321H
Data verified321H is the high-carbon, titanium-stabilised variant of 321, combining sensitisation resistance with guaranteed creep strength for high-temperature pressure parts. It is used in boiler and refinery service where plain 321 lacks code strength values.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.04–0.10 |
| Si | ≤0.75 |
| Mn | ≤2.00 |
| P | ≤0.045 |
| S | ≤0.030 |
| Cr | 17.00–19.00 |
| Ni | 9.00–12.00 |
| Ti | 4×(C+N)–0.70 |
| N | ≤0.10 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Hardness | ≤217 HB (annealed) |
| Tensile strength | 515–690 MPa |
| Density | 7.90 g/cm³ |
| Creep service | Rated for pressure service above ~525 °C |
Heat treatment
Solution anneal 1040–1120 °C, rapid cool.
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.4878 |
| aisi | 321H |
| jis | SUS321 |
| gb | 07Cr19Ni11Ti |
Compare side by side: 321H vs 321 · 321H vs 347H
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Superheater tubes, high-temperature pressure piping, refinery headers, heat-exchanger shells.
Processing: Weldable with stabilised fillers; creep design values are taken from the pressure codes rather than room-temperature data.
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Ask for a quotationVisit NasteelSource: ASTM A240 / A312 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.