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AD-A268 355 8 0 /C
Atlas of Formability;'
Haynes 188,
EECTEA G1819931J .
NCEM
DISCLAIIMI K6TICE
THIS DOCUMENT IS BEST
QUALITY AVAILABLE. THE COPY
FURNISHED TO DTIC CONTAINED
A SIGNIFICANT NUMBER OF
PAGES WHICH DO NOT
REPRODUCE LEGIBLY.
ATLAS OF FORMABILITY
HAYNES 188
by
Prabir K. Chaudhury and Dan Zhao
National Center for Excellence in Metalworking Technology1450 Scalp Avenue
Johnstown, PA 15904
for
Naval Industrial Resource Support ActivityBuilding 75-2, Naval Base
Philadelphia, PA 19112-5078
February 28, 1993
The views, opinions, and/or findings contained in this report are those of the authors and should not be
construed as an official Department of the Navy position, policy, or decision, unless so designated by
other documentation
j Form ApprovedREPORT DOCUMENTATION PAGE IOM No. o7o4-01
Puobic leoortlIng burden for this collection of information is estimated to average I hour oer resporse. including the time for reviewing instructions. searchting existing data so!urc•,gather.ng and maintaining the data needed, and comtletilng and reviewng tne callection of information send comments regarding this burden estimate or any Othe a..en of this
collectoon of information. including suggestions for reducing this Ouroen. to Washington Headduarters Services. Directorate for information Operations and Report%. 1215 jeffersonDavis Higt'wav. Suite 1204. Arlington. VA 22202-4302. and to the Office of Management and Budget. Paperwork Reduction Project (0?04-0 188). Washington. DC 20503.
"1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVEREDFebruary 28, 1993 Final, Nov. 30, 1992 - Feb. 28, 1993
4. TITLE AND SUBTITLE S. FUNDING NUMBERS
ATLAS OF FORMABILITY C-N00140-88-C-RC21HAYNES 188
6. AUTHOR(S)
Prabir K. ChaudhuryDan Zhao
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATIONREPORT NUMBER
National Center for Excellence in Metalworking Technology (NCEMT)1450 Scalp AvenueJohnstown, PA 15904
9. SPONSORING,' MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/ MONITORING
AGENCY REPORT NUMBER
Naval Industrial Resources Support ActivityBuilding 75-2, Naval BasePhiladelphia, PA 19112-5078
11. SUPPLEMENTARY NOTES
1Za. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE
13. ABSTRACT (Maximum 200 words)
In this investigation, flow behavior of Haynes 188 alloy was studied by conducting compression testsover a wide range of temperatures (950 - 1200 C) and strain rates (0.001 - 20 s-1 ). The true stress-truestrain flow curves are presented for each test condition. Constitutive relations were determined from theflow behavior, and a dynamic material modeling was performed on this alloy. Thus, the optimumprocessing condition in terms of temperature and strain rate was identified as 1100 C and 0.001 s- 1 forthis alloy. Microstructural changes during high temperature deformation were also characterized, andselective micrographs are presented together with corresponding flow curves. Dynamic recrystallizationand grain growth occurred during high temperature deformation over the range of temperatures tested.This report supplies ample mechanical and microstructural data on Haynes 188 alloy for engineers inthe field of metalworking process design. The data presented here are also very helpful in finite elementanalysis of metalworking processes.
