A lower carbon variant of Grade 304, Type 304L steel can be welded without the resulting problem of carbon precipitation (precipitation of chromium carbide when heat is applied during the welding procedure which depletes the steel’s chromium element thereby reducing its anti-corrosive/oxidation effectiveness).
Therefore, Type 304L stainless steel is a highly popular material for use in highly corrosive conditions. Weld annealing is only required in those applications where there are excessive stress loads.
This steel Grade is found in many different commercial industries, especially in the chemical sector.
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Benefits of using 304L Stainless Steel
- Can be used in highly corrosive environments
- Low carbon content removes carbon precipitation in the welding process
- Weld annealing only needed in high stress applications
- Extremely similar to Type 304
304 & 304L plate and pipes exhibit similar properties and in some cases are stocked with Dual Certification, where it is concluded that each item has a composition and properties which conform to both types of steel., It is not possible to include Grade 304H in this equation because of the steel’s higher carbon content which is meant for use in high temperature applications
Mechanical Properties of 304L
| Description |
Type 304L |
| Proof Stress 0.2% (MPa) |
170 |
| Tensile strength (MPa) |
485 |
| Elongation A5 (%) |
40 |
| Hardness |
HB: 201
HRB: 92 |
Chemical Composition of 304L
| . |
. |
| UNS No |
S30403 |
| EN |
1.4301 |
| AISI |
304 |
| Carbon (C) |
0.03 |
| Silicon (Si) |
0.75 |
| Manganese (Mn) |
2.00 |
| Phosphorus (P) |
0.045 |
| Sulphur (S) |
0.030 |
| Chromium (Cr) |
18.00 - 20.00 |
| Molybdenum (Mo) |
|
| Nickel (Ni) |
8.00 - 12.00 |
| Nitrogen (N) |
0.10 |