Technical conditions for plates of A517GrQ Modified
1. Scope
The technical conditions apply to plates of A517GrQ Modified with thickness not less than 60mm. (60mm-254mm)
2. Adopt standard:
ASTM A517/A517M Standard Specification for Pressure Vessel Plates, Alloy Steel, High-Strength, Quenched and Tempered
ASTM A20/A20M Standard Specification for General Requirements for Steel Plates for Pressure Vessels
ASTM A370 Standard Test Methods and Definitions for Mechanical Testing of Steel Products
3. Dimension, Shape, Weight and Permissible Deviation
The dimension, shape, weight and permissible deviation shall meet the requirements of ASTM A20/A20M.
Thickness tolerance: -0.5~+3.5mm
Flatness: 4mm/m
Surface shot blasting or peeled.
4. Technical conditions
4.1 Chemical composition (Ladle analysis)
The chemical composition of plates shall be accordance with the following table 1.
Table 1 Chemical composition (Ladle analysis)
C | Si | Mn | P | S | Cr | Ni | Mo | Alt | Nb | V | Ti |
Max 0.18 | 0.15- 0.35 | 0.95- 1.3 | Max 0.035 | Max 0.010 | 1.00- 1.50 | 1.20- 1.50 | 0.40- 0.60 | Min 0.020 | Max 0.050 | 0.03- 0.08 | Max 0.020 |
Note: Nb+V+Ti =<0.12%
4.2 Steel making process: EAF+LF/VD
4.3 Carbon equivalent (CEq)
Carbon equivalent shall be calculated as follows:
CEq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15 (%)
4.4 Tensile properties
The tensile properties of A517GrQ Modified shall meet the requirement as table 2.
Table 2 Tensile properties
Thickness mm | Yield strength MPa | Tensile strength MPa | Elongation % |
80-100 | Min 690 | 790-930 | Min 14 |
4.5 Impact properties
Impact test in the longitudinal and transverse for plates of A517GrQ Modified shall meet the requirements per table 3.
Table 3 Impact properties
Charpy-V Impact test Test temp. Celsius degree | Longitudinal 1/4 Thickness | Longitudinal 1/2 Thickness | ||
Average impact energy | Average impact energy | |||
-37C | Min 69J | -27C | Min 69J | |
4.6 Grain size
Grain size for plates shall be according to A517GrQ.
4.7 Surface quality
The surface quality of plates shall be accordance with ASTM A20/A20M.
4.8 Ultrasonic inspection
Plates shall be ultrasonic inspected per ASTM A578/A578M level C.
4.9 Test method and inspection rules
Test items, sampling quantity, sampling method and test method shall conform to table 4.
Table 4 Test items for plates
No. | Test item | Quantity, Piece | Direction | Test menthod |
1 | Product analysis | 1 (per heat treatment pc) | / | According to ASTM A370 |
2 | Tensile test | 1 (per heat treatment pc) | Transverse | |
3 | Charpy-V impact test at -40C | 3 (per heat treatment pc) | Transverse | |
4 | 3 (per heat treatment pc) | Longitudinal |
5. Package, marking and certificate
Package, marking and certificate shall conform to A20.
6. The third party inspection
The chemical composition, tensile test and Charpy -V impact test for plates of A517GrQ Modified shall be witnessed by surveyor of ABS.
7. Delivery conditions
The delivery conditions for plates of A517GrQ Modified shall be Quenching +Tempering.
8. Other requirements
The other requirements for plates of A517GrQ Modified shall be accordance with A517GrQ.
MTC accordance with EN10204: 2004 3.2
