MIL-HDBK-5H 1 December 1998

Transcription

1 717 is a high-purity, high-strength Al-Zn-Mg-Cu alloy. In the form of die forgings the alloy is available in the T66, T7, and T72 tempers. Die forgings of 717-T66 develop higher static strength than 77-T6 forgings with fatigue, fracture, and stress-corrosion properties about equivalent to those of 77-T6 forgings. 717-T7-type die and hand forgings develop static strengths about equivalent to those of 77-T6 forgings, with toughness and fatigue properties equal or superior to those of 77-T73 forgings. The T7-type temper provides stress-corrosion resistance and strength characteristics intermediate to those of T76 and T73 in 77. Refer to Section for comments regarding the resistance of the alloy to stress-corrosion cracking, and to Section for comments regarding the weldability of the alloy. The properties of extrusions should be based upon the thickness at the time of quenching prior to machining. Selection of the mechanical properties based upon its final machined thickness may be unconservative; therefore, the thickness at the time of quenching to achieve properties is an important factor in the selection of the proper thickness column. For extrusions having sections with various thicknesses, consideration should be given to the properties as a function of thickness. Material specifications for 717 are presented in Table (a). Room-temperature mechanical and physical properties are shown in Tables (b) through (d). ( Specification Form AMS 18 AMS 19 AMS 179 MIL-A AMS 3 Die forging Die and hand forging Hand forging Forging Extrusion The temper index for 717 is as follows: Section Temper T T7 and T72 (formerly T736, T7362) Figures (a) and (b) show tensile and compressive stressstrain and tangent-modulus curves for extrusion. Figures (a) through (d) present fatigue curves for extrusion. Figures (a) through (f) present tensile and compressive stress-strain and tangent-modulus curves for die and hand forging. Figures (a) and (b) present fatigue curves for die and hand forging. 3-1

2 (! " " ' Specification AMS 18 AMS 19 Form Die forging Temper. T66 T7 a,b Thickness, in < Basis S S A B S S S S Mechanical Properties: F tu, ksi: L. T c. F ty, ksi: L. T c. F cy, ksi: L. ST F su, ksi. F brue, ksi: (e/d = 1.) (e/d = 2.) F brye, ksi: (e/d = 1.) (e/d = 2.) e, percent (S-basis): L. T c. E, 1 3 ksi.. E c, 1 3 ksi. G, 1 3 ksi.. µ.. Physical Properties:, lb/in. 3.. C, Btu/(lb)(F) K, Btu/[(hr)(ft 2 )(F)/ft], 1-6 in./in./f d 6 62 d (at 212F) 76 (at 77F for T66); 9 (at 77F for T736) 12.9 (68 to 212F) a When die forgings are machined before heat treatment, section thickness at time of heat treatment shall determine minimum mechanical properties as long as original (as-forged) thickness does not exceed maximum thickness for the alloy as shown in the table. b Design allowables were based upon data obtained from testing die forgings, heat treated by suppliers, and supplied in T7 temper. c T indicates any grain direction not within ±1 of being parallel to the forging flow lines. F cy (T) values are based upon short transverse (ST) test data. d Specification value. T tensile properties are presented on an S basis only. e Bearing values are dry pin values per Section

3 (! " " 3! ' Specification. AMS 19 and MIL-A Form. Hand forging Temper.. T7 Thickness or Diameter a,b, in Basis. S S S S S Mechanical Properties: F tu, ksi: L.. LT ST F ty, ksi: L.. LT ST F cy, ksi: L.. LT ST F su, ksi: L.. LT ST F bruc, ksi: (e/d = 1.) (e/d = 2.) F bryc, ksi: (e/d = 1.) (e/d = 2.) e, percent: L.. LT ST E, 1 3 ksi.. E c, 1 3 ksi.. G, 1 3 ksi.. µ Physical Properties:, lb/in. 3 C, Btu/(lb)(F). K, Btu/[(hr)(ft 2 )(F)/ft]. 1-6 in./in./f (at 212F) 9 (at 77F) 12.9 (68 to 212F) a When hand forgings are machined before heat treatment, the section thickness at time of heat treatment shall determine the minimum mechanical properties as long as the original (as-forged) thickness does not exceed the maximum thickness for the alloy as shown in the table. b The maximum cross-sectional area of hand forgings in 26 sq. in. c Bearing values are dry pin values per Section

