Steel E80C-B6 PWHT-730
Heat-treated state
PWHT-730 = pWHT 730–760 °C
Field/shop PWHT window used on ASTM A335 P5 and A387 Gr.5 joints; slightly softer and tougher than the 745 °C classification test.
Values for the PWHT-730 condition
Other E80C-B6 tempers and conditions
E80C-B6 is listed in 4 conditions; see the grade overview at E80C-B6.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Thermomechanically controlled processed | Same alloy tested under 75–80 % Ar / balance CO₂ shielding; lower spatter, slightly higher toughness and silicon recovery than the CO₂-shielded version. | 505 | 600 | 23 | 190 HB | 2.9 % IACS |
PWHT-745Default PWHT | Standard delivered/qualified condition — use for all pressure-boundary 5Cr-0.5Mo joints; restores ductility and toughness of the martensitic weld metal. | 510 | 600 | 22 | 195 HB | — |
PWHT-730This page PWHT 730–760 °C | Field/shop PWHT window used on ASTM A335 P5 and A387 Gr.5 joints; slightly softer and tougher than the 745 °C classification test. | 520 | 620 | 21 | 16 HRC | 2.9 % IACS |
As-welded deposit | Only for non-code, non-pressure or temporary work — weld metal is untempered martensite with high hardness, very low toughness and cold-cracking risk. | 680 | 850 | 12 | 38 HRC | 2.8 % IACS |
What is E80C-B6 PWHT-730?
E80C-B6 PWHT-730 is E80C-B6 heat treated to PWHT-730 — field/shop PWHT window used on ASTM A335 P5 and A387 Gr.5 joints; slightly softer and tougher than the 745 °C classification test. E80C-B6 PWHT-730 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 67% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi). E80C-B6 PWHT-730 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). PWHT-745 is the default condition FabDigit quotes; PWHT-730 is available on request or by drawing note.
Advantages
- High service temperature — 600°C (1,112 °F), better than 98% of steel grades
- Good corrosion resistance — 25/100, better than 92% of steel grades
Limitations
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Poor heat conductor — 27 W/m·K (15.6 BTU/hr·ft·°F), worse than 86% of steel grades
E80C-B6 PWHT-730 properties
Typical room-temperature values for E80C-B6 PWHT-730; 23 are specific to this condition. Other listed values are E80C-B6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
E80C-B6 PWHT-730 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).
Mechanical14
E80C-B6 PWHT-730 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 67% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
E80C-B6 PWHT-730 is rated for continuous service to 600°C (1,112 °F). It conducts heat at 27 W/m·K (15.6 BTU/hr·ft·°F), worse than 86% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical2
E80C-B6 PWHT-730 has an electrical resistivity of 6×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of E80C-B6 PWHT-730 takes about 33 MJ of energy and emits 2.6 kg of CO₂ — more than 76% of steel grades. Typical recycled content is 25%.
Manufacturability6
E80C-B6 PWHT-730's machinability is fair (42/100, worse than 73% of steel grades); weldability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E80C-B6 PWHT-730
Is E80C-B6 easy to machine?
Machine only after PWHT; as-welded deposit at 35–45 HRC needs carbide or CBN tooling and rigid setups.
Can E80C-B6 be welded?
GMAW/FCAW with Ar-CO₂ or CO₂ shielding; preheat 200–300 °C, interpass ≤ 350 °C, slow cool and PWHT 730–760 °C within a few hours to avoid hydrogen cracking.
Can E80C-B6 be formed, bent or molded?
Not a wrought product — deposit is applied as weld beads; keep heat input moderate (≈ 0.8–2.0 kJ/mm) to limit coarse martensite.
What surface finishes work on E80C-B6?
Grind or blast weld surfaces and apply high-temperature aluminum silicone paint or aluminized coating; the 5Cr deposit is not corrosion-resistant at ambient conditions.
E80C-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 |
|---|---|---|
| Cdeposited weld metal, AWS A5.29 | 0.05 – 0.12 | 0.08 |
| Mn | ≤ 1.25 | 0.6 |
| Si | ≤ 0.8 | 0.4 |
| Cr | 4 – 6 | 5 |
| Mo | 0.45 – 0.65 | 0.55 |
| Ni | ≤ 0.4 | 0.1 |
| Vresidual limit | ≤ 0.05 | 0.02 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.03 | 0.01 |
| Curesidual limit | ≤ 0.35 | 0.05 |
| Fe | balance | — |
E80C-B6 PWHT-730 — frequently asked
What is E80C-B6 PWHT-730 used for?
E80C-B6 PWHT-730 is typically used for 5Cr-0.5Mo piping, refinery furnace tubes, high-temperature process equipment and hydroprocessing units. In short: 5Cr creep-resistant deposit; mandatory 730–760 °C PWHT; matches P5 piping.
What is the yield strength of E80C-B6 PWHT-730?
E80C-B6 PWHT-730 has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is E80C-B6 PWHT-730 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine only after PWHT; as-welded deposit at 35–45 HRC needs carbide or CBN tooling and rigid setups.
Can E80C-B6 PWHT-730 be welded?
With care — weldability is rated fair (45/100). GMAW/FCAW with Ar-CO₂ or CO₂ shielding; preheat 200–300 °C, interpass ≤ 350 °C, slow cool and PWHT 730–760 °C within a few hours to avoid hydrogen cracking.
What surface finishes work on E80C-B6 PWHT-730?
Grind or blast weld surfaces and apply high-temperature aluminum silicone paint or aluminized coating; the 5Cr deposit is not corrosion-resistant at ambient conditions.
Can E80C-B6 PWHT-730 be formed, bent or molded?
Not a wrought product — deposit is applied as weld beads; keep heat input moderate (≈ 0.8–2.0 kJ/mm) to limit coarse martensite.
What is the maximum service temperature of E80C-B6 PWHT-730?
E80C-B6 PWHT-730 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 E80C-B6 PWHT-745 and E80C-B6-AW?
PWHT-745 is the default condition — standard delivered/qualified condition — use for all pressure-boundary 5Cr-0.5Mo joints; restores ductility and toughness of the martensitic weld metal. AW: only for non-code, non-pressure or temporary work — weld metal is untempered martensite with high hardness, very low toughness and cold-cracking risk. Yield strength is 510 MPa in PWHT-745 versus 680 MPa in AW.
Sources
- AWS A5.29/A5.29M — Low-Alloy Steel Electrodes for Flux Cored Arc Welding — American Welding Society (2010)
- ASME BPVC Section II Part C — Welding Rods, Electrodes and Filler Metals (SFA-5.29) — ASME (2023)
- ASME BPVC Section II Part D — Properties (5Cr-0.5Mo materials) — ASME (2023)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (Cr-Mo steel welding) — ASM International (1993)
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.