Stainless Steel E310Nb PWHT
Heat-treated state
UNS W31017
PWHT = post-weld heat treated
Used for overlays and vessel parts that are re-solution-annealed after welding: lower strength, higher ductility and toughness.
Values for the PWHT condition
Other E310Nb tempers and conditions
E310Nb is listed in 5 conditions; see the grade overview at E310Nb.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
PWHTThis page Post-weld heat treated | Used for overlays and vessel parts that are re-solution-annealed after welding: lower strength, higher ductility and toughness. | 300 | 570 | 42 | 160 HB | 2.2 % IACS |
E310Nb-17 | Choose for the flattest, best-wetting bead on flat/horizontal fillets and sheet; slightly more fluid slag than -16. | 415 | 595 | 30 | 185 HB | 2.2 % IACS |
AWDefault As-welded deposit | Default condition: properties of the undiluted deposit in the as-welded state, as classified by AWS A5.4. | 420 | 600 | 32 | 9 HRC | 2.2 % IACS |
E310Nb-16 | Most widely stocked coating: smooth arc on AC or DC, easy slag release, good bead appearance for general fabrication. | 420 | 600 | 30 | 185 HB | 2.2 % IACS |
E310Nb-15 | Pick for out-of-position work, heavy restraint or maximum weld-metal cleanliness/toughness; DC electrode positive only. | 430 | 610 | 33 | 180 HB | 2.2 % IACS |
What is E310Nb PWHT?
E310Nb PWHT is E310Nb heat treated to PWHT — used for overlays and vessel parts that are re-solution-annealed after welding: lower strength, higher ductility and toughness. E310Nb PWHT has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 68% of stainless steel grades. Elongation at break is 42% and the elastic modulus is 200 GPa (29 Msi). E310Nb 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 — 1,050°C (1,922 °F), better than 91% of stainless steel grades
Limitations
- High embodied carbon — 6 kg CO₂/kg, worse than 88% of stainless steel grades
E310Nb PWHT properties
Typical room-temperature values for E310Nb PWHT; 22 are specific to this condition. Other listed values are E310Nb reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
E310Nb 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).
Mechanical17
E310Nb PWHT has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 68% of stainless steel grades. Elongation at break is 42% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
E310Nb PWHT is rated for continuous service to 1,050°C (1,922 °F). It conducts heat at 14.2 W/m·K (8.2 BTU/hr·ft·°F), worse than 76% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
E310Nb PWHT conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 68% of stainless steel grades.
Sustainability4
Producing a kilogram of E310Nb PWHT takes about 62 MJ of energy and emits 6 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
E310Nb PWHT's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability very good (72/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E310Nb PWHT
Is E310Nb easy to machine?
Weld metal is tough and strongly work-hardening — use rigid setups, positive rake carbide, heavy feeds, low speeds and flood coolant; avoid dwelling.
Can E310Nb be welded?
SMAW with short arc, stringer beads, low heat input and interpass ≤150 °C; fully austenitic deposit is hot-crack prone, so keep dilution low, avoid weaving and re-dry electrodes (250–350 °C) before use.
Can E310Nb be formed, bent or molded?
Deposit is not intended for forming; grinding and light dressing only, expecting high springback and rapid work hardening if cold worked.
What surface finishes work on E310Nb?
Grind/blend with stainless-dedicated abrasives, then pickle and passivate per ASTM A380/A967; electropolishing gives good luster, no anodizing.
E310Nb 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 |
|---|---|---|
| Chigher C than 310L types, intentional for creep strength | ≤ 0.12 | 0.1 |
| Cr | 25 – 28 | 26.5 |
| Ni | 20 – 22 | 21 |
| Mn | 1 – 2.5 | 1.8 |
| Si | ≤ 0.75 | 0.45 |
| NbNb+Ta; carbide stabilizer (formerly written Cb) | 0.7 – 1 | 0.85 |
| Mo | ≤ 0.75 | 0.2 |
| Cu | ≤ 0.75 | 0.15 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Fe | balance | — |
E310Nb PWHT — frequently asked
What is E310Nb PWHT used for?
E310Nb PWHT is typically used for stabilized fully-austenitic overlays, high-temperature fixtures and furnace component repair. In short: nb-stabilized 310 deposit; resists intergranular attack; overlay and repair electrode.
What is the yield strength of E310Nb PWHT?
E310Nb PWHT has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 68% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is E310Nb PWHT easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Weld metal is tough and strongly work-hardening — use rigid setups, positive rake carbide, heavy feeds, low speeds and flood coolant; avoid dwelling.
Can E310Nb PWHT be welded?
Yes — weldability is rated very good (72/100). SMAW with short arc, stringer beads, low heat input and interpass ≤150 °C; fully austenitic deposit is hot-crack prone, so keep dilution low, avoid weaving and re-dry electrodes (250–350 °C) before use.
What surface finishes work on E310Nb PWHT?
Grind/blend with stainless-dedicated abrasives, then pickle and passivate per ASTM A380/A967; electropolishing gives good luster, no anodizing.
Can E310Nb PWHT be formed, bent or molded?
Deposit is not intended for forming; grinding and light dressing only, expecting high springback and rapid work hardening if cold worked.
What is the maximum service temperature of E310Nb PWHT?
E310Nb PWHT is rated for continuous use to about 1,050°C (1,922 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E310Nb-AW and E310Nb PWHT?
AW is the default condition — default condition: properties of the undiluted deposit in the as-welded state, as classified by AWS A5.4. PWHT: used for overlays and vessel parts that are re-solution-annealed after welding: lower strength, higher ductility and toughness. Yield strength is 420 MPa in AW versus 300 MPa in PWHT.
Sources
- AWS A5.4/A5.4M — Specification for Stainless Steel Electrodes for SMAW — 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 consumables — 310-type / 310Nb electrode data — ESAB / Böhler Welding (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.