Technical conditions for plates of X7Ni9
1. Scope
The technical conditions apply to plates of X7Ni9 with thickness not more than 50mm. (8mm-50mm)
2. Adopt standard:
BS EN10028-4 Flat products made of steels for pressure purposes-Nickel alloy steels with specified low temperature properties.
3. Dimension, Shape, Weight and Permissible Deviation
The dimension, shape, weight and permissible deviation shall meet the requirements of EN10029.
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 | Alt | Mo | V | Ni |
Max 0.10 | Max 0.35 | 0.30- 0.80 | Max 0.010 | Max 0.004 | Min 0.02 | Max 0.10 | Max 0.01 | 8.5- 10.0 |
Note: Ni+Cu+Mo =<0.50%
4.2 Mechanical properties
The mechanical properties of X7Ni9 shall meet the requirement as table 2.
Table 2 Tensile properties
Thickness mm | Yield strength MPa | Tensile strength MPa | -196 C Akv (J) Transverse | Elongation % | Bend test 180C |
8-30 | Min 575 | 680-820 | Min 100J | Min 18 | d=3a |
31-50 | Min 565 | 680-820 | Min 100J | Min 18 | d=3a |
4.3 Surface quality
The surface quality of plates shall be accordance with EN10163-2.
4.4 Ultrasonic inspection
Plates shall be ultrasonic inspected per EN10160-1999 S2E2.
4.5 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 | Sampling method | Test method |
1 | Chemical composition (Ladle analysis) | 1 (per batch furnace number) | EN10028-4 | EN10028-4 |
2 | Tensile test | 1 (Rolled pc) | EN10028-1 | EN10028-1 |
3 | Impact test at -196C | 3 (Rolled pc) | EN10028-1 | EN10028-1 |
4 | Thickness tension | 3 (Rolled pc) | EN10164 | EN10164 |
5 | Product analysis | 1 (Product pc) | EN10028-1 | EN10028-1 |
6 | Ultrasonic test | Each product pc | EN10160 | EN10160 |
5. Package, marking and certificate
Package, marking and certificate shall conform to EN10028-1.
6. The third party inspection
The chemical composition, tensile test and Charpy -V impact test for plates of X7Ni9 shall be witnessed by surveyor of client.
7. Delivery conditions
The delivery conditions for plates of X7Ni9 shall be Quenching+ Tempered.
8. Other requirements
The other requirements for plates of X7Ni9 shall be accordance with EN10028-4.
MTC accordance with EN10204 3.1
