ASME SA542 Type B Class 1 Steel Plate | SA542 Type B Cl.1 QT Cr-Mo Vessel Plate
What is ASME SA542 Type B Class 1 Steel ?
ASME SA542 Type B Class 1, also written ASME SA542 TYPE B CL.1, is quenched-and-tempered 2.25Cr-1Mo alloy plate under ASME SA-542/SA-542M. The specification covers Type A, B, C, D and E, and Class 1, 2, 3, 4 and 4a. Type B is the same 2.25Cr-1Mo idea as Type A, with tighter limits on carbon, phosphorus, sulfur, copper, nickel and vanadium. Class 1 is the high tensile Class: 585 MPa yield and 725–860 MPa tensile. As Direct Mill Supply by SHH STEEL, the plate is produced to ASME SA-542/SA-542M.
Buyers write ASME SA542 Type B Class 1, ASME SA542 TYPE B CL.1, SA542 Type B Class 1, SA542 Type B Cl.1, SA542B CL1, SA-542 Type B Class 1 and SA 542 Type B Cl 1. ASTM A542 Type B Class 1 is the companion product spec. A purchase order that only says “SA542 Type B” is incomplete. A purchase order that says “SA542 Grade 22 Class 1” is mixing this book with SA387 Gr.22 Cl.2.
This page is not SA832 22V. SA832 is normalized-and-tempered Cr-Mo-V. SA542 Type B Class 1 is QT 2.25Cr-1Mo without the 22V vanadium band. It is not SA517 Gr.B. It is not SA841 TMCP. It is not ASME SA516 carbon plate. Minimum thickness in the specification is about 5 mm. Maximum thickness is limited by the ability of the heat to meet Class 1 after quench and temper.
For Type A, B and C in Class 1, 2 and 3, the minimum tempering temperature is 565 °C. Dual marking SA542 / A542 Type B Class 1 is available. Certificates can be EN 10204 3.1 or 3.2. Company scope: China steel Mill Agent-SHH STEEL.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Type / Class | ASME SA542 Type B Class 1 | Confirmed |
| Product Specification | ASME SA-542/SA-542M | Applied |
| Companion Spec | ASTM A542 Type B Class 1 | Dual cert available |
| General Requirements | ASME SA-20 / ASTM A20 | Applied |
| Process | Quenched and tempered | Confirmed |
| Alloy idea | 2.25Cr-1Mo, Type B residuals | Confirmed |
| Sister N+T spec | SA-832 / A832 | Not this page |
| Minimum thickness | About 5 mm | Confirm on order |
| Certification | EN 10204 3.1 or 3.2 / third-party | As ordered |
This plate sits in the pressure vessel steel plates family and with ASME SA387 as a related Cr-Mo family, not as a substitute. It does not sit with carbon steel plates or ASTM A36/A36M.
SA-20 still governs marking, testing location, retests and repair rules.
Chemical Composition
ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1 uses Type B chemistry. Class only changes strength. Type A uses the same chromium-molybdenum idea with looser residuals.
Heat Analysis and Product Analysis — ASME SA542 Type B (typical Table 1 limits)
| Element | Heat Analysis (%) | Product Analysis (%) |
|---|---|---|
| Carbon (C) | 0.11 – 0.15 | 0.09 – 0.18 |
| Manganese (Mn) | 0.30 – 0.60 | 0.25 – 0.66 |
| Phosphorus (P), max | 0.015 | 0.015 |
| Sulfur (S), max | 0.015 | 0.015 |
| Silicon (Si), max | 0.50 | 0.50 |
| Chromium (Cr) | 2.00 – 2.50 | 1.88 – 2.62 |
| Molybdenum (Mo) | 0.90 – 1.10 | 0.85 – 1.15 |
| Nickel (Ni), max | Restricted vs Type A | Restricted vs Type A |
| Copper (Cu), max | Restricted vs Type A | Restricted vs Type A |
| Vanadium (V), max | Restricted vs Type A | Restricted vs Type A |
Type B is not Type D. Type D adds a vanadium band of about 0.25–0.35% and is 2.25Cr-1Mo-V. Type C and Type E sit on the 3Cr-1Mo-V band. If the ladle is 2.25Cr-1Mo-V, it is not Type B Class 1.
SHH STEEL reports heat analysis on every certificate, including Cr, Mo and the Type B residual limits, and product analysis when SA-20 requires it.
Mechanical Properties
Class 1 is the high line.
Tensile Requirements — ASME SA542 Type B Class 1
| Property | Requirement |
|---|---|
| Yield strength, min | 585 MPa (85 ksi) |
| Tensile strength | 725 – 860 MPa (105 – 125 ksi) |
| Elongation in 50 mm, min | 14% |
| Density | 7.85 g/cm³ |
| Hardness | Not a default substitute for tensile |
Class 2 is higher still: 690 MPa yield and 795–930 MPa tensile. Class 3 is 515 MPa yield and 655–795 MPa tensile. Class 4 / 4a share 585–760 MPa tensile, with Class 4a at 415 MPa yield. Do not stamp Class 4a as Class 1 because both mention 585 somewhere.