14. SUBJECT TERMS 15. NUMBER OF PAGES
Haynes 188, Deformation Processing, High Temperature Deformation, 16. pEt CODEProcessing Map, Metalworking, Deformed Microstructure
17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACrOF REPORT OF THIS PAGE OF ABSTRACT
Unclassified Unclassified UnclassifiedNSN 7540-01-280-5500 Standard Form 298 (Rev 2-89f
P-ý:p ? NS, z3 .39-8i.1 i- 1
TABLE OF CONTENTS
Introduction ................................... 1
Experimental Procedure ............................ 1
Results ....................... ............... 1
Summary .................................... 64
Implementation of Data Provided by the Atlas of Formability ........ 64
Aooession For
OTIS GRA&I EKDTIC TAB DUnannounced oJustificatlon
ST #A, AUTH USNAVIRSA (MR PLONSKY 8/443-6684) By
PER TELECON, 17 AUG 93 CB itributi on/
Availability Codesnnlt Avail and/or---Dlt special
LIST OF TABLE
Table 1. List of figures, testing conditions and microstructural observationsfor Haynes 188 ....... ................................. 2
fi
Haynes 188
Introduction
Haynes 188 alloy combines excellent high temperature strength with very good resistance tooxidizing environments up to 1095 C. The alloy also has good forming and welding characteristics,but work-hardens rapidly. The understanding of mechanical and microstructural behavior during hightemperature deformation is very important for the forming processes of this material. In thisinvestigation, flow behavior of Haynes 188 was studied by conducting compression tests over a widerange of temperatures and strain rates. Constitutive relations were determined from the flow behaviorand subsequently, a dynamic material modeling for this alloy was performed. Thus, the optimumprocessing condition in terms of temperature and strain rate was determined. Microstructural changesduring high temperature deformation were also characterized to help process design engineers selectprocessing conditions for desired microstructure.
Experimental Procedure
The material used in this investigation was commercially available Haynes 188 wrought bars inannealed condition with approximately 16 mm diameter. The typical microstructure of the as-receivedmaterial is shown in Figure 1. The chemical composition is as follows (wt%, bal. Co):
C S Mn Si Cr B Fe Ni W P
0.11 <0.002 0.78 0.41 22.04 0.004 2.20 22.67 13.81 0.014
Cylindrical compression test specimens with a diameter of 12.7 mm and a height of 15.9 mmwere machined from the bars. Isothermal compression tests were conducted in vacuum on an MTStesting machine. The test matrix was as follows:
Temperature, C (F): 950 (1742), 1000 (1832), 1050 (1922), 1100 (2012), 1150 (2102), 1175(2147), and 1200 (2192);
Strain rate, s-1: 0.001, 0.01, 0.05, 0.1, 0.5, 1, 5 and 20.
Load and stroke data were acquired during the tests by a computer and later converted to truestress-true strain curves. Immediately after the compression test, the specimens were quenched withforced helium gas in order to retain the deformed microstructure. Longitudinal sections of thespecimens were examined by optical microscopy. The photomicrographs were taken from the centerof the longitudinal section of the specimens.
Results
Table 1 is a list of the figures, test conditions, and the observed microstructures. The truestress-true strain flow curves with selective corresponding deformed microstructure are shown inFigure 2 to Figure 57. True stress versus strain rate was plotted in log-log scale in Figure 58 at a truestrain of 0.5. The slope of the plot gives the strain rate sensitivity m, which is not constant over therange of temperatures and strain rates tested. Log stress vs. I/T at the same true strain is shown inFigure 59. A processing map at this strain was developed and is shown in Figure 60. The optimumprocessing condition from the map can be obtained by selecting the temperature and strain ratecombination which provides the maximum efficiency in the stable region. This condition isapproximately 1100 C and 10-3 s- 1 for this material.
I
Table 1. List of figures, testing conditions and microstructural observations for Haynes 188.
Figure Temperature Strain Rate Microstructure PageNo C (F) s-I No
Optical MicroscopyI As received Equiaxed grains with an average size of 54.4 gun, 4
multiple twins in some grains and presence ofprecipitates.
2 950(1742) 0.001 Deformed grains with an average size of 59 m, 5-30% dynamically recoystallized (DRX) grains with<2 jum in size surrounding the large deformedgrains, presence of fine precipitates.
3 950(1742) 0.01 64 950 (1742) 0.05 Same as above, but with some twins. 75 950(1742) 0.1 Elongated grains with an average size of 55.3 un, 8
-20% recrystallized grains with < 2 min in size.6 950 (1742) 0.5 97 950(1742) 1 Severely deformed grains with - 5001 DRX grains 10
(<2 pm in size) and some neckacing at the grainboundaries.
