MIL-HDBK-5H 1 December 1998

Transcription

1 Alloy 17-4PH is a precipitation-hardening, martensitic stainless steel used for parts requiring high strength and good corrosion and oxidation resistance up to 600F. The alloy is available in all product forms. Manufacturing Considerations 17-4PH is readily forged, machined, welded, and brazed. Machining requires the same precautions as the austenitic stainless steels except that work-hardening is not a problem. Best machinability is exhibited by Conditions H1150 and H1150M. A dimensional contraction of to and to in./in. occurs upon hardening to the H900 and H1150 conditions, respectively. This fact should be considered before finish machining prior to aging treatment. When permanent deformation is performed, such as cold straightening of hardened parts, reaging is recommended to minimize internal stresses. Alloy 17-4PH can be fusion welded with any of the normal processes using 17-4PH filler metal without preheat. For details up to ½-inch thickness, Condition A is satisfactory prior to welding, but for heavy sections, an overaged condition (H1150) is recommended to preclude cracking. After welding, weldments should be aged or solution treated and aged. Alloy 17-4PH castings are produced in sand molds, investment molds, and by centrifugal casting. While 17-4PH has good castability, it is subject to hot-tearing, so heavy X or T sections, sharp corners, and abrupt changes in section size should be avoided. Alloy 17-4PH castings are susceptible to microshrinkage which will decrease the ductility but have no effect on the yield or ultimate strength. During heat treatment, care must be exercised to avoid carbon or nitrogen contamination from furnace atmospheres. Combusted hydrocarbon and dissociated ammonia atmospheres have been sources of contamination. Air is commonly used and both vacuum and dry argon are effective for minimizing scaling. Oxides formed during solution treating in air may be removed by grit blasting or abrasive tumbling. Alloy 17-4PH can be heat treated to develop a wide range of properties. Heat treatment procedures are specified in applicable material specifications and MIL-H Design and Environmental Considerations For tensile applications where stress corrosion is a possibility, 17-4PH should be aged at the highest temperature compatible with strength requirements and at a temperature not lower than 1025F for 4 hours minimum. The impact strength of 17-4PH, especially large size bar in the H900 and H925 conditions, may be very low at subzero temperatures; consequently, the use of 17-4PH for critical applications at low temperatures should be avoided. For non-impact applications, such as valve seats, parts in the H925 condition have performed satisfactorily down to -320F. The H1100 and H1150 conditions have improved impact strength so that parts made from small diameter bar can be used down to -100F with low risk. For critical low temperature applications, a similar alloy, 15-5PH (consumable electrode vacuum melted), should be used instead of 17-4PH because of its superior impact strength at low temperature. Specifications and Properties Material specifications for 17-4PH are presented in Table (a). Room temperature mechanical and physical properties for various conditions of 17-4PH products are presented in Table (b) through (f). The physical properties of this alloy at room and elevated temperatures are presented in Figure

2 '()* "( &((* +(,#$ (* * Specification Form AMS 5604 AMS 5643 AMS 5342 AMS 5343 AMS 5344 Sheet, strip, and plate Bar, forging, and ring Investment casting (H1100) Investment casting (H1000) Investment casting (H900) Elevated temperature curves for various mechanical properties are presented in Figures through Unnotched and notched fatigue information at room temperature is presented in Figures (a) through (c). Elevated temperature curves for tensile yield and ultimate strengths are depicted in Figure Room temperature stress-strain and tangent-modulus curves are shown in Figures (a) and (b). Room temperature stress-strain and tangent-modulus curves for castings are shown in Figures (a) and (b). Notched fatigue information is presented in Figure for bar. Notched fatigue information is presented in Figure for bar. Elevated temperature curves for tensile yield and ultimate strengths are shown in Figure

3 '()* ") - &((* ( #.(* #+,#$ (* * + ( #*( Specification... AMS 5604 Form... Sheet, strip a, and plate Condition... H900 H925 H1025 H1075 H1100 H1150 Thickness, in Basis... S S S S S S Mechanical Properties: F tu, ksi: L LT F ty, ksi: L LT F cy, ksi: L LT F su, ksi F bru, ksi: (e/d = 1.5) (e/d = 2.0) F bry, ksi: (e/d = 1.5) (e/d = 2.0) e, percent: LT... b b b b b b E, 10 3 ksi E c, 10 3 ksi G, 10 3 ksi µ Physical Properties:, lb/in (H900), (H1075), (H1150) C, K, and... See Figure a b Test direction longitudinal for widths less than 9 inches; long transverse for widths 9 inches and over. See Table (c). '()* " &// 0*( 1(*,#$ + ( #*( Thickness through through through e, percent (LT) H900 H925 H1025 H1075 H1100 H