Density is 7.85 g/cm³. Notch toughness is commonly added on reactor plate. Write the temperature, energy, location and orientation. Simulated PWHT is common.
Do not treat 585 MPa yield as permission to substitute SA516 Gr.70, SA533 Type B Class 1 or high strength low alloy plates.
Material Comparison
| Grade | Route | Alloy / strength idea | Swap? |
|---|---|---|---|
| SA542 Type B Cl.1 | QT 2.25Cr-1Mo | Tight residuals, 585 / 725–860 | This page |
| SA542 Type A Class 1 | QT 2.25Cr-1Mo | Looser residuals, same Class | No |
| SA542 Type B Class 4a | QT 2.25Cr-1Mo | 415 / 585–760 | No |
| SA542 Type D Class 4a | QT 2.25Cr-1Mo-V | Vanadium band | No |
| SA387 Gr.22 Cl.2 | Cr-Mo N or N+T family | Not SA542 QT Class 1 | No |
| SA832 22V | N+T Cr-Mo-V | Not QT Type B | No |
| SA517 Gr.B | QT alloy | Different book | No |
SA299 Gr.B, SA225 Gr.D, SA455 and SA285 Gr.C are also vessel plates. None of them is ASME SA542 TYPE B CL.1.
QT Cr-Mo Vessel Service
ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1 is selected when the vessel wants quenched-and-tempered 2.25Cr-1Mo at the Class 1 strength line, with Type B residual control. Typical equipment is high-temperature welded pressure vessels and components written to SA-542 Type B Class 1. Allowable stress comes from ASME Section II Part D after the Code lists this Type and Class.
It is not nickel low-temp plate like SA203 Gr.D. It is not layered QT carbon like SA724. Stainless inquiries belong on ASME SA240/SA240M, ASTM A240/A240M or stainless steel sheets and plates.
Do not form this plate as if it were as-rolled carbon. Quench-and-temper properties are the product. A later PWHT cycle has to be planned and, when required, simulated on coupons.
Weldability
SA542 Type B Cl.1 is killed, fine-grain 2.25Cr-1Mo at Class 1 strength. Welding is Code welding.
Qualify procedures to ASME Section IX. Use consumables written for 2.25Cr-1Mo QT at 725–860 MPa tensile, not a plain carbon procedure and not an unreviewed SA387 Grade 22 procedure. Hydrogen control, preheat, interpass and PWHT follow the qualified procedure and the vessel specification.
Do not copy a SA387 Gr.12 Cl.2 procedure onto Type B Class 1 without review. The fabricator owns the WPS.
Heat Treatment
Plates shall be austenitized, quenched in a suitable liquid medium, then tempered. For Type A, B and C in Class 1, 2 and 3, the minimum tempering temperature is 565 °C (1050 °F). Soak is not less than 1.2 min/mm of thickness and not less than ½ hour. Class 4 and Class 4a use higher temper floors. Do not apply the Class 4a floor of 675 °C to Class 1 and call the plate Class 4a.
If the vessel will see a long PWHT, test coupons shall follow a simulated cycle. This is not the SA832 N+T route. SHH STEEL prints QT, Type B, Class 1, austenitizing and tempering temperatures on the certificate when the mill record carries them.
Delivery Condition
Usual delivery is quenched-and-tempered ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1 plate.
The certificate lists ASME SA542 Type B Class 1 and, when dual certified, ASTM A542 Type B Class 1; heat number; heat analysis including Cr, Mo and Type B residuals; product analysis when ordered; tensile results to the Class 1 table; QT statement; impact and simulated PWHT when ordered. Certificates may be EN 10204 3.1 or EN 10204 3.2.
Dimensions
Usual supply range from SHH STEEL for SA542 Type B Cl.1 QT Cr-Mo vessel plate:
- Thickness: commonly 8 mm – 150 mm, minimum about 5 mm, limited by the ability of the heat to meet Class 1 after QT
- Width: 1500 mm – 4000 mm
- Length: 3000 mm – 12000 mm
- Cut-to-length shells, heads and nest sizes inside those limits
Structural sizes belong on EN 10025-2 or JIS G3106. Weathering plate belongs on EN 10025-5 or Corten A/B. Fine-grain structural belongs on EN 10025-3 or EN 10025-4. QT structural belongs on EN 10025-6.
Tolerances
Dimensional limits follow ASME SA-20. Thickness, width, length, flatness and camber are vessel-plate tolerances. UT to A435 / A577 / A578 is commonly added on reactor plate.
Supplementary Requirements
Most export ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1 orders add extras. SHH STEEL does not assume them.
Charpy details. Temperature, energy, location and orientation.
Simulated PWHT. Same-heat coupons follow the vessel cycle.
NDE. UT to A435 / A577 / A578.
Hydrogen-service extras. When the vessel specification names them.
Third-party. EN 10204 3.2.
