ASTM A387 Grade 91 Class 2 Steel Plate | A387 Gr.91 Cl.2 9Cr-1Mo-V Vessel Plate

ASTM A387 Grade 91 Class 2, also searched as A387 Gr.91 Cl.2, A387GR91CL2, A387GR91 CL2, A387GR.91 Class 2, A387-91 Cl.2, SA387 Grade 91 Class 2 and P91 plate, is Grade 91 in ASTM A387/A387M. The book is chromium-molybdenum plate for welded boilers and elevated-temperature vessels. Nominal alloy is 9Cr-1Mo-V-Nb. Grade 91 is Class 2 only. There is no Class 1 for this grade. This page is not ASME SA387 Grade 9 Class 2. Grade 9 is 9Cr-1Mo without V and Nb. This page is not ASME SA387 Grade 5 Class 2. Grade 5 is 5Cr-0.5Mo. This page is not EN 10028-2 X10CrMoVNb9-1 unless both books are met.

Tensile is 85–110 ksi / 585–760 MPa. Yield is 60 ksi / 415 MPa min. Delivery is normalized and tempered, or accelerated cooling plus temper. Annealed plate cannot be Grade 91. Minimum temper for Grade 91 is 1350 °F / 730 °C. SHH STEEL is a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin). We buy this grade from qualified Chinese mills, check the certificate against A387 / SA-387 and A20 / SA-20, and ship it to fabricators in the USA, Europe, Middle East, Southeast Asia, Africa and South America.

For ASME Code work the name on the certificate should be SA-387 Grade 91 Class 2. Related category pages: ASTM A387 and ASME SA387.

This plate sits in pressure vessel steel plates and ASTM A387. European P91 sisters belong on EN 10028-2.

Heat analysis and product analysis follow ASTM A387 Table 1 for Grade 91. Grade 91 chemistry is tighter than Grade 9.

Heat Analysis and Product Analysis — ASTM A387 Grade 91

Grade 91 is not Grade 9. Grade 9 has no V/Nb/N window and a different tensile table. SHH STEEL prints heat analysis on every certificate and product analysis when ordered. Density is 7.85 g/cm³.

Buyers search A387 Gr.91 Cl.2 mechanical properties, A387GR91CL2 yield, P91 tensile and A387 Grade 91 Class 2 tensile.

Tensile and Yield — ASTM A387 Grade 91 Class 2

Grade 9 Class 2 is 515–690 MPa with 310 MPa yield. Do not quote Grade 9 numbers on a Grade 91 order. Grade 91 is Class 2 only.

There is no official one-to-one worldwide swap for A387 Gr.91 Cl.2. What buyers compare is the P91 / 9Cr-1Mo-V-Nb idea in other books, not an automatic substitute.

In the United States the Code name is ASME SA-387 Grade 91 Class 2. That is the same chemistry and the same Class 2 tensile table. Grade 91 has no Class 1. ASME SA387 Grade 9 Class 2 is 9Cr-1Mo without V and Nb.

In Europe the nearest comparison is EN 10028-2 X10CrMoVNb9-1, commonly called P91. See X10CrMoVNb9-1. That page sits on EN 10028-2.

In China buyers often search 10Cr9Mo1VNb as a P91-type comparison. That is not an automatic A387 Grade 91 substitute unless both books are met.

Dual marking is possible only when both books are fully met.

Buyers pick A387 Gr.91 Cl.2 when a file wants P91 / 9Cr-1Mo-V-Nb at the Grade 91 tensile table. Search phrases such as A387GR91CL2, A387 Grade 91 Class 2, SA387 Grade 91 Class 2 and P91 plate all point here.

It is not a substitute for ASME SA387 Grade 9 Class 2. That grade has no V/Nb/N window. It is not a substitute for ASME SA387 Grade 22 Class 2. That grade is 2.25Cr-1Mo. Dual marking with SA-387 Grade 91 Class 2 is the normal Code route.

SHH STEEL supplies this plate to fabricators in the United States, Mexico, South America, Europe, the Middle East, Africa and Asia.

A387 Grade 91 Class 2 is killed 9Cr-1Mo-V-Nb vessel plate at 585–760 MPa. Treat welding as production welding, and as ASME Section VIII / PED welding when the equipment is a vessel.

