ASTM E28.04 Workshop
Workshop on the
Speed of Testing
May 21, 2007
1
Norfolk, VA
Schedule of Presenters
Earl Ruth, Tinius Olsen
Jim Hartman, Honeywell
Carpenter Representative
Byron Skillings, Ladish
Len Manning, Dofasco
Sue Morford, Howmet
Rich Brazill, Alcoa
2
ASTM E28.04 Workshop
Ballot Item:
Revise ASTM E 8 Standard Test Methods for Tension Testing
of Metallic Materials by replacing existing section 7.6
Rationale:
For years the limitation on yield speed in E 8 has been in terms
of rate of stressing. The wide range of acceptable test speeds
currently in E 8 is another source of non reproducibility. This
change to E 8 attempts to simplify the speed of testing section,
make it more clear as to how to control today’s testing
machines, and improve the reproducibility of tests.
3
ASTM E28.04 Workshop
Earl Ruth, Tinius Olsen
Proposed Change to
Standard E8 Speed of Testing Section
4
Tinius Olsen - Changes to ASTM E8
Existing
Proposed

7.6.3 Speed of Testing When Determining Yield
Properties—Unless otherwise specified, any
convenient speed of testing may be used up to
one half the specified yield strength or up to one
quarter the specified tensile strength, whichever
is smaller. The speed above this point shall be
within the limits specified. If different speed
limitations are required for use in determining
yield strength, yield point elongation, tensile
strength, elongation, and reduction of area, they
should be stated in the product specifications. In
the absence of any specified limitations on speed
of testing, the following general rules shall
apply:

7.6.3 Speed of Testing When Determining Yield
Properties—Unless otherwise specified, the
following speeds shall apply. Any convenient
speed of testing may be used up to one half the
specified yield strength or up to one quarter of
the specified tensile strength, whichever is
smaller. The speed above this point shall be
within the limits specified. If different speed
limitations are required for use in determining
yield strength, yield point elongation, tensile
strength, elongation, and reduction of area, they
should be stated in the product specifications. In
the absence of any specified limitations on speed
of testing, the following rules shall apply:

7.6.3.1 The speed of testing shall be such that the
forces and strains used in obtaining the test
results are accurately indicated.

7.6.3.1 The speed of testing shall be such that the
forces and strains used in obtaining the test
results are accurately indicated.

7.6.3.2 When performing a test to determine
yield properties, the rate of stress application
shall be between 1.15 and 11.5 MPa/s