8 950(1742) 5 119 950(1742) 20 Same as above, but with less amount of 12
rectystallized grains (-10%) and presence ofsubstructure.
10 1000(1882) 0.001 Deformed grains with serrated boundaries and 13-100% substructure formation.
11 1000(1882) 0.01 Same as above but with less substructure formation. 1412 1000(1882) 0.05 1513 1000(1882) 0.1 1614 1000(1882) 0.5 Severely deformed grains with -80% DRX (< 4 pm 17
grain size) presence of deformed original grainboundaries.
15 1000 (1882) 1 Same as above. 1816 1000(1882) 5 1917 1000(1882) 20 Same as above but with -60% DRX 2018 1050 (1922) 0.001 -90% DRX (-8 pam grain size), the deformed 21
original grain boundaries hardly visible.19 1050(1922) 0.01 2220 1050(1922) 0.05 Large severely deformed grains with -80% DRX, 23
presence of defonned origiani grain boundaries.21 1050 (1922) 0.1 2422 1050 (1922) 0.5 2523 1050(1922) 1 Same as above, but with less amount of DRX 2624 1050(1922) 5 Same as above. 2725 1050(1922) 20 Same as above. 2826 1100(1212) 0.001 100% DRX equiaxed grains (average grain size of 29
8.2 * 0.9 jim).27 1100(1212) 0.01 Same as above, but with a larger grain size. 3028 1100(1212) 0.05 3129 1100(1212) 0.1 100% DRX equiaxed grains (7.7 :k 0.7 jam in size) 32
within the large deformed originalgrains.30 1100(1212) 0.5 1 3331 1100(1212) 1 -So0. DRX grains (-6.5 pmn in size) within the 34
large deformed grains, some substructure formation.
2
32 1100(1212) 5 3533 1100(1212) 20 100% DRX equiaxed grains (-6.1 p&m in size) 36
within the sverl deformed s34 1150(2102) 0.001 100% DRX grains (-40 ;un in size), some multiple 37
twins and evenly dispersed fine precipitates.35 1150(2102) 0.01 Same as above, but with-25 Mn DRX grains. 3836 1150(2102) 0.05 3937 1150(2102) 0.1 4038 1150(2102) 0.5 100% equiaxed unirorm sized grains with no 41
evidence of prior grain boundaries.39 1150(2102) 1 Same as above but with-15 jAm DRX grain size. 4240 1150(2102) 5 4341 1150(2102) 20 Same as above, but with -10 tun in grain size and 44
some twinning.42 1175(2147) 0.001 100% DRX and grown grains with -55 Pn in size, 45
some multiple twinning and evenly distributed fineprecipitates.
43 1175 (2147) 0.01 4644 1175(2147) 0.05 Same as above, but with -20 jin grain size. 4745 1175 (2147) 0.1 4846 1175 (2147) 0.5 4947 1175 (2147) 1 100% DRX with non-uniform sized grains (average 50
-15 run), multiple twins in some grains and evenlydistributed fine precipitates.
48 1175 (2147) 5 Same as above with more regular grain size. 5149 1175 (2147) 20 Same as above with even more uniformly sized 52
owrains.50 1200 (2192) 0.001 100% DRX and grown equiaxed grain with an 53
average size of 67.6 * 15.7 lun, multiple twins insome grains and considerably less amount of fineprecipitates.
51 1200 (2192) 0.01 Same as above, but with smaller (-40 Pam) DRX 54grain size.
52 1200(2192) 0.05 5553 1200 (2192) 0.1 100% DRX and grown non-uniform sized grains 5654 1200(2192) 05 (average -30.5 + 3.4 pam) with much twinning. 5754 1200 (2192) 0.5 _______ _________57
55 1200(2192) 1 Same as above with - 30 Pin grain size. 5856 1200 (2192) 5 5957 1200(2192) 20 Same as above with - 26* 1.9 ýn grain size. 60
3
Figure 1. As-received mnicrostructure, of Haynes 188.
