Stainless Steel Haynes 556 HR-A
Finish state
UNS R30556 · ASTM B564/B435
HR-A = hot Rolled + Solution Annealed
Heavy-section plate and forgings; slightly coarser grain and marginally lower strength than thin annealed sheet.
Values for the HR-A condition
Other Haynes 556 tempers and conditions
Haynes 556 is listed in 4 conditions; see the grade overview at Haynes 556.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HR-AThis page Hot Rolled + Solution Annealed | Heavy-section plate and forgings; slightly coarser grain and marginally lower strength than thin annealed sheet. | 390 | 790 | 50 | 10 HRC | 1.8 % IACS |
SADefault Solution Annealed | Standard mill condition for sheet, plate and strip; best combination of ductility, weldability and high-temperature corrosion resistance. | 410 | 815 | 48 | 200 HB | — |
As-welded deposit | Weld-metal / joint condition used for design of fabricated furnace and incinerator components; usually left as-welded without PWHT. | 450 | 770 | 33 | 210 HB | 1.8 % IACS |
Cold worked | Cold-drawn wire, tube or bar where higher room-temperature strength and straightness matter; ductility and high-temperature stability are reduced. | 750 | 1,000 | 18 | 32 HRC | 1.8 % IACS |
What is Haynes 556 HR-A?
Haynes 556 HR-A is Haynes 556 supplied in the HR-A condition — heavy-section plate and forgings; slightly coarser grain and marginally lower strength than thin annealed sheet. Haynes 556 HR-A has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 54% of stainless steel grades. Elongation at break is 50% and the elastic modulus is 205 GPa (29.7 Msi). Haynes 556 HR-A has a density of 8.23 g/cm³ (0.297 lb/in³), heavier than 100% of stainless steel grades. It melts at 1,320°C (2,408 °F). SA is the default condition FabDigit quotes; HR-A is available on request or by drawing note.
Advantages
- High service temperature — 1,100°C (2,012 °F), better than 96% of stainless steel grades
- Ductile — tolerates forming and impact — 50%, better than 90% of stainless steel grades
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
Limitations
- High embodied carbon — 17 kg CO₂/kg, worse than 100% of stainless steel grades
- Difficult to machine — 22/100, worse than 95% of stainless steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades
- Low electrical conductivity — 1.8 % IACS, worse than 87% of stainless steel grades
Haynes 556 HR-A properties
Typical room-temperature values for Haynes 556 HR-A; 23 are specific to this condition. Other listed values are Haynes 556 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
Haynes 556 HR-A has a density of 8.23 g/cm³ (0.297 lb/in³), heavier than 100% of stainless steel grades. It melts at 1,320°C (2,408 °F).
Mechanical13
Haynes 556 HR-A has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 54% of stainless steel grades. Elongation at break is 50% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal5
Haynes 556 HR-A is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades. Thermal expansion is 14.1 µm/m·K (7.83 µin/in·°F).
Electrical3
Haynes 556 HR-A conducts electricity at 1.8 % IACS, worse than 87% of stainless steel grades.
Chemical & Environmental2
Corrosion resistance is very good (78/100), better than 84% of stainless steel grades.
Sustainability3
Producing a kilogram of Haynes 556 HR-A takes about 240 MJ of energy and emits 17 kg of CO₂ — more than 100% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
Haynes 556 HR-A's machinability is poor (22/100, worse than 95% of stainless steel grades); weldability very good (72/100); formability good (58/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Haynes 556 HR-A
Is Haynes 556 easy to machine?
Machine like a solid-solution superalloy: rigid setup, positive rake carbide, low speed / heavy positive feed, flood coolant, avoid dwelling to prevent rapid work hardening.
Can Haynes 556 be welded?
Readily GTAW/GMAW/SMAW-welded with matching 556 filler; keep heat input low, use clean surfaces and no preheat/PWHT for normal sections.
Can Haynes 556 be formed, bent or molded?
Cold formable but springy and fast-work-hardening — allow extra power and intermediate solution anneals at 1175–1205 °C with rapid cooling; hot work 1180–1010 °C.
What surface finishes work on Haynes 556?
Grit blast or pickle to remove Cr-rich scale before service; not anodizable, and coatings are usually unnecessary since the alloy relies on its own protective oxide.
Haynes 556 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cr | 21 – 23 | 22 |
| Ni | 19 – 22.5 | 20 |
| Co | 16 – 21 | 18 |
| Mo | 2.5 – 4 | 3 |
| W | 2 – 3.5 | 2.5 |
| Ta | 0.3 – 1.25 | 0.6 |
| Mn | 0.5 – 2 | 1 |
| Si | 0.2 – 0.8 | 0.4 |
| Al | 0.1 – 0.5 | 0.2 |
| C | 0.05 – 0.15 | 0.1 |
| N | 0.1 – 0.3 | 0.2 |
| Larare-earth addition improving oxide scale adhesion | 0.01 – 0.1 | 0.02 |
| Zr | 0 – 0.1 | 0.02 |
| P | ≤ 0.04 | — |
| S | ≤ 0.02 | — |
| Febalance, nominally ~29 % | balance | — |
Haynes 556 HR-A — frequently asked
What is Haynes 556 HR-A used for?
Haynes 556 HR-A is typically used for waste incineration components, chemical process heaters, gas turbine hardware and industrial furnace fixtures. In short: multi-mode hot corrosion resistance; 1100 °C service ceiling; weldable with matching filler.
What is the yield strength of Haynes 556 HR-A?
Haynes 556 HR-A has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 54% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is Haynes 556 HR-A easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of stainless steel grades). Machine like a solid-solution superalloy: rigid setup, positive rake carbide, low speed / heavy positive feed, flood coolant, avoid dwelling to prevent rapid work hardening.
Can Haynes 556 HR-A be welded?
Yes — weldability is rated very good (72/100). Readily GTAW/GMAW/SMAW-welded with matching 556 filler; keep heat input low, use clean surfaces and no preheat/PWHT for normal sections.
What surface finishes work on Haynes 556 HR-A?
Grit blast or pickle to remove Cr-rich scale before service; not anodizable, and coatings are usually unnecessary since the alloy relies on its own protective oxide.
Can Haynes 556 HR-A be formed, bent or molded?
Cold formable but springy and fast-work-hardening — allow extra power and intermediate solution anneals at 1175–1205 °C with rapid cooling; hot work 1180–1010 °C.
What is the maximum service temperature of Haynes 556 HR-A?
Haynes 556 HR-A is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Haynes 556-SA and Haynes 556-CW?
SA is the default condition — standard mill condition for sheet, plate and strip; best combination of ductility, weldability and high-temperature corrosion resistance. CW: cold-drawn wire, tube or bar where higher room-temperature strength and straightness matter; ductility and high-temperature stability are reduced. Yield strength is 410 MPa in SA versus 750 MPa in CW.
Sources
- HAYNES 556 alloy technical data — Haynes International (2020)
- ASTM B435 — UNS R30556 Sheet, Plate and Strip — ASTM (2019)
- ASTM B572 — UNS R30556 Rod — ASTM (2019)
- ASTM B622 / B626 — seamless and welded tube, UNS R30556 — ASTM (2019)
- ASM Handbook Vol.1 — Heat-Resistant Alloys — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.