This specification covers nickel-alloy steel plates intended primarily for welded pressure vessels. As a steel making practice, the steel shall be killed and shall conform to fine grain size requirements. The heat treatment requirements for all plates are presented, and all plates under Grades A, B, D, and E shall be normalized as required. The steel shall conform to the required chemical compositions. Two mechanical test requirements are presented that includes, tension test requirements and impact test requirements.

1.1 This specification2 covers nickel-alloy steel plates intended primarily for welded pressure vessels.

1.2 Plates under this specification are available with four strength levels and two nickel compositions as follows:

Grade

Nominal Nickel
Content %

Yield Strength, min, ksi [MPa]

Tensile Strength, min, ksi [MPa]

A

2.25

37 [255]

65 [450]

B

2.25

40 [275]

70 [485]

D

3.50

37 [255]

65 [450]

E

3.50

40 [275]

70 [485]

F

3.50

    2 in. [50 mm] and under

55 [380]

80 [550]

    Over 2 in. [50 mm]

50 [345]

75 [515]

1.3 The maximum thickness of plates is limited only by the capacity of the composition to meet the specified mechanical property requirements.

1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents. Therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.