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)

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

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

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

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