ASTM A387 Grade 91 Class 2 / ASME SA387 Grade 91 Class 2
In this section:
chrome moly steel |
A387 Grade 11 Class 2 |
A387 Grade 12 Class 2 |
A387 Grade 22 Class 2
A387 Grade 5 Class 2 |
A387 Grade 91 Class 2 |
A387 Grade 9 Class 2

High quality
A387 Grade 91 Class 2 – manufactured at some of the world's finest steel mills, this chrome–molybdenum alloy has excellent resistance to high working temperatures making it ideal for use in the oil, gas, chemical and power generation industry applications.
Our plates can be supplied from our own stockholding or directly from the mill – all plates come with mill test certification and individual stampings. Third party testing can be arranged at the customers request.
ASTM / ASME Specification:
- ASTM A387 Grade 91 Class 2
- ASME SA387 Grade 91 Class 2
Equivalents
| BS |
EN |
ASTM/ASME |
DIN |
| ... |
... |
A387-91-2 |
... |
| |
Specifications
Chromium & Molybdenum content (according to the ASTM specification):
| Designation |
Nominal Chromium Content (%) |
Nominal Molybdenum Content (%) |
| A387 Grade 91 |
9.00% |
1.00% |
| |
Tensile Requirements for Class 2 Plates
| Designation: |
Requirement: |
Grade 91 |
| A387 Grade 91 |
Tensile strength, ksi [MPA] |
85 to 110 [585 to 760] |
| |
| |
Yield strength, min, ksi [MPa]/(0.2% offset) |
60 [415] |
| |
Elongation in 8 in. [200mm], min % |
... |
| |
Elongation in 2 in. [50mm], min, % |
18 |
| |
Reduction of area, min % |
... |
| |
Chemical Requirements
| Element |
|
Chemical Composition (%) inc. Grade & UNS No. |
| |
|
Grade 91 (UNS: S50200) |
| Carbon: |
|
|
| |
Heat Analysis: |
0.08 - 0.12 |
| |
Product Analysis: |
0.06 - 0.15 |
| Manganese: |
|
|
| |
Heat Analysis: |
0.30 - 0.60 |
| |
Product Analysis: |
0.25 - 0.66 |
| Phosphorus: |
|
|
| |
Heat Analysis: |
0.020 |
| |
Product Analysis: |
0.025 |
| Sulphur (max): |
|
|
| |
Heat Analysis: |
0.010 |
| |
Product Analysis: |
0.012 |
| Silicon: |
|
|
| |
Heat Analysis: |
0.20 - 0.50 |
| |
Product Analysis: |
0.18 - 0.56 |
| Chromium: |
|
|
| |
Heat Analysis: |
8.00 - 9.50 |
| |
Product Analysis: |
7.90 - 9.60 |
| Molybdenum: |
|
|
| |
Heat Analysis: |
0.85 - 1.05 |
| |
Product Analysis: |
0.80 - 1.10 |
| Nickel, max: |
|
|
| |
Heat Analysis: |
0.40 |
| |
Product Analysis: |
0.43 |
| Vanadium: |
|
|
| |
Heat Analysis: |
0.18 - 0.25 |
| |
Product Analysis: |
0.16 - 0.27 |
| Columbium: |
|
|
| |
Heat Analysis: |
0.06 - 0.10 |
| |
Product Analysis: |
0.05 - 0.11 |
| Nitrogen: |
|
|
| |
Heat Analysis: |
0.030 - 0.070 |
| |
Product Analysis: |
0.025 - 0.080 |
| Aluminum: |
|
|
| |
Heat Analysis: |
0.02 |
| |
Product Analysis: |
0.02 |
| Titanium: |
|
|
| |
Heat Analysis: |
0.01 |
| |
Product Analysis: |
0.01 |
| Zirconium: |
|
|
| |
Heat Analysis: |
0.01 |
| |
Product Analysis: |
0.01 |
| |
Tension Test Requirements:
The material shall be tested using a test specimen will confirm to the tensile requirements as outlined in Table 2.
Other requirements:
The following requirements and testing procedures (which are not mandatory) are considered suitable for Chrome Molybdenum steel:
- Vacuum treatment
- Product Analysis
- Additional Tension Test
- Charpy V-Notch Impact Test
- Drop Weight Test
- High Temperature Tension Test
- Ultrasonic Examination
- Magnetic Particle Examination
To find out more about Masteel's services and ASTM A387 Grade 12 Class 2 steel plates which we can supply directly to you from stock or from the mill, click
here to contact us.
Steel Product Range:
pressure vessel steel |
boiler plate |
chrome moly steel |
clad plates |
structural steel |
hic steel
wear resistant steel |
stainless steel |
heat resistant steel |
structural steel sections |
pipes/tubulars
hot rolled plate |
weather resistant steel
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