report FatigueReport
- Compare Core only: Axial vs Bending (graph)
- Shallow:
  - Hardness and Microstructure
    - MicroStruc.Components + Residual Stress Axial Composite AISI Iter. 157
    - Hardness profile Iter 159/160 (graph)
    - Surf. micro. (100X)
    - Surf.micro (500X)
    - Surf.micro. for IGO (1000X)
    - Mid-radius micro (500X)
    - Core (500X)
  - SAE8615 Carb. Case+Core Const.Ampl. Axial (Carburized in atmosphere ) AISI Iter. 157
  - SAE8615 Carb. Case+Core PeriodicOverloadAxial (Carburized in atmosphere ) AISI Iter. 158
    MicroCoreLowX MicroCoreHighX MicroCaseLowX MicroCaseHighX Met.Report
    Tensile Tensile+Cyclic FatigueReport
    (The shape of tensile curves suggest that the Case fractures
    first and then the core continues to deform )
  - SAE8615 Carb. Case+Core Const.Ampl. 4-Point Bending Specimens AISI Iter. 159
    SAE8615 Carb. Case+Core Periodic Overloaded 4-Point Bending Specimens AISI Iter. 160
    Met.Report FatigueReport(159/160
- Deep:
  - Hardness and Microstructure
    - MicroStruc.Components + Residual Stress Axial Composite AISI Iter. 161
    - Hardness profile Iter 163+164 (graph)
  - SAE8615+DeepCarb.Case+Core Const.Ampl.(CA) Axial Specimens AISI Iter. 161
  - SAE8615+DeepCarb.Case+Core CA + Periodic Overload Axial Specimens AISI Iter. 162
    - Final Reports Iter. 161+162 pdf MicroCase MicroCore Met.Report
      Note: Internal crack initiation observed (fisheye) in some specimens.
      Fracture surface pictures in Appendix C.
    - Compare ConstAmpl vs POL Str-2Nf (graph)
    - Tensile Stress-Strain (graph)
      Speculation: Case fracture, followed by more core deformation.
    - Tensile and Cylic Stress-Strain (graph)
  - SAE8615+DeepCarb.Case+Core Const.Ampl. 4-Point Bending Specimens AISI Iter. 163
  - SAE8615+DeepCarb.Case+Core Periodic Overload, 4-Point Bending Specimens AISI Iter. 164
    - Met.Report FatigueReport(it 163+164) pdf
    - Compare ConstAmpl vs POL Str-2Nf (graph)
  - Compare 8615 Deep Case: Axial and Bend tests
    - Compare Core only: Axial vs Bending (graph)
    - Compare Core(Axial and Bend) vs Case+Core(Axial) (graph)
    - Compare Core-Axial with Case+CoreBending (graph)
    - Compare Case+Core(Axial) vs Case+Core(Bending) (graph)
- SAE8615 Deep vs Shallow Case Comparisons
  - Compare Shallow vs Deep Case Props Axial (courtesy G.Fett, AISI)
  - Compare Shallow vs Deep Case Strain_Life Bending (courtesy G.Fett, AISI)
- SAE8615 series Compare Bending with 8620(+carb) Axial Tests
  - Compare Const.Ampl. Bending with Axial, Case and Core (graph) AISI Iter159, 163
  - Compare Const.Ampl. Bending with Axial Case and Core Plus Core Mean Stress Correction (graph) AISI Iter159, 163
- gnuplot commands for plotting above graphs (text file)
SAE8620 series
- SAE8620 311_BHN Const. Ampl. tests (AISI Iter. 119 )
- SAE8620 311_BHN Periodic Overload tests (AISI Iter. 143 )
  Simul.Core of Carburized part
  Partial Tensile Strain-Life Met.Report FatigueReport
- SAE8620 352_BHN Const. Ampl. tests (AISI Iter. 120 )
- SAE8620 352_BHN Periodic Overload tests (AISI Iter. 144 )
  Simul.Core of Carburized part
  Partial Tensile Cyclic Met.Report FatigueReport
- SAE8620 381_BHN Const. Ampl. tests (AISI Iter. 121 )
- SAE8620 381_BHN Periodic Overload tests (AISI Iter. 145 )
  Simul.Core of Carburized part
  Partial Tensile Cyclic Met.Report FatigueReport
- SAE8620 430_BHN __ | __ Fitted __ | __ Calculator (AISI Iter. 39 )
  Typical Core of Carburized part
  Tensile Tensile+Cyclic FatigueReport
- SAE8620 583_BHN __ | __ Fitted __ | __ Calculator Thru Carburized (AISI Bar Iter. 38)
  (Beware of extensive scatter in Results!)
