Stainless Steel E309Mo-AW (As-welded deposit)
Heat-treated state · default condition
UNS W30920 · ASTM A5.4
Standard qualification/service condition for E309Mo electrodes; use for dissimilar joints and 316-type overlay buffer layers.
Values for the AW condition
Other E309Mo tempers and conditions
E309Mo is listed in 3 conditions; see the grade overview at E309Mo.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed (~1050 °C + rapid cool) weld deposit | Only for weldments (e.g. clad or overlaid components) that are solution annealed as a whole to restore corrosion resistance and ductility. | 350 | 570 | 38 | 175 HB | 2.3 % IACS |
Post-weld heat treated | Used when the carbon-steel side of a dissimilar joint mandates code stress relief; accept lower toughness and sensitisation risk. | 430 | 590 | 28 | 195 HB | 2.3 % IACS |
AWDefaultThis page As-welded deposit | Standard qualification/service condition for E309Mo electrodes; use for dissimilar joints and 316-type overlay buffer layers. | 450 | 600 | 32 | 200 HB | 2.2 % IACS |
What is E309Mo-AW?
E309Mo-AW is E309Mo heat treated to AW — standard qualification/service condition for E309Mo electrodes; use for dissimilar joints and 316-type overlay buffer layers. E309Mo-AW has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 70% of stainless steel grades. Elongation at break is 32% and the elastic modulus is 196 GPa (28.4 Msi). E309Mo-AW 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).
Advantages
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Hard to polish — 60/100, worse than 80% of stainless steel grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 77% of stainless steel grades
E309Mo-AW properties
Typical room-temperature values for E309Mo-AW; 23 are specific to this condition. Other listed values are E309Mo reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
E309Mo-AW 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
E309Mo-AW has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 70% of stainless steel grades. Elongation at break is 32% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
E309Mo-AW is rated for continuous service to 750°C (1,382 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 59% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
E309Mo-AW conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (66/100), better than 59% of stainless steel grades.
Sustainability4
Producing a kilogram of E309Mo-AW takes about 60 MJ of energy and emits 5.5 kg of CO₂ — more than 70% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
E309Mo-AW's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability very good (80/100); formability fair (40/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E309Mo-AW
Is E309Mo easy to machine?
Weld deposit machines like 316-type stainless: low speeds, positive-rake sharp carbide, heavy rigid setup and flood coolant to fight work hardening and gumminess.
Can E309Mo be welded?
SMAW with DCEP (E309Mo-15/-16 also run AC for -16); redry electrodes 250–300 °C, keep interpass below ~150 °C on dissimilar joints, use stringer beads and maintain 10–20 FN ferrite to avoid hot cracking.
Can E309Mo be formed, bent or molded?
Not a wrought product — deposit geometry is set by bead placement; buffer layers of 2–3 mm are typical before depositing 316-type surfacing.
What surface finishes work on E309Mo?
Remove slag fully between passes, then pickle/passivate or blast-and-brush with stainless tooling; do not anodise, and avoid carbon-steel wire brushes that cause iron contamination.
E309Mo 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 |
|---|---|---|
| Cstandard carbon (vs 0.04 max for E309LMo) | ≤ 0.12 | 0.06 |
| Cr | 22 – 25 | 23.5 |
| Ni | 12 – 14 | 13 |
| Mo | 2 – 3 | 2.5 |
| Mn | 0.5 – 2.5 | 1.5 |
| Si | ≤ 0.9 | 0.6 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cu | ≤ 0.75 | 0.1 |
| Febalance, undiluted weld metal | balance | — |
E309Mo-AW — frequently asked
What is E309Mo-AW used for?
E309Mo-AW is typically used for dissimilar metal welding with Mo-bearing base metals, overlay cladding and process equipment fabrication. In short: standard-carbon 309Mo electrode; buffer layer for 316 overlay; higher strength than E309LMo.
What is the yield strength of E309Mo-AW?
E309Mo-AW has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 70% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is E309Mo-AW easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Weld deposit machines like 316-type stainless: low speeds, positive-rake sharp carbide, heavy rigid setup and flood coolant to fight work hardening and gumminess.
Can E309Mo-AW be welded?
Yes — weldability is rated very good (80/100). SMAW with DCEP (E309Mo-15/-16 also run AC for -16); redry electrodes 250–300 °C, keep interpass below ~150 °C on dissimilar joints, use stringer beads and maintain 10–20 FN ferrite to avoid hot cracking.
What surface finishes work on E309Mo-AW?
Remove slag fully between passes, then pickle/passivate or blast-and-brush with stainless tooling; do not anodise, and avoid carbon-steel wire brushes that cause iron contamination.
Can E309Mo-AW be formed, bent or molded?
Not a wrought product — deposit geometry is set by bead placement; buffer layers of 2–3 mm are typical before depositing 316-type surfacing.
What is the maximum service temperature of E309Mo-AW?
E309Mo-AW is rated for continuous use to about 750°C (1,382 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E309Mo-AW and E309Mo SOL-ANN?
AW is the default condition — standard qualification/service condition for E309Mo electrodes; use for dissimilar joints and 316-type overlay buffer layers. SOL-ANN: only for weldments (e.g. clad or overlaid components) that are solution annealed as a whole to restore corrosion resistance and ductility. Yield strength is 450 MPa in AW versus 350 MPa in SOL-ANN.
Sources
- AWS A5.4/A5.4M — Stainless Steel Electrodes for Shielded Metal Arc Welding — 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)
- 309Mo-type covered electrode datasheets (Böhler, ESAB, Lincoln Electric) — voestalpine 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.