Stainless Steel 1.4855 AC+SR
Heat-treated state
EN 1.4855
AC+SR = as-cast plus stress relief / homogenizing anneal
Specified for weld-fabricated or heavily machined assemblies where casting/welding residual stress could cause distortion or thermal-fatigue cracking in service.
Values for the AC+SR condition
Other 1.4855 tempers and conditions
1.4855 is listed in 3 conditions; see the grade overview at 1.4855.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AC+SRThis page As-cast plus stress relief / homogenizing anneal | Specified for weld-fabricated or heavily machined assemblies where casting/welding residual stress could cause distortion or thermal-fatigue cracking in service. | 240 | 455 | 13 | 180 HB | 1.9 % IACS |
ACDefault Spheroidize annealed | Standard supply condition for tube supports, hangers, hearth parts and general heat-resistant castings; no heat treatment, EN 10295 mechanical minima apply. | 250 | 470 | 10 | 190 HB | 1.9 % IACS |
As-welded deposit | Reference condition for weld-metal and repair-welded zones; Nb stabilization makes this grade more crack-tolerant to repair welding than HK40. | 260 | 450 | 8 | 195 HB | 1.9 % IACS |
What is 1.4855 AC+SR?
1.4855 AC+SR is 1.4855 heat treated to AC+SR — specified for weld-fabricated or heavily machined assemblies where casting/welding residual stress could cause distortion or thermal-fatigue cracking in service. 1.4855 AC+SR has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 455 MPa (66 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 175 GPa (25.4 Msi). 1.4855 AC+SR has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,340°C (2,444 °F). AC is the default condition FabDigit quotes; AC+SR is available on request or by drawing note.
Advantages
- High service temperature — 1,100°C (2,012 °F), better than 96% of stainless steel grades
Limitations
- Low stiffness — 175 GPa (25.4 Msi), worse than 99% of stainless steel grades
- Low strength — 240 MPa (34.8 ksi), worse than 96% of stainless steel grades
- Hard to polish — 45/100, worse than 96% of stainless steel grades
- Limited ductility — 13%, worse than 93% of stainless steel grades
- Limited formability — 12/100, worse than 93% of stainless steel grades
1.4855 AC+SR properties
Typical room-temperature values for 1.4855 AC+SR; 21 are specific to this condition. Other listed values are 1.4855 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4855 AC+SR has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,340°C (2,444 °F).
Mechanical16
1.4855 AC+SR has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 455 MPa (66 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 175 GPa (25.4 Msi).
Thermal6
1.4855 AC+SR is rated for continuous service to 1,100°C (2,012 °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 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.4855 AC+SR conducts electricity at 1.9 % IACS, worse than 84% of stainless steel grades.
Chemical & Environmental2
Corrosion resistance is good (64/100), better than 54% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4855 AC+SR takes about 55 MJ of energy and emits 4.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
1.4855 AC+SR's machinability is poor (27/100, worse than 83% of stainless steel grades); weldability good (58/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4855 AC+SR
Is 1.4855 easy to machine?
Machine with rigid setups, positive-rake carbide (or ceramic for skin cuts), low speed/heavy feed and flood coolant; hard NbC/Cr carbides abrade edges and the austenite work-hardens if the tool dwells.
Can 1.4855 be welded?
GTAW/SMAW with matching 24-24Nb or Ni-base (ERNiCr-3 / 25-35Nb) filler, preheat 150–250 °C, low heat input and no post-weld quench; service-aged parts should be re-solution annealed or buttered before repair welding.
Can 1.4855 be formed, bent or molded?
Cast to shape only (static sand/investment or centrifugal); allow generous fillets, 3–5 % solidification shrinkage risers and gradual wall transitions to avoid hot tears.
What surface finishes work on 1.4855?
Sand/shot blast plus pickle-passivate for scale removal; no anodizing — a self-forming Cr/Si oxide scale is the working surface, and aluminizing or diffusion coatings can be added for carburizing service.
1.4855 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 |
|---|---|---|
| Cprimary carbide former, gives creep strength | 0.3 – 0.5 | 0.4 |
| Sioxidation resistance and casting fluidity | 1 – 2.5 | 1.7 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cr | 23 – 25 | 24 |
| Ni | 23 – 25 | 24 |
| Nbstabilizing carbide former (MC/NbC) | 1.2 – 1.8 | 1.5 |
| Fe | balance | — |
1.4855 AC+SR — frequently asked
What is 1.4855 AC+SR used for?
1.4855 AC+SR is typically used for petrochemical radiant tubes, furnace roller and fixture castings and high-temperature fittings. In short: intermediate HK/HP alternative; nb-stabilized 24Cr-24Ni; good thermal fatigue life.
What is the yield strength of 1.4855 AC+SR?
1.4855 AC+SR has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 455 MPa (66 ksi) — weaker than 96% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 1.4855 AC+SR easy to machine?
Not especially — machinability is rated poor (27/100, worse than 83% of stainless steel grades). Machine with rigid setups, positive-rake carbide (or ceramic for skin cuts), low speed/heavy feed and flood coolant; hard NbC/Cr carbides abrade edges and the austenite work-hardens if the tool dwells.
Can 1.4855 AC+SR be welded?
Yes — weldability is rated good (58/100). GTAW/SMAW with matching 24-24Nb or Ni-base (ERNiCr-3 / 25-35Nb) filler, preheat 150–250 °C, low heat input and no post-weld quench; service-aged parts should be re-solution annealed or buttered before repair welding.
What surface finishes work on 1.4855 AC+SR?
Sand/shot blast plus pickle-passivate for scale removal; no anodizing — a self-forming Cr/Si oxide scale is the working surface, and aluminizing or diffusion coatings can be added for carburizing service.
Can 1.4855 AC+SR be formed, bent or molded?
Cast to shape only (static sand/investment or centrifugal); allow generous fillets, 3–5 % solidification shrinkage risers and gradual wall transitions to avoid hot tears.
What is the maximum service temperature of 1.4855 AC+SR?
1.4855 AC+SR is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4855-AC and 1.4855-AW?
AC is the default condition — standard supply condition for tube supports, hangers, hearth parts and general heat-resistant castings; no heat treatment, EN 10295 mechanical minima apply. AW: reference condition for weld-metal and repair-welded zones; Nb stabilization makes this grade more crack-tolerant to repair welding than HK40. Yield strength is 250 MPa in AC versus 260 MPa in AW.
Sources
- EN 10295 — Heat resistant steel castings — CEN (2002)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Heat-Resistant Castings) — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (High-temperature corrosion of Fe-Cr-Ni castings) — ASM International (2005)
- Heat-resistant cast alloy datasheets for reformer and radiant tube grades (HK/HP/24-24Nb class) — Foundry producers (e.g. Schmidt+Clemens, Paralloy-type data) (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.