4 '()* " - &((* ( #.(* #+,#$ (* * ') ( 2 Specification... AMS 5643 Form... Forging, tubing, and rings Condition... H900 H925 H1025 H1075 H1100 H1150 H1150M a Thickness, in.... <8.000 Basis... S S S S S S S Mechanical Properties: F tu, ksi: L T F ty, ksi: L T F cy, ksi: L T F su, ksi F bru, ksi: (e/d = 1.5) (e/d = 2.0) F bry, ksi: (e/d = 1.5) (e/d = 2.0) e, percent: L E, 10 3 ksi E c, 10 3 ksi G, 10 3 ksi µ Physical Properties:, lb/in (H900), (H1075), (H1150) C, K, and... See Figure a Not covered by AMS S values are producers guaranteed minimum tensile properties

5 '()* " - &((* ( #.(* #+,#$ (* * ( Specification... AMS 5643 Form... Bar Condition... H900 H925 H1025 H1075 H1100 H1150 H1150M a Thickness or diameter, in.. <8.000 Basis... A B A B S A B S A B S a Mechanical Properties: e F tu, ksi: L T F ty, ksi: L b c T F cy, ksi: L T F su, ksi F bru, ksi: (e/d = 1.5) d d 228 d... (e/d = 2.0) d d 289 d... F bry, ksi: (e/d = 1.5) d d 175 d... (e/d = 2.0) d d 208 d... e, percent (S-basis): L E, 10 3 ksi E c, 10 3 ksi G, 10 3 ksi µ Physical Properties:, lb/in (H900), (H1075), (H1150) C, K, and... See Figure a Not covered by AMS S values are producer s guaranteed minimum tensile properties. b S-basis. Rounded T 99 value = 157 ksi. c S-basis. Rounded T 99 value = 136 ksi. d Bearing values are dry pin values per Section e Design allowables were based upon data from samples of material, supplied in the solution treated condition, which were aged to demonstrate response to heat treatment by suppliers

6 '()* " - &((* ( #.(* #+,#$ (* * 3/ 4( Specification... AMS 5344 AMS 5343 AMS 5342 Form... Investment Casting Condition... a H1000 b H1100 c Location within casting... Any area Basis... S S S Mechanical Properties d : F tu, ksi F ty, ksi F cy, ksi F su, ksi F brue, ksi: (e/d = 1.5) (e/d = 2.0) F brye, ksi: (e/d = 1.5) (e/d = 2.0) e, percent RA, percent E, 10 3 ksi E c, 10 3 ksi G, 10 3 ksi µ Physical Properties:, lb/in (H900) C, K, and... See Figure a Aged at 900 to 925F for 90 minutes. b Aged at 985 to 1015F for 90 minutes. c Aged at 1085 to 1115F for 90 minutes. d Properties apply only when drawing specifies that conformance to tensile property requirements shall be determined from specimens cut from casting or integrally cast specimens. e Bearing values are dry pin values per Section

7 α (H1150) K, Btu/[(hr)(ft 2 )( F)/ft] C, Btu/ (lb)( F) α (H1075) α (H900) 8 6 α, 10-6 in./in./ F K C α - Between 70 F and indicated temperature except from -100 F for 70 F value 2 K - At indicated temperature C - At indicated temperature Temperature, F " 0 /+( +.(* ++,#$ (* * 2-195

8 100 Strength at temperature Exposure up to 1/2 hr 80 Percentage of Room Temperature Strength F cy F su Temperature, F 0 /+( /+.* ( ( */(,#$ $5"" (* * )( ( Strength at temperature Exposure up to 1/2 hr Percentage of Room Temperature Strength F bry F bru Temperature, F! 0 /+( )( */( ( )(.*,#$ $5"" (* * )( ( 2-196

9 100 E & E C Percentage of room Temperature Modulus Modulus at temperature Exposure up to 1/2 hr TYPICAL Temperature, F, 0 /+( * ( /+ /* 0 ( 0,#$ $5"" (* * )( ( 2-197

10 (,#$ $5"" )( *(* Correlative Information for Figure (a) Product Form: Bar, 1-inch and 1-1/8-inch diameter Properties: TUS, ksi TYS, ksi Temp,F Specimen Details: RT Surface Condition: Polished References: (a) Unnotched 1.25-inch gross diameter inch net diameter Test Parameters: Loading - Axial Frequency cpm Temperature - RT Environment - Air No. of Heats/Lots: Not specified Equivalent Stress Equation: Log N f = log (S eq ) S eq = S max (1-R) 0.52 Standard Error of Estimate = Standard Deviation in Life = R 2 = 38% Sample Size: = 42 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 2-198

