# # SAE8620 Thru Carburized simulated Case, HRc=58 # Material cyclically hardens. # MacSteel Ht. 1M35594 ElecFurnace, RotaryCast 170mm billet, HotRoll 25.4mm # Specimens machined, heat treated, ground and polished. # Carburized, 100%Martensite, ASTM Grain Size 5 to 6, # Chem.: 0.20wt%C .96Mn .008P .030S .24Si .15Cu .53Ni # .55Cr .22Mo 0Ca .007Sn 88ppm_Ni Inclusions: TypeA=2-2.5Thin # All subsurface crack initiation sites fell in a region # of 0.055" to 0.075" from surface with inclusion initiation. See data. # Test: UoToledo F.Yin and A.Fatemi April 2004 #FileType= strain_life #DataType= raw #Name= SAE8620 #Name= Carburized #Name= AisiIt_71 #Stress_units= MPa #Strain_units= strain #Sy= 1125.3 #Su= 1868.7 #eu= 0.0169 strain at Su #E= 204869. average of initial obsv. #reported #E= 207900 tensile test #monotonic_K= 11109.0 #monotonic_n= 0.372 #FractureStrain= 0.0175 (from monotonic curve plot) #FractureStress= 1857. #%RA= 0.1 % #%Elongation= 1.7 % over 0.3" gauge #MaterialForm= bar #FailureDef= 50% load drop #Hardness, Rockwell C= 58.2 at center of gage section #BHN= 615 converted from HRc #StrAmp 2Nf StsAmp So CalcPlasStr InitialModulus 0.0098 138 1899 -352.4 0.00068 201000 #IGL 0.0100 148 1938 -367.7 0.00062 204000 #IGL 0.0100 356 1958 -308.1 0.00062 203000 #IGL 0.0080 1682 1599 -324.8 0.00030 205000 #IGL 0.0080 2204 1587 -324.1 0.00035 204000 #IGL 0.0080 3960 1580 -333.7 0.00038 203000 #IGL 0.0064 10222 1285 -234.9 0.00022 204000 #IGL 0.0064 29960 1300 -225.8 0.00014 206000 #IGL 0.0050 47132 1010 -79.7 0.00013 203000 #IGL 0.0050 72014 1011 5.1 0.00000 204869 #IGL avrg. E 0.0065 82256 1297 -240.3 0.00024 204000 #fisheye 0.0050 146624 1011 5.1 0.00000 204869 #fisheye, avrg. E 0.00350 539236 724 0.0 0.00000 206857 #fisheye 0.00400 563866 827 3.3 0.00000 206750 #fisheye 0.00400 1581068 827 3.3 0.00000 206750 #fisheye 0.00375 3143110 776 2.9 0.00000 206933 #fisheye 0.00400 6356444 827 3.3 0.00000 206750 #fisheye 0.00350 10000000 724 0.0 0.00000 206857 #Runout # average initial Emod 204869 #Martensite, %= 100 #ASTM Grain Size No. (Min to Max)= 5 to 6 #Carbon, %= 0.2 #Manganese, %= 0.96 #Phosphorus, %= 0.008 #Sulfur, %= 0.03 #Silicon, %= 0.24 #Copper, %= 0.15 #Nickel, %= 0.53 #Chromium, %= 0.55 #Molybdenum, %= 0.22 #Aluminum, %= 0.020 #Calcium, %= 0.00 #Tin, %= 0.010 #Nitrogen, ppm= 88 # #