Steel 316LSi-SR (Stress relieved)
Heat-treated state
AISI/SAE ER316LSi · ISO G 19 12 3 L Si
Low-temperature stress relief for dimensionally sensitive WAAM parts where full solution annealing (distortion) is unacceptable.
Values for the SR condition
Other 316LSi tempers and conditions
316LSi is listed in 4 conditions; see the grade overview at 316LSi.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed after deposition | Choose when maximum ductility, homogeneity and corrosion resistance are needed and residual stress must be removed from a WAAM part. | 250 | 520 | 55 | 150 HB | 2.4 % IACS |
Wire-arc additive, as-built deposit | Multi-layer arc-deposited block/wall; expect columnar grains and modest anisotropy between build and travel directions. | 330 | 545 | 45 | 170 HB | 2.3 % IACS |
SRThis page Stress relieved | Low-temperature stress relief for dimensionally sensitive WAAM parts where full solution annealing (distortion) is unacceptable. | 350 | 560 | 45 | 165 HB | 2.3 % IACS |
AWDefault As-welded deposit | Standard condition for GMAW/GTAW joints made with ER316LSi; use for typical fabricated stainless weldments. | 400 | 580 | 40 | 175 HB | 2.3 % IACS |
What is 316LSi-SR?
316LSi-SR is 316LSi heat treated to SR — low-temperature stress relief for dimensionally sensitive WAAM parts where full solution annealing (distortion) is unacceptable. 316LSi-SR has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 74% of steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi). 316LSi-SR has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 94% of steel grades. It melts at 1,390°C (2,534 °F). AW is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 45%, better than 100% of steel grades
- Good corrosion resistance — 76/100, better than 100% of steel grades
- Tough — resists crack growth — 170 MPa·√m (154.7 ksi·√in), better than 98% of steel grades
- Readily welded — 92/100, better than 93% of steel grades
- Forms and bends easily — 80/100, better than 93% of steel grades
Limitations
- Poor heat conductor — 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 98% of steel grades
- Low electrical conductivity — 2.3 % IACS, worse than 98% of steel grades
- High embodied carbon — 5.2 kg CO₂/kg, worse than 96% of steel grades
316LSi-SR properties
Typical room-temperature values for 316LSi-SR; 22 are specific to this condition. Other listed values are 316LSi reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
316LSi-SR has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 94% of steel grades. It melts at 1,390°C (2,534 °F).
Mechanical16
316LSi-SR has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 74% of steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
316LSi-SR is rated for continuous service to 450°C (842 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 98% of steel grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
316LSi-SR conducts electricity at 2.3 % IACS, worse than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is very good (76/100), better than 100% of steel grades.
Sustainability4
Producing a kilogram of 316LSi-SR takes about 56 MJ of energy and emits 5.2 kg of CO₂ — more than 95% of steel grades. Typical recycled content is 70%.
Manufacturability8
316LSi-SR's machinability is fair (43/100, worse than 71% of steel grades); weldability excellent (92/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 316LSi-SR
Is 316LSi easy to machine?
Gummy, work-hardening austenitic deposit — use sharp positive-rake carbide, rigid setups, high feed/low speed and flood coolant; WAAM porosity/silicate inclusions can chip edges.
Can 316LSi be welded?
Excellent GMAW/GTAW behaviour with Ar+2%CO₂ or Ar+2%O₂ (pure Ar for TIG); keep interpass below ~150 °C, control heat input, and remove silicate islands between passes in multi-pass welds.
Can 316LSi be formed, bent or molded?
As-deposited material is ductile and cold-formable, but heavy cold work raises strength quickly and induces strain-induced martensite; anneal at ~1050 °C for severe forming.
What surface finishes work on 316LSi?
Grind/machine to remove build layer ridges, then pickle-passivate (ASTM A967) or electropolish; no anodising — high Si can leave slightly duller weld surfaces than 316L.
316LSi 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 for sensitisation resistance | ≤ 0.03 | 0.02 |
| Cr | 18 – 20 | 19 |
| Ni | 11 – 14 | 12.3 |
| Mo | 2 – 3 | 2.5 |
| Mn | 1 – 2.5 | 1.7 |
| Sithe 'Si' addition: improves wetting and arc stability | 0.65 – 1 | 0.85 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cu | ≤ 0.75 | 0.2 |
| Nnot limited in all standards | ≤ 0.08 | 0.04 |
| Fe | balance | — |
316LSi-SR — frequently asked
What is 316LSi-SR used for?
316LSi-SR is typically used for WAAM stainless builds, pipe welding and tank fabrication. In short: best-wetting 316L wire; standard WAAM stainless feedstock; low-carbon, Mo-bearing deposit.
What is the yield strength of 316LSi-SR?
316LSi-SR has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is 316LSi-SR easy to machine?
Not especially — machinability is rated fair (43/100, worse than 71% of steel grades). Gummy, work-hardening austenitic deposit — use sharp positive-rake carbide, rigid setups, high feed/low speed and flood coolant; WAAM porosity/silicate inclusions can chip edges.
Can 316LSi-SR be welded?
Yes — weldability is rated excellent (92/100). Excellent GMAW/GTAW behaviour with Ar+2%CO₂ or Ar+2%O₂ (pure Ar for TIG); keep interpass below ~150 °C, control heat input, and remove silicate islands between passes in multi-pass welds.
What surface finishes work on 316LSi-SR?
Grind/machine to remove build layer ridges, then pickle-passivate (ASTM A967) or electropolish; no anodising — high Si can leave slightly duller weld surfaces than 316L.
Can 316LSi-SR be formed, bent or molded?
As-deposited material is ductile and cold-formable, but heavy cold work raises strength quickly and induces strain-induced martensite; anneal at ~1050 °C for severe forming.
What is the maximum service temperature of 316LSi-SR?
316LSi-SR is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 316LSi-AW and 316LSi-SA?
AW is the default condition — standard condition for GMAW/GTAW joints made with ER316LSi; use for typical fabricated stainless weldments. SA: choose when maximum ductility, homogeneity and corrosion resistance are needed and residual stress must be removed from a WAAM part. Yield strength is 400 MPa in AW versus 250 MPa in SA.
Sources
- AWS A5.9/A5.9M — Bare Stainless Steel Welding Electrodes and Rods (ER316LSi) — AWS (2017)
- EN ISO 14343 — Welding consumables, wire electrodes for arc welding of stainless steels (G 19 12 3 L Si) — ISO (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ER316LSi solid wire all-weld-metal datasheets (ESAB / Böhler / Lincoln Electric) — various (2023)
- Published WAAM 316L/316LSi mechanical property studies (as-built and solution-annealed) — peer-reviewed literature (2022)
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.