Sub-sized CVN specimen conversion methodology

Transcription

1 VTT TECHNICAL RESEARCH CENTRE OF FINLAND LTD C V Transition region Uper shelf "Ductile" Sub-sized CVN specimen conversion methodology Lower shelf "Brittle" T [ C] ASTM A1-13 meeting Tampa 215 Kim Wallin

2 ASTM A37 Table 9 6 KV ASTM A37 Table 9 Table 9 is based on a simple thickness-ratio correction /4 2/3 1/2 1/3 1/ /1/215 KV B 2

3 Subsized specimens Sub-size specimens yield higher absolute energies 1 8 1/1 2/3 1/2 A simple ratio-correction is not sufficient for the KV 5x1 6 4 adjustment of sub-size Charpy-V specimen energies KV 1x1 Sub-size specimens yield lower proportional energies

4 Effect of thickness on transition curve McNicol 1965 KV/(Bb) [J/cm 2 ] T [ o C] McNicol, R. (1965, September). Correlation of Charpy Test Results for Standard and Nonstandard Size Specimens. Welding Research Supplement, pp /1/215 4

5 Subsized specimens Sub-size specimens yield lower transition temperature TC V35J/cm 2 - TC V28J [ o C] 2 TC 95 % V28J = TC 2 V35J/cm ln{2 (B/1).25-1} T 5 C ASME UG-84.2 Towers 5 % THICKNESS CORRECTION FOR CVN TRANSITION TEMPERATURE B [mm] Similar to a statistical size effect related to cleavage initiation. See e.g. ASTM E1921. Included in BS Wallin K. Methodology for selecting Charpy toughness criteria for thin high strength steels - Part 1: Determining the fracture toughness: D733. Jernkontorets Forskning, 1994.

6 Subsized specimens Sub-size specimens yield lower transition temperature TC V35J/cm 2 - TC V28J [ o C] ASME UG-84.2 Towers 95 % 5 % TC V28J = TC V35J/cm ln{2 (B/1).25-1} T 5 C THICKNESS CORRECTION FOR CVN TRANSITION TEMPERATURE B [mm] Similar to a statistical size effect related to cleavage initiation. See e.g. ASTM E1921. Included in BS Wallin K. Methodology for selecting Charpy toughness criteria for thin high strength steels - Part 1: Determining the fracture toughness: D733. Jernkontorets Forskning, 1994.

7 Subsized specimens Sub-size specimens yield lower proportional upper shelf energies C VB-US /(Bb) [J/cm 2 ] mm 9 mm 8 mm 7.5 mm 7 mm 6.7 mm 6 mm 5 mm 4 mm 3.6 mm 3.3 mm 3 mm 2.5 mm s dcg s s Some shear and some flat fracture. Due to a competition between shear and flat fracture. All shear fracture C V1-US /.8 [J/cm 2 ] Wallin K Upper shelf energy normalisation for sub-sized Charpy-V specimens. Int J of Pressure Vessels and Piping, 78, 21, pp

8 Subsized specimens Sub-size specimens yield lower proportional upper shelf energies (C VB-US x1)/(c V1-US xb) All shear C V1-US /B [kn] Wallin K Upper shelf energy normalisation for sub-sized Charpy-V specimens. Int J of Pressure Vessels and Piping, 78, 21, pp

9 Subsized specimens Sub-size specimens yield lower proportional upper shelf energies Normalisation is insensitive to strength but sensitive to modulus of elasticity. Austenitic stainless slightly different than structural steel. Wallin K Upper shelf energy normalisation for sub-sized Charpy-V specimens. Int J of Pressure Vessels and Piping, 78, 21, pp

10 Subsized specimens Sub-size specimens yield lower proportional upper shelf energies 5 THICKNESS CORRECTION FOR UPPER SHELF KV 1 /.8 [J/cm 2 ] B = 7.5 mm B = 5 mm B = 3.3 mm B = 2.5 mm 1 Mean predictions KV B /(.8xB) [J/cm 2 ] Wallin K Upper shelf energy normalisation for sub-sized Charpy-V specimens. Int J of Pressure Vessels and Piping, 78, 21, pp

11 Temperature adjustment Energy conversion

12 The conversion accounts for the lower energy required to fracture shear lips. C V1-US corresponds basically to a value without shear lips. For high CVN energies the measured full size specimen energy becomes therefore less than indicated by the equation. Begins to effect when C V1 > 1 J.

13 Energy conversion 3 Estimated measured energy. KV KV 3/4 KV 2/3 KV 1/2 KV 1/3 KV 1/ KV B

14 16 14 McNicol 1965 KV 1est /(Bb) [J/cm 2 ] T adjusted [ o C] McNicol, R. (1965, September). Correlation of Charpy Test Results for Standard and Nonstandard Size Specimens. Welding Research Supplement, pp

15 low toughness KV 1est y 148 MPa T adjusted [ o C] Enrico Lucon, C. N. (215). Impact Characterization of 434 and T2 Steels by Means of Standard, Sub-Size and Miniaturized Charpy Specimens. NIST Technical Note 1858.

16 high toughness KV 1est y 952 MPa T adjusted [ o C] Enrico Lucon, C. N. (215). Impact Characterization of 434 and T2 Steels by Means of Standard, Sub-Size and Miniaturized Charpy Specimens. NIST Technical Note 1858.

17 3 25 T2 KV 1est y 1134 MPa T adjusted [ o C] Enrico Lucon, C. N. (215). Impact Characterization of 434 and T2 Steels by Means of Standard, Sub-Size and Miniaturized Charpy Specimens. NIST Technical Note 1858.

18 KV 1est X y 325 MPa T adjusted [ o C] E. Lucon, C. N. McCowan, and R. L. Santoyo, (215). Impact Characterization of Line Pipe Steels by Means of Standard, Sub-Size and Miniaturized Charpy Specimens. NIST Technical Note 1865.

19 5 KV 1est X y 514 MPa T adjusted [ o C] E. Lucon, C. N. McCowan, and R. L. Santoyo, (215). Impact Characterization of Line Pipe Steels by Means of Standard, Sub-Size and Miniaturized Charpy Specimens. NIST Technical Note 1865.

20 5 4 X7 KV 1est y 53 MPa T adjusted [ o C] E. Lucon, C. N. McCowan, and R. L. Santoyo, (215). Impact Characterization of Line Pipe Steels by Means of Standard, Sub-Size and Miniaturized Charpy Specimens. NIST Technical Note 1865.

21 KV 1est X1 y 817 MPa T adjusted [ o C] E. Lucon, C. N. McCowan, and R. L. Santoyo, (215). Impact Characterization of Line Pipe Steels by Means of Standard, Sub-Size and Miniaturized Charpy Specimens. NIST Technical Note 1865.

22 Upper shelf behaviour (KV B x1)/(kv 1 xb) L 434H T2 X52 X65 X7 X1 KV 1 > 4 J KV 1 /B [kn]

23 4 C V ISO ISO/DIN 3 r = 2 mm U <45MPa U =5-55MPa U =6-7MPa U >8MPa C VISO J ASTM C VASTM 3 J U = 8 MPa U = 45 MPa C 12 VASTM U r = 8 mm J MPa 4 2 The ASTM hammer show for high toughness higher energies than the ISO hammer C V ASTM E23

24 energy conversion Full size 3/4 2/3 1/2 1/3 1/ temperature adjustment Thickness Adjustment [ C] Full size 3/4 8 2/3 11 1/2 2 1/3 34 1/4 45

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