304L Austenitic Stainless Steel

Material Profile: 304L Austenitic Stainless Steel for Binder Jetting

Binder Jetting Engineering Material Technical Report Series

Compiled from manufacturer technical datasheets and peer-reviewed literature

Abstract—304L (UNS S30403) is the lower-cost cousin of 316L — same austenitic structure, same low-carbon discipline (≤ 0.030 wt% C), but without the 2–3 wt% Mo addition. It was qualified on the Desktop Metal Shop System in 2024 as the fifth Shop-system metal (joining 17-4PH, 316L, IN625, CoCr) and targets large-volume general-purpose stainless applications where 316L's chloride pitting resistance is not required. 304L is the most widely used stainless steel globally, and binder-jet 304L allows manufacturers to substitute 304L AM parts directly into existing 304L-qualified product lines without re-validation of corrosion behavior. Mechanical properties are similar to 316L: as-sintered UTS ≈ 540 MPa, yield ≈ 210 MPa, elongation ≥ 55 %.

Index Terms—additive manufacturing, binder jetting, 304L, austenitic stainless steel, Desktop Metal Shop System, UNS S30403.

I.  MATERIAL IDENTIFICATION

This section establishes the canonical names and commercial designations under which the material is supplied.

A.  Designation

Trade names: Desktop Metal 304L (Shop System); ExOne 304L; ASTM A276 / A479 / A480 (UNS S30403); AISI 304L; EN 1.4307 (X2CrNi18-9); W.Nr. 1.4307. AM-specific specification: ISO/ASTM 52907 powder feedstock guidance.

B.  Full Chemical Name

Low-carbon austenitic FCC chromium-nickel stainless steel. Composition (wt%): Cr 18.0–20.0, Ni 8.0–12.0, Mn ≤ 2.0, Si ≤ 1.0, P ≤ 0.045, S ≤ 0.03, N ≤ 0.10, C ≤ 0.030, Fe — balance. Single-phase austenite; non-magnetic. Pitting Resistance Equivalent Number (PREN) ≈ 18 (vs ~26 for 316L) — distinguishes it from 316L by absence of Mo.

C.  Aliases and Alternative Designations

II.  COMPOSITION AND MOLECULAR STRUCTURE

A.  Empirical Chemical Formula

Fe(balance) — Cr(18.0–20.0%) — Ni(8.0–12.0%) — Mn(≤2%) — Si(≤1%) — C(≤0.03%, the 'L' = low-carbon). Single-phase γ-Fe FCC austenite; non-magnetic; PREN ≈ 18.

Fig. 1.  Repeating unit / structural schematic of the polymer matrix.

Fig. 2.  Schematic of the single-phase polymer (no reinforcement).

B.  Composition Breakdown

TABLE I
 COMPOSITIONAL BREAKDOWN OF 304L SS (DESKTOP METAL SHOP SYSTEM) (TYPICAL / PER SUPPLIER DATASHEET)

III.  MECHANICAL PROPERTIES — XY BUILD DIRECTION (HORIZONTAL)

In the XY orientation the tensile load is applied parallel to the powder-bed plane. Binder-jetted (BJ) parts in the as-sintered state generally show modest in-plane vs build-axis anisotropy because sintering occurs near the solidus and re-distributes the porosity left by the binder-removal step. For metal BJ, post-sintering treatments (HIP, solution-anneal, age) are commonly applied to bring properties to wrought-equivalent and to eliminate residual closed porosity.

TABLE II
 MECHANICAL PROPERTIES — XY ORIENTATION (304L SS (DESKTOP METAL SHOP SYSTEM))

IV.  MECHANICAL PROPERTIES — Z BUILD DIRECTION (VERTICAL)

In the Z orientation the tensile load is applied perpendicular to the printed layers. Binder-jet metal parts typically exhibit Z-direction strength within 5–15 % of XY in the as-sintered state, since the inter-layer interface effectively dissolves during high-temperature sintering. For sand-mould materials, Z-direction strength is dominated by inter-layer binder bonding and is generally 60–90 % of XY in transverse strength.

TABLE III
 MECHANICAL PROPERTIES — Z ORIENTATION (304L SS (DESKTOP METAL SHOP SYSTEM))

Like 316L, binder-jet 304L is essentially isotropic after high-temperature sintering. The recrystallised austenite microstructure is dimensionally and mechanically uniform across XY and Z. Sensitisation precaution: do not hold parts in the 427–816 °C range during cooling; this applies equally to as-sintered and post-machined parts.

V.  RECOMMENDED PROCESS PARAMETERS

Values summarised below give consensus operating windows from public datasheets (Desktop Metal, ExOne, voxeljet, cprint3d). Specific machines and parameter sets may differ within ±10 %; the supplier's verified parameter sheet always supersedes this table. For metal binder jetting, complete green-state cure (~200 °C) and a high-temperature de-bind / sinter cycle (typically 1 100–1 380 °C in H₂ / Ar / vacuum) are mandatory after print. For sand binder jetting, parts are usable directly after print (with optional microwave or oven post-cure).