  Tensile Tensile+Cyclic FatigueReport
- SAE8620 615 BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter. 71)
  MacSteel, Thru Carburized HRc=58 on surface, (0.030 Sulfur).
  Subsurface initiation at long life.
  Micro100X Micro500X Micro
  Tensile Tensile+Cyclic FatigueReport
- SAE8620 615 BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter. 62)
  Ispat Steel, Carburized Case+Core HRc=58 on surface, ( 0.027 Sulfur).
  Subsurface initiation at long life.
  MicroCase100X MicroCase500X MicroCore100X MicroCore500X
  PartialTensile Tensile+Cyclic Hardness Residual Stress FatigueReport
- SAE8620 615 BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter. 70)
  MacSteel, Carburized Case+Core HRc=58 on surface, (0.030 Sulfur).
  Subsurface initiation at long life.
  CaseInclusions MicroCase100x MicroCase500x MicroCase
  CoreInclusions MicroCore100x MicroCore500x MicroCore
  TransitionInclu. TransitionMicro
  Tensile Tensile+Cyclic Hardnesss Residual Stress FatigueReport
- Section Profiles: Iter. 62+70 Hardness Iter. 62+70 Residual Stress
- Compare plots: Strain-Life Neuber
- SAE8620 688 BHN Thru Carbur,Vacuum, Simul.Case, ConstAmpl. HRc=62 (AISI Bar Iter. 165)
  SAE8620 688 BHN Thru Carbur,Vacuum, Simul.Case PeriodicOverload HRc=62(AISI Bar Iter. 166)
  Met.Report Microstructure, iter.165
  (Cyclic is above Ultimate probably due to retained Austenite transforming.
  Mean stress of 1/2 life loops were not reported.)
  Example of compressive mean stress in strain control tests (graph)
  Tensile+Cyclic FatigueReport
- Percent Bainite Study:
  - All have same chemistry. with 0.032 wt% Sulfur:
    Chem.= 0.21wt%C .93Mn .009P .032S .25Si .15Cu .46Ni .50Cr .20Mo
    0V 0Nb .024Al 0Pb .002Ti 0Ca .01Co 0Zr .0003B .01Sn 9ppm_O 63ppm_N.
  - Note that except for the 100%Bainite samples all the iterations had
    a case+core type cross setion. See hardness traverse and Met. reports.
  - Hardness Traverses
  - The metallurgical reports are appended to the Fatigue Reports.
