Steel ER80S-B6 PWHT745
Heat-treated state · default condition
UNS S50280
PWHT745 = pWHT 745 °C
Standard code condition for P5 piping and pressure parts — tempers the martensite to give the classified 80 ksi properties with good toughness and hardness below 225 HB.
Values for the PWHT745 condition
Other ER80S-B6 tempers and conditions
ER80S-B6 is listed in 3 conditions; see the grade overview at ER80S-B6.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
PWHT745DefaultThis page PWHT 745 °C | Standard code condition for P5 piping and pressure parts — tempers the martensite to give the classified 80 ksi properties with good toughness and hardness below 225 HB. | 505 | 620 | 22 | 200 HB | — |
SR 705 °C | Choose when higher joint strength is needed and the code allows the lower end of the P5 PWHT band; toughness is lower than a full 745 °C temper. | 570 | 690 | 19 | 22 HRC | — |
As-welded deposit | Only for temporary/non-code work or hardfacing-type build-up; deposit is hard untempered martensite with low toughness and cracking risk. | 640 | 790 | 14 | 36 HRC | — |
What is ER80S-B6 PWHT745?
ER80S-B6 PWHT745 is ER80S-B6 heat treated to PWHT745 — standard code condition for P5 piping and pressure parts — tempers the martensite to give the classified 80 ksi properties with good toughness and hardness below 225 HB. ER80S-B6 PWHT745 has a yield strength of 505 MPa (73.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 64% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi). ER80S-B6 PWHT745 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% 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 — 30/100, better than 95% of steel grades
Limitations
- Low electrical conductivity — 3.2 % IACS, worse than 87% of steel grades
ER80S-B6 PWHT745 properties
Typical room-temperature values for ER80S-B6 PWHT745; 14 are specific to this condition. Other listed values are ER80S-B6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
ER80S-B6 PWHT745 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
ER80S-B6 PWHT745 has a yield strength of 505 MPa (73.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 64% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
ER80S-B6 PWHT745 is rated for continuous service to 600°C (1,112 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 73% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
ER80S-B6 PWHT745 conducts electricity at 3.2 % IACS, worse than 87% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 95% of steel grades.
Sustainability4
Producing a kilogram of ER80S-B6 PWHT745 takes about 32 MJ of energy and emits 2.4 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 35%.
Manufacturability7
ER80S-B6 PWHT745's machinability is fair (45/100, worse than 65% of steel grades); weldability very good (70/100); 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-B6 PWHT745
Is ER80S-B6 easy to machine?
Machine after PWHT (≤225 HB) with carbide tooling and rigid setups; as-welded martensite at 35+ HRC needs grinding rather than turning.
Can ER80S-B6 be welded?
GMAW/GTAW/SAW with Ar-based shielding; preheat 200–300 °C, interpass ≤350 °C, slow cool and PWHT at 730–760 °C, and keep the wire and joint dry to avoid hydrogen cracking.
Can ER80S-B6 be formed, bent or molded?
Supplied only as drawn/copper-free bright wire — no forming of the deposit; avoid cold straightening of un-tempered welds.
What surface finishes work on ER80S-B6?
Wire-brush or pickle the Cr-rich oxide film before painting; aluminizing or high-temperature silicone-aluminium paint is used for hot exterior service.
ER80S-B6 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 | ≤ 0.1 | 0.07 |
| Mn | 0.4 – 0.7 | 0.55 |
| Si | 0.05 – 0.5 | 0.35 |
| Cr | 4.5 – 6 | 5.2 |
| Mo | 0.45 – 0.65 | 0.55 |
| Niresidual | ≤ 0.6 | 0.1 |
| Cuincludes any coating | ≤ 0.35 | 0.1 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.03 | 0.01 |
| Vresidual, part of total-others limit | ≤ 0.05 | 0.01 |
| Fe | balance | — |
ER80S-B6 PWHT745 — frequently asked
What is ER80S-B6 PWHT745 used for?
ER80S-B6 PWHT745 is typically used for P5 alloy piping welds, refinery furnace tube welding and high-temperature corrosion resistant piping. In short: 5Cr-0.5Mo P5 matching filler; 600 °C service capability; PWHT-mandatory martensitic deposit.
What is the yield strength of ER80S-B6 PWHT745?
ER80S-B6 PWHT745 has a typical yield strength of 505 MPa (73.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 64% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is ER80S-B6 PWHT745 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine after PWHT (≤225 HB) with carbide tooling and rigid setups; as-welded martensite at 35+ HRC needs grinding rather than turning.
Can ER80S-B6 PWHT745 be welded?
Yes — weldability is rated very good (70/100). GMAW/GTAW/SAW with Ar-based shielding; preheat 200–300 °C, interpass ≤350 °C, slow cool and PWHT at 730–760 °C, and keep the wire and joint dry to avoid hydrogen cracking.
What surface finishes work on ER80S-B6 PWHT745?
Wire-brush or pickle the Cr-rich oxide film before painting; aluminizing or high-temperature silicone-aluminium paint is used for hot exterior service.
Can ER80S-B6 PWHT745 be formed, bent or molded?
Supplied only as drawn/copper-free bright wire — no forming of the deposit; avoid cold straightening of un-tempered welds.
What is the maximum service temperature of ER80S-B6 PWHT745?
ER80S-B6 PWHT745 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-B6 PWHT745 and ER80S-B6-AW?
PWHT745 is the default condition — standard code condition for P5 piping and pressure parts — tempers the martensite to give the classified 80 ksi properties with good toughness and hardness below 225 HB. AW: only for temporary/non-code work or hardfacing-type build-up; deposit is hard untempered martensite with low toughness and cracking risk. Yield strength is 505 MPa in PWHT745 versus 640 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 — Properties (5Cr-0.5Mo) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (Cr-Mo steels) — ASM International (1993)
- 5Cr-0.5Mo solid welding wire datasheets (Lincoln, ESAB, Böhler, / ) — various (2024)
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.