TABLE IV
 RECOMMENDED BINDER-JETTING PROCESS PARAMETERS FOR 304L SS (DESKTOP METAL SHOP SYSTEM)

VI.  GLASS TRANSITION TEMPERATURE (TG)

Reported / typical Tg: Not applicable (metallic alloy).

Critical thermal limits: sensitisation window 427–816 °C (avoid prolonged exposure); creep limit ≈ 760 °C (slightly lower than 316L due to absence of Mo); melting range 1400–1450 °C.

VII.  HEAT DEFLECTION TEMPERATURE (HDT)

Heat deflection temperature is the temperature at which a standard bar deflects 0.25 mm under a specified flexural load (ASTM D648 / ISO 75).

TABLE V
 HEAT DEFLECTION TEMPERATURE OF 304L SS (DESKTOP METAL SHOP SYSTEM) UNDER STANDARD TEST LOADS

VIII.  DISTINGUISHING CHARACTERISTICS AND STANDARDS

A.  Lower cost than 316L

Powder cost is approximately 15–20 % lower than 316L (no Mo), making 304L the entry-level binder-jet stainless choice when chloride pitting resistance is not critical. Suitable for indoor / freshwater / mildly humid environments.

B.  Same ductility, weldability, machinability as wrought 304L

TIG/MIG weldable with ER308L filler; machinable with conventional carbide tooling; passes ASTM A967 passivation procedures. BJ 304L parts integrate directly into existing 304L production lines and supply chains without specification changes.

C.  Limited corrosion in chlorides

PREN ≈ 18 (vs 26 for 316L) means 304L is unsuitable for marine, body-fluid contact, or chlorinated cleaning environments. For these, specify 316L. 304L is fine for atmospheric exposure, food contact (non-chloride), structural use.

D.  Non-magnetic

Like 316L, 304L is non-magnetic in fully austenitic state. Useful for MRI-compatible structural components and electromagnetic-shielding housings.

E.  Multi-system support

304L is qualified on Shop System, but Desktop Metal also supports it as a customer-qualified material on Production System P-50 and X-Series machines, providing scaling path from prototype to mass production using the same alloy chemistry.

IX.  REPRESENTATIVE APPLICATIONS

304L SS (Desktop Metal Shop System) is typically deployed in the following applications:

1)  Structural components: Brackets, flanges, frames in indoor / freshwater applications — direct AM substitution for machined 304L bar stock.

2)  Food processing equipment (non-chloride): Bowl sleds, racks, fixtures in dry / non-chlorinated food handling — leveraging electropolishability and ASTM A967 passivation.

3)  Fluid transfer components: Manifolds, pipe fittings, flow distributors for fresh water, low-chloride process fluids.

4)  Welded fabrications: Sub-assemblies that will be TIG/MIG welded into larger structures — 304L is the go-to weldable stainless.

5)  Architectural / decorative: Bespoke architectural fittings, decorative facades, custom signage hardware where polished stainless aesthetic is required.

X.  REFERENCES

[1]  Desktop Metal, “Desktop Metal and CETIM Qualify 304L Stainless Steel for Shop System,” Press release, 2024. [Online]. Available: https://www.digitalengineering247.com/article/desktop-metal-cetim-qualify-304l-stainless-steel/materials

[2]  ASTM A276/A276M-17, “Standard Specification for Stainless Steel Bars and Shapes,” 2017.

[3]  ASTM A480/A480M-22, “Standard Specification for General Requirements for Flat-Rolled Stainless and Heat-Resisting Steel Plate, Sheet, and Strip,” 2022.

[4]  ASTM A967/A967M-17, “Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts,” 2017.

[5]  EN 10088-3:2014, “Stainless steels — Part 3: Technical delivery conditions,” CEN.

[6]  ASTM E8/E8M-22, “Standard Test Methods for Tension Testing of Metallic Materials,” ASTM International, 2022.

[7]  ASTM B962-17, “Standard Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes' Principle,” ASTM International, 2017.

[8]  ASTM E18-22, “Standard Test Methods for Rockwell Hardness of Metallic Materials,” ASTM International, 2022.

[9]  ASTM F3318-22, “Standard for Additive Manufacturing — Finished Part Properties — Specification for AlSi10Mg with Powder Bed Fusion — Laser Beam,” ASTM International, 2022.

[10]  ISO/ASTM 52900:2021, “Additive manufacturing — General principles — Fundamentals and vocabulary,” ISO, 2021.

[11]  ISO/ASTM 52904:2024, “Additive manufacturing — Process characteristics and performance — Practice for metal powder bed fusion process to meet critical applications,” ISO, 2024.

[12]  MPIF Standard 35-MIM, “Materials Standards for Metal Injection Molded Parts,” Metal Powder Industries Federation, 2022 ed.

[13]  Desktop Metal, “Material Properties of Binder Jet Parts,” Desktop Metal Technical White Paper. [Online]. Available: https://www.desktopmetal.com/resources/material-properties-of-binder-jet-parts

[14]  Desktop Metal, “Why Binder Jetting?” Desktop Metal Application Note. [Online]. Available: https://www.desktopmetal.com/resources/why-binder-jetting-1

[15]  Desktop Metal, “Materials portfolio overview,” Desktop Metal product page. [Online]. Available: https://www.desktopmetal.com/materials/

(Image Source : Ervin Industries)