300, ,
Haynes 1 88
250
o_ 200
U)1 50
L_
: 100I-
50 Temperature: 950 CStrain Rate: 0.001 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501m
Figure 2. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 950 C and 0.001 s-1I
5
4-50
Haynes 1 88
,__ 350
Ci 250Q)
4-1-
• 1501--
Temperature: 950 C50 Strain Rate: 0.01 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 3. True stress-true strain curve, 950 C and 0.01 s- 1.
6
500, ,
Haynes 1 88
400
0a
v- 300U)4-0
o 200
100 Temperature: 950 C
Strain Rote: 0.05 --1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 4. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 950 C and 0.05 s-1.
7
600 , ,
Haynes 1 88500
a 400
CO
Q 300L.
4a
(n)(D 200
I--
100 Temperature: 950 CStrain Rate: 0.1 a-1
0 * I I 1 I I , I * I * I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 5. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 950 C and 0. 1 s-
8
700 , ,
Haynes 188600
500
400 -
2! 300
=30
2001
100 Temperature: 950 CStrain Rate: 0.5 a- 1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 6. True stress-true strain curve, 950 C and 0.5 s-1.
9
700 , ,
Hoynes 1 88600
o' 5000_
, 400CO
-b 300
i.- 200
10O0 Temperature: 950 CStrain Rate: 1.0 3-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 7. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 950 C and I s-1
10
K,'Lp- 7.00
Haynes 1 88600
500r•
S400
-- 300
L- 200
100 Temperature: 950 CStrain Rate: 5.0 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 8. True stress-true strain curve, 950 C and 5 s-1.
II
800 , , , , ,700 Haynes 188700
,, 600
M 500
2 400
S30oo
I- 200
100 -Temperature: 950 C
Strain Rate: 20.0 s-1
0I I * I , I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 9. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 950 C and 20 s-1.
12
300 , , •Haynes 1 88
250
o_ 200
CO'S 150
100 0
50 Temperature: 1000 CStrain Rate: 0.001 3-1
00.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 10. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1000 C and 0.001 s- 1.
13
"400
Haynes 188
320
240
U) 160
1,..
80 Temperature: 1000 C
Strain Rate: 0.01 sr-
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501Lm
Figure 11. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1000 C and 0.01 s-1.
14
500
Haynes 1 88
400
C-*v 300(nU,D
L.t
U) 200
1.~
100 Temperature: 1000 C
Strain Rate: 0.05 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 12. True stress-true strain curve, 1000 C and 0.05 s-1.
15
500
Hoynes 1 88
400
•-' 300CD
UA 200
100 Temperature: 1000 C
Strain Rote: 0.1 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 13. True stress-true strain curve, 1000 C and 0. 1 s'1.
16
600Haynes 188
500
Q- 400
(D 300
S 200
100 Temperature: 1000 CStrain Rate: 0.5 a-1
0 1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 14. True stress-true strain curve and an optical mnicrograph from the center of the compressed
sample cut through the compression axis, 1000 C and 0.5 s-1 .
17
600 , ,
Haynes 188
500I:,,
- 400 0
p 300
S200
100 Temperature: 1000 CStrain Rate: 1.0 3-1
O0 o 1, , , I0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501Lm
Figure 15. True stress-true strain curve and an optical micrograph from the center of the compressed
sample cut through the compression axis, 1000 C and I s-1 .
18
600 , , , , , ,
Haynes 188500
CL 400
Co(D 300L.
4-0-
3 200
100 Temperature: 1000 CStrain Rate: 5.0 a-1
O0 1 .- I . - I I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 16. True stress-true strain curve, 1000 C and 5 s-.
19
800 , ,
7 Hoynes 1 88700-
600CL
S500
( 400L.
03 300
•- 200Temperature: 1000 C
10 Stroin Rate: 20.0 s1
00.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 17. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1000 C and 20 s-1.
20
200 , , , .
Haynes 1 88
1500~
Cn
n 100
I-..- 50
Temperature: 1 050 CStrain Rate: 0.001 s-1
0 1 . I ., I ,
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 18. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1050 C and 0.001 s"1.
21
300Haynes 1 88
250
0 20 200
Q 150L.
