Stainless Steel S44735
UNS S44735 · EN 1.4736, 1.4592
S44735 (AL 29-4C) is a Ti/Nb-stabilized 29Cr-4Mo super-ferritic stainless steel; the stabilization suppresses chromium-carbide sensitization, so welded joints keep base-metal corrosion resistance.
Reference datasheet — S44735 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
S44735 tempers and conditions
S44735 is supplied in one standard condition, Annealed. Annealed is the default FabDigit quotes; the values on this page are for it.
Supply forms, finishes and certifications
Ways S44735 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Welded Tube Annealed | Welded tube, bright/mill annealed | Supply form |
CRA-2B | Cold rolled, annealed, pickled sheet/strip | Surface finish |
HRAP | Hot rolled, annealed, pickled plate | Surface finish |
What is S44735?
S44735 (AL 29-4C) is a Ti/Nb-stabilized 29Cr-4Mo super-ferritic stainless steel; the stabilization suppresses chromium-carbide sensitization, so welded joints keep base-metal corrosion resistance. Engineers select it for seawater and brine heat-exchanger duty because of its pitting and crevice resistance (corrosion score 88) and resistance to chloride stress-corrosion cracking, and it is supplied as welded tube, cold-rolled 2B sheet and hot-rolled annealed pickled plate. Annealed values are 480 MPa yield, 590 MPa tensile, 27% elongation and about 90 HRB, with service capped at 300 °C and formability (score 55) below austenitic grades. S44800 is the nearest alternative where higher purity is required. S44735 has a density of 7.67 g/cm³ (0.277 lb/in³), lighter than 95% of stainless steel grades. It melts at 1,425°C (2,597 °F). S44735 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
What is S44735 used for?
- seawater condenser tubing
- desalination equipment
- pulp bleach plants
Advantages
- Good corrosion resistance — 88/100, better than 97% of stainless steel grades
- High strength — 480 MPa (69.6 ksi), better than 75% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
S44735 properties
Typical room-temperature values for S44735-Annealed; bars are the position among stainless steel grades.
Physical3
S44735 has a density of 7.67 g/cm³ (0.277 lb/in³), lighter than 95% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical13
S44735 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 75% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
Thermal5
S44735 is rated for continuous service to 300°C (572 °F). It conducts heat at 16.5 W/m·K (9.53 BTU/hr·ft·°F), better than 70% of stainless steel grades. Thermal expansion is 10.1 µm/m·K (5.61 µin/in·°F).
Electrical3
S44735 conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 97% of stainless steel grades.
Sustainability4
Producing a kilogram of S44735 takes about 62 MJ of energy and emits 5 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 50%.
Manufacturability7
S44735's machinability is fair (35/100, better than 51% of stainless steel grades); weldability very good (70/100); formability good (55/100).
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. S44735 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S44735
Is S44735 easy to machine?
Machines like a tough 4% Mo ferritic: rigid setups, sharp positive-rake carbide, slow speeds and heavy positive feed to cut under the work-hardened skin, generous coolant.
Can S44735 be welded?
GTAW/GMAW/plasma with high-purity argon (add He, keep O₂/N₂ pickup low), autogenous or matching stabilized filler, or Ni-base filler (622/59); low heat input, interpass <150 °C, no preheat, no post-weld sensitization anneal required.
Can S44735 be formed, bent or molded?
Roll form, bend and tube-mill readily at ambient temperature with generous radii (≈2t); limited stretch/deep-draw capability and higher springback than austenitics — warm forming near 100–200 °C helps.
S44735 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 interstitials essential for toughness | ≤ 0.03 | 0.02 |
| Mn | ≤ 1 | 0.3 |
| Si | ≤ 1 | 0.4 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0 |
| Cr | 28 – 30 | 29 |
| Ni | ≤ 1 | 0.3 |
| Mo | 3.6 – 4.2 | 3.9 |
| N | ≤ 0.05 | 0.02 |
| Ti+Nband ≥ 6×(C+N); dual stabilization | 0.2 – 1 | 0.45 |
| Fe | balance |
What surface finishes work on S44735?
Pickle/passivate after hot work and welding to restore the passive film; electropolishes and mechanically polishes well; do not anodize.
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
Equivalent designations
Standards and trade names that resolve to Stainless Steel S44735 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does S44735 cost?
S44735 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
S44735 — frequently asked
What is S44735 used for?
S44735 is typically used for seawater condenser tubing, desalination equipment and pulp bleach plants. In short: weldable super-ferritic grade; seawater tubing without nickel; no post-weld anneal.
What is the yield strength of S44735?
S44735 has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 75% of stainless steel grades.
Is S44735 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machines like a tough 4% Mo ferritic: rigid setups, sharp positive-rake carbide, slow speeds and heavy positive feed to cut under the work-hardened skin, generous coolant.
Can S44735 be welded?
Yes — weldability is rated very good (70/100). GTAW/GMAW/plasma with high-purity argon (add He, keep O₂/N₂ pickup low), autogenous or matching stabilized filler, or Ni-base filler (622/59); low heat input, interpass <150 °C, no preheat, no post-weld sensitization anneal required.
What surface finishes work on S44735?
Pickle/passivate after hot work and welding to restore the passive film; electropolishes and mechanically polishes well; do not anodize.
Can S44735 be formed, bent or molded?
Roll form, bend and tube-mill readily at ambient temperature with generous radii (≈2t); limited stretch/deep-draw capability and higher springback than austenitics — warm forming near 100–200 °C helps.
What is the maximum service temperature of S44735?
S44735 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does S44735 cost?
S44735 is a high-cost stainless steel ($$$$), 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 A268/A268M — Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing — ASTM International (2022)
- ASTM A803/A803M — Welded Ferritic Stainless Steel Feedwater Heater Tubes — ASTM International (2021)
- AL 29-4C Alloy (UNS S44735) Technical Data Sheet — ATI (Allegheny Technologies) (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- / (SMM / Mysteel / 1688) (2025)
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.