Stainless Steel S38815
UNS S38815
S38815 is a UNS-registered high-silicon austenitic stainless steel with elevated chromium and nickel, supplied annealed as plate and tube, as hot-rolled annealed bar, and in cold-worked condition.
Reference datasheet — S38815 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Annealed condition
S38815 tempers and conditions
S38815 is supplied in 2 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault 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 |
Supply forms, finishes and certifications
Ways S38815 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Annealed-Tube | Solution annealed seamless/welded tube | Supply form |
HR-Annealed-Bar | Hot rolled / forged + solution annealed bar and forgings | Supply form |
What is S38815?
S38815 is a UNS-registered high-silicon austenitic stainless steel with elevated chromium and nickel, supplied annealed as plate and tube, as hot-rolled annealed bar, and in cold-worked condition. Engineers specify it where standard 3xx chemistry cannot handle the service medium: it rates 82/100 for corrosion resistance while holding 300 MPa yield, 640 MPa tensile, 40 % elongation and about 180 HB (88 HRB). The silicon that builds the protective film also makes the alloy abrasive to machine (machinability 25/100) and hot-crack sensitive when welded, and formability is limited (45/100). Higher-nickel grades such as 904L or Alloy 20 are the usual alternatives. S38815 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). S38815 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).
What is S38815 used for?
- Chemical process piping and fittings
- Acid-service tubing
- Chemical process vessel internals
- Machined valve and pump components
- Heat exchanger tubing
- Instrumentation fittings and nipples
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 properties
Typical room-temperature values for S38815-Annealed; bars are the position among stainless steel grades.
Physical3
S38815 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 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 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 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 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'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. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. S38815 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S38815
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.
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 |
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.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
How much does S38815 cost?
S38815 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
S38815 — frequently asked
What is S38815 used for?
S38815 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?
S38815 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 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 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?
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 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?
S38815 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.
How much does S38815 cost?
S38815 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.