=3 100
50 Temperature: 1 050 CStrain Rate: 0.01 s1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 19. True stress-true strain curve, 1050 C and 0.01 s-1.
22
Haynes 188
S300
• 200L.o
Cl)
P- 100Temperature: 1050 CStrain Rate: 0.05 s-1
0 J I * I * I p I , * I I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 20. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1050 C and 0.05 s-.
23
400 , ,
Haynes 1 88
,- 3000 2
(DG'3< 200
-I-
I-100
Temperature: 1050 CStrain Rate: 0.1 s-1
0. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 21. True stress-true strain curve, 1050 C and 0.1 s-1.
24
500Haynes 1 88
400
- 300C/3
S200
1.~
100 Temperature: 1 050 C
Strain Rate: 0.5 a-1O0 1 1 . -I , .
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 22. True stress-true strain curve, 1050 C and 0.5 s-1.
25
500 , ,
Haynes 188
400
300
L.
200
0)O
100 Temperature: 1050 C
Strain Rate: 1 .0 a-1
0 1 - . I . I I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 23. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1050 C and I s-1.
26
600 *
.Haynes 1 88500
~- 400
D 2300L-4
S200
100 -Temperature: 10500CStrain Rate: 5.0 s-1
00.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 24. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut throughi the compression axis, 1050 C and 5 s-1.
27
700 0 , , ,Haynes 1 88
600
500
u 400
S300
L- 200
1Temperature: 1050 C100 Strain Rate: 20.0 s-1
O0 1 1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
5%Lm
Figure 25. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1050 C and 20 s-1.
28
150
Haynes 1 88
120
S 90U3
L. 1) 601=I3
30 Temperature: 1100 CStrain Rate: 0.001 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501m
Figure 26. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1100 C and 0.001 s-1 .
29
200 , ,
Haynes 1 88
150
Q 100
I- 50Temperature: 1100 CStrain Rate: 0.01 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501Pm
Figure 27. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1100 C and 0.01 s- 1.
30
300Haynes 1 88
250 -
o_ 200
U3@ 150L.
100 0
50 Temperature: 1100 CStrain Rate: 0.05 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 28. True stress-true strain curve, 1100 C and 0.05 s-1.
31
300 , . ,Hoynes 1 88
250
o_ 200
< 150
:31 00
50 Temperature: 1100 CStrain Rate: 0.1 a-1
O0 1 1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501Lm
Figure 29. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1100 C and 0. 1 s'-
32
400 0 *
Haynes 188
300
q 200
I- 100
Temperature: 1100 CStrain Rate: 0.5 a-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 30. True stress-true strain curve, 100 C and 0.5 s-1 .
33
400 , *
Haynes 1 88
300a-
(D 200L.
:3)
I- 100
Temperature: 1100 CStrain Rate: 1.0 s-1
O0 1 1 1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501zm
Figure 3 1. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1100 C and I s-1.
34
500 , ,
Haynes 1 88
400
300
200
100 Temperature: 1100 C
Struin Rate: 5.0 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Figure 32. True stress-true strain curve, 1100 C and 5 s-1.
35
600Hoynes 1 88
500
. 4-00
q) 300
S200
100 Temperature: 1100 CStrain Rate: 20.0 s-I
00.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 33. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1100 C and 20 s".
36
100 *
.Hoynes 188
80
*•-' 60U]Uf)
40
20 Temperature: 1150 C
Strai• Rate: 0.001 s-1
O0 1 1 1 . I I ,
00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
5N
Figure 34. True stress-true strain curve and an optical micrograph from the center of the compressed
sample cut through the compression axis, 1150 C and 0.001 s-1.37
Haynes 1 88
120
90 ' 9
L.
60
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 3 5. True stress-true strain curve and an optical midcrograph from the center of the compressedsample cut through the compression axis, 1150 C and 0. 01 s-.
38
200 ..
Haynes 188
"150
ff 100
(')
50Temperature: 1150 CStrain Rate: 0.05 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 36. True stress-true strain curve, 1150 C and 0.05 s-1.