4 (! " " 3! '#$! Specification. AMS 19 and MIL-A Form. Hand forging Temper.. T72 Thickness or Diameter a, in Basis. S S S S S Mechanical Properties: F tu, ksi: L.. LT ST F ty, ksi: L.. LT ST F cy, ksi: L.. LT ST F su, ksi: L.. LT ST F brub, ksi: (e/d = 1.) (e/d = 2.) F bryb, ksi: (e/d = 1.) (e/d = 2.) e, percent: L.. LT ST E, 1 3 ksi.. E c, 1 3 ksi.. G, 1 3 ksi.. µ Physical Properties:, lb/in. 3 C, Btu/(lb)(F). K, Btu/[(hr)(ft 2 )(F)/ft]., 1-6 in./in./f (at 212F) 9 (AT 77F) 12.9 (68 to 212F) a The maximum cross-sectional area of hand forgings is 26 sq.in. b Bearing values are dry pin values per Section

5 !"!" #$! Specification.. AMS 3 Form.. Extrusion Condition. T7311 Cross-Sectional Area, in Thickness or Diameter, b in Basis.. S S Mechanical Properties: F tu, ksi: L LT. F ty, ksi: L LT. F cy, ksi: L LT. F su, ksi F brua, ksi: (e/d = 1.). (e/d = 2.). F brya, ksi: (e/d = 1.). (e/d = 2.). e, percent: L LT. E, 1 3 ksi. E c, 1 3 ksi G, 1 3 ksi µ. Physical Properties:, lb/in. 3. C, Btu/(lb)(F).. K, Btu/[(hr)(ft 2 )(F)/ft].., 1-6 in./in./f (at 212F) 12.9 (68 to 212F) a Bearing values are dry pin values per Section b The mechanical properties are to be based upon the thickness at the time of quench. 3-19

6 Long Transverse n (L-tension) = 1 n (LT-tension) = 8 2 Thickness = in. Cross-sectional area: 32-6 in Strain,.1 in./in. ' (( ) * ) & and Long Transverse 2 n (L and LT - comp. = 13 Thickness = in. Cross-sectional area: 32-6 in Strain,.1 in./in. Compressive Tangent Modulus, 1 3 ksi ' (( * )! )! * ) & 3-2

7 ' (, -)./ *! ) &!! Correlative Information for Figure (a) Product Form: Extrusion 1.8-inch thick, extruded round, 3-3/-inch diameter, extruded rectangle, 2-1/2 x -inch thick, extrusion, unspecified size Properties: TUS, ksi TYS, ksi Temp.,F Specimen Details: inch minimum diameter hourglass gage section 3-inch diameter Surface Condition: 32 RMS gage section specified References: (a), (b), and (c) Test Parameters: Loading - Axial Frequency - Not specified Temperature - 7F Environment - Air No. of Heats/Lots: 11 Equivalent Stress Equation: Log N f = log (S eq ) S eq = S a +.32S m - 1. Standard Deviation in Log (Life) = 18.(1/S eq ) Adjusted R 2 = 8% Sample Size = 96 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 3-21

8 ' (, -)./ *! 1 2 ) &!! Correlative Information for Figure (b) Product Form: Extrusion 1.8-inch thick, extruded round, 3-3/-inch diameter, extruded rectangle, 2-1/2 x -inch thick, extrusion, unspecified size Properties: TUS, ksi TYS, ksi Temp.,F Specimen Details: Circumferential notch, K t = 3.-inch gross diameter.36-inch net diameter.-inch notch radius Circumferential V notch References: (a), (b), and (c) Test Parameters: Loading - Axial Frequency - Not specified Temperature - 7F Environment - Air No. of Heats/Lots: 11 Equivalent Stress Equation: Log N f = log (S eq ) S eq = S a +.2S m Standard Deviation in Log (Life) = 3.92(1/S eq ) Adjusted R 2 = 91% Sample Size = 86 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 3-22