Qualify to the applicable code. Consumables must match a P91 / 9Cr-1Mo-V family. A procedure written for ASME SA516 Grade 70 is the wrong alloy. A procedure written for ASME SA387 Grade 9 Class 2 is not a P91 procedure. A procedure written for EN 10028-2 X10CrMoVNb9-1 is the usual European comparison. Preheat, interpass and PWHT must stay inside the qualified WPS. Minimum temper on the plate is 730 °C. The fabricator owns the WPS. SHH STEEL can share mill heat data for that review.

Usual delivery from SHH STEEL for A387 Gr.91 Cl.2 is normalized and tempered, or accelerated cooling plus temper. Minimum tempering temperature for Grade 91 is 1350 °F / 730 °C.

Annealed plate cannot be Grade 91. If the mill only annealed the heat, it cannot be certified A387 Grade 91 Class 2.

If the vessel will see PWHT, say so. Simulated PWHT on test coupons is worth naming on P91 work. Extra simulation, 3.2 hold points or special NDE add time. Plan about two months when those extras are on the order.

The certificate lists ASTM A387 Grade 91 Class 2 and, when ordered, ASME SA-387 Grade 91 Class 2; heat number; heat analysis; product analysis when ordered; tensile to the Grade 91 Class 2 table; heat-treatment route. Certificates may be EN 10204 3.1 or EN 10204 3.2.

Usual supply range from SHH STEEL for A387 Gr.91 Cl.2 9Cr-1Mo-V vessel plate:

• Thickness: commonly 6 mm – 150 mm, thicker by mill agreement
• Width: 1500 mm – 4000 mm
• Length: 3000 mm – 12000 mm

Maximum thickness is limited by the ability of the composition to meet Grade 91 Class 2 tensile. 9Cr-1Mo without V/Nb belongs on ASME SA387 Grade 9 Class 2. 2.25Cr-1Mo plate belongs on ASME SA387 Grade 22 Class 2.

Dimensional limits for ASTM A387 Grade 91 Class 2 follow ASTM A20 / ASME SA-20 unless the purchase order names another table. Do not apply ASTM A36 structural tolerances to a Cr-Mo-V vessel plate without writing them.

Typical thickness tolerance idea for A387 Gr.91 Cl.2 (A20 / SA-20 reference)

Width on 1500–4000 mm plate is commonly held to about ±20–25 mm unless the mill quote names a tighter extra. Length on 3000–12000 mm plate is commonly held to about +50 / 0 mm or ±25 mm by mill practice. Flatness follows A20 / SA-20 unless a tighter class is written. Edge condition is mill edge or cut edge as ordered. If the vessel calculation used minimum thickness after corrosion, write the allowed minus on the RFQ. SHH STEEL will not assume a zero-minus extra on A387GR91CL2 unless the order says so.

ASTM A387 Grade 91 Class 2 already defines chemistry, Class 2 tensile and the 730 °C minimum temper. Extra items still have to be written on the purchase order. SHH STEEL will not assume them from the grade name alone.

Code name. Write SA-387 Grade 91 Class 2 when the equipment is ASME Code work.

Heat-treatment route. Write normalized and tempered, or accelerated cooling plus temper. Do not accept annealed plate as Grade 91.

Charpy details. Grade 91 does not assume a default impact temperature. Write temperature, joules, location and orientation if impact is required.

Simulated PWHT. When the vessel will be stress-relieved, name hold temperature, hold time and cooling rate on the coupon.

Product analysis. Especially C, Cr, Mo, V, Nb, N, P and S.

Through-thickness / Z-test. Name Z15, Z25 or Z35 when the plate will be welded in the thickness direction.

NDE. A20 / SA-20 ultrasonic extras, ASTM A435 or ASTM A578 as named. Write scanning extent and acceptance class.

Hardness. If the destination file caps hardness after heat treatment or after simulated PWHT, write the max HB and the test location.

HIC / SSC / NACE. Only when the equipment is sour service. A387 Gr.91 Cl.2 is not automatically NACE MR0175 / ISO 15156.

Third-party witness. EN 10204 3.2 with SGS, TÜV, BV, ABS, CCS, DNV or the inspector named. Hold points for heat treatment, chemistry, tensile and UT should be listed on the ITP.

Identification and stamping. Heat number, grade A387 Grade 91 Class 2 / A387 Gr.91 Cl.2, SA-387 Grade 91 Class 2 when ordered, thickness and mill logo on each plate.