39
250 , ,
Haynes 188
200
%-,150cn
S1oo0
50 Temperature: 11 50 C
Stroan Rote: 0.1 a-100 . , , , , ,. --I . I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 37. True stress-true strain curve, 1150 C and 0.1 S-1.
40
300 , ,
Hoynes 188250
o_ 200
CnS 150
L.
:3 100I-
50 Temperature: 1150 CStruin Rate: 0.5 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501Lm
Figure 38. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1150 C and 0.5 s-1.
41
400Haynes 1 88
300
S200t-I
LF- 100Temperature: 1150 CStrain Rate: 1.0 a-0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501L
Figure 39. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1150 C and 1 s 1.
42
4.00 0 ,
Haynes 1 88
'-, 300
QC-
p, 200U-
0):3
•- 100Temperature: 1150 CStrain Rate: 5.0 a-'
0 L0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 40. True stress-true strain curve, 1150 C and 5 s-.
43
500
Haynes 188
400
0300
U3
CD
200
100 Temperature: 1150 C
Strain Rote: 20.0 s-1
0 l l 1 I I l l I - . I I I0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 41. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1150 C and 20 s.
44
100 *
Hoynes 188
80
%-.' 60
44-0
20STemperature: 1 175 CStrain Rate: 0.001 s-1
00 , 1 , -,. , . , . I I00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
5%L
Figure 42. True stres-tre strain curve and an optical micrograph from the center of the compressedsample cut 20 roug the compression aCis, 1175 C and 0.0011 s-
45
150
Haynes 188
120O
a-S90
CD,
,4-, 60
L.I--
30 Temperature: 11 75 CStrain Rate: 0.01 s-1
o f -I- I . -I . . I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 43. True stress-true strain curve, 1175 C and 0.01 s-I.
46
200
Haynes 1 88
500- 5
Temperature: 11 75 CStrain Rate: D.05 s-I
0 101
0.0• 0.1 0.2 0.3 0.4 0.5 0,6 0.7 0.8
True Strain
Figure 44. True stress-true strain cure and an optical micrograph from the center of the compressedsample cut through the compression axis, 1175 C and 0.05 $-1.
47
0 *II iii I III i I * 1 ii
200 , ,
Haynes 1 88
"• 1500~CL
U3
e 100
C")=3
S- 50Temperature: 1175 C
Strain Rate: 0.1 a-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 45. True stress-true strain curve, 1175 C and 0.1 s- 1.
48
300 , ,
Hoynes 1 88250
0
oL 200
W 150
U)G> 100
50 Temperature: 1175 CStrain Rote: 0.5 sa1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 46. True stress-true strain curve, 1175 C and 0.5 s-1.
49
300Hoynes 1 88
250
a- 200
1•50U)V 1 O0
S 100
50 Temperature: 1175 CStrain Rote: 1 .0 a-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
50p1m
Figure 47. True stress-true grain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1175 C and I s-1.
50
400 * *
Haynes 1 88
S' 300
0~=3
S200
I- 100Temperature: 1175 CStrain Rate: 5.0 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501•m
Figure 48. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1175 C and 5 s-1.
51
4-00
Haynes 1 88
,'-, 300
Q 200
L_
S100 -
Temperature: 1175 CStrain Rate: 20.0 3-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 49. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1175 C and 20 s-1.
52
80 * *
Haynes 1 88
60
• 40
20
Temperature: 1200 CStrain Rate: 0.001 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
!501Lm
Figure 50. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1200 C and 0.001 s 1 .
53
150 *
.Haynes 188
120
9000n
U) 6
30 Temperature: 1200 C
Strain Rate: 0.01 w-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 5 1. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1200 and 0.01 s-1.
54
150 , . ,
Haynes 1 88
120
• 90
C) 601.!
30 Temperature: 1200 C
Strmin Rate: 0.05 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 52. True stress-true strain curve, 1200 C and 0.05 s-1.
55
200 , ,
Haynes 1 88
150
:35 00
Temperature: 1 200 CStrain Rate: 0.1 a-1
00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
-I-I
Figure 53. True stress-true strain curve and an optical micrograph from the center of the compressedsample cut through the compression axis, 1200 and T. 1 s-1.
