Firat Cetin/shutterstock.com
A387 Grade 11 Class 2 – the high-quality chrome moly steel – is used in a wide range of industries and is highly effective, especially in the chemical, oil, and gas industry, where gases and liquids are typically stored at high temperature (see pressure vessels).
In addition, the higher levels of chromium provide excellent resistance against oxidation and corrosion.
Technical specifications are given below for ASTM A387 Grade 11 Class 2.
Chromium & Molybdenum content (according to the ASTM specification):
| Designation |
Nominal Chromium Content (%) |
Nominal Molybdenum Content (%) |
| A387 Grade 11 |
1.25% |
0.50% |
Tensile Requirements for Class 2 Plates
| Designation |
Requirement |
Grade 22 |
| A387 Grade 11 |
Tensile strength, ksi [MPA] |
75 to 100 [515 to 690] |
| |
Yield strength, min, ksi [MPa]/(0.2% offset) |
43 [310] |
| |
Elongation in 8 in. [200 mm], min % |
18 |
| |
Elongation in 2 in. [50 mm], min, % |
22 |
| |
Reduction of area, min % |
|
Chemical Requirements:
| . |
. |
| Carbon (C) |
% |
Heat Analysis:
Product Analysis: |
0.05 - 0.17
0.04 - 0.17 |
| Manganese (Mn) |
% |
Heat Analysis:
Product Analysis: |
0.40 - 0.65
0.35 - 0.73 |
| Phosphorus (P) |
% |
Heat Analysis:
Product Analysis: |
0.035
0.035 |
| Sulphur (S) (Max) |
% |
Heat Analysis:
Product Analysis: |
0.035
0.035 |
| Silicon (Si) |
% |
Heat Analysis:
Product Analysis: |
0.50 - 0.80
0.44 - 0.86 |
| Chromium (Cr) |
% |
Heat Analysis:
Product Analysis: |
1.00 - 1.50
0.94 - 1.56 |
| Molybdenum (Mo) |
% |
Heat Analysis:
Product Analysis: |
0.45 - 0.65
0.45 - 0.70 |
(Maximum values unless stated otherwise)