autofrettage process

United States Patent [19] [11] 4,417,459 Tomita [45] Nov. 29, 1983

[54] AUTOFRETTAGE PROCESS Primary Examiner—Lowell A. Larson . . . Assistant Examiner-David B. Jones

[75] Inventor: Nobuya Tomita, Fair?eld, Ohio Attorney’ Agent, or Firm_Kenneth D. Tremain

[73] Assignee: National Distillers and Chemical 57 ABSTRACT Corporation, New York, NY. [ 1 _

An autofrettage process which relates to the autofret [21] APP1- NO-I 288,432 tage of thick-walled cylinders through the cyclical ap

- I L 1981 plication of high pressure to the internal bore of the [22] Flled J“ 30’ cylinder. The invention encompasses the autofrettage of [51] Int. Cl.3 ............................................ .. B21D 26/02 cylindrical members in cyclical ressure stages each of P [52] US. Cl. ......................................... .. 72/56; 72/61; a few seconds to a few minutes in duration during each

29/1. 1 1; 29/446 of which the bore of the cylinder being autofrettaged is [58] Field Of Search ................... .. 29/1.11, 446; 72/60, subjected to a pressure in the range of about zero to

72/56, 53, 61 100,000 psi and, preferably 40,000 to 100,000 psi. Prefer ' . ably, the pressurizable hydraulic ?uid medium utilized

[56] References Clted for the autofrettage is ethylene glycol or hydraulic oil, U.S. PATENT DOCUMENTS or any similar ?uid which will not freeze or solidify at

1 329 762 2/1920 Guy .................................... .. 29/1.11 the Pressures encountered during the inventive Pr°°ess~ 1,391,009 9/1921 Schneider ....... .. ..

1,495,587 5/1924 Grimm ............................... .. 29/ 1.11 29 Claims, 20 Drawing Figures

J28

US. Patent Nov. 29, 1983 Sheet 1 of 20 4,417,459

J28

FIG!


NOE 50E .QE nzmm? 62 mo“. H.550 z_<Ew|mmwEw .959 x mjmnw

l

0v 0m 0m 09 ON_ OE Ow_ Om_ Om U91); 9 SSHHLS


FIG?)

US. atent Nov. 29, 1983 ‘ Sheet4 of 20 4,417,459

r| = INNER RADIUS (H40)

r2 = CENTER RADIUS(2.755)

r0 = PLASTICALLY YIELDED RADIUS

FIG.4


@OE

~______ - _


220 -

ZOO -

0 mm x

0 9m /K 0m 8 m u mm E wm A a

0 5R 0 4 O 3 o 2 U

m

__ 00 hi4

—2oo— "9 -220

-240

STRESS DISTRIBUTION OF THlCK-WALLED CYLINDER (CLOSED-END) AT I8TH REVERSAL TO ZERO PRESSURE

FIGB

US. Patsnt Nov. 29, 1983 Sheet 9 of 20 4,417,45

@QI _ _ _ _ _ _ _ 1 _ _ _ _ _ _ _ _ _

Om

_ _ _

ION lom 10¢ low low ION low low 409

m_ E : m hmm_

Us») ‘aanssaad


$-95 $2315 .Zizwwzg . mm 8 Q 9 s s gmwkw .qmm_ o

_ _ _ _ _

Om mm wm vm

u _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _

ION low low low. low |ON low 05x)‘ aanssaud

U.S. Pat?nt Nov; 29, 1983 Sheet 11 of 20 4,417,459

MW O.n|v -m M l 7: O N,

w -6 m

| m

‘.0 s -m w

3 I

| - .m

0 E F

IQ F

I E I ./m 0

9 -m

7 -

5 -w/m

3 |

| -m/m -o/m 4 .Mo 0

-2 6 -4 2

_________________ O 0000000000000 mmmwmmmumss7es4szl 44:14PM“ resgdmom m5 2 wmwEm mzBmtw

EFFECTIVE STRESS-EFFECTIVE STRAIN AT I.D. OF THICK-WALLED CYLINDER (CLOSED-END) REPEATED AUTOFRETTAGE BETWEEN IOO ksi AND ZERO

