Stainless Steel E309H PWHT
Heat-treated state
ASTM A5.4
PWHT = post-weld heat treated
Applies when the Cr-Mo or carbon-steel side requires code PWHT; expect carbide precipitation and partial ferrite transformation with a toughness drop.
Values for the PWHT condition
Other E309H tempers and conditions
E309H is listed in 5 conditions; see the grade overview at E309H.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
PWHTThis page Post-weld heat treated | Applies when the Cr-Mo or carbon-steel side requires code PWHT; expect carbide precipitation and partial ferrite transformation with a toughness drop. | 390 | 580 | 30 | 200 HB | 2.3 % IACS |
Long-term service exposure 600–900 °C | Reference condition for fitness-for-service assessment of aged 309H weldments — strength holds up but room-temperature ductility and toughness collapse. | 410 | 620 | 15 | 20 HRC | 2.4 % IACS |
AWDefault As-welded deposit | Default condition for E309H covered electrodes: dissimilar joints, clad restoration and 304H/309H/310H high-temperature service without PWHT. | 420 | 600 | 35 | 190 HB | 2.2 % IACS |
As welded, flux-cored wire deposit | Choose for high deposition rate overlay and position welding of dissimilar/clad joints; toughness is lower than GTAW. | 420 | 590 | 32 | 195 HB | 2.2 % IACS |
AW-GTAW/GMAW | Pick when a clean, low-oxygen deposit with the best toughness and root-pass quality is needed (tube welds, orbital, clad overlay root). | 440 | 620 | 38 | 185 HB | 2.2 % IACS |
What is E309H PWHT?
E309H PWHT is E309H heat treated to PWHT — applies when the Cr-Mo or carbon-steel side requires code PWHT; expect carbide precipitation and partial ferrite transformation with a toughness drop. E309H PWHT has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 54% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 195 GPa (28.3 Msi). E309H PWHT has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F). AW is the default condition FabDigit quotes; PWHT is available on request or by drawing note.
Advantages
- High service temperature — 980°C (1,796 °F), better than 87% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Hard to polish — 55/100, worse than 89% of stainless steel grades
- Low fracture toughness — 85 MPa·√m (77.4 ksi·√in), worse than 77% of stainless steel grades
- Needs corrosion protection — 52/100, worse than 76% of stainless steel grades
E309H PWHT properties
Typical room-temperature values for E309H PWHT; 22 are specific to this condition. Other listed values are E309H reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
E309H PWHT has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
E309H PWHT has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 54% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
E309H PWHT is rated for continuous service to 980°C (1,796 °F). It conducts heat at 15.5 W/m·K (8.96 BTU/hr·ft·°F), better than 53% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
E309H PWHT conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (52/100), worse than 76% of stainless steel grades.
Sustainability4
Producing a kilogram of E309H PWHT takes about 68 MJ of energy and emits 5.2 kg of CO₂ — more than 80% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
E309H PWHT's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability very good (80/100); formability fair (38/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E309H PWHT
Is E309H easy to machine?
Weld deposits machine like Type 309 — gummy and work-hardening; use rigid setups, positive-rake carbide, heavy feeds and flood coolant, and expect ~35 % of 1212 rates.
Can E309H be welded?
Run stringer beads with low heat input, keep interpass below ~150 °C, redry basic electrodes at 300–350 °C, and target 8–15 FN to avoid hot cracking in dilution zones.
Can E309H be formed, bent or molded?
Not a wrought product form; deposited metal tolerates only limited cold straightening because ferrite plus high carbon reduce ductility after thermal exposure.
What surface finishes work on E309H?
Remove slag and heat tint completely, then pickle/passivate (ASTM A380/A967) or blast with stainless grit; do not anodize — carbon steel media contamination causes rust bleeding.
E309H 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 |
|---|---|---|
| Cthe 'H' requirement — raises high-temperature creep strength | 0.04 – 0.15 | 0.1 |
| Cr | 22 – 25 | 23.5 |
| Ni | 12 – 14 | 13 |
| Mn | 0.5 – 2.5 | 1.6 |
| Si0.30–0.65 % for ER309H bare wire per AWS A5.9 | ≤ 0.9 | 0.5 |
| Moresidual | ≤ 0.75 | 0.1 |
| Curesidual | ≤ 0.75 | 0.1 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Fe | balance | — |
E309H PWHT — frequently asked
What is E309H PWHT used for?
E309H PWHT is typically used for high-temperature dissimilar-metal joints, clad overlay on furnace and boiler components, stainless-to-carbon-steel transition welds in hot service, heat-treatment fixture and retort repair, buffer layers under high-temperature surfacing and petrochemical reformer and heater component welds. In short: high-temperature 309 electrode; creep-strength dissimilar filler; service to 980 °C.
What is the yield strength of E309H PWHT?
E309H PWHT has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 54% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is E309H PWHT easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Weld deposits machine like Type 309 — gummy and work-hardening; use rigid setups, positive-rake carbide, heavy feeds and flood coolant, and expect ~35 % of 1212 rates.
Can E309H PWHT be welded?
Yes — weldability is rated very good (80/100). Run stringer beads with low heat input, keep interpass below ~150 °C, redry basic electrodes at 300–350 °C, and target 8–15 FN to avoid hot cracking in dilution zones.
What surface finishes work on E309H PWHT?
Remove slag and heat tint completely, then pickle/passivate (ASTM A380/A967) or blast with stainless grit; do not anodize — carbon steel media contamination causes rust bleeding.
Can E309H PWHT be formed, bent or molded?
Not a wrought product form; deposited metal tolerates only limited cold straightening because ferrite plus high carbon reduce ductility after thermal exposure.
What is the maximum service temperature of E309H PWHT?
E309H PWHT is rated for continuous use to about 980°C (1,796 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E309H-AW and E309H PWHT?
AW is the default condition — default condition for E309H covered electrodes: dissimilar joints, clad restoration and 304H/309H/310H high-temperature service without PWHT. PWHT: applies when the Cr-Mo or carbon-steel side requires code PWHT; expect carbide precipitation and partial ferrite transformation with a toughness drop. Yield strength is 420 MPa in AW versus 390 MPa in PWHT.
Sources
- AWS A5.4/A5.4M — Stainless Steel Electrodes for Shielded Metal Arc Welding — American Welding Society (2012)
- AWS A5.9/A5.9M — Bare Stainless Steel Welding Electrodes and Rods — American Welding Society (2017)
- AWS A5.22 — Stainless Steel Flux Cored and Metal Cored Electrodes — American Welding Society (2012)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering — ASM International (1993)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Stainless SMAW/GTAW consumable datasheets (E309H / ER309H) — 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.