ASTM A387 Plates
Most commonly used steel specifications for Chrome Moly plate are ASME SA387 and ASTM A387
Chemical and mechanical properties of the ASME and ASTM specifications are the same.
Gnee steel supplies Chrome Moly plates to ASME SA387 and ASTM A387 both from stock and, where required by the customer, cut to size and shape. SA387 and A387 are described as a “Standard Specification for Pressure Vessel Plates, Alloy Steel, and Chromium-Molybdenum.
Chrome Moly Plate
ASME SA / ASTM A387 Gr 11 Cl. 2, ASME SA / ASTM A387 Gr 22 Cl. 2, ASME SA / ASTM A387 Gr 5 Cl. 2, ASME SA / ASTM A387 Gr 9 Cl. 2.
Each grade except Grades 21L, 22L, and 91 is available in two classes of tensile strength described as Class 1 and Class 2.
The most regularly specified grades and hence those that are most readily available from stock are Grades 12, 11, 22, 5, 91 and 9 and in most case stock plates will be produced to the tensile requirements of Class 2.
As with all ASME and ASTM pressure vessel steels, Chrome Moly to SA387 and A387 is produced in conformity to SA20 / A20 which outlines the testing and retesting methods and procedures, permissible variations in dimensions and weight, quality and repair of defects, marking, loading, and ordering information.
|GRADE||NOMINAL CR CONTENT (%)||NOMINAL MO CONTENT (%)|
|GR. 2||GR. 12||GR. 11||GR. 22||GR. 22L||GR. 21||GR. 21L||GR. 5||GR. 9||GR. 91*|
Tensile Requirements For Class 1 Plates
|GRADE||TENSILE (MPA)||YIELD (MPA)||ELONG. (50MM)||REDUC’N OF AREA*|
|2, 12||380 – 550||230 min||22% min||–|
|11||415 – 585||240 min||22% min||–|
|22, 21, 5, 9||415 – 585||205 min||18% min||40% min|
|21L, 22L||415 – 585||205 min||18% min||40% min|
Tensile Requirements For Class 2 Plates
|GRADE||TENSILE (MPA)||YIELD (MPA)||ELONG. (50 MM)||REDUC’N OF AREA*|
|2||485 – 620||310 min||22% min||–|
|11||515 – 690||310 min||22% min||–|
|12||450 – 585||275 min||22% min||–|
|22, 21, 5, 9||515 – 690||310 min||18% min||40% min|
|91||585 – 760||415 min||18% min||–|