This specification covers manganese-vanadium-nickel alloy steel plates intended primarily for welded layered pressure vessels. Plates that shall be used are of Grades C and D and their maximum thickness is limited only by the capacity of the chemical composition to meet the specified mechanical property requirements. The steel shall be killed and shall conform to fine austenitic grain size requirements. The plates shall undergo heat treatment. The mechanical properties such as tensile strength, yield strength, and elongation shall be determined by subjecting the plates to a tension test.

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

1.2 Plates under this specification are available in two grades having different strength levels as follows:

Grade

Tensile Strength, ksi [MPa]

C

 105–135 [725–930]

D

    3 in. [75 mm] and under

80–105 [550–725]

    Over 3 in. [75 mm]

75–100 [515–690]

1.3 The maximum thickness of plates is limited only by the capacity of the chemical 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 the 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.