11 ! " #$%& &'"" ( )() Correlative Information for Figure (b) Product Form: Bar, 1-inch and 1-1/8-inch diameter Properties: TUS, ksi TYS, ksi Temp,F Specimen Details: RT Circumferential V-Groove, K t = 3.0 Gross Net Notch diameter diameter radius inches inches inches flank angle, Surface Condition: Polished Reference: (a) Test Parameters: Loading - Axial Frequency - Not specified Temperature - RT Environment - Air No. of Heats/Lots: Not specified Equivalent Stress Equation: Log N f = log (S eq ) S eq = S max (1-R) 0.67 Standard Error of Estimate = Standard Deviation in Life = R 2 = 93% Sample Size: 39 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 2-199

12 , ",#$ $5"" )( *(* Correlative Information for Figure (c) Product Form: Bar, inch diameter, vacuum melted Properties: TUS, ksi TYS, ksi Temp,F Specimen Details: 207 RT Circumferential V-Groove, K t = inch gross diameter inch net diameter inch notch radius, n 60 flank angle, Surface Condition: Machined and aged Reference: (b) Test Parameters: Loading - Axial Frequency cpm Temperature - RT Environment - Air No. of Heats/Lots: 1 Equivalent Stress Equation: Log N f = log (S eq ) S eq = S max (1-R) 0.51 Standard Error of Estimate = Standard Deviation in Life = R 2 = 82% Sample Size: = 22 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 2-200

13 100 Percentage of Room Temperature Strength F ty F tu Strength at temperature Exposure up to 1/2 hr Temperature, F 0 /+( * */( ( *.*,#$ $5"" $5% $"% ( $"% (* * )( 2-201

14 200 Longitudinal H H1125 Stress, ksi H1150 Ramberg-Osgood 40 n (H900) = 11 n (H1025) = 24 n (H1150) = 13 TYPICAL Thickness: in Strain, in./in. ( '.+(* * ( ( / /+( ( ( (,#$ (* * )( H1025 Longitudinal H1025 Stress, ksi H1150 Ramberg-Osgood H n (H1025) = 22 n (H1150) = 13 TYPICAL Thickness: in Strain, in./in Compressive Tangent Modulus, 10 3 ksi ) '.+(* /+ ( ( /+ ( /* ( / /+( ( ( (,#$ (* * )( 2-202

15 6WUHVV NVL 5DPEHUJ2VJRRG Q 7<3,&$/ 7KLFNQHVV LQ 6WUDLQ LQLQ! ( '.+(* * (,#$ $""" (* * ( ( / /+( Stress, ksi Ramberg-Osgood 40 n = 13 TYPICAL Thickness: in Strain, in./in Compressive Tangent Modulus, 10 3 ksi! ) '.+(* /+ ( ( /+ ( /*,#$ $""" (* * ( ( / /+( 2-203

16 ,! " ( )(,#$ $"% (* * )( *(* ( * ( Correlative Information for Figure Product Form: Bar, 2 x 6 inches Properties: TUS, ksi TYS, ksi Temp,F Longitudinal RT Long RT Transverse Longitudinal 280 RT (notched) Long 275 RT Transverse (notched) Specimen Details: Notched V-Groove, K t = inch gross diameter inch net diameter inch root radius, r 60 flank angle, Surface Condition: Notched: Ground notch Reference: Test Parameters: Loading - Axial Frequency cpm Temperature - RT Environment - Air No. of Heats/Lots: 3 Equivalent Stress Equation: Log N f = log (S eq ) S eq = S max (1-R) Standard Error of Estimate = Standard Deviation in Life = R 2 = 67% Sample Size: = 44 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 2-204

17 %, ",#$ $"" )( *(* Correlative Information for Figure Product Form: Bar, inch diameter Properties: TUS, ksi TYS, ksi Temp,F Specimen Details: 151 RT Circumferential V-Groove, K t = inch gross diameter inch net diameter inch notch radius, r 60 flank angle, Surface Condition: Machined then aged Reference: (b) Test Parameters: Loading - Axial Frequency cpm Temperature - RT Environment - Air No. of Heats/Lots: Equivalent Stress Equation: Log N f = log (S eq ) S eq = S max (1-R) 0.69 Standard Error of Estimate = Standard Deviation in Life = R 2 = 71% Sample Size: = 21 [Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.] 2-205

18 100 Percentage of Room Temperature Strength F tu F ty Strength at temperature Exposure up to 1/2 hr Temperature, F 0 /+( * */( ( *.*,#$ $%" (* * )( 2-206