446
Data verified446 is a high-chromium ferritic heat-resistant grade with outstanding oxidation and sulfidation resistance at high temperature. Room-temperature ductility and toughness are low, so it serves in static furnace hardware rather than structural parts.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.20 |
| Si | ≤1.00 |
| Mn | ≤1.50 |
| P | ≤0.040 |
| S | ≤0.030 |
| Cr | 23.00–27.00 |
| N | ≤0.25 |
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 | 450–620 MPa |
| Density | 7.70 g/cm³ |
| Magnetic | Yes |
| Max scaling temperature | ~1035 °C |
Heat treatment
Anneal 790–870 °C, air cool. Prolonged exposure in the 400–540 °C range causes severe 475 °C embrittlement.
Equivalent grades
| Standard | Designation |
|---|---|
| aisi | 446 |
| jis | SUH446 |
Compare side by side: 446 vs 439
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Furnace parts, annealing boxes, burner nozzles, molten-metal handling, kiln furniture.
Processing: Difficult to form and weld; usually supplied as castings, plate and simple shapes for hot service; handle with care at room temperature due to brittleness.
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Ask for a quotationVisit NasteelSource: ASTM A240 / A276 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.