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Topics Covered
Background
Chromium-Molybdenum Alloy - A387
Grade 91 Class 2
Different Grades of ASTM / ASME Grade 91
Chromium-Molybdenum Alloy
Equivalent Grade of A387 Grade 91
Chromium-Molybdenum Alloy
Chromium and Molybdenum
Composition of A387 Grade 91 Chromium-Molybdenum Alloy
Tensile Requirements for A387 Grade 91 Chrome Molybdenum Class 2
Plates
Chemical Composition of A387 Grade 91
Chromium-Molybdenum Alloy
Tensile Test Requirements for
Chrome Molybdenum Steel
Recommended Testing Procedures for
Chrome Molybdenum Steel
Background
Masteel UK
Ltd are a global steel supply and stockholding company, supplying the
engineering, power generation, petrochemical, oil and gas and nuclear
industries.
Partnerships integrating the resources of the worlds most technically
advanced steel mills enable Masteel to provide a single competitive source for the
distribution of steel products worldwide,
Chromium-Molybdenum Alloy - A387 Grade 91 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.
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Different Grades of ASTM / ASME Grade 91 Chromium-Molybdenum Alloy
Masteel's range of ASTM / ASME A387
Grade 91 chromium-molybdenum alloy products are available in different
grades listed in the following.
- ASTM A387 Grade 91 Class 2
- ASME SA387 Grade 91 Class 2
Equivalent Grade of A387 Grade 91 Chromium-Molybdenum Alloy
The equivalent grade of A387 Grade 91 chromium-molybdenum alloy is as follows:
|
BS |
EN |
ASTEM/ASME |
DIN |
|
- |
- |
A387-91-2 |
- |
Chromium and Molybdenum Composition of A387 Grade 91 Chromium-Molybdenum
Alloy
The chromium
and molybdenum contents of A387 Grade 91
chromium-molybdenum alloy (according to the ASTM
specification) are outlined in the following table.
|
Designation |
Nominal Chromium Content
(%) |
Nominal Molybdenum Content
(%) |
|
A387 Grade 91 |
9.00% |
1.00% |
Tensile Requirements for A387 Grade 91 Chrome Molybdenum Class 2 Plates
The tensile requirements for A387 Grade 91
chromium-molybdenum alloy Class 2 Plates are listed in the following table.
|
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 Composition of A387 Grade 91 Chromium-Molybdenum Alloy
The chemical composition of A387 Grade 91
chromium-molybdenum alloy from heat and product analysis is
summarised in the following table.
|
Element |
Analysis |
Chemical Composition (%) inc. Grade & UNS
No. |
| |
|
Grade 91 (UNS: S50200) |
|
Carbon: |
Heat Analysis:
Product Analysis: |
0.08 - 0.12
0.06 - 0.15 |
|
Manganese: |
Heat Analysis:
Product Analysis: |
0.30 - 0.60
0.25 - 0.66
|
|
Phosphorus: |
Heat Analysis:
Product Analysis: |
0.020
0.025
|
|
Sulphur (max): |
Heat Analysis:
Product Analysis: |
0.012
0.010
|
|
Silicon: |
Heat Analysis:
Product Analysis: |
0.20 - 0.50
0.18 - 0.56 |
|
Chromium: |
Heat Analysis:
Product Analysis: |
8.00 - 9.50
7.90 - 9.60
|
|
Molybdenum: |
Heat Analysis:
Product Analysis: |
0.85 - 1.05
0.80 - 1.10
|
|
Nickel, max: |
Heat Analysis:
Product Analysis: |
0.40
0.43 |
|
Vanadium: |
Heat Analysis:
Product Analysis: |
0.18 - 0.25
0.16 - 0.27
|
|
Columbium: |
Heat Analysis:
Product Analysis: |
0.06 - 0.10
0.05 - 0.11
|
|
Nitrogen: |
Heat Analysis:
Product Analysis: |
0.030 - 0.070
0.025 - 0.080
|
|
Aluminum: |
Heat Analysis:
Product Analysis: |
0.02
0.02 |
|
Titanium: |
Heat Analysis:
Product Analysis: |
0.01
0.01 |
|
Zirconium: |
Heat Analysis:
Product Analysis: |
0.01
0.01 |
Tensile Test Requirements for Chromium-Molybdenum Alloy
The material shall be tested using a test specimen will confirm to the
tensile requirements as outlined in tensile requirements for A387 Grade 91
chromium-molybdenum alloy Class 2 Plates above.
Recommended Testing Procedures for Chromium-Molybdenum Alloy
The following requirements and testing procedures (which are not mandatory)
are considered suitable for chromium-molybdenum alloy:
- 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 91
Class 2 steel plates which we can supply directly to you please visit Masteel.
Source: Masteel UK Ltd.
For more information on this source please visit Masteel
UK Ltd.