  - Iters.88,89,90 Fisheye Crack Presentation
    Surface Initiation= Blue Points, Fisheye= Red, Unknown= Black
  - Fracture Surface (fisheye) observations for Iter 88, 89, 90 (pdf of hand written notes)
  - AutoSteel SMDI Blog 38B March 2018 Greg Fett, SMDI
- SAE8620 670 BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter. 87)
  Thru Carburized, 0% Bainite 20% Retained Aust., HRc= 62(surface)
  Met.Report MicroSurf-Lowx MicroSurf-Highx MicroCore-Lowx MicroCore-Highx
  Tensile Tensile+Cyclic Strain-Life FatigueReport
- SAE8620 722 BHN Thru Carburized, 25% Bainite __ | __ Fitted __ | __ Calculator (AISI Bar Iter. 88)
  Plot Surface Initiation vs Fisheye internal crack
  Met.Report MicroSurf-Lowx MicroSurf-Highx MicroCore-Lowx MicroCore-Highx
  Tensile Tensile+Cyclic FatigueReport
- SAE8620 688 BHN Thru Carburized, 50% Bainite __ | __ Fitted __ | __ Calculator (AISI Bar Iter. 89)
  Met.Report MicroSurf-Lowx MicroCenter-Highx
  Tensile Tensile+Cyclic FatigueReport
  Plot Surface Initiation vs Fisheye internal crack
- SAE8620 615 BHN Thru Carburized, 75% Bainite __|__ Fitted __|__ Calculator (AISI Bar Iter. 90)
  Met.Report MicroSurface-LowX MicroSurface-HighX MicroCenter-LowX MicroCenter-HighX
  Tensile Tensile+Cyclic FatigueReport
  Plot Surface Initiation vs Fisheye internal crack
- SAE8620 469 BHN Thru Carburized, 100% Bainite __|__ Fitted __|__ Calculator (AISI Bar Iter. 95 )
  (Beware of scatter in long-life results )
  Met.Report
  Tensile Tensile+Cyclic FatigueReport
- Merged SAE8620 (graph) Compare Case(all above) with Core (Iter 39) (without Iter 38)
- Fitted File for 8620case
- Neuber Plot with Fitted File(graph) for 8620case
- Rotating Bending Specimens:
  SAE8620 Rotating Cantelever Bend test (AISI Bar Iter 171)
  Hardness Traverse
  Case Micrographs
  Core Micrographs
  Final Report pdf
  Compare:
  Compare Rotating Bend to Axial Case StrainAmpl vs 2Nf graph
  Compare Rotating Bend to Axial Case NeuberStressAmpl vs 2Nf graph
- Gear Tooth Bending Specimens:
  
  Meritor Tests on Carburized 8620 Gear Tooth.( AISI Iter. 42)
  Surface HRc=60.8, Core HRc=35.7 Tooth Kt=1.6 R=0.1
  Cycles to Initiation
  FatigueReport pdf
SAE86B20 series
- SAE86B20 627_BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter 83)
  Thru Carburized(Vacuum), HRc=59
  Tensile Tensile+Cyclic Met.Rep.(doc) FatigueReport
- SAE86B20 401_BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter 82)
  Quench+Temper Simulated Core, HRc=43
  PartialTensile Tensile+Cyclic Met.Rep.(doc) FatigueReport
- SAE86B20 508_BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter 75)
  Thru Carburized(Atmosphere), HRc=63
  Tensile Tensile+Cyclic Met.Rep.(doc) FatigueReport
- SAE86B20 336_BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter 74)
  Quench+Temper Simulated Core, HRc=36
  PartialTensile Tensile+Cyclic Met.Rep.(doc) FatigueReport
SAE8695 series
- SAE8695 539_BHN Without IGO __ | __ Fitted __ | __ Calculator (AISI Bar Iter 40)
  Received same heat treat as Carburized, but without carbon atmosphere.
  Significant diff. in monotonic Tens vs Comp. Probaly due to Retained Austenite?
  Monotonic and Cyclic Stress-Strain FatigueReport
- SAE8695 539_BHN With IGO __|__ Fitted __|__ Calculator (Beware of scatter in Results! )(AISI Bar Iter 41)
  Lab melted simulated carburized case
  Significant diff. in monotonic Tens vs Comp. Probaly due to Retained Austenite?
