21 4Cr 1Mo Steel Plate Applications & Ordering Guide

2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo] is specified for industrial fabrications where the drawing or material list names this grade. This applications page explains where the grade is used, what service conditions drive selection, and which certificate details belong on the purchase order. Gangsteel supplies 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo] with EN 10204 mill test certificates.

Typical Applications and Service Conditions

2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo] plate is ordered for pressure equipment, process vessels, heat-exchanger related fabrications, structural members under the governing code, and project packages that call the grade by name. Match the mill test certificate grade mark to the calculation sheet; do not treat near-equivalents as automatic substitutes.

Service drivers include the design temperature and pressure of the governing code (ASME, EN/PED, class society, or project specification), weld procedure qualification needs, toughness or creep allowables where applicable, and inspection scope. Delivery condition Annealed, N+T, or accelerated cool + temper; Grade 22 tempering generally >=675 deg C should be stated explicitly on the purchase order.

Industry Use Cases

Pressure equipment and process: shells, heads, and related platework when drawings name 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo]. Power and energy: boiler and heat-recovery fabrications under the ordered edition. Marine / offshore (when classed): only when the society material list names this exact grade stamp. Always keep heat-number traceability on cut pieces.

Chemical Composition - Supporting Data (2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo])

Heat analysis for Grade 22. Some mill tables still list P/S 0.035 max from older editions - confirm ordered A387/SA387 edition. Class 2 is the higher tensile class. Queue key 21-4Cr-1Mo denotes 2 1/4Cr-1Mo plate practice; tabulated values follow A387 Grade 22 Class 2. Confirm Class 1 vs Class 2 and ordered thickness on the MTC.

Element / rule	Requirement
C (heat)	0.05-0.15
Mn (heat)	0.30-0.60
P, max	0.025
S, max	0.025
Si, max (heat)	0.50
Cr (heat)	2.00-2.50
Mo (heat)	0.90-1.10

Mechanical Properties - Supporting Data (2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo])

Confirm thickness, specimen orientation, and any supplementary impact, UT, or hardness requirements on the PO.

Property	Requirement
Tensile strength	75-100 ksi [515-690 MPa]
Yield strength, min	45 ksi [310 MPa]
Elongation in 50 mm, min	18%
Reduction of area, min (flat)	40%
Delivery / HT	Per A387/SA387; Grade 22 tempering generally >=675 deg C

Related / Near-Equivalent Grades

Near-equivalents are for cross-reference only. They are not automatic code substitutes. Substitution requires engineer approval and matching certificate scope.

System	Grade	Note
ASTM	A387 Grade 22 Class 2	Base ASTM product form
ASME	SA387 Grade 22 Class 2	ASME twin
ASTM / ASME	A387 / SA387 Grade 22 Class 1	Same chemistry, lower tensile class
EN 10028-2	10CrMo9-10	2.25Cr-1Mo European pressure family - confirm edition
ASTM	A387 Grade 11 / 12 Class 2	Lower Cr/Mo bands - not interchangeable

Frequently Asked Questions

Where is 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo] typically applied?

2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo] is applied where design documents, class material lists, or purchaser specs name this grade for pressure, process, structural, or marine fabrications as applicable. Match the MTC marking to the drawing.

What service conditions drive selection of 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo]?

Design temperature and pressure, toughness or creep allowables, weldability, corrosion or process media, and the governing code edition drive selection. Delivery condition Annealed, N+T, or accelerated cool + temper; Grade 22 tempering generally >=675 deg C must align with the ordered specification.

Can a near-equivalent replace 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo] on an applications drawing?

Not without redesign and written approval. Near-equivalents differ in chemistry, heat treatment, impact temperature, or product form. Commercial swaps create non-conformance when the dossier names 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo].

What fabrication notes matter for 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo]?

Use approved WPS/PQR packages for the thickness and filler, control heat input, and preserve heat-number traceability on cut pieces. State any supplementary UT, PMI, or impact tests on the purchase order.

What certificate and marking should an applications PO demand?

EN 10204 3.1 is standard; 3.2 when a purchaser-appointed inspector witnesses tests. The MTC should show heat analysis, tensile results, delivery condition, and heat number aligned with 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo].

How should I RFQ 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo] plate from Gangsteel for a project?

Send 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo], thickness x width x length (or nesting list), quantity, delivery condition, optional NDT/PMI, certificate type, destination, and any dual-mark needs. Note the end use when special flatness or cut-to-size packaging is required.

Ordering and Mill Certificates

State grade 2.25Cr-1Mo (ASTM A387 / ASME SA387 Grade 22) [queue key 21-4Cr-1Mo], dimensions, quantity, delivery condition, optional NDT/PMI, and certificate (EN 10204 3.1 standard; 3.2 when third-party inspection is ordered). Gangsteel supplies export plate and related products with mill test certificates. Contact Gangsteel for stock and mill production RFQs.