Impact toughness of the material is a crucial parameter in design of pressure vessels. Generally, at the option of the purchaser, Charpy V-notch impact test shall run for ASTM A516 (ASME SA-516) pressure vessel plates. The test shall be conducted in accordance with ASTM A370 and ASTM E-23. The simple-beam V-notch specimens shall be prepared sized of 10 mm(width) x 10 mm(thickness) x 55 mm(length). Three specimens for each heat lot shall be tested. The energy absorption of each specimen and average energy absorption for 3 specimens shall be recorded.

According to ASTM A20, ASTM A516 Gr. 55, Gr. 60, Gr. 65 plates are Class III steels which are killed with a specified minimum tensile strength of 65 ksi or lower. ASTM A516 Gr. 70 plates are Class IV steels which are killed with a specified minimum tensile strength of over 65 ksi to 75 ksi. The acceptance criteria of energy absorption are listed in below table.

Class & Grade	Minimum Average Energy Absorption for 3 Specimens, ft*lbf	Minimum Energy Absorption for 1 Specimen, ft*lbf
III: Gr. 55, 60, 65	13	10
IV: Gr. 70	15	12

*The materials shall be furnished in quenched and tempered condition.

Depending on different plate thicknesses t, the minimum test temperatures are also stipulated for each steel grade respectively.

ASTM A516	t ≤ 1"	1" < t ≤ 2"	2" < t ≤ 3"	3" < t ≤ 5"
Min. Temp. Grade 55	-60	-60	-50	-50
Min. Temp. Grade 60	-60	-50	-50	-50
Min. Temp. Grade 65	-60	-50	-40	-25
Min. Temp. Grade 70	-50	-40	-30	-20

*The minimum temperatures listed are for longitudinal tests. For transverse tests, it may be somewhat higher.