  Monotonic and Cyclic Stress-Strain FatigueReport
SAE8822 series
- SAE8822 625_BHN Thru Carburized __ | __ Fitted __ | __ Calculator (Beware of scatter)(AISI Bar Iter 60)
  Thru carburized simulated case
  Full Monotonic Stress-Strain
- SAE8822 252_BHN __ | __ Fitted __ | __ Calculator (AISI Bar Iter 59)
  Simulated carburized Core HRc=55
  Full Monotonic Stress-Strain
- SAE8822 High Side Chem. vs Low Side Chem. Comparison:
- Low Side Chem.:
  wt% .21C .81Mn .02P .026S .26Si .18Cu .46Ni .50Cr .25Mo .005V .002Colum .031Al .01Sn 15ppmO
  - Atmosphere Carburize:
  - SAE8822 LowSide Chem 297 BHN Simul.Carb. Core (Atmosphere), Const.Ampl.Axial (AISI Iter 100)
  - SAE8822 LowSide Chem 297 BHN Simul.Carb. Core (Atmosphere), Periodic Overload. Axial (AISI Iter 104)
    Samples were austenized at 1700F, Quenched in 150F oil, tempered at 1050F to
    to target HRc 25-30 Result 100% tempered Martensite
    (Met. report attached to fatigue report. Hardness Traverse
    Tensile Tensile +Cyclic Met.Rep.(doc) Fatigue Report
    Compare Const.Ampl and Periodic OL Strain-Life graph
  - SAE8822 ThruCarb. Simul.Case BHN=615 Const.Ampl.Axial (AISI iter 101 )
  - SAE8822 ThruCarb. Simul.Case BHN=615 Periodic Overload, Axial (AISI iter 105 )
    Samples austenitized at 1700F with 0.9% carbon potential prior to 150F Oil Quench,
    temper at 425F. Metallurgical report is at end of fatigue test report.
    Microstructure (no etch) shows IGO at surf. Microstr. is martensite with 9.1% Retained Austenite.
    Full Tensile Tensile + Cyclic Met.Rep.(doc) Hardness traverse Fatigue report
    Compare Const.Amp. and Periodic OL tests
  - Vacuum Carburize:
  - SAE8822 LowSide Chem 301 BHN Simul.Carb. Core (Vacuum), Const.Ampl.Axial (AISI Iter 102)
  - SAE8822 LowSideChem 301 BHN Simul.Carb. Core Periodic Overload (AISI Iter 106)
    SAE8822 Low-Side Chem. test specimens were quench and tempered by
    autenitizing at 1700 prior to gas quenching in nitrogen at 18 bar and
    then tempering at 350F to an aim hardness of 30-35HRc.
    PartialTensile Tensile+Cyclic Met.Rep.(doc) Fatigue report
    Compare Const.Ampl. and Periodic Overload (graph)
- High Side Chem.:
  wt% .22C .86Mn .013P .025S .17Si .24Cu .43Ni .54Cr .39Mo .004V .028Al .01Sn
  - Atmosphere Carburize:
  - SAE8822 HighSide Chem 362_BHN Const.Ampl Simul.Carbur.Core __|__ Fitted __|__ Calculator (AISI Iter 108)
  - SAE8822 362_BHN Periodic Overload only Simul. Carbur.Core (AISI Iter 112)
  - SAE8822 362_BHN Combined CA(it.108)+POL(it.112) Simul. Carbur.Core __ | __ Fitted __ | __ Calculator
    Full Tensile Tensile+Cyclic Stress-Strain Met.Rep.(doc) FatigueReport
  - SAE8822 560_BHN Thru Carburized Case Const.Ampl HRc=55 (AISI Iter 109)
  - SAE8822 560_BHN Thru Carburized Case Periodic Overload HRc=55 (AISI Iter 113)
    Met.Report indicates 13.3% Retained Austenite.
    Met.Rep.(doc) Monotonic + Cyclic Stress-Strain FatigueReport
  - Vacuum Caruburize:
  - SAE8822 375 BHN (Vacuum) Sim.Carb.Core (AISI Iter 110 )
  - SAE8822 375 BHN (Vacuum) Sim.Carb.Core Periodic Overload (AISI Iter 114 )
    Hardness see Met.Rep. HRc= 43.5
    Met.Rep.(doc) Tensile+ Cyclic Micro FatigueReport
    Compare CA and POL data graph
- Comparison Results for Low vs High and Atm. vs Vac. available here
Back to Steel Index
Back to Materials Index