ASTM E28.04 Workshop

1
ASTM E28.04 Workshop

• Len Manning, Dofasco
• Affect of Proposed Changes on
• the Mechanical Properties of
• Low Carbon and HSLA Steels

2
Dofasco - Study Set Up

• Materials Used
• - Low C steel - 0.02 C, 0.30 Mn, 30ksi Yield
• - HSLA steel 0.06 C, 0.65 Mn, 0.02 Cb, 50 ksi
  Yield
• Sample Prep
• all tensile coupons of each material cut from one
  sample sheet.
• E8 Sheet type specimens prepared
• all pieces milled by the same operator, on the
  same milling center, at the same time.

3
Dofasco - Study Set Up

• Sample Testing
• Verification standards run before and after
  study pieces
• All specimen measurements conducted by one
  operator
• All tests conducted by one operator on the same
  day, using one test frame.
• Testing using the various speeds was conducted
  in random order.

4
Dofasco - Study Set Up

• Testing Speeds
• Three test speed set ups were used
• 0.16/min. until 5 strain, 1.00/min. until
  fracture
• Current lab practice
• 0.03/min. until 5 strain, 0.9/min. until
  fracture
• New E8 based on minimum parallel length
  specimen (2.25)
• 0.045/min. until 5 strain, 1.35/min until
  fracture
• New E8 based on 3 parallel length specimen

5
Dofasco - Low Carbon Steel
N 15 Current New E8-3 New E8-2 Diff.

Yield Average 29.34 28.84 28.72 0.62
(ksi) Stdev 0.447 0.477 0.636

Tensile Average 42.35 42.63 42.40 0.28
(ksi) Stdev 0.159 0.146 0.149

Elongation Average 45.31 44.77 45.56 0.79
() Stdev 1.120 0.691 1.077
6
Dofasco - HSLA Steel
N 15 Current New E8-3 New E8-2 Diff.

Yield Average 52.17 51.32 51.45 0.85
(ksi) Stdev 0.659 1.040 1.251

Tensile Average 68.87 68.98 68.63 0.35
(ksi) Stdev 0.395 0.430 0.635

Elongation Average 27.65 28.00 28.04 0.39
() Stdev 0.370 0.366 0.480
7
Dofasco - Low Carbon - Yield Strength - One-way
ANOVA

• Source DF SS MS F P
• Factor 2 3.213 1.606 5.79 0.006
• Error 42 11.658 0.278
• Total 44 14.871
• S 0.5269 R-Sq 21.60 R-Sq (adj.) 17.87
• Individual 95 CIs For
  Mean Based on
• Pooled StDev
• Level N Mean StDev --------------------
  ----------------
• YS-CU 15 29.339 0.447
  (----------------)
• YS-E3 15 28.839 0.477
  (----------------)
• YS-E2 15 28.724 0.636 (-----------------)
• 
  ------------------------------------
• 28.50
  28.80 29.10 29.40
• Pooled StDev 0.527

8
Dofasco - Low Carbon - Tensile Strength -
One-way ANOVA

• Source DF SS MS F P
• Factor 2 0.6534 0.3267 14.14 0.000
• Error 42 0.9702 0.0231
• Total 44 1.6236
• S 0.1520 R-Sq 40.25 R-Sq (adj.) 37.40
• Individual 95 CIs For
  Mean Based on
• Pooled StDev
• Level N Mean StDev --------------------
  ----------------
• TS-CU 15 42.353 0.160 (-----------)
• TS-E3 15 42.629 0.146
  (-----------)
• TS-E2 15 42.399 0.149 (-----------)
• 
  ------------------------------------
• 
  42.36 42.48 42.60 42.72
• Pooled StDev 0.152

9
Dofasco - Low Carbon - Elongation - One-way ANOVA

• Source DF SS MS F P
• Factor 2 4.925 2.462 2.55 0.090
• Error 42 40.499 0.964
• Total 44 45.424
• S 0.9820 R-Sq 10.84 R-Sq (adj.) 6.60
• Individual 95 CIs For
  Mean Based on
• Pooled StDev
• Level N Mean StDev -------------------
  -----------------
• EL-CU 15 45.317 1.120
  (-------------------)
• EL-E3 15 44.767 0.691 (------------------
  -)
• EL-E2 15 45.557 1.077
  (------------------)
• 
  ------------------------------------
• 
  44.50 45.00 45.50 46.00
• Pooled StDev 0.982

10
Dofasco - HSLA - Yield Strength - One-way ANOVA

• Source DF SS MS F P
• Factor 2 5.94 2.97 2.89 0.068
• Error 39 40.07 1.03
• Total 41 46.00
• S 1.014 R-Sq 12.91 R-Sq (adj.) 8.44
• Individual 95 CIs For
  Mean Based on
• Pooled StDev
• Level N Mean StDev ------------------
  ------------------
• YS-CU 14 52.174 0.659
  (-------------------)
• YS-E3 14 51.321 1.041 (-----------------
  ---)
• YS-E2 14 51.446 1.251
  (--------------------)
• 
  ------------------------------------
• 
  51.00 51.50 52.00 52.50
• Pooled StDev 1.014

11
Dofasco - HSLA - Tensile Strength - One-way ANOVA

• Source DF SS MS F P
• Factor 2 0.903 0.451 1.82 0.175
• Error 39 9.670 0.248
• Total 41 10.573
• S 0.4980 R-Sq 8.54 R-Sq (adj.) 3.85
• Individual 95 CIs For
  Mean Based on
• Pooled StDev
• Level N Mean StDev ------------------
  ------------------
• TS-CU 14 68.868 0.395
  (-------------------)
• TS-E3 14 68.982 0.430
  (-------------------)
• TS-E2 14 68.630 0.635 (-----------------
  ---)
• 
  ------------------------------------
• 
  68.50 68.75 69.00 69.25
• Pooled StDev 0.498

12
Dofasco - HSLA - Elongation - One-way ANOVA

• Source DF SS MS F P
• Factor 2 1.268 0.634 3.80 0.031
• Error 39 6.505 0.167
• Total 41 7.772
• S 0.4084 R-Sq 16.31 R-Sq (adj.) 12.02
• Individual 95 CIs
  For Mean Based on
• Pooled StDev
• Level N Mean StDev
  ------------------------------------
• Elong-CU 14 27.653 0.370 (----------------)
  
• Elong-E3 14 27.996 0.366
  (----------------)
• Elong-E2 14 28.042 0.480
  (----------------)
• 
  ------------------------------------
• 
  27.50 27.75 28.00 28.25
• Pooled StDev 0.408

13
Dofasco - Practical Implications for Production
Test Labs

• Lab Throughput, turn around time, equipment needs
• Product Specification Conformance checking
• Manufacturing Design capability

14
Dofasco - Average Values Against Initial Testing
Speed
15
Dofasco - Average Values Against Final Testing
Speed
16
Dofasco - Average Values Against Initial Testing
Speed
17
Dofasco - Average Values Against Final Testing
Speed
18
Dofasco - Summary

• Some statistical differences
• Little practical difference for production type
  labs
• May be a significant difference based on specific
  situations i.e. Research
• Significant affect on test time