Steel ER80S-B8 PWHT
Heat-treated state · default condition
UNS S50480
PWHT = post-weld heat treated
Standard code condition for P9/T9 piping: tempers the martensite to meet AWS A5.28 80 ksi properties with usable toughness.
Values for the PWHT condition
Other ER80S-B8 tempers and conditions
ER80S-B8 is listed in 3 conditions; see the grade overview at ER80S-B8.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
PWHTDefaultThis page Post-weld heat treated | Standard code condition for P9/T9 piping: tempers the martensite to meet AWS A5.28 80 ksi properties with usable toughness. | 490 | 620 | 22 | 16 HRC | — |
Normalized and tempered | Use when the whole fabrication or weld overlay is re-normalized and tempered, giving the most uniform tempered-martensite structure and best creep behaviour. | 500 | 650 | 24 | 17 HRC | — |
As-welded deposit | Pick only for temporary/non-code work or when a later PWHT is guaranteed — untempered martensite is hard, brittle and cold-crack prone. | 720 | 950 | 12 | 40 HRC | — |
What is ER80S-B8 PWHT?
ER80S-B8 PWHT is ER80S-B8 heat treated to PWHT — standard code condition for P9/T9 piping: tempers the martensite to meet AWS A5.28 80 ksi properties with usable toughness. ER80S-B8 PWHT has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 61% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi). ER80S-B8 PWHT has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,420°C (2,588 °F).
Advantages
- High service temperature — 600°C (1,112 °F), better than 98% of steel grades
- Good corrosion resistance — 32/100, better than 96% of steel grades
Limitations
- Low electrical conductivity — 3 % IACS, worse than 91% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Poor heat conductor — 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades
- Difficult to machine — 38/100, worse than 80% of steel grades
ER80S-B8 PWHT properties
Typical room-temperature values for ER80S-B8 PWHT; 14 are specific to this condition. Other listed values are ER80S-B8 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
ER80S-B8 PWHT has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
ER80S-B8 PWHT has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 61% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
ER80S-B8 PWHT is rated for continuous service to 600°C (1,112 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
ER80S-B8 PWHT conducts electricity at 3 % IACS, worse than 91% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (32/100), better than 96% of steel grades.
Sustainability4
Producing a kilogram of ER80S-B8 PWHT takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 35%.
Manufacturability7
ER80S-B8 PWHT's machinability is fair (38/100, worse than 80% of steel grades); weldability good (55/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ER80S-B8 PWHT
Is ER80S-B8 easy to machine?
Machine only after PWHT/tempering; as-deposited martensite at ~40 HRC needs carbide tooling, low speed and rigid setups.
Can ER80S-B8 be welded?
GTAW/GMAW of P9/T9 with 200–300 °C preheat and interpass, low hydrogen practice, slow cooling and mandatory 730–760 °C PWHT to avoid hard, crack-sensitive martensite.
Can ER80S-B8 be formed, bent or molded?
Supplied as drawn wire or straightened cut lengths; the deposit itself is not cold formed — bend fabrication is done on the base pipe before welding.
What surface finishes work on ER80S-B8?
Grind/blast to remove chromium-rich oxide before painting or aluminizing; no anodizing, and passivation is not effective at only 9 % Cr.
ER80S-B8 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 |
|---|---|---|
| CAWS A5.28 max 0.10 | 0.05 – 0.1 | 0.08 |
| Mn | 0.4 – 0.7 | 0.55 |
| Si | 0.2 – 0.5 | 0.35 |
| Cr | 8 – 10.5 | 9 |
| Mo | 0.8 – 1.2 | 1 |
| Ni | ≤ 0.5 | 0.2 |
| Cu | ≤ 0.35 | 0.1 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.03 | 0.01 |
| Other elements, total | ≤ 0.5 | — |
| Fe | balance | — |
ER80S-B8 PWHT — frequently asked
What is ER80S-B8 PWHT used for?
ER80S-B8 PWHT is typically used for P9 piping welds, high-temperature furnace tubing and petrochemical reactor welding. In short: 9Cr-1Mo P9 matching filler; 600 °C creep-resistant deposit; hardest of the B-series wires.
What is the yield strength of ER80S-B8 PWHT?
ER80S-B8 PWHT has a typical yield strength of 490 MPa (71.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 61% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is ER80S-B8 PWHT easy to machine?
Not especially — machinability is rated fair (38/100, worse than 80% of steel grades). Machine only after PWHT/tempering; as-deposited martensite at ~40 HRC needs carbide tooling, low speed and rigid setups.
Can ER80S-B8 PWHT be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW of P9/T9 with 200–300 °C preheat and interpass, low hydrogen practice, slow cooling and mandatory 730–760 °C PWHT to avoid hard, crack-sensitive martensite.
What surface finishes work on ER80S-B8 PWHT?
Grind/blast to remove chromium-rich oxide before painting or aluminizing; no anodizing, and passivation is not effective at only 9 % Cr.
Can ER80S-B8 PWHT be formed, bent or molded?
Supplied as drawn wire or straightened cut lengths; the deposit itself is not cold formed — bend fabrication is done on the base pipe before welding.
What is the maximum service temperature of ER80S-B8 PWHT?
ER80S-B8 PWHT is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ER80S-B8 PWHT and ER80S-B8-AW?
PWHT is the default condition — standard code condition for P9/T9 piping: tempers the martensite to meet AWS A5.28 80 ksi properties with usable toughness. AW: pick only for temporary/non-code work or when a later PWHT is guaranteed — untempered martensite is hard, brittle and cold-crack prone. Yield strength is 490 MPa in PWHT versus 720 MPa in AW.
Sources
- AWS A5.28/A5.28M — Low-Alloy Steel Electrodes and Rods for Gas Shielded Arc Welding — AWS (2020)
- ASME BPVC Section II Part C, SFA-5.28 — ASME (2023)
- ASME BPVC Section II Part D — physical properties of 9Cr-1Mo materials — ASME (2023)
- ASTM A335/A213 — P9/T9 alloy steel pipe and tube — ASTM (2022)
- ASM Handbook Vol.1 — Properties of Cr-Mo Heat-Resistant Steels — ASM International (1990)
- 9Cr-1Mo (ER80S-B8 / ER505) TIG & MIG wire datasheets — Böhler Welding / ESAB / Lincoln Electric (2023)
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.