56
300Haynes 1 88
250
0._ 200
g 150
100 0
50 Temperature: 1200 CStrain Rate: 0.5 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 54. True stress-true strain curve, 1200 and 0.5 s-1 .
57
300i. Haynes 1 88
250
C- 200
E 150,4-,
UI)
:3 1001
50 Temperature: 1200 CStrain Rate: 1 .0 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
501•m
Figure 55. True stress-true strain curve and an optical micrograph from the center of the compressed
sample cut through the compression axis, 1200 and 1 s-
58
400 , , '
Haynes 1 88
300
200
100Temperature: 1200 CStrain Rote: 5.0 a-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Figure 56. True stress-true strain curve, 1200 and 5 s-1.
59
400 . . .
Haynes 1 88
•-' 300
Q 200L.
-4-P
I- 100
Temperature: 1200 CStrain Rate: 20.0 s-1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
True Strain
Figure 57. True stress-true strain curve and an optical micrograph from the center of the compressed
sample cut through the compression axis, 1200 and 20 s-1.
60
103
Haynes188
A
CL AC80 U AA"a. A U 100A
13 Temperature (C)_• 102 A v0) 950
a Q , 1000:3 1050
0 1100A 1150o 1175v 1200
101 a a kIIII a .10-3 10-2 10-1 100 101
Strain Rate (s-1)
Figure 58. Effect of strain rate on stress in log-log scale at a true strain of 0.5 for Haynes 188.
61
1 03
Haynes 188
9A
Q0 0Av v
3 A
D 102 * Strain Rate (a-')-~~ AA
CI) * 0.001• * A 0.01
M 0.05
+ 0.5* 1.0v 5.00 20.0
101 I i ,/i(, n , /K, 0.1
0.65 0.68 0.72 0.75 0.78 0.82 0.851/ b(1 O00/K)
Figure 59. Effect of temperature on stress at a true strain of 0.5 for Haynes 188.
62
Haynes 1 88
0
30.
C,)
O -2-j
950 1000 1050 1100 1150 1200Temperature (C)
Figure 60. Processing mnap of Haynes 188 at a true strain of 0.5.
63
Summary
Compression tests have been performed on Haynes 188 over a wide range of temperatures andstrain rates. The experimental conditions used in this work are representative of those inmetalworking practice. From the true stress-true strain curves, the flow behavior was characterizedand a processing map indicating the optimum processing condition was generated. This condition is1100 C and 10-3 s-1 .
The deformed microstructures were characterized from the quenched specimens by opticalmicroscopy and are presented for selective testing conditions together with the stress-strain curves.
Implementation of Data Provided by the Atlas of Formability
The Atlas of Formability program provides ample data on flow behavior of various importantengineering materials in the temperature and strain rate regime commonly used in metalworkingprocesses. The data are valuable in design and problem solving in metalworking processes ofadvanced materials. Microstructural changes with temperature and strain rates are also provided inthe Bulletin, which helps the design engineer to select processing parameters leading to the desiredmicrostructure.
The data can also be used to construct processing maps using the dynamic material modelingapproach to determine stable and unstable regions in terms of temperature and strain rate. Thetemperature and strain rate combination at the highest efficiency in the stable region provides theoptimum processing condition. A processing map has been developed in this Bulletin. In somemetalworking processes, such as forging, strain rate varies within the workpiece. An analysis of theprocess with finite element method (FEM) can ensure that the strain rates at the processingtemperature in the whole workpiece fall into the stable regions in the processing map. Furthermore,FEM analysis with the data from the Atlas of Formability can be coupled with fracture criteria topredict defect formation in metalworking processes.
The data provided by the Atlas of Formability are used in the design of metalworkingprocesses, dynamic material modeling, FEM analysis of metalworking processes, and defect predictionat Concurrent Technologies Corporation. CTC can apply its expertise in metalworking area to solverelated problems. For more information, please contact Dr. Prabir K. Chaudhury, Manager ofForming Department, by calling (814) 269-2594.
64