Alloy 304/304H (UNS S30400/ S30409)is a modification of the most widely utilized “18-8” chromium-nickel austenitic stainless steel. The carbon content is controlled in the range of 0.04-0.10% for increased strength at temperatures above 800°F (427°C). It is an economical and versatile corrosion resistant alloy suitable for a wide range of general purpose applications.
It is common practice for 304H to be dual certified as 304 and 304H. The high carbon chemistry of 304H enables 304 to meet the mechanical properties and grain size requirements of 304H.
Alloy 304/304Hhas general corrosion resistance similar to 304/304L. It resists atmospheric corrosion, as well as, moderately oxidizing and reducing environments. However, because of its high carbon content, Alloy 304/304H is subject to carbide precipitation in the heat affected zone of welds.
Alloy 304/304H is non-magnetic in the annealed condition, but can become slightly magnetic as a result of cold working or welding. It can be easily welded and processed by standard shop fabrication practices.
| STANDARDS | |||||
| INDUSTEEL TRADEMARKS | UNS | ASTM | EURONORMS EN | SUS | |
| 304H/304 | S30400/S30409 | 304(H) | 1.4301/1.4948 X5CrNi18-10 | SUS 304 | |
| CHEMICAL ANALYSIS (%WEIGHT) | |||||
| C | Cr | Ni | Mo | N | Others |
| ≥ 0,040 | 18 | 8 | – | – | |
| PROPERTIES | ||||||||||
| 0,2 Y.S. – Rp 0,2min ASTM / EN | 0,2 Y.S. – Rp 0,2(2)typical value | UTS – Rm min ASTM / EN | UTS – Rm(2)typical value | EI-A(1)% | PREN(4) | HOMOLOGATIONS | ||||
| MPa | Ksi | MPa | Ksi | MPa | Ksi | MPa | Ksi | Last revised | ||
| -210 | 30 | 305 | 44 | 520 | 75 | 590 | 86 | 45 | 19 | |
| APPLICATIONS | |||||||||||
| CHEMICAL INDUSTRIES | PROCESS INDUSTRIES | WATER TREATMENT | STORAGE & TRANSPORTATION | ||||||||
| Nitric Acid | Sulfuric Acid | Polymer& otheracids | Fertilisers | Pulp& Paper | Hydrome-tallurgy | Seawater& desalination | Freshwater &Tanks | Waste Water | Chemical Tanks | Cryogenic Tanks | Renewable |
| POWER GENERATION | OIL & GAS | CONSTRUCTION | ||||||
| Nuclear | Pollution control | Hydroelectric | Renewable | Off & Onshore & production | Refining & Gas processing | Petrochemical | Architecture | Bridges |
For more technical details :
(1) Indicative typical values
(2) Indicative typical values for thickness 20 mm at RT for transverse direction
(3) Hardening 496°C (925°F), 4h, air cooling
(4) PREN = Cr + 3.3 Mo + 16N
(5) PRENW = Cr + 3.3(Mo + 0.5W) + 16N
(6) HT: mechanical properties depend on heat treatment
