What Is SA387 Gr.22 Class 2
ASME SA387 Gr.22 Cl.2 is a chromium-molybdenum alloy steel plate manufactured per ASTM A387 or ASME SA387, specifically engineered for welded boilers and pressure vessels designed for elevated-temperature service. With a nominal composition of 2.25 percent chromium and 1.0 percent molybdenum, this grade exhibits excellent high-temperature strength, creep resistance, and resistance to high-temperature hydrogen attack, making it the premier material worldwide for hydroprocessing reactors, high-pressure heat exchangers, and power plant boilers.
Standards and Equivalents
The governing standards are ASTM A387 and ASME SA387, with SA-20 general requirements as supplementary. Equivalents include EN 10028-2 10CrMo9-10 with material number 1.7380, DIN 17155 10CrMo910, GB/T 713 12Cr2Mo1R, and JIS G4109 SCMV4.
Composition and Mechanical Properties
Class 2 composition is carbon 0.05 to 0.15 percent, manganese 0.30 to 0.60 percent, phosphorus 0.035 percent, sulfur 0.035 percent, silicon 0.50 percent maximum, chromium 2.00 to 2.50 percent, and molybdenum 0.90 to 1.10 percent. The plate is delivered normalized and tempered with a minimum yield strength of 310 MPa, tensile strength of 515 to 690 MPa, elongation of 18 percent in 50 mm, and reduction of area of 45 percent.
Key Properties
Outstanding elevated-temperature strength: the N+T condition provides reliable service in the 540 to 565 degrees C range per design code. Excellent HTHA resistance: the 2.25Cr-1Mo composition is the industry standard for hydrocrackers, hydrotreaters, and steam-methane reformers in compliance with API RP 941 guidance. Superior oxidation resistance: the 2.25 percent chromium forms a protective oxide layer, ensuring long-term integrity in steam systems and boiler drums. Excellent weldability: with proper preheating and PWHT, the grade welds across SAW, GTAW, and SMAW processes. Lower lifecycle costs: the combination of creep-rupture strength, oxidation resistance, and weldability extends equipment life and minimizes maintenance.
Main Uses
Oil and gas and petrochemical: hydrocrackers, hydrotreaters, desulfurization vessels, coke drums, and separators. Power generation: boiler drums, steam headers, high-temperature piping, and turbine casings. Chemical processing: reactors, high-pressure heat exchangers, and methanation furnaces. Refining: hydrogen service vessels, catalytic reformer vessels, and hot separators.
Frequently Asked Questions
Q: Is SA387 Gr.22 Cl2 stronger than Class 1?
A: Yes, Class 2 achieves higher strength through heat treatment while sharing the same composition.
Q: Which is better for refinery reactors, Class 1 or Class 2?
A: Class 2, overwhelmingly, for hydrocrackers and high-temperature high-pressure vessels.
Q: Can Class 1 be upgraded to Class 2?
A: Yes, through quenching and tempering or accelerated cooling followed by tempering.
Q: What is the EN equivalent?
A: EN 10028-2 10CrMo9-10, material number 1.7380.
Q: What thickness range is available?
A: 8 to 250 mm with widths of 1000 to 4000 mm and lengths to 18000 mm.
Q: What is the maximum plate weight?
A: Up to about 25 tons per plate depending on dimensions.
For ASME SA387 Gr.22 Cl2 plate quotations with equivalents and certification, contact our sales team.