A387 Grade 91 Class 2 is the plate for a file that wants P91 / 9Cr-1Mo-V-Nb. It is the wrong plate for Grade 9. That work is ASME SA387 Grade 9 Class 2. It is the wrong plate for 2.25Cr-1Mo. That work is ASME SA387 Grade 22 Class 2.

SHH STEEL sources ASTM A387 Grade 91 Class 2 from first-line Chinese mills and ships it on worldwide terms. Partner mills include Wuyang (Wugang), Angang, Shougang, Hanye, Anyang Iron & Steel, Baosteel, Xinyu, Xingcheng, Yongjin, Tsingshan, TISCO (Taiyuan), Jiuquan (JISCO), Lianzhong, Zhangpu and Baoxin, plus other qualified mills when the size or heat-treatment route requires it.

Mill test certificates are issued to EN 10204 3.1 as standard. EN 10204 3.2 is arranged when the order names a third-party hold point.

Usual stock and rolling thickness: 8 mm, 10 mm, 12 mm, 16 mm, 20 mm, 25 mm, 30 mm, 32 mm, 36 mm, 40 mm, 50 mm, 60 mm, 80 mm, 100 mm, thicker by mill agreement.

Processing: CNC or flame cutting, bevel, flattening, UT to the named class.

Trade terms: FOB Shanghai main, CIF destination available. Payment: TT, LC, or TT + LC.

Ocean time from Shanghai: US West 14–18 days; US Gulf 28–35 days; Rotterdam / Antwerp 28–35 days; Jebel Ali 18–25 days; Singapore 7–12 days; other ports quoted.

Third-party: SGS, TÜV, BV, ABS, CCS, GL, VL, DNV, RINA, NK, KR, or the inspector named.

SHH STEEL is a global steel mill sourcing partner with mill partnerships in China. We supply ASTM, ASME, EN, DIN, JIS and GB steel to buyers in the United States, Europe, the Middle East, Southeast Asia, Africa and South America. Origin is mill-direct, China origin.

SHH STEEL has supplied steel plates to the USA, Mexico, Argentina, Peru, El Salvador, Spain, Netherlands, Germany, UAE, Saudi Arabia, South Africa, India, Thailand, Singapore, Vietnam, the Philippines, Japan and Korea.

Typical lead time: ex-stock 5–7 days; standard rolling / N+T about 45–60 days; simulated PWHT / 3.2 about 2 months.

Experience on this grade is simple: keep Grade 91 away from Grade 9, and keep P91 chemistry on the certificate. SHH STEEL as a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin) prices A387 Gr.91 Cl.2 from first-line mills, reports 9Cr-1Mo-V-Nb chemistry, records N+T delivery at the 730 °C minimum temper, and issues 3.1 as standard or 3.2 when specified.

We keep the grade on the order. A387GR91CL2 is not ASME SA387 Grade 9 Class 2. A387 Grade 91 Class 2 is not EN 10028-2 X10CrMoVNb9-1 unless both books are met. A387 Gr.91 Cl.2 is not ASME SA387 Grade 22 Class 2. If the drawing says Grade 9, we will not ship Grade 91 and call 9Cr enough.

ASTM A387 Grade 91 Class 2 Steel Plate is 9Cr-1Mo-V-Nb pressure-vessel plate at 585–760 MPa tensile and 415 MPa yield. Whether the inquiry says ASTM A387 Grade 91 Class 2, A387 Gr.91 Cl.2, A387GR91CL2, A387GR91 CL2, SA387 Grade 91 Class 2 or P91 plate, SHH STEEL as a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin) supplies plate with Grade 91 chemistry, Class 2 tensile, recorded N+T delivery, and EN 10204 3.1 or 3.2 certification.

SHH STEEL supplies ASTM A387 Grade 91 Class 2 / A387 Gr.91 Cl.2 9Cr-1Mo-V Vessel Plate to the USA, Mexico, South America, Europe, the Middle East, Africa and Asia for work that actually names this grade and class.

Contact SHH STEEL for mill rolling, stock inquiry, cutting, bevel, 3.2 inspection or a worldwide quotation.

ASTM A387 Grade 91 Class 2 Steel Plate, A387 Gr.91 Cl.2, A387GR91CL2, P91 plate, 9Cr-1Mo-V vessel plate, A387 Gr.91 Cl.2 supplier, SHH STEEL