ASTM A387/A387M Grade 12 Class 2 Introduce

ASTM A387/A387M Grade 12 Class 2 is a low alloy steel plate for use in pressure vessels and boilers for welded construction. It is also suitable for use in heat exchangers, research reactors and organic and inorganic chemical reactors.

Smelting temperature:1154°C - 1493°C

Application:Pressure vessel plate, alloy steel, chrome molybdenum

ASTM A387/A387M Grade 12 Class 2 Material Chemical Composition

The chemical composition of the ASTM A387/A387M Grade 12 Class 2 steel are as follows:

ElementMinMax
Molybdenum (Mo)0.45000.6000
Chromium (Cr)0.80001.1500
PhOsphorus (P)-0.0350
Sulfur (S)-0.0350
Manganese (Mn)0.40000.6500
Silicon (Si)0.15000.4000
Carbon (C)0.05000.1700
Sulfur (S)-0.0400
Silicon (Si)0.13000.4500
Sulfur (S)-0.0250
PhOsphorus (P)-0.0250
Molybdenum (Mo)0.40000.6500
Manganese (Mn)0.35000.7300
Chromium (Cr)0.74001.2100
Carbon (C)0.04000.1700

ASTM A387/A387M Grade 12 Class 2 Material Mechanical Properties

ASTM A387/A387M Grade 12 Class 2 steel requires either normalizing, tempered/quenched, or annealing treatments. Normalizing temperatures should be set between 845-925°C followed by air cooling. Tempered/quenched treatments involve heating the steel to 790-845°C and then quenching the steel in water or oil. Alternately, annealing treatments can be done at a temperature range of 760-845°C and air cooling.

The mechanical properties of the ASTM A387/A387M Grade 12 Class 2 steel are as follows:

YieldRp0.2 ≤ 282 (MPa)
TeileRm≤ 549 (MPa)
ImpactKV/Ku24(J)
ElongationA11%
Reduction in cross section on fractureZ41%
As-Heat-Treated ConditionSolution and Aging, Annealing, Ausaging, Q+T,etc
Brinell hardness (HBW)331

ASTM A387/A387M Grade 12 Class 2 Material Thermal Properties

The thermal performance parameters of the ASTM A387/A387M Grade 12 Class 2 steel are as follows:

Temperature (°C)12748498
Modulus of elasticity (GPa)-323-
Mean coefficient of thermal expaion ×10-6/(°C)--44
Thermal conductivity (W/m·°C)-23.334.2
Specific thermal capacity (J/kg·°C)-342-
Specific electrical resistivity (Ω mm²/m)0.34--
Deity (kg/dm³)--223
Poisson’s coefficient, ν--441

ASTM A387/A387M Grade 12 Class 2 Material Machining Technology

ASTM A387/A387M Grade 12 Class 2 steel is a popular choice among manufacturers and machinists as it is corrosion and oxidation-resistant, tough, and affordable. It is also heat-treatable and can be machined with relative ease.