Equivalent Material Grades
| Designation | Standard | Notes |
|---|---|---|
| ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1 | ASME SA-542/SA-542M | Code name on this page |
| ASTM A542 Type B Class 1 | ASTM A542/A542M | Companion spec |
| SA542 Type A Class 1 | SA-542 | Same Class, looser residuals |
| SA542 Type B Class 2 / 3 / 4 / 4a | SA-542 | Other Classes |
| SA387 Grade 22 | SA-387 | Related 2.25Cr-1Mo, not this QT Class |
| SA832 22V | SA-832 | N+T Cr-Mo-V |
| EN / JIS / GB 2.25Cr-1Mo QT related | EN / JIS / GB | Project comparison |
| ASME SA387 | SA-387 | Related Cr-Mo family |
DIN 17100, ASTM A516, ASME SA515 and ASTM A285 are not SA542 Type B Class 1.
Applications
| Industry | Typical components |
|---|---|
| High-temperature vessels | ASME SA542 Type B Class 1 shells and ASME SA542 TYPE B CL.1 heads |
| QT 2.25Cr-1Mo equipment | SA542 Type B Cl.1 courses |
| Dual-certified export | SA542 / A542 Type B Class 1 plate |
| Fabrication | SA542 Type B Cl.1 cut to nest sizes |
Ship plate inquiries belong on shipbuilding steel plates or BV Rules. Weathering inquiries belong on weathering steel plates. Stainless inquiries belong on stainless steel products, JIS G4305 or AISI stainless.
Other vessel comparisons: SA203 Gr.B, SA302 Gr.C, A516 Gr.70, SA533 Type C Class 2, SA517 Gr.P.
Why Choose SHH STEEL
SHH STEEL works as a China Mill Direct Exporter for plates to ASME SA-542/SA-542M. On ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1 that means mill pricing, dual SA542/A542 marking, Type B chemistry, recorded quench and temper at the Class 1 floor, tensile results at 585 MPa yield and 725–860 MPa tensile, 3.1 as standard and 3.2 when specified.
We keep Type and Class on the order. Type B is not Type A and is not Type D. Class 1 is not Class 4a. SA542 is not SA387 Grade 22. SA542 is not SA516 Gr.55. SA542 Type B Cl.1 is not SA533 Type C Class 1. If the drawing names N+T Cr-Mo-V, we point the inquiry to SA832. If the shop plans as-rolled delivery, we will say this specification is QT.
Company scope: China steel Mill Agent-SHH STEEL.
FAQ
- What names are used for ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1?Buyers write ASME SA542 Type B Class 1, ASME SA542 TYPE B CL.1, SA542 Type B Class 1, SA542 Type B Cl.1, SA542B CL1, SA-542 Type B Class 1 and SA 542 Type B Cl 1. SHH STEEL prints the wording on the purchase order.
- Is ASME SA542 Type B Class 1 the same as ASTM A542 Type B Class 1?Chemistry and tensile limits match. ASME SA-542 is the Code version. ASTM A542 is the product spec. As China mill-Direct Supply, SHH STEEL dual-certifies both names when the vessel must be stamped.
- What is the yield strength of SA542 Type B Cl.1?585 MPa minimum. Tensile is 725–860 MPa. Elongation is 14% in 50 mm.
- How is ASME SA542 TYPE B CL.1 different from Type A Class 1?Same Class 1 tensile table and the same 2.25Cr-1Mo idea. Type B tightens carbon, phosphorus, sulfur, copper, nickel and vanadium.
- How is ASME SA542 Type B Class 1 different from Class 4a?Class 1 is 585 MPa yield and 725–860 MPa tensile. Class 4a is 415 MPa yield and 585–760 MPa tensile, with a higher temper floor.
- Is SA542 Type B Class 1 the same as SA832 22V or SA387 Grade 22?No. SA832 22V is N+T Cr-Mo-V. SA387 Grade 22 is 2.25Cr-1Mo in the SA387 family. SA542 Type B Class 1 is QT 2.25Cr-1Mo at Class 1 strength.
- Can SHH STEEL issue EN 10204 3.2 for ASME SA542 Type B Class 1?Yes. EN 10204 3.1 is standard. EN 10204 3.2 is arranged when written on the order.
Conclusion
ASME SA542 Type B Class 1 Steel Plate, also searched as ASME SA542 TYPE B CL.1, is quenched-and-tempered 2.25Cr-1Mo plate under ASME SA-542/SA-542M, with Type B residual control and Class 1 strength. Whether the inquiry says ASME SA542 Type B Class 1, ASME SA542 TYPE B CL.1, SA542 Type B Cl.1 or SA542B CL1, SHH STEEL supplies plate with Type B chemistry, recorded QT delivery, 585 MPa yield, and EN 10204 3.1 or 3.2 certification.
As a China mill Distributor, SHH STEEL provides ASME SA542 Type B Class 1 / ASME SA542 TYPE B CL.1 QT Cr-Mo Vessel Plate for ASME Section VIII work that actually names this Type and Class.
Contact SHH STEEL for mill rolling, dual SA542/A542 marking, simulated PWHT testing, 3.2 inspection or a quotation.
ASME SA542 Type B Class 1 Steel Plate, ASME SA542 TYPE B CL.1, SA542 Type B Cl.1, SA542B CL1, SA-542 Type B Class 1, QT Cr-Mo vessel plate, Direct Mill Supply by SHH STEEL
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