(10 000 and 100 000 psi/min).
7.6.3.2 When performing a test to determine
yield properties, the strain rate or the
crosshead speed shall be 0.00025 mm/mm/s
(0.015 inches/inch/min) +/- 20%.
5
Tinius Olsen - Test Matrix
 1 sheet steel specimen tested on
4 different testing machines at
6 different speed control settings
 4 Machines
• 5kN single screw machine w/ wedge grips
• 50 kN twin screw machine w/ wedge grips
• 300 kN Hydraulic machine w/ wedge grips
• 150 kN twin screw machine w/ hydraulic grips
6
Tinius Olsen -6 Pre-Yield
Test Speeds
• 1 – Existing E 8 Upper Limit using a position rate to achieve 100,000
psi/min
– (Position rate required varied with machine stiffness from 0.039 to 0.217 inches/min)
• 2 – Existing E 8 Lower Limit using a position rate to achieve 10,000
psi/min
– (Position rate required varied with machine stiffness from 0.004 to 0.025 inches/min)
• 3 – Existing E 8 Upper Limit using a strain rate of 0.0033 /min
– (Strain Rate corresponding to a Stress Rate of 100,000 psi per minute for steel with a
Modulus of Elasticity of 30X 106 psi)
• 4 – Existing A 370 Upper Limit using a position rate of 0.175 inches/min
– (ASTM A370 rate 1/16 of an inch per inch of reduced section per minute. Position rate of
0.175 in/min = 0.0625 /min X 2.8 inches)
• 5 – Proposed new rate using position control
– (Position rate of 0.042 in/min = 0.015 /min X 2.8 inches)
• 6 - Proposed new rate using strain rate control
7
– (0.015 /min)
Control
Type
Sample ID
CTRL/SPD
Ultimate (ksi)
OS @ .2 (ksi)
Time @ 0.2 Offset
(sec)
Stress Rate
Strain Rate
Position
Rate
1 Screw 5 kN
1
P 0.217
42.8
24
14.42
98000
0.0532
0.217
2 Screw 50 kN
1
P 0.140
42.2
23.3
27.3
107000
0.0399
0.1398
Super L 300 kN
1
P 0.16
42.7
23.4
21
109600
0.0431
0.1589
MHT 150 kN
1
P 0.039
42.1
22.8
23.9
96500
0.01286
0.0388
1 Screw 5 kN
2
P 0.025
42.5
22.3
117.9
10950
0.00627
0.0251
2 Screw 50 kN
2
P 0.0145
40.8
21.2
227
9390
0.00415
0.01448
Super L 300 kN
2
P 0.017
43.2
22.5
205
9940
0.00457
0.01705
MHT 150 kN
2
P 0.004
41.9
21.6
222
12460
0.001387
0.00415
1 Screw 5 kN
3
e 0.0033
42
21.9
51.6
61600
0.00327
0.01274
2 Screw 50 kN
3
e 0.0033
43.3
22.5
53.6
143600
0.00322
0.01142
Super L 300 kN
3
e 0.0033
42.6
22.2
55.4
99100
0.00326
0.01177
MHT 150 kN
3
e 0.0033
42
21.9
50.9
66800
0.00323
0.0097
1 Screw 5 kN
4
P 0.175
42.9
23.7
19.42
77200
0.0445
0.1749
2 Screw 50 kN
4
P 0.175
42.4
23.5
21.9
120500
0.0485
0.1751
Super L 300 kN
4
P 0.175
42.8
23.5
19.11
121000
0.0475
0.1752
MHT 150 kN
4
P 0.175
41.5
23.1
5.45
554000
0.0548
0.1772
1 Screw 5 kN
5
P 0.042
42.3
22.5
69.6
18740
0.01069
0.0421
2 Screw 50 kN
5
P 0.042
43.1
22.9
81.7
28800
0.01232
0.042
Super L 300 kN
5
P 0.042
43.4
23
83.4
26000
0.01171
0.0421
MHT 150 kN
5
P 0.042
41.8
22.6
22.6
106800
0.01352
0.0415
1 Screw 5 kN
6
e 0.015
42
23.3
13.55
162000
0.0168
0.0576
2 Screw 50 kN
6
e 0.015
42.8
22.9
13.09
435000
0.01491
0.0534
Super L 300 kN
6
e 0.015
42.4
22.7
15.53
584000
0.01481
0.0538
6
e 0.015
41.5
22.6
12.63
317000
0.01483
0.0499
MHT 150 kN
8
Tinius Olsen -Test Notes
 The Stress Rate was determined in the elastic
portion of the curve.
 The strain and position rates were determined
at the 0.2% Offset
9
Tinius Olsen - Stress Rate vs.
Strain Rate
O.2% Offset vs. Stress Rate
0.2% Offset vs. Strain Rate
24.5
24.5
24
24
23.5
23.5
23
23
22.5
22.5
22
22
21.5
21.5
21
21
0
100000 200000 300000 400000 500000 600000 700000
0.001
0.01
Stress Rate vs. Strain Rate
1000000
100000
10000
10
0
0.01
0.02
0.03
0.04
0.05
0.06
0.1
Tinius Olsen - Strain Rate
vs. Test Type
 1 – Existing E 8 Upper Limit
using a position rate to achieve
100,000 psi/min
Strain Rate vs. Test Type
 2 – Existing E 8 Lower Limit
using a position rate to achieve
10,000 psi/min
0.06
0.05
 3 – Existing E 8 Upper Limit
using a strain rate of 0.0033
/min
0.04
0.03
 4 – Existing A 370 Upper Limit
using a position rate of 0.175
inches/min
0.02
0.01
0
0
1
2
3
4
5
6
7
 5 – Proposed new rate using
position control at 0.042
inches/min
 6 - Proposed new rate using
strain rate control at 0.015 /min
11
Tinius Olsen - Effect on Yield
Strength
 1 – Existing E 8 Upper Limit
using a position rate to
achieve 100,000 psi/min
0.2% Offset vs. Test Type
 2 – Existing E 8 Lower Limit
using a position rate to
achieve 10,000 psi/min
24.5
24
 3 – Existing E 8 Upper Limit
using a strain rate of 0.0033
/min
23.5
23
22.5
 4 – Existing A 370 Upper
Limit using a position rate of
0.175 inches/min
22
21.5
21
0
1
12
2
3
4
5
6
7
 5 – Proposed new rate using
position control at 0.042
inches/min
 6 - Proposed new rate using
strain rate control at 0.015
/min
Tinius Olsen –
Production Considerations
 1 – Existing E 8 Upper Limit
using a position rate to
achieve 100,000 psi/min
Time to Offset vs. Test Type
 2 – Existing E 8 Lower Limit
using a position rate to
achieve 10,000 psi/min
250
200
 3 – Existing E 8 Upper Limit
using a strain rate of 0.0033
/min
150
100
50
0
0
1
2
3
4
5
6
7
 4 – Existing A 370 Upper
Limit using a position rate of
0.175 inches/min
 5 – Proposed new rate using
position control at 0.042
inches/min
13
 6 - Proposed new rate using
strain rate control at 0.015
/min
Tinius Olsen - Conclusions
 We should be able to reduce interlaboratory scatter by specifying the
default ASTM E 8 speed in terms of Strain Rate instead of Stress
Rate.
 We can get comparable results by controlling the test in position rate
or strain rate.
 ASTM A370 speed of 1/16 of an inch per inch of reduced section is
too fast for some machines.
 Controlling position rate to achieve a 0.005 /min strain rate (popular
in many aerospace specifications) makes for a very long test time.
 A strain rate of 0.015 /min which allows both position control and
strain rate control is reasonable because it can be achieved on
machines without closed-loop strain rate control, there is good
agreement between the position rate and the strain rate, and
production testing is not harshly impacted.
14