9 ' (, -)./ *! 1 2 ) &!! Correlative Information for Figure (c) Product Form: Extrusion 1.8-inch thick Properties: TUS, ksi TYS, ksi Temp.,F Specimen Details: Circumferential notch, K t =.-inch gross diameter.36-inch net diameter.-inch notch radius References: (a) and (b) Test Parameters: Loading - Axial Frequency - Not specified Temperature - 7F Environment - Air No. of Heats/Lots: 1 Equivalent Stress Equation: Log N f = log (S eq ) S eq = S a +.28S m Standard Deviation in Log (Life) = 3.71(1/S eq ) Adjusted R 2 = 9% Sample Size = 136 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 3-23

10 ' (,! -)./ *! 1 2 ) &!! Correlative Information for Figure (d) Product Form: Extrusion 1.8-inch thick Properties: TUS, ksi TYS, ksi Temp.,F Specimen Details: Circumferential notch, K t = 7.-inch gross diameter.36-inch net diameter.-inch notch radius References: (a) and (b) Test Parameters: Loading - Axial Frequency - Not specified Temperature - 7F Environment - Air No. of Heats/Lots: 9 Equivalent Stress Equation: Log N f = log (S eq ) S eq = S a +.27S m Standard Deviation in Log (Life) = (1/S eq ) Adjusted R 2 = 92% Sample Size = [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 3-2

11 2 n () = n (Transverse) = 2 Thickness 3. in. Transverse Strain,.1 in./in. ' (+( ) * )! Transverse 2 n () = n (Transverse) = 2 Thickness 3. in Strain,.1 in./in. Compressive Tangent Modulus, 1 3 ksi ' (+( * )! * )! * )! 3-2

12 Long Transverse Short Transverse 2 n () = 3 n (Long Transverse) = 26 n (Short Transverse) = 13 Thickness. in Strain,.1 in./in. ' (+( ) * )! Long Transverse Short Transverse Long Transverse 2 Short Transverse n () = 27 n (Long Transverse) = 17 n (Short Transverse) = 19 Thickness. in Strain,.1 in./in. Compressive Tangent Modulus, 1 3 ksi ' (+(! * )! * )! * )! 3-26

13 2 Long Transverse Short Transverse n (L-tension) = 12 n (LT-tension) = 13 n (ST-tension) = 1 Thickness =.1 -. in Strain,.1 in./in. ' (+( ) * ) +! and Long Transverse Short Transverse 2 n (L-comp.) = 13 n (LT-comp.) = 1 n(st-comp.) = 17 Thickness =.1 -. in Strain,.1 in./in. Compressive Tangent Modulus, 1 3 ksi ' (+( * )! * )! * ) +! 3-27

14 ' (+, -)./ *! 1 2 )!!! Correlative Information for Figure (a) Product Form: Die forging, 2. to 3.-inch thick, unspecified thickness Properties: TUS, ksi TYS, ksi Specimen Details: Circumferential notch, K t = 3.3-inch gross diameter.2-inch net diameter Rectangular notched.1 x.2-inch Surface Condition: Not specified Test Parameters: Loading - Axial Frequency - 12 cpm unspecified Temperature - 7F Environment - Air No. of Heats/Lots: 13 Equivalent Stress Equation: Log N f = log (S eq -7.1) S eq = S a +.37S m Standard Deviation in Log (Life) = 7. (1/S eq ) Adjusted R 2 = 83% References: (d), (c), (d), (a), (b), and (c) Sample Size = 137 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 3-28

15 ' (+, -)./ *! )!!! *! Correlative Information for Figure (b) Product Form: Hand forging, 2. to 6.2-inch thick Properties: TUS, ksi TYS, ksi Temp.,F Specimen Details: Uniform gage length 3.-inch diameter Hourglass gage section.2-inch minimum diameter References: (d) (c) and (d) Test Parameters: Loading - Axial Frequency - 12 cpm Temperature - 2F Environment - Air Equivalent Stress Equation: Log N f = log (S eq ) S eq = S max (1-R) Standard Deviation in Log (Life) = 23.33(1/S eq ) Adjusted R 2 = 76% [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 3-29