ASME SA387 Grade 11 Class2

ASME SA387 Grade 11 Class 2 is Chrom-Moly steel plate used for welding boilers and pressure vessles designed for high temperature serivce, nominal chrome content at 1.00% to 1.50%, and Moly 0.45% to 0.65% for SA387 GRADE 11 material.


The higher content of chromium will provide excellent corrosion and oxidation resistance, so the material could be used for sour services, and to storage oil, gas, liquid for different industries. 

Refered Standards for ASTM A387 Alloy Steel Plate


A20/A20M: General requirements for pressure vessel plates.
A370: Test specification for mechanical properties of steel
A435/A435M: For straight-beam ultrasonic examination of steel plates
A577/A577M: For ultrasonic angle beam examination of steel plates
A578/A578M: For straight beam UT examination of rolled steel plates in special applications
A1017/A1017M: Specification for pressure vessle plates of alloy steel, chromium-molybdenum-tungsten

AWS Specification

A5.5/A5.5M: Low alloy steel electrodes for shield metal arc welding.
A5.23/A5.23M: Low alloy steel electrodes for fulxes for submerged arc welding.
A5.28/A5.28M: For gas shielded arc welding
A5.29/A5.29M: For flux cored arc welding.

SA387 Grade 11, 22 Chemical Composition


Nominal Chromium Content, %

Nominal Molybdenum Content, %




22, 22L












Except 21L, 22L and 91, each grade is available in two classes of tensile strength levels as defined in the tensile requirements tables. Grades 21L and 22L only has Class 1, and Grade 91 only has Class2.

Heat Treatment for ASME SA387 Grade 11 Class 2

Chrome moly alloy steel plate under ASTM A387 shall be killed steel, with thermally treated either by annealing, normarlizing and tempering. Or in case agreed by buyer, accelerated cooling from the austenitizing temperature by air blasting or liquid quenching, followed by tempering, minimum tempering temperatures shall be as below table:


Temperature, °F [°C]

2, 12 and 11

1150 [620]

22, 22L, 21, 21L and 9

1250 [675]


1300 [705]

Our Supply Range:

Description: Chrome Moly Alloy Steel Plate ASME SA387
Grade: SA387 GRADE 11, 22, 12, 5, 9, 91
Manufacturing Types: Hot Rolled, Heat Treated
Thickness: 5 to 150 mm
Width: 0.6m to 3m
Length: 6m, 12m, customized
Surface: Natural, Painted
Packing: Standard sea packing, bundled with streel strip.
Customized cutting: Laser Cut, Plasma Cut, CNC Cut.

Related Products

ASTM A387 Grade 11, 22, 91 Plate
ASTM A537 Class 1, 2 Plates
ASTM A572 Grade 50, 60 Steel Plates
Laser Cut Metal Steel / CNC Laser Cutting
Plasma Cut / CNC Plasma Cutting Steel