Stainless Steel E430Nb PWHT
Heat-treated state
UNS W43011
PWHT = post-weld heat treated
Choose when maximum weld ductility, toughness and machinability are required, or when the fabrication code mandates stress relief of ferritic stainless joints.
Values for the PWHT condition
Other E430Nb tempers and conditions
E430Nb is listed in 5 conditions; see the grade overview at E430Nb.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
PWHTThis page Post-weld heat treated | Choose when maximum weld ductility, toughness and machinability are required, or when the fabrication code mandates stress relief of ferritic stainless joints. | 340 | 490 | 28 | 170 HB | 2.9 % IACS |
E430Nb-17 | Higher-silica variant of the -16 coating giving a more fluid slag, flatter bead and better wash-in for flat/horizontal fillet welding. | 415 | 535 | 22 | 197 HB | 2.9 % IACS |
AWDefault As-welded deposit | Default condition for AWS A5.4 classification testing and for most field repairs where PWHT is impractical; preheat 150–250 °C and control interpass to limit grain coarsening. | 420 | 540 | 22 | 14 HRC | 2.9 % IACS |
E430Nb-16 | Most widely stocked type (GB/T 983 E430Nb-16); smooth arc, easy slag release and good bead appearance for general fabrication of stabilized ferritic stainless. | 420 | 540 | 22 | 200 HB | 2.9 % IACS |
E430Nb-15 | Pick for lowest weld-metal hydrogen and best toughness on thick or restrained ferritic sections; DC electrode-positive, all-position, slightly rougher bead. | 430 | 550 | 23 | 200 HB | 2.9 % IACS |
What is E430Nb PWHT?
E430Nb PWHT is E430Nb heat treated to PWHT — choose when maximum weld ductility, toughness and machinability are required, or when the fabrication code mandates stress relief of ferritic stainless joints. E430Nb PWHT has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 28% and the elastic modulus is 200 GPa (29 Msi). E430Nb PWHT has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F). AW is the default condition FabDigit quotes; PWHT is available on request or by drawing note.
Advantages
- Conducts heat well — 25.5 W/m·K (14.7 BTU/hr·ft·°F), better than 95% of stainless steel grades
- Easy to machine — 50/100, better than 90% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- High service temperature — 815°C (1,499 °F), better than 77% of stainless steel grades
Limitations
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 88% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
E430Nb PWHT properties
Typical room-temperature values for E430Nb PWHT; 22 are specific to this condition. Other listed values are E430Nb reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
E430Nb PWHT has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical17
E430Nb PWHT has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 28% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
E430Nb PWHT is rated for continuous service to 815°C (1,499 °F). It conducts heat at 25.5 W/m·K (14.7 BTU/hr·ft·°F), better than 95% of stainless steel grades. Thermal expansion is 10.4 µm/m·K (5.78 µin/in·°F).
Electrical3
E430Nb PWHT conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (53/100), worse than 75% of stainless steel grades.
Sustainability4
Producing a kilogram of E430Nb PWHT takes about 55 MJ of energy and emits 4.2 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 55%.
Manufacturability6
E430Nb PWHT's machinability is fair (50/100, better than 90% of stainless steel grades); weldability good (65/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E430Nb PWHT
Is E430Nb easy to machine?
Machine the deposit after 760–800 °C anneal; use sharp carbide tooling, rigid setup and positive rake as the as-welded ferrite work-hardens and smears.
Can E430Nb be welded?
Preheat 150–250 °C, keep interpass below ~300 °C, use stringer beads and low heat input, redry electrodes 250–300 °C/1 h, then anneal 760–800 °C and air cool where the code allows.
Can E430Nb be formed, bent or molded?
Not a formable product; the weld bead is deposited to shape — avoid heavy peening or cold straightening of as-welded ferritic joints.
What surface finishes work on E430Nb?
Grind or brush with stainless-only abrasives to remove slag and heat tint, then pickle/passivate to restore the passive Cr oxide; the deposit polishes to a finish close to 430 base metal.
E430Nb 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 A5.4 undiluted weld metal | ≤ 0.1 | 0.05 |
| Cr | 15 – 18 | 16.5 |
| Ni | ≤ 0.6 | 0.3 |
| Mo | ≤ 0.75 | 0.2 |
| Mn | ≤ 1 | 0.6 |
| Siupper end for -17 coating | ≤ 0.9 | 0.5 |
| NbNb(+Ta) stabilizer; some producers specify 10×C min | 0.5 – 1.5 | 0.9 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cu | ≤ 0.75 | 0.1 |
| Fe | balance | — |
E430Nb PWHT — frequently asked
What is E430Nb PWHT used for?
E430Nb PWHT is typically used for stabilized ferritic sheet fabrication, automotive exhaust flanges, appliance panel welding and mild chemical exposure equipment. In short: stabilized ferritic electrode; better weld-decay resistance than E430; anneal for best ductility.
What is the yield strength of E430Nb PWHT?
E430Nb PWHT has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 55% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is E430Nb PWHT easy to machine?
Reasonably — machinability is rated fair (50/100, better than 90% of stainless steel grades). Machine the deposit after 760–800 °C anneal; use sharp carbide tooling, rigid setup and positive rake as the as-welded ferrite work-hardens and smears.
Can E430Nb PWHT be welded?
Yes — weldability is rated good (65/100). Preheat 150–250 °C, keep interpass below ~300 °C, use stringer beads and low heat input, redry electrodes 250–300 °C/1 h, then anneal 760–800 °C and air cool where the code allows.
What surface finishes work on E430Nb PWHT?
Grind or brush with stainless-only abrasives to remove slag and heat tint, then pickle/passivate to restore the passive Cr oxide; the deposit polishes to a finish close to 430 base metal.
Can E430Nb PWHT be formed, bent or molded?
Not a formable product; the weld bead is deposited to shape — avoid heavy peening or cold straightening of as-welded ferritic joints.
What is the maximum service temperature of E430Nb PWHT?
E430Nb PWHT is rated for continuous use to about 815°C (1,499 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E430Nb-AW and E430Nb PWHT?
AW is the default condition — default condition for AWS A5.4 classification testing and for most field repairs where PWHT is impractical; preheat 150–250 °C and control interpass to limit grain coarsening. PWHT: choose when maximum weld ductility, toughness and machinability are required, or when the fabrication code mandates stress relief of ferritic stainless joints. Yield strength is 420 MPa in AW versus 340 MPa in PWHT.
Sources
- AWS A5.4/A5.4M — Specification for Stainless Steel Electrodes for Shielded Metal Arc Welding — American Welding Society (2012)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (ferritic stainless welding) — ASM International (1993)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- Stainless covered electrode datasheets (430/430Nb type) — Böhler Welding / ESAB / (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.