# # Fitted Curve ! # SAE8620 Thru Carburized 75%Bainite Rc=58 # Material cyclically hardens to elastic conditions. # ElecFurnace, LadleRefined, ConCast(152x152mm) HotRolled to 29.7mm bar # Specimens machined from the cylindrical bars and case carburized then # reaustenitized and isothermally transformed at 450F for 150min. to # achieve 25% Martensite and 75%Bainite microstructure. Surface hardness # Rc=60 decreases to Rc=54 at core. # Inclusions: TypeA=1.2T, TypeB=0.5T 0.3H, TypeC=0.2T, TypeD=1.5T 0.5H # Test: UoWaterloo, A.Rteil and T.Topper # saedigcurve_v2.2.f starts. #FileType= strain_life #DataType= fitted #Name= SAE8620 #Name= AisiIt_90 #Stress_units= MPa #Strain_units= strain #Sy= 1314.0 #Su= 1883.0 #E= 202500 #monotonic_K= 4891.0 #monotonic_n= 0.212 #FractureStrain= 0.022 #FractureStress= 1883 #%RA= 0 (not measurable) #MaterialForm= bar #FailureDef= 50% load drop #Hardness, Rockwell C= 58 #BHN= 615 #Basic Oxygen= False #Electric Furnace= True #Vacuum Degas= False #Ladle Refined= True #Ingot Cast= False #Continuous Cast= True #Bainite, %= 75 #Martensite, %= 25 #Carbon, %= 0.21 #Manganese, %= 0.83 #Phosphorus, %= 0.009 #Sulfur, %= 0.032 #Silicon, %= 0.25 #Copper, %= 0.15 #Nickel, %= 0.46 #Chromium, %= 0.5 #Molybdenum, %= 0.2 #Vanadium, %= 0.00 #Columbium/Niobium, %= 0.00 #Aluminum, %= 0.024 #Lead, %= 0.001 #Titanium, %= 0.002 #Calcium, %= 0.00 #Cobalt, %= 0.006 #Zirconium, %= 0.001 #Boron, %= 0.0003 #Tin, %= 0.006 #Oxygen, ppm= 9 #Nitrogen, ppm= 63 # SAE8620 AisiIt_90 BHN= 615 Fn= 0 # Monotonic Props. Cyclic Props. #ELAS. MOD.= 29370. KSI, 203. GPA K' = 0.0 KSI, 0.MPA #YIELD,0.2%= 191. KSI, 1314. MPA N' = 0.0000 #ULT. STRG.= 273. KSI, 1883. MPA F. STRG COEF= 448.9 KSI, 3095.MPA #K = 0.0 KSI, 0. MPA F.STRG EXP, b=-0.0963 #N = 0.0000 FAT DUCT COEF= 0.0000 #RED. IN AREA = 0.0 F.DUCT EXP, c= 0.0000 #T. FRAC. STG.= 273.1 KSI, 1883. MPA Exp Cyc Yld = 0. Ksi, 0.MPA #T. FRAC. STR.= 0.022 Fit Cyc Yld = 0. Ksi, 0.MPA #No. fatigue data points= 18 # # NOTE!! The Following Points are <b>FITTED DATA:</b>#NOTE!! Fitted Stress computed using Experm. K' and n' # NOTE!! No cyclic plasticity. Fitted curve is from elastic strain vs life curve. #Stress_Units= MPa # Total Strain 2Nf Stress Mean Plastic Strain Initial # Amp Amp Stress Amp Elastic Mod. 0.01529 1 3096. 0. 0. 202500. #Fitted_point 0.00786 1000 1592 0. 0. 202500. #Fitted_point 0.00378 2000000 765 0. 0. 202500. #Fitted_point 0.00378 10000000 765 0. 0. 202500. #Fitted_point #