Stainless Steel E309LMo-AW (As-welded deposit)
Heat-treated state · default condition
UNS W30923 · ASTM A5.4
Default condition for dissimilar joints and buttering layers; deposit used directly after welding with 8–20 FN ferrite.
Values for the AW condition
Other E309LMo tempers and conditions
E309LMo is listed in 5 conditions; see the grade overview at E309LMo.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Silica-boosted rutile coating, AC or DCEP | Choose for the flattest, best-wetting bead on flat/horizontal fillets and overlay; more fluid slag than -16, slightly softer arc. | 420 | 590 | 38 | 185 HB | 2.2 % IACS |
AWDefaultThis page As-welded deposit | Default condition for dissimilar joints and buttering layers; deposit used directly after welding with 8–20 FN ferrite. | 430 | 600 | 36 | 190 HB | 2.2 % IACS |
Titania (rutile) coating, AC or DCEP | Most widely stocked coating type: smooth arc, easy slag removal, AC/DC operation for general shop and site welding. | 430 | 600 | 36 | 190 HB | 2.2 % IACS |
Post-weld heat treated | Applies when the C-steel/low-alloy component must be stress relieved; expect some ferrite transformation, slight strength gain and toughness loss. | 440 | 610 | 30 | 200 HB | 2.2 % IACS |
Lime (basic) coating, DCEP only | Pick for out-of-position work and where the cleanest, lowest-hydrogen, toughest deposit is required; DC electrode positive only. | 450 | 610 | 35 | 195 HB | 2.2 % IACS |
What is E309LMo-AW?
E309LMo-AW is E309LMo heat treated to AW — default condition for dissimilar joints and buttering layers; deposit used directly after welding with 8–20 FN ferrite. E309LMo-AW has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 36% and the elastic modulus is 197 GPa (28.6 Msi). E309LMo-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 — 90/100, better than 95% of stainless steel grades
Limitations
- Hard to polish — 55/100, worse than 89% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
E309LMo-AW properties
Typical room-temperature values for E309LMo-AW; 23 are specific to this condition. Other listed values are E309LMo reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
E309LMo-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
E309LMo-AW has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 36% and the elastic modulus is 197 GPa (28.6 Msi).
Thermal6
E309LMo-AW is rated for continuous service to 400°C (752 °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
E309LMo-AW conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 73% of stainless steel grades.
Sustainability4
Producing a kilogram of E309LMo-AW takes about 55 MJ of energy and emits 5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 60%.
Manufacturability6
E309LMo-AW's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability excellent (90/100); 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 E309LMo-AW
Is E309LMo easy to machine?
Weld deposit machines like 316L — gummy and strongly work-hardening; use sharp carbide, positive rake, heavy feed and flood coolant, avoid dwelling.
Can E309LMo be welded?
SMAW with DCEP (AC also for -16/-17), short arc, stringer beads, interpass ≤150 °C; redry electrodes ~250–300 °C/1 h and keep ferrite 8–20 FN to avoid hot cracking.
Can E309LMo be formed, bent or molded?
Not a wrought product; deposited overlay can be lightly ground/peened but not cold formed as such.
What surface finishes work on E309LMo?
Grind, pickle (HNO₃-HF paste) and passivate the deposit to restore the passive film; deposit is weakly magnetic so magnetic-particle testing is unreliable — use PT/UT.
E309LMo 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 |
|---|---|---|
| Clow-carbon 'L' grade | ≤ 0.04 | 0.03 |
| Cr | 22 – 25 | 23.5 |
| Ni | 12 – 14 | 13 |
| Mo | 2 – 3 | 2.5 |
| Mn | 0.5 – 2.5 | 1.3 |
| Sihigher end in -17 coating types | ≤ 0.9 | 0.6 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cu | ≤ 0.75 | 0.1 |
| Fe | balance | — |
E309LMo-AW — frequently asked
What is E309LMo-AW used for?
E309LMo-AW is typically used for 316L to carbon steel transitions, clad/overlay welding on pressure vessels and chemical processing equipment. In short: standard 316L-to-steel filler; most corrosion-resistant 309 type; low-carbon overlay electrode.
What is the yield strength of E309LMo-AW?
E309LMo-AW has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 67% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is E309LMo-AW easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Weld deposit machines like 316L — gummy and strongly work-hardening; use sharp carbide, positive rake, heavy feed and flood coolant, avoid dwelling.
Can E309LMo-AW be welded?
Yes — weldability is rated excellent (90/100). SMAW with DCEP (AC also for -16/-17), short arc, stringer beads, interpass ≤150 °C; redry electrodes ~250–300 °C/1 h and keep ferrite 8–20 FN to avoid hot cracking.
What surface finishes work on E309LMo-AW?
Grind, pickle (HNO₃-HF paste) and passivate the deposit to restore the passive film; deposit is weakly magnetic so magnetic-particle testing is unreliable — use PT/UT.
Can E309LMo-AW be formed, bent or molded?
Not a wrought product; deposited overlay can be lightly ground/peened but not cold formed as such.
What is the maximum service temperature of E309LMo-AW?
E309LMo-AW is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E309LMo-AW and E309LMo PWHT?
AW is the default condition — default condition for dissimilar joints and buttering layers; deposit used directly after welding with 8–20 FN ferrite. PWHT: applies when the C-steel/low-alloy component must be stress relieved; expect some ferrite transformation, slight strength gain and toughness loss. Yield strength is 430 MPa in AW versus 440 MPa in PWHT.
Sources
- AWS A5.4/A5.4M — Stainless Steel Electrodes for Shielded Metal Arc Welding — American Welding Society (2012)
- ASME BPVC Section II Part C, SFA-5.4 — ASME (2023)
- EN ISO 3581 — Covered electrodes for manual metal arc welding of stainless and heat-resisting steels — ISO/CEN (2016)
- 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 consumable datasheets (ESAB / Böhler / Lincoln 309LMo types) — various (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.