SA387 GR.12 CL2 Pressure Vessel Steel plate

A387 Grade 12 CL 1,A387 Grade 12 CL 2 are under steel specification standard ASTM A387/A387M for pressure vessel steel plates,alloy steel with Chromium-Molybdenum.The equal steel plate SA387 Grade 12 CL 1 and SA387 Grade 12 CL 2 are under American steel stamdard SA 387/SA 387M.All these alloy steel plates intended primarily for welded boilers and pressure vessels&tanks.Rolling maximum thickness of plates is limited only by the capacity of the composition to meet the specified mechanical property requirements.
 For pressure vessel steel plate SA387 Grade 12 CL 1,the tensile strength shall be within 380 to 550,minimum yield strength is 230 Mpa.For SA387 Grade 12 CL 2 pressure vessel steel plate,the tensile strength is at 450-585 Mpa and yield point shall be above 275 Mpa.Besides the five main elements, Cr-Mo is also in the chemical composition for these alloy steels.

SA387 Gr.12 CL.2 Chemical Composition
Grade	The Element Max (%)
	C	Si	Mn	P	S	Cr	Mo
SA387 Gr.12 Cl.2	0.04-0.17	0.13-0.45	0.35-0.73	0.035	0.035	0.74-1.21	0.40-0.65

 

Grade	SA387 Gr.12 CL.2 Mechanical Property
	Thickness	Yield	Tensile	Elongation
SA387 Gr.12 Cl.2	mm	Min Mpa	Mpa	Min  %
	t≦50	275	450-585	22
	50<t≦200	275	450-585	19

Refered Standards for ASME SA387 Alloy Steel Plate

ASME

• SA20/A20M: General requirements for pressure vessel plates.
• SA370: Test specification for mechanical properties of steel
• SA435/A435M: For straight-beam ultrasonic examination of steel plates
• SA577/A577M: For ultrasonic angle beam examination of steel plates
• SA578/A578M: For straight beam UT examination of rolled steel plates in special applications
• SA1017/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.

Heat Treatment for SA387 Chrom Moly Alloy Steel Plate 

Chrome moly alloy steel plate under ASME SA387 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:

Grade	Temperature, °F [°C]
2, 12 and 11	1150 [620]
22, 22L, 21, 21L and 9	1250 [675]
5	1300 [705]