Stainless Steel S38815 Annealed
Temper · default condition
UNS S38815
Standard stocked condition for acid-plant vessels, linings and fabricated parts; maximum corrosion resistance and formability.
Values for the Annealed condition
Other S38815 tempers and conditions
S38815 is listed in 2 conditions; see the grade overview at S38815.
- Annealed
- CW
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefaultThis page Annealed (solution annealed + pickled, sheet/plate) | Standard stocked condition for acid-plant vessels, linings and fabricated parts; maximum corrosion resistance and formability. | 300 | 640 | 40 | 180 HB | 1.7 % IACS |
Cold worked | Occasional supply where higher strength is needed; cold work must be limited and is usually followed by re-annealing for acid service. | 550 | 800 | 20 | 22 HRC | 1.7 % IACS |
What is S38815 Annealed?
S38815 Annealed is S38815 in the Annealed temper — standard stocked condition for acid-plant vessels, linings and fabricated parts; maximum corrosion resistance and formability. S38815 Annealed has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 68% of stainless steel grades. Elongation at break is 40% and the elastic modulus is 190 GPa (27.6 Msi). S38815 Annealed has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,350°C (2,462 °F).
Advantages
- Good corrosion resistance — 82/100, better than 90% of stainless steel grades
Limitations
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Poor heat conductor — 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 85% of stainless steel grades
- Difficult to weld — 40/100, worse than 83% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
S38815 Annealed properties
Typical room-temperature values for S38815 Annealed; 23 are specific to this condition. Other listed values are S38815 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
S38815 Annealed has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of stainless steel grades. It melts at 1,350°C (2,462 °F).
Mechanical16
S38815 Annealed has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 68% of stainless steel grades. Elongation at break is 40% and the elastic modulus is 190 GPa (27.6 Msi).
Thermal5
S38815 Annealed is rated for continuous service to 400°C (752 °F). It conducts heat at 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 85% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
S38815 Annealed conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 90% of stainless steel grades.
Sustainability4
Producing a kilogram of S38815 Annealed takes about 57 MJ of energy and emits 4.6 kg of CO₂ — more than 62% of stainless steel grades. Typical recycled content is 50%.
Manufacturability7
S38815 Annealed's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability fair (40/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S38815 Annealed
Is S38815 easy to machine?
Machine like a tough austenitic but expect abrasive wear from silicides: rigid setups, sharp carbide or coated inserts, low speed, heavy positive feed and copious coolant to avoid work hardening.
Can S38815 be welded?
GTAW/GMAW with matching high-Si or over-alloyed Ni-base filler, low heat input, no preheat, tight interpass control; high Si makes the weld pool hot-crack sensitive so avoid restraint and heavy weaves.
Can S38815 be formed, bent or molded?
Cold forms and rolls in the annealed condition with higher springback and less stretch than 304; hot working window is narrow (roughly 1050–1150 °C) followed by rapid cooling and solution anneal.
What surface finishes work on S38815?
Pickle and passivate after welding to restore the silica-rich film; grind/polish with fresh abrasives free of iron contamination — no anodising or plating is used.
S38815 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 weld corrosion resistance | ≤ 0.03 | 0.02 |
| Sikey element forming silica-rich passive film | 5 – 6 | 5.6 |
| Mn | ≤ 2 | 0.5 |
| P | ≤ 0.04 | — |
| S | ≤ 0.02 | — |
| Cr | 13 – 15 | 14 |
| Nistabilises austenite against high Si | 15 – 17 | 16 |
| Mo | 0.75 – 1.5 | 1.1 |
| Cuimproves reducing-acid behaviour | 0.75 – 1.5 | 1.1 |
| N | ≤ 0.03 | — |
| Fe | balance | — |
S38815 Annealed — frequently asked
What is S38815 Annealed used for?
S38815 Annealed is typically used for chemical process piping and fittings, acid-service tubing, chemical process vessel internals, machined valve and pump components, heat exchanger tubing and instrumentation fittings and nipples. In short: high-silicon austenitic grade; corrosion score 82/100; niche acid-service stainless.
What is the yield strength of S38815 Annealed?
S38815 Annealed has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 68% of stainless steel grades. Strength varies by condition: see the 2 listed tempers.
Is S38815 Annealed easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Machine like a tough austenitic but expect abrasive wear from silicides: rigid setups, sharp carbide or coated inserts, low speed, heavy positive feed and copious coolant to avoid work hardening.
Can S38815 Annealed be welded?
With care — weldability is rated fair (40/100). GTAW/GMAW with matching high-Si or over-alloyed Ni-base filler, low heat input, no preheat, tight interpass control; high Si makes the weld pool hot-crack sensitive so avoid restraint and heavy weaves.
What surface finishes work on S38815 Annealed?
Pickle and passivate after welding to restore the silica-rich film; grind/polish with fresh abrasives free of iron contamination — no anodising or plating is used.
Can S38815 Annealed be formed, bent or molded?
Cold forms and rolls in the annealed condition with higher springback and less stretch than 304; hot working window is narrow (roughly 1050–1150 °C) followed by rapid cooling and solution anneal.
What is the maximum service temperature of S38815 Annealed?
S38815 Annealed 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 S38815 Annealed and S38815-CW?
Annealed is the default condition — standard stocked condition for acid-plant vessels, linings and fabricated parts; maximum corrosion resistance and formability. CW: occasional supply where higher strength is needed; cold work must be limited and is usually followed by re-annealing for acid service. Yield strength is 300 MPa in Annealed versus 550 MPa in CW.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A213/A249 — Stainless Steel Boiler, Superheater and Heat-Exchanger Tubes — ASTM International (2022)
- UNS Metals & Alloys in the Unified Numbering System — SAE International / ASTM (2017)
- High-silicon austenitic stainless steel for concentrated sulfuric acid service — Sandvik Materials Technology (2020)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.