ASTM F3301
Standard for Additive Manufacturing—Post Processing Methods—Standard Specification for Thermal Post-Processing Metal Parts Made Via Powder Bed Fusion
Specification for thermal post-processing (stress relief, annealing, solution treatment, ageing and hot isostatic pressing) of metal parts made by powder bed fusion, covering process control, equipment, documentation and verification.
What ASTM F3301 specifies
ASTM F3301 fills the gap between the additive-manufacturing material specifications (F2924 Ti-6Al-4V, F3055 Inconel 718, F3184 316L, F3318 AlSi10Mg and others) and the heat treater: it states how the thermal post-processing those specifications call for must be performed and documented on powder-bed-fusion parts. It covers stress relief while the part is still on the build plate, annealing, solution and precipitation treatments, and hot isostatic pressing (HIP) to close porosity, requiring qualified furnace pyrometry (AMS 2750 or equivalent), atmosphere control appropriate to the alloy (vacuum or inert gas for titanium and nickel alloys, with limits on discoloration and alpha case), defined heat-treat lots, witness coupons built with the parts, and full records of temperature, time, pressure and cooling. Alloy-specific cycle parameters stay in the material specification or purchase order — for example F2924's HIP at 895–955 °C, 100 MPa minimum, 180 ± 60 min for Ti-6Al-4V — with F3301 governing how they are executed and verified.
Tests and the drawing call-out
Tests the document imposes
- Tensile test per ASTM E8/E8M on witness coupons built and heat treated with the parts
- Density / porosity by Archimedes method (ASTM B311) or metallographic image analysis after HIP
- Hardness per ASTM E18 / E10 / E384 as the material specification requires
- Metallographic examination of microstructure (ASTM E3 / E407) and alpha-case / oxidation check on titanium
- Interstitial chemistry after heat treatment (oxygen, nitrogen, hydrogen per ASTM E1409 / E1447) on reactive alloys
- Furnace TUS / SAT per AMS 2750; HIP pressure-temperature-time record
How to cite it
Drawing call-out
THERMAL POST-PROCESS PER ASTM F3301: STRESS RELIEVE ON PLATE, THEN HIP AND ANNEAL PER ASTM F2924; WITNESS COUPONS REQUIREDAngle brackets mark the choices the drawing must make; every finish page shows a completed example.
Heat treatments specified to ASTM F3301
| Treatment | Role | Cost |
|---|---|---|
Hot isostatic pressing applies high-temperature inert gas pressure uniformly to cast, sintered, and metal powder-bed-fusion parts. | Governing | $$$$ |
Solution Treat + Age (Ti) is a precipitation-hardening condition for Ti-6Al-4V and Ti-6Al-6V-2Sn and Ti-10V-2Fe-3Al. | Related | $$$$ |
ASTM F3301 — frequently asked
Why stress relieve before removing the part from the plate?
Laser powder-bed builds carry residual stresses that approach the yield strength; cutting an unrelieved Ti-6Al-4V or 718 part off the plate lets it spring and can crack thin features. F3301 requires the stress relief to be performed as specified before plate removal, in vacuum or argon for titanium so the surface does not oxidise.
What does HIP do for a printed part?
Simultaneous high temperature (roughly 900–1200 °C depending on alloy) and gas pressure of 100 MPa or more collapses internal porosity and lack-of-fusion voids, raising fatigue life several-fold and reducing scatter; it cannot close surface-connected pores. The material specification sets the cycle (Ti-6Al-4V: 895–955 °C, 100 MPa minimum, 2–4 h); F3301 controls the equipment, gas purity and records.
Are witness coupons mandatory?
Yes, whenever the material specification or purchase order requires mechanical-property acceptance: coupons are built on the same plate in the same run, travel through every thermal step with the parts and are tested per ASTM E8 and by metallography. Coupons from another build or another furnace load do not represent the lot.
Can a conventional heat treater process AM parts under F3301?
Yes, if the furnace pyrometry meets AMS 2750, the atmosphere suits the alloy (titanium needs vacuum or high-purity argon; 316L and 718 tolerate vacuum or inert gas) and the shop keeps the lot traceability and records F3301 requires. HIP is normally a specialised subcontract step with its own qualification.
ASTM F3301 is copyrighted by ASTM International. This page explains the document so a drawing can be read; it does not reproduce the standard. Purchase the current edition from the publisher. Official source ↗