ASME SA225 Grade D Steel Plate | SA225 Gr.D Mn-V-Ni Vessel Plate

ASME SA225 Grade D is the mid-strength grade in the current ASME SA-225/SA-225M. The specification covers manganese-vanadium-nickel alloy steel plates intended primarily for welded layered pressure vessels. The live standard has two grades only: Grade C and Grade D. Older talk about Grade A or Grade B belongs to withdrawn editions. As Direct Mill Supply by SHH STEEL, the plate is produced to ASME SA-225/SA-225M.

The same plate is written SA225 Gr.D, SA225GRD, SA225 GR D, SA-225 Grade D, SA225 Grade D, ASME SA225 GR.D, ASME SA225GRD, ASTM A225 Grade D, A225 Gr.D, A225GRD and A/SA225 Grade D. They all mean Grade D. ASTM A225/A225M is the product companion.

Grade D is not the high-strength line. Grade C takes 725–930 MPa tensile at all thicknesses. Grade D takes 550–725 MPa through 75 mm and 515–690 MPa over 75 mm. If the drawing says Grade C, do not ship Grade D and call it “close.” If the drawing says Grade D, do not ship Grade C as a silent upgrade. Carbon caps are also different: Grade C 0.25% max, Grade D 0.20% max.

This is not carbon vessel plate. If the drawing says SA285 Gr.C or SA516 Gr.70, open that page. SA285 is low-to-intermediate tensile carbon. SA516 is fine-grain carbon. ASME SA225 Grade D is a Mn-V-Ni alloy. It is also not a nickel cryogenic grade like SA203 Gr.D or SA203 Gr.E. Those plates live on 3.5% nickel. SA225 Grade D lives on manganese, vanadium and 0.40–0.70% nickel.

It is not QT 690 MPa plate like SA517 Gr.Q. SA517 is quench and temper. SA225 Grade D is normalized at all thicknesses. That sentence is in the heat-treatment clause, not in a mill brochure.

The steel shall be killed and shall conform to the fine austenitic grain size requirement of ASME SA-20 / ASTM A20. Maximum thickness is limited only by the ability of the chemistry to meet the tensile table. Mills commonly offer about 8–150 mm; heavier sizes are an enquiry.

For Code work the plate is used under ASME Section VIII. Dual marking ASME SA225 Grade D / ASTM A225 Grade D is available. Certificates can be EN 10204 3.1 or EN 10204 3.2.

When a project is still choosing alloy vessel plate, a China mill Agent path through SHH STEEL puts SA225GRD next to SA302 Gr.B, SA302 Gr.C, SA387 Gr.22 Cl.2 and SA537 Cl.1. Mn-Mo, Cr-Mo, carbon QT and Mn-V-Ni are four different purchases.

This plate is a vessel product. It is not structural ASTM A36 steel plate. It is not silicon-killed high-temp carbon like SA515 Gr.70.

Chemistry for ASME SA225 Grade D is reported as heat analysis and product analysis under ASME SA-225/SA-225M Table 1. Carbon is lower than Grade C. Manganese is allowed higher.

Heat Analysis — ASME SA225 Grade D / SA225 Gr.D

Product Analysis — SA225GRD / A225 Grade D

Carbon 0.20% max applies to both heat and product analysis. That is tighter than Grade C (0.25% max). Manganese is a maximum, not a min–max band: 1.70% heat, 1.84% product. Vanadium is 0.10–0.18% heat. Nickel is the same window as Grade C, 0.40–0.70% heat.

Compare that ladle with nearby alloys before anyone tries a silent swap. SA203 Gr.A and SA203 Gr.B live on nickel, not vanadium. SA302 Gr.A and SA302 Gr.D live on molybdenum. SA387 Gr.11 Cl.2 lives on chromium-molybdenum. Grade D in SA-225 is none of those ladles.

A Grade C heat cannot be recertified as Grade D if carbon sits above 0.20% or if vanadium sits in the Grade C-only slice without meeting Grade D tensile. If the drawing says ASME SA225 Grade D or ASME SA225GRD, the ladle must sit in the Grade D table. SHH STEEL reports heat analysis on every certificate and adds product analysis when ASME SA-20 or the vessel specification requires it.