FIGII


0 6.0 -m m I Nm

0 7:. 1% W A - m

?lv |% S

l E I W

B .0 T

-mmm F

u - "U

m

9 l

7 1/5 5 -m

3

l/m l 10

6 ./P_ ‘%/m -U8 0

-2 6 |%4 2

_ n_v______m_____ __n_v__ 0 000000 00000 000 00 m MBQHM98765432 lwniqwnwpw EFFECTIVE STRESS-EFFECTIVE STRAIN AT LD. OF THlCK-WALLED CYLINDER (OPEN-END) REPEATED AUTOFRETTAGE BETWEEN IOO ksi AND ZERO

FIGIZ

US. Patent Nov. 29, 1983 Sheet 13 0f 20 4,417,459

60 70/80/90 I00 I

30

:9; 5.. :ambnb .wmwEm

RELATIVE WALL THICKNESS ("/o) _ _ _ _ O O 0 ii

_ _

—I80—

-200

—220" -240 —

STRESS DISTRIBUTION OF THICK-WALLED CYLINDER (CLOSED-END) AT FIRST REVERSAL TO IOO ksi PRESSURE

FIGI3

US. Patent

I l 65 3 O O I I

Nov. 29, 1983 Sheet 14 of 20 4,417,459

IO 20 3b 40 5'0

RELATIVE WALL THICKNESSWJ

STRAIN DISTRIBUTION. OF THICK-WALLED CYLINDER (CLOSED-END) AT FIRST REVERSAL TO IOO ksi PRESSURE


N N O I

00 1|

0000 III' ql

STRESS, a ,06 ,0, p24 ksi)

J l i

lofzo 3o 40 5b 60 70 so 910 I60

-402 RELATIVE WALL THICKNESS cm

STRESS DISTRfBUTION OF THlCK-WALLED CYLINDER (CLOSED-END) AT SECOND REVERSAL TO ZERO PRESSURE

US. Patsnt

STRAIN, €,e6,er ,ez ,(x IO'S)

Nov. 29, 1983 Sheet 16 of 20 4,417,459

220 200

RELATIVE WALL THICKNESS (°/°)

~2OO —2 20

-240

STRAIN DISTRIBUTION OF THICK-WALLED CYLINDER (CLOSED-END) AT SECOND REVERSAL TO ZERO PRESSURE

FIG.I6

US. Patent Nov. 29, 1983 Sheet 17 0f 20 4,417,459

220 200

2 I80

é; I40 Q I20

83 80 lg so

a 40 E 20 U) l I I l I l I I

40 5O 6O 7O 8O 90/ I60

RELATIVE WALL THICKNESS (7°)

| O I

—220

—240

STRESS DISTRIBUTION OF THICK-WALLED CYLINDER (CLOSED~END) AT I7“I REVERSAL TO IOO ksi PRESSURE

FIGIT

US. Patent

-200— -220 —

-240—

II 45“) 00 II

Sheet 18 of 20 Nov. 29, 1983 4,417,459

l I l l l I

I0 20 30 4o 50 so 7'0 80 9'0 Bo

RELATIVE WALL THICKNESS ("/o)

STRAIN DISTRIBUTION OF THlCK-WALLED CYLINDER (CLOSED-END) AT I7" REVERSAL TO IOO ksI PRESSURE

FIGIS

US. Patent

STRESS, 5,09 ,0] ,0'2 , (ksi)

| .T. 0

NM ON 00 II

1 5 0

—I80

-2OO

~22O —240

Sheet 19 of 20 4,417,459 Nov. 29, 1983

|

50 6O 70 80/90 IOO

RELATIVE WALL THICKNESS ("/o)

STRESS DISTRIBUTION OF THICK-WALLED CYLINDER (CLOSED-END) AT I8’h REVERSAL TO ZERO PRESSURE

FIG.I9

autofrettage process

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