ASTM A387 Grade 91 is the plate version of the modified 9Cr - 1Mo alloy, strengthened by vanadium, niobium and nitrogen. It permits far thinner vessel walls than Grade 22 at the same temperature, cutting weight and thermal stress in advanced power and petrochemical plant. Normalising and tempering windows are tightly controlled and verified by hardness testing.
Sarovar Tube Industries manufactures, stocks and exports ASTM A387 Grade 91 Sheets & Plates from Mumbai to customers across the Middle East, South East Asia, Europe, Africa and the Americas. Every heat is verified by in-house testing before despatch and supported by complete documentation, so the material you receive is exactly the material you specified.
The table below sets out the standard manufacturing range for ASTM A387 Grade 91 Sheets & Plates. Sizes and finishes outside this range are produced against firm orders.
| Parameter | Details |
|---|---|
| Thickness Range | Sheet 0.5 mm to 5 mm, Plate 5 mm to 150 mm |
| Width | 1000 mm, 1250 mm, 1500 mm, 2000 mm, 2500 mm and custom |
| Length | 2000 mm to 6000 mm, coil and cut-to-size available |
| Form | Hot rolled plate, cold rolled sheet, chequered plate, coil, strip, blanks |
| Surface | Mill finish, 2B, No.4, pickled, shot blasted, painted |
| Edge | Mill edge, trimmed edge, sheared, plasma / laser / waterjet cut |
| Dimensional Standard | ASTM A20 / A480 / EN 10029 as applicable |
| Value Addition | Cutting, bending, rolling, drilling and machining to drawing |
| Description | Details |
|---|---|
| Primary Standard | ASTM A387 / ASME SA387 Grade 91, Class 2 |
| Grade Designation | ASTM A387 Grade 91 |
| Equivalent Grades | UNS K90901, EN 10028-2 X10CrMoVNb9-1, DIN 1.4903 |
| Product Category | Alloy Steel - Sheets & Plates |
| Certification | EN 10204 3.1 as standard, 3.2 with third party inspection on request |
| Thickness (mm) | Standard Width (mm) | Standard Length (mm) | Typical Form |
|---|---|---|---|
| 0.5 - 1.5 | 1000 / 1250 | 2000 / 2500 | Cold rolled sheet |
| 1.6 - 3.0 | 1250 / 1500 | 2500 / 3000 | Sheet / coil |
| 3.1 - 5.0 | 1500 / 2000 | 3000 / 6000 | Sheet / light plate |
| 6 - 12 | 1500 / 2000 | 3000 / 6000 | Hot rolled plate |
| 14 - 25 | 2000 / 2500 | 6000 | Hot rolled plate |
| 26 - 50 | 2000 / 2500 | 6000 | Heavy plate |
| 51 - 100 | 2000 / 2500 | 6000 | Heavy plate |
| 101 - 150 | 2000 / 2500 | 6000 | Heavy plate (on indent) |
Thickness tolerance to EN 10029 or ASTM A20. Cut-to-size pieces and profile cutting supplied against drawings.
Composition limits in weight percent as required by ASTM A387 / ASME SA387 Grade 91, Class 2. Every heat is verified by spectrographic analysis and positive material identification.
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.08 - 0.12 |
| Manganese (Mn) | 0.30 - 0.60 |
| Phosphorus (P) | 0.020 max |
| Sulphur (S) | 0.010 max |
| Silicon (Si) | 0.20 - 0.50 |
| Chromium (Cr) | 8.00 - 9.50 |
| Molybdenum (Mo) | 0.85 - 1.05 |
| Vanadium (V) | 0.18 - 0.25 |
| Niobium (Nb) | 0.06 - 0.10 |
| Nitrogen (N) | 0.030 - 0.070 |
| Nickel (Ni) | 0.40 max |
Minimum room temperature properties in the supplied condition. Results for the actual heat supplied are recorded on the mill test certificate.
| Property | Value |
|---|---|
| Tensile Strength | 585 - 760 MPa |
| Yield Strength | 415 MPa min |
| Elongation in 50 mm | 18% min |
| Hardness | 190 - 250 HB |
| Heat Treatment | Normalise 1040-1080 degrees C, temper 730-800 degrees C |
| Density | 7.76 g/cm3 |
Material is released only after the following checks are completed and recorded:
ASTM A387 Grade 91 Sheets & Plates is specified across the following industries and services:
All material is manufactured and tested to ASTM A387 / ASME SA387 Grade 91, Class 2. Equivalent grades include UNS K90901, EN 10028-2 X10CrMoVNb9-1, DIN 1.4903. The governing standard is printed on every mill test certificate.
Every consignment ships with an EN 10204 3.1 mill test certificate covering heat-wise chemical analysis and mechanical properties. Type 3.2 certification with third party inspection by TUV, SGS, BV or Lloyd's is available when specified at the enquiry stage.
Yes. Beyond the standard range shown above we manufacture to customer drawings and specifications, including special lengths, non-standard wall thickness and machined profiles. Share your drawing with the enquiry and our technical team will confirm feasibility and lead time.
Stock items are despatched within three to five working days of order confirmation. Made-to-order material typically takes four to six weeks depending on grade, size and heat treatment requirements. Export documentation and packing are handled in house.
Custom fabrication, special sizes and complete export documentation are handled in house. Send us your drawing or specification and our technical team will come back with a detailed offer, usually within one working day.