Tighter phosphorus, sulfur or residuals are supplementary. Vacuum treatment and other A20 chemistry items are available when written on the order.

Grade D uses two tensile lines by thickness. That is the first thing a designer should read.

Tensile Requirements — ASME SA225 Grade D per ASME SA-225/SA-225M

Yield is determined by the 0.2% offset method or the 0.5% extension-under-load method. A 70 mm plate is tested to the 415 MPa line. An 80 mm plate is tested to the 380 MPa line. Do not apply the thin-line yield to a 90 mm plate and call the heat compliant.

Grade C in the same specification is 725–930 MPa tensile and 485 MPa yield at all thicknesses. That is why Grade C is the high-pressure choice and Grade D is the mid-strength layered-vessel choice.

Density is 7.85 g/cm³. Hardness is not a default line in SA-225. A special HBW window is supplementary.

Charpy impact is not a hidden default at −20 °C or −46 °C. If the vessel needs a stated test temperature and energy, that is a supplementary requirement under ASME SA-20. Write the temperature on the purchase order. “Moderate and lower temperature” in commercial language does not replace a number on the MTC.

Specimens follow ASME SA-20. If simulated PWHT is specified, coupons from the same SA225 Gr.D heat follow the vessel cycle before tensile and impact testing.

Compare strength class carefully. SA537 Cl.2 is carbon QT. SA517 Gr.F is QT 690 MPa class with a 65 mm ceiling. A516 Gr.70 is fine-grain carbon at 485–620 MPa. SA225 Grade D is not a substitute for those pages.

Order ASME SA225 Grade D when the drawing names Grade D. SHH STEEL does not swap SA225GRD for A515 Gr.70 or SA517 Gr.P without a written revision.

ASME SA225 Grade D exists because layered vessels need a weldable Mn-V-Ni plate that is stronger than ordinary carbon and more formable than Grade C. Vanadium refines grain. Nickel at 0.40–0.70% helps toughness. Manganese carries hardenability for the normalized condition. Lower carbon than Grade C is the weldability argument.

Allowable stress for Code work comes from ASME Section II Part D for SA-225 Grade D, not from a mill flyer. Impact temperature is an order number.

Typical use is layered shells, intermediate-pressure drums specified to SA-225, and other fusion-welded equipment written as Mn-V-Ni vessel plate. It is not a replacement for SA387 Gr.91 Cl.2 creep service and not a replacement for SA203 Gr.A nickel low-temp service.

SA225GRD is a vanadium-bearing alloy vessel plate. Welding is not the same job as welding SA516 Gr.60 or SA285 Gr.B.

Procedures for Code work are qualified to ASME Section IX. Consumables should match the required joint strength and toughness. Low-hydrogen practice is mandatory thinking. Grade D carbon is 0.20% max, which is kinder than Grade C, but vanadium and manganese still raise hardenability enough that a cold, restrained start can crack.

Preheat depends on thickness, restraint, hydrogen and the qualified WPS. After welding, many shops want to PWHT. Simulated PWHT of mill coupons should be on the purchase order whenever the vessel specification includes PWHT.

Do not copy a SA387 Gr.22 Cl.1 Cr-Mo procedure or a SA517 Gr.A QT procedure onto ASME SA225 Grade D without review. The fabricator owns the qualified WPS.

Heat treatment of ASME SA225 Grade D is explicit in the specification:

Grade D plates of all thicknesses shall be normalized.

That is not optional language. As-rolled Grade D is not SA225 Grade D. Grade C plates 50 mm and under are usually supplied as-rolled and may be ordered normalized; Grade D does not get that option.

Holding time follows mill practice and ASME SA-20 thickness rules. If the purchaser fixes a normalizing temperature band or a subsequent stress relief because later PWHT is planned, those limits go on the mill instruction and onto the certificate.

Do not apply the quench-and-temper route used for SA517 Gr.E or SA517 Gr.H and call the plate SA225 Gr.D.

SHH STEEL reports the actual heat-treatment condition on the MTC for every SA225 Gr.D plate.

Usual delivery is normalized alloy vessel plate. Additional stress relieving is supplied when specified.

The certificate lists ASME SA225 Grade D and, when dual certified, ASTM A225 Grade D; heat number; heat analysis; product analysis when ordered; tensile results by thickness line; heat-treatment temperatures; Charpy results when ordered; and supplementary tests.

Surface is vessel-plate quality. Shot blasting and shop primer are available.

Certificates may be EN 10204 3.1 or EN 10204 3.2.

Usual supply range from SHH STEEL for SA225 Gr.D Mn-V-Ni vessel plate:

• Thickness: 8 mm – 150 mm (heavier sizes by mill enquiry; thickness is limited by chemistry meeting the tensile table)
• Width: up to about 4000 mm
• Length: up to about 12000 mm

State thickness clearly. At 75 mm the tensile table changes. A 80 mm plate is ordered and tested to the lower yield line.

Dimensional limits follow ASME SA-20. Thickness, width, length, flatness and camber are vessel-plate tolerances.

Ultrasonic testing to A435, A577 or A578 is commonly added on layered-vessel plate. Extra-flatness is a negotiated item.

Most export ASME SA225 Grade D orders add tests beyond the base tensile table. SHH STEEL does not assume these extras.

Simulated PWHT. Same-heat coupons follow the vessel cycle. Tensile and Charpy are run after that cycle.

Charpy details. Temperature, energy, specimen orientation and location as agreed. Not a hidden default.

NDE. UT to A435 / A577 / A578; edge MT/PT after cutting. Layered-vessel work often writes UT on the mill order.

Hardness survey. Surface or through-thickness HBW/HV after normalize or after simulated PWHT.

Restricted chemistry. Tighter P, S, residuals or vacuum treatment per SA-20.

HIC / NACE. Only when TM0284 or MR0175 / ISO 15156 is cited. Grade D is not automatically sour-service plate.

Z-direction. A770 or Z15/Z25/Z35 for nozzles and strained joints.

Third-party. Witness of normalizing, testing and documents. Output can be EN 10204 3.2.

If an item is not on the purchase order, it is not assumed.

These names are used for project comparison. They are not automatic substitutes.

ASME SA225 Grade D / SA225 Gr.D is selected when a Section VIII or layered vessel needs Mn-V-Ni alloy strength below the Grade C tensile window.

Do not use this grade as a silent stand-in for SA387 Gr.5 Cl.2 or SA517 Gr.S. Those drawings name different alloys and different heat treatments.

SHH STEEL works as a China Mill Direct Exporter for plates to ASME SA-225/SA-225M. On ASME SA225 Grade D that means mill pricing, dual SA225/A225 marking, heat and product analysis including the 0.10–0.18% vanadium band and 0.20% carbon cap, normalizing on every thickness, thickness-correct tensile lines at 75 mm, 3.1 as standard and 3.2 when specified.

We also keep the order on the right grade. Grade D is not Grade C. SA225 is not SA285 Gr.A. SA225 is not SA516 Gr.55. SA225 Gr.D is not SA517 Gr.Q. If the drawing is nickel low-temp, we point the inquiry to SA203. If the drawing is Cr-Mo elevated-temp, we point it to SA387. If the drawing is QT 690, we point it to SA517. If the drawing is Grade C, we will not ship Grade D.

Company scope: China steel Mill Agent-SHH STEEL.

ASME SA225 Grade D Steel Plate is the mid-strength manganese-vanadium-nickel vessel grade in the current ASME SA-225/SA-225M, which lists only Grade C and Grade D. Whether the inquiry says SA225 Gr.D, SA225GRD, ASME SA225 GR.D, ASME SA225GRD or A225 Grade D, SHH STEEL supplies plate with heat and product analysis, mandatory normalizing, thickness-correct tensile lines at 75 mm, agreed Charpy and simulated PWHT, and EN 10204 3.1 or 3.2 certification.

As a China mill Distributor, SHH STEEL provides ASME SA225 Grade D / SA225 Gr.D Mn-V-Ni Vessel Plate for ASME Section VIII layered-vessel fabrication.

Contact SHH STEEL for mill rolling, dual SA225/A225 marking, 3.2